Luminescent device

专利摘要:
PURPOSE: A luminescent device is provided to enhance mobility of a carrier by mitigating an energy barrier in an organic compound layer. CONSTITUTION: A luminescent device including an organic luminescent element comprises an anode(3403), a cathode(3405) and a hole transporting layer provided between the anode and the cathode, including a first compound and a second compound. The first compound is smaller in ionization potential than the second compound, and the second compound is larger in hole mobility than the first compound.
公开号:KR20020055416A
申请号:KR1020010085934
申请日:2001-12-27
公开日:2002-07-08
发明作者:세오사토시；야마자키슈운페이
申请人:야마자끼 순페이；가부시키가이샤 한도오따이 에네루기 켄큐쇼；
IPC主号:

专利说明:

Luminescent device
[38] The present invention relates to an organic luminescent element having an anode and a cathode and a film (hereinafter referred to as an organic compound layer) comprising an organic compound adapted to emit light by application of an electric field. It relates to a light emitting device using. In particular, the present invention relates to a light emitting device using an organic light emitting element having a lower driving voltage and a longer lifetime than before. In addition, the term light emitting device described in the specification of the present application refers to a light emitting device or an image display device using an organic light emitting element as a light emitting element. In addition, the light emitting device may be a module having a connector such as an anisotropic conductive film (FPC), a tape automated bonding (TAB) tape, or a tape carrier package (TCP) installed in an organic light emitting device, a printed circuit at the end of the TAB tape or TCP. The module includes a module provided with a board and an integrated circuit (IC) in which a chip on glass (COG) system is directly installed in an organic light emitting device.
[39] The organic light emitting device is adapted to emit light when an electric field is applied. The light emitting mechanism is composed of an organic compound layer interposed between electrodes, and when a voltage is applied, electrons filled from the cathode and holes filled from the anode are recombined together at the emission center of the organic compound layer to excite molecules (hereinafter referred to as "molecules"). To form an exciton, and to discharge energy to create luminescence when the molecular excitons return to the ground state.
[40] In addition, the kind of molecular excitons formed by the organic compound includes a single excited state and a triple excited state, but the specification of the present invention includes a case in which any of the excited states contributes to light emission.
[41] In such an organic light emitting device, the organic compound layer is typically formed of a thin film of 1 μm or less. In addition, since the organic light emitting device emits light by itself, there is no need for a back light used in a conventional liquid crystal display. Thus, the organic light emitting element can be very advantageously formed very thin and light.
[42] When the organic compound layer has a thickness of, for example, about 100 to 200 nm, recombination occurs within several tens of nsec based on the mobility of the carrier in the organic compound layer. Although processing from carrier recombination to luminescence is considered, the organic light emitting device can be ready for luminescence in the order of several μsec. Therefore, fast response is also one of the characteristics of the organic light emitting device.
[43] Since the organic light emitting device is a carrier-filling type, it can be driven by a DC voltage, so that little noise is generated. For the drive voltage, a sufficient brightness of 100 cd / m ² first makes the thickness of the organic compound layer a uniform ultra thin film of about 100 nm, selects the electrode material to reduce the carrier charge barrier for the organic compound layer, and also single hetero (hetero) structure at 5.5 V by introducing (Reference 1: CW Tang and SA VanSlyke, "Organic Electroluminescent Diodes", Applied Physics Letters, vol. 51, no. 12, 913 -915 (1987)).
[44] With the same performance as thin, light, fast response and driving at DC low voltage, organic light emitting devices have attracted attention as next generation flat panel display devices. In addition, since the organic light emitting device is self-luminous and has a large viewing angle, it is considered to be relatively good in terms of visibility and effective as a device used for the display of portable equipment.
[45] In the configuration of the organic light emitting device described in Reference 1, the carrier charging barrier is smaller compared to the organic compound layer by improving the electron injection property by using a relatively stable Mg: Ag alloy of low working function as the cathode. This makes it possible to fill a very large number of carriers in the organic compound layer.
[46] In addition, carrier recombination efficiency is exponential because of the application of a single heterostructure in which a hole transport layer composed of a diamine compound and an electron transport emission layer composed of Alq ₃ (tris (8-quinolinolate) aluminum complex) are stacked in an organic compound layer. Is improved, as described later.
[47] For example, in the case of an organic light emitting device having only a single Alq ₃ layer, most of the electrons charged from the cathode reach the anode without recombination with the holes, and the Alq ₃ is electron transporting property, thereby making the luminous efficiency very low. That is, in order for a single layer of organic light emitting device to emit light efficiently (to drive at a low voltage), a material capable of transporting both electrons and holes in a well-balanced manner (hereinafter referred to as "bipolar material") Need to be used, and Alq ₃ does not meet its requirements.
[48] However, with the application of a single heterostructure as in Reference 1, the electrons charged from the cathode are blocked at the interface between the hole transport layer and the electron transport light emitting layer, and are enclosed in the electron transport light emitting layer. Thus, the carrier is effectively recombined in the electron transporting light emitting layer to provide sufficient light emission.
[49] When this concept of carrier blocking function is developed, it is possible to control the carrier recombination region. For example, it has been reported that the hole transport layer has a shine by inserting a hole blocking layer (hole blocking layer) between the hole transport layer and the electron transport layer and trapping the holes in the hole transport layer. (Reference 2: Yasunori KIJIAM, Nobutoshi ASAI and Shin-ichiro TAMURA, "A Blue Organic Light Emitting Diode", Japanese Journal of Applied Physics, vol. 38, 5274-5277 (1999)).
[50] Further, it can be said that the organic light emitting element described in Reference 1 is based on the functional separation in which the hole transporting layer is designated to transport holes and the electron transporting light emitting layer is designated to transport electrons to emit light. The concept of separating functions is further grown with the concept of a double heterostructure (3-layer structure) in which a light emitting layer is inserted between the hole transport layer and the electron transport layer (see 4: Chihaya ADACHI, Shizuo TOKITO, Tetsuo TSUTSUI, and Shogo SAITO). "Electroluminescence in Organic Films with Three-layered Structure", Japanese Journal of Applied Physics, Vol. 27, No. 2, L269-L271 (1988).
[51] This separation of functions has the advantage that one kind of organic material does not have to have various functions (such as luminescence, carrier transport, and carrier charging from an electrode) at one time, providing a wide degree of freedom in molecular design, for example (eg There is no need to find bipolar materials unreasonably). That is, by combining materials having good luminescence properties and carrier transport functions, respectively, high luminescence efficiency can be easily obtained.
[52] Because of these advantages, the concept of the laminated structure itself (carrier blocking function or functional separation) described in References 1 to 4 is widely used so far.
[53] However, because there are junctions between different kinds of materials (particularly, junctions between insulating materials), the laminate structure described above necessarily creates an energy barrier at the interface of the materials. The presence of an energy barrier prevents the movement of carriers at the interface, thus causing two problems.
[54] One problem is that the driving voltage is further reduced by the energy barrier. In fact, for current organic light emitting devices, single layer devices using conjugated polymers are reported to be superior in driving voltage and retain top data at power efficiency in lm / w (single excitation). (Comparative 4: Tetsuo Tsutsui, Journal of Organic Molecular Electronics and Bioelectronics Division of The Japan Society of Applied Physics, vol. 11, no. 1, p. 8 (2000)).
[55] In addition, the composite polymer described in Reference 4 is a bipolar material, which can provide the same level of carrier recombination efficiency as the material of the laminated structure. Thus, if the monolayer structure can provide the same level of carrier recombination efficiency by other methods or by using bipolar materials without using the laminate structure, the drive voltage is actually a single layer with less interface than in the laminate structure. Lower in structure.
[56] This is due to the fact that the driving voltage is necessarily higher because the movement of carriers at the interface between each layer in the organic compound layer (e.g. between the hole transport layer and the light emitting layer, hereinafter referred to as "organic interface") is prevented. Can be explained.
[57] For example, there is a method of enhancing carrier charging properties such that a material that mitigates the energy barrier is inserted at the interface between the electrode and the organic compound layer to lower the driving voltage (see 5: Takeo Wakimoto, Yoshinori Fukuda, Kenichi Nagayama, Akira). Yokoi, Hitoshi Nakada, and Masami Tsuchida, "Organic EL Cells Using Alkaline Metal Compounds as Electron Injection Materials", IEEE TRANSACTIONS ON ELECTRON DEVICES, vol. 44, no. 8, 1245-1248 (1997). In Reference 5, the drive voltage was successfully lowered using LiO2 as the electron injection layer.
[58] However, there are areas where carrier movement of the organic interface has not been solved, which is important for lowering the driving voltage in a single layer structure using bipolar material.
[59] In addition, another problem caused by the energy barrier layer is the effect on the life of the organic light emitting device. That is, the movement of the carrier is hindered and the luminance is lowered due to the accumulation of charge.
[60] Although there is no theory defined for this mechanism of deformation, it is reported that the degradation can be limited by inserting a hole injection layer between the anode and the hole transport layer and AC driving with a square wave instead of DC driving (Ref. 6: SA). VanSylke, CH Chen, and CW Tang, "Organic electroluminescent devices with improved stability", Applied Physics Letters, Vol. 69, No. 15, 2160-2162 (1996). This can be said to provide experimental evidence that the decrease in brightness can be limited by preventing the accumulation of charge through insertion of the hole injection layer and AC drive.
[61] From the above, the stacked structure can easily promote carrier recombination efficiency on the one hand and broaden the choice of materials in terms of functional separation, but on the other hand the formation of many organism interfaces (especially for carrier recombination) Formation of an organic interface that inhibits the movement of the carrier) may be said to impede the movement of the carrier and affect the driving voltage and brightness.
[62] The present invention improves carrier mobility by maximizing the advantages (separation of function) in the conventionally used laminated structure and mitigating the energy barrier applied to the organic layer, and lowering the driving voltage and extending the lifespan than in the prior art. The purpose is to provide an element.
[63] In particular, the present invention eliminates the organic interface given to the organic compound layer, improves the mobility of the carrier, and at the same time by fabricating a device having a concept different from that of the conventionally stacked structure in which the carrier of the light emitting layer is prevented for recombination. It aims to realize the functions of many different materials in the same way as the functional separation involved.
[64] In addition, the present invention has an object to provide a light emitting device having a lower driving voltage and longer life than in the prior art by using such an organic light emitting device. It is also an object of the present invention to provide an electronic product which is manufactured with the use of such a light emitting device, which consumes less power and lasts for a longer time than in the prior art.
[65] Mitigation of the energy barrier in the laminate structure is remarkably found in the insertion technology of the carrier filling layer as described in reference 5. The hole injection layer is best described using the energy band diagram of FIG. 1B.
[66] In FIG. 1A, the anode 101 and the hole injection layer 102 are directly bonded to each other, in which case the energy barrier 104 associated with the anode 101 and the hole injection layer 102 is large. However, the energy barrier is characterized by a hole injection layer with a material having a highest iccupied molecular orbital (HOMO) located between the ionization potential of the anode (the same as the working function for metals) and the HOMO level of the hole transport layer. By inserting into 103 it can be designed in a stepwise manner (FIG. 1B).
[67] Designing a stepped energy barrier as shown in FIG. 1B makes it possible to enhance the charging characteristics of the carrier from the cathode and to lower the drive voltage to some extent. However, increasing the number of layers raises the problem of increasing the number of organic interfaces. This is believed to be responsible for the fact that the single layer structure holds the top data in drive voltage and power efficiency as described in Reference 4.
[68] On the contrary, by overcoming this problem, it is possible to match the driving voltage and power efficiency in a single layer structure while making the most of the advantages in the laminated structure (various materials can be combined and no complex molecular design is required).
[69] The basic idea is not to increase the number of organic interfaces and to mitigate the energy barriers imparted to the organic compound layer and to suppress the movement of carriers. The inventor has devised a device structure which can realize the concept in the following manner.
[70] First, a method of mitigating the energy barrier for a hole is a layer obtained by mixing together a high HOMO level (low ionization potential) hole injection material and a high hole mobility hole transport material (hereinafter referred to as "hole transport mixed layer"). To provide. In this way, it is possible for a single layer to realize the function of two layers including a conventional hole injection layer and a conventional hole transport layer, so that in the hole transport mixed layer, the hole injection material operates to receive holes from the anode side and the hole transport The material operates to carry the hole.
[71] It is also desirable to form a concentration gradient in the hole transporting mixed layer described above. That is, as shown in FIG. 2, the proportion of hole injection material is increased toward the anode, and the proportion of hole transport material is increased as it moves away from the anode. Due to the formation of this concentration gradient, the holes are smoothed from the anode side and transported without generating a large energy barrier, which contributes to lowering the driving voltage and extending the life.
[72] In addition, although a straight line is used in FIG. 2 to indicate the concentration gradient for convenience, it is not necessary to be limited to the straight line as such, and it is sufficient that the concentration gradient is formed to decrease or increase. Indeed, in many cases, the concentration gradient is considered to be defined as a curve in control. The same is true for the other concentration gradients described herein in this application.
[73] The method of mitigating the energy barrier to electrons is then by mixing together an electron injecting material having a low level (high electron similarity) of the lowest unoccupied molecular orbit (LUMO) and an electron transporting material of high electron mobility. To provide the obtained layer (hereinafter referred to as the "electron transport mixed layer"). This method enables a single layer to realize the functions of two layers, including a conventional electron injection layer and a conventional electron transport layer, so that in the electron transport mixed layer, the electron injection material is operated to receive electrons from the cathode side. And the electron transport material carries electrons.
[74] It is also desirable to form the concentration gradient in the above-mentioned electron transporting mixed layer. That is, as shown in FIG. 3, the proportion of the electron injecting material is increased toward the cathode, and the proportion of the electron transporting material is increased as it is moved away from the cathode. Due to the formation of this concentration gradient, electrons are smoothly received from the cathode side and transported without generating a large energy barrier, contributing to the reduction of the driving voltage and the extension of the service life.
[75] There is also a method of mitigating an energy barrier to the light emitting layer. That is, the light emitting layer can be provided as a bipolar layer (called a "bipolar-characteristic mixed layer"), which is obtained by mixing together a high hole mobility hole transport material and a high electron mobility material. In this case, the light emitting layer reduces the carrier blocking function of the interface at both ends, but the number of recombination of carriers is increased due to the difference in mobility between the electron transport layer and the bipolar-mixed layer and between the hole transport layer and the bipolar-mixed layer. .
[76] It is also desirable to form concentration gradients in the bipolar-characteristic mixed layer described above. That is, as shown in FIG. 4, the proportion of hole transport material is increased toward the anode, and the proportion of electron transport material is increased toward the cathode. Due to the formation of such concentration gradients, the steps from the transport of holes and electrons to recombination are performed smoothly without creating a large energy barrier, which contributes to lowering the driving voltage and extending service life.
[77] In addition, in bipolar-characteristic mixed layers, it is believed that materials with low excitation energy emit more light. The excitation energy described in the specification of this application represents the energy difference between HOMO and LUMO. HOMO can be measured via photoelectron spectroscopy and is thought to be equal to the ionization potential. Also, for convenience, defining the excitation energy at the end of the absorption spectrum, it is possible to calculate LUMO from the values of the excitation energy and the HOMO level.
[78] There is also a method of doping a luminescent material in the bipolar-characteristic mixed layer for luminescence. In this case, the dopant luminescent material should have lower excitation energy than the electron transport material and hole transport material contained in the bipolar-characteristic mixed layer. Preferably, it is preferable to use a carrier trap type dopant (rubrene) to further increase the recombination efficiency of the carrier.
[79] In addition, the hole blocking layer described in Reference 2 is generally composed of a blocking material. The blocking material generally has a greater excitation energy than the luminescent material (i.e. can prevent the diffusion of molecular excitation) and the carrier is a blocking material. In many cases, holes are blocked.
[80] The inventors of the present application devised a method of forming a layer (hereinafter referred to as a "jersey-characteristic mixed layer") obtained by mixing a material of the light emitting layer (or a host material of the light emitting layer) with a blocking material. In this case, the blocking-property mixed layer can also be regarded as a light emitting layer that can effectively block carriers and molecular excitons because it can act as a light emitting layer.
[81] In particular, the resistant-characterized mixed layer is preferably shaped with a concentration gradient. This is because the carrier of one of the unblocked layers (electron in the case of the hole blocking material) can be moved smoothly by gradually increasing the concentration of the blocking material as it moves away from the light emitting layer.
[82] Recently, an organic light emitting device capable of converting energy discharged from the triple excited state to the ground state (hereinafter referred to as "triple excitation energy") to luminance has been successfully presented, and luminescent efficiency has attracted attention. 7: DF O'Brien, MA Baldo, ME Thompson, and SR Forrest, "Improved energy transfer in electrophosphorescent device", Applied Physics Letters, vol. 74, no. 3, 442- 444 (1999)) (Note 8: Tetsuo TSUTSUI, Moon-Jae YANG, Masayuki YAHIRO, Kenji NAKAMURA, Teruichi WATANABE, Taishi TSUJI, Yoshinori FUKUDA, Takeo WAKIMOTO, and Satoshi MUYAGUCHI, High Quantum Efficiency in Organic Light-Emitting Devices with Iridium-Complex as a Triplet Emissive Center ", Japanese Journal of Applied Physics, vol. 38, L1502-L1504 (1999).
