Light-emitting element, light-emitting device, electronic apparatus, and lighting device

Abstract

To provide a light-emitting element with low driving voltage and favorable reliability.SOLUTION: The light-emitting element includes an electron-injection layer between a cathode and a light-emitting layer. The electron-injection layer is a mixed film of a metal and an organic compound that has a function of interacting with the metal at a tridentate or tetradentate ligand, and the metal atom and the organic compound form a SOMO.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] One embodiment of the present invention relates to a light-emitting element having a novel electron-injection layer. The present invention relates to a display device, an electronic device, and a lighting device having the same.

[0002] Note that one embodiment of the present invention is not limited to the above technical fields. The technical field of one aspect of the present invention relates to an article, a method, or a manufacturing method. is a process, machine, manufacture, or composition of matter. Therefore, the technical field of one embodiment of the present invention disclosed in the present specification more specifically relates to Examples of the semiconductor device include a semiconductor device, a display device, a liquid crystal display device, a light-emitting device, a lighting device, a power storage device, a memory device, etc. Examples include devices, methods for driving them, and methods for manufacturing them. . [Background technology]

[0003] In recent years, electroluminescence (EL) The basic structure of these light-emitting devices is as follows: The device has a structure in which a layer containing a light-emitting substance (EL layer) is sandwiched between a pair of electrodes. By applying a voltage between them, the luminescent material emits light.

[0004] Since the above-mentioned light-emitting element is a self-luminous type, a display device using this element has excellent visibility and backlighting. It has the advantage of not requiring a light source and consuming little power. It also has the advantage of having a high response speed.

[0005] In general, in order to reduce the driving voltage, an electron injection layer is provided between the cathode and the light-emitting layer. The electron injection layer reduces the electron injection barrier between the cathode and the EL layer, and thus lithium (L i) and calcium (Ca), and other alkali metals and alkaline earth metals Metals with small functions and their compounds are used (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-102175 A Summary of the Invention [Problem to be solved by the invention]

[0007] Metals with low work functions and their compounds are highly reactive with oxygen and water, making them difficult to handle. In addition, when the metal or metal compound is used in a light-emitting device, it is affected by oxygen and water, and the light-emitting device This may result in a decrease in the light emission efficiency, an increase in the driving voltage, or a decrease in reliability. Therefore, it is less susceptible to the effects of oxygen and water, and has a small electron injection barrier between the cathode and the EL layer. There is a need to develop new implantation layers.

[0008] In view of the above-described problems, one embodiment of the present invention is to provide a light-emitting element having a low driving voltage. Another object of one embodiment of the present invention is to provide a light-emitting element having high moisture resistance. Another object of one embodiment of the present invention is to provide a light-emitting element having high oxygen resistance. Another object of one embodiment of the present invention is to provide a light-emitting element with reduced power consumption. Another object of one embodiment of the present invention is to provide a light-emitting element with high reliability. Another object of one embodiment of the present invention is to provide a novel light-emitting element. An object of one embodiment of the present invention is to provide a novel semiconductor device. In one embodiment of the present invention, an organic compound that can be used for a light-emitting element having high moisture resistance is provided. This will be the task.

[0009] Another embodiment of the present invention is an electronic device or a lighting device which has high moisture resistance and which uses the light-emitting element. Another object of the present invention is to provide a light emitting device using the light emitting element. Another object of the present invention is to provide a light-emitting device with reduced power consumption. It is an object of the present invention to provide a light emitting device having a long life using the light emitting element.

[0010] Note that the above description of the object does not preclude the existence of other objects. It is not necessary to solve all of these problems. Problems other than those mentioned above can be solved by the description of the specification, etc. It is obvious from the description of the specification, etc. that other problems can be extracted. do. [Means for solving the problem]

[0011] As described above, there is a demand for the development of light-emitting elements that have high moisture resistance and high electron injection properties. Therefore, there is a demand for the development of light-emitting elements that do not use metals with low work functions.

[0012] Therefore, one embodiment of the present invention has a light-emitting layer between an anode and a cathode, and a first layer, the first layer having a first organic compound and a metal, the metal being an element of the periodic table; The first organic compound is a substituted or unsubstituted organic compound having 1 carbon atom. The heteroaromatic rings include nitrogen, and the first organic compound includes nitrogen. The first organic compound and the metal have a function of interacting with the metal at a tridentate or tetradentate position in the substrate. The genus is SOMO (Single Occupied Molecular Orbit). It is a light-emitting element that forms a pixel.

[0013] In another embodiment of the present invention, a first light-emitting unit and a second light-emitting unit are disposed between an anode and a cathode. The composition has a light-emitting unit and a first layer between the first light-emitting unit and the second light-emitting unit. The first layer has a first organic compound and a metal, the metal being a metal of Groups 3 to 1 of the periodic table. The first organic compound is a substituted or unsubstituted compound having 1 to 30 carbon atoms. The heteroaromatic ring includes nitrogen, and the first organic compound has a structure in which the nitrogen is 3 The first organic compound and the metal form a SOMO. It is a light-emitting element.

[0014] In the above-mentioned structure, the first organic compound is preferably an organic compound represented by general formula (G0). I wish.

[0015] [ka]

[0016] In general formula (G0), A 1 , A 2 and A 3 are each independently substituted or unsubstituted A represents a heteroaromatic ring having 1 to 30 carbon atoms. 1 , A 2 and A 3 form a condensed ring with each other It's fine if it is.

[0017] In the above structure, the first organic compound is an organic compound represented by general formula (G1). It is preferable to do so.

[0018] [ka]

[0019] In general formula (G1), X 1 ~X 6 are each independently carbon (C) or nitrogen (N ), wherein carbon is hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted alkyl group having 3 cycloalkyl groups of 6 to 7, substituted or unsubstituted aromatic hydrocarbons having 6 to 25 carbon atoms a substituted or unsubstituted heteroaromatic hydrocarbon group having 3 to 30 carbon atoms, R 1 ~R 4 each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted substituted or unsubstituted cycloalkyl groups having 3 to 7 carbon atoms; Aromatic hydrocarbon groups or substituted or unsubstituted heteroaromatic hydrocarbons having 3 to 30 carbon atoms Ar represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted alkyl group having 3 a cycloalkyl group having 6 to 7 carbon atoms, an aromatic hydrocarbon group having 6 to 60 carbon atoms, or a represents a heteroaromatic hydrocarbon group having an amino acid sequence of 1 to 60;

[0020] In the above structure, the first organic compound is an organic compound represented by general formula (G2). It is preferable to do so.

[0021] [ka]

[0022] In general formula (G2), X 1 and X 2 are each independently carbon (C) or nitrogen (N ), wherein carbon is hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted alkyl group having 3 cycloalkyl groups of 6 to 7, substituted or unsubstituted aromatic hydrocarbons having 6 to 25 carbon atoms a substituted or unsubstituted heteroaromatic hydrocarbon group having 3 to 30 carbon atoms, R 1 ~R 8 each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted substituted or unsubstituted cycloalkyl groups having 3 to 7 carbon atoms; Aromatic hydrocarbon groups or substituted or unsubstituted heteroaromatic hydrocarbons having 3 to 30 carbon atoms Ar represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted alkyl group having 3 a cycloalkyl group having 6 to 7 carbon atoms, an aromatic hydrocarbon group having 6 to 60 carbon atoms, or a represents a heteroaromatic hydrocarbon group having an amino acid sequence of 1 to 60;

[0023] In the above structure, the first organic compound is any one of general formulas (G3-1) to (G3-3). It is preferable that the organic compound is one of the above.

[0024] [ka]

[0025] In general formulae (G3-1) to (G3-3), R 1 ~R 8 are each independently hydrogen an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms, or a substituted or Represents an unsubstituted heteroaromatic hydrocarbon group having 3 to 30 carbon atoms, and Ar is hydrogen, an alkyl group having 3 to 4 carbon atoms; a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms; Aromatic hydrocarbon groups with 2 to 60 carbon atoms, or heteroaromatic hydrocarbon groups with 2 to 60 carbon atoms Represents.

[0026] In the above structure, the first organic compound is any one of general formulas (G4-1) to (G4-3). It is preferable that the organic compound is one of the above.

[0027] [ka]

[0028] In the general formulae (G4-1) to (G4-3), Ar is hydrogen, Alkyl groups, substituted or unsubstituted cycloalkyl groups having 3 to 7 carbon atoms, and groups having 2 to 6 carbon atoms. Aromatic hydrocarbon groups with 0 or less carbon atoms, or heteroaromatic hydrocarbon groups with 2 to 60 carbon atoms. .

[0029] In the above structure, the first organic compound is any one of the following structural formulas (100) to (103): It is preferable that the organic compound is one of the above.

[0030] [ka]

[0031] In the above-mentioned configuration, the work function of the metal is preferably 4.0 eV or more and 5.3 eV or less. It is.

[0032] In the above-mentioned structure, the LUMO (Lowest Unoccupied Molecular Orbital) of the first organic compound is t Unoccupied Molecular Orbital) level is -3.6 eV It is preferable that the refractive index is not less than −2.3 eV.

