Light-emitting elements, light-emitting devices, and electronic devices

Abstract

To provide a novel light-emitting element. Or, to provide a light-emitting element with a good lifespan. Or, To provide a light-emitting element with good luminescence efficiency. [Solution] The EL layer is provided between a pair of electrodes, and the EL layer contains at least a fluorescent material and a phosphorescent material. A light-emitting layer containing a light material, a first electron transport layer containing a first electron transport material, and a second electron transport layer A second electron transport layer containing the transport material is provided in contact with the host material in this order, and the second electron transport layer The material provides a light-emitting element whose LUMO level is higher than that of the first electron transport material. ru.

Description

[Technical Field]

[0001] One aspect of the present invention is a light-emitting element, a display module, a lighting module, a display device, This invention relates to optical devices, electronic devices, and lighting devices. One aspect of the present invention is not limited to the above-mentioned technical field. Not specified. The technical field of one aspect of the invention disclosed herein, etc., relates to a product, method, or manufacturing. This relates to a method. Alternatively, one aspect of the present invention relates to a process, machine, or manufacture. This relates to tea, or composition of matter. More specifically, the technical field of one aspect of the present invention disclosed herein includes semiconductor devices, and Display devices, liquid crystal display devices, light-emitting devices, lighting devices, energy storage devices, memory devices, imaging devices, and their Driving methods, or methods for manufacturing them, can be given as examples. [Background technology]

[0002] Electroluminescence (EL) using organic compounds The practical application of light-emitting elements (organic EL elements) that utilize luminescence is progressing. The basic structure of this device consists of an organic compound layer (EL layer) containing a light-emitting material sandwiched between a pair of electrodes. Therefore, by applying a voltage to this element, light emission can be obtained from the light-emitting material. ru.

[0003] Because such light-emitting elements are self-emissive, when used as pixels in a display, they result in a liquid crystal display. Compared to flat panel displays, they offer advantages such as higher visibility and the elimination of the need for a backlight. It is suitable as a ray element. Furthermore, displays using such light-emitting elements are thin and light The ability to mass-produce them is a major advantage. Furthermore, their extremely fast response speed is another notable feature. are provided.

[0004] Furthermore, since these light-emitting elements can have a light-emitting layer formed continuously in two dimensions, planar light emission can be obtained. This is a feature that is difficult to achieve with point light sources typified by incandescent bulbs and LEDs, or linear light sources typified by fluorescent lamps; therefore, the light-emitting element has high utility value as a planar light source applicable to lighting and the like. .

[0005] As described above, displays and lighting devices using light-emitting elements are suitable for application to various electronic devices. However, research and development are ongoing to develop light-emitting elements with better efficiency and longer lifespan.

[0006] Patent Document 1 discloses a light-emitting element that achieves a longer lifespan by using an electron-transporting layer added with a substance having an electron-trapping property. . [Prior Art Document] [Patent Document]

[0007] [Patent Document 1] Japanese Unexamined Patent Publication No. 2009-177157 [Summary of the Invention] [Problem to be Solved by the Invention]

[0008] An object of one aspect of the present invention is to provide a novel light-emitting element. Alternatively, it is an object to provide a light-emitting element with a good lifespan. Alternatively, it is an object to provide a light-emitting element with good luminous efficiency. .[ ]

[0009] Alternatively, another object of another aspect of the present invention is to each provide a highly reliable light-emitting device, electronic device, and display device. Alternatively, another aspect of the present invention aims to provide a light-emitting device with low power consumption. The purpose is to provide a device, electronic equipment, and display device, respectively.

[0010] The present invention only needs to solve one of the above-mentioned problems. [Means for solving the problem]

[0011] A light-emitting element according to one aspect of the present invention comprises an anode, a cathode, and an E sandwiched between the anode and the cathode. The L layer has an EL layer, and the EL layer has a light-emitting layer, a first electron transport layer, and a second electron transport layer. The first electron transport layer is provided between the light-emitting layer and the second electron transport layer, and the The optical layer has a region in contact with the first electron transport layer, and the second electron transport layer is in contact with the first electron The light-emitting layer has a region in contact with the transport layer, and the light-emitting layer has a fluorescent light-emitting substance and a host material, The first electron transport layer has a first material, and the second electron transport layer has a second material, The LUMO level of the host material is higher than the LUMO level of the first material, and the second material The LUMO level of the first material is higher than the LUMO level of the first material, and the host material has 3 or more rings. A substance containing a condensed aromatic ring skeleton with 6 or fewer rings, wherein the first material is a first heteroatomolecular ring skeleton The substance contains, and the second material is a substance containing a second heteroaromatic ring skeleton, and the first The substance containing the first heteroaromatic ring skeleton and the substance containing the second heteroaromatic ring skeleton are different substances. It is a light-emitting element.

[0012] Furthermore, another configuration of the present invention is a light-emitting element having the above configuration, wherein the first heteroaromatic ring A substance having a skeleton and a substance having a second heteroaromatic ring skeleton, a 6-membered ring nitrogen-containing heteroaromatic ring It is a light-emitting element that is made of a material that includes a framework.

[0013] Furthermore, another configuration of the present invention is a light-emitting element having the above configuration, wherein the first heteroaromatic ring The light-emitting element is a material containing a condensed heteroaromatic ring skeleton.

[0014] Furthermore, another configuration of the present invention is a light-emitting element having the above configuration, wherein the first heteroaromatic ring A substance containing a skeleton contains a condensed heteroaromatic ring skeleton having a diazine skeleton or a triazine skeleton. It is a light-emitting element, which is a physical substance.

[0015] Furthermore, another configuration of the present invention is a light-emitting element having the above configuration, wherein the first heteroaromatic ring The light-emitting element is a material containing a skeleton, which has a pyrazine skeleton or a pyrimidine skeleton. .

[0016] Furthermore, another configuration of the present invention is a light-emitting element having the above configuration, wherein the first heteroaromatic ring The light-emitting element is a material containing a skeleton, specifically a material having a dibenzoquinoxaline skeleton.

[0017] Alternatively, another aspect of the present invention relates to a light-emitting element having the above configuration, wherein the host material This is a light-emitting element made of a material containing an anthracene skeleton.

[0018] Alternatively, in another aspect of the present invention, in a light-emitting element having the above configuration, the aforementioned second electron The transport layer is a light-emitting element in which the cathode is in contact.

[0019] Alternatively, in another aspect of the present invention, in a light-emitting element having the above configuration, the EL layer is Furthermore, it has a hole injection layer, the hole injection layer is in contact with the anode, and the hole injection layer is an organic agent This is a light-emitting element containing a septa material.

[0020] Alternatively, in another aspect of the present invention, in a light-emitting element having the above configuration, the organic accessory The puta material is 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexacyano This is a light-emitting element made of xaazatriphenylene.

[0021] Alternatively, in another aspect of the present invention, a light-emitting element having the above configuration, wherein the fluorescent light-emitting material It is a light-emitting element that emits blue light.

[0022] Alternatively, another aspect of the present invention provides a light-emitting element having the above configuration, and a transistor, or It is a light-emitting device having a substrate and a light-emitting device.

[0023] Alternatively, another aspect of the present invention provides a light-emitting device having the above configuration, a sensor, an operating button, It is an electronic device having a speaker or a microphone.

[0024] Alternatively, another aspect of the present invention is a lighting device having the above configuration, and a housing, It is a device.

[0025] In this specification, the term "light-emitting device" includes image display devices that use light-emitting elements. Furthermore, a connector can be attached to the light-emitting element, for example, an anisotropic conductive film or TCP (Tape Carrier). A module with an aftermarket package attached, and a printed circuit board beyond the TCP. The installed module or light-emitting element uses the COG (Chip On Glass) method. Modules on which ICs (integrated circuits) are directly mounted may have light-emitting devices. Furthermore, lighting fixtures and the like may have light-emitting devices. [Effects of the Invention]

[0026] In one aspect of the present invention, a novel light-emitting element can be provided, or a light-emitting element with a good lifespan can be provided. It is possible to provide an optical element. Or, it is possible to provide a light-emitting element with good luminescence efficiency. Cut.

[0027] Alternatively, in another aspect of the present invention, a highly reliable light-emitting device, electronic device, and display device are provided, respectively. It can be provided. Or, in another aspect of the present invention, a light-emitting device with low power consumption, Electronic devices and display devices can be provided, respectively.

[0028] Furthermore, the description of these effects does not preclude the existence of other effects. The embodiment does not necessarily have to have all of these effects. Furthermore, other effects are... This will become clear from the description in the specification, drawings, claims, etc., and the specification, drawings Furthermore, it is possible to extract other effects from the descriptions in the claims and other documents. [Brief explanation of the drawing]

[0029] [Figure 1] Schematic diagram of a light-emitting element. [Figure 2] Conceptual diagram of an active matrix light-emitting device. [Figure 3] Conceptual diagram of an active matrix light-emitting device. [Figure 4] Conceptual diagram of an active matrix light-emitting device. [Figure 5] Conceptual diagram of a passive matrix type light-emitting device. [Figure 6] A diagram representing a lighting device. [Figure 7] A diagram representing electronic devices. [Figure 8] A diagram representing a light source device. [Figure 9] A diagram representing a lighting device. [Figure 10] A diagram representing a lighting device. [Figure 11] A diagram showing an in-vehicle display device and lighting system. [Figure 12] A diagram representing electronic devices. [Figure 13] A diagram representing electronic devices. [Figure 14] Brightness-current density characteristics of light-emitting element 1 and comparison light-emitting element 1. [Figure 15] Current efficiency-luminance characteristics of light-emitting element 1 and comparative light-emitting element 1. [Figure 16] Brightness-voltage characteristics of light-emitting element 1 and comparison light-emitting element 1. [Figure 17] Current-voltage characteristics of light-emitting element 1 and comparison light-emitting element 1. [Figure 18] External quantum efficiency-luminance characteristics of light-emitting element 1 and comparative light-emitting element 1. [Figure 19] Emission spectra of light-emitting element 1 and comparative light-emitting element 1. [Figure 20] Normalized luminance-time variation characteristics of light-emitting element 1 and comparative light-emitting element 1. [Figure 21] Brightness-current density characteristics of light-emitting element 2 and comparative light-emitting element 2. [Figure 22] Current efficiency-luminance characteristics of light-emitting element 2 and comparative light-emitting element 2. [Figure 23] Brightness-voltage characteristics of light-emitting element 2 and comparison light-emitting element 2. [Figure 24] Current-voltage characteristics of light-emitting element 2 and comparison light-emitting element 2. [Figure 25] External quantum efficiency-luminance characteristics of light-emitting element 2 and comparative light-emitting element 2. [Figure 26] Emission spectra of light-emitting element 2 and comparison light-emitting element 2. [Figure 27] Normalized luminance-time variation characteristics of light-emitting element 2 and comparative light-emitting element 2. [Figure 28] Brightness-current density characteristics of light-emitting element 3 and comparative light-emitting element 3. [Figure 29] Current efficiency-luminance characteristics of light-emitting element 3 and comparative light-emitting element 3. [Figure 30] Brightness-voltage characteristics of light-emitting element 3 and comparison light-emitting element 3. [Figure 31] Current-voltage characteristics of light-emitting element 3 and comparison light-emitting element 3. [Figure 32] External quantum efficiency-luminance characteristics of light-emitting element 3 and comparative light-emitting element 3. [Figure 33] Emission spectra of light-emitting element 3 and comparison light-emitting element 3. [Figure 34] Normalized brightness-time variation characteristics of light-emitting element 3 and comparative light-emitting element 3. [Figure 35] Brightness-current density characteristics of light-emitting element 4 and comparison light-emitting element 4. [Figure 36] Current efficiency-luminance characteristics of light-emitting element 4 and comparative light-emitting element 4. [Figure 37] Brightness-voltage characteristics of light-emitting element 4 and comparison light-emitting element 4. [Figure 38] Current-voltage characteristics of light-emitting element 4 and comparison light-emitting element 4. [Figure 39] External quantum efficiency-luminance characteristics of light-emitting element 4 and comparative light-emitting element 4. [Figure 40] Emission spectra of light-emitting element 4 and comparison light-emitting element 4. [Figure 41] Normalized brightness-time variation characteristics of light-emitting element 4 and comparative light-emitting element 4. [Modes for carrying out the invention]

[0030] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is as follows The description is not limited to the present invention, and the form and details may not depart from the spirit and scope of the present invention. Those skilled in the art will readily understand that the parameters can be modified in various ways. Therefore, the present invention is described below. This should not be interpreted as being limited to the contents described in the embodiment.

[0031] (Embodiment 1) Figure 1(A) is a diagram showing a light-emitting element according to one embodiment of the present invention. The light-emitting element according to one embodiment of the present invention is It has at least an anode 101, a cathode 102, and an EL layer 103. 3 comprises at least an emissive layer 113, a first electron transport layer 114-1 and a second electron transport layer 11 It has 4-2.

[0032] The light-emitting layer 113 includes a host material and a fluorescent light-emitting substance, and when a voltage is applied to the light-emitting element, By flowing a stream of light, it is possible to obtain light from a fluorescent material.

[0033] Furthermore, the host material is a substance containing a condensed aromatic ring skeleton with 3 to 6 rings, and the first electric The material constituting the electron transport layer 114-1 and the material constituting the second electron transport layer 114-2 are multiple It is a substance containing an aromatic ring skeleton. Furthermore, the material constituting the first electron transport layer 114-1 is the same as the second The materials constituting the electron transport layer 114-2 of unit 2 are assumed to be different substances.

[0034] In this embodiment of the present invention, a light-emitting element comprises a host material and a second electron transport layer 114-2 The LUMO levels of both materials constituting the first electron transport layer 114-1 are the same as those of the materials constituting the first electron transport layer 114-1. It is characterized by being at a level higher (shallower) than the LUMO level of the host material. The difference in LUMO levels between the material constituting the first electron transport layer 114-1 and the other material is within 0.3 eV. It is preferable to have this. If it is within 0.3eV, the rise in drive voltage can be suppressed.

[0035] Typically, when designing light-emitting elements, the goal is to reduce the carrier injection barrier between each layer and drive the energy. To reduce pressure and improve lifespan, the electron transport layer is processed in order from the cathode layer, using LUM The design is such that the O level becomes higher (shallower).

[0036] However, in one aspect of the present invention, the light-emitting element is composed of a host material and an electron transport layer. By setting the MO levels to the relationship described above and using materials with specific skeletons, This makes it possible to provide a light-emitting element with a better lifespan than conventional light-emitting elements.

[0037] The host material is preferably a material having a condensed aromatic ring skeleton with 3 to 6 rings. The condensed aromatic ring maintains electrochemical stability while preserving an energy gap near the visible light region. Because it can be secured. In particular, the anthracene skeleton excites blue fluorescent materials. A sufficient energy gap can be obtained, and both holes and electrons can be transported, therefore, It is suitable. Furthermore, anthracene derivatives can have their LUMO level set to around -2.7 eV. This is easy and also suitable for constructing the LUMO level relationships described above.

[0038] On the other hand, the material constituting the first electron transport layer 114-1 and the material constituting the second electron transport layer 114-2 The materials used are preferably materials containing different hetero-aromatic ring skeletons. Complex aromatic ring bone material used in electron transport layer 114-1 and electron transport layer 214-2 By varying the grade, the LUMO levels of the materials constituting the first electron transport layer 114-1 are changed. This is lower than the LUMO level of the host material and the material constituting the second electron transport layer 114-2. This makes it possible to place it in a deeper position.

[0039] Furthermore, the EL layer 103 has a hole injection layer 111, and the hole injection layer 111 is composed of When organic acceptor materials are used as the material, not only can the lifespan be extended compared to conventional methods, This reduces the efficiency degradation in the high-brightness region, also known as the roll-off phenomenon, and enables high-brightness and high-efficiency light-emitting elements. This makes it possible to achieve this. Therefore, in one aspect of the present invention, the EL layer 103 is further positive The facility has a hole injection layer 111, and the material constituting the hole injection layer 111 is an organic acceptor material. I used it.

[0040] One reason for this is that the problem of low hole injection ability of organic acceptors is addressed by the structure described above. This is thought to be because the components are complemented. Many organic acceptors have a HOMO level of -5. For materials with HOMO levels lower (deeper) than 4eV, the acceptability becomes weaker. In other words, hole injection becomes more difficult. Therefore, when using organic acceptors in the hole injection layer... It is preferable to use a material with a HOMO level of -5.4 eV or higher in the hole transport layer, On the other hand, it becomes difficult to inject holes from such a hole transport layer into the light-emitting layer. This is because 3 The HOMO level of materials having a condensed aromatic ring skeleton with 6 to 6 rings is lower than -5.4 eV. This is because the holes are often deep. Thus, when organic acceptors are used in the hole injection layer... In addition, there is an obstacle to ultimately injecting holes into the light-emitting layer, resulting in a low hole injection capacity. cormorant.

[0041] As a result, for example, if the first electron transport layer 114-1 is not provided, or if the host material or the A material having the same LUMO level as the material constituting the electron transport layer 114-2 of the first electron transport layer When used in the electron transport layer 114-1, the organic acceptor is used in comparison to its electron injection and transport properties. Because the hole injection and transport properties of the hole injection layer used are reduced, especially on the high-brightness side. This results in an electron-excess element, causing roll-off. In this case, the carrier The recombination region becomes narrower, negatively impacting the lifetime. However, the host material and the first electron transport... The LU of the material constituting layer 114-1 and the material constituting the second electron transport layer 114-2 By constructing the MO level as described above, a hole-injection layer using an organic acceptor is introduced. Even if it enters the region, it can maintain carrier balance in the high-brightness area, thus emitting an effective light. This can increase the rate. Furthermore, it allows for a wider carrier recombination area, thus increasing lifespan. It can be made to live. Organic acceptors have the advantage of good sublimation properties, while hole injection ability There was a problem with low performance, but this problem can be solved by one form of the present invention.