[83] In reference 7, a metal complex with platinum is used, and in reference 8 a metal complex with iridium is used as the central metal. These organic light emitting devices (hereinafter referred to as "triple light emitting diodes") capable of converting triple excitation energy into luminescence can shine with higher brightness and higher luminous efficiency than conventional ones.
[84] However, according to the report of Reference 8, when the initial luminance is set to 500 cd / m ² , the half life of the luminance is about 170 hours, which is not a satisfactory device life. Here, applying the present invention to a triple light emitting diode can provide a highly functional light emitting device, which extends its life in addition to high intensity luminance and high luminous efficiency based on the luminance from the triple excited state.
[85] Thus, the present invention covers the application of the concept to triple light emitting diodes, whereby the carrier transport layer and the light emitting layer smooth the movement of the carrier by causing the mixed layer to reduce the number of interfaces (or to mitigate energy barriers).
[86] In addition, the inventor of the present application considers the following two mechanisms as one model, in which the movement of the carrier is hindered by the formation of the organic interface.
[87] First, one mechanism is believed to arise from the form of an organism interface. The organic compound layer of the organic light emitting device is generally composed of a film in an amorphous state, so that molecules of the organic compound are collected by intermolecular forces mainly based on dipole-dipole interactions. However, when such molecular collection is used to form a heterostructure (laminated structure), the interface of the heterostructure (ie, the organic interface) is likely to be greatly affected by the difference in molecular size and molecular composition.
[88] In particular, when materials with many different molecular sizes are used to form heterostructures, it is believed that the conjugation at the organic interface is not well aligned. The concept is shown in FIG. In FIG. 21, a first layer 2111 composed of small molecules 2101 and a second layer 2112 composed of large molecules 2102 are stacked together. In this case, poorly aligned regions 2114 are created over the formed organic interface 2113.
[89] Since the poorly aligned region 2114 shown in FIG. 21 is likely to create a barrier (or energy barrier) that impedes the movement of the carrier, it is proposed to create an obstacle to further reducing the drive voltage. In addition, carriers that cannot cross the energy barrier can accumulate in charge, leading to the above-mentioned reduction in light emission.
[90] Another mechanism is believed to occur in the process of forming the laminated structure (ie, the organic interface). In terms of carrier blocking and functional separation, organic light emitting devices in a laminated structure are generally multi-chambered (in-line) as shown in FIG. 22 to prevent contamination in the formation of each layer. It is made using a deposition apparatus.
[91] 22 is a conceptual diagram showing an example of a deposition apparatus for forming a three-layer structure (double hetero structure) composed of a hole transporting layer, a light emitting layer, and an electron transporting layer. First, a substrate including an anode (eg, indium tin oxide (ITO)) is transferred to an internal transport chamber, and ultraviolet light is irradiated from the ultraviolet radiation chamber into a vacuum atmosphere to clean the surface of the anode. In particular, when the anode is an oxide such as ITO, oxidation treatment is performed in the pretreatment chamber. Further, in order to form the layers of the laminated structure, a deposition process is performed in the deposition chamber 2201 in the hole transport layer, and the light emitting layer (three colors including the red, green, and blue layers in FIG. 12) is deposited in the deposition chamber 2202. 2204, an electron transport layer is formed in the deposition chamber 2205, and a cathode is formed in the deposition chamber 2206. Finally, a suture process is performed in the suture chamber, and the substrate is externally conveyed to obtain an organic light emitting element.
[92] This in-line deposition apparatus has the property of performing deposition of each layer in different deposition chambers 2201-2205. That is, the device is configured such that mixing of the materials of the layer is almost completely prevented.
[93] Although the internal pressure of the deposition apparatus is typically reduced to about 10 ⁻⁴ to 10 ⁻⁵ pascal, there are small amounts of gaseous components (such as oxygen and water). With this degree of vacuum, it can be said that these small amounts of gas components can easily form a single molecule absorbing layer in seconds.
[94] Therefore, when the organic light emitting element of the laminated structure is manufactured using the apparatus shown in Fig. 22, a large gap between the formation of one layer and the formation of another layer becomes a problem. That is, undesirable absorbing layers (hereinafter referred to as impurity layers) due to the small amount of gaseous components can be formed, in particular, in the interval between layer formations when the substrate is transferred through the second outer transport chamber.
[95] Fig. 23 shows a conceptual diagram therefor. 23 shows that the impurity layer 2313 is formed of the first layer 2311 formed of the first organic compound 2301 and the second layer 2312 formed of the second organic compound 2302 when the second layer is laminated on the first layer. Is formed from a small amount of impurities 2303 (such as water and oxygen) in between.
[96] An impurity layer is formed between the layers (i.e., the organic interface) in this method, and acts as an impurity region that traps the carrier after the organic light emitting element is completed, thereby preventing the carrier from moving and raising the driving voltage. . Furthermore, the presence of the impurity region trapping the carrier causes charge to accumulate, so that the above-described decrease in brightness can be induced.
[97] In view of this mechanism, in order to overcome the above-mentioned problems (deterioration of the shape of the organic interface and the formation of the impurity layer), the device structure and the fabrication process are both required to be free from the device of the conventional laminated structure. do. As an example of an organic light emitting device in which the organic interface is completely removed, an organic light emitting device has been reported in which only a single layer composed of a mixture of a hole transporting material and an electron transporting material (hereinafter referred to as a "single mixed layer") is provided between two electrodes ( Reference 9: Shigeki NAKA, Kazuhisa SHINNO, Hiroyuki OKADA, Hiroshi ONNAGAWA, and Kazuo MIYASHITA, "Organic Electroluminescent Devices Using a Mixed Single Layer", Japanese Journal of Applied Physics, Vol. 33, No. 12B, L1772-L1774 (1994)).
[98] In reference 9, the monolayer structure is 4,4'-bis [N- (3-methylphenyl) -N-phenyl-amino] -biphenyl (hereinafter referred to as "TPD"), which is a hole transport material, and Alq3, which is an electron transport material. It is formed by mixing the ratio of 1: 4d. However, compared to the monolayer structure of the laminated structure (ie, the heterostructure formed with the organic interface composed of TPD and Alq ₃ ), the former is described as being worse than the laminated structure in terms of luminous efficiency.
[99] The reason for this is believed that in a single mixed layer, holes filled from the anode and electrons filled from the cathode are often transferred to the opposite electrode without recombination. This problem does not occur because the laminated structure operates to block the carrier.
[100] In other words, it can be said that this is due to the fact that no functional realization occurred in the single mixed layer described in reference 9. That is, if the organic compound layer is not provided, the regions capable of realizing each function, such as the region near the anode for the hole transport operation and the region near the cathode for the electron transport operation, and the light emitting region away from the two electrodes (that is, In the region where the carrier recombines), even if the organic interface is removed, no effective light emission is given. Since the entire organic compound layer acts as a light emitting layer, there is a possibility that light is emitted near the electrode. As a result, a quench occurs in the transfer of energy to the electrode.
[101] In this way, taking into account that a single mixed layer cannot exhibit all of its functions, the inventor of the present application eliminates the organic interface when the bipolar-characteristic mixed layer shown in FIG. Unlike the present invention, a method of realizing an organic light emitting device capable of functional realization has been devised. 24 illustrates the concept described above.
[102] In FIG. 24, the organic compound layer 2403 composed of two kinds of materials including a hole transport material and an electron transport material includes a hole transport area 2405 made of an electron transport material, and an electron transport area 2406 made of an electron transport material. ), And a mixing region 2407 in which the hole transporting material and the electron transporting material are mixed together. When the anode 2402 is provided on the substrate 2401, an inverse structure is adopted so that the cathode 2404 can be provided on the substrate. In addition, with such a device, a defined layer structure such as a hole transport layer is not formed, and " regions " representing respective functions are used.
[103] When such an element is formed, the hole transport material receives and transports holes on the anode side, and the electron transport material receives and transports electrons on the cathode side. First, since the mixed region 2407 is bipolar-characteristic, both holes and electrons can be moved in the mixed layer 2407, and the carrier is recombined in the mixed region 2407 for light emission. That is, unlike the single mixed layer described in Reference 9, the organic compound layer 2403 is given a region that can exhibit each function.
[104] In addition, although the functional realization is possible with the device shown in Fig. 24, the organic interface is not given in the conventional laminated structure. In addition, the quenches can be prevented by separating the light emitting region as far as possible from the two electrodes. Therefore, the problems (deterioration of the shape of the organic interface and the formation of the impurity layer) generated in the above-described organic interface can be solved.
[105] First, a description will be given with reference to FIG. 25 to solve the deterioration of the shape of the organic interface. FIG. 25 illustrates a region 2511 typical of FIG. 24 and composed of small molecules 2501, a region 2512 composed of large molecules 2502, and a mixed region comprising both small molecules 2501 and large molecules 2502. An organic light emitting element having a 2513 is shown. As is apparent from FIG. 25, not only the organic interface 2113 shown in FIG. 21, but also the poor alignment region 2114 is not given.
[106] In addition, the method of solving the formation of the impurity layer is simple and clear. When fabricating the organic light emitting device shown in Fig. 24, the hole transport material is deposited on the anode, and the electron transport material is additionally deposited in the form of a code position to form a mixed layer, and after formation of the mixed region, Deposition of the transport material may be stopped to allow deposition of the electron transport material. Thus, no spacing is generated when using the deposition apparatus shown in FIG. 22 to fabricate an organic light emitting element. That is, there is no opportunity to form an impurity layer.
[107] In this way, the organic light emitting element according to the present invention is free from the formation of the organic interface, so that the movement of the carrier is smooth and does not adversely affect the lifetime of the element and the driving voltage. In addition, there is no problem in luminous efficiency even if functional separation is included, such as a laminated structure.
[108] In addition, the conventional laminated structure has a simple hetero-junction between different materials, and the structure according to the present invention can be referred to as a mixed-junction and can be referred to as an organic light emitting device based on a new concept.
[109] Accordingly, the present invention provides a light emitting device having an anode, a cathode, and an organic light emitting device having an organic compound layer provided between the anode and the cathode, wherein the organic compound layer has a hole transport material having higher hole mobility than electron mobility. A hole transport region consisting of an electron transport region composed of an electron transport material having higher electron mobility than hole mobility (the hole transport region is disposed closer to the anode than the electron transport region), and between the hole transport region and the electron transport region, And a mixing zone containing both the hole transport material and the electron transport material.
[110] In addition, with the structure shown in FIG. 24, a hole injection region composed of a material (hereinafter referred to as " hole injection material ") that enhances the carrier filling property of the hole is inserted between the anode and the organic compound layer. In addition, an electron injection region composed of a material (hereinafter referred to as an "electron injection material") that enhances the charging properties of the electrons is inserted between the cathode and the organic compound layer. In addition, both the hole injection region and the electron injection region may be inserted.
[111] In this case, since the hole injection material and the electron injection material are materials for reducing the carrier filling barrier from the electrode to the organic compound layer, it is effective to smooth the movement of the carrier from the electrode to the organic compound layer, thereby eliminating the accumulation of charge. However, for the purpose of preventing the formation of the impurity layer described above, it is preferable to carry out the deposition without a gap between each filler material and the organic compound layer.
[112] Here, in terms of carrier balance, it is desirable to form a concentration gradient in the mixed region including both the hole transport material and the electron transport material, so that the concentration of the hole transport material gradually decreases from the anode to the cathode and the electron transport material gradually increases. . In the present invention, since the mixed region becomes a carrier recombination region, it is preferable to have a thickness of 10 nm or more.
[113] In addition, the present invention further provides the present invention is characterized in that the organic compound layer 2603 includes a hole transport region 2605 composed of a hole transport material, an electron transport region 2606 composed of an electron transport material, and a hole transport material and an electron transport. A mixed region 2607 in which the materials are mixed together, and a light emitting material 2608 for luminance is added to the mixed region 2607 as a dopant. In addition, an anode is provided to the substrate 2601, but an inverse structure is adopted so that the cathode 2604 can be provided to the substrate. In addition, a hole injection region and an electron injection region may be provided between the electrode and the organic compound layer.
[114] When the luminescent material 2608 is added to the mixed region 2607, the luminescent material 2608 traps the carrier, so that recombination efficiency is enhanced and high luminous efficiency can be expected. One of the particulars is that the luminescent color can be controlled by the luminescent material 2608. However, in this case, it is preferable that the excitation energy is the smallest among the compounds in which the luminescent material 2608 is included in the mixed region 2607.
[115] In addition, the quench that occurs upon energy transfer to the electrode material can be prevented by separating the light emitting regions as far as possible from the two electrodes. Thus, the region to which the luminescent material is doped may be a part (particularly, the central portion) of the mixed region, not the whole.
[116] In addition, the present invention provides a hole transport region 2605 in which the organic compound layer 2603 is made of a hole transport material, an electron transport region 2606 made of an electron transport material, and a hole transport material and an electron transport as shown in FIG. 26B. A mixed region 2607 in which the materials are mixed together, and a resistant material 2609 is added to the mixed region 2607. In addition, an anode 2602 is provided on the substrate 2601, but an inverse structure is adopted so that the cathode 2604 can be provided on the substrate. In addition, a hole injection region and an electron injection region may be provided between the electrode and the organic compound layer.
[117] When the blocking material 2609 is added to the mixed region 2607, the carrier recombination efficiency of the mixed region 2607 is enhanced and dispersion of molecular excitons can be prevented, so high luminous efficiency can be expected. In this case, however, it is preferable that the blocking material be the maximum at the excitation energy level among the materials included in the mixing region 2608.
[118] In addition, in many cases the blocking material operates to block one of the holes and electrons, sometimes breaking the carrier balance in the mixing zone when doped across the entire mixing zone. Thus, the region doped with the blocking material may be part (particularly the end) rather than the entire region of the mixed region.
[119] In addition, as a more preferred example of FIG. 26B, a luminescent material 2608 is added. That is, this configuration has the combination of Fig. 26A. In the case where the blocking material 2609 is hole blocking property, the light emitting material 2608 is effectively added by adding the hole blocking material to the side closer to the cathode than the region to which the light emitting material 2608 is added, as shown in FIG. 26B. Let it glow.
[120] Furthermore, the application of the present invention to a triple light emitting diode provides a high functional light emitting device, and in addition to the high intensity luminance and high luminous efficiency based on the luminance from the triple excited state, the service life is compared with that described in Reference 8 Is extended.
[121] In addition, since the triple molecular exciton is larger in diffusion distance than the single molecule excitons, it is preferable that the blocking block is included in the mixed region. That is, referring to FIG. 26B, it is preferable that a material capable of converting triple excitation energy into luminance (hereinafter referred to as "triple light emitting material") is used as the light emitting material 2608 and the blocking material 2609 is added at the same time. .
[122] Next, an example suitable for fabrication in a structure including the addition of a luminescent material as shown in FIGS. 26A and 26B is described. 27 shows such a device structure.
[123] In the device shown in FIG. 27, a hole transport region 2705 composed of a hole transport material, an electron transport region 2706 composed of an electron transport material, and a hole are formed in an organic compound layer 2703 including a hole transport material and an electron transport material. A mixed region 2707 is provided in which a transport material and an electron transport material are mixed together in a specific ratio, and a light emitting material 2708 for luminance is added to the mixed region 2707 to form a light emitting region. An anode 2702 is provided to the substrate 2701, but an inverse structure is adopted so that the cathode 2704 can be provided to the substrate.
[124] In addition, FIG. 28 shows the concentration profile when the concentration ratio of the hole transporting material and the electron transporting material in the mixed region is x: y.
[125] When such an element is formed, the hole transport material may receive and transport holes on the anode side, and the electron transport material may receive and transport electrons on the cathode side. In addition, since the mixed region 2707 is bipolar-characteristic, both holes and electrons can move in the mixed region 2707. In addition, due to the specific ratio x: y in the mixed region 2707, fabrication is easy.
[126] Here, the light emitting region including the light emitting material is basically formed in the mixed region 2707. That is, adding the luminescent material to the mixed region 2707 keeps the luminescent region away from the electrode to prevent the carrier from passing through the mixed region without recombination and at the same time prevent the quench generated by the electrons.
[127] Accordingly, the present invention provides a light emitting device having an anode, a cathode, and an organic light emitting element having an organic compound layer provided between the anode and the cathode, wherein the organic compound layer comprises a hole transport region, an electron An electron transport zone comprised of the transport material, provided between the hole transport zone and the electron transport zone, and having a mixing zone comprising the hole transport material and the electron transport material at a specific ratio, provided to the mixing zone and the luminous material to emit light The presented light emitting area is added.
[128] In addition, the light emitting material preferably has a lower excitation energy as compared to the hole transporting material and the electron transporting material. This aims to prevent energy transfer in the molecular excitons.