[0033] In the above structure, the metal is preferably a transition metal, more preferably a Group 5 metal, Metals belonging to any of Groups 7, 9, or 11, and more preferably Group 11. The transition metal is preferably a metal belonging to the group A, more preferably Ag or Cu.

[0034] In the above structure, the heteroaromatic ring has a substituted or unsubstituted electron-deficient heteroaromatic ring. Preferably, the compound has any one of a pyridine ring, a diazine ring, and a triazine ring. More preferred.

[0035] In the above-mentioned structure, a second layer is further provided between the cathode and the first layer, and the second layer is an electron It is preferred to include a second organic compound having a deficient heteroaromatic ring.

[0036] In the above structure, the LUMO level of the second organic compound is higher than the energy level of the SOMO. It is preferable that the concentration is lower than the 1000 .ANG. level.

[0037] In the above structure, the first layer is a light-emitting element that does not contain an alkali metal or an alkaline earth metal. It is preferable to have one.

[0038] In the above-mentioned configuration, the molar ratio of the metal to the first organic compound in the first layer is 0. It is preferable that it be greater than .2 and less than 0.8.

[0039] In the above configuration, it is preferable that the cathode contains the same metal as the first layer.

[0040] Another embodiment of the present invention is an organic compound represented by structural formulas (200) to (203). do.

[0041] [ka]

[0042] Another embodiment of the present invention is a display device having any of the above structures and a housing or a touch sensor. Another embodiment of the present invention is an electronic device having the above-described structure. The present invention also provides a lighting device having an element and at least one of a housing and a touch sensor. One embodiment of the present invention is not limited to a light-emitting device having a light-emitting element, but also includes an electrical device having a light-emitting device. Therefore, the light-emitting device in this specification includes an image display device or a light Also, the light emitting element is connected to a connector, such as FPC (Flexib le Printed Circuit) or TCP (Tape Carrier The display module has a printed wiring board at the end of the TCP. Display module with COG (Chip On Glass) type light emitting element A display module in which an IC (integrated circuit) is directly mounted is also one embodiment of the present invention. Effect of the Invention

[0043] According to one embodiment of the present invention, a light-emitting element with low driving voltage can be provided. According to one embodiment of the present invention, a light-emitting element having high moisture resistance can be provided. In this manner, a light-emitting element having high oxygen resistance can be provided. In this way, a light-emitting element with reduced power consumption can be provided. In addition, according to one embodiment of the present invention, a novel light-emitting element having high reliability can be provided. According to one embodiment of the present invention, a novel semiconductor device can be provided. Alternatively, according to one embodiment of the present invention, a light-emitting element having high moisture resistance can be provided. It is possible to provide an organic compound capable of

[0044] According to one embodiment of the present invention, an electronic device and a lighting device which have high moisture resistance and which use the light-emitting element can be provided. According to one embodiment of the present invention, a light emitting device to which the light emitting element is applied can be provided. According to one embodiment of the present invention, a light-emitting device having reduced power consumption can be provided. It is possible to provide a long-life light-emitting device using the element.

[0045] Note that the description of these effects does not preclude the existence of other effects. It is not necessary to have all of these effects. Effects other than these are described in the specification. The disclosure of the specification, drawings, claims, etc. is self-evident, and the disclosure of the specification, drawings, claims, etc. is self-evident. From this, it is possible to extract other effects. [Brief description of the drawings]

[0046] [Figure 1] 1A and 1B are a cross-sectional schematic diagram illustrating a light-emitting element of one embodiment of the present invention and a diagram illustrating the correlation between energy levels of an electron-injection layer. [Diagram 2] 1 is a schematic cross-sectional view illustrating a light-emitting element of one embodiment of the present invention. [Diagram 3] 1 is a schematic cross-sectional view illustrating a light-emitting element of one embodiment of the present invention. [Figure 4] 1 is a schematic cross-sectional view illustrating a light-emitting element of one embodiment of the present invention. [Diagram 5] 1A and 1B are a top view and a cross-sectional schematic diagram illustrating a display device of one embodiment of the present invention. [Figure 6] 1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 7] 1A and 1B are schematic cross-sectional views illustrating a display device according to one embodiment of the present invention. [Figure 8] 1A to 1C illustrate electronic devices of one embodiment of the present invention. [Figure 9] 1A to 1C illustrate electronic devices of one embodiment of the present invention. [Figure 10]1A to 1C illustrate electronic devices of one embodiment of the present invention. [Figure 11] 1A to 1C are diagrams illustrating a lighting device according to one embodiment of the present invention. [Figure 12] FIG. 13 is a graph showing current efficiency vs. luminance characteristics of a light-emitting element in the embodiment. [Figure 13] FIG. 13 is a graph showing current-voltage characteristics of a light-emitting element in the embodiment. [Figure 14] FIG. 13 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an embodiment. [Figure 15] FIG. 2 is a graph showing electroluminescence spectra of light-emitting elements according to an embodiment of the present invention. [Figure 16] 13A to 13C are diagrams illustrating the results of a reliability test of a light-emitting element in the examples. [Figure 17] FIG. 13 is a graph showing current efficiency vs. luminance characteristics of a light-emitting element in the embodiment. [Figure 18] FIG. 13 is a graph showing current-voltage characteristics of a light-emitting element in the embodiment. [Figure 19] FIG. 13 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an embodiment. [Figure 20] FIG. 2 is a graph showing electroluminescence spectra of light-emitting elements according to an embodiment of the present invention. [Figure 21] 13A to 13C are diagrams illustrating the results of a reliability test of a light-emitting element in the examples. [Figure 22] FIG. 13 is a graph showing current efficiency vs. luminance characteristics of a light-emitting element in the embodiment. [Figure 23] FIG. 13 is a graph showing current-voltage characteristics of a light-emitting element in the embodiment. [Figure 24] FIG. 13 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an embodiment. [Diagram 25] FIG. 2 is a graph showing electroluminescence spectra of light-emitting elements according to an embodiment of the present invention. [Figure 26] FIG. 2 is a diagram illustrating an NMR spectrum of a compound according to an embodiment. [Figure 27] FIG. 2 is a diagram illustrating NMR spectra of compounds according to an embodiment. [Figure 28] FIG. 2 is a diagram illustrating NMR spectra of compounds according to an embodiment. [Figure 29] FIG. 2 is a diagram illustrating NMR spectra of compounds according to an embodiment. [Diagram 30] FIG. 2 is a diagram illustrating NMR spectra of compounds according to an embodiment. [Diagram 31] 1 is a schematic cross-sectional view illustrating a light-emitting element of one embodiment of the present invention. [Diagram 32] FIG. 13 is a graph showing current efficiency vs. luminance characteristics of a light-emitting element in the embodiment. [Diagram 33] FIG. 13 is a graph showing current-voltage characteristics of a light-emitting element in the embodiment. [Diagram 34] FIG. 13 is a graph showing power efficiency vs. luminance characteristics of a light-emitting element in the embodiment. [Diagram 35] FIG. 13 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an embodiment. [Diagram 36] FIG. 2 is a graph showing electroluminescence spectra of light-emitting elements according to an embodiment of the present invention. [Figure 37] FIG. 13 is a graph showing current efficiency vs. luminance characteristics of a light-emitting element in the embodiment. [Figure 38] FIG. 13 is a graph showing current-voltage characteristics of a light-emitting element in the embodiment. [Figure 39] FIG. 13 is a graph showing power efficiency vs. luminance characteristics of a light-emitting element in the embodiment. [Diagram 40] FIG. 13 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an embodiment. [Diagram 41] FIG. 2 is a graph showing electroluminescence spectra of light-emitting elements according to an embodiment of the present invention. [Diagram 42] FIG. 13 is a graph showing current efficiency vs. luminance characteristics of a light-emitting element in the embodiment. [Diagram 43] FIG. 13 is a graph showing current-voltage characteristics of a light-emitting element in the embodiment. [Diagram 44] FIG. 13 is a graph showing power efficiency vs. luminance characteristics of a light-emitting element in the embodiment. [Diagram 45] FIG. 13 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an embodiment. [Figure 46] FIG. 2 is a graph showing electroluminescence spectra of light-emitting elements according to an embodiment of the present invention. [Figure 47]FIG. 13 is a graph showing current efficiency vs. luminance characteristics of a light-emitting element in the embodiment. [Figure 48] FIG. 13 is a graph showing current-voltage characteristics of a light-emitting element in the embodiment. [Figure 49] FIG. 13 is a graph showing power efficiency vs. luminance characteristics of a light-emitting element in the embodiment. [Figure 50] FIG. 13 is a graph showing external quantum efficiency vs. luminance characteristics of a light-emitting element according to an embodiment. [Figure 51] FIG. 2 is a graph showing electroluminescence spectra of light-emitting elements according to an embodiment of the present invention. [Figure 52] 13A to 13C are diagrams illustrating the results of a reliability test of a light-emitting element in the examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] Hereinafter, the embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the above description, and the embodiments and details thereof are not limited to those described above without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the embodiments described below. The terms of the present disclosure are not to be construed as being limited to the content.

[0048] In addition, the position, size, range, etc. of each component shown in the drawings are not necessarily shown in order to facilitate understanding. The actual position, size, range, etc. may not be shown. The present invention is not necessarily limited to the position, size, range, etc. disclosed in the drawings, etc.