[0042] Furthermore, depending on the structure, it may be possible to improve not only the lifespan but also the luminous efficiency. For example, the hole injection layer 111 contains a material having hole transport properties and a material having acceptor properties. Materials (for example, acceptor-type transition metal oxides, particularly those in Group 4 to Group 4 of the periodic table) When using composite materials containing oxides of metals belonging to Group 8, not only in the high-brightness region, This makes it possible to obtain light-emitting elements with very high efficiency across almost all brightness ranges.

[0043] Next, we will describe the detailed structure and material examples of the light-emitting element described above. As described above, the light-emitting element consists of multiple layers between a pair of electrodes, an anode 101 and a cathode 102. It has an L layer 103, and the EL layer 103 consists of at least an emissive layer 113 and a first electron transport layer 11 It includes 4-1 and the second electron transport layer 114-2. Also, these light-emitting layers 113 and the first electron The transport layer 114-1 and the second electron transport layer 114-2 are arranged in this order in contact with each other.

[0044] There are no particular limitations on the other layers included in the EL layer 103, including hole injection layers and hole injection layers. Various layers such as electron injection layers, carrier blocking layers, exciton blocking layers, and charge generation layers. The structure can be applied.

[0045] Anode 101 is a metal, alloy, or conductive material with a high work function (specifically, 4.0 eV or higher). It is preferable to form them using compounds and mixtures thereof. Specifically, for example, Indium tin oxide (ITO), silicon Alternatively, indium oxide-tin oxide, indium oxide-zinc oxide, and acid containing silicon oxide. Examples include indium oxide (IWZO) containing tungsten oxide and zinc oxide. These conductive metal oxide films are usually deposited by sputtering, but the sol-gel method... It is also acceptable to manufacture it by applying the following methods. An example of a manufacturing method is indium oxide-zinc oxide. This involves using a target to which 1-20 wt% zinc oxide has been added to indium oxide. Methods for forming it include the taring method. It also contains tungsten oxide and zinc oxide. Indium oxide (IWZO) is obtained by adding tungsten oxide to indium oxide at a ratio of 0.5 to 0.5. Using a target containing 5 wt% zinc oxide and 0.1-1 wt% zinc oxide, the sputtering method is applied. It can also be formed from gold (Au), platinum (Pt), nickel (Ni), and t Calcium (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co ), copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g., titanium nitride) Examples include graphene. Furthermore, the composite material described later can be used for the EL layer 1. By using it in the layer in contact with the anode 101 in 03, the electrode material can be selected regardless of the work function. You will be able to choose.

[0046] Regarding the laminated structure of the EL layer 103, in this embodiment, as shown in Figure 1(A), Hole injection layer 111, hole transport layer 112, light-emitting layer 113, first electron transport layer 114-1, second The configuration includes an electron transport layer 114-2 and an electron injection layer 115, as shown in Figure 1(B). , hole injection layer 111, hole transport layer 112, light emission layer 113, first electron transport layer 114-1, This section describes two types of configurations, one having a second electron transport layer 114-2 and a charge generation layer 116. To clarify, the materials that make up each layer are specifically described below.

[0047] The hole injection layer 111 is a layer containing a material that has hole injection properties. Transition metal oxides, in particular Oxides of metals belonging to groups 4 through 8 of the periodic table (for example, molybdenum oxide and Vanadium oxide, ruthenium oxide, rhenium oxide, tungsten oxide, manganese Oxides, etc., can be used. Also, complexes of transition metals, especially those of the fourth element in the periodic table, can be used. Complexes of metals belonging to groups 1 through 8 can also be used, for example, molybdenum tris[1,2 -Bis(trifluoromethyl)ethane-1,2-dithiolene](abbreviation: Mo(tfd)3 Examples include molybdenum complexes such as those shown above. These transition metal oxides, especially those in the periodic table, are examples of molybdenum complexes. Oxides of metals belonging to groups 4 through 8, complexes of transition metals, and especially in the periodic table. Complexes of metals belonging to groups 4 through 8 act as acceptors. Acceptors are positive From the hole transport layer (or hole transport material) adjacent to the hole injection layer 111, at least the electric field Electrons can be extracted by applying an applied force. Furthermore, 7,7,8,8-tetracyano-2, 3,5,6-Tetrafluoroquinodimethane (abbreviation: F4-TCNQ), 3,6-Difluoro Ro-2,5,7,7,8,8-Hexacyanoquinodimethane, Chloranil, 2,3,6,7 ,10,11-Hexacyano-1,4,5,8,9,12-Hexazatriphenylene( Compounds having electron-withdrawing groups (halogen groups or cyano groups), such as (abbreviated as HAT-CN), are used. This is possible. Compounds having the above-mentioned electron-withdrawing groups (halogen groups or cyano groups) are organic accessories. It acts as an acceptor. The organic acceptor is adjacent to the hole transport layer (a hole injection layer 111). Electrons can be extracted from hole transport materials by applying at least an electric field. In addition, phthalocyanines such as phthalocyanine (abbreviated as H2Pc) and copper phthalocyanine (CuPc) Anine compounds, 4,4'-bis[N-(4-diphenylaminophenyl)-N-fe [Nylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methyl phenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4 Aromatic amine compounds such as ,4'-diamine (abbreviation: DNTPD), or poly(3,4- Ethylenedioxythiophene / poly(styrene sulfonic acid) (PEDOT / PSS), etc. The hole injection layer 111 can also be formed by polymers or the like.

[0048] Furthermore, the hole injection layer 111 is a composite material containing a hole transporting substance and an acceptor substance. Composite materials can be used. Furthermore, a hole-transporting substance may contain an acceptor substance. By using this method, it is possible to select the material for forming the electrodes regardless of the work function of the electrodes. In other words, not only materials with a high work function as anode 101, but also materials with a low work function It will also be possible to use it. Acceptable substances include F4-TCNQ and chlora Compounds having electron-withdrawing groups (halogen groups or cyano groups) such as nyl and HAT-CN, and transition gold Examples include group oxides, particularly oxides of metals belonging to groups 4 through 8 of the periodic table. This is possible. Transition metal oxides, especially metals belonging to groups 4 through 8 of the periodic table. The oxides also act on hole-transporting materials with a HOMO lower (deeper) than -5.4 eV. It exhibits scepter properties (at least electrons can be extracted by applying an electric field), therefore it is suitable. That is the case.

[0049] Compounds having the above-mentioned electron-withdrawing groups (halogen groups or cyano groups) include, in particular, HAT-CN Compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple complex atoms, such as the one shown, are thermally It is stable and desirable.

[0050] Transition metal oxides are oxides of metals belonging to groups 4 through 8 of the periodic table. Vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tan oxide Gusten, manganese oxide, and rhenium oxide are preferred due to their high acceptability. Molybdenum oxide is preferable because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle.

[0051] Examples of hole-transporting substances used in composite materials include aromatic amine compounds and carbazole derivatives. Body, aromatic hydrocarbons, polymer compounds (oligomers, dendrimers, polymers, etc.), species Various organic compounds can be used. Note that the organic compounds used in the composite material are... It is preferable that the organic compound has high pore transport properties. Specifically, 10 -6 cm 2 / Vs or later It is preferable that the material has the above hole mobility. Below, hole transport in composite materials Here are some specific examples of organic compounds that can be used as transportable substances.

[0052] Aromatic amine compounds include N,N'-di(p-tolyl)-N,N'-diphenyl- p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenyl [N-phenylamino]biphenyl (abbreviation: DPAB), N,N'- Bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl- (1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), 1,3,5- RIS[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: Examples include DPA3B).

[0053] Examples of carbazole derivatives include 3-[N-(9-phenylcarbazole-3-yl)-N -phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-phenylamino] Su[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenyl Lucarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-fu Phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzP) Examples include CN1). In addition, there is 4,4'-di(N-carbazolyl)biph Phenyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]be Nzen (abbreviation: TCPB), 9-[4-(10-phenyl-9-antryl)phenyl] -9H-carbazole (abbreviation: CzPA), 1,4-bis[4-(N-carbazolyl)f [phenyl]-2,3,5,6-tetraphenylbenzene, etc., can be used.

[0054] Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl). ) Anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1- Naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (Abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl) Anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene ( Abbreviations: DNA), 9,10-diphenylanthracene (abbreviations: DPAnth), 2-te rt-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl- 1-Naphthyl)anthracene (abbreviation: DMNA), 2-tert-butyl-9,10-butyl Su[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl] Phenyl anthracene, 2,3,6,7-tetramethyl-9,10-di(1-naph (Tyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl) Ntracene, 9,9'-biantryl, 10,10'-diphenyl-9,9'-biant Lil, 10,10'-bis(2-phenylphenyl)-9,9'-biantrill, 10, 10'-Bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bian Trill, anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra( Examples include tert-butyl)perylene. In addition, pentacene, coronene, etc. It can be used in this way. -6 cm 2 Having a hole mobility of / Vs or greater, It is more preferable to use aromatic hydrocarbons having 14 to 42 carbon atoms. Hydrogen may have a vinyl skeleton. As an aromatic hydrocarbon having a vinyl group For example, 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVB) i) 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviated) Examples include DPVPA.

[0055] Also, poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyltriphen Nylamine (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenyl [amino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide]( Abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis High molecular weight compounds such as (phenyl)benzidine (abbreviated as Poly-TPD) can also be used. can.

[0056] By forming a hole injection layer, hole injection performance is improved, and a low driving voltage is required. Optical elements can be obtained.

[0057] The hole transport layer 112 is a layer containing a hole-transporting substance. The hole-transporting substance is: For example, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated) Name: NPB) or N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1, 1'-Biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4',4''-Tris (N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4 Tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (Abbreviation: MTDATA), 4,4'-bis[N-(spiro-9,9'-bifluorene-2) -yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4'- (9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), etc. Aromatic amine compounds and the like can be used. The substances described herein have high hole transport properties. , mainly 10 -6 cm 2It is a material having a hole mobility of / Vs or greater. Also, the above-mentioned composite material The organic compounds listed as hole-transporting substances in the material can also be used in the hole transport layer 112. Yes, it is possible. Also, poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyl carbazole) High molecular weight compounds such as riphenylamine (PVTPA) can also be used. The layer containing the hole-transporting material is not limited to a single layer, but may consist of two or more layers made of the above material. It may also be made into a stacked structure.

[0058] Even if the light-emitting layer 113 is a layer that contains a fluorescent light-emitting material and exhibits fluorescent emission, it may also contain a phosphorescent material. A layer containing a substance that exhibits fluorescence emission, and a substance containing a substance that exhibits thermally activated delayed fluorescence (TADF) Any of the layers exhibiting this characteristic is acceptable. Furthermore, even a single layer can contain different luminescent materials. It may consist of multiple layers. In one aspect of the present invention, a layer exhibiting fluorescence emission, In particular, it is preferable that the layer exhibits blue fluorescence emission.

[0059] In the light-emitting layer 113, possible materials that can be used as fluorescent light-emitting materials include, for example, Examples include the following. Other fluorescent materials can also be used.

[0060] 5,6-Bis[4-(10-phenyl-9-antryl)phenyl]-2,2'-bipyri Zin (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-antri [Lu)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N, N'-Bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-N,N' -Diphenyl-pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'- Bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene] -9-yl)phenyl]-pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAP) rn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N' -Diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-Cal Bazole-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (Abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-di Phenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-di Phenyl-N-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazo 3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-ter t-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4' -(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCB) APA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4) ,1-phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine ] (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl- 2-Anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA) ), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N' -Triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N' ,N',N'',N'',N''',N'''-Octaphenyldibenzo[g,p]cri Sen-2,7,10,15-tetraamine (abbreviation: DBC1), coumarin 30, N-(9 ,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3 -amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2- [Iyl)-2-anthryl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviated) Name: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N', N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9, 10-Bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,N',N'- Triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bi Su(1,1'-biphenyl-2-yl)-N-[4-(9H-carbazole-9-yl) Phenyl]-N-phenylanthracene-2-amine (abbreviation: 2YGABPhA), N, N,9-Triphenylanthracene-9-amine (abbreviation: DPhAPhA) Coumarin 54 5T, N,N'-diphenylquinacridone, (abbreviation: DPQd), rubrene, 5,12- Bis(1,1'-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: B) PT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl -4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-Me Chill-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinori [Zin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation) :DCM2), N,N,N',N'-Tetrakis(4-methylphenyl)tetracene-5 ,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N '-Tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluorantene-3, 10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1 ,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[i j]Quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinite Lil (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7 -Tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolidi [-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]ethenyl }-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{ 2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7- Tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl]-4H- Examples include pyran-4-ylidene propanedinitrile (abbreviation: BisDCJTM). In particular, pyrethroids such as 1,6FLPAPrn and 1,6mMemFLPAPrn Condensed aromatic diamine compounds, such as those represented by ¹¹ compounds, have high hole-trapping properties and high luminescence efficiency. It is preferable because it is highly reliable.

[0061] Examples of materials that can be used as phosphorescent materials in the light-emitting layer 113 include, for example, The following are some examples.

[0062] Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H -1,2,4-triazole-3-yl-κN2]phenyl-κC}iridium(III ) (abbreviation: [Ir(mpptz-dmp)3]), Tris(5-methyl-3,4-diphen) Iridium(III) (abbreviation: [Ir(Mpt) z)3]), Tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H -1,2,4-Triazolat] Iridium(III) (Abbreviation: [Ir(iPrptz-3 Organometallic iridium complexes having a 4H-triazole skeleton, such as b)3]), and Tris [3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-tria Zolato] Iridium (III) (abbreviation: [Ir(Mptz1-mp)3]), Tris (1 -Methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium (III) (abbreviation: [Ir(Prptz1-Me)3]) 1H-triazole bone iridium organometallic complexes with a specific classification, and fac-tris[(1-2,6-diisopropyl [Phenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir (iPrpmi)3]), Tris[3-(2,6-dimethylphenyl)-7-methylimi Dazo[1,2-f]phenantriginato]iridium(III) (abbreviation: [Ir(dmp Organometallic iridium complexes having an imidazole skeleton such as impt-Me)3]), Bis[2-(4',6'-difluorophenyl)pyridinate-N,C 2’ ]iridium( III) Tetrakis(1-pyrazolyl)borate (abbreviation: Fir6), bis[2-(4' ,6'-Difluorophenyl)pyridinate-N,C 2’ Iridium(III) picolina Firpic (abbreviation: Firpic), bis{2-[3',5'-bis(trifluoromethyl) [enyl]pyridinate-N,C2’} Iridium (III) picolinate (abbreviation: Ir( CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyri dinate-N,C 2’ iridium (III) acetylacetonate (abbreviation: FIraca c) include organometallic iridium um complexes that use, as a ligand, a phenylpyridine derivative having an electron-withdrawing group. These are compounds that exhibit blue phosphorescence emission, and from 440 nm they are compounds having an emission peak at 520 nm.

[0063] Further, tris(4-methyl-6-phenylpyrimidinato)iridium (III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)iri dium (III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis (6-methyl-4-phenylpyrimidinato)iridium (III) (abbreviation: [Ir(mp pm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4- phenylpyrimidinato)iridium (III) (abbreviation: [Ir(tBuppm)2(ac ac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpy rimidinato]iridium (III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenyl pyrimidinato]iridium (III) (abbreviation: [Ir(mpmppm)2(acac)]] ), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium (II I) (abbreviation: [Ir(dppm)2(acac)]) which are organic compounds having a pyrimidine skeleton iridium metal complexes and (acetylacetonato)bis(3,5-dimethyl-2-phenyl Iridium(III) (abbreviation: Ir(mppr-Me)2(acac)) ]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyra) Dinato-iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]) organometallic iridium complexes having a pyrazine skeleton, such as tris(2-phenylpyridium Nato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(ppy)3]), bis(2- Phenylpyridinato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinate) iridium (I II) Acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), Tris(be Iridium (III) (abbreviation: [Ir(bzq)3]), Tris (2-phenylquinolinato-N,C 2’ Iridium(III) (abbreviation: [Ir(pq) 3]), bis(2-phenylquinolinato-N,C 2’ Iridium(III) acetylated Setanate (abbreviation: [Ir(pq)2(acac)]) is a pyridine skeleton-containing substance In addition to iridium metal complexes, tris(acetylacetonate)(monophenanthroline) Rare earth metals such as rubium(III) (abbreviation: [Tb(acac)3(Phen)]) Examples include complexes. These are compounds that mainly exhibit green phosphorescence, with a wavelength of 500 nm to 6 It has an emission peak at 00 nm. Furthermore, it is an organometallic iridium complex with a pyrimidine skeleton. The body is particularly preferable because it is outstanding in terms of reliability and luminescence efficiency.