[129] Also, in the structure shown in FIG. 27, a hole injection region composed of a material (hereinafter referred to as "hole injection material") for enhancing the filling property of the hole can be inserted between the anode and the organic compound layer. In addition, an electron injection region composed of a material (hereinafter referred to as an "electron injection material") for enhancing the charging property of electrons may be inserted between the cathode and the organic compound layer. In addition, both the hole injection region and the electron injection region may be inserted.
[130] In this case, since the hole injection material or the electron injection material is a material for reducing the carrier charge barrier from the electrode to the organic compound layer, it is effective to smooth the carrier movement from the electrode to the organic compound layer to eliminate charge accumulation. However, for the purpose of preventing the formation of the impurity layer described above, it is preferable to perform deposition without a gap between each filler material and the organic compound layer.
[131] In addition, the portion for carrier recombination (substantially centered since it is bipolar-characteristic) is determined in the mixing region substantially depending on the mixing ratio. Thus, the luminescent material is added over the entire mixed region (FIG. 29A), but may be added to a portion of the mixed region (FIG. 29B). In addition, reference numerals of FIG. 27 are referred to in FIGS. 29A and 29B.
[132] In addition, the present invention provides a hole transport region 2705 in which the organic compound layer 2703 is made of a hole transport material, an electron transport region 2706 made of an electron transport material, and a hole transport material and electron transport as shown in FIG. 30A. Providing a mixed region 2707 in which the materials are mixed together, a luminescent material added, and a blocking material 2709 added to the mixed region 2707. In addition, an anode 2702 is provided to the substrate 2701, but an inverse structure is adopted so that the cathode 2704 can be provided to the substrate. In addition, the hole injection region and the electron injection region may be provided between the electrode and the organic compound layer.
[133] In this case, the blocking material preferably has the highest excitation energy level among the materials included in the mixing region 2707 and has a function of blocking carriers or preventing diffusion of molecular excitons. When the blocking material 2709 is added to the mixing region 2707, the recombination efficiency of the carrier in the mixing region 2707 can be enhanced and diffusion of molecular excitons can be prevented, so high luminous efficiency can be expected. In many cases, however, the blocking material operates to block one of the holes and electrons, sometimes breaking the carrier balance in the mixing zone when added to the entire mixing zone. Thus, the region to which the block material is added becomes part of the mixed region, not the entire region of the mixed region.
[134] In addition, what is typically effective as a blocking material is a material having a low HOMO level, that is, capable of blocking holes. Thus, as shown in FIG. 30B, a method of adding a blocking material to the cathode side rather than a region to which the luminescent material 2708 is added is useful.
[135] In addition, the application of the triple luminescent material as a luminescent material added to such an element structure provides a highly functional light emitting device, which provides service in addition to high intensity luminance and high luminous efficiency based on luminescence from the triple excited state. Life is extended. In addition, since the triple molecule excitons have a larger diffusion length compared to the single molecule excitons, it is preferable that the blocking material is included in the mixed region.
[136] Here, the mixing region composed of the hole transporting material and the electron transporting material is required to be bipolar-characteristic, so that the ratio of the mass of the hole transporting material to the total mass of the hole transporting material and the electron transporting material in the mixing area is 10% or more and It is preferable that it is 90% or less. However, it is believed that the ratio varies greatly depending on the combination of materials.
[137] In addition, since the mixed region composed of the hole transporting material and the electron transporting material includes a light emitting area, that is, a carrier recombination area, it is required to have some thickness so that carrier transfer is not allowed. Therefore, it is preferable that the mixed region has a thickness of 10 nm or more. Further, in consideration of the fact that the region to be bipolar-characteristic has a high resistance, the thickness is preferably 100 nm or less.
[138] By implementing the above-described invention, a light emitting device having a lower driving voltage and a longer service life than the conventional one can be provided. In addition, when manufactured using such a light emitting device, an electronic product having a lower power consumption and longer lasting than the prior art can be provided.
[1] 1A and 1B show the role of a hole injection layer.
[2] 2 shows a concentration gradient.
[3] 3 shows a concentration gradient.
[4] 4 shows a concentration gradient.
[5] 5 shows the structure of an organic light emitting element;
[6] 6 is a diagram showing the structure of an organic light emitting element.
[7] 7 illustrates the structure of an organic light emitting element.
[8] 8 illustrates the structure of an organic light emitting element.
[9] 9 is a diagram showing the structure of an organic light emitting element.
[10] 10 is a diagram showing the structure of an organic light emitting element.
[11] 11 shows a deposition apparatus.
[12] 12A and 12B show a cross-sectional structure of a light emitting device.
[13] 13A and 13B show a top surface structure and a cross-sectional structure of a light emitting device.
[14] 14A to 14C show a top surface structure and a cross-sectional structure of the light emitting device.
[15] 15A and 15B show the structure of a light emitting device.
[16] 16A and 16B show the structure of a light emitting device.
[17] 17A to 17F are diagrams showing specific examples of electronic products.
[18] 18A and 18B are diagrams showing specific examples of electronic products.
[19] 19A and 19B show an energy band diagram.
[20] 20A and 20B show an energy band diagram.
[21] 21 shows a state of the organic compound layer.
[22] 22 shows a deposition apparatus.
[23] Fig. 23 shows the formation of an impurity layer.
[24] Fig. 24 is a diagram showing the structure of an organic light emitting element.
[25] 25 shows a state of an organic compound layer.
[26] 26A and 26B show the structure of an organic light emitting element.
[27] 27 shows a structure of an organic light emitting element.
[28] 28 shows a concentration profile.
[29] 29A and 29B show the structure of an organic light emitting element.
[30] 30A and 30B show the structure of an organic light emitting element.
[31] 31A and 31B show a deposition apparatus.
[32] 32A and 32B show a deposition apparatus.
[33] 33 is a diagram showing the structure of an organic light emitting element.
[34] 34 illustrates a cross-sectional structure of a light emitting device.
[35] 35 illustrates a cross-sectional structure of a light emitting device.
[36] 36A to 36C show a cross-sectional structure of a light emitting device.
[37] 37 shows a circuit structure.
[139] Hereinafter, embodiments of the present invention will be described. In addition, an embodiment is described in which at least one of the anode and the cathode is transparent to emit light sufficiently in the organic light emitting device, and a transparent anode is formed on the substrate and light is taken from the anode for the device structure. In practice, a structure in which light is taken from the cathode and a structure in which light is taken from the opposite side of the substrate can be applied.
[140] First, an embodiment of an organic light emitting device formed with a hole transporting mixed layer will be described with reference to FIG. 5. 5 shows a structure in which the hole transporting mixed layer 503, the light emitting layer 504, the electron transporting layer 505, and the cathode 506 are stacked on a substrate 501 having an anode 502. In addition, the light emitting layer 504 is not inserted, and the hole transporting mixed layer 503 or the electron transporting mixed layer 505 can take the light emission charge. The hole transport mixing layer 503 is formed by mixing both the hole injection material and the hole transport material.
[141] In addition, as shown in FIG. 2, a hole transport mixing layer 503 is formed with a concentration gradient, which is composed of a hole injection material and a hole transport material. In this case, when an insulating material such as aluminum oxide is used as the hole injecting material, it is preferable that the hole injecting material has a steep concentration gradient (quickly decreasing to the anode side).
[142] Next, with reference to FIG. 6, an embodiment of an organic light emitting device formed with an electron transporting mixed layer will be described. In FIG. 6, the hole transport layer 603, the light emitting layer 604, the electron transport mixed layer 605, and the cathode 606 are stacked on the substrate 601 having the anode 602. In addition, the light emitting layer 604 is not inserted, and the electron transporting mixed layer 605 or the hole transporting layer 603 can take the light emission charge. The electron transporting mixed layer 605 is formed of a mixture of both the electron injection material and the electron transporting material.
[143] In addition, as shown in FIG. 3, an electron transporting mixed layer 605 is formed with a concentration gradient, which is composed of an electron injection material and an electron transport material. In this case, when an insulating material such as lithium fluoride is used as the electron injecting material, it is preferable that the electron injecting material has a steep concentration gradient (which is rapidly reduced to the anode side).
[144] Next, referring to FIG. 7, an embodiment of an organic light emitting device formed with a bipolar-characteristic mixed layer will be described. In FIG. 7, a structure in which a hole injection layer 703, a bipolar-characteristic mixing layer 704, an electron injection layer 705, and a cathode 706 are stacked on a substrate 701 having an anode 702 is illustrated. The bipolar-characteristic mixed layer 704 is formed by mixing both the hole transport material and the electron transport material.
[145] In addition, as shown in FIG. 4, a bipolar-characteristic mixed layer 704 is formed with a concentration gradient, which is composed of a hole transport material and an electron transport material.
[146] In addition, as shown in FIG. 24, the mixing region 2407, the hole conveying region 2405, and the electron conveying region 2406 are formed of the hole conveying region 2405 in the hole conveying material included in the mixing region 2407. Using the constituent material, it can be continuously coupled to the electron transport material contained in the mixed region 2407 using the constituent material of the electron transport region 2406. In this case, there are advantages that two kinds of components (hole transport material and electron transport material) can operate in three layers in the prior art having a hole transport area, a light emitting area, and an electron transport area. In addition, although not shown in FIG. 24, a hole injection layer may be inserted between the anode 2402 and the hole transport region 2405, and an electron injection layer may be inserted between the cathode 2404 and the electron transport layer 2406. Can be.
[147] This device structure is realized to prevent the formation of the impurity layer. In this case, the process of manufacturing an organic light emitting element is important. Here, an example suitable for the method of manufacturing such an element structure is described.
[148] 31A and 31B are conceptual diagrams showing deposition apparatus. Fig. 31A is a top view of the device. The deposition apparatus is of a single chamber type, in which one vacuum tank 3110 is installed into the deposition chamber and a plurality of deposition sources are provided in the vacuum tube. In many deposition sources, different materials of different functions are received separately, such as hole injection materials, hole transport materials, electron transport materials, electron injection materials, blocking materials, luminescent materials, and cathode materials.
[149] In a deposition apparatus having a deposition chamber, a substrate containing an anode (ITO, etc.) is first transported to a transport chamber, and if the anode is an oxide such as ITO, an oxidation treatment is performed in the pretreatment chamber (in addition, although in FIG. 31A Although not shown, it is possible to install an ultraviolet radiation chamber for cleaning the anode surface). Further, all materials forming the organic light emitting element are deposited in the vacuum chamber 3110. However, a cathode may be formed in the vacuum chamber 3110, or a separate deposition chamber may be provided for cathode formation. Briefly, it is sufficient that the deposition be performed in a single vacuum chamber 3110 until the cathode is formed. Finally, sealing is performed in the sealing chamber, and an organic light emitting device is obtained after the substrate is taken out of the transport chamber.
[150] A process for fabricating an organic light emitting device according to the present invention using such a single chamber deposition apparatus is described with reference to FIG. 31B (cross section of the vacuum chamber 3110). To simplify the description, FIG. 31B shows the hole transport material 3116 and electron transport using a vacuum chamber 3110 having two deposition sources (organic compound deposition source a 3118 and organic compound deposition source b 3119). The process of forming an organic compound layer composed of material 3117 is shown.
[151] First, a substrate 3101 with an anode 3102 is given to a vacuum chamber 3110 and fixed by a fixed base 3111 (generally, the substrate is rotated during deposition). Subsequently, after the pressure in the vacuum chamber 3110 is reduced (preferably 10 ⁻⁴ Pa or less), conduit a 3112 is heated to evaporate the hole transport material 3116 and to a predetermined evaporation rate in [nm] / s]), shutter a 3114 is opened to start deposition. At this time, conduit b 3113 is heated while shutter b 3115 is closed.
[152] Then, when shutter a 3114 is opened, shutter b 3115 is code localized to hole transport material 3117 (state shown in FIG. 31B) and forms mixed region 3104 behind hole transport region 3103. Open to allow. This operation eliminates the mixing of impurities between the hole transport region 3103 and the mixing region 3104.
[153] Also, to form the electron transport region, when shutter b 3115 is opened, shutter a 3114 is closed to terminate heating of conduit a 3112. This operation eliminates the formation of the impurity layer between the mixed region 3104 and the electron transport region.
[154] There is also a method of doping the luminescent material in the mixed region 2607 shown in FIG. 26A to achieve the same luminescence. In this case, it is required that the dopant luminescent material has lower excitation energy than the hole transporting material and electron transporting material contained in the mixed region 2607.
[155] In the case where the luminescent material is doped, the process of manufacturing the organic light emitting element is important for preventing the formation of impurities. The manufacturing process will be described later.
[156] 32A is a top view showing a deposition chamber of a single chamber type, in which a vacuum chamber 3210 is installed as a deposition chamber, and a plurality of deposition sources are provided in the vacuum chamber. In addition, a plurality of deposition sources are separately received with various materials of different functions, such as hole injection materials, hole transport materials, electron transport materials, electron injection materials, blocking materials, luminescent materials, and components of the cathode.
[157] In a deposition apparatus having such a deposition chamber, a substrate including an anode (ITO, etc.) is first transported to a transport chamber, and if the anode is an oxide such as ITO, an oxidation treatment is performed in the pretreatment chamber (in addition, although FIG. 32A Although not shown, it is possible to install an ultraviolet radiation chamber for cleaning the anode surface). In addition, all materials forming the organic light emitting device are deposited in the vacuum chamber 3210. However, a cathode may be formed in the vacuum chamber 3210 or a separate deposition chamber may be provided for cathode formation. Briefly, it is sufficient that the deposition be performed in a single vacuum chamber 3210 until the cathode is formed. Finally, sealing is performed in the sealing chamber, and an organic light emitting device is obtained after the substrate is taken out of the transport chamber.
[158] A process for fabricating an organic light emitting device in accordance with the present invention using such a single chamber deposition apparatus is described with reference to FIG. 32B (cross section of vacuum chamber 3210). To simplify the description, FIG. 32B uses a vacuum chamber 3210 having three deposition sources (organic compound deposition source a 3216, organic compound deposition source b 3217, and organic compound deposition source c 3218). Showing a process for forming an organic compound layer composed of a hole transport material 3221, an electron transport material 3222, and a light emitting material 3223.
[159] First, a substrate 3201 with an anode 3202 is given to a vacuum chamber 3210 and fixed by a fixed base 3211 (generally, the substrate is rotated during deposition). Subsequently, after the pressure in the vacuum chamber 3210 is reduced (preferably 10 ⁻⁴ Pa or less), conduit a 3112 is heated to evaporate the hole transport material 3221 and a predetermined evaporation rate (unit: [nm) / s]), shutter a 3214 opens and starts deposition. At this time, conduit b 3213 is also heated while shutter b 3215 is closed.
[160] Then, when shutter a 3214 is opened, shutter b 3215 is opened to allow code positioning on electron transport material 3222 to form mixing region 3204 behind hole transport region 3203. This operation eliminates the mixing of impurities between the hole transport region 3203 and the mixed region 3204. Here a very small amount of luminescent material 3223 is added during the formation of the mixed region 3204 (state shown in FIG. 32B).
[161] Further, to form the electron transport region, when shutter b 3215 is opened, shutter a 3214 is closed to terminate heating of conduit a 3212. This operation eliminates the formation of an impurity layer between the mixed region 3204 and the electron transport region.
[162] Applying this process, it becomes possible to fabricate all the organic light emitting elements described above for the solution to the problem. For example, when adding a blocking material to the mixing region 3204, it is sufficient to evaporate it in the process of installing the deposition source and forming the mixing region for the deposition of the blocking material as shown in FIG. 32B.
[163] In addition, when forming a hole injection region or an electron injection region, it is sufficient to install a deposition source in the same vacuum conduit 3210 for each fill material. For example, in FIG. 32B, when providing a hole injection region by deposition between the anode 3202 and the hole transport region 3203, the formation of the impurity layer is spaced from the point where the hole injection material is deposited on the anode 3202. Can be avoided by evaporating the hole transport material 3221.
[164] In addition, since the concentration gradient can be formed in the above-described mixing region, an exemplary method of forming the concentration gradient is referred to. Here, the case where the deposition can be made by vacuum deposition due to resistive heating is described. For the method of forming the concentration gradient, it is possible to control the deposition rate by temperature control when a correlation is established between the evaporation temperature of the material and the deposition rate (typically in units of nm / s). However, organic materials, especially used in the form of particles, are generally poor in terms of thermal conductivity and, therefore, are prone to nonuniformity when controlled by temperature. Therefore, it is desirable to prepare two kinds of materials for the formation of concentration gradients in separate deposition sources and to control the deposition rate using a shutter (film thickness is monitored by a crystal oscillator). This configuration is shown in FIG.
[165] In FIG. 11, a method of forming the concentration gradient through the device structure illustrated in FIG. 24 is described. Therefore, reference numerals used in FIG. 24 are referred to in FIG. 11. First, a substrate 1101 with an anode 1102 is transported to the film formation chamber 1110 and fixed to the fixed base 1111 (the substrate is generally rotated during deposition).
[166] Subsequently, sample chamber a 1112 receiving the hole transport material 1116 is heated, and shutter a 1114 is opened to cause deposition of the hole transport area 2405 comprised of the hole transport material 1116. At this time, the sample chamber b 1113 receiving the electron transport material 1117 is also simultaneously heated while the shutter b 1115 is closed.
[167] When the hole transport area 2405 reaches a predetermined film thickness, the shutter a 1114 is gradually closed, and at the same time the shutter b 1115 is gradually opened. At this time, the opening and closing speed forms the concentration gradient with respect to the mixed region 2407. The opening / closing speed is reached when the mixing area 2407 reaches a predetermined film thickness and the electron transporting material 1117 reaches a predetermined deposition rate (ratio upon deposition of the electron transporting area 2406) when the shutter a 1114 is completely closed. It can be set to. Subsequently, while the shutter b 1115 is open, the electron transport region 2406 is formed, so that the element formed with the concentration gradient in the element structure shown in FIG. 24 becomes possible.