[0049] In addition, in this specification, ordinal numbers such as 1st, 2nd, etc. are used for convenience. In some cases, the order of steps or layers may not be indicated. For example, "first" may be replaced with "second" or " " can be appropriately replaced with "the third" etc. The ordinal numbers used to identify an aspect of the present invention may not match those used in the present invention. be.

[0050] In addition, in this specification and the like, when explaining the configuration of the invention using drawings, The reference numerals are used commonly among different drawings.

[0051] In addition, in this specification and the like, the terms "film" and "layer" are interchangeable. For example, the term "conductive layer" can be changed to the term "conductive film." Alternatively, for example, the term "insulating film" may be changed to "insulating layer." It may be possible to change the term to:

[0052] (Embodiment 1) In this embodiment, a light-emitting element of one embodiment of the present invention will be described below with reference to FIG.

[0053] <Configuration example 1 of light-emitting element> FIG. 1A is a schematic cross-sectional view of a light-emitting element 150 of one embodiment of the present invention.

[0054] The light emitting element 150 has a pair of electrodes (electrode 101 and electrode 102). The EL layer 100 includes at least a light-emitting layer 140 and an electron-emitting layer 142. It has an injection layer 130 .

[0055] In addition, the EL layer 100 shown in FIG. 1(A) includes a positive electrode in addition to the light-emitting layer 140 and the electron injection layer 130. It has functional layers such as a hole injection layer 111, a hole transport layer 112, and an electron transport layer 118.

[0056] In this embodiment, of the pair of electrodes, the electrode 101 is an anode, and the electrode 10 Although the description will be given assuming that 2 is a cathode, the configuration of the light emitting element 150 is not limited to this. Electrode 101 is a cathode, electrode 102 is an anode, and the layers between the electrodes are stacked in the reverse order. That is, from the anode side, a hole injection layer 111, a hole transport layer 112, and a light emitting layer The layer 140, the electron transport layer 118, and the electron injection layer 130 may be stacked in this order.

[0057] The configuration of the EL layer 100 is not limited to the configuration shown in FIG. 1(A). 140 and an electron injection layer 130, and 118, each of which may or may not be present.

[0058] In addition, the EL layer between the pair of electrodes may have a layer formed according to the required function. That is, the EL layer between the pair of electrodes reduces the hole or electron injection barrier. To improve the transportability of holes or electrons, to inhibit the transportability of holes or electrons, or to provide a The light quenching phenomenon caused by the light emitting diode may be suppressed.

[0059] The light-emitting layer 140 preferably contains a host material and a guest material (light-emitting material). stomach.

[0060] In addition, as the host material, a material having a function of transporting holes (hole transport property) is used. and materials that have the function of transporting electrons (electron transport properties) (electron transporting materials). It is preferable to use either one or both of them. Fees may also be used.

[0061] In addition, the host material may be a combination of an electron transporting material and a hole transporting material (mixed host). In this case, the carrier balance can be easily controlled by the mixture ratio. Specifically, the ratio of the electron transporting material to the hole transporting material is preferably in the range of 1:9 to 9:1 (weight ratio). Moreover, by having this configuration, the carrier balance can be easily controlled. Therefore, the carrier recombination region can be easily controlled.

[0062] In addition, a light-emitting compound may be used as the guest material. is a substance that can emit fluorescence (hereinafter also referred to as a fluorescent compound) or phosphorescence. It is preferable that the material is a material capable of emitting phosphorescent light (hereinafter also referred to as a phosphorescent compound).

[0063] In order to reduce the driving voltage of the light-emitting device, electron injection between the light-emitting layer 140 and the electrode 102 is required. Therefore, an electron injection layer is provided between the light-emitting layer 140 and the electrode 102. In the conventional light-emitting device, the electron injection layer 130 has a work function. Metallic materials containing alkali metals and alkaline earth metals with small atomic numbers are used. However, metal materials with small work functions are highly reactive with oxygen and water, and therefore, they react with oxygen and water in the light-emitting element. When a reaction with occurs, the electron injection property decreases, the light emission efficiency decreases, the driving voltage increases, and the device life is shortened. This can cause deterioration of the light emitting element, shrinkage (non-light emitting area at the edge of the light emitting part), etc. In other words, metal materials with a small work function Therefore, the deterioration of the characteristics and reliability of the light-emitting element can be suppressed. In order to achieve this, it is preferable that the light-emitting device does not contain alkali metals or alkaline earth metals. stomach.

[0064] On the other hand, metals with a large work function have low reactivity with oxygen and water, but are used for the electron injection layer 130. In this case, the electron injection barrier between the light-emitting layer 140 and the electrode 102 becomes large, so that the light-emitting element However, there are problems in that the driving voltage may become high and the light emission efficiency may decrease.

[0065] Here, the present inventors have discovered an organic compound having a function of interacting with a metal at a tridentate or tetradentate site. The SOMO is formed by interaction with metals, and the effectiveness of the combination that forms the SOMO By using a composite material of an organic compound and a metal in the electron injection layer, the electron injection from the cathode to the light-emitting layer is prevented. It has been found that a light-emitting device having a reduced wall and excellent moisture resistance can be obtained. It has been found that the electron injection layer 130 can be formed without using alkali metals and alkaline earth metals. did.

[0066] Therefore, the light-emitting element of one embodiment of the present invention has a function of interacting with a metal at a tridentate or tetradentate site. This is a light-emitting element that uses a composite material of an organic compound and a metal in the electron injection layer.

[0067] The organic compound and the metal interact to form a SOMO. The orbital originates from the unpaired electrons in the nucleus, but it is also distributed in the orbitals of organic compounds. This shows that the electron orbitals of the metal and the organic compound interact with each other. In addition, in order to efficiently interact with organic compounds and metals, the organic compounds must be prepared as interacting atoms. It is preferable to have many interacting atoms. Organic compounds with many interacting atoms have a higher interaction with metals. Since the organic compound is easy to use, it is easy to form a SOMO by mixing the organic compound with a metal. Therefore, the organic compound used in the light-emitting element of one embodiment of the present invention is a tridentate or tetradentate compound. It is preferable that the metal has a function of interacting with the metal. When a compound and a metal form a SOMO, the SOMO level tends to be high, and light is emitted from the cathode. The electron injection characteristics into the layer are good. It also interacts with metals that have a high work function, Therefore, the organic compound used in the light-emitting element of one embodiment of the present invention can form an OMO. The substance preferably has the ability to interact with metals at a tridentate or tetradentate position.

[0068] Atoms that interact with the metal include heteroatoms that have unshared electron pairs in organic compounds. Examples include oxygen (O), nitrogen (N), sulfur (S), and phosphorus (P). Nitrogen is preferred. Nitrogen has a high electronegativity and therefore easily interacts with metals. An organic compound having a function of interacting with a metal at a tridentate or tetradentate site for use in a light-emitting element according to one embodiment of the present invention. Since the compound is used in the electron injection layer, it is preferable that the compound has an electron transporting property. The compound is preferably an organic compound in which conjugation extends throughout the molecule. Here, nitrogen is not present in the organic compound. In this case, nitrogen is used in the molecule, especially in the heteroaromatic ring, because it can form conjugated bonds. By doing so, it is possible to obtain an organic compound with high carrier transport properties. The atom used is preferably nitrogen, and nitrogen is preferably present in an organic compound in a heteroaromatic ring. It is more preferable that the composition contains the metal. In addition, the heteroaromatic ring has a six-membered structure, and the organic compound has excellent carrier transport properties. It is more preferable that the ring is an even-numbered ring such as an 8-membered ring or an 8-membered ring. The shared electron pair is not involved in conjugation and is therefore more likely to interact with the metal.

[0069] The interaction between metals and organic compounds that have the ability to interact with metals at tridentate or tetradentate sites. In order to form a SOMO with the organic compound, the total number of electrons in the organic compound and the metal must be odd. Therefore, if the organic compound has an even number of electrons, the metal is In addition, when the number of electrons of the organic compound is odd, the gold Preferably, the group is an even-numbered group in the periodic table.

[0070] In addition, compounds that have the ability to interact with metals at a tridentate or tetradentate position include electron transport compounds. In addition, organic compounds that function as electron acceptors for the metal are preferred. Organic compounds are preferred.

[0071] In addition, the organic compound used in one embodiment of the present invention interacts with the metal at a tridentate or tetradentate site. Therefore, it has a high ability to interact with metals. Therefore, it is suitable for use with not only transition metals in groups 3 to 11, but also with closed-type metals. Group 12 and 13 metals having d-orbitals can also be used in one embodiment of the present invention. Metals such as gold (Au) and cobalt (Co) that have a very large work function can also be suitably used. can.

[0072] Metals with large work functions, such as those belonging to groups 3 to 13, have poor reactivity with water and oxygen. Therefore, when used in light-emitting devices, the water resistance, which is a concern when using metals with small work functions, is eliminated. The element is less susceptible to deterioration due to oxygen. Specifically, the work function of the metal is 4.0 eV or more and 5.3 e V or less, more preferably 4.2 eV to 5.0 eV, and further preferably Preferably, the energy is 4.5 eV or more and 5.0 eV or less, more preferably, 4.7 eV or more and 5.0 eV or less. With this structure, one embodiment of the present invention provides a light-emitting element having excellent moisture resistance and oxygen resistance. It is possible.