[0064] Also, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrim [Dinato] Iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), Su[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)yl Dium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di (Naphthalene-1-yl)pyrimidinato](Dipivaloylmethanato) Iridium (III) Organic compounds having a pyrimidine skeleton, such as (abbreviation: [Ir(d1npm)2(dpm)]) Metallic iridium complexes, and (acetylacetonato)bis(2,3,5-triphenylpyridine Nat(tppr)Iridium(III) (abbreviation: [Ir(tppr)2(acac)]), Bis(2 ,3,5-triphenylpyrazinate)(dipivaloylmethanato)iridium(III)( Abbreviation: [Ir(tppr)2(dpm])]), (acetylacetonato)bis[2,3- Bis(4-fluorophenyl)quinoxalinato] Iridium(III) (abbreviation: [Ir( Organometallic iridium complexes having a pyrazine skeleton such as Fdpq)2(acac)]) and Tris(1-phenylisoquinolinato-N,C) 2’ ) Iridium(III) (abbreviation: [ Ir(piq)3]), bis(1-phenylisoquinolinato-N,C) 2’ )iridium( III) Acetylacetonate (abbreviation: [Ir(piq)2(acac)]) In addition to organometallic iridium complexes with a lysine skeleton, 2, 3, 7, 8, 12, 13, 17, 18-Octaethyl-21H,23H-Porphyrin Platinum(II) (Abbreviation: PtOEP) Platinum complexes such as tris(1,3-diphenyl-1,3-propanedionato)(mono Phenanthroline europium(III) (abbreviation: [Eu(DBM)3(Phen)]) ), Tris[1-(2-tenoyl)-3,3,3-trifluoroacetonate](monophenate) Nanthroline europium(III) (abbreviation: [Eu(TTA)3(Phen)]) Examples of rare earth metal complexes include the following. These are compounds that exhibit red phosphorescence, It has an emission peak between 600 nm and 700 nm. It also has an organogold skeleton. Iridium complexes of this genus produce a red emission with good chromaticity.

[0065] Furthermore, in addition to the phosphorescent compounds described above, known phosphorescent light-emitting materials can also be selected and used. good.

[0066] TADF materials include fullerenes and their derivatives, and acridine derivatives such as proflavin. Eosin and other substances can be used. Magnesium (Mg), zinc (Zn), cadmium Um (Cd), tin (Sn), platinum (Pt), indium (In), or palladium Metal-containing porphyrins including (Pd), etc. can also be used. For example, the protoporphyrin-tin fluoride complex (S) shown in the following structural formula is an example. nF2(Proto IX)), Mesoporphyrin-Tin Fluoride Complex (SnF2(Mes o IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX) ), Coproporphyrin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4Me)), Octaethylporphyrin-tin fluoride complex (SnF2(OEP )), Ethioporphyrin-tin fluoride complex (SnF2(Etio I)), Octaeth Luporphyrin-platinum chloride complex (PtCl2OEP) is another example.

[0067] [ka]

[0068] Furthermore, the following structural formula shows 2-biphenyl-4,6-bis(12-phenylindrose [2,3-a]carbazole-11-yl)-1,3,5-triazine(PIC-TRZ Heterocyclic compounds having π-electron-rich heteroaromatic rings and π-electron-deficient heteroaromatic rings, such as ) are also used. This is possible. The heterocyclic compound is a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring. Because it has a ring, it has high electron transport and hole transport properties, which is preferable. Substances in which an aromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded are the same as those of a π-electron-rich heteroaromatic ring. Both the nar properties and the acceptor properties of the π-electron-deficient complex aromatic ring become stronger, and the S1 and T1 levels This is particularly preferable because it reduces the energy difference.

[0069] [ka]

[0070] Next, various carrier transport materials can be used as the host material for the light-emitting layer. Examples of such carrier transport materials include substances with hole transport properties, such as those shown below, and electric Substances with molecular transport properties can be used. Of course, other substances besides those listed below can also be used. Materials with pore transport properties, electron transport properties, and bipolar properties are also used. It is possible.

[0071] Examples of materials with hole transport properties include 4,4'-bis[N-(1-naphthyl)-N-fe [Nylamino]biphenyl (abbreviation: NPB), N,N'-bis(3-methylphenyl)-N ,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TPD) ,4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenyl [Amino]biphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluorene) 4-phenyl-3'-(9-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9 -phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4- Phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (Abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H- Luvazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-na Phthyl)-4'-(9-phenyl-9H-carbazole-3-yl)-triphenylamine n (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl- 9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9- Dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl) Phenyl]-fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4- (9-phenyl-9H-carbazole-3-yl)phenyl]-spiro-9,9'-bif Compounds having an aromatic amine skeleton such as ruolen-2-amine (abbreviated as PCBASF) and , 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)benzene Luvazolyl biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl) )-9-phenylcarbazole (abbreviation: CzTP), 3,3'-bis(9-phenyl-9 Compounds having a carbazole skeleton, such as H-carbazole (abbreviated as PCCP), and 4, 4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation) :DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluorine [Len-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4- [4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibene Compounds containing a thiophene skeleton, such as zothiophene (abbreviation: DBTFLP-IV), and 4 ,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl) furans such as phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II) Examples include compounds having a skeleton. Among those mentioned above, compounds having an aromatic amine skeleton and Compounds with a carbazole skeleton are reliable and have high hole transport properties. This is preferable because it also contributes to reducing dynamic voltage.

[0072] Examples of materials with electron transport properties include bis(10-hydroxybenzo[h]quino (Linato) Beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-quinolinola (4-phenylphenolate)aluminum(III) (abbreviation: BAlq), bis(8 -Quinolinolato) Zinc(II) (abbreviation: Znq), Bis[2-(2-benzoxazolyl) )phenolate]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl] Metal complexes such as phenolate]zinc(II) (abbreviation: ZnBTZ) and 2-(4-biphenolate) Niryl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated) Name: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butyl) Phenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(pt [ert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviation) :OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl )phenyl]-9H-carbazole (abbreviation: CO11), 2,2',2''-(1,3, 5-Benzenetriyl)tris(1-phenyl-1H-benzoimidazole) (abbreviation: T PBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1 Polyazole skeletons such as H-benzoimidazole (abbreviation: mDBTBIm-II) heterocyclic compounds such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[ f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothi Offen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)bife [Nyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 4, 6-Bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mP) nP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviated) Heterocyclic compounds having a diazine skeleton, such as (name: 4,6mDBTP2Pm-II), and 3, 5-Bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DC) zPPy), 1,3,5-tri[3-(3-pyridyl)-phenyl]benzene (abbreviation: T Examples include heterocyclic compounds having a pyridine skeleton, such as mPyPB. Among those mentioned above, Heterocyclic compounds with a diazine skeleton or a pyridine skeleton are highly reliable. It is good and preferable. In particular, heterocyclic compounds having a diazine (pyrimidine or pyrazine) skeleton. It has high electron transport properties and also contributes to reducing the drive voltage.

[0073] Furthermore, the host material may be a mixture of multiple substances, and the mixed host material When used, a mixture of electron-transporting material and hole-transporting material is used. Preferably, by mixing an electron-transporting material with a hole-transporting material. Furthermore, the transport properties of the light-emitting layer 113 can be easily adjusted, and the recombination region can be easily controlled. This is possible. The ratio of the content of hole-transporting material to electron-transporting material is the ratio of hole-transporting material content. The ratio of electron-transporting material to electron-transporting material should be 1:9 to 9:1.

[0074] Furthermore, these mixed materials may form excited complexes. These excited complexes are luminescent materials. It forms an excited complex that emits light that overlaps with the wavelength of the lowest energy absorption band. By selecting the right combination, energy transfer becomes smoother, and luminescence is obtained more efficiently. This is preferable because it allows for a reduction in the driving voltage.

[0075] The electron transport layer 114 is a layer containing a substance that has electron transport properties. In terms of quality, the materials listed above are those with electron transport properties that can be used in the host material. It is possible to use things.

[0076] Between the electron transport layer 114 and the cathode 102, lithium fluoride is used as part of the cathode 102. Alkaline compounds such as LiF, cesium fluoride (CsF), and calcium fluoride (CaF2) Metals, alkaline earth metals, or compounds thereof may be provided. Materials with electron transport properties. A layer made of alkali metals or alkaline earth metals or compounds thereof is contained within it. Alternatively, an electride may be used. For example, calcium Examples include materials obtained by adding a high concentration of electrons to a mixed oxide of aluminum.

[0077] Here, we will describe an example of a particularly preferred structure in a light-emitting element according to one aspect of the present invention.

[0078] In one embodiment of the present invention, the light-emitting element contains a host material comprising a condensed aromatic ring skeleton of 3 to 6 rings. It is preferable that the substance is such that it contains three to six condensed aromatic ring skeletons. For example, CzPA, 7-[4-(10-phenyl-9-antryl)phenyl]-7H- Dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 9-phenyl-3-[4 -(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCz) PA), 4-[3-(9,10-diphenyl-2-anthryl)phenyl]dibenzofuran n (abbreviation: 2mDBFPPA-II), t-BuDNA, 9-(2-naphthyl)-10- Anthracene such as [4-(1-naphthyl)phenyl]anthracene (abbreviation: BH-1) Substances with a rib skeleton, 5,12-diphenyltetracene (abbreviation: DPT), rubrene, 2,8-di-tert-butyl-5,11-bis(4-tert-butylphenyl)-6 Substances having a tetracene skeleton, such as 12-diphenyltetracene (abbreviation: TBRb) or, 1,3,5-tri(1-pyrenyl)benzene (abbreviation: TPB3), 9,9-bis[4 -(1-pyrenyl)phenyl]-9H-fluorene (abbreviation: BPPF), 2,7-bis( 1-pyrenyl)-spiro-9,9'-bifluorene (abbreviation: Spyro-pye) and other substances having a pyrene skeleton, and 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP) and other substances having a perylene skeleton, and substances having a fluoranthene skeleton , substances having a dibenzochrysene skeleton, and the like. Among these, as described above, anthra cene skeleton-containing substances are particularly preferable.

[0079] In this case, in the light-emitting element according to one embodiment of the present invention, the electron transport layer 114 is a first electron transport layer 114 -1 and a second electron transport layer 114-2, and preferably has a two-layer structure. Further, the first electro The materials constituting the child transport layer 114-1 and the second electron transport layer 114-2 are each different heteroaroma It is preferably a material containing a ring skeleton. As described above, the first electron transport layer 114-1 and By making the heteroaromatic ring skeletons of the materials used for the second electron transport layer 114-2 different from each other, the LUMO level of the material constituting the first electron transport layer 114-1 is adjusted to be lower than that of the host material and the second electro it can be constructed at a position lower (deeper) than the LUMO level of the material constituting the child transport layer 114-2 this becomes possible.

[0080] Note that the heteroaroma constituting the first electron transport layer 114-1 and the second electron transport layer 114-2 the substance having a cyclic skeleton is preferably a substance having a 6-membered nitrogen-containing heteroaromatic ring skeleton able. A substance having a 6-membered nitrogen-containing heteroaromatic ring skeleton has a 5-membered nitrogen-containing heterocyclic skeleton (pyrro le, indole, carbazole, imidazole, benzimidazole, triazole, benzotriazole, etc.), it has higher reliability as an electron acceptor than substances having the above, so reliability A light-emitting element with good properties can be obtained. Furthermore, it has a 6-membered nitrogen-containing heteroaromatic ring skeleton. Substances tend to have deeper LUMO levels than substances with a five-membered nitrogen-containing heterocyclic skeleton. Therefore, it is particularly suitable as a material for constituting the first electron transport layer 114-1.

[0081] Therefore, the material having a heteroaromatic ring skeleton that constitutes the first electron transport layer 114-1 is It is preferable that it contains a lyazine skeleton or a diazine skeleton (especially a pyrazine skeleton or pyrimidine skeleton). Among these, substances containing a condensed heteroaromatic ring skeleton are preferred. A preferred example of a substance containing a condensed heteroaromatic ring skeleton is the highly reliable benzoquinazoline. Examples include substances containing a skeleton or a dibenzoquinoxaline skeleton, particularly the dibenzoquinoxaline skeleton. This is preferable because it tends to deepen the LUMO level. One embodiment of the present invention having such a configuration. The light-emitting element is designed to have a long lifespan and exhibit minimal brightness degradation due to the accumulation of operating time. It is possible.

[0082] The material having a hetero-aromatic ring skeleton that constitutes the second electron transport layer 114-2 is in contact with the cathode. Considering the combination, substances having a pyridine skeleton or a bipyridine skeleton are preferred. Also, the first The electron transport layer 114-1 is composed of a material having a heteroaromatic ring skeleton, such as a triazine skeleton or dia If it contains a din skeleton (especially a pyrazine skeleton or pyrimidine skeleton), then a pyridine skeleton or bipyrimidine skeleton may be present. Because the din skeleton has a higher LUMO level than the triazine and diazine skeletons, This combination is preferable. Even if the pyridine skeleton or bipyridine skeleton forms a condensed ring, For example, it may form a phenanthroline skeleton.

[0083] The complex aromatic ring bones constituting the first electron transport layer 114-1 and the second electron transport layer 114-2 Substances that have a grade include 2mDBTPDBq-II, 2mDBTBPDBq-II, 2 -{3-[3-(2,8-diphenyldibenzothiophen-4-yl)phenyl]pheni Ludibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-III), 2-{ 3-[3-(6-phenyldibenzothiophen-4-yl)phenyl]phenyl}diben Zo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-IV), 2-[4-(9-f Phenyl-9H-carbazole-3-yl)phenyl]dibenzo[f,h]quinoxaline ( Abbreviation: PCPDBq), 2-[3-(3,6-diphenyl-9H-carbazole-9-i Phenyl dibenzo[f,h]quinoxaline (abbreviation: 2mCzPDBq-III), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f, [h]Quinoxaline (abbreviation: 2mCzBPDBq), 7-[3-(dibenzothiophene-4 -yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II) ), 7-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[ Dibenzoquinoxa A substance having a phosphorus skeleton, 2,2'-(pyridine-2,6-diyl)bis(4-phenylbe Benzoquinazolin (abbreviation: 2,6(P-Bqn)2Py) A substance having a skeleton, 4,6mDBTP2Pm-II, 4,6-bis[3-(9H-cal [Bazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 4-[3 '-(dibenzothiophen-4-yl)biphenyl-3-yl]benzoflo[3,2-d pyrimidine (abbreviation: 4mDBTBPBfpm-II), 4-{3-[3'-(9H-ca rbazol-9-yl)]biphenyl-3-yl}benzofuro[3,2-d]pyrimidine (abbreviation: 4mCzBPBfPm), 4,6-bis(3,5-di(pyridin-3-yl)ph enyl)-2-methylpyrimidine (abbreviation: B3PYMPM), 2,2'-(pyridine-2 ,6-diyl)bis(4,6-diphenylpyrimidine) (abbreviation: 2,6(P2Pm)2P y) substances having a pyrimidine skeleton, pyrazino[2,3-f][1,10]phena nthroline-2,3-dicarbonitrile (abbreviation: PPDN), 2,3-diphenylpyrido [2,3-b]pyrazine (abbreviation: 2PYPR), 2,3-diphenylpyrido[3,4-b pyrazine (abbreviation: 3PYPR) substances having a pyrazine skeleton, 2,4,6-tri s(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3Tzn), 2,4,6- tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazi ne (abbreviation: TmPPPyTz), 3-(4-(9H-carbazol-9-yl)phenyl )-9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9H-carbazo le (abbreviation: CPCBPTz) substances having a triazine skeleton, bathocuproine (abbreviation: BCP), bathophenanthroline (abbreviation: BPhen), 2,9-bis(naphtha len-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPh en), 4,4'-di(1,10-phenanthrolin-2-yl)biphenyl (abbreviation: P hen2BP) substances having a phenanthroline skeleton, 4,4'-bis[3-(9 H-carbazole-9-yl)phenyl]-2,2'-bipyridine (abbreviation: 4,4'mC) zP2BPy), 4,4'-bis[3-(dibenzothiophen-4-yl)phenyl]- 2,2'-bipyridine (abbreviation: 4,4'mDBTP2BPy-II), 4,4'-bis[ 3-(dibenzofuran-4-yl)phenyl]-2,2'-bipyridine (abbreviation: 4,4' Substances having a bipyridine skeleton such as DBfP2BPy-II, Tris[2,4,6- Trimethyl-3-(3-pyridyl)phenyl]borane (abbreviation: 3TPYMB), 1,3, 5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), 3,3' ,5,5'-tetra[(m-pyridyl)-phen-3-yl]biphenyl (abbreviation: BP4) mPy), 1,3-bis[3,5-di(pyridine-3-yl)phenyl]benzene (abbreviation) Examples include substances having a pyridine skeleton such as :BmPyPhB. A condensed aromatic ring skeleton with 3 to 6 rings that can be used as the host material in the middle and above. From among the substances listed as containing the host material, the LUMO level of the material constituting the host material and The LUMO level of the material constituting electron transport layer 2 114-2 is the same as that of electron transport layer 114-1 If you select materials so that they are located at a higher (shallower) energy level than the LUMO level of the materials that make up the system Yes.

[0084] Furthermore, in a light-emitting element having the above preferred configuration, the hole injection layer 111 is a metal acid A light-emitting device using a composite material consisting of a ion and a hole-transporting material has particularly high luminescence efficiency (external quantum effect). A light-emitting element with good efficiency (e.g., current efficiency) can be made. In this device, an organic acceptor, particularly HAT-CN, is used as the hole injection layer in a light-emitting element. Therefore, by using the present invention's configuration, the roll-off of efficiency in the high-brightness region is reduced, and high brightness This makes it possible to realize light-emitting elements that are both high-speed and highly efficient.