[168] In addition, this method is applicable to all cases of forming concentration gradients in device structures other than those shown in FIG. In addition, when a luminescent material is added to the bipolar-characteristic mixed layer or mixed region, it is sufficient to increase one or more deposition sources in FIG. 11 and open the shutter for the dopant deposition source only during the doping time period.
[169] However, the method of forming the concentration gradient is not limited to the above method.
[170] Here, some embodiments described above can be used in combination. For example, a hole transporting mixed layer, an electron transporting mixed layer, and a bipolar-characteristic mixed layer are applied in combination. An example thereof is shown in FIG. 8.
[171] In the device structure shown in FIG. 8, the hole transporting mixed layer 803, the hole transporting material 812, and the electron transporting of the hole injection material 811 and the hole transporting material 812 on the substrate 801 having the anode 802. A bipolar-characteristic mixed layer 804 composed of a material 813, an electron transport mixed layer 805 composed of an electron transporting material 813 and an electron injection material 814, and a cathode 806 are stacked.
[172] In addition, in this embodiment, a light emitting region 807 doped with a small amount of light emitting material 815 is provided in the bipolar-characteristic mixing layer 804. In addition, the concentration gradient shown in graph 810 was formed in each layer. In addition, FIG. 19B is a diagram showing a band diagram expected when such a concentration gradient is formed.
[173] In the device structure, the three-layer structure (Fig. 19B) includes a four-layer structure (Fig. 19A) composed of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer in the prior art. In addition, as shown in FIG. 19B, each mixed layer is given only a gentle energy barrier, and each mixed layer is continuously connected by the hole transporting material 812 and the electron transporting material 813, and thus the carrier movement. It is advantageous to
[174] Next, an embodiment in the case where an element in which each mixed layer is combined in the above manner is applied to a triple light emitting diode is described. Generally, the basic structure of a triple light emitting diode is shown in FIG. 9 as given in reference 8. That is, the structure includes a substrate 901, an anode 902, a hole transport layer 903, a light emitting layer 904, a stop layer 905, an electron transport layer 906 formed by doping a triple light emitting material from a host material, And a cathode 907. The blocking layer 905 is made of a blocking material and blocks holes to act to enhance the recombination efficiency of carriers in the light emitting layer 904 and to prevent scattering molecular excitons generated in the light emitting layer 904. The layer is also a material for the transport of electrons.
[175] In the device structure shown in Fig. 9, the luminous efficiency can be further enhanced by providing a hole injection layer and an electron injection layer. However, when layers are added to the five-layer structure shown in Fig. 9, the number of interfaces is increased. Here, the present invention is applied.
[176] That is, the hole transporting layer 903 of FIG. 9 is made of a hole transporting mixed layer composed of a hole injection material and a hole transporting material, and the light emitting layer 904 is made of a bipolar-characteristic mixed layer composed of a hole transporting material and a host material of the light emitting layer. A method is proposed in which the electron transport layer 906 is made of an electron transport mixed layer composed of an electron transport material and an electron injection material. The triple luminescent material may be doped at a location where the host material of the luminescent layer is given. 2 to 4, it is effective to form concentration gradients in each mixed layer.
[177] In addition, while the stop layer 905 is used in the form of a single layer in FIG. 9, it may be mixed with the host material of the light emitting layer when implementing the present invention (ie, a stop mixed layer may be formed). However, in view of preventing dispersion of molecular excitons, it is preferable to form a concentration gradient such that the blocking material has a high concentration at the cathode side.
[178] In view of the above, FIG. 10 shows an embodiment in which a device in which each mixed layer is combined is applied to a triple light emitting diode. More specifically, the substrate 1001 having the anode 1002 includes a hole transport mixed layer 1003 composed of a hole injection material 1011 and a hole transport material 1012, a hole transport material 1012, and a host material 1013. Configured bipolar-natured mixed layer 1004, resistant mixed layer 1005 composed of host material 1013 and resistant material 1014, resistant material 1014 (which in this case also acts as an electron transporting material) and electron injection material ( An electron transport mixed layer 1006 composed of 1015, and a cathode 1007 are laminated. Each layer is formed with a concentration gradient shown in graph 1010.
[179] In addition, since the present invention includes a triple light emitting diode, a light emitting region 1008 doped with a small amount of triple emitting material 1016 is provided. The light emitting region 1008 is preferably disposed in a region where the host material 1013 is of high concentration, as shown in FIG. 20B is a diagram showing a band diagram expected when the concentration gradient is formed as shown in the graph 1010.
[180] In the device structure, the four-layer structure (Fig. 20B) is a five-layer structure composed of a hole injection layer, a hole transport layer, a light emitting layer, a blocking layer (also acting as an electron transport layer), and an electron injection layer in the prior art ( 20a). In addition, as shown in FIG. 20B, each mixed layer is given only a gentle energy barrier, and each mixed layer is successively provided with a hole transport material 1012, a host material 1013, and a blocking material 1014 (also electrons). Connected continuously), which is advantageous for carrier movement.
[181] Finally, hereinafter, suitable materials are listed as constituent materials such as hole injection materials, hole transport materials, electron transport materials, electron injection materials, blocking materials, light emitting materials, and cathodes. However, the material used for the organic light emitting device of the present invention is not limited to the above.
[182] As the hole injection material, porphyrin-based compounds are effective among the organic materials, and include H 2 Pc (phthalocyanine), CuPc (copper phthalocyanine), and the like. In addition, there is a material obtained by applying chemical doping to the electroconductive polymer compound, and includes PEDOT (polyethylene dioxythiophene), PAni (polyaniline), PVK (polyvinyl carbazole) and the like doped with polystyrene sulfonic acid (PSS). In addition, the polymer compound as an insulator is effective for flattening the anode, and PI (polyimide) is often used. In addition, non-organic compounds are used and include not only ultra thin films of aluminum oxide (alumina) but also thin metal films such as gold and platinum.
[183] The most widely used materials for hole injection are aromatic amine-based compounds (ie, containing benzene ring-nitrogen bonds). Widely used materials, in addition to the TPDs described above, are derivatives thereof, namely 4,4'-bis- [N- (1-naphthyl) -N-phenyl-amino] -biphenyl (α-NPD) and 4,4 ' , 4 "-tris (N, N-diphenyl-amino) -triphenyl amine (TDATA), 4,4 ', 4" -tris [N- (3-methylphenyl) -N-phenyl-amino] -triphenyl amine (MTDATA Star burst aromatic amine compounds such as;
[184] Metal complexes are sometimes used as electron transport materials, in addition to Alq ₃ described above, tris (4-methyl-8-quinolinolate) aluminum (Al (mq ₃ )), bis (10-hydroxybenzo [h] -quinolinate) beryllium Metal complexes of a quinoline skeleton or a benzoquinoline skeleton such as (Be (Bq) ₃ ), and bis (2-methyl-8-quinolinolate)-(4-hydroxy-biphenylil) -aluminum (BAlq); Same mixed ligand complex. Among the metal complexes, oxazoles such as bis [2- (2-hydroxypheyl) -benzooxazolate] zinc (Zn (BOX) ₂ ) and bis [2- (2-hydroxypheyl) -benzothiazolate] zinc (Zn (BTZ) ₂ ) Some have oxazole-based ligands and thiazole-based ligands. In addition, in addition to the metal complex, 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (PBD), 1,3-bis [5- (p-tert- butylphenyl) -1,3,4-oxadiazole-2-il] oxadiazole derivatives such as benzene (OXD-7), 5- (4-biphenylyl) -3- (4-tert-butylphenyl) -4-phenyl- 1,2,4-triazole (TAZ), 5- (4-biphenylyl) -3- (4-tert-butylphenyl) -4- (4-ethylpheyl) -1,2,4-triazole (p-EtTAZ) and the like Such triazole derivatives, and phenanthroline derivatives such as bathophenanthroline (BPhen), bathocupuroin (BCP) and the like, and these derivatives have electron transporting properties.
[185] The electron transport material given above can be used as the electron injection material. In addition, ultra-thin films of insulators of alkali metal halides such as lithium fluoride and the like and alkali metal oxides such as lithium oxide are often used. Alkali metal complexes such as lithium acetyl acetonate (Li (acac)) and 8-quinolinolate-lithium (Liq) are also effective.
[186] As the blocking material, BAlq, OXD-7, TAZ, p-EtTAZ, BPhen, BCP and the like described above with high excitation energy levels can be used.
[187] As the light emitting material, various kinds of fluorescent dyes (including those used as dopants) may be used, and Alq ₃ , Al (mq) ₃ , Be (Bq) ₂ , BAq, Zn (BOX) ₂ , Zn (BTZ) _The above-described metal composites such as ₂ may also be used. In addition, triple luminescent materials are usable and consist mainly of a composite in which the central metal is platinum or iridium. Tri-luminescent materials include tris (2-phenylpyridine) iridium (Ir (ppy) _a ), 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-porphyrin-platinum (PtOEP) Known.
[188] By combining the above-described materials having respective functions and applying the materials to the organic light emitting device of the present invention, it is possible to fabricate an organic light emitting device having a lower driving voltage and a longer life than the conventional ones.
[189] Example 1
[190] In this embodiment, a device to which the hole transporting mixed layer shown in FIG. 5 is applied will be described in detail.
[191] First, indium tin oxide (ITO) is deposited on the glass substrate 501 to a film thickness of about 100 nm by sputtering to provide the anode 502. Subsequently, code positioning is performed at a deposition ratio of 1: 1 to CuPc, which is a hole injection material, and α-NPD, which is a hole transporting material, to form a hole transporting mixed layer 503, which has a film thickness of 50 nm.
[192] In addition, a layer obtained by doping Alq ₃ with 5 wt% of rubrene is laminated at a film thickness of 10 nm to provide a light emitting layer 504. Finally, Alq ₃ is deposited to a film thickness of 40 nm to provide an electron transport layer 505 and an Al: Li alloy (0.5 wt% in mass ratio) to a film thickness of about 150 nm to provide a cathode 506. Li) is deposited and it is possible to fabricate a yellow light organic light emitting device derived from rubin.
[193] Example 2
[194] In this embodiment, a device to which the electron transporting mixed layer shown in FIG. 6 is applied will be described in detail.
[195] First, ITO is deposited on the glass substrate 601 to a film thickness of about 100 nm by sputtering to provide the anode 602. Subsequently, α-NPD, which is a hole transporting material, is deposited to a film thickness of 50 nm to form the hole transporting layer 603.
[196] In addition, perylene is laminated to a film thickness of 10 nm to provide the light emitting layer 604, and then 1: 1 to form the electron transporting mixed layer 605 in the electron transporting material BPhen and the electron injection material Alq _3. Code localization is done at a deposition rate of, which has a film thickness of 40 nm. Finally, an Al: Li alloy (0.5 wt% Li in mass ratio) is deposited to provide a cathode 606 at a film thickness of about 150 nm to fabricate a blue light organic light emitting device derived from perylene. It is possible.
[197] Example 3
[198] In the present embodiment, an organic light emitting device obtained by inserting a hole injection region made of a hole injection material between an anode 2402 and an organic compound layer 2403 in the organic light emitting device shown in FIG. 24 will be described in detail.
[199] First, a glass substrate 2401 is prepared, and on it, ITO is deposited to a film thickness of about 100 nm by sputtering to form an anode 2402. Glass substrate 2401 with anode 2402 is conveyed to a vacuum chamber as shown in FIGS. 31A and 31B. In this embodiment, four kinds of materials (three kinds of organic compounds and one kind of metal forming a cathode) are deposited, so four deposition sources are required.
[200] First, CuPc, which is a hole injection material, is deposited at a film thickness of 20 nm, and deposition of the α-NPD, which is a hole transport material, is 0.3 nm, with no interval from the time when the film thickness is 20 nm until the deposition of CuPC is completed. starts at a deposition rate of / sec. The reason why deposition starts without such a gap is to prevent the formation of the impurity layer described above.
[201] After the hole transport layer 2405 composed only of α-NPD is formed to have a film thickness of 30 nm, the deposition of Alq ₃ , an electron transporting material, starts at a deposition rate of 0.3 nm / sec, and the deposition rate of α-NPD is It is kept fixed at 0.3 nm / sec. That is, a mixed region 2407 in which the ratio of α-NPD and Alq ₃ is 1: 1 is formed by code localization.
[202] After the mixed region 2407 reaches the film thickness of 30 nm, the deposition on the α-NPD is terminated, and only Alq ₃ is continuously deposited to form the electron transport layer 2406, which has a film thickness of 40 nm. . Finally, an Al: Li alloy is deposited to a cathode at a film thickness of about 150 nm to obtain an organic light emitting device of green light originating from Alq ₃ .
[203] Example 4
[204] In the present embodiment, an organic light emitting device obtained by inserting a hole injection region made of a hole injection material between an anode 2702 and an organic compound layer 2703 in the organic light emitting device shown in FIG. 29A will be described in detail.
[205] First, a glass substrate 2701 is prepared, on which ITO is deposited to a film thickness of about 100 nm by sputtering to form an anode 2702. Glass substrate 2701 with anode 2702 is conveyed to a vacuum chamber as shown in FIGS. 32A and 32B. In this embodiment, five kinds of materials (four kinds are organic compounds and one kind is a metal forming a cathode) are deposited, so five deposition sources are required.
[206] First, CuPc, which is a hole injection material, is deposited at a film thickness of 20 nm, and deposition of the α-NPD, which is a hole transport material, is 0.3 nm, with no interval from the time when the film thickness is 20 nm until the deposition of CuPC is completed. starts at a deposition rate of / sec. The reason why deposition starts without such a gap is to prevent the formation of the impurity layer described above.
[207] After the hole transport layer 2705 composed only of α-NPD was formed to have a film thickness of 30 nm, deposition of Alq ₃ , which is an electron transporting material, started at a deposition rate of 0.3 nm / sec, and the deposition rate of α-NPD was It is kept fixed at 0.3 nm / sec. That is, a mixed region 2707 in which the ratio of α-NPD and Alq ₃ is 1: 1 is formed by code localization. At the same time, fluorescent dye 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM) is added to the luminescent material 2708. The deposition ratio is controlled to consist of α-NPD: Alq ₃ : DCM = 50: 50: 1.
[208] After the mixed region 2707 reaches a film thickness of 30 nm, the deposition on α-NPD and DCM is terminated, and only Alq ₃ is continuously deposited to form an electron transport layer 2706, which is a 40 nm film. Has a thickness. Finally, an Al: Li alloy is deposited to the cathode at a film thickness of about 150 nm to obtain a red light organic light emitting device derived from DCM.
[209] Example 5
[210] In this embodiment, the organic light emitting device shown in FIG. 29B is described in detail.
[211] First, a glass substrate 2701 is prepared, on which ITO is deposited to a film thickness of about 100 nm by sputtering to form an anode 2702. Glass substrate 2701 with anode 2702 is carried in a vacuum conduit as shown in FIGS. 32A and 32B. In this embodiment, four kinds of materials (three kinds of organic compounds and one kind of metal forming a cathode) are deposited, so four deposition sources are required.
[212] After the hole transport layer 2705 composed only of the α-NPD, the hole transporting material, was formed to have a film thickness of 40 nm, deposition of Alq ₃ , the electron transporting material, began at a deposition rate of 0.3 nm / sec, and the α-NPD The deposition rate of was kept fixed at 0.3 nm / sec. That is, a mixed region 2707 in which the ratio of α-NPD and Alq ₃ is 1: 1 is formed by code localization.
[213] The mixed region 2707 is formed to have a film thickness of 30 nm, in which a 10 nm to 20 nm portion in the middle region of the 10 nm film thickness in the mixed region 2707 (ie, the mixed region 2707 having a 30 nm film thickness). ) Is doped with fluorescent dye 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran (DCM), which is a luminescent material 2708 at a rate of 1 wt%.
[214] After the mixed region 2707 reaches a film thickness of 30 nm, the deposition on α-NPD is terminated, and only Alq ₃ is continuously deposited to form an electron transport layer 2706, which results in a film thickness of 40 nm. Have Finally, an Al: Li alloy is deposited to the cathode at a film thickness of about 150 nm to obtain a red light organic light emitting device derived from DCM.
[215] Example 6
[216] In the present embodiment, a device obtained by adapting the concentration gradient to the device to which the mixed region shown in FIG. 26B is applied is specifically illustrated. In addition, to form the concentration gradient, the apparatus shown in FIG. 11 is used to fabricate the device. In this embodiment, three kinds of sources are required as the hole transporting material, the electron transporting material, and the luminescent material.
[217] First, ITO is deposited on the glass substrate 2601 to a film thickness of about 100 nm by sputtering to provide the anode 2602. Subsequently, the α-NPD, which is a hole transporting material, is deposited to a film thickness of 40 nm to form the hole transporting region 2605.
[218] Also, for this embodiment, the mixed region 2607 consisting of α-NPD and Alq ₃ and having a concentration gradient, simultaneously closes the shutter for the deposition source of the hole transporting material (α-NPD) and simultaneously the electron transporting material. It is deposited to a film thickness of 20 nm by gradually opening the shutter to the deposition source (Alq _{3 in} this example). In this case, the middle region of 10 nm in the mixed region 2607 having a thickness of 20 nm is doped at a rate of 5 wt% with rubin, which is a light emitting material 2608.
[219] After the mixed region reaches the film thickness 20㎚, an electron transporting region 2606 composed of Alq ₃ is formed with the shutter only for the deposition source of the electron transporting material (Alq ₃₎ is opened. Finally, an Al: Li alloy (0.5 wt% of Li at weight ratio) is deposited on the cathode 2604 at a film thickness of about 150 nm to obtain a yellow light organic light emitting device derived from rubin.
[220] Example 7
[221] In the present embodiment, in the organic light emitting device illustrated in FIG. 26B, a hole injection region made of a hole injection material is inserted between the anode 2602 and the organic compound layer 2603, and between the cathode 2604 and the organic compound layer 2603. An organic light emitting device obtained by inserting an electron injection region composed of an electron injection material is described in detail.
[222] First, a glass substrate 2601 is prepared, on which ITO is deposited to a film thickness of about 100 nm by sputtering to form an anode 2602. Glass substrate 2601 with anode 2602 is conveyed to a vacuum chamber as shown in FIGS. 31A and 31B. In this embodiment, seven kinds of materials (six kinds of organic compounds and one kind of metal forming a cathode) are deposited, so seven deposition sources are required.
[223] First, the hole injection material CuPc is deposited at a film thickness of 20 nm, and the deposition of the hole transporting material TPD is performed at a deposition rate of 0.2 nm / sec, with no interval from the time point up to 20 nm until the deposition of CuPC is completed. Begins. The reason why deposition starts without such a gap is to prevent the formation of the impurity layer described above.
[224] After the hole transport layer 2605 composed only of TPD was formed to have a film thickness of 30 nm, deposition of the electron transport material BeBq ₂ started with a deposition rate of 0.8 nm / sec, and the deposition rate of TPD was 0.2 nm / sec. It remains fixed. That is, a mixed region 2607 in which the ratio of TPD and BeBq ₂ is 1: 4 is formed by code localization.
[225] The mixed region 2607 is formed to have a film thickness of 30 nm, wherein an intermediate region of 10 nm film thickness in the mixed region 2607 (ie, 10 nm to 20 nm portion in the 30 nm mixed region 2607) is formed. It is doped with the fluorescent dye rubin, a luminescent material 2608, at a rate of 5 wt%. Further, the remaining 10 nm region (i.e., 20 nm to 30 nm portion in the 30 nm mixed region) in the mixed region 2607 is doped with the BCP, which is the blocking material 2609. The deposition rate of each material when doped with BCP is TPD: BeBq ₂ : BCP = 1: 4: 3 [nm / s].