[0073] FIG. 1B is a schematic diagram of an electron-injection layer 130 in a light-emitting element of one embodiment of the present invention. The electron injection layer 130 has a compound 131 and a metal 132. The compound 131 is tridentate or tetradentate. It has the function of interacting with the metal 132 .

[0074] FIG. 1C shows an energy distribution in the electron-injection layer 130 of a light-emitting element according to one embodiment of the present invention. The diagram shows that when metal 132 is mixed with compound 131, compound 131 becomes metal 13. When compound 131 interacts with the metal atom 2, a SOMO is formed. The HOMO (Highest Occupied Molecular Orbital) formed by interacting with 132 atoms The molecular orbital (MO) level is the same as the HOMO level of the original compound 131. The same is preferable. Compound 131 is an organic compound having an electron transport function. In this case, the HOMO level of compound 131 is low, and holes are difficult to inject into compound 131. Therefore, the HOMO level formed by the interaction between compound 131 and metal 132 is the same as that of the original compound. When the HOMO level of the compound 131 is equal to that of the compound 131, the relationship between the electron injection layer 130 and the electrode 102 Since the hole injection barrier between the electron injection layer 130 and the electrode 102 is large, holes are less likely to escape from the electron injection layer 130 to the electrode 102. This is preferable because it can improve the carrier balance in the light-emitting element. OMO refers to the highest energy molecular orbital filled with electrons.

[0075] Since the SOMO is an orbital that has only one electron, when a voltage is applied to the light-emitting element 150, S The electrons in the OMO become carriers in the light-emitting element and are transported to the electron transport layer 118 and the light-emitting layer 140. In addition, electrons can be easily injected from the electrode 102 into the electron injection layer 130. Furthermore, electrons can easily flow from the electron injection layer 130 through the electron transport layer 118 to the light-emitting layer 140. In other words, the electron injection layer 130 can inject electrons into the SOMO-forming combination. By using such a material, electrons can be easily injected from the electrode 102 into the light-emitting layer 140. In addition, the SOMO level is preferably lower than the LUMO level of compound 131. Therefore, it is preferable that the LUMO level of compound 131 is high. It is preferable that the LUMO level of L1 is -3.6 eV or more and -2.3 eV or less. When an organic compound with UMO levels is mixed with a metal, SOMOs are formed by the interaction. Since the level is suitable for electron injection, the electron injection barrier from the electrode 102 to the light-emitting layer 140 can be reduced.

[0076] The HOMO and LUMO levels of organic compounds are generally measured by CV (cyclic voltammetry). It is estimated by photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, etc. When comparing values ​​between compounds, it is preferable to use values ​​estimated by the same measurement. .

[0077] Here, the above-mentioned metal is any one of Groups 3, 5, 7, 9, 11, and 13. These odd-group metals have one unpaired electron in the outermost orbital. Therefore, it is easy to form a SOMO with compound 131, which is particularly preferable.

[0078] <Estimation of SOMO levels in the interaction between metal 132 and compound 131 by quantum chemical calculations Mori> In the light-emitting element of one embodiment of the present invention, compound 131 and metal 132 form a SOMO. If the SOMO level is extremely low, the compound is not suitable for use as an electron injection layer. The SOMO levels formed when 31 interacts with metal atoms were calculated by quantum chemical calculations. The results are shown in Table 1. The organic compounds having this function include the 4',4''''-(1,4-phenylene) 2,2':6',2"-terpyridine (abbreviation: tPy2P), 4',4'' ''-(9,10-anthryl)bis(2,2':6',2"-terpyridine) (abbreviation: tPy2A), 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h ]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(2,2'-bipyridine) Diphenyl-6,6'-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 6,6 '(P-Bqn)2BPy), 2,4,6-tris(2-pyridyl)-1,3,5-tri Azine (abbreviation: 2Py3Tzn), 2,4,6-tris(5-phenylpyrimidine-2- The compound used was 1,3,5-triazine (PPm3Tzn).

[0079] [ka]

[0080] [Table 1]

[0081] The LUMO levels of the organic compounds in Table 1 were measured by cyclic voltammetry (CV). The calculation was made as follows.

[0082] The measurement device used was an electrochemical analyzer (manufactured by BAS Co., Ltd., model number: ALS model). The solution used in the CV measurements was dehydrated dimethyl ether. Dimethylformamide (DMF) (Aldrich Co., Ltd., 99.8%, Catalog No. 227 05-6) was used as the supporting electrolyte, tetra-n-butylammonium perchlorate (nB u4NClO4) (Tokyo Chemical Industry Co., Ltd., catalog number: T0836) was added at 100 mmol / The measurement target was then dissolved in water to a concentration of 2 mmol / L. The working electrode was a platinum electrode (PT E platinum electrode) as an auxiliary electrode, and a platinum electrode (B.A.S. Co., Ltd., VC-3 P t counter electrode (5 cm)) and Ag / Ag as the reference electrode. + Electrode (B.A.E. The measurements were performed at room temperature (20 The scan speed during CV measurement was standardized to 0.1 V / sec. The oxidation potential Ea [V] and reduction potential Ec [V] against the reference electrode were measured. Ea is The intermediate potential of the oxidation-reduction wave is set as Ec, and the intermediate potential of the reduction-oxidation wave is set as Ec. The potential energy of the reference electrode relative to the vacuum level is -4.94 eV. Since it is known that there is a HOMO level [eV] = -4.94-Ea, the LUMO level From the formula [eV]=-4.94-Ec, the HOMO level and the LUMO level are It can be requested.

[0083] The quantum chemical calculation program used was Gaussian09. The experiment was carried out using a high-performance computer (ICE X, manufactured by SGI). The ground state of the element, the ground state of the metal, and the ground state of a composite material of an organic compound and a metal The most stable structure was calculated using density functional theory (DFT). (d,p) and LanL2DZ were used, and the functional was B3LYP. Total energy of organic compounds and metal composites, total energy of organic compounds alone and metal alone The stabilization energy was calculated from the difference between the sum of the total energy of the body and Energy) = (Total energy of the composite material of organic compound and metal) - (Total energy of the organic compound alone) The total energy of the DFT is calculated as follows: potential energy, interelectronic electrostatic energy, electronic kinetic energy and complex interelectronic It is expressed as the sum of exchange-correlation energies including all interactions. In DFT, it is expressed as electron density. The exchange-correlation interaction is approximated by a functional (a function of a function) of the one-electron potential. Therefore, the calculations are highly accurate.

[0084] Table 1 shows the properties of manganese (Mn), a transition metal in group 7, and cobalt ( Co), the 11th group transition metals copper (Cu), silver (Ag), gold (Au), and the 13th group gold For the metals aluminum (Al) and indium (In), The calculation results of the SOMO level formed by is shown. The SOMO levels formed by lithium (Li) and each organic compound were also calculated. As a result of the calculation, in the combination of organic compounds and metals shown in Table 1, all of the organic compounds have The organic compound and the metal interact near the nitrogen in the heteroaromatic ring, stabilizing the compound. The results showed that the energy of the mixture of these organic compounds and metals was negative. In this case, the interaction between the organic compound and the metal is more energy efficient than the interaction without the organic compound. Thus, organometallic compounds that have the ability to interact with metals at tridentate or tetradentate sites are The interaction between the compound and the metal results in a stable composite material. The SOMO levels formed by organic compounds that have the ability to interact with metals at 4 dentates and each metal are as follows: The SOMO levels formed by each organic compound and Li were roughly equivalent. The composite material of the metal and an organic compound that has the function of interacting with the metal at the 4-dentate site has a high electron injection rate. In particular, the 11th group elements, Cu, Ag, Au, Composite materials using Co, a group 9 element, show high SOMO levels and are tridentate or tetradentate. Composites of metals belonging to groups 9 and 11 and organic compounds capable of interacting with metals It was found that the material has high electron injection properties.

[0085] In addition, from Table 1, the organic compounds that have the function of interacting with metals at tridentate or tetradentate sites and the metals The SOMO level formed by the above reaction is closer to the LUMO level of the organic compound than the work function of each metal. Therefore, it is suggested that the LUMO level is affected by the organic compound. By this, we have developed a complex of organic compounds and metals with high SOMO levels and excellent electron injection properties. As described above, the LUMO level of the organic compound is −3.6e It is preferable that the potential is 0.5 V or more and -2.3 eV or less.

[0086] On the other hand, when considering the manufacturing process of a light-emitting device, the EL layer of the light-emitting device, especially the electron injection layer and the cathode, are generally The electrode is often formed by vacuum deposition. It is preferable to use a material that can be subjected to vacuum deposition, i.e., a material that has a low melting point, boiling point, or sublimation point. It is preferable to use a material having a low vapor pressure during vacuum deposition. Group 13 elements have lower melting points than Group 7 and Group 9 elements, making them suitable for vacuum deposition. In particular, elements of Groups 11 and 13 such as Ag and Al have low melting points, so they are difficult to melt. By using the vacuum deposition method, metal atoms and organic compounds can be easily mixed. preferable.