[0085] Alternatively, a charge generation layer 116 may be provided instead of the electron injection layer 115 (Figure 1(B)). The charge generating layer 116 generates holes in the layer adjacent to the cathode side of the layer when an electric potential is applied. This refers to a layer that can inject electrons into the layer in contact with the pole. The charge generation layer 116 is, It includes at least a P-type layer 117. The P-type layer 117 constitutes the hole injection layer 111 described above. It is preferable to form it using the composite materials listed as materials that can be used. Also, the P-type layer 117 is a composite material comprising a film containing the above-mentioned acceptor material and a hole transport material. It may also be constructed by laminating a film containing a material. By applying a potential to the P-type layer 117, Electrons are injected into the electron transport layer 114 and holes into the cathode 102, causing the light-emitting element to operate.

[0086] In addition to the P-type layer 117, the charge generation layer 116 also includes an electron relay layer 118 and an electron injection buff. It is preferable that one or both of the layers 119 are provided.

[0087] The electron relay layer 118 contains at least an electron-transporting material, and the electron injection buffer layer 1 It has the function of preventing interaction between 19 and the P-type layer 117, thereby enabling smooth electron transfer. The LUMO level of the electron-transporting material contained in the relay layer 118 is in the P-type layer 117. The LUMO level of the acceptor material and the charge generation layer 116 in the electron transport layer 114 It is preferable that the LUMO level is between the LUMO level of the material contained in the contacting layer. Electron relay layer 11 Specific energy levels of the LUMO level in electron-transporting materials used in 8 The voltage should be -5.0 eV or higher, preferably -5.0 eV to -3.0 eV. As for electron-transporting materials used in the electron relay layer 118, phthalocyanine-based materials are used. It is preferable to use a material or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0088] The electron injection buffer layer 119 contains alkali metals, alkaline earth metals, rare earth metals, and These compounds (alkali metal compounds (oxides such as lithium oxide, halides, carbon dioxide)) (including carbonates such as lithium and cesium carbonate), alkaline earth metal compounds (oxides, halogens) Compounds of rare earth metals (including oxides, halides, and carbonates) or rare earth metal compounds (oxides, halides, and carbonates) It is possible to use materials with high electron injection capabilities, such as (including)).

[0089] Furthermore, the electron injection buffer layer 119 contains an electron transporting substance and a donor substance. If formed, alkali metals, alkaline earth metals, and rare earth metals are used as donor substances. The genus, and these compounds (alkali metal compounds (oxides such as lithium oxide, halogenated compounds) Substances, including carbonates such as lithium carbonate and cesium carbonate, alkaline earth metal compounds (oxides) (including halides and carbonates), or compounds of rare earth metals (oxides, halides, In addition to carbonates, tetrathianaphthalene (abbreviation: TTN), nickelosene, and decamene are also included. Organic compounds such as tyrnickerosene can also be used. Furthermore, substances with electron transport properties can also be used. This is formed using the same material as the electron transport layer 114 described earlier. It is possible.

[0090] The material forming cathode 102 has a small work function (specifically, 3.8 eV or less). Metals, alloys, electrically conductive compounds, and mixtures thereof can be used. Specific examples of such cathode materials include alkali gold such as lithium (Li) and cesium (Cs). The genus, and elements such as magnesium (Mg), calcium (Ca), and strontium (Sr). Elements belonging to Group 1 or Group 2 of the periodic table, and alloys containing them (MgAg, Al Rare earth metals such as Li, europium (Eu), ytterbium (Yb), and these Examples include alloys containing such materials. However, between the cathode 102 and the electron transport layer, an electron injection layer is present. By providing this, regardless of the magnitude of the work function, Al, Ag, ITO, silicon or Various conductive materials such as indium oxide-tin oxide containing silicon oxide are used as cathode 102. It can be used. These conductive materials are produced using dry methods such as vacuum deposition and sputtering, as well as inkjet methods. It is possible to deposit films using methods such as spin coating. Furthermore, wet deposition can be performed using the sol-gel method. It may be formed by a mold, or by a wet process using a paste of a metallic material.

[0091] Furthermore, various methods can be used to form the EL layer 103, regardless of whether they are dry or wet methods. This can be done using methods such as vacuum deposition, gravure printing, offset printing, and screen printing. You may use printing methods, inkjet methods, or spin coating methods.

[0092] Furthermore, each electrode or layer described above may be formed using different film deposition methods.

[0093] The configuration of the layer provided between the anode 101 and the cathode 102 is not limited to the above. However, the light-emitting region and the metal used in the electrodes and carrier injection layer are in close proximity. To suppress the resulting quenching, positive A configuration in which a light-emitting region is provided where pores and electrons recombine is preferable.

[0094] Furthermore, the hole transport layer and electron transport layer in contact with the light-emitting layer 113, and especially the regeneration in the light-emitting layer 113, The carrier transport layer near the convergence region suppresses energy transfer from excitons generated in the light-emitting layer. Therefore, the band gap is the luminescent material that makes up the luminescent layer or the luminescent material contained in the luminescent layer. It is composed of materials with a band gap larger than the band gap of the photocentral material. This is preferable.

[0095] Next, we have a light-emitting element (multilayer element, tandem element) with a configuration in which multiple light-emitting units are stacked. The embodiment of (also known as) will be explained with reference to Figure 1(C). This light-emitting element has an anode and a cathode. This is a light-emitting element having multiple light-emitting units between the pole and the element. One light-emitting unit is shown in Figure 1. It has a configuration almost identical to the EL layer 103 shown in (A). In other words, the light emission shown in Figure 1(C) The element is a light-emitting element having multiple light-emitting units, as shown in Figure 1(A) or Figure 1(B). A light-emitting element can be defined as a light-emitting element having one light-emitting unit.

[0096] In Figure 1(C), a first light-emitting element is placed between the first electrode 501 and the second electrode 502. The knit 511 and the second light-emitting unit 512 are stacked, and the first light-emitting unit 511 A charge generation layer 513 is provided between the first electrode and the second light-emitting unit 512. Electrode 501 and the second electrode 502 correspond to the anode 101 and cathode 102 in Figure 1(A), respectively. Furthermore, the same thing described in the explanation of Figure 1(A) can be applied. Also, the first Even if the light unit 511 and the second light-emitting unit 512 have the same configuration, they may have different configurations. That's good too.

[0097] When a voltage is applied to the first electrode 501 and the second electrode 502, the charge generation layer 513 generates It has the function of injecting electrons into one light-emitting unit and holes into the other light-emitting unit. That is, in Figure 1(C), the potential of the first electrode is higher than the potential of the second electrode. When a voltage is applied in such a manner, the charge generation layer 513 generates electrons in the first light-emitting unit 511. Any method that injects a substance and injects holes into the second light-emitting unit 512 is acceptable.

[0098] The charge generation layer 513 is formed with the same configuration as the charge generation layer 116 described in Figure 1(B). It is preferable that the composite material of organic compounds and metal oxides has good carrier implantation and carrier transport properties. Due to its excellent transmission properties, it can achieve low-voltage and low-current operation. When the anode side of the knit is in contact with the charge generation layer 513, the charge generation layer 513 emits light. Since it can also serve as the hole injection layer in the knit, the light-emitting unit does not have a hole transport layer. It's fine.

[0099] Furthermore, if an electron injection buffer layer 119 is provided, the electron injection buffer layer 119 is the anode. In order to play the role of an electron injection layer in the light-emitting unit on the anode side, the light-emitting unit on the anode side must Furthermore, there is no need to form an electron injection layer.

[0100] Figure 1(C) illustrates a light-emitting element with two light-emitting units, but what if there are three or more? The same principle can be applied to light-emitting devices formed by stacking multiple light-emitting units. As in the form of a light-emitting element, multiple light-emitting units are placed between a pair of electrodes in a charge generation layer 51 By dividing and arranging the elements in a 3-part system, high-brightness illumination is possible while maintaining a low current density, and furthermore... This enables the creation of long-life elements. Furthermore, it allows for low-voltage operation and enables the creation of light-emitting devices with low power consumption. It is possible.

[0101] Furthermore, by making the light-emitting color of each light-emitting unit different, the entire light-emitting element... This allows you to obtain light emission of the desired color. For example, a light-emitting element having two light-emitting units. In this configuration, the first light-emitting unit produces red and green light, and the second light-emitting unit produces blue light. By doing so, it is also possible to obtain a light-emitting element that emits white light as a whole.

[0102] The above configuration may be appropriately combined with other embodiments or other configurations within this embodiment. This is possible.

[0103] (Embodiment 2) In this embodiment, a light-emitting device using a light-emitting element containing the organic compound described in Embodiment 1 is provided. I will explain this.

[0104] In this embodiment, a light-emitting element containing the organic compound described in Embodiment 1 is used to create the light-emitting element. The light-emitting device will be explained using Figure 2. Figure 2(A) is a top view showing the light-emitting device. Figure 2(B) is a cross-sectional view of Figure 2(A) cut along lines AB and CD. This light-emitting device The drive circuit section (source line drive circuit), shown by the dotted line, controls the emission of light from the light-emitting element. It includes a path (601), a pixel section (602), and a drive circuit section (gate line drive circuit) (603). 604 is the sealing substrate, 605 is the sealing material, and the area inside the sealing material 605 is a space. It's set to 607.

[0105] The routing wiring 608 is connected to the source line drive circuit 601 and the gate line drive circuit 603. FPC (Flexible Printed Circuit) is a wiring used to transmit signals and serves as an external input terminal. (Lindt Circuit) Video signal, clock signal, start signal, reset signal from 609 Receives, etc. Note that only FPC is shown in the diagram here, but this FPC has print A circuit board (PWB) may be attached. The light-emitting device in this specification includes light-emitting This includes not only the device itself, but also the state in which the FPC or PWB is attached to it. do.

[0106] Next, the cross-sectional structure will be explained using Figure 2(B). The drive circuit is located on the element substrate 610. A section and a pixel section are formed, but here, the source line drive circuit 601 is the drive circuit section. This shows one of the pixels in the pixel section 602.

[0107] The element substrate 610 is a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, etc. FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fiber) Fabricated using a plastic substrate made of polyester or acrylic (e.g., fluoride). That's all you need to do.

[0108] The structure of the transistors used in pixels and driving circuits is not particularly limited. For example, reverse st It can be a staggered transistor or a galvanized transistor. Either a bottom-gate transistor or a bottom-gate transistor is acceptable. The semiconductor materials used are not particularly limited; for example, silicon, germanium, silicon carbide, and nitrogen. Gallium oxide can be used, or In-Ga-Zn metal oxides, etc. An oxide semiconductor containing at least one of gallium, gallium, or zinc may also be used.

[0109] The crystallinity of semiconductor materials used in transistors is not particularly limited; amorphous semiconductors are also available. Crystalline semiconductors (microcrystalline semiconductors, polycrystalline semiconductors, single-crystal semiconductors, or semiconductors with a crystalline region in part) Any semiconductor (having a region) may be used. If a semiconductor with crystalline properties is used, This is preferable because it suppresses the degradation of the DISTA characteristics.

[0110] In addition to the transistors provided in the above-mentioned pixels and driving circuits, there are also touch sensors, etc., which will be described later. For semiconductor devices such as transistors used in this application, oxide semiconductors are preferred. In particular, it is preferable to use oxide semiconductors that have a wider band gap than silicon. By using oxide semiconductors with a wider bandgap than silicon, the transistor can be turned off. The current in this state can be reduced.

[0111] The above oxide semiconductor preferably contains at least indium (In) or zinc (Zn). It seems so. Also, In-M-Zn oxides (where M is Al, Ti, Ga, Ge, Y, Zr, Sn It is an oxide semiconductor containing an oxide (such as a metal like La, Ce, or Hf). More preferable.

[0112] In particular, the semiconductor layer has multiple crystalline portions, and the c-axis of the crystalline portion is the surface on which the semiconductor layer is formed. , or oriented perpendicular to the upper surface of the semiconductor layer, and without grain boundaries between adjacent crystal portions. It is preferable to use an oxide semiconductor film.

[0113] By using such materials as semiconductor layers, fluctuations in electrical properties are suppressed, and reliability is improved. High-quality transistors can be achieved.

[0114] Furthermore, due to its low off-current, the transistor having the aforementioned semiconductor layer is a transistor It is possible to retain the charge stored in the capacity over a long period of time through such a mechanism. By applying a transistor to each pixel, the gradation of the image displayed in each display area is maintained while driving It also becomes possible to stop the operating circuit. As a result, electronic devices with extremely reduced power consumption can be produced. It can be achieved.

[0115] It is preferable to provide an undercoat to stabilize the characteristics of the transistor. Silicon oxide film, silicon nitride film, silicon oxide nitride film, silicon nitride oxide film, etc. It can be fabricated using an insulating film, either as a single layer or in a multilayer configuration. The undercoat is fabricated by sputtering. CVD (Chemical Vapor Deposition) method (Plasma CVD) Methods such as thermal CVD, MOCVD (Metal Organic CVD), and ALD Using methods such as (Atomic Layer Deposition), coating, and printing, the shape can be formed. It is possible. Furthermore, a base coat does not need to be applied unless necessary.

[0116] Note that FET623 is one of the transistors formed in the drive circuit section 601. Yes, it exists. Furthermore, the drive circuit can be formed using various CMOS, PMOS, or NMOS circuits. It is fine to do so. Also, in this embodiment, a driver-integrated type in which the drive circuit is formed on the substrate is However, this is not always necessary, and the drive circuit can be formed externally rather than on the circuit board. ru.

[0117] Furthermore, the pixel section 602 includes a switching FET 611 and a current control FET 612 and It is formed by a plurality of pixels, including a first electrode 613 electrically connected to the drain. However, it is not limited to this, and the pixel section may be a combination of three or more FETs and a capacitive element. That's good too.

[0118] Furthermore, an insulator 614 is formed covering the end of the first electrode 613. Here, It can be formed by using a photosensitive acrylic resin film of type D.

[0119] Furthermore, in order to ensure good coverage of the EL layer and the like that will be formed later, the upper end of the insulator 614 Alternatively, a curved surface with curvature is formed at the lower end. For example, the material of the insulator 614. When a positive-type photosensitive acrylic is used, the radius of curvature (0) is only at the upper end of the insulator 614. It is preferable to have a curved surface having a thickness of 0.2 μm to 3 μm. Also, as the insulator 614 Either a negative-type or positive-type photosensitive resin can be used.

[0120] An EL layer 616 and a second electrode 617 are formed on the first electrode 613, respectively. Here, the material used for the first electrode 613 which functions as an anode is, work function It is desirable to use a material with a large ion content. For example, ITO film or silicon-containing ink Dium-tin oxide film, indium oxide film containing 2-20 wt% zinc oxide, titanium nitride film, In addition to single-layer films such as chromium films, tungsten films, Zn films, and Pt films, titanium nitride films and aluminum films are also available. Lamination with a film mainly composed of aluminum, titanium nitride film and aluminum-based film and titanium nitride film A three-layer structure with a tan film can be used. Furthermore, a laminated structure can improve the resistance of the wiring. It has low resistance, provides good ohmic contact, and can also function as an anode. ru.

[0121] Furthermore, the EL layer 616 can be coated using a deposition method with a deposition mask, an inkjet method, or a spin coat. It is formed by various methods such as the law. The EL layer 616 is as described in Embodiment 1. It includes the composition. In addition, other materials that make up the EL layer 616 include low molecular weight compounds, Alternatively, it may be a polymer compound (including oligomers and dendrimers).

[0122] Furthermore, the material used for the second electrode 617, which is formed on the EL layer 616 and functions as a cathode As for materials, materials with a low work function (Al, Mg, Li, Ca, or alloys of these) It is preferable to use a compound (MgAg, MgIn, AlLi, etc.). Note that the EL layer 6 If the light generated in 16 passes through the second electrode 617, then the second electrode 617 is a film. A thin metal film with reduced thickness and a transparent conductive film (ITO, containing 2-20 wt% zinc oxide). Lamination with indium tin oxide containing indium and silicon, zinc oxide (ZnO), etc. is used. It's good to have them.

[0123] The first electrode 613, the EL layer 616, and the second electrode 617 form a light-emitting element. The light-emitting element is the light-emitting element described in Embodiment 1. Note that there are multiple pixel units. Although a light-emitting element is formed, in the light-emitting device of this embodiment, The light-emitting element described in 1 may include both the light-emitting element described in 1 and light-emitting elements having other configurations.

[0124] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, A light-emitting element is placed in the space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. The structure is equipped with child 618. Furthermore, the space 607 is filled with a filler material. In addition to cases where an inert gas (such as nitrogen or argon) is used for filling, this also applies when a sealing material is used for filling. In addition, a recess is formed in the encapsulating substrate, and a desiccant is placed there to prevent deterioration due to moisture. This configuration is preferable because it can suppress [the problem].

[0125] Furthermore, it is preferable to use epoxy resin or glass frit for the sealant 605. Furthermore, it is desirable that these materials be as impermeable to moisture and oxygen as possible. In addition to glass substrates and quartz substrates, FRP (Fiber Reinforced Plastic) is also used as a material for the sealing substrate 604. Reinforced Plastics, PVF (polyvinyl fluoride), polyethylene A plastic substrate made of sterling silver or acrylic can be used.

[0126] Although not shown in Figure 2, a protective film may be provided on the second electrode. The protective film is made of organic resin. It can be formed with a film or an inorganic insulating film. Also, so as to cover the exposed portion of the sealing material 605, A protective film may be formed. Furthermore, the protective film may be on the surface and sides of the pair of substrates, and as a sealing layer. It can be installed to cover exposed sides of insulating layers, etc.

[0127] The protective film can be made of a material that is impermeable to impurities such as water. Therefore, This effectively suppresses the diffusion of impurities such as water from the outside into the interior.