[226] After the mixed region 2607 reaches a film thickness of 30 nm, deposition of TPD and BCP is terminated, and only BeBq ₂ is continuously deposited to form an electron transport layer 2606, which has a film thickness of 40 nm. . From the time point when the deposition of BeBq ₂ is finished, deposition of the electron injection material Li (acac) starts and begins to have a film thickness of about 2 nm. The reason why deposition starts without such a gap is to prevent the formation of the impurity layer described above.
[227] Finally, aluminum is deposited to the cathode at a film thickness of about 150 nm to obtain a yellow light organic light emitting device derived from rubin.
[228] Example 8
[229] In the present embodiment, the organic light emitting device shown in FIG. 30B is described in detail.
[230] First, a glass substrate 2701 is prepared, on which ITO is deposited to a film thickness of about 100 nm by sputtering to form an anode 2702. Glass substrate 2701 with anode 2702 is conveyed to a vacuum chamber as shown in FIGS. 32A and 32B. In this embodiment, five kinds of materials (four kinds are organic compounds and one kind is a metal forming a cathode) are deposited, so five deposition sources are required.
[231] After the hole transport layer 2705 composed solely of MTDATA, which is a hole transport material, was formed to have a film thickness of 40 nm, deposition of the electron transport material PBD started at a deposition rate of 0.3 nm / sec, and the deposition rate of MTDATA was 0.3. It is kept fixed at nm / sec. In other words, a mixed region 2707 in which the ratio of MTDATA and PBD is 1: 1 is formed by code positioning.
[232] The mixed region 2707 is formed to have a film thickness of 30 nm, in the middle region of the 10 nm film thickness in the mixed region 2707 (ie, 10 nm to 20 nm portion in the 30 nm mixed region 2707). Periline, a fluorescent dye, is added, and the deposition rate is controlled such that this addition ratio is MTDATA: PBD: periline = 4: 16: 1. Further, BCP is added as a blocking material 2709 to the last region of 10 nm in the mixed region 2707 (ie, 20 nm to 30 nm portion in the mixed region of 30 nm), and the ratio is MTDATA: PBD: BCP = 1: 4: 5.
[233] After the mixed region reaches a thickness of 30 nm, deposition of MTDATA and BCP ends, and only PBD is continuously deposited to form an electron transport layer 2706, which has a film thickness of 40 nm. Finally, an Al: Li alloy is deposited to a cathode with a film thickness of about 150 nm to obtain a blue light organic light emitting device derived from perylene.
[234] Example 9
[235] In this embodiment, a device to which the hole transporting mixed layer, dipole-characteristic mixed layer, and electron transporting mixed layer shown in FIG. In addition, in this embodiment, a deposition source having a shutter shown in FIG. 11 is used to form the concentration gradient (graph 810 of FIG. 8).
[236] First, ITO is deposited on the glass substrate 801 at about 100 nm by sputtering to form the anode 802. Subsequently, a hole transport mixed layer 803 composed of CuPc, which is a hole injection material 811, and α-NPD, which is a hole transport material 812, is deposited at 40 nm. At this time, by opening and closing the shutter, the concentration gradient as shown in the graph 810 is formed.
[237] At this time, the dipolar-characteristic mixed layer 804 having a concentration gradient gradually closes the shutter for the deposition source of α-NPD and simultaneously opens the shutter for the deposition source of Alq ₃ , which is the electron transporting material 813. Deposited at nm. At this time, the 10 nm intermediate region 807 of the 20 nm bipolar-characteristic mixed layer 804 is 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) which is a light emitting material 815 at a ratio of 1 wt%. Doped with -4H-pyran (DCM).
[238] After the bipolar-characteristic mixed layer 804 reaches a thickness of 20 nm, Alq ₃ is deposited at 35 nm with only the shutter for Alq ₃ open. Electron transport mixed layer totaling 40 nm by gradually closing the shutter for the deposition source of Alq ₃ in the last region of 5 nm and gradually opening the shutter for the deposition source of Li (acac), the electron injection material 814 805 is formed. That is, the concentration gradient for Li (acac) is set steeply (although the electron injection material 814 is shown at a constant slope in the graph 810, the last part of this embodiment rises abruptly).
[239] Finally, aluminum is deposited to the cathode at a film thickness of about 150 nm to obtain a red light organic light emitting device derived from DCM.
[240] Example 10
[241] In the present embodiment, in the organic light emitting device illustrated in FIG. 29B, a hole injection region made of a hole injection material is inserted between the anode 2702 and the organic compound layer 2703, and electron injection is performed between the cathode 2704 and the organic compound layer. An example of an organic light emitting device obtained by inserting an electron injection region made of a material and applying a triple light emitting material as the light emitting material is described in detail. This device structure is shown in FIG.
[242] First, a glass substrate is prepared, on which ITO is deposited at about 100 nm by sputtering to form ITO (anode). The glass substrate with ITO is transferred to a vacuum chamber as shown in FIGS. 32A and 32B. In this embodiment, seven kinds of materials (five kinds of organic compounds and one kind of non-organic material forming a cathode) are deposited, so seven deposition sources are required.
[243] First, CuPc, which is a hole injection material, is deposited at a film thickness of 20 nm, and deposition of α-NPD, which is a hole transporting material, is 0.3 nm / sec, without an interval from the time of reaching 20 nm until the deposition of CuPC is completed. Starts with a ratio. The reason why deposition starts without such a gap is to prevent the formation of the impurity layer described above.
[244] After the hole transport layer composed only of α-NPD is formed to have a thickness of 30 nm, deposition of the electron transporting material BAlq starts with a deposition rate of 0.3 nm / sec, and the deposition rate of α-NPD is 0.3 nm / sec. Stays fixed. That is, a mixed region (α-NPD + BAlq) in which the ratio of α-NPD and BAlq is 1: 1 is formed by code localization.
[245] The mixed region is formed to have a film thickness of 20 nm, wherein in the middle region of the 10 nm film thickness (that is, 5 nm to 15 nm portion in the 20 nm mixed region), Ir (Triluminescent Material) ppy) ₃ is added. This addition ratio is α-NPD: BAlq: Ir (ppy) ₃ = 50: 50: 7.
[246] After the mixed region reaches a film thickness of 20 nm, deposition of α-NPD and Ir (ppy) ₃ is terminated, and only BAlq is subsequently deposited to form an electron transport region, which has a film thickness of 20 nm. From the time point when the deposition of BAlq is finished, the deposition of Alq ₃ , the electron injection material, begins at about 30 nm. The reason why deposition starts without such a gap is to prevent the formation of the impurity layer described above.
[247] Finally, LiF is deposited at about 1 nm and aluminum is deposited at about 150 nm to form a cathode to obtain a tri-light emitting device of green light originating from Ir (ppy) ₃ .
[248] Example 11
[249] In the present embodiment, the device obtained by applying the present invention to the triple light emitting diode shown in Fig. 9 will be described in detail. The device structure is shown in FIG. In addition, in this embodiment, a deposition source having a shutter shown in FIG. 11 is used to form the concentration gradient (graph 1010 of FIG. 10).
[250] First, ITO is deposited on the glass substrate 1001 at about 100 nm by sputtering to form the anode 1002. Subsequently, a hole transport mixed layer 1003 consisting of CuPc, which is a hole injection material 1011, and α-NPD, which is a hole transport material 1012, is deposited at 40 nm. At this time, by opening and closing the shutter, the concentration gradient as shown in the graph 1010 is formed.
[251] Subsequently, the bipolar-characteristic mixed layer 1004 composed of α-NPD and CBP and having a concentration gradient gradually increases the deposition rate of α-NPD, and 4-4'-N, which is a host material 1013 of the tri-luminescent material, It is formed to a thickness of 20 nm by increasing the deposition rate of N'-dicarbazole-biphenyl (hereinafter referred to as "CBP"). At this time, the stop mixed layer 1005 composed of CBP and BCP and having a concentration gradient is formed by reducing the deposition rate of CBP and increasing the deposition rate of BCP, which is the blocking material 1014. Thus, the resistant mixed layer has a film thickness of 10 nm.
[252] Since the present embodiment relates to a triple light emitting diode, tris (2-phenylpyridine) irridium (hereinafter referred to as Ir (ppy) ₃ ), which is a triple light emitting material 1016, is a bipolar-characteristic mixed layer 1004 and a stop mixed layer 1005. Is doped during formation. A region where the host material CBP is high in concentration, that is, a region near the boundary between the bipolar-characteristic mixed layer 1004 and the resistant mixed layer 1005 is most suitable as the doped region 1008. In this embodiment, an area of ± 5 nm near the boundary, that is, an area having a total width of 10 nm is made of the doped area 1008 when 6 wt% of doping is performed.
[253] In addition, the electron transporting mixed layer 1006 is composed of BCP and Alq ₃ , which has a high electron transporting capacity. The concentration gradient decreases as the concentration of BCP moves away from the anode, and is formed to increase in reverse as Alq ₃ moves away from the anode. That is, in this case, the BCP acts as a blocking material and the electron transporting material, and Alq ₃ acts as the electron injecting material 1015. The electron transporting mixed layer 1006 has a film thickness of 40 nm.
[254] Finally, an Al: Li alloy (0.5 wt% Li by weight) is deposited on the cathode at a film thickness of about 150 nm to form an organic light emitting device that presents green triplet light from Ir (ppy) ₃ . have.
[255] Example 12
[256] This embodiment describes a light emitting device comprising an organic light emitting element according to the present invention. 12A is a cross-sectional view of an active matrix light emitting device using the organic light emitting device of the present invention. A thin film transistor (hereinafter referred to as TFT) is used here as the active matrix, but the active element may be a MOS transistor.
[257] As an example, the illustrated TFT is an upper gate TFT (specifically, a flat TFT), but a lower gate TFT (typically a reverse stagger TFT) may be used instead.
[258] In FIG. 12A, 1201 represents a substrate. As used herein, the light beam may transmit visible light. In particular, glass substrates, quartz substrates, crystal glass substrates, or plastic substrates (including plastic films) can be used. The substrate 1201 refers to an insulating film + substrate formed on the surface of the substrate.
[259] The pixel portion 1211 and the driver circuit 1212 are provided over the substrate 1201. First, pixel portion 1211 is described.
[260] The pixel portion 1211 is an area for displaying an image. A plurality of pixels are placed on a substrate, and each pixel includes a TFT 1202 (hereinafter referred to as current control TFT) for controlling the current flowing through the organic light emitting element, a pixel electrode (anode) 1203, and an organic compound film ( 1204, and a cathode 1205 is provided. Although only the current control TFT is shown in Fig. 12A, each pixel has a TFT for controlling the voltage applied to the gate of the current control TFT (hereinafter referred to as a switching TFT).
[261] The current control TFT 1202 is preferably a p-channel TFT here. Although an n-channel TFT can be used instead, when the current control TFT is connected to the anode of the organic light emitting element as shown in Fig. 12A, the p-channel TFT with the current control TFT is more successful in reducing the current consumption. Note that the switching TFT can be formed as an n-channel TFT or a p-channel TFT.
[262] The drain of the current control TFT 1202 is electrically connected to the pixel electrode 1203. In this embodiment, since a conductive material having a work function of 4.5 to 5.5 eV is used as the material of the pixel electrode 1203, the pixel electrode 1203 operates as the anode of the organic light emitting element. As the pixel electrode 1203, a light transmitting material, typically indium oxide, tin oxide, zinc oxide, or a compound thereof (eg, ITO) is used. An organic compound film 1204 is formed on the pixel electrode 1203.
[263] The organic compound film 1204 is provided with a cathode 1205. The material of the cathode 1205 is preferably a conductive material having a working function of 2.5 to 3.5 eV. Typically, the cathode 1205 is formed of a conductive film containing an alkali metal element or an alkaline earth metal element, or a conductive film containing aluminum, or a laminate obtained by forming an aluminum or silver film on one of the conductive films. do.
[264] The layer composed of the pixel electrode 1203, the organic compound film 1204, and the cathode 1205 is covered with a protective film 1206. The protective film 1206 is provided to protect the organic light emitting device from oxygen and moisture. Materials that can be used for the protective film 1206 include silicon nitride, silicon oxynitride, aluminum oxide, tantalum oxide, and carbon (typically diamond type carbon).
[265] Next, the driving circuit 1212 is described. The driver circuit 1212 is an area for controlling the timing of the signals (gate signals and data signals) transmitted to the pixel portion 1211, and also includes an analog switch (transfer gate) or a shift register, a buffer, and a latch. Level shifts are provided. In Fig. 12A, the basic unit of these circuits is a CMOS circuit composed of an n-channel TFT 1207 and a p-channel TFT 1208.
[266] Known circuit structures can be applied to shift registers, buffers, latches, and analog switches (transfer gates) or level shifts. Although the pixel electrode 1211 and the driver circuit 1212 are provided on the same substrate in FIG. 12A, the IC or LSI may be electrically connected to the substrate instead of placing the driver circuit 1212 on the substrate.
[267] The pixel electrode (anode) 1203 is electrically connected to the current control TFT 1202 in Fig. 12A, but instead, the cathode may be connected to the current control TFT. In this case, the pixel electrode is formed from the material of the cathode 1205, and the cathode is formed from the material of the pixel electrode (anode) 1203. The current control TFT in this case is preferably an n-channel TFT.
[268] The light emitting device shown in FIG. 12A is fabricated by a process in which the formation of the pixel electrode 1203 precedes the formation of the wiring 1209. However, this process can roughen the surface of the pixel electrode 1203. Since the rough surface of the pixel electrode 1203 is a current-driven device, the characteristics of the organic light emitting device can be degraded.
[269] Subsequently, the pixel electrode 1203 is formed after forming the wiring 1209 to obtain the light emitting device shown in Fig. 12B. In this case, the current injection from the pixel electrode 1203 can be improved compared to the structure of Fig. 12A.
[270] 12A and 12B, the omni-taper bank structure 1210 separates the pixels lying in the pixel portion 1211 from each other. If this bank structure is reverse-tapered, contact between the bank structure and the pixel electrode can be prevented. An example thereof is shown in FIG. 34.
[271] In FIG. 34, the wiring also acts as a separating portion to form the wiring and the separating portion 3410. The formation of the wiring and isolation portions 3410 shown in FIG. 34 (ie, the eave structure) stacks the metal constituting the wiring with a material having lower etching conditions than the metal (for example, metal nitride), and then It is obtained by etching the lamination. This shape can prevent a short circuit between the cathode 3405 and the pixel electrode 3403 or the wiring. Unlike a conventional active matrix light emitting device, the cathode 3405 of the pixel is striped in the device of FIG. 34 (similar to the cathode of an active matrix device).
[272] 13A and 13B show the appearance of the active matrix light emitting device shown in FIG. 12B. FIG. 13A is a top view and FIG. 13B is a sectional view taken along the line P-P 'of FIG. 13A. The symbols of FIGS. 12A and 12B are used in FIGS. 13A and 13B.
[273] In Fig. 13A, 1301 denotes a pixel portion, 1302 denotes a gate signal side driving circuit, and 1303 denotes a data signal side driving circuit. The signals transmitted to the gate signal side driver circuit 1302 and the data signal side driver circuit 1303 are input from a tape automated bonding (TAB) tape 1305 through the input wiring 1304. Although not shown in the figure, the TAB tape 1305 may be replaced with a tape carrier package (TCP) obtained by providing a TAB tape in an integrated circuit (IC).
[274] 1306 is a cover member provided at the top portion of the light emitting device shown in FIG. 12B and engaged with a sealing member 1307 made of resin. Cover member 1306 may be any material that does not permeate oxygen and moisture. In the present embodiment, as shown in Fig. 13B, the cover member 1306 is composed of a plastic member 1306a and carbon films (especially diamond-shaped carbon films) 1306b and 1306c formed before and after the plastic member 1306a, respectively. do.
[275] As shown in FIG. 13B, the sealing member 1307 is covered with a sealing member 1308 made of resin such that the organic light emitting device is completely sealed in the sealed space 1309. Enclosed space 1309 is filled with an inert gas (typically nitrogen gas or a rare gas), a resin, or an inert liquid (e.g., liquid crystalline fluorocarbons of which typical example is perfluoro alkane). In addition, it is also effective to add a moisture absorbent or an oxygen scavenger into the space.
[276] In this embodiment, a polarizing plate may be provided on the display surface of the light emitting device (the surface on which the image is displayed and viewed by the viewer). The polarizing plate has the effect of reducing the reflection of incident light from the outside, thereby preventing the display surface from being shown reflected by the viewer. Generally, a rotating polarizing plate is used. However, in order to prevent the light emitted from the organic compound film from reflecting back from the polarizing plate and moving back, it is preferable that the polarizing plate has a structure having less internal reflection by adjusting the refractive index.
[277] The organic light emitting device according to the present invention can be used as the organic light emitting device included in the light emitting device of this embodiment.
[278] Example 13
[279] This embodiment shows an active matrix light emitting device as an example of a light emitting device comprising an organic light emitting element according to the present invention. Unlike Embodiment 12, in the light emitting device of this embodiment, light is given from the opposite side of the substrate on which the active element is formed (hereinafter referred to as upward emission). 35 is a cross-sectional view thereof.
[280] A thin film transistor (hereinafter referred to as TFT) is used here as the active element, but the active element can be a MOS transistor. The TFT shown as an example is an upper gate TFT (specifically, a flat TFT), but a lower gate TFT (typically an inverse stagger TFT) may be used instead.
[281] The substrate 3501 of this embodiment, the current control TFT 3502 formed in the pixel portion, and the driving circuit 3512 have the same structure as in the fifth embodiment.
[282] Since the first electrode 3503 connected to the drain of the current control TFT 3502 is used as the anode in this embodiment, it is preferably formed of a conductive material having a large working function. Typical examples of conductive materials include metals such as nickel, palladium, tungsten, gold, and silver. In this embodiment, the first electrode 3503 preferably does not transmit light. More preferably, the electrode is formed of a material that reflects a lot of light.
[283] An organic compound film 3504 is formed on the first electrode 3503. The organic compound film 3504 is provided with a second electrode 3505 that acts as a cathode in this embodiment. Thus, the material of the second electrode 3505 is preferably a conductive material having a working function of 2.5 to 3.5 eV. Typically, a conductive film containing an alkali metal element or an alkaline-earth metal element, a conductive film containing aluminum, or a laminate obtained by stacking an aluminum or silver film on one of the conductive films is used. However, light transmittance is essential as the material of the second electrode 3505. Therefore, when used as the second electrode, the metal is preferably formed in a very thin film with a thickness of about 20 nm.
[284] The layer composed of the first electrode 3503, the organic compound film 3504, and the second electrode 3505 is covered with a protective film 3606. The protective film 3506 is provided to protect the organic light emitting device from oxygen and moisture. In this embodiment, any material that transmits light can be used as the protective film.
[285] The first electrode (anode) 3503 is electrically connected to the current control TFT 3502 in FIG. 35, but instead, the cathode can be connected to the current control TFT. In this case, the first electrode is formed of the material of the cathode, and the second electrode is formed of the material of the anode. In this case, the current control TFT is preferably an n-channel TFT.