[0087] Ag, Cu, Au, Al, and In can also be used as cathode materials. By using the same material for the layer 130 and the electrode 102, the light-emitting device can be easily fabricated. In addition, it is preferable to use the same material for the electron injection layer 130 and the electrode 102. This makes it possible to improve the adhesion between the electron injection layer 130 and the electrode 102, thereby improving the light-emitting element. The reliability can be improved, and the manufacturing cost of the light-emitting element can be reduced. .

[0088] In the light-emitting element of one embodiment of the present invention, a metal with a high work function is used as the electron-injection layer 130. Therefore, it can be used for a work function equal to or higher than the work function of the metal contained in the electrode 102. A metal having such a structure can be used for the electron-injection layer 130. Even if a metal with a large work function is used, there is no electron injection barrier between the electrode 102 and the electron injection layer 130. Since the walls can be reduced, the driving voltage can be reduced.

[0089] In addition, when compound 131 interacts with metal 132, metal 132 acts as an electron donor, and compound It is preferable that 131 is an electron acceptor. In this case, compound 131 has multiple electron-deficient structures. It is preferable that the compound 131 has a toe-shaped heteroaromatic ring. In this structure, the compound 131 can accept electrons. It is easy to take up, so it is easy to form SOMO when interacting with metal 132 atoms. Compounds having a molecule-deficient heteroaromatic ring have good electron transport properties, so when used in the electron injection layer, This is preferable as Compound 131 since the driving voltage of the light-emitting element can be reduced.

[0090] The electron-deficient heteroaromatic ring is preferably a nitrogen-containing heteroaromatic ring, and is preferably a pyridine ring or a diazine ring. (pyrimidine ring, pyrazine ring, pyridazine ring), or triazine ring These rings are more preferably excellent in electrochemical stability, and therefore can be used to form a highly reliable light-emitting device. In addition, since the electron transport properties are excellent, the driving voltage of the light-emitting element can be reduced. The compound having an electron-deficient heteroaromatic ring can be It may be a metal complex.

[0091] In addition, when an organic compound is used as the compound 131, the number of carbon atoms is 25 or more and 100 or less. By setting the carbon number in this range, it is possible to obtain an organic compound with excellent sublimation properties. This makes it possible to suppress the thermal decomposition of organic compounds during vacuum deposition, resulting in good material usage. Furthermore, it is preferable that the glass transition point (Tg) is 100° C. or higher. By using an organic compound having such a Tg in the EL layer, a light-emitting element having excellent heat resistance can be obtained. It can be said that:

[0092] In addition, the organic compound used in this calculation has a N atom on a heterocycle and multiple The heterocycle has conjugated double bonds arranged in the order of NCCN. When the compound 131 has a binding site, a chelate ring is formed when the compound 131 interacts with the metal 132. (Compound 131 and metal 132 interact to form a ring structure). The combination of compound 131, which can form a chelate ring, and metal 132 is easy to interact with each other. This is preferred because it is easy to form a SOMO.

[0093] Therefore, a tridentate or tetradentate compound that can be suitably used in a light-emitting element according to one embodiment of the present invention The organic compound having the function of interacting with metals has a structure represented by the following general formula (G0): do.

[0094] [ka]

[0095] In general formula (G0), A 1 , A 2 and A 3 are each independently substituted or unsubstituted A represents a heteroaromatic ring having 1 to 30 carbon atoms. 1 , A 2 and A 3 form a condensed ring with each other It's fine if it is.

[0096] The organic compound represented by the general formula (G0) is a compound in which the N on the heteroaromatic ring is arranged in the order of NCCN. It has a conjugated double bond and has the function of interacting with metals at a tridentate or higher level. Thus, organic compounds with this structure form SOMOs when mixed with metals. Since the light-emitting element can be easily formed, it can be suitably used for the light-emitting element of one embodiment of the present invention.

[0097] In addition, in the above general formula (G0), A 1 , A 2 and A 3 The number of substituted or unsubstituted carbon atoms represented by Examples of the heteroaromatic ring having 1 to 30 rings include a pyridine ring, a diazine ring (a pyrimidine ring, Pyrazine ring, pyridazine ring), triazine ring, quinoline ring, quinoxaline ring, quinazoline ring, benzoquinazoline ring, phenanthroline ring, azafluoranthene ring, imidazole ring , oxazole ring, oxadiazole ring, etc. Specifically, the following (A-1) Examples of the heteroaromatic rings are shown in (A-16). 1 , A 2 and A 3 Represented by The substituted or unsubstituted heteroaromatic ring having 1 to 30 carbon atoms is not limited to these. 1 , A 2 and A 3 may form a condensed ring. For example, A 1 and A 2 are bonded to each other, A phenanthroline ring may be formed.

[0098] [ka]

[0099] In addition, a tridentate or tetradentate gold atom that can be suitably used in a light-emitting element according to one embodiment of the present invention can be used. The organic compound having the function of interacting with the group has a structure represented by the following general formula (G1): .

[0100] [ka]

[0101] In general formula (G1), X 1 ~X 6 are each independently carbon (C) or nitrogen (N ), wherein carbon is hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted alkyl group having 3 cycloalkyl groups of 6 to 7, substituted or unsubstituted aromatic hydrocarbons having 6 to 25 carbon atoms a substituted or unsubstituted heteroaromatic hydrocarbon group having 3 to 30 carbon atoms, R 1 ~R 4 each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted substituted or unsubstituted cycloalkyl groups having 3 to 7 carbon atoms; Aromatic hydrocarbon groups or substituted or unsubstituted heteroaromatic hydrocarbons having 3 to 30 carbon atoms Ar represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted alkyl group having 3 a cycloalkyl group having 6 to 7 carbon atoms, an aromatic hydrocarbon group having 6 to 60 carbon atoms, or a represents a heteroaromatic hydrocarbon group having an amino acid sequence of 1 to 60;

[0102] The organic compound represented by the general formula (G1) has a tridentate or tetradentate function that interacts with metals. The organic compounds having the function of pyridine ring, diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring, It is more preferable that the compound has at least one of a phenyl ring, a triazine ring, or a triazine ring. Since the electrochemical stability is excellent, a light-emitting element with good reliability can be provided. Since the light emitting element has excellent transmission properties, a light emitting element with reduced driving voltage can be provided.

[0103] In addition, a tridentate or tetradentate gold atom that can be suitably used in a light-emitting element according to one embodiment of the present invention can be used. The organic compound having the function of interacting with the genus has a structure represented by the following general formula (G2): .

[0104] [ka]

[0105] In general formula (G2), X 1 and X 2 are each independently carbon (C) or nitrogen (N ), wherein carbon is hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted alkyl group having 3 cycloalkyl groups of 6 to 7, substituted or unsubstituted aromatic hydrocarbons having 6 to 25 carbon atoms a substituted or unsubstituted heteroaromatic hydrocarbon group having 3 to 30 carbon atoms, R 1 ~R 8 each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted substituted or unsubstituted cycloalkyl groups having 3 to 7 carbon atoms; Aromatic hydrocarbon groups or substituted or unsubstituted heteroaromatic hydrocarbons having 3 to 30 carbon atoms Ar represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted alkyl group having 3 a cycloalkyl group having 6 to 7 carbon atoms, an aromatic hydrocarbon group having 6 to 60 carbon atoms, or a represents a heteroaromatic hydrocarbon group having an amino acid sequence of 1 to 60;

[0106] Organic compounds with a pyridine skeleton tend to have a high LUMO level. When an organic compound having a pyridine skeleton as represented by general formula (G2) is mixed with a metal, It is possible to create composite materials with high SOMO levels. By mixing metals with organic compounds that have the ability to interact with metals at the tetradentate or tetradentate positions, high electric potential can be obtained. Composite materials with molecular injectivity can be fabricated.

[0107] In addition, a tridentate or tetradentate gold atom that can be suitably used in a light-emitting element according to one embodiment of the present invention can be used. The organic compound having the function of interacting with the group is represented by the following general formula (G3-1) to (G3-3). It is represented by one of the following.

[0108] [ka]

[0109] In general formulae (G3-1) to (G3-3), R 1 ~R 8 are each independently hydrogen an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 25 carbon atoms, or a substituted or Represents an unsubstituted heteroaromatic hydrocarbon group having 3 to 30 carbon atoms, and Ar is hydrogen, an alkyl group having 3 to 4 carbon atoms; a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms; Aromatic hydrocarbon groups with 2 to 60 carbon atoms, or heteroaromatic hydrocarbon groups with 2 to 60 carbon atoms Represents.

[0110] In addition, a tridentate or tetradentate gold atom that can be suitably used in a light-emitting element according to one embodiment of the present invention can be used. The organic compound having the function of interacting with the group is represented by the following general formulas (G4-1) to (G4-3). It is represented by one of the following.

[0111] [ka]

[0112] In the general formulae (G4-1) to (G4-3), Ar is hydrogen, Alkyl groups, substituted or unsubstituted cycloalkyl groups having 3 to 7 carbon atoms, and groups having 2 to 6 carbon atoms. Aromatic hydrocarbon groups with 0 or less carbon atoms, or heteroaromatic hydrocarbon groups with 2 to 60 carbon atoms. .