[0128] Materials that make up the protective film include oxides, nitrides, fluorides, sulfides, ternary compounds, and gold. A compound or polymer can be used, for example, aluminum oxide, hafnium oxide, Hafnium silicate, lanthanum oxide, silicon dioxide, strontium titanate, tantalum oxide Titanium dioxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide Calcium oxide, cerium oxide, scandium oxide, erbium oxide, vanadium oxide, or indigo oxide Materials containing zinc, etc., as well as aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, Contains titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, or gallium nitride, etc. Materials, nitrides containing titanium and aluminum, oxides containing titanium and aluminum Substances, oxides containing aluminum and zinc, sulfides containing manganese and zinc, cerium and sulfides containing strontium, oxides containing erbium and aluminum, Materials containing oxides such as thorium and zirconium can be used.

[0129] The protective film is formed using a film deposition method that provides good step coverage. This is preferable. One such method is atomic layer deposition (ALD). There is a deposition method. Materials that can be formed using the ALD method are preserved. It is preferable to use it as a protective film. By using the ALD method, a dense film can be created that is free from cracks and pinholes. It is possible to form a protective film with reduced defects or a uniform thickness. This reduces the damage inflicted on the processed member when forming a protective film.

[0130] For example, by forming a protective film using the ALD method, surfaces with complex uneven shapes, and A uniform and low-defect protective film can be formed on the top, sides, and back surfaces of the panel. ru.

[0131] As described above, a light-emitting device fabricated using the light-emitting element described in Embodiment 1 is obtained. It is possible.

[0132] Since the light-emitting device in this embodiment uses the light-emitting element described in Embodiment 1, A light-emitting device with good characteristics can be obtained. Specifically, the light-emitting device described in Embodiment 1 Because optical elements are light-emitting elements with a long lifespan, they can be used to create highly reliable light-emitting devices. Furthermore, the light-emitting device using the light-emitting element described in Embodiment 1 has good luminous efficiency, therefore, power consumption It is possible to create a light-emitting device with low power.

[0133] Figure 3 shows a light-emitting element that emits white light, and a colored layer (color filter), etc. An example of a light-emitting device that has been made full-color by the above is shown. Figure 3(A) shows substrate 1001, underlay insulation Edge film 1002, gate insulating film 1003, gate electrodes 1006, 1007, 1008, 1 The interlayer insulating film 1020, the second interlayer insulating film 1021, the peripheral portion 1042, the pixel portion 1040, Drive circuit section 1041, first electrodes 1024W, 1024R, 1024G, 10 24B, partition wall 1025, EL layer 1028, second electrode 1029 of light-emitting element, sealing substrate 10 31. The sealing material 1032 and other components are shown in the illustration.

[0134] Furthermore, in Figure 3(A), the colored layers (red colored layer 1034R, green colored layer 1034G, blue) are shown. The colored layer 1034B is provided on the transparent substrate 1033. Also, a black matrix is ​​provided. 1035 may be further provided. A transparent substrate having a colored layer and a black matrix. 1033 is aligned and fixed to substrate 1001. Note that the colored layer and black matrix Rix 1035 is covered with an overcoat layer 1036. Also, Figure 3(A) shows odor In this case, there is an emissive layer that allows light to escape to the outside without passing through the colored layer, and a layer that allows light to escape to the outside by passing through the colored layers of each color. There is a light-emitting layer, and light that does not pass through the colored layer is white, while light that passes through the colored layer is red, green, and blue. Therefore, images can be represented using four colored pixels.

[0135] Figure 3(B) shows the colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer Example of forming layer 1034B) between the gate insulating film 1003 and the first interlayer insulating film 1020. This was shown. Thus, the colored layer is provided between the substrate 1001 and the sealing substrate 1031. That's good too.

[0136] Furthermore, in the light-emitting device described above, light is taken to the substrate 1001 side on which the FET is formed. Although the light-emitting device was designed with a bottom-emission structure, the light-emitting element was directed towards the sealing substrate 1031. It can also be used as a light-emitting device with an extraction structure (top emission type). Top emission type A cross-sectional view of the light-emitting device is shown in Figure 4. In this case, the substrate 1001 is a substrate that does not transmit light. This is possible. Until the connecting electrode that connects the FET and the anode of the light-emitting element is fabricated, the bottom It is formed in the same way as an emission-type light-emitting device. Then, the third interlayer insulating film 1037 is attached to the electrode. It is formed covering 1022. This insulating film may also play a planarizing role. Third interlayer The insulating film 1037 is formed using the same material as the second interlayer insulating film, as well as other known materials. It is possible.

[0137] The first electrodes 1024W, 1024R, 1024G, and 1024B of the light-emitting element are positive here. This is referred to as the electrode, but it can also be the cathode. Furthermore, top-emission type light emission as shown in Figure 4 is also possible. In the case of a device, it is preferable that the first electrode be a reflective electrode. The configuration of the EL layer 1028 is The configuration is as described in Embodiment 1 as the EL layer 103, and the light emission is white. The device structure should be such that the desired result can be obtained.

[0138] In the top emission structure shown in Figure 4, the colored layer (red colored layer 1034R, green colored layer) The sealing is performed using a sealing substrate 1031 having a colored layer 1034G and a blue colored layer 1034B. This is possible. The encapsulating substrate 1031 has a black matrix positioned between the pixels. A colored layer (red colored layer 1034R, green colored layer 1034G) may be provided. The blue colored layer (1034B) and the black matrix are covered by an overcoat layer. It is acceptable to leave it as is. Furthermore, the sealing substrate 1031 shall be a light-transmitting substrate. Also, Here, we have shown an example of full-color display using four colors: red, green, blue, and white, but it is not limited to red. Alternatively, full-color display may be performed using four colors: yellow, green, and blue, or three colors: red, green, and blue.

[0139] In top-emission type light-emitting devices, the application of a microcavity structure is preferable. The light-emitting element having a microcavity structure has a first electrode as a reflective electrode and a second electrode as a semi-reflective electrode. This is obtained by using a transmissive / semi-reflective electrode. Between the reflective electrode and the semi-transmissive / semi-reflective electrode It has at least an EL layer and at least an emissive layer that forms an emissive region.

[0140] The reflective electrode has a visible light reflectance of 40% to 100%, preferably 70% to 10%. It is 0%, and its resistivity is 1 × 10⁻⁶ -2 Assume the membrane is less than Ωcm thick. The semi-reflective electrode has a visible light reflectance of 20% to 80%, preferably 40% to 70%. Furthermore, its resistivity is 1 × 10⁻⁶ -2 Assume the membrane is less than Ωcm in diameter.

[0141] The light emitted from the light-emitting layer contained in the EL layer is due to the reflective electrode and the semi-transmitting / semi-reflective electrode. It is reflected and resonates.

[0142] The light-emitting element changes the thickness of the transparent conductive film, the aforementioned composite material, the carrier transport material, etc. This allows us to change the optical distance between the reflective electrode and the semitransmissive / semi-reflective electrode. Therefore, between the reflective electrode and the semitransmissive / semi-reflective electrode, the light of the resonant wavelength is amplified, and the resonant It can attenuate light of certain wavelengths.

[0143] Furthermore, the light reflected back by the reflective electrode (the first reflected light) is semitransparent from the light-emitting layer. Because it causes significant interference with the light (first incident light) that directly incident on the hyper- or semi-reflective electrode, the reflective electrode The optical distance between the light-emitting layer and the luminescent layer is (2n-1)λ / 4 (where n is a natural number greater than or equal to 1, and λ is amplified). It is preferable to adjust the wavelength of the emission. By adjusting the optical distance, the By aligning the phase of the reflected light from 1 and the first incident light, the light emitted from the light-emitting layer can be further amplified. Cut.

[0144] Furthermore, in the above configuration, even if the EL layer has a structure with multiple light-emitting layers, a single light The structure may also have an optical layer, for example, in combination with the tandem light-emitting element configuration described above. Furthermore, multiple EL layers are provided on a single light-emitting element, with a charge generation layer in between, and each EL layer has a single This may also be applied to configurations that form several or more light-emitting layers.

[0145] By having a microcavity structure, the emission intensity in the front direction at a specific wavelength is enhanced. This makes it possible to reduce power consumption. Furthermore, the four sub-colors red, yellow, green, and blue... In the case of a light-emitting device that displays images using pixels, in addition to the brightness-enhancing effect of yellow light emission, all pixels By applying microcavity structures tailored to the wavelength of each color, excellent emission characteristics can be achieved. It can be used as a device.

[0146] Since the light-emitting device in this embodiment uses the light-emitting element described in Embodiment 1, A light-emitting device with good characteristics can be obtained. Specifically, the light-emitting device described in Embodiment 1 Because optical elements are light-emitting elements with a long lifespan, they can be used to create highly reliable light-emitting devices. Furthermore, the light-emitting device using the light-emitting element described in Embodiment 1 has good luminous efficiency, therefore, power consumption It is possible to create a light-emitting device with low power.

[0147] Up to this point, we have explained active matrix type light-emitting devices, but from here on we will discuss... This section describes a sib matrix type light-emitting device. Figure 5 shows a pack fabricated by applying the present invention. This shows a sib matrix type light-emitting device. Note that Figure 5(A) is a perspective view showing the light-emitting device, Figure 5 (B) is a cross-sectional view of Figure 5(A) taken along the XY line. In Figure 5, on the substrate 951 An EL layer 955 is provided between electrode 952 and electrode 956. The end of electrode 952 It is covered with an insulating layer 953. And a partition layer 954 is provided on top of the insulating layer 953. The side walls of the partition layer 954, as they approach the substrate surface, have a certain degree of separation between one side wall and the other side wall. It has a slope that narrows as the spacing decreases. In other words, the cross-section of the partition layer 954 in the short-side direction is It is trapezoidal in shape, with the base (facing the same direction as the surface direction of the insulating layer 953 and in contact with the insulating layer 953) The upper edge (the side that faces the same direction as the plane direction of the insulating layer 953 and does not come into contact with the insulating layer 953) It is shorter than ). In this way, by providing the partition layer 954, light-emitting elements caused by static electricity, etc. This can prevent defects. Also, in passive matrix type light-emitting devices, the implementation is The light-emitting element described in Embodiment 1 is used, and the light-emitting device is highly reliable or has low power consumption. It can be used as a light-emitting device.

[0148] The light-emitting device described above uses a number of tiny light-emitting elements arranged in a matrix. Because it can be controlled, it can be suitably used as a display device for representing images. It is a light device.

[0149] Furthermore, this embodiment can be freely combined with other embodiments.

[0150] (Embodiment 3) In this embodiment, Figure 6 shows an example in which the light-emitting element described in Embodiment 1 is used as an illumination device. I will explain while referring to the following. Figure 6(B) is a top view of the lighting device, and Figure 6(A) is shown in Figure 6(B). This is a cross-sectional view.

[0151] The lighting device in this embodiment has a light-transmitting substrate 400 which is a support, and a first An electrode 401 is formed. The first electrode 401 is on the anode 101 in Embodiment 1. Corresponds to the first electrode 401. When light is extracted from the first electrode 401 side, the first electrode 401 has light-transmitting properties. It is formed using the following materials.

[0152] A pad 412 for supplying voltage to the second electrode 404 is formed on the substrate 400.

[0153] An EL layer 403 is formed on the first electrode 401. The EL layer 403 is in Embodiment 1 The configuration of the EL layer 103, or the light-emitting units 511, 512 and the charge generation layer 513 This corresponds to a combined configuration, etc. Please refer to the relevant description for details on these configurations.

[0154] The EL layer 403 is covered to form the second electrode 404. The second electrode 404 is in Embodiment 1 This corresponds to cathode 102 in the diagram. When light emission is taken from the first electrode 401 side, the second electrode The electrode 404 is formed from a highly reflective material. The second electrode 404 is in contact with the pad 412. By continuing, voltage is supplied.

[0155] The above describes a light-emitting element having a first electrode 401, an EL layer 403, and a second electrode 404. The lighting device shown in the embodiment has a light-emitting element with high luminous efficiency. Therefore, the lighting device in this embodiment can be a lighting device with low power consumption.

[0156] A substrate 400 on which a light-emitting element having the above configuration is formed, and a sealing substrate 407 are sealed together. The lighting device is completed by fixing and sealing it using 405 and 406. Sealing material 4 Either 05 or 406 is acceptable. Also, the inner sealant 406 (Figure 6(B)) A desiccant can also be mixed in (not shown), which allows it to absorb moisture. This leads to improved reliability.

[0157] Furthermore, the pad 412 and a portion of the first electrode 401 are extended outside the sealing materials 405 and 406. By providing it, it can be used as an external input terminal. Also, a converter can be placed on top of it. An IC chip 420 or similar, which incorporates such features, may also be provided.

[0158] As described above, the lighting device described in this embodiment has an EL element that is the light-emitting element described in Embodiment 1. This allows for a highly reliable light-emitting device. Furthermore, it provides a light-emitting device with good heat resistance. It can be placed there.

[0159] (Embodiment 4) In this embodiment, an example of an electronic device that includes the light-emitting element described in Embodiment 1 as a part thereof... Let me explain. The light-emitting element described in Embodiment 1 has a good lifespan and reliable light emission. It is an element. As a result, the electronic device described in this embodiment has a reliable light-emitting part. It can be used as an electronic device.

[0160] Examples of electronic devices to which the above light-emitting element is applied include television equipment (television, or television). (also called a revision receiver), monitors for computers, digital cameras, digital Video cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices) ), portable game consoles, personal digital assistants, audio playback devices, large game machines such as pachinko machines, etc. These include [examples of electronic devices]. Specific examples of these electronic devices are shown below.

[0161] Figure 7(A) shows an example of a television system. The television system is housed in a 710 enclosure. The display unit 7103 is incorporated into part 1. Also, the housing is connected by the stand 7105. This shows the configuration supporting 7101. The display unit 7103 can display video. The display unit 7103 is capable of arranging the light-emitting elements described in Embodiment 1 in a matrix. It is composed of.

[0162] The television equipment can be operated using the control switches on the housing 7101 or a separate remote control. This can be done using the device 7110. The remote control device 7110 has an operation key 7109. This allows you to control the channel and volume, and the video displayed on the display unit 7103 It can be operated. Also, the remote control unit 7110 A display unit 7107 that displays the information output from the unit may also be provided.

[0163] The television system shall consist of a receiver, modem, etc. It can receive television broadcasts, and also communicate via wired or wireless connection through a modem. By connecting to a network, one-way (sender to receiver) or two-way (sender to receiver) communication is possible. It is also possible to communicate information between recipients, or between recipients themselves.

[0164] Figure 7(B1) is a computer, consisting of the main unit 7201, the casing 7202, the display unit 7203, and a key - Includes board 7204, external connection port 7205, pointing device 7206, etc. Furthermore, this computer arranges the light-emitting elements described in Embodiment 1 in a matrix. It is manufactured by using it in the display unit 7203. The computer in Figure 7(B1) is in Figure 7( It may also be in a form like B2). The computer in Figure 7(B2) has a keyboard 720 4. A second display unit 7210 is provided instead of the pointing device 7206. The second display unit 7210 is a touch panel, and the information displayed on the second display unit 7210 is Input can be performed by operating the displayed input screen with a finger or a special pen. Furthermore, the second display unit 7210 can display not only input information but also other images. The display unit 7203 may also be a touch panel. The two screens are connected by a hinge. This prevents problems such as scratching or damaging the screen during storage or transport. This can also prevent the occurrence of negativity.

[0165] Figure 7(C) shows a portable gaming machine, which consists of two cabinets, cabinet 7301 and cabinet 7302. The housing 7301 is connected in an openable and closable manner by the connecting part 7303. A display unit 7304, which is made by arranging the light-emitting elements described in Embodiment 1 in a matrix, is incorporated. Furthermore, the display unit 7305 is incorporated into the housing 7302. Also, as shown in Figure 7(C), Other components of the gaming machine include a speaker unit 7306, a recording medium insertion unit 7307, and an LED lamp 73 08. Input means (operation key 7309, connection terminal 7310, sensor 7311 (force, displacement, position) Location, speed, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemicals, sound, time Hardness, electric field, electric current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation. It includes a function to measure (including a microphone 7312), etc. The configuration of the strip-type gaming machine is not limited to those described above, and includes at least the display unit 7304 and the display unit 7 The light-emitting elements described in Embodiment 1 are arranged in a matrix on both or one of the 305. It is sufficient to use a manufactured display unit, and the configuration may include other auxiliary equipment as appropriate. Yes, it is possible. The portable gaming machine shown in Figure 7(C) has a program or data recorded on the recording medium. It has functions to read data and display it on the display unit, and to communicate wirelessly with other portable gaming machines to exchange information. It has a sharing function. However, the functions of the portable gaming machine shown in Figure 7(C) are not limited to this. It is not limited to that and can have various functions.

[0166] Figure 7(D) shows an example of a mobile terminal. The mobile phone is incorporated into the housing 7401. In addition to the display unit 7402, there are operation buttons 7403, an external connection port 7404, and a speaker 740 5. It is equipped with a microphone 7406, etc. Note that the mobile phone 7400 is described in Embodiment 1. It has a display unit 7402 made by arranging the mounted light-emitting elements in a matrix.

[0167] The mobile terminal shown in Figure 7(D) allows users to input information by touching the display unit 7402 with their fingers or other objects. It can also be configured to allow for making phone calls or composing emails. Operations such as this can be performed by touching the display unit 7402 with a finger or the like.