[286] 3507 is a cover member and is joined to a sealing member 3508 formed of resin. The cover member 3507 can be any material that transmits light except coral and moisture. In this embodiment, glass is used. Enclosed space 3509 is filled with an inert gas (typically nitrogen gas or rare gas), a resin, or an inert liquid (e.g., liquid crystalline fluorocarbons of which typical example is perfluoro alkane). In addition, it is also effective to add a moisture absorbent or an oxygen scavenger into the space.
[287] The signal transmitted to the gate signal side driving circuit and the data signal side driving circuit is input from a tape automated bonding (TAB) tape 3514 via the input wiring 3513. Although not shown in the figure, the TAB tape 3514 may be replaced with a tape carrier package (TCP) obtained by providing a TAB tape to an integrated circuit (IC).
[288] In this embodiment, a polarizing plate may be provided on the display surface of the light emitting device (the surface on which the image is displayed and viewed by the viewer). The polarizing plate has the effect of reducing the reflection of incident light from the outside, thereby preventing the display surface from being shown reflected by the viewer. Generally, a rotating polarizing plate is used. However, in order to prevent the light emitted from the organic compound film from reflecting back from the polarizing plate and moving back, it is preferable that the polarizing plate has a structure having less internal reflection by adjusting the refractive index.
[289] The organic light emitting element according to the present invention can be used as the organic light emitting element included in the light emitting device of this embodiment.
[290] Example 14
[291] This embodiment shows a passive matrix light emitting device as an example of a light emitting device including the organic light emitting element described in the present invention. FIG. 14A is a top view and FIG. 14B is a sectional view taken along the line P-P 'of FIG. 14A.
[292] In FIG. 14A, 1401 denotes a substrate formed of a plastic material here. Plastic materials that can be used are plates or membranes of polyimide, polyamide, acrylic resins, epoxy resins, polyethylene sulfile (PES), polycarbonate (PC), polyethylene terephthalate (PET), or polyethylene naphthalate (PEN) .
[293] 1402 denotes a scanning line (anode) formed of an oxide conductive film. In this embodiment, the conductive oxide film is obtained by doping zinc oxide with gallium oxide. 1403 denotes a data line (cathode) formed of a metal film and a bismuth film in this embodiment. 1404 denotes a bank formed of an acrylic resin. The bank acts as a partition wall separating the data lines 1403 from each other. The scanning line 1402 and the data line 1403 each form a stripe pattern, and the patterns vertically cross each other. Although not shown in FIG. 14A, the organic compound film is sandwiched between the scan line 1402 and the data line 1403, and the intersection 1405 operates as a pixel.
[294] The scanning line 1402 and the data line 1403 are connected to the external driving circuit through the TAB tape 1407. Reference numeral 1408 denotes a wiring group composed of many scan lines 1402. 1409 denotes a wiring group composed of many connecting wires 1406 connected to the data lines 1403. Although not shown, the TAB tape 1407 can be replaced with TCP, which is obtained by providing a TAB tape to the IC.
[295] In FIG. 14B, 1410 represents a closure member and 1411 represents a cover member coupled to the plastic member 1401 with a closure member 1410. Photocurable resin may be used as the sealing member 1410. Preferred materials for the sealing member are those that allow little gas leakage and absorb little moisture. The cover member is preferably made of the same material as the substrate 1401, and glass (including quartz glass) or plastic may be used. Plastic materials are used here as cover materials.
[296] 14C is an enlarged view of a structure of a pixel region. 1413 denotes an organic compound film. Since the bottom layer of the bank 1404 is narrower than the top layer, the bank can physically separate the data lines 1403 from each other. The pixel portion 1414 surrounded by the sealing member 1410 is isolated from external air by the sealing member 1415 formed of resin. Thus, deformation of the organic compound film is prevented.
[297] In the light emitting device constructed as described above according to the present invention, the pixel portion 1414 is composed of the scan line 1402, the data line 1403, the bank 1404, and the organic compound film 1413. Therefore, the light emitting device can be manufactured by a very simple process.
[298] A polarizing plate may be provided on the display surface (the surface on which an image is displayed and viewed by the viewer) of the light emitting device shown in this embodiment. The polarizing plate has the effect of reducing the reflection of incident light from the outside, thereby preventing the display surface from being shown reflected by the viewer. Generally, circular polarizers are used. However, in order to prevent the light emitted from the organic compound film from reflecting back from the polarizing plate and moving back, it is preferable that the polarizing plate has a structure having less internal reflection by adjusting the refractive index.
[299] The organic light emitting device according to the present invention can be used as the organic light emitting device included in the light emitting device of this embodiment.
[300] Example 15
[301] This embodiment shows an example of attaching a printed wiring board to the light emitting device shown in Example 14 to make the device into a module.
[302] In the module shown in FIG. 15A, a TAB tape 1504 is attached to a substrate 1501 (which includes pixel portions 1502 and wiring 1503a, 1503b), and the printed wiring mode 1505 is a TAB tape ( Is attached to the substrate via 1504.
[303] A functional block diagram of the printed wiring board 1505 is shown in FIG. 15B. The printed wiring board 1505 is provided with an IC that operates at least as an I / O port (input or output portion) 1506 and 1509, a data signal side driver circuit 1507, and a gate signal side driver circuit 1508. .
[304] In the present specification, a module configured by attaching a TAB tape to a substrate having a pixel portion formed on its surface and attaching a printed wiring board operating as a driving circuit to the substrate through the TAB tape as described above is specifically referred to as a module having an external driving circuit. Lose.
[305] The organic light emitting element described in the present invention can be used as the organic light emitting element included in the light emitting device of this embodiment.
[306] Example 16
[307] This embodiment shows an example of attaching a printed wiring board to the light emitting device shown in Embodiment 12, 13, or 14 to make the device into a module.
[308] In the module shown in FIG. 16A, the TAB tape 1605 is formed of a substrate 1601 (here, the pixel portion 1602, the data signal side driver circuit 1603, the gate signal side driver circuit 1604, and the wiring 1603a, 1603b. ), And the printed wiring board 1606 is attached to the substrate via the TAB tape 1605. A functional block diagram of the printed wiring board 1606 is shown in FIG. 16B.
[309] As shown in FIG. 16B, an IC that operates as at least I / O ports 1607 and 1610 and a control unit 1608 is provided in the printed wiring board 1606. The memory unit 1609 is not provided here, but is not always necessary. The control unit 1608 has a function for controlling the driving circuit and correcting the image data.
[310] In this specification, a module configured by attaching a printed wiring board acting as a controller to a substrate on which an organic light emitting element is formed as described above is specifically referred to as a module having an external controller.
[311] The organic light emitting element described in the present invention can be used as the organic light emitting element included in the light emitting device of this embodiment.
[312] Example 17
[313] This embodiment shows an example of a light emitting device in which the triple light emitting diodes shown in Embodiments 10 and 11 are driven in accordance with a digital gray scale display. The light emitting device of the present invention is useful because it can provide a uniform image in a digital time gray scale display by using light emission from a triple excited state.
[314] 36A shows a circuit structure of a pixel using an organic light emitting element. Tr represents a transistor and Cs represents a storage capacitor. In this circuit, when the gate line is selected, current flows from Tr1 to the source line, and a voltage corresponding to the signal is accumulated in Cs. The current controlled by the gate-source voltage V _gs of Tr2 then flows into Tr2 and the organic light emitting device.
[315] After Tr1 is selected, Tr1 goes OFF to maintain the voltage V _{gs of} Cs. Thus, the current continues to flow in an amount dependent on V _gs .
[316] 36B shows a chart for driving this circuit in accordance with a digital time gray scale display. In digital time gray scale display, one frame is divided into a number of sub-frames. 36B shows a six bit gray scale in which one frame is divided into six sub-frames. In this case, the light emission period of the sub-frame is 32: 16: 8: 4: 2: 1.
[317] 36C shows the driving circuit of the TFT substrate in this embodiment. The gate driver and the source driver are provided on the same substrate. In this embodiment, the pixel circuit and the driver are designed to be digitally driven. Thus, variations in TFT characteristics do not affect the device, and the device can display a uniform image.
[318] Example 18
[319] The light emitting device of the present invention described in the above embodiment has the advantage of low power consumption and long life. Thus, electronic products including these light emitting devices as display units last longer because they can be operated with less power than conventional ones. This is particularly useful for electronics that use batteries as the power source, such as portable equipment, because low power consumption directly provides convenience (because the battery lasts longer).
[320] The light emitting device emits light by itself, thus eliminating the need for a back light such as a liquid crystal display and having an organic compound layer having a thickness of 1 μm or less. Therefore, the light emitting device can be made thin and light. Electronic products comprising light emitting devices as display units are thus thinner and lighter than conventional ones. This provides direct convenience (lightness and simplicity in transport) and is particularly useful for portable equipment and other electronic products. In addition, the thinner (smaller volume), of course, is useful for all electronic products during transportation (large number of products can be transported) and installation (space saving).
[321] Since it emits light by itself, the light emitting device is characterized by having better visibility in a bright place and wider viewing angle than a liquid crystal display device. Therefore, an electronic product including a light emitting device as a display unit is also very useful in terms of convenience when watching a display.
[322] In summary, electronic products using the light emitting device of the present invention are very useful because they have new characteristics of low power consumption and long life, in addition to the advantages of conventional organic light emitting devices, namely thinness / lightness and high visibility.
[323] This embodiment shows an example of an electronic product including the light emitting device of the present invention as a display unit. Specific examples thereof are shown in Figs. 17A to 17F and Figs. 18A and 18B. The metal composite described in the present invention can be used as an organic light emitting device included in the electronic product of this embodiment. The light emitting device included in the electronic product of the present embodiment may have any of the configurations described in FIGS. 12 to 16 and 34 to 36.
[324] 17A shows a display device using an organic light emitting element. The display is composed of a case 1701a, a support base 1702a, and a display unit 1703a. By using the light emitting device of the present invention as the display unit 1703a, the display is not only thin and light but also long lasting. Therefore, transportation is simple, space is saved during installation, and life is extended.
[325] FIG. 17B shows a video camera, which is composed of a main body 1701b, a display unit 1702b, an audio input unit 1703b, an operation switch 1704b, a battery 1705b, and an image receiving unit 1706b. . By using the light emitting device of the present invention as the display unit 1702b, the video camera can be thin and light, and consumes less power. Thus, battery consumption is reduced and transportation of the video camera is less inconvenient.
[326] 17C shows a digital camera, and is composed of a main body 1701c, a display unit 1702c, an eyepiece unit 1703c, and an operation switch 1704c. By using the light emitting device of the present invention as the display unit 1702c, the digital camera can be thin and light, and consumes less power. Thus, battery consumption is reduced and transportation of the digital camera is less inconvenient.
[327] 17D shows an image reproducing device equipped with a recording medium. The device consists of a main body 1701d, a recording medium (such as a CD, LD, or DVD) 1702d, an operation switch 1703d, a display unit (A) 1704d, and a display unit (B) 1705d. do. The display unit (A) 1704d mainly displays image information, and the display unit (B) 1705d mainly displays text information. By using the light emitting device of the present invention as the display unit (A) 1704d and the display unit (B) 1705d, the image reproducing device consumes less power, can be thin and light as well as long-lasting. An image reproducing device equipped with a reproducing medium also includes a CD player and a game machine.
[328] FIG. 17E shows a (portable) mobile computer, which is composed of a main body 1701e, a display unit 1702e, an image receiving unit 1703e, a switch 1704e, and a memory slot 1705e. By using the light emitting device of the present invention as the display unit 1702e, the portable computer can be thin and light, and consumes less power. Thus, battery consumption is reduced, and transportation of the computer is less inconvenient. The portable computer can store information in a recording medium or flash memory obtained by aggregating nonvolatile memory, and can reproduce the stored information.
[329] 17F shows a personal computer, which is composed of a main body 1701f, a case 1702f, a display unit 1703f, and a keyboard 1704f. By using the light emitting device of the present invention as the display unit 1703f, the personal computer can be thin and light, and consumes less power. The light emitting device has particular advantages over notebook personal computers or other personal computers that are carried in terms of battery consumption and light weight.
[330] These electronic products now increase and display frequency information, especially animation information, transmitted via wireless communications such as radio waves and electronic communication lines such as the Internet. Since the organic light emitting element has a very fast response speed, the light emitting device is suitable for animation display.
[331] 18A shows a mobile phone, which is composed of a main body 1801a, an audio output unit 1802a, an audio input unit 1803a, a display unit 1804a, an operation switch 1805a, and an antenna 1806a. By using the light emitting device of the present invention as the display unit 1804a, the cellular phone can be thin and light, and consumes less power. Therefore, battery consumption is reduced, the portable of the mobile phone is comfortable, and the main body is concise.
[332] 18B shows audio (specifically, car audio), which is composed of a main body 1801b, a display unit 1802b, and operation switches 1803b, 1804b. By using the light emitting device of the present invention as the display unit 1802b, the audio can be thin and light, and consumes less power. Although car audio is taken as an example in this embodiment, the audio may be home audio.
[333] When an electronic product is used by providing an optical sensor to the electronic product as a means for measuring the brightness of the surroundings, the brightness of light irradiated according to the ambient brightness is applied to the electronic products shown in FIGS. 37A to 17F and 18A and 18B. It is effective to be given the ability to modulate When the contrast ratio of the luminance of the irradiated light to the ambient brightness is 100 to 150, the user may recognize the image or text information without difficulty. With this function, the brightness of the image can be raised for better viewing when the surroundings are bright, and lowered to reduce power consumption when the surroundings are dark.
[334] Various electronic products using the light emitting device of the present invention as a light source can also be thin, light, and operate to consume less power, making the electronic products very useful. A light source or a fixed light source of a liquid crystal display device, such as a front and rear light, typically makes a typical use of the light emitting device of the present invention as a light source.
[335] When the liquid crystal display is used as the display unit of the electronic products shown in Figs. 17A to 17F and Figs. 18A and 18B according to the present embodiment, when these liquid crystal displays use the light emitting device of the present invention as front and rear lights, Can be thin and light and consumes less power.
[336] Example 19
[337] In this embodiment, an example of an active matrix type constant-current driving circuit is described, which is driven by flowing a constant current through the organic light emitting element of the present invention. The circuit structure is shown in FIG.
[338] The pixel 1810 shown in FIG. 37 has a signal line Si, a first scanning line Gj, a second scanning line Pj, and a power source line Vi. In addition, the pixel 1810 has transistors Tr1, Tr2, Tr3, Tr4, a mixed junction organic light emitting device 1811, and a retention capacitor 1812.
[339] The gates of Tr3 and Tr4 are both connected to the first scan line Gj. For the source and drain of Tr3, one is connected to the signal line Si and the other is connected to the source of Tr2. Also, at the source and drain of Tr4, one is connected to the source of Tr2 and the other to the gate of Tr1. Thus, either one of the source and drain of Tr3 and one of the source or drain of Tr4 are connected to each other.
[340] The source of Tr1 is connected to the power source line Vi, and the drain is connected to the source of Tr2. The gate of Tr2 is connected to the second scan line Pj. In addition, the drain of Tr2 is connected to the pixel electrode of the organic light emitting device 1811. The organic light emitting element 1811 has a pixel electrode, a counter electrode, and an organic light emitting element provided between the pixel electrode and the counter electrode. A constant voltage is applied to the counter electrode of the organic light emitting element 1811 as a power source provided outside the light emitting panel.
[341] Tr3 and Tr4 can adopt both n-channel type TFT and p-channel type TFT. However, the polarities of Tr3 and Tr4 are the same. In addition, Tr1 can adopt both n-channel type TFT and p-channel type TFT. Tr2 can also adopt both n-channel type TFT and p-channel type TFT. For polarity, in the case of the pixel electrode and the counter electrode of the light emitting electrode, one is the anode and the other is the cathode. When Tr2 is an n-channel type TFT, it is preferable to use the cathode as the pixel electrode and the anode as the counter electrode.
[342] Retention capacitor 1812 is formed between the gate and the source of Tr1. Retention capacitor 1812 is provided to maintain voltage VGS more specifically between the gate and the source of Tr1. However, it does not always need to be provided.
[343] In the pixel shown in FIG. 37, the current supplied to the signal line Si is controlled at the current source of the signal line driver circuit.
[344] By applying the above-described circuit structure, constant-current driving can be realized, whereby brightness can be maintained by flowing a constant current through the organic light emitting element. The organic light emitting device having the mixed region of the present invention has a longer lifetime than previous organic light emitting devices. The organic light emitting element is effective because a longer lifetime can be realized by carrying out the above-described constant-current driving.
[345] The present invention is practiced to provide a light emitting device with low power consumption and extended life. Further, by using such a light emitting device as a light source or a display unit, bright, low power consumption and long lasting electronic products can be obtained.
[346] The present invention improves carrier mobility by maximizing the advantages (separation of function) in the conventionally used laminated structure and mitigating the energy barrier applied to the organic layer, and lowering the driving voltage and extending the lifespan than in the prior art. A device can be provided. In particular, the present invention eliminates the organic interface given to the organic compounding layer, improves the mobility of the carrier, and at the same time provides a layered structure by fabricating a device having a concept different from that of the conventionally used laminated structure in which the carrier of the light emitting layer is blocked for recombination. The functionality of a number of different materials can be realized in the same manner as the functional separation involved, and the present invention can also use such organic light emitting devices to provide light emitting devices with lower drive voltages and longer lifetimes than in the prior art. . In addition, the present invention can be made with the use of such a light emitting device to provide an electronic product that consumes less power and lasts longer than in the prior art.