[0113] <Examples of Substituents> In general formulae (G0) to (G3), R 1 ~R 8 or C has The substituents include hydrogen, an alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted alkyl group having 3 or more carbon atoms, and the like. Cycloalkyl groups with up to 7 carbon atoms, substituted or unsubstituted aromatic hydrocarbons with 6 to 25 carbon atoms or a substituted or unsubstituted heteroaromatic hydrocarbon group having 3 to 30 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, Examples of the alkyl group include a butyl group, an isobutyl group, a tert-butyl group, and an n-hexyl group. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclopentyl group. Examples of the aryl group include a phenyl group, a cyclohexyl group, and the like. Specific examples include a naphthyl group, a biphenyl group, a fluorenyl group, and a spirofluorenyl group. More specifically, examples thereof include the following structural formulas (R-1) to (R-56): In addition, R 1 ~R 8 or a substituent represented by The groups are not limited to these.

[0114] [ka]

[0115] In the general formulae (G0) to (G3), Ar is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. , a substituted or unsubstituted cycloalkyl group having 3 to 7 carbon atoms, an aromatic group having 6 to 60 carbon atoms The alkyl group represents an aromatic hydrocarbon group or a heteroaromatic hydrocarbon group having 3 to 60 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isopropyl ... Examples of the cycloalkyl group include an isobutyl group, a tert-butyl group, and an n-hexyl group. Examples of the alkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cycloalkyl group. The aryl group may be a phenyl group, a naphthyl group, or the like. Specific examples include a biphenyl group, a fluorenyl group, and a spirofluorenyl group. More specifically, for example, the following structural formulas (Ar-1) to (Ar-48) can be used. The groups represented by Ar are not limited to these, and may have a substituent. is also good.

[0116] [ka]

[0117] <Specific examples of compounds> Specific structures of the compounds represented by the general formulae (G0) to (G3) include the following structural formulae: Organic compounds represented by the structural formulas (100) to (111) and (200) to (211) The organic compounds represented by the general formulas (G0) to (G3) are , but is not limited to the examples below.

[0118] [ka]

[0119] [ka]

[0120] In addition, the molar ratio of the metal 132 to the compound 131 is preferably 0.1 or more and 10 or less. It is preferable that the ratio is 0.2 or more and 2 or less, and it is even more preferable that the ratio is 0.2 or more and 0.8 or less. It is preferable to mix the metal 132 and the compound 131 in such a ratio to obtain good electron injection. It is possible to provide a light-emitting device having a high reflectivity. If the molar ratio of metal 132 is too small, the metal 132 will interact with the metal 132 to form SOMO. Since the amount of compound 131 is small, the electron injection property may be reduced. When the molar ratio of the metal 132 is higher than the above ratio, the electron injection layer 130 Since the transmittance of the light emitting element decreases, the light emitting efficiency of the light emitting element may decrease.

[0121] In addition, the LUMO level of the organic compound contained in the electron transport layer 118 is It is preferable that the SOMO level is lower than the SOMO level formed by the electron injection layer 1. Since the electron injection barrier between the semiconductor layer 30 and the electron transport layer 118 is reduced, the driving voltage can be reduced. In addition, since the organic compound contained in the electron transport layer 118 is required to have electron transport properties, Therefore, it is preferable that the compound has an electron-deficient heteroaromatic ring.

[0122] The thickness of the electron injection layer 130 is preferably 3 nm or more, and more preferably 5 nm or more. By adopting this structure, the metal 132 and the compound 131 are mixed together to form a composite material, which is excellent. The thickness of the electron injection layer 130 is preferably 50 nm or less. It is preferable that the thickness is 20 nm or less, more preferable that the thickness is 10 nm or less. As a result, the influence of light absorption by the electron injection layer 130 is reduced, and a light emitting device exhibiting high luminous efficiency is obtained. can be provided.

[0123] <Light-emitting element configuration example 2> Next, a configuration example different from that of the light emitting element 150 shown in FIG. 1 will be described below with reference to FIG. 2(A). Make a statement.

[0124] FIG. 2A is a schematic cross-sectional view illustrating a light-emitting device of one embodiment of the present invention. In this figure, the same hatch pattern is used for parts having the same functions as those in FIG. In addition, parts having similar functions are given similar reference symbols, A detailed description thereof may be omitted.

[0125] The light emitting element 152 has a pair of electrodes (electrode 101 and electrode 102). The EL layer 100 includes at least a light-emitting layer 140 and an electron-emitting layer 142. The semiconductor device further includes a buffer layer 127. The buffer layer 127 is an electron injecting layer. It is provided between the layer 130 and the electrode 102 .

[0126] The EL layer 100 shown in FIG. 2A includes a hole injection layer 111, a positive hole injection layer 112, a positive hole injection layer 113, a positive hole injection layer 114, a positive hole injection layer 115, a positive hole injection layer 116, a positive hole injection layer 117, a positive hole injection layer 118, a positive hole injection layer 119 ... It has functional layers such as a hole transport layer 112 and an electron transport layer 118 .

[0127] In one embodiment of the present invention, the electron injection layer 130 is made of a composite material of the above-mentioned compound 131 and metal 132. The buffer layer 127 is made of a compound 133 having an electron-deficient heteroaromatic ring. The leg-shaped heteroaromatic ring has excellent electron transport properties and can reduce the driving voltage of the light-emitting device.

[0128] By sandwiching the buffer layer 127 between the electron injection layer 130 and the electrode 102, the electrode 102 This is preferable because it can reduce the electron injection barrier between the backside and the electron injection layer 130. The thickness of the photoresist layer 127 is preferably 1 nm or more and 20 nm or less. The electron injection barrier can be reduced while maintaining the electron transport property.

[0129] In addition, the LUMO level of the compound 133 is higher than the SOMO level formed in the electron injection layer 130. By adopting such a configuration, the electron injection layer 130 and the electrode 102 This is preferable because it is possible to reduce the electron injection barrier between the

[0130] <Configuration example 3 of light-emitting element> In addition, the light emitting element 150 shown in FIG. 1(A) and the light emitting element 152 shown in FIG. An example of the configuration will be described below with reference to FIG.

[0131] FIG. 2B is a schematic cross-sectional view illustrating a light-emitting element of one embodiment of the present invention. In this figure, the same hatch pattern is used for parts having the same functions as those in FIG. In addition, parts having similar functions are given similar reference symbols, A detailed description thereof may be omitted.

[0132] The light emitting element 154 has a pair of electrodes (electrode 101 and electrode 102). The EL layer 100 includes at least a light-emitting layer 140 and an electron-emitting layer 142. The charge generating layer 129 has an electron injection layer 130. It is provided between the layer 130 and the electrode 102 .

[0133] The EL layer 100 shown in FIG. 2B includes a hole injection layer 111, a hole injection layer 112, a light emitting layer 140, and a cathode. It has functional layers such as a hole transport layer 112 and an electron transport layer 118 .

[0134] The charge generating layer 129 is provided between the electrode 102 and the electron injection layer 130 as shown in FIG. 2(B). This reduces the probability that the electron injection layer 130 will come into contact with oxygen and moisture, further reducing the emission of It is expected that the moisture resistance and oxidation resistance of optical elements will be improved.

[0135] The charge generating layer 129 may have a structure in which an electron accepting material is added to a hole transporting material. The electron transport material may be added with an electron donor material. The structure may be a laminated structure, but it is a structure in which an electron accepting material is added to a hole transporting material. This is preferable because it improves moisture resistance and reduces the number of layers.

[0136] As described above, when the charge generating layer 129 has a structure including a hole transporting material and an electron accepting material, In this case, the electron injection layer 130 is made of a metal material having a small work function, such as an alkali metal or an alkaline earth metal. When the material is used, the electron-accepting material of the charge generating layer 129 can be obtained by dissolving the material used in the electron injection layer 130. Since electrons are extracted, depletion occurs near the interface between the charge generation layer 129 and the electron injection layer 130. This can cause the drive voltage to increase. In the present embodiment, a layer having a function of transferring electrons is provided between the electron injection layer 130 and the charge generation layer 129. It was necessary to do so.

[0137] On the other hand, in the light-emitting element of one embodiment of the present invention, the electron-injection layer 130 contains a transition metal and a tridentate or tetradentate By using a composite material with an organic compound having a function of interacting with a metal, Since the charge generating layer 129 can be provided without generating a depletion layer, the number of layers can be reduced. Therefore, a light-emitting device with a low driving voltage can be fabricated.

[0138] The thickness of the charge generating layer 129 is not particularly limited and can be adjusted appropriately. For example, By adjusting the film thickness from the light-emitting layer 140 to the electrode 102, That is, the light emitted from the charge generating layer 129 can be efficiently extracted to the outside of the light emitting element. By adjusting the film thickness, the light extraction efficiency can be improved.

[0139] In addition, it is preferable that the charge generating layer 129 and the electrode 102 are provided in contact with each other. This reduces the electron injection barrier between the electrode 102 and the EL layer 100, thereby The driving voltage can be reduced. Furthermore, the charge generating layer 129 and the electron injection layer 130 are in contact with each other. In one embodiment of the present invention, the charge generating layer 129 and the electron injection layer 130 are in contact with each other. Since a light-emitting element with a low driving voltage can be fabricated even when the EL The number of layers 100 stacked can be reduced.