[0168] The display unit 7402 has three main modes. The first is a display that primarily displays images. The first mode is display mode, the second is input mode which is mainly for inputting information such as characters. The third is display mode. This is a display + input mode, which is a combination of two modes: display mode and input mode.

[0169] For example, when making a phone call or composing an email, the display unit 7402 is used for text input. In this case, the primary text input mode should be used, and you should perform the input operation for the characters displayed on the screen. It is preferable to display a keyboard or number buttons on most of the screen of the display unit 7402. It seems so.

[0170] Furthermore, the mobile device has sensors inside that detect tilt, such as a gyroscope and an accelerometer. By installing the device, the orientation of the mobile terminal (portrait or landscape) is determined, and the screen display of the display unit 7402 is displayed accordingly. The display can be set to switch automatically.

[0171] Furthermore, screen modes can be switched by touching the display unit 7402 or by operating the housing 7401. This is done by operating button 7403. Also, the type of image displayed on display unit 7402 Therefore, it is also possible to switch between them. For example, the image signal displayed on the display unit is a video signal. Switch to display mode if it's data, or to input mode if it's text data.

[0172] Furthermore, in input mode, the signal detected by the optical sensor of the display unit 7402 is detected and displayed If there is no input via touch operation on unit 7402 for a certain period of time, the screen mode will be changed to input mode. You may also control the system to switch from that display mode to a different mode.

[0173] The display unit 7402 can also function as an image sensor. For example, the display unit 74 By touching device 02 with the palm or fingers, the user can be authenticated by capturing images of their palm print, fingerprints, etc. Furthermore, the display unit may have a backlight that emits near-infrared light or a sensing light that emits near-infrared light. Using the appropriate source, it is also possible to image finger veins, palmar veins, and other veins.

[0174] The configuration shown in this embodiment is a combination of the configurations shown in Embodiments 1 to 4 as appropriate. They can be used together.

[0175] As described above, the scope of application of the light-emitting device equipped with the light-emitting element described in Embodiment 1 is extremely broad. This light-emitting device can be applied to electronic devices in all fields. (See Embodiment 1) By using the onboard light-emitting elements, highly reliable electronic devices can be obtained.

[0176] Figure 8 shows an example of a liquid crystal display device in which the light-emitting element described in Embodiment 1 is applied as a backlight. The liquid crystal display device shown in Figure 8 consists of a housing 901, a liquid crystal layer 902, and a backlight unit. It has a to 903 and a housing 904, and the liquid crystal layer 902 is connected to the driver IC 905. Furthermore, the backlight unit 903 uses the light-emitting element described in Embodiment 1. Current is supplied via terminal 906.

[0177] By applying the light-emitting element described in Embodiment 1 to the backlight of a liquid crystal display device, A backlight with reduced power consumption can be obtained. Also, the light-emitting element described in Embodiment 1 By using this, surface-emitting lighting devices can be fabricated, and large-area applications are also possible. This allows for the creation of such devices. This allows for larger backlight areas, which in turn enables larger liquid crystal display areas. Furthermore, The light-emitting device using the light-emitting element described in Embodiment 1 can be made thinner compared to conventional devices. This also makes it possible to make display devices thinner.

[0178] Figure 9 shows an example in which the light-emitting element described in Embodiment 1 is used in a desk lamp, which is a lighting device. Yes. The desk lamp shown in Figure 9 has a housing 2001 and a light source 2002. Alternatively, the lighting device described in Embodiment 3 may be used.

[0179] Figure 10 shows a light-emitting element containing the organic compound described in Embodiment 1, installed in an indoor lighting device 300. This is an example of its use as 1. The light-emitting element containing the organic compound described in Embodiment 1 has high heat resistance. Because it is a light-emitting element, it can be used to create a lighting device with good heat resistance. Also, Embodiment 1 Since the light-emitting element containing the organic compound described can be made to cover a large area, it can be used as a large-area lighting device. It can be used in a thin form. Furthermore, the light-emitting element containing the organic compound described in Embodiment 1 is thin Therefore, it can be used as a thin lighting device.

[0180] The light-emitting element described in Embodiment 1 can also be mounted on the windshield or dashboard of an automobile. This can be done. Figure 11 shows the light-emitting element described in Embodiment 1 on the windshield of an automobile or One embodiment for use in a dashboard is shown. Display areas 5000 to 5005 are for implementation purposes. This is a display provided using the light-emitting element described in Embodiment 1.

[0181] Display area 5000 and display area 5001 are provided in an actual form on the windshield of an automobile. This is a display device equipped with the light-emitting element described in Embodiment 1. The light-emitting element described in Embodiment 1 is By fabricating electrodes 1 and 2 using translucent electrodes, the opposite side can be seen through. It can be used as a display device in a so-called see-through state. If available, it can be installed on the windshield of a car without obstructing the view. This is possible. Furthermore, if transistors or other components for driving are provided, organic semiconductor materials may be used. Organic transistors made of materials, and transistors made of oxide semiconductors, which have light-transmitting properties. Using a transistor would be a good idea.

[0182] The display area 5002 is equipped with the light-emitting element described in Embodiment 1, which is provided on the pillar portion. It is a display device. The display area 5002 displays images from an imaging device installed on the vehicle body. By doing so, the view obstructed by the pillar can be compensated for. Also, similarly, the dash The display area 5003 provided on the board section allows you to view the outside of the car, which is obstructed by the vehicle body. By displaying images from imaging devices installed on the side, blind spots are compensated for, and safety is enhanced. It is possible to project images in a way that complements the parts that are not visible, making the difference appear more natural. Safety checks can be performed without causing any disturbance.

[0183] Display areas 5004 and 5005 display navigation information, speedometer, tachometer, and mileage. It can provide various information such as departure, fuel level, gear status, and air conditioning settings. The display items and layout can be changed as needed to suit the user's preferences. Furthermore, this information can also be provided in display areas 5000 to 5003. Furthermore, display areas 5000 to 5005 can also be used as lighting devices.

[0184] Figures 12(A) and 12(B) show examples of foldable tablet devices. 2(A) is in the open state, and the tablet terminal consists of a housing 9630 and a display unit 9631a Display unit 9631b, display mode switching switch 9034, power switch 9035, It includes a power mode selector switch 9036, a fastener 9033, and an operation switch. The tablet terminal has a light-emitting device equipped with the light-emitting element described in Embodiment 1, and the display unit 96 It is manufactured by using it in either or both of the 31a and the display unit 9631b.

[0185] The display unit 9631a can be partially designated as a touch panel area 9632a, and the display will be Data can be entered by touching the operation key 9637. Note that the display unit 963 In 1a, as an example, one half of the area has a display-only function, and the other half of the area The diagram shows a configuration that includes touch panel functionality, but is not limited to this configuration. Display unit 963 The entire area of ​​1a may also be configured to have touch panel functionality. For example, the display unit 96 The entire surface of 31a is used as a touch panel with keyboard buttons, and the display unit 9631b is displayed. It can be used as a screen.

[0186] In addition, in the display unit 9631b, similar to the display unit 9631a, one of the display units 9631b The section can be designated as the touch panel area 9632b. Additionally, the touch panel keyboard... By touching the location where the display switch button 9639 is displayed with your finger or stylus, Keyboard buttons can be displayed on the display unit 9631b.

[0187] Furthermore, if you touch the touch panel area 9632a and the touch panel area 9632b simultaneously... You can also input "chi".

[0188] Additionally, the display mode switch 9034 selects the display orientation, such as portrait or landscape. You can switch between modes, such as black and white or color display. Power saving mode switching. Switch 9036 is detected by an optical sensor built into the tablet device when it is in use. The display brightness can be optimized according to the amount of light. Tablet devices use light. In addition to sensors, other detection devices such as gyroscopes, accelerometers, and other sensors that detect tilt It may be built-in.

[0189] Furthermore, Figure 12(A) shows an example where the display area of ​​display unit 9631b and display unit 9631a are the same. However, this is not particularly limited, and one size may be different from the other. The display quality may also differ. For example, one display panel can provide a higher-resolution display than the other. You can also use "ru".

[0190] Figure 12(B) shows the closed state, and in this embodiment, the tablet terminal has a casing. Body 9630, solar cell 9633, charge / discharge control circuit 9634, battery 9635, DCD An example is shown that includes a C converter 9636. Note that in Figure 12(B), the charge / discharge control circuit 963 As an example of 4, consider a configuration having a battery 9635 and a DC-DC converter 9636. It is showing.

[0191] Note that the tablet device is foldable, so when not in use, the casing 9630 is closed. This can be done. Therefore, the display units 9631a and 9631b can be protected. We can provide tablet devices that are highly durable and reliable from a long-term use perspective.

[0192] In addition, the tablet devices shown in Figures 12(A) and 12(B) are also available in various forms. Functions to display information (still images, videos, text images, etc.), calendar, date or time, etc. A function to display information on the display unit, and a touch input operation or editing of the information displayed on the display unit. It has input capabilities, and functions to control processing through various software (programs), etc. It is possible.

[0193] The touch panel is powered by a solar cell 9633 mounted on the surface of the tablet device. It can be supplied to the display unit or the video signal processing unit, etc. Note that the solar cell 9633 is If provided on one or two sides of the housing 9630, efficient charging of the battery 9635 This configuration is preferable because it allows for the following actions to be performed.

[0194] Furthermore, the configuration and operation of the charge / discharge control circuit 9634 shown in Figure 12(B) are shown in Figure 12( A block diagram is shown and explained in C). Figure 12(C) shows solar cell 9633, battery 9 635, DC-DC converter 9636, converter 9638, switch SW1 to SW3 The display unit 9631 is shown, along with the battery 9635 and the DC-DC converter 963 6. Converter 9638 and switches SW1 to SW3 control the charge and discharge as shown in Figure 12(B). This corresponds to circuit 9634.

[0195] First, let's explain an example of how the solar cell 9633 operates when generating electricity using ambient light. The electricity generated by the solar panel is converted to DC to provide the voltage needed to charge the 9635 battery. The DC converter 9636 performs either a boost or a buck. Then, the display unit 9631 operates as follows: When power charged by solar cell 9633 is used, turn on switch SW1. The converter 9638 will boost or lower the voltage to the required level for the display unit 9631. When you do not want to display anything on the display unit 9631, turn SW1 off and turn SW2 on. The configuration should be designed to charge the 9635 battery.

[0196] While the solar cell 9633 is shown as an example of a power generation method, the power generation method is not particularly limited. It is not limited to other power generation devices such as piezoelectric elements (piezoelectric elements) and thermoelectric elements (Peltier elements). The battery 9635 may be charged by some means. A contactless power transmission module that charges by sending and receiving power, or a combination of other charging methods. This configuration is also acceptable, and it does not require a means of generating electricity.

[0197] Furthermore, if the above-mentioned display unit 9631 is included, it is a tablet terminal with the shape shown in Figure 12. Not limited to this.

[0198] Figures 13(A) to (C) also show a foldable portable information terminal 9310. Figure 13 (A) shows the portable information terminal 9310 in its unfolded state. Figure 13(B) shows the unfolded state or This shows the portable information terminal 9310 in an intermediate state, transitioning from one folded state to the other. Figure 13(C) shows the folded state of the personal digital assistant 9310. Personal digital assistant 9310 It offers excellent portability when folded and a seamless, wide display area when unfolded. This provides excellent readability in the display.

[0199] The display panel 9311 is supported by three housings 9315 connected by hinges 9313. The display panel 9311 is a touch panel equipped with a touch sensor (input device). It may also be an input / output device. In addition, the display panel 9311 is connected via the hinge 9313. By bending the two housings 9315, the mobile information terminal 9310 is unfolded. It can be reversibly transformed from a folded state. A light-emitting device according to one aspect of the present invention It can be used in the display panel 9311. Display area 931 in the display panel 9311 2 is the display area located on the side of the folded portable information terminal 9310. Area 9312 contains information icons and shortcuts to frequently used apps and programs. It can display information and allow for smoother information checking and app launching. ru. [Examples]

[0200] In this embodiment, the light-emitting element 1 of one aspect of the present invention described in Embodiment 1 is described in the present invention. The results of a comparison with a comparative light-emitting element 1 having a different configuration from one embodiment of the light-emitting element are shown. Light-emitting element 1 and comparison light-emitting element 1 have a configuration that differs only in the material of the first electron transport layer. The structural formulas of the organic compounds used in the optical element 1 and the comparative light-emitting element 1 are shown below.

[0201] [ka]

[0202] (Method for fabricating light-emitting element 1) First, indium tin oxide (ITSO) containing silicon oxide is sputtered onto a glass substrate. A film was deposited using the 3D method to form the anode 101. The film thickness was 110 nm, and the electrode area was The dimensions were set to 2mm x 2mm.

[0203] Next, as a pretreatment for forming light-emitting elements on the substrate, the substrate surface is washed with water, and 200 After firing at ℃ for 1 hour, UV ozone treatment was performed for 370 seconds.

[0204] Then, 10 -4 A substrate is introduced into a vacuum deposition apparatus where the internal pressure is reduced to approximately Pa, and then vacuum deposition is performed. After vacuum firing at 170°C for 30 minutes in the heating chamber of the apparatus, the substrate is left for approximately 30 minutes. It was allowed to cool.

[0205] Next, the substrate on which the anode 101 is formed is turned so that the surface with the anode 101 is facing downwards. It is fixed to a substrate holder installed inside the air deposition apparatus, 10 -4 After reducing the pressure to approximately Pa, On electrode 101, 2, 3, 6, represented by the above structural formula (i), are deposited by a resistive heating deposition method. 7,10,11-Hexacyano-1,4,5,8,9,12-Hexazatriphenylene A hole injection layer 111 was formed by depositing (abbreviated as HAT-CN) at a 10 nm depth.

[0206] Next, on the hole injection layer 111, N-(1,1'-bipheny represented by the above structural formula (ii) is injected. Lu-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazole- 3-yl)phenyl]-9H-fluoren-2-amine (abbreviation: PCBBiF) 10n A film was deposited to a thickness of m, forming a hole transport layer 112.

[0207] Furthermore, on the hole transport layer 112, 7-[4-(10-F, represented by the above structural formula (iii) is added. Phenyl-9-antryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA) and N,N'-bis(3-methylphenicol) represented by the above structural formula (iv) (Lu)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl] -Pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn) and by weight ratio 1: 25nm so that the value becomes 0.05 (=cgDBCzPA:1,6mMemFLPAPrn) A light-emitting layer 113 was formed by co-deposition.

[0208] Subsequently, the first electron transport layer 114-1 is placed on the light-emitting layer 113, represented by the above structural formula (v). 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f After depositing a 10 nm film of [h]quinoxaline (abbreviation: 2mDBTBPDBq-II), As electron transport layer 114-2 of 2, bathophenanthroline represented by the above structural formula (vi) ( A film (abbreviated as BPhen) was deposited to a thickness of 15 nm.

[0209] After forming the first electron transport layer 114-1 and the second electron transport layer 114-2, lithium fluoride LiF (LiF) was deposited to a thickness of 1 nm, and aluminum was deposited to a thickness of 200 nm. The cathode 102 was formed by vapor deposition in a certain manner, and the light-emitting element 1 of this embodiment was fabricated.

[0210] (Method for fabricating comparative light-emitting element 1) Comparative light-emitting element 1 is 2mDBTBPDBq-II in the first electron transport layer of light-emitting element 1. The device was fabricated in the same way as light-emitting element 1, except that it was replaced with cgDBCzPA.

[0211] The element structures of light-emitting element 1 and comparative light-emitting element 1 are summarized in the table below.

[0212] [Table 1]

[0213] The light-emitting element 1 and the comparative light-emitting element 1 were placed in a glove box under a nitrogen atmosphere. The process of sealing the element with a glass substrate to prevent it from being exposed to the atmosphere (applying a sealing material around the element). Then, after UV treatment and heat treatment at 80°C for 1 hour during sealing, these light-emitting elements undergo initial characteristics Measurements were taken to assess performance and reliability. The measurements were performed at room temperature (in an atmosphere maintained at 25°C). .

[0214] Figure 14 shows the luminance-current density characteristics of light-emitting element 1 and comparative light-emitting element 1, and the current efficiency-luminance characteristics. Figure 15 shows the luminance-voltage characteristics, Figure 16 shows the current-voltage characteristics, and Figure 17 shows the external quantum efficiency-luminance. The characteristics are shown in Figure 18, and the emission spectra are shown in Figure 19. Furthermore, the 1000 cd / m² values ​​for each light-emitting element are shown in Figure 18. m 2 Table 2 shows the main characteristics of the vicinity.

[0215] [Table 2]

[0216] From Figures 14 to 19 and Table 2, it can be seen that all of the light-emitting elements are blue light-emitting elements with good characteristics. That's what I found out.

[0217] Additionally, the initial brightness is 5000 cd / m². 2 And, with respect to the driving time under the condition of constant current density Figure 20 shows a graph representing the change in brightness of the light-emitting element. As shown in Figure 20, one of the present inventions The light-emitting element 1, which is a light-emitting element of the embodiment, exhibits a lower brightness due to the accumulation of operating time compared to the comparative light-emitting element 1. It was found to be a light-emitting element with a small base and a good lifespan.

[0218] Furthermore, the light-emitting element 1 uses HAT-CN, an organic acceptor, in its hole injection layer. As shown in Figures 15 and 18, it can be seen that the decrease in brightness in the high-brightness region is small. In other words, the configuration of the light-emitting element 1, which is the light-emitting element in this embodiment, is a roll-off of the efficiency on the high-brightness side. This structure can reduce emissions and maintain high efficiency even when emitting light at high brightness. It can be said that it is a success.