权利要求:
Claims (128)
[1" claim-type="Currently amended] A light emitting device comprising an organic luminescent element,
Anode,
Cathode, and
A hole transport layer provided between the anode and the cathode and comprising a first compound and a second compound,
The first compound has a lower ionization potential than the second compound,
And the second compound has greater hole mobility than the first compound.
[2" claim-type="Currently amended] The method of claim 1,
And a concentration gradient in which the concentration of the first compound is reduced from the anode toward the cathode and the concentration of the second compound is increased from the anode toward the cathode.
[3" claim-type="Currently amended] The method of claim 1,
The first compound comprises a phthalocyanine compound, a light emitting device.
[4" claim-type="Currently amended] The method of claim 1,
Wherein the second compound comprises an aromatic amine-based compound.
[5" claim-type="Currently amended] The method of claim 1,
And the organic light emitting device has light emission from a triple excited state.
[6" claim-type="Currently amended] The method of claim 1,
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[7" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
Cathode, and
An electron transporting layer provided between said anode and said cathode and comprising a first compound and a second compound,
The first compound has a higher electron affinity than the second compound,
Wherein the second compound has greater electron mobility than the first compound.
[8" claim-type="Currently amended] The method of claim 7, wherein
And a concentration gradient in which the concentration of the first compound is increased from the anode toward the cathode and the concentration of the second compound is decreased from the anode toward the cathode.
[9" claim-type="Currently amended] The method of claim 7, wherein
The first compound is selected from the group consisting of an alkali metal halogen compound, a metal complex having a quinoline skeleton, a metal complex having a benzoquinoline skeleton, an oxadiazole derivative, or a triazole derivative. Selected light emitting device.
[10" claim-type="Currently amended] The method of claim 7, wherein
Wherein said second compound is selected from the group consisting of metal complexes with a quinoline skeleton, metal complexes with a benzoquinoline skeleton, oxadiazole derivatives, triazole derivatives, or phenanthroline derivatives.
[11" claim-type="Currently amended] The method of claim 7, wherein
And the organic light emitting device has light emission from a triple excited state.
[12" claim-type="Currently amended] The method of claim 7, wherein
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[13" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
Cathode, and
A light emitting layer provided between the anode and the cathode and including a first compound and a second compound,
The first compound has greater hole mobility than the second compound,
And the second compound has greater electron mobility than the first compound.
[14" claim-type="Currently amended] The method of claim 13,
And a concentration gradient in which the concentration of the first compound is reduced from the anode toward the cathode and the concentration of the second compound is reduced from the anode toward the cathode.
[15" claim-type="Currently amended] The method of claim 13,
Wherein the first compound comprises an aromatic amine-based compound.
[16" claim-type="Currently amended] The method of claim 13,
Wherein said second compound is selected from the group consisting of a metal complex with a quinoline skeleton, a metal complex with a benzoquinoline skeleton, an oxadiazole derivative, a triazole derivative, or a phenanthroline derivative.
[17" claim-type="Currently amended] The method of claim 13,
And the organic light emitting device has light emission from a triple excited state.
[18" claim-type="Currently amended] The method of claim 13,
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[19" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
Cathode, and
A light emitting layer provided between the anode and the cathode and including a first compound, a second compound, and a third compound,
The first compound has higher hole mobility than the second compound,
The second compound has higher electron mobility than the first compound,
The energy difference between the highest occupied molecular orbit and the lowest unoccupied molecular orbit in the third compound is determined by the highest occupied molecular orbit and the lowest ratio in the second compound. A light emitting device, which is smaller than the energy difference between occupied molecular orbits.
[20" claim-type="Currently amended] The method of claim 19,
And a concentration gradient in which the concentration of the first compound is reduced from the anode toward the cathode and the concentration of the second compound is increased from the anode toward the cathode.
[21" claim-type="Currently amended] The method of claim 19,
Wherein the first compound comprises an aromatic amine-based compound.
[22" claim-type="Currently amended] The method of claim 19,
Wherein said second compound is selected from the group consisting of a metal complex with a quinoline skeleton, a metal complex with a benzoquinoline skeleton, an oxadiazole derivative, a triazole derivative, or a phenanthroline derivative.
[23" claim-type="Currently amended] The method of claim 19,
And the organic light emitting device has light emission from a triple excited state.
[24" claim-type="Currently amended] The method of claim 19,
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[25" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
cathode,
A light emitting layer provided between the anode and the cathode, and
A blocking layer adjacent to the light emitting layer and provided between the anode and the cathode,
The block layer includes a material and a blocking material included in the light emitting layer,
Wherein the energy difference between the highest and lowest unoccupied molecular orbits in the blocking material is greater than the energy difference between the highest and lowest unoccupied molecular orbits in the material contained in the emissive layer.
[26" claim-type="Currently amended] The method of claim 25,
And a concentration gradient in which the concentration of the material contained in the light emitting layer is reduced from the anode toward the cathode and the concentration of the blocking material is increased from the anode toward the cathode.
[27" claim-type="Currently amended] The method of claim 25,
The blocking material is selected from the group consisting of oxadiazole derivatives, triazole derivatives, or phenanthroline derivatives.
[28" claim-type="Currently amended] The method of claim 25,
And the organic light emitting device has light emission from a triple excited state.
[29" claim-type="Currently amended] The method of claim 25,
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[30" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
Cathode, and
An organic compound layer provided between said anode and said cathode, said organic compound layer comprising a hole transport region comprising a hole transport material and an electron transport region comprising an electron transport material,
The hole transport region is disposed closer to the anode than the electron transport region,
And a mixed region comprising the hole transport material and the electron transport material is provided between the hole transport region and the electron transport region.
[31" claim-type="Currently amended] The method of claim 30,
And a concentration gradient in which the concentration of the hole transport material is reduced from the anode to the cathode and the concentration of the electron transport material is increased from the anode to the cathode in the mixing region.
[32" claim-type="Currently amended] The method of claim 30,
Wherein the luminescent material is doped into the mixed region.
[33" claim-type="Currently amended] The method of claim 30,
Wherein the luminescent material is doped in a portion of the mixed region.
[34" claim-type="Currently amended] The method of claim 30,
And the energy difference between the highest occupied molecular trajectory and the lowest unoccupied molecular trajectory in the mixed region is greater than the energy difference in the hole transporting material and the electron transporting material.
[35" claim-type="Currently amended] The method of claim 34, wherein
A light emitting device, characterized in that a blocking material is doped in some of the mixed regions.
[36" claim-type="Currently amended] The method of claim 34, wherein
And a light emitting material and a blocking material are doped in the mixed region.
[37" claim-type="Currently amended] The method of claim 36,
And the partially added light emitting material is disposed closer to the anode than the partially added blocking material.
[38" claim-type="Currently amended] The method according to any one of claims 32, 33, 34, 36, 37,
Wherein the light emitting material provides light emission from a triple excited state.
[39" claim-type="Currently amended] The method of claim 36,
Wherein the ratio of the mass of the hole transport material to the total mass of the hole transport material and the electron transport material in the mixing zone is at least 10% and at most 90%.
[40" claim-type="Currently amended] The method of claim 36,
Wherein said mixed region is at least 10 nm and has a thickness of at most 100 nm.
[41" claim-type="Currently amended] The method of claim 25,
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[42" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
cathode,
A hole injection region adjacent the anode, and
An organic compound layer provided between said hole injection region and said cathode, said organic compound layer comprising a hole transport region comprising a hole transport material and an electron transport region comprising an electron transport material,
The hole transport region is disposed closer to the anode than the electron transport region,
And a mixed region comprising the hole transport material and the electron transport material is provided between the hole transport region and the electron transport region.
[43" claim-type="Currently amended] The method of claim 42,
And a concentration gradient in which the concentration of the hole transport material is reduced from the anode to the cathode and the concentration of the electron transport material is increased from the anode to the cathode in the mixing region.
[44" claim-type="Currently amended] The method of claim 42,
Wherein the luminescent material is doped into the mixed region.
[45" claim-type="Currently amended] The method of claim 42,
Wherein the luminescent material is doped in a portion of the mixed region.
[46" claim-type="Currently amended] The method of claim 42,
And the energy difference between the highest occupied molecular trajectory and the lowest unoccupied molecular trajectory in the mixed region is greater than the energy difference in the hole transporting material and the electron transporting material.
[47" claim-type="Currently amended] The method of claim 46,
Wherein the blocking material is doped in a portion of the mixed region.
[48" claim-type="Currently amended] The method of claim 46,
And a light emitting material and a blocking material are doped in the mixed region.
[49" claim-type="Currently amended] 49. The method of claim 48 wherein
And the partially added light emitting material is disposed closer to the anode than the partially added blocking material.
[50" claim-type="Currently amended] The method according to any one of claims 44 or 45 or 48 or 49,
Wherein the light emitting material provides light emission from a triple excited state.
[51" claim-type="Currently amended] 49. The method of claim 48 wherein
Wherein the ratio of the mass of the hole transport material to the total mass of the hole transport material and the electron transport material in the mixing zone is at least 10% and at most 90%.
[52" claim-type="Currently amended] 49. The method of claim 48 wherein
Wherein said mixed region is at least 10 nm and has a thickness of at most 100 nm.
[53" claim-type="Currently amended] The method of claim 42,
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[54" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
cathode,
An electron injection region in contact with the cathode, and
An organic compound layer provided between said anode and said electron injection region, said organic compound layer comprising a hole transport region comprising a hole transport material and an electron transport region comprising an electron transport material,
The hole transport region is disposed closer to the anode than the electron transport region,
And a mixed region comprising the hole transport material and the electron transport material is provided between the hole transport region and the electron transport region.
[55" claim-type="Currently amended] The method of claim 54, wherein
And a concentration gradient in which the concentration of the hole transport material is reduced from the anode to the cathode and the concentration of the electron transport material is increased from the anode to the cathode in the mixing region.
[56" claim-type="Currently amended] The method of claim 54, wherein
Wherein the luminescent material is doped into the mixed region.
[57" claim-type="Currently amended] The method of claim 54, wherein
Wherein the luminescent material is doped in a portion of the mixed region.
[58" claim-type="Currently amended] The method of claim 54, wherein
And the energy difference between the highest occupied molecular trajectory and the lowest unoccupied molecular trajectory in the mixed region is greater than the energy difference in the hole transporting material and the electron transporting material.
[59" claim-type="Currently amended] The method of claim 58,
Wherein the blocking material is doped in a portion of the mixed region.
[60" claim-type="Currently amended] The method of claim 58,
And a light emitting material and a blocking material are doped in the mixed region.
[61" claim-type="Currently amended] The method of claim 60,
And the partially added light emitting material is disposed closer to the anode than the partially added blocking material.
[62" claim-type="Currently amended] 62. The method of any one of claims 56 or 57 or 60 or 61,
Wherein the light emitting material provides light emission from a triple excited state.
[63" claim-type="Currently amended] The method of claim 60,
Wherein the ratio of the mass of the hole transport material to the total mass of the hole transport material and the electron transport material in the mixing zone is at least 10% and at most 90%.
[64" claim-type="Currently amended] The method of claim 60,
Wherein said mixed region is at least 10 nm and has a thickness of at most 100 nm.
[65" claim-type="Currently amended] The method of claim 54, wherein
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[66" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
cathode,
A hole injection region adjacent to the anode,
An electron injection region adjacent the cathode, and
An organic compound layer provided between said hole injection region and said electron injection region, said organic compound layer comprising a hole transport region comprising a hole transport material and an electron transport region comprising an electron transport material,
The hole transport region is disposed closer to the anode than the electron transport region,
And a mixed region comprising the hole transport material and the electron transport material is provided between the hole transport region and the electron transport region.
[67" claim-type="Currently amended] The method of claim 66, wherein
And a concentration gradient in which the concentration of the hole transport material is reduced from the anode to the cathode and the concentration of the electron transport material is increased from the anode to the cathode in the mixing region.
[68" claim-type="Currently amended] The method of claim 66, wherein
Wherein the luminescent material is doped into the mixed region.
[69" claim-type="Currently amended] The method of claim 66, wherein
Wherein the luminescent material is doped in a portion of the mixed region.
[70" claim-type="Currently amended] The method of claim 66, wherein
And the energy difference between the highest occupied molecular trajectory and the lowest unoccupied molecular trajectory in the mixed region is greater than the energy difference in the hole transporting material and the electron transporting material.
[71" claim-type="Currently amended] The method of claim 70,
Wherein the blocking material is doped in a portion of the mixed region.
[72" claim-type="Currently amended] The method of claim 70,
And a light emitting material and a blocking material are doped in the mixed region.
[73" claim-type="Currently amended] The method of claim 72,
And the partially added light emitting material is disposed closer to the anode than the partially added blocking material.
[74" claim-type="Currently amended] 74. The method of any of claims 69 or 70 or 72 or 73,
Wherein the light emitting material provides light emission from a triple excited state.
[75" claim-type="Currently amended] The method of claim 72,
Wherein the ratio of the mass of the hole transport material to the total mass of the hole transport material and the electron transport material in the mixing zone is at least 10% and at most 90%.
[76" claim-type="Currently amended] The method of claim 72,
Wherein said mixed region is at least 10 nm and has a thickness of at most 100 nm.
[77" claim-type="Currently amended] The method of claim 66, wherein
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[78" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
Cathode, and
An organic compound layer provided between said anode and said cathode, said organic compound layer comprising a hole transport region comprising said hole transport material and an electron transport region comprising an electron transport material,
A mixing region is provided between the hole transport region and the electron transport region, and includes the hole transport material and the electron transport material,
A light emitting device provided with a light emitting material added to the mixed region.
[79" claim-type="Currently amended] The method of claim 78,
And the mixing region comprises the hole transport material and the electron transport material in a proportion.
[80" claim-type="Currently amended] The method of claim 78,
And a part of the mixed region is the light emitting region.
[81" claim-type="Currently amended] The method of claim 78,
A light emitting device, wherein a portion of the mixed region is doped with a blocking material, wherein the energy difference between the highest occupied and lowest unoccupied molecular trajectory is large compared to the energy difference in the hole transport material and the electron transport material.
[82" claim-type="Currently amended] 82. The method of claim 81 wherein
And the light emitting area is disposed closer to the anode than the portion to which the blocking material is added.
[83" claim-type="Currently amended] The method of claim 78,
Wherein the light emitting material provides light emission from a triple excited state.
[84" claim-type="Currently amended] The method of claim 78,
Wherein the ratio of the mass of the hole transport material to the total mass of the hole transport material and the electron transport material in the mixing zone is at least 10% and at most 90%.
[85" claim-type="Currently amended] The method of claim 78,
Wherein said mixed region is at least 10 nm and has a thickness of at most 100 nm.
[86" claim-type="Currently amended] The method of claim 78,
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[87" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
cathode,
A hole injection region adjacent the anode, and
An organic compound layer provided between said hole injection region and said cathode, said organic compound layer comprising a hole transport region comprising said hole transport material and an electron transport region comprising said electron transport material,
A mixing region is provided between the hole transport region and the electron transport region, and includes the hole transport material and the electron transport material,
A light emitting device provided with a light emitting material added to the mixed region.
[88" claim-type="Currently amended] 88. The method of claim 87,
And the mixing region comprises the hole transport material and the electron transport material in a proportion.
[89" claim-type="Currently amended] 88. The method of claim 87,
And a part of the mixed region is the light emitting region.
[90" claim-type="Currently amended] 88. The method of claim 87,
A light emitting device, wherein a portion of the mixed region is doped with a blocking material, wherein the energy difference between the highest occupied and lowest unoccupied molecular trajectory is large compared to the energy difference in the hole transport material and the electron transport material.
[91" claim-type="Currently amended] 92. The method of claim 90,
And the light emitting area is disposed closer to the anode than the portion to which the blocking material is added.
[92" claim-type="Currently amended] 88. The method of claim 87,
Wherein the light emitting material provides light emission from a triple excited state.
[93" claim-type="Currently amended] 88. The method of claim 87,
Wherein the ratio of the mass of the hole transport material to the total mass of the hole transport material and the electron transport material in the mixing zone is at least 10% and at most 90%.
[94" claim-type="Currently amended] 88. The method of claim 87,
Wherein said mixed region is at least 10 nm and has a thickness of at most 100 nm.
[95" claim-type="Currently amended] 88. The method of claim 87,
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[96" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
cathode,
An electron injection region adjacent the cathode, and
An organic compound layer provided between said electron injection region and said cathode, said organic compound layer comprising a hole transport region comprising a hole transport material and an electron transport region comprising an electron transport material,
A mixing region is provided between the hole transport region and the electron transport region, and includes the hole transport material and the electron transport material,
A light emitting device provided with a light emitting material added to the mixed region.
[97" claim-type="Currently amended] 97. The method of claim 96,
And the mixing region comprises a hole transport material and an electron transport material in a proportion.
[98" claim-type="Currently amended] 97. The method of claim 96,
And a part of the mixed region is the light emitting region.
[99" claim-type="Currently amended] 97. The method of claim 96,
A light emitting device, wherein a portion of the mixed region is doped with a blocking material, wherein the energy difference between the highest occupied and lowest unoccupied molecular trajectory is large compared to the energy difference in the hole transport material and the electron transport material.
[100" claim-type="Currently amended] The method of claim 99, wherein
And the light emitting area is disposed closer to the anode than the portion to which the blocking material is added.
[101" claim-type="Currently amended] 97. The method of claim 96,
Wherein the light emitting material provides light emission from a triple excited state.
[102" claim-type="Currently amended] 97. The method of claim 96,
Wherein the ratio of the mass of the hole transport material to the total mass of the hole transport material and the electron transport material in the mixing zone is at least 10% and at most 90%.
[103" claim-type="Currently amended] 97. The method of claim 96,
Wherein said mixed region is at least 10 nm and has a thickness of at most 100 nm.
[104" claim-type="Currently amended] 97. The method of claim 96,
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[105" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
cathode,
A hole injection region adjacent to the anode,
An electron injection region adjacent the cathode, and
An organic compound layer provided between said electron injection region and said hole injection region, said organic compound layer comprising a hole transport region comprising a hole transport material and an electron transport region comprising an electron transport material,
A mixing region is provided between the hole transport region and the electron transport region, and includes the hole transport material and the electron transport material,
And a light emitting area to which the light emitting material is added to the mixed area.
[106" claim-type="Currently amended] 105. The method of claim 105,
And the mixing region comprises the hole transport material and the electron transport material in a proportion.
[107" claim-type="Currently amended] 105. The method of claim 105,
And a part of the mixed region is the light emitting region.
[108" claim-type="Currently amended] 105. The method of claim 105,
A light emitting device, wherein a portion of the mixed region is doped with a blocking material, wherein the energy difference between the highest occupied and lowest unoccupied molecular trajectory is large compared to the energy difference in the hole transport material and the electron transport material.
[109" claim-type="Currently amended] 109. The method of claim 108,
And the light emitting area is disposed closer to the anode than the portion to which the blocking material is added.
[110" claim-type="Currently amended] 105. The method of claim 105,
Wherein the light emitting material provides light emission from a triple excited state.
[111" claim-type="Currently amended] 105. The method of claim 105,
Wherein the ratio of the mass of the hole transport material to the total mass of the hole transport material and the electron transport material in the mixing zone is at least 10% and at most 90%.
[112" claim-type="Currently amended] 105. The method of claim 105,
Wherein said mixed region is at least 10 nm and has a thickness of at most 100 nm.
[113" claim-type="Currently amended] 105. The method of claim 105,
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[114" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
cathode,
A first mixing region adjacent the anode and comprising a hole injection material and a hole transport material,
A second mixing region adjacent the cathode and comprising an electron injection material and an electron transport material, and
And a third mixed region provided between said first mixed region and said second mixed region, said third mixed region comprising said hole transport material and said electron transport material.
[115" claim-type="Currently amended] 116. The method of claim 114, wherein
And a concentration gradient in which the concentration of the hole transporting material in the first mixed region is reduced from the anode toward the third region and the concentration of the hole injection material is increased from the anode toward the third region.
[116" claim-type="Currently amended] 116. The method of claim 114, wherein
And a concentration gradient in which the concentration of the electron transport material increases from the cathode toward the third region and the concentration of the electron injection material decreases from the cathode toward the third region.
[117" claim-type="Currently amended] 116. The method of claim 114, wherein
A light emitting device having a concentration gradient in which the concentration of the electron transporting material in the third region is reduced from the second region toward the first region and the concentration of the hole transporting material is increased from the second region towards the first region .
[118" claim-type="Currently amended] 116. The method of claim 114, wherein
Wherein the light emitting material is doped in a portion of the third region.
[119" claim-type="Currently amended] 119. The method of claim 118 wherein
Wherein the light emitting material is a triple light emitting diode.
[120" claim-type="Currently amended] 119. The method of claim 118 wherein
The light emitting device is an electronic product selected from the group consisting of a display device, a video camera, a digital camera, an image reproducing device, a portable computer, a personal computer, a mobile phone, and audio.
[121" claim-type="Currently amended] A light emitting device comprising an organic light emitting device,
anode,
cathode,
A first mixing region adjacent the anode and comprising a hole injection material and a hole transport material,
A second mixing region adjacent the first region and comprising a hole transport material and a host material,
A third mixed region adjacent the second mixed region and comprising the host material and a blocking material, and
And a fourth mixed region provided between the third mixed region and the cathode, the fourth mixed region comprising the blocking material and the electron injection material.
[122" claim-type="Currently amended] 128. The method of claim 121, wherein
And a concentration gradient in which the concentration of the hole injection material is reduced from the anode toward the second area and the concentration of the hole transport material is increased from the anode toward the second area in the first area.
[123" claim-type="Currently amended] 128. The method of claim 121, wherein
And a concentration gradient in which the concentration of the hole transport material in the second region is reduced from the first region toward the third region and the concentration of the host material is increased from the first region towards the third region.
[124" claim-type="Currently amended] 128. The method of claim 121, wherein
And a concentration gradient in which the concentration of the host material in the third region is reduced from the second region toward the fourth region and the concentration of the blocking material is increased from the second region toward the fourth region.
[125" claim-type="Currently amended] 128. The method of claim 121, wherein
And a concentration gradient in which the concentration of the blocking material decreases from the third region toward the cathode and in which the concentration of the electron injection material increases from the third region toward the cathode.
[126" claim-type="Currently amended] 128. The method of claim 121, wherein
Wherein a portion of both the second region and the third region is doped with a luminescent material.
[127" claim-type="Currently amended] 127. The method of claim 126, wherein
Wherein the light emitting material is a triple light emitting diode.
[128" claim-type="Currently amended] 128. The method of claim 121, wherein
And the blocking material is an electron transporting material.