[0140] In addition, as the electron-accepting material of the charge generating layer 129, a transition metal oxide is preferably used. Examples of the transition metal oxide include titanium oxide and vanadium oxide. , tantalum oxide, molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium Examples of the oxides include aluminum oxide, chromium oxide, zirconium oxide, hafnium oxide, and silver oxide. In particular, molybdenum oxide is preferred because it is stable in the air, has low hygroscopicity, and is inexpensive. By using the transition metal oxide, the electrons between the electrode 102 and the charge generating layer 129 can be This is preferable because the injection barrier can be reduced. The light-emitting element has a transition metal element, and the charge generating layer 129 has a transition metal element. The electron accepting material contained in the charge generating layer 129 is not limited to the above-mentioned compounds.

[0141] The charge generating layer 129 may have a hole transporting material having a pyrrole skeleton, a thiophene skeleton, or the like. It is preferable to use an organic compound containing either a furan skeleton or an aromatic amine skeleton. Since the organic compound having such a skeleton has a high hole transporting property, it is preferable to use the organic compound for the charge generating layer 129. This allows the driving voltage of the light-emitting element to be reduced. The transport material is not limited to the above-mentioned compounds.

[0142] In addition, the above-mentioned compound 132 has a function of interacting with a metal at a tridentate or tetradentate position. The composite material of 31 can be used in thin-film solar cells. More specifically, The layer can also be suitably used as an electron injection layer.

[0143] <Components of light-emitting element> Next, the components of the light-emitting device shown in FIGS. 1 and 2 will be described in detail below.

[0144] ≪Electron injection layer≫ The electron injection layer 130 is a layer containing a substance with high electron injection properties, and is a layer containing a tridentate or trivalent metal with the above-mentioned metal. A composite material of an organic compound having a function of interacting with a metal at a tetradentate can be preferably used. The organic compound having a function of interacting with a metal at a tridentate or tetradentate position is represented by the general formula ( Organic compounds represented by the structural formula (G0) to (G4-3) can be used. Using organic compounds represented by the structural formulas (100) to (111) and (200) to (211) In particular, diazine (pyrimidine or pyrazine) and triazine skeletons can be used. Heterocyclic compounds having such a structure are preferred because they have high electron transport properties and contribute to reducing the driving voltage. In addition, organic compounds that have the ability to interact with metals at tridentate or tetradentate sites are 1×10 - 6 cm 2 It is preferable that the material has an electron mobility of 1 / Vs or more. Materials other than those mentioned above may be used in the electron injection layer 130 as long as they have high conductivity.

[0145] <Hole injection layer> The hole injection layer 111 and the charge generation layer 129 are connected to one of a pair of electrodes (the electrode 101 or the electrode 102) to promote hole injection by reducing the hole injection barrier. For example, the material may be a transition metal oxide, a phthalocyanine derivative, or an aromatic amine. Examples of transition metal oxides include molybdenum oxide, vanadium oxide, and ruthenium oxide. , tungsten oxide, manganese oxide, etc. Phthalocyanine derivatives include Examples of the aromatic amine include phthalocyanine and metal phthalocyanine. Examples include phenylenediamine derivatives and polythiophenes. Polymers such as phosphorus can also be used, for example self-doped polythiophene. Poly(ethylenedioxythiophene) / poly(styrenesulfonic acid) are representative examples. Here is an example.

[0146] The hole injection layer 111 and the charge generation layer 129 are made of a hole transporting material and an electron transporting material. Alternatively, a layer having a composite of electron-accepting materials may be used. A laminate of a layer containing the above-mentioned material and a layer containing a hole transporting material may be used. It is possible to give and receive charges in a steady state or in the presence of an electric field. Materials that exhibit electron-accepting properties Examples include quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives. Examples of organic acceptors include 7,7,8,8-tetrachloroethylene. No-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), Chlorani 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexa- HAT-CN, 1,3,4,5,7,8-Hexafluorotetraphenylene Electron-withdrawing groups such as tetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ) (especially full In particular, compounds containing halogen groups such as fluorine and cyano groups are included. Compounds such as AT-CN in which an electron-withdrawing group is bonded to a condensed aromatic ring containing multiple heteroatoms. is preferred because it is thermally stable. Also, electron-withdrawing groups (especially halogen groups such as fluoro groups) [3] Radialene derivatives having a cyclic group (such as a cyano group) are preferred because of their extremely high electron-accepting properties. Specifically, α,α',α''-1,2,3-cyclopropanetriylidenetris[4- Cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α'' -1,2,3-cyclopropanetriylidenetris[2,6-dichloro-3,5-difluoro α,α',α''-1, 2,3-Cyclopropanetriylidenetris[2,3,4,5,6-pentafluorobenzene In addition, transition metal oxides, such as those of Groups 4 to 8, The oxides of group metals can be used. Specifically, vanadium oxide, niobium oxide, Tantalum, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, rhenium oxide Among them, molybdenum oxide is stable in the air, has low hygroscopicity, and is easy to handle. This is preferable because it is

[0147] As the hole transporting material, a material having a higher hole transporting property than an electron transporting property can be used. ×10 -6 cm 2It is preferable that the material has a hole mobility of 1 / Vs or more. The aromatic amines and carbenes mentioned as examples of hole transport materials that can be used in the light-emitting layer 140 are Bazole derivatives, aromatic hydrocarbons, stilbene derivatives, etc. can be used. It is particularly preferred that the heteroaromatic skeleton has 1 to 20 carbon atoms, particularly nitrogen-containing heteropentacyclic aromatic rings. The hole transporting material may be a polymer compound.

[0148] Other examples of hole transport materials include aromatic hydrocarbons, such as 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), 9,1 0-Di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene 2-tert-butylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAn th), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA) , 2-tert-butyl-9,10-bis[2-(1-naphthyl)phenyl]anthracene 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7- Tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl 9,10-di(2-naphthyl)anthracene, 9,9'-bianthryl, 10,1 0'-Diphenyl-9,9'-bianthryl, 10,10'-bis(2-phenylphenyl) 10,10'-bis[(2,3,4,5,6-pentafluorophenyl) phenyl)phenyl]-9,9'-bianthryl, anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, etc. In addition, pentacene, coronene, etc. can also be used. -6 cm 2 / Vs or more, and an aromatic hydrocarbon having 14 to 42 carbon atoms. It is more preferable to use

[0149] The aromatic hydrocarbon may have a vinyl skeleton. Examples of aromatic hydrocarbons include 4,4'-bis(2,2-diphenylvinyl)biphenyl. (abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl] anthracene (abbreviation: DPVPA), etc.

[0150] Also, 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]fluor phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), 4,4',4''-(phenyl) (1,3,5-phenyl-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), 1,3,5-Tri(dibenzothiophen-4-yl)benzene (abbreviation: DBT3P-II ), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)fluor 4-[4-(9-phenyl)dibenzothiophene (abbreviation: DBTFLP-III), [6-phenyl-9H-fluoren-9-yl]phenyldibenzothiophene (abbreviation :DBTFLP-IV), 4-[3-(triphenylen-2-yl)phenyl]dibenzo Thiophene compounds such as thiophene (abbreviation: mDBTPTp-II), furan compounds, An orene compound, a triphenylene compound, a phenanthrene compound, etc. can be used. Among the above-mentioned compounds, pyrrole skeleton, furan skeleton, thiophene skeleton, aromatic amine skeleton, Compounds having this structure are stable and reliable, and are therefore preferred. The material has a high hole transporting property and contributes to reducing the driving voltage.

[0151] <Hole transport layer> The hole transport layer 112 is a layer containing a hole transporting material. The hole transport layer 112 is formed by injecting the electrons from the hole injection layer 111. The organic layer 140 has a function of transporting the holes to the light-emitting layer 140 .

[0152] At this time, the LUMO level of the acceptor material of the hole injection layer 111 and the LUMO level of the light emitting layer 14 A hole transporting material having a HOMO level between the HOMO level of the material having 0 and the HOMO level of the material having 1 is called a hole transporting material. It is preferable to use it for the transport layer 112. In addition, the hole transport layer 112 may be a single layer or a bilayer. In this case, the HOMO quasi-layer may be formed from the hole injection layer 111 to the light emitting layer 140. It is preferable to laminate the hole transport layer materials in order of decreasing potential. When stacking two or more layers, the HOMO quasi-state of each hole transport material must be adjusted to ensure smooth hole transport. The difference in potential is preferably 0 eV or more and 0.5 eV or less, and more preferably 0 eV or more and 0. It is 3 eV or less, and more preferably 0 eV or more and 0.2 eV or less.