[0219] From the results of cyclic voltammetry (CV) measurements, cgDBCzPA and 2mDBTB were found. The LUMO levels of PDBq-II and BPhen are -2.74 eV and -2.74 eV, respectively. It is estimated to be 94 eV and -2.63 eV. Therefore, the light-emitting element 1 is one aspect of the present invention. It appears that way.

[0220] Here, the HOMO level of PCBBiF is estimated to be -5.36 eV based on the results of CV measurements. Because it is present and the HOMO level is relatively high (-5.4eV or higher), HAT-CN Electron extraction by this method is effective. However, the anthracene induction used in the light-emitting layer... The HOMO level of the conductor cgDBCzPA is estimated to be -5.69 eV from similar CV measurements. Because it accumulates, light is emitted from the hole transport layer in both the light-emitting element 1 and the comparative light-emitting element 1. The injection barrier into the host material of the layer is large at 0.33 eV. Therefore, in comparative light-emitting element 1, The element has too many sub-elements, resulting in a large roll-off and reduced lifespan. In the light-emitting element 1, the low hole injection capability of this organic acceptor is addressed by one aspect of the present invention. Because the components are complemented, a small roll-off and a long lifespan can be achieved. [Examples]

[0221] In this embodiment, the light-emitting element 2 of one aspect of the present invention described in Embodiment 1 is described in the present invention. The results of a comparison with a comparative light-emitting element 2 having a different configuration from one embodiment of the light-emitting element are shown. Light-emitting element 2 and comparison light-emitting element 2 have a configuration that differs only in the material of the first electron transport layer. The structural formulas of the organic compounds used in the optical element 2 and the comparative light-emitting element 2 are shown below.

[0222] [ka]

[0223] (Method for fabricating light-emitting element 2) First, indium tin oxide (ITSO) containing silicon oxide is sputtered onto a glass substrate. A film was deposited using the 3D method to form the anode 101. The film thickness was 110 nm, and the electrode area was The dimensions were set to 2mm x 2mm.

[0224] Next, as a pretreatment for forming light-emitting elements on the substrate, the substrate surface is washed with water, and 200 After firing at ℃ for 1 hour, UV ozone treatment was performed for 370 seconds.

[0225] Then, 10 -4 A substrate is introduced into a vacuum deposition apparatus where the internal pressure is reduced to approximately Pa, and then vacuum deposition is performed. After vacuum firing at 170°C for 30 minutes in the heating chamber of the apparatus, the substrate is left for approximately 30 minutes. It was allowed to cool.

[0226] Next, the substrate on which the anode 101 is formed is turned so that the surface with the anode 101 is facing downwards. It is fixed to a substrate holder installed inside the air deposition apparatus, 10 -4 After reducing the pressure to approximately Pa, On electrode 101, 2, 3, 6, represented by the above structural formula (i), are deposited by a resistive heating deposition method. 7,10,11-Hexacyano-1,4,5,8,9,12-Hexazatriphenylene A hole injection layer 111 was formed by depositing (abbreviated as HAT-CN) at a 10 nm depth.

[0227] Next, on the hole injection layer 111, N-(1,1'-bipheny represented by the above structural formula (ii) is injected. Lu-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazole- 3-yl)phenyl]-9H-fluoren-2-amine (abbreviation: PCBBiF) 10n A film was deposited to a thickness of m, forming a hole transport layer 112.

[0228] Furthermore, on the hole transport layer 112, 7-[4-(10-F, represented by the above structural formula (iii) is added. Phenyl-9-antryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA) and N,N'-bis(3-methylphenicol) represented by the above structural formula (iv) (Lu)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl] -Pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn) and by weight ratio 1: 25nm so that the value becomes 0.05 (=cgDBCzPA:1,6mMemFLPAPrn) A light-emitting layer 113 was formed by co-deposition.

[0229] Subsequently, the first electron transport layer 114-1 is placed on the light-emitting layer 113, represented by the above structural formula (v). 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f After depositing a 10 nm film of [h]quinoxaline (abbreviation: 2mDBTBPDBq-II), The electron transport layer 114-2 of 2 is represented by the above structural formula (vii) and is 2,9-bis(naphtha). Len-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPh) A film was deposited using (en) to a thickness of 15 nm.

[0230] After forming the first electron transport layer 114-1 and the second electron transport layer 114-2, lithium fluoride LiF (LiF) was deposited to a thickness of 1 nm, and aluminum was deposited to a thickness of 200 nm. The cathode 102 was formed by vapor deposition in a certain manner, and the light-emitting element 2 of this embodiment was fabricated.

[0231] (Method for fabricating comparative light-emitting element 2) Comparative light-emitting element 2 is 2mDBTBPDBq-II in the first electron transport layer of light-emitting element 2. The device was fabricated in the same way as light-emitting element 2, except that it was replaced with cgDBCzPA.

[0232] The element structures of light-emitting element 2 and comparative light-emitting element 2 are summarized in the table below.

[0233] [Table 3]

[0234] The light-emitting element 2 and the comparative light-emitting element 2 were placed in a glove box under a nitrogen atmosphere. The process of sealing the element with a glass substrate to prevent it from being exposed to the atmosphere (applying a sealing material around the element). Then, after UV treatment and heat treatment at 80°C for 1 hour during sealing, these light-emitting elements undergo initial characteristics Measurements were taken to assess performance and reliability. The measurements were performed at room temperature (in an atmosphere maintained at 25°C). .

[0235] Figure 21 shows the luminance-current density characteristics of light-emitting element 2 and comparison light-emitting element 2, and the current efficiency-luminance characteristics. Figure 22 shows the luminance-voltage characteristics, Figure 23 shows the current-voltage characteristics, and Figure 24 shows the external quantum efficiency-luminance. The intensity characteristics are shown in Figure 25, and the emission spectra are shown in Figure 26. Furthermore, the 1000 cd / m³ values ​​for each light-emitting element are shown in Figure 25. m 2 Table 4 shows the main characteristics of the vicinity.

[0236] [Table 4]

[0237] From Figures 21 to 26 and Table 4, it can be seen that all of the light-emitting elements are blue light-emitting elements with good characteristics. That's what I found out.

[0238] Additionally, the initial brightness is 5000 cd / m². 2 And, with respect to the driving time under the condition of constant current density Figure 27 shows a graph representing the change in brightness of the light-emitting element. As shown in Figure 27, the present invention The light-emitting element 2 exhibits less brightness reduction with accumulated operating time compared to the comparative light-emitting element 2. It was found to be a light-emitting element with a good lifespan.

[0239] Furthermore, the light-emitting element 2 uses HAT-CN, an organic acceptor, in its hole injection layer. Therefore, as shown in Figures 22 and 25, it can be seen that the decrease in brightness in the high-brightness region is small. In other words, the configuration of the light-emitting element 2, which is the light-emitting element in this embodiment, is a roll of efficiency on the high brightness side. It can reduce power outages and maintain high efficiency even when emitting light at high brightness. It can be described as a structure.

[0240] From the results of cyclic voltammetry (CV) measurements, cgDBCzPA and 2mDBTB were found. The LUMO levels of PDBq-II and NBPhen are -2.74 eV and -2 eV, respectively. It is estimated to be 0.94 eV and -2.83 eV. Therefore, the light-emitting element 2 is one of the present inventions. It is a manner.

[0241] Here, the HOMO level of PCBBiF is estimated to be -5.36 eV based on the results of CV measurements. Because it is present and the HOMO level is relatively high (-5.4eV or higher), HAT-CN Electron extraction by this method is effective. However, the anthracene induction used in the light-emitting layer... The HOMO level of the conductor cgDBCzPA is estimated to be -5.69 eV from similar CV measurements. Because it accumulates, light is emitted from the hole transport layer in both the light-emitting element 2 and the comparison light-emitting element 2. The injection barrier into the host material of the layer is large at 0.33 eV. Therefore, in comparative light-emitting element 2, The element has too many sub-elements, resulting in a large roll-off and reduced lifespan. In the light-emitting element 2, the low hole injection capability of this organic acceptor is addressed by one aspect of the present invention. Because the components are complemented, a small roll-off and a long lifespan can be achieved. [Examples]

[0242] In this embodiment, the light-emitting element 3 of one aspect of the present invention described in Embodiment 1 is described in the present invention. The results of a comparison with a comparative light-emitting element 3 having a different configuration from one embodiment of the light-emitting element are shown. The light-emitting element 3 and the comparative light-emitting element 3 have a configuration that differs only in the material of the first electron transport layer. The structural formulas of the organic compounds used in the optical element 3 and the comparative light-emitting element 3 are shown below.

[0243] [ka]

[0244] (Method for fabricating the light-emitting element 3) First, indium tin oxide (ITSO) containing silicon oxide is sputtered onto a glass substrate. A film was deposited using the 3D method to form the anode 101. The film thickness was 110 nm, and the electrode area was The dimensions were set to 2mm x 2mm.

[0245] Next, as a pretreatment for forming light-emitting elements on the substrate, the substrate surface is washed with water, and 200 After firing at ℃ for 1 hour, UV ozone treatment was performed for 370 seconds.

[0246] Then, 10 -4 A substrate is introduced into a vacuum deposition apparatus where the internal pressure is reduced to approximately Pa, and then vacuum deposition is performed. After vacuum firing at 170°C for 30 minutes in the heating chamber of the apparatus, the substrate is left for approximately 30 minutes. It was allowed to cool.

[0247] Next, the substrate on which the anode 101 is formed is turned so that the surface with the anode 101 is facing downwards. It is fixed to a substrate holder installed inside the air deposition apparatus, 10 -4 After reducing the pressure to approximately Pa, On electrode 101, 3-[ represented by the above structural formula (viii) is deposited by a vapor deposition method using resistance heating. 4-(9-phenanthryl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: By co-depositing PCPPn and molybdenum(VI) oxide, a hole injection layer 111 is formed. It was done. The film thickness was 10 nm, and the ratio of PCPPn to molybdenum oxide was 4 by weight. The ratio was adjusted to :2 (=PCPPn: molybdenum oxide).

[0248] Next, PCPPn is deposited on the hole injection layer 111 to a thickness of 20 nm, and hole injection A deposition layer 112 was formed.

[0249] Furthermore, on the hole transport layer 112, 7-[4-(10-F, represented by the above structural formula (iii) is added. Phenyl-9-antryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA) and N,N'-bis(3-methylphenicol) represented by the above structural formula (iv) (Lu)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl] -Pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn) and by weight ratio 1: 25nm so that the value becomes 0.03 (=cgDBCzPA:1,6mMemFLPAPrn) A light-emitting layer 113 was formed by co-deposition.

[0250] Subsequently, the first electron transport layer 114-1 is placed on the light-emitting layer 113, represented by the above structural formula (v). 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f After depositing a 10 nm film of [h]quinoxaline (abbreviation: 2mDBTBPDBq-II), The electron transport layer 114-2 of 2 is represented by the above structural formula (ix) 2,2'-(pyridine- 2,6-diyl)bis(4,6-diphenylpyrimidine) (abbreviation: 2,6(P2Pm)2 A film of Py was deposited to a thickness of 15 nm.

[0251] After forming the first electron transport layer 114-1 and the second electron transport layer 114-2, lithium fluoride LiF (LiF) was deposited to a thickness of 1 nm, and aluminum was deposited to a thickness of 200 nm. The cathode 102 was formed by vapor deposition in a certain manner, and the light-emitting element 3 of this embodiment was fabricated.

[0252] (Method for fabricating comparative light-emitting element 3) Comparative light-emitting element 3 is 2mDBTBPDBq-II in the first electron transport layer of light-emitting element 3. The device was fabricated in the same way as light-emitting element 3, except that cgDBCzPA was replaced with cgDBCzPA.

[0253] The element structures of light-emitting element 3 and comparative light-emitting element 3 are summarized in the table below.

[0254] [Table 5]

[0255] The light-emitting element 3 and the comparative light-emitting element 3 were placed in a glove box under a nitrogen atmosphere. The process of sealing the element with a glass substrate to prevent it from being exposed to the atmosphere (applying a sealing material around the element). Then, after UV treatment and heat treatment at 80°C for 1 hour during sealing, these light-emitting elements undergo initial characteristics Measurements were taken to assess performance and reliability. The measurements were performed at room temperature (in an atmosphere maintained at 25°C). .

[0256] Figure 28 shows the brightness-current density characteristics of light-emitting element 3 and comparative light-emitting element 3, and the current efficiency-brightness characteristics. Figure 29 shows the luminance-voltage characteristics, Figure 30 shows the current-voltage characteristics, and Figure 31 shows the external quantum efficiency-luminance. The characteristics are shown in Figure 32, and the emission spectra are shown in Figure 33. Furthermore, the 1000 cd / m³ values ​​for each light-emitting element are shown in Figure 33. m 2 Table 6 shows the main characteristics of the vicinity.

[0257] [Table 6]

[0258] As shown in Figures 28 to 33 and Table 6, all of the light-emitting elements were blue light-emitting elements with good characteristics. However, the light-emitting element 3 in particular exceeds an external quantum efficiency of 12% (assuming Lambertsian light distribution). It was found to be a highly efficient light-emitting element.

[0259] Additionally, the initial brightness is 5000 cd / m². 2 And, with respect to the driving time under the condition of constant current density Figure 34 shows a graph representing the change in brightness of the light-emitting element. As shown in Figure 34, one of the present inventions The light-emitting element 3 of the embodiment exhibits a lower brightness due to the accumulation of operating time compared to the comparative light-emitting element 3. It was found to be a light-emitting element with a small base and a good lifespan.

[0260] From the results of cyclic voltammetry (CV) measurements, cgDBCzPA and 2mDBTB were found. The LUMO levels of PDBq-II and 2,6(P2Pm)2Py are -2.7, respectively. It is estimated to be 4eV, -2.94eV, and -2.78eV. Therefore, the light-emitting element 3 This is one aspect of the present invention.

[0261] Here, in this light-emitting element 3, the hole injection layer is a hole transport material with acceptor properties A composite material containing a substance is used. The hole-transporting substance used in this hole injection layer This is PCPPn, which is also used in the hole transport layer, but the HOMO level of this material is measured by CV. According to the specifications, the voltage is deep at -5.80 eV. Therefore, PCPPn is the host material for the emissive layer. The hole injection capability into cgDBCzPA (HOMO is -5.69eV) is good, but the positive from the anode... Pore ​​injection is generally considered difficult. However, in the light-emitting element 3, the acceptor material undergoes transition Because it uses a metal oxide, it exhibits hole transport properties with a HOMO level lower than -5.4 eV (deeper). It also exhibits acceptor properties for materials (at least it can extract electrons by applying an electric field). (This is possible.) As a result, hole injection and transport from the anode to the hole injection layer, hole transport layer, and light emission layer are possible. This is carried out smoothly. By combining this hole injection layer with one aspect of the present invention, a light-emitting element is produced. 3 achieves not only a low drive voltage but also an unexpectedly high external quantum efficiency and long lifespan. This is one of its major characteristics. [Examples]

[0262] In this embodiment, the light-emitting element 4 according to one aspect of the present invention described in Embodiment 1 is described in the present invention. The results of a comparison with a comparative light-emitting element 4 having a different configuration from one embodiment of the light-emitting element are shown. The light-emitting element 4 and the comparison light-emitting element 4 have a configuration that differs only in the material of the first electron transport layer. The structural formulas of the organic compounds used in the optical element 4 and the comparative light-emitting element 4 are shown below.

[0263] [ka]

[0264] (Method for fabricating the light-emitting element 4) First, indium tin oxide (ITSO) containing silicon oxide is sputtered onto a glass substrate. A film was deposited using the 3D method to form the anode 101. The film thickness was 110 nm, and the electrode area was The dimensions were set to 2mm x 2mm.

[0265] Next, as a pretreatment for forming light-emitting elements on the substrate, the substrate surface is washed with water, and 200 After firing at ℃ for 1 hour, UV ozone treatment was performed for 370 seconds.

[0266] Then, 10 -4 A substrate is introduced into a vacuum deposition apparatus where the internal pressure is reduced to approximately Pa, and then vacuum deposition is performed. After vacuum firing at 170°C for 30 minutes in the heating chamber of the apparatus, the substrate is left for approximately 30 minutes. It was allowed to cool.

[0267] Next, the substrate on which the anode 101 is formed is turned so that the surface with the anode 101 is facing downwards. It is fixed to a substrate holder installed inside the air deposition apparatus, 10 -4 After reducing the pressure to approximately Pa, On electrode 101, 3-[ represented by the above structural formula (viii) is deposited by a vapor deposition method using resistance heating. 4-(9-phenanthryl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: By co-depositing PCPPn and molybdenum(VI) oxide, a hole injection layer 111 is formed. It was done. The film thickness was 10 nm, and the ratio of PCPPn to molybdenum oxide was 4 by weight. The ratio was adjusted to :2 (=PCPPn: molybdenum oxide).

[0268] Next, PCPPn is deposited on the hole injection layer 111 to a thickness of 30 nm, and hole injection A deposition layer 112 was formed.

[0269] Furthermore, on the hole transport layer 112, 7-[4-(10-F, represented by the above structural formula (iii) is added. Phenyl-9-antryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA) and N,N'-bis(3-methylphenicol) represented by the above structural formula (iv) (Lu)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl] -Pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn) and by weight ratio 1: 25nm so that the value becomes 0.03 (=cgDBCzPA:1,6mMemFLPAPrn) A light-emitting layer 113 was formed by co-deposition.