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同族专利:

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公开号 | 公开日

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US20090273280A1|2009-11-05|

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KR100863142B1|2008-10-14|

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JP5820350B2|2015-11-24|

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CN1362746A|2002-08-07|

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EP1220340B1|2011-11-16|

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EP2256840A2|2010-12-01|

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CN1255882C|2006-05-10|

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US8310147B2|2012-11-13|

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引用文献:

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公开号 | 申请日 | 公开日 | 申请人 | 专利标题

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法律状态:
2000-12-28|Priority to JP2000400953

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2000-12-28|Priority to JPJP-P-2000-00400953

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2001-01-29|Priority to JPJP-P-2001-00020817

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2001-01-29|Priority to JP2001020817

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2001-02-08|Priority to JP2001032406

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2001-02-08|Priority to JPJP-P-2001-00032406

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2001-12-27|Application filed by 야마자끼 순페이, 가부시키가이샤 한도오따이 에네루기 켄큐쇼

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2002-07-08|Publication of KR20020055416A

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2008-10-14|Application granted

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2008-10-14|Publication of KR100863142B1

优先权:

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申请号 | 申请日 | 专利标题

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JP2000400953|2000-12-28|

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JPJP-P-2000-00400953|2000-12-28|

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JPJP-P-2001-00020817|2001-01-29|

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JP2001020817|2001-01-29|

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JP2001032406|2001-02-08|

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JPJP-P-2001-00032406|2001-02-08|