[0153] Examples of materials having hole transport properties include 4,4'-bis[N-(1-naphthyl)- N-phenylamino]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- phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenyl Fluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3 '-(9-Phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP) ), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenyl PCBA1BP, 4,4'-diphenyl-4''-(9-phenyl- 9H-Carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4- (1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenyl PCBANB, 4,4'-di(1-naphthyl)-4''-(9-phenyl) PCBNBB, 9H-carbazol-3-yl)triphenylamine ,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-carbazol-3-yl)phenyl]spiro-9,9'-bi Compounds with an aromatic amine skeleton, such as fluorene-2-amine (PCBASF) 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N- Carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl) 3,3'-bis(9-phenyl- 9H-carbazole (abbreviation: PCCP) and other compounds with a carbazole skeleton, ,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene)(abbreviation Name: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-ful oren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4 -[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzyl Compounds with a thiophene skeleton, such as dibenzothiophene (abbreviation: DBTFLP-IV), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation :DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl )phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II) Among the above, compounds having an aromatic amine skeleton are preferred. Compounds having a carbazole skeleton have good reliability and high hole transport properties. This is also preferable because it contributes to reducing the driving voltage. A hole transporting material may be selected from such substances.

[0154] Furthermore, as a material with high hole transport properties, for example, 3-[4-(1-naphthyl)-phenyl PCPN, 3-[4-(9-phenanyl)-9-phenyl-9H-carbazole PCPPn), 4 -Phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine PCBA1BP, 4,4'-di(1-naphthyl)-4''-(9-phenyl -9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 4- Phenyldiphenyl-(9-phenyl-9H-carbazol-3-yl)amine (abbreviation: P CA1BP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP ), N-[4-(9H-carbazol-9-yl)phenyl]-N-(4-phenyl)phenyl Phenylaniline (abbreviation: YGA1BP), 1,3,5-tri(dibenzothiophene-4- yl)-benzene (abbreviation: DBT3P-II), 4,4',4''-(benzene-1,3 ,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), 4-phenyl- 4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) ), 4-[3-(triphenylene-2-yl)phenyl]dibenzothiophene (abbreviation: m DBTPTp-II), 4,4'-bis[N-(1-naphthyl)-N-phenylamino] Biphenyl (abbreviation: NPB or α-NPD) and N,N'-bis(3-methylphenyl) -N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TP D), 4,4',4''-tris(carbazol-9-yl)triphenylamine (abbreviation TCTA), 4,4',4''-tris(N,N-diphenylamino)triphenyla MIN (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)- N-phenylamino]triphenylamine (abbreviation: MTDATA), 4,4'-bis[N -(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl( Compounds with aromatic amine skeletons such as 3-[N-(9-phenylcarbamoyl)phenyl]- carbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: P CzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenyl] phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1 -naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazol Other examples include 4,4'-di(N-carbazole) and 4,4'-di(N-carbazole). 1,3,5-Tris[4-(N-carbazolyl)biphenyl (abbreviation: CBP), Carbazole compounds such as phenyl]benzene (TCPB), amine compounds, diphenyl Thiophene compounds, dibenzofuran compounds, fluorene compounds, triphenylene compounds The substances listed here are mainly 1×10 -6 cm 2 / Vs or higher. However, the transport of holes is higher than that of electrons. Other substances may be used as long as they have high resistance.

[0155] In addition, the compounds usable for the hole transport layer can be used as the hole injection layer. It can also be suitably used as a hole transport material in the charge generating layer 129. can.

[0156] <Light-emitting layer> The light-emitting layer 140 may be a light-emitting layer of purple, blue, cyan, green, yellow-green, yellow, orange, or red. The light-emitting layer 140 includes a light-emitting material having a function of exhibiting at least one light emission. In addition to the material, one or both of an electron transporting material and a hole transporting material may be used as a host material. Includes.

[0157] In addition, as light-emitting materials, there are light-emitting substances that can convert singlet excitation energy into light emission and triplet excitation substances that can convert singlet excitation energy into light emission. A luminescent material capable of converting excitation energy into luminescence can be used. The active substances include the following:

[0158] Luminescent substances that can convert singlet excitation energy into light emission include fluorescent substances (fluorescent The fluorescent compound is not particularly limited, but may be an anthracene derivative. Conductors, tetracene derivatives, chrysene derivatives, phenanthrene derivatives, pyrene derivatives, peri ene derivatives, stilbene derivatives, acridone derivatives, coumarin derivatives, phenoxazine derivatives Conductors, phenothiazine derivatives, etc. are preferred, and for example, the following substances can be used.

[0159] Specifically, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2 ,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl -9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2 BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoro 1,6-Pyrene-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn) , N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H -fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMem FLPAPrn), N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl )phenyl]-N,N'-bis(4-tert-butylphenyl)-pyrene-1,6-di Amine (abbreviation: 1,6tBu-FLPAPrn), N,N'-diphenyl-N,N'-biphenyl 4-(9-phenyl-9H-fluoren-9-yl)phenyl]-3,8-dicyclo[4-(9-phenyl-9H-fluoren-9-yl)phenyl] Hexylpyrene-1,6-diamine (abbreviation: ch-1,6FLPAPrn), N,N'- (Pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2- d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), N,N'-bis[ 4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene 4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4 '-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4 -(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl) )triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(1 0-Phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), Perylene, 2,5,8,11-Tetra(tert-butyl)perylene (abbreviation Name: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H -Carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), 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 N-[4-(9,1 0-Diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4 -Phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'' ,N''',N'''-Octaphenyldibenzo[g,p]chrysene-2,7,10,1 5-Tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl-2 -anthryl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PC APA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl ]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 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-bis(1,1'-biphenyl -N-[4-(9H-carbazol-9-yl)phenyl]-N-phenyl 2-Anthracenamine (abbreviation: 2YGABPhA), N,N,9-triphenylamine Diphenyl ether-9-amine (abbreviation: DPhAPhA), Coumarin 6, Coumarin 545T, N ,N'-Diphenylquinacridone (abbreviation: DPQd), Rubrene, 2,8-di-tert -Butyl-5,11-bis(4-tert-butylphenyl)-6,12-diphenyl Thracene (abbreviation: TBRb), Nile Red, 5,12-bis(1,1'-biphenyl- 4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4 -(Dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-ylidene ) propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6 ,7-Tetrahydro-1H,5H-benzo[ij]quinolizin-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) phenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: pm PhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl- 2,3,6,7-Tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl) Thenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2 -{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6, 7-Tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4 H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6- Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene 2-{2,6-bis[2-(8-methylphenyl)propanedinitrile (abbreviation: BisDCM), 1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzyl 4H-pyran-4-ylidene)propane BisDCJTM, 5,10,15,20-tetraphenylbis Benzo[5,6]indeno[1,2,3-cd:1',2',3'-lm]perylene, etc. Some examples include:

[0160] In addition, examples of luminescent substances that can convert triplet excitation energy into luminescence include phosphorescent substances. Phosphorescent compounds include iridium, rhodium, Porphyrins, platinum-based organometallic complexes, and metal complexes are also examples. Examples of such complexes include platinum complexes and organic iridium complexes having ligands, and among these, organic iridium complexes and For example, iridium orthometal complexes are preferred. H-triazole ligand, 1H-triazole ligand, imidazole ligand, pyridine ligand Ligands include pyrimidine ligands, pyrazine ligands, and isoquinoline ligands. In this case, the phosphorescent compound is a triplet MLCT (Metal to Ligand Ch) It has an absorption band of the Argon Transfer transition.

[0161] Examples of substances having a blue or green emission peak include tris{2-[5-(2 -methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazo 3-yl-κN 2 ]phenyl-κC}iridium(III) (abbreviation: Ir(mpp tz-dmp)3), tris(5-methyl-3,4-diphenyl-4H-1,2,4-tris( riazolate)iridium(III) (abbreviation: Ir(Mptz)3), tris[4-(3- Biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]i Iridium(III) (abbreviation: Ir(iPrptz-3b)3), tris[3-(5-biphenyl] (phenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]irid Ir(III) (abbreviation: Ir(iPr5btz)3), a 4H-triazole skeleton and organometallic iridium complexes having tris[3-methyl-1-(2-methylphenyl) -5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: Ir (Mptz1-mp)3), tris(1-methyl-5-phenyl-3-propyl-1H- 1,2,4-Triazolate)iridium(III) (abbreviation: Ir(Prptz1-Me) 3) and fac-triazole-based organometallic iridium complexes. S[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole] Iridium(III) (abbreviation: Ir(iPrpmi)3), tris[3-(2,6-dimethyl phenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(I II) Imidazole skeleton-containing compounds such as Ir(dmpimpt-Me)3 Organic metal iridium complexes and bis[2-(4',6'-difluorophenyl)pyridinato N,C 2’ ]Iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FI r6), Bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]Ili Dium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis (Trifluoromethyl)phenyl]pyridinato-N,C 2’}Iridium(III) pico Ir(CF3ppy)2(pic) (fluorophenyl)pyridinato-N,C 2’ ]Iridium(III) acetylacetonate (abbreviation: FIr(acac)) Among the above, 4H-triazole is an organometallic iridium complex. Nitrogen-containing five-membered heterocyclic skeletons such as 1H-triazole skeleton and imidazole skeleton The organometallic iridium complex has high triplet excitation energy and is highly reliable and has excellent luminescence efficiency. It is particularly preferred because it is also excellent in

[0162] In addition, examples of substances having a green or yellow emission peak include tris(4-methylphenyl) Ir(mppm)3, Tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: I r(tBuppm