[0270] Subsequently, the first electron transport layer 114-1 is placed on the light-emitting layer 113, represented by the above structural formula (v). 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f After depositing a 10 nm film of [h]quinoxaline (abbreviation: 2mDBTBPDBq-II), The electron transport layer 114-2 of 2 is represented by the above structural formula (vii) and is 2,9-bis(naphtha). Len-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPh) A film was deposited using (en) to a thickness of 15 nm.

[0271] After forming the first electron transport layer 114-1 and the second electron transport layer 114-2, lithium fluoride LiF (LiF) was deposited to a thickness of 1 nm, and aluminum was deposited to a thickness of 200 nm. The cathode 102 was formed by vapor deposition in a manner that allowed the light-emitting element 4 of this embodiment to be fabricated.

[0272] (Method for fabricating comparative light-emitting element 4) The comparative light-emitting element 4 has 2mDBTBPDBq-II in the first electron transport layer of the light-emitting element 4. The device was fabricated in the same way as light-emitting element 4, except that it was replaced with cgDBCzPA.

[0273] The element structures of the light-emitting element 4 and the comparative light-emitting element 4 are summarized in the table below.

[0274] [Table 7]

[0275] The light-emitting element 4 and the comparative light-emitting element 4 were placed in a glove box under a nitrogen atmosphere. The process of sealing the element with a glass substrate to prevent it from being exposed to the atmosphere (applying a sealing material around the element). Then, after UV treatment and heat treatment at 80°C for 1 hour during sealing, these light-emitting elements undergo initial characteristics Measurements were taken to assess performance and reliability. The measurements were performed at room temperature (in an atmosphere maintained at 25°C). .

[0276] Figure 35 shows the luminance-current density characteristics of light-emitting element 4 and comparative light-emitting element 4, and the current efficiency-luminance characteristics. Figure 36 shows the luminance-voltage characteristics, Figure 37 shows the current-voltage characteristics, and Figure 38 shows the external quantum efficiency-luminance. The intensity characteristics are shown in Figure 39, and the emission spectra are shown in Figure 40. Furthermore, the 1000 cd / m³ values ​​for each light-emitting element are shown in Figure 40. m 2 Table 8 shows the main characteristics of the vicinity.

[0277] [Table 8]

[0278] Figures 35 to 40 and Table 8 show that both light-emitting elements were blue light-emitting elements with good characteristics. However, the light-emitting element 4 in particular has an external quantum efficiency of 13.7% (assuming Lambertsian light distribution). It was found to be a light-emitting element that exceeds expectations and is extremely efficient.

[0279] Additionally, the initial brightness is 5000 cd / m². 2 And, with respect to the driving time under the condition of constant current density Figure 41 shows a graph representing the change in brightness of the light-emitting element. As shown in Figure 41, the present invention The light-emitting element 4 of the embodiment exhibits lower brightness due to the accumulation of operating time compared to the comparative light-emitting element 4. It was found to be a light-emitting element with a small base and a good lifespan.

[0280] From the results of cyclic voltammetry (CV) measurements, cgDBCzPA and 2mDBTB were found. The LUMO levels of PDBq-II and NBPhen are -2.74 eV and -2 eV, respectively. It is estimated to be 0.94 eV and -2.83 eV. Therefore, the light-emitting element 4 is one of the present inventions. It is a manner.

[0281] Here, in this light-emitting element 4, the hole injection layer is made of a hole-transporting material with acceptor properties. A composite material containing a substance is used. The hole-transporting substance used in this hole injection layer This is PCPPn, which is also used in the hole transport layer, but the HOMO level of this material is measured by CV. According to the specifications, the voltage is deep at -5.80 eV. Therefore, PCPPn is the host material for the emissive layer. The hole injection capability into cgDBCzPA (HOMO is -5.69eV) is good, but the positive from the anode... Pore ​​injection is generally considered difficult. However, in the light-emitting element 4, the acceptor material undergoes transition. Because it uses a metal oxide, it exhibits hole transport properties with a HOMO level lower than -5.4 eV (deeper). It also exhibits acceptor properties for materials (at least it can extract electrons by applying an electric field). (This is possible.) As a result, hole injection and transport from the anode to the hole injection layer, hole transport layer, and light emission layer are possible. This is carried out smoothly. By combining this hole injection layer with one aspect of the present invention, a light-emitting element is produced. 4 achieves not only a low drive voltage but also an unexpectedly high external quantum efficiency and long lifespan. This is one of its major characteristics. [Examples]

[0282] A table is provided showing compounds that can be suitably used in a light-emitting element according to one embodiment of the present invention. (Light-emitting layer) The following compounds having a condensed aromatic ring skeleton with 3 to 6 rings are suitable as host materials for N in Table 9. Listed in o.1 to No.13. Also, lowering the LUMO level suitable for the first electron transport layer. The compound groups are No. 14 to No. 35 in Table 10, and the compound group suitable for the second electron transport layer (No. Compared to the group of compounds suitable for electron transport layer 1, these compounds tend to have relatively high LUMO levels. The compounds are listed in Table 11, Nos. 36 to 46. The molecular structure of each compound is also shown below. The following is shown together. In each table, EmL refers to the light-emitting layer, ETL1 refers to the first electron transport layer, and ETL2 refers to the first electron transport layer. This represents the electron transport layer 2. Note that the LUMO level is determined by cyclic voltammetry (C), which will be discussed later. V) Calculated by measurement.

[0283] [Table 9]

[0284] [ka]

[0285] [ka]

[0286] [Table 10]

[0287] [ka]

[0288] [ka]

[0289] [ka]

[0290] [Table 11]

[0291] [ka]

[0292] [ka]

[0293] From this table, for example, the LUMO level of a compound with an anthracene skeleton is -2.7 eV earlier. It can be seen that it is later. Therefore, the host material of the luminescent layer has an anthracene skeleton. When using a compound, the group of compounds having a LUMO level lower than that compound is called the first group. It can be used as an electron transport layer, and any of No. 14 to No. 35 can be used. Yes, however, since it is preferable that the energy difference of the LUMO levels be within 0.3 eV, Dibenzoquinoxaline skeletons and dibenzoquinazoline skeletons are more common in the -2.8 to -2.9 eV range. Compounds having a pyrimidine skeleton are particularly preferred. In this case, the second electron transport layer and By using compounds No. 36 to No. 46, a light-emitting element according to one embodiment of the present invention can be fabricated. It is possible.

[0294] The present invention also applies in the same manner when a compound having a different skeleton is used as the host material for the light-emitting layer. A light-emitting element of one form can be fabricated. For example, if the host material of the light-emitting layer is tetra When using compounds with a cene skeleton, compounds with a tetracene skeleton are relatively LUMO Because the value is low, not all of No. 14 to No. 36 are suitable as the first electron transport layer. However, for example, fused ring pyrazine compounds and fused ring triazine compounds are first electron It can be seen that a light-emitting element according to one aspect of the present invention can be fabricated by using it as a transport layer.

[0295] As can be seen from the table, it has a phenanthroline skeleton, a bipyridine skeleton, and a pyridine skeleton. Because the compound has a relatively high LUMO level among electron-transporting compounds, the second electron These compounds are suitable as transport layers. Furthermore, when these compounds are used in contact with the cathode, they are suitable for transporting from the cathode. Because it exhibits excellent electron injection properties, it is also suitable as a second electron transport layer.

[0296] Here, we will explain the method of cyclic voltammetry (CV) measurement. CV measurement This includes an electrochemical analyzer (manufactured by BAS Corporation, model number: ALS Model 600A). Alternatively, 600°C was used.

[0297] Furthermore, the solution used in CV measurement is dehydrated dimethylformamide (DMF) as the solvent. (Aldrich, 99.8%, catalog number; 227056-12) used, with supporting electrolytic capacitors. The substance is tetra-n-butylammonium perchlorate (electrochemical Grade, manufactured by Wako Pure Chemical Industries, Ltd., manufacturer code: 043999, CAS No.: 1923 Dissolve (-70-2) to a concentration of 100 mmol / L, and then add the sample to be measured to 2 ml. Prepare the solution by dissolving it to a concentration of mol / L, add it to the electrochemical cell, and set each electrode. After that, the electrodes were degassed for about 30 minutes using argon bubbling. The electrodes used also had working electrodes and For the main electrode, a platinum electrode (PTE platinum electrode manufactured by BAS Corporation) is used, and for the auxiliary electrode, white A gold electrode (manufactured by BAS Co., Ltd., Pt counter electrode) is used as the reference electrode, and a non-aqueous electrode is used. Reference electrode in a medium (manufactured by BAS Corporation), RE-7 non-aqueous solvent reference electrode (Ag / Ag+ The following parameters were used: ) and the scan speed during measurement was set to room temperature (20-25°C). The voltage was standardized to 0.1 V / sec. In this embodiment, the reference electrode's voltage relative to the vacuum level was set to 0.1 V / sec. The initial energy was assumed to be -4.94 eV.

[0298] The LUMO level (reduction potential) and HOMO level (oxidation potential) were determined from the CV measurement results. The LUMO level is the oxidation peak potential (from the reducing side to the neutral side) E pc [V] and reduction peak potential (From neutral to reducing) E pa From [V], half-wave potential (E pa and E pc The potential between the two is (E pa +E pc The potential energy of the reference electrode relative to the vacuum level is calculated as ) / 2[V]. This was determined by subtracting this half-wave potential from the energy (-4.94 eV). The HOMO level is Oxidation peak potential (from neutral to oxidized side) Epa [V] and reduction peak potential (from oxidized to neutral) (Interval) E pc From [V], half-wave potential (E pa and E pc (The potential between the two) is (E pa +E pc ) The potential energy of the reference electrode relative to the vacuum level is calculated as (-4.94) / 2[V]. This was obtained by subtracting the half-wave potential from the eV value. [Explanation of Symbols]

[0299] 101 Anode 102 Cathode 103 EL layer 111 Hole injection layer 112 Hole transport layer 113 Emitting layer 114 Electron transport layer 114-1 First electron transport layer 114-2 Second electron transport layer 115 Electron injection layer 116 Charge generation layer 117 P type layer 118 Electron relay layer 119 Electron injection buffer layer 400 circuit boards 401 First electrode 403 EL layer 404 Second electrode 405 sealant 406 Sealant 407 Sealing substrate 412 pads 420 IC chips 501 First electrode 502 Second electrode 511 First light-emitting unit 512 Second light-emitting unit 513 Charge generation layer 601 Drive circuit section (source line drive circuit) 602 pixel section 603 Drive circuit section (gate wire drive circuit) 604 Sealing substrate 605 Sealant 607 Space 608 Wiring 609 FPC (Flexible Printed Circuit) 610 element substrate 611 Switching FET 612 Current-Controlled FET 613 First electrode 614 Insulators 616 EL layer 617 Second electrode 618 Light-emitting element 901 cabinet 902 Liquid Crystal Layer 903 Backlight Unit 904 cabinet 905 Driver IC 906 terminal 951 circuit board 952 Electrode 953 Insulating layer 954 Partition layer 955 EL layer 956 Electrode 1001 circuit board 1002 Underlying insulating film 1003 Gate Insulator 10:06 Guard Station 1007 🙏 1008 Gate 1020 First interlayer insulating film 1021 Second interlayer insulating film 1022 Electrode 1024W First electrode 1024R First electrode 1024G First electrode 1024B First electrode 1025 Bulkhead 1028 EL layer 1029 Second electrode 1031 Sealing substrate 1032 Sealant 1033 Transparent base material 1034R Red colored layer 1034G Green colored layer 1034B Blue colored layer 1035 Black Matrix 1036 Overcoat layer 1037 Third interlayer insulating film 1040 pixel section 1041 Drive circuit section 1042 Peripheral area 2001 cabinet 2002 light source 3001 Lighting device 5000 display area 5001 Display area 5002 Display area 5003 Display area 5004 Display area 5005 Display area 7101 enclosure 7103 Display section 7105 Stand 7107 Display section 7109 Operation Keys 7110 Remote Control Unit 7201 Main Unit 7202 enclosure 7203 Display section 7204 Keyboard 7205 External connection port 7206 Pointing device 7210 Second display unit 7301 enclosure 7302 enclosure 7303 Connection section 7304 Display section 7305 Display section 7306 Speaker section 7307 Recording media insertion section 7308 LED Lamp 7309 Operation Keys 7310 Connection terminal 7311 Sensor 7401 enclosure 7402 Display section 7403 Operation Buttons 7404 External connection port 7405 Speaker 7406 Microphone 7400 mobile phones 9033 Fastener 9034 Switch 9035 Power switch 9036 Switch 9310 Mobile Information Terminal 9311 Display Panel 9312 Display area 9313 Hinge 9315 enclosure 9630 cabinet 9631 Display section 9631a Display section 9631b Display section 9632a Touch panel area 9632b Touch panel area 9633 Solar Cell 9634 Charge / Discharge Control Circuit 9635 Battery 9636 DC-DC converter 9637 Operation Keys 9638 converter 9639 button

Claims

1. Having an anode and a cathode, A light-emitting element having a first light-emitting layer, a first electron transport layer, and a second electron transport layer between the anode and the cathode, The first light-emitting layer is located between the anode and the first electron transport layer. The first electron transport layer is located between the first light-emitting layer and the second electron transport layer. The second electron transport layer has a region in contact with the cathode, The cathode comprises one of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound. The first light-emitting layer comprises a fluorescent light-emitting material and a host material, The first electron transport layer has a first material, The second electron transport layer comprises a second material different from the first material. The LUMO level of the host material is higher than that of the first material. The host material is a substance containing an anthracene skeleton, The first material is a substance containing a triazine skeleton, The second material is a light-emitting element containing a six-membered nitrogen-containing heteroaromatic ring skeleton.

2. Having an anode and a cathode, A light-emitting element having a first light-emitting layer, a first electron transport layer, and a second electron transport layer between the anode and the cathode, The first light-emitting layer is located between the anode and the first electron transport layer. The first electron transport layer is located between the first light-emitting layer and the second electron transport layer. The second electron transport layer is located between the first electron transport layer and the cathode. The cathode comprises one of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound. The first light-emitting layer comprises a fluorescent light-emitting material and a host material, The first electron transport layer has a first material, The second electron transport layer comprises a second material different from the first material. The LUMO level of the host material is higher than that of the first material. The difference between the LUMO level of the host material and the LUMO level of the first material is within 0.3 eV. The host material is a substance containing an anthracene skeleton, The first material is a substance containing a triazine skeleton, The second material is a light-emitting element containing a six-membered nitrogen-containing heteroaromatic ring skeleton.

3. Having an anode and a cathode, A light-emitting element having a hole transport layer, a first light-emitting layer, a first electron transport layer, and a second electron transport layer between the anode and the cathode, The hole transport layer is located between the anode and the first light-emitting layer. The first light-emitting layer is located between the hole transport layer and the first electron transport layer. The first electron transport layer is located between the first light-emitting layer and the second electron transport layer. The second electron transport layer is located between the first electron transport layer and the cathode. The cathode comprises one of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound. The first light-emitting layer comprises a fluorescent light-emitting material and a host material, The first electron transport layer has a first material, The second electron transport layer comprises a second material different from the first material. The hole transport layer has a third material, The LUMO level of the host material is higher than that of the first material. The host material is a substance containing an anthracene skeleton, The first material is a substance containing a triazine skeleton, The second material is a substance containing a six-membered nitrogen-containing heteroaromatic ring skeleton, The third material is a light-emitting element comprising a fluorene skeleton and a carbazole skeleton.

4. Having an anode and a cathode, A light-emitting element having a hole transport layer, a first light-emitting layer, a first electron transport layer, and a second electron transport layer between the anode and the cathode, The hole transport layer is located between the anode and the first light-emitting layer. The first light-emitting layer is located between the hole transport layer and the first electron transport layer. The first electron transport layer is located between the first light-emitting layer and the second electron transport layer. The second electron transport layer is located between the first electron transport layer and the cathode. The cathode comprises one of an alkali metal, an alkaline earth metal, an alkali metal compound, and an alkaline earth metal compound. The first light-emitting layer comprises a fluorescent light-emitting material and a host material, The first electron transport layer has a first material, The second electron transport layer comprises a second material different from the first material. The hole transport layer has a third material, The LUMO level of the host material is higher than that of the first material. The difference between the LUMO level of the host material and the LUMO level of the first material is within 0.3 eV. The host material is a substance containing an anthracene skeleton, The first material is a substance containing a triazine skeleton, The second material is a substance containing a six-membered nitrogen-containing heteroaromatic ring skeleton, The third material is a light-emitting element comprising a fluorene skeleton and a carbazole skeleton.

5. In any one of claims 2 to 4, The second electron transport layer is a light-emitting element having a region in contact with the cathode.

6. In any one of claims 1 to 5, A light-emitting element wherein the LUMO level of the second material is higher than the LUMO level of the first material.

7. In any one of claims 1 to 6, The cathode is a light-emitting element containing magnesium.

8. In any one of claims 1 to 7, It has a hole injection layer, The hole injection layer has a region in contact with the anode, A light-emitting element in which the hole injection layer contains an organic acceptor material.

9. In any one of claims 1 to 8, A light-emitting element in which the aforementioned fluorescent material emits blue light.

10. In any one of claims 1 to 9, The light-emitting element further comprises a second light-emitting layer, The second light-emitting layer comprises the fluorescent light-emitting material and the host material, wherein the light-emitting element is a light-emitting element.

11. A light-emitting device comprising a light-emitting element according to any one of claims 1 to 10, a transistor, and at least one of a substrate.

12. The light-emitting device according to claim 11, An electronic device having at least one of a sensor, an operating button, a speaker, and a microphone.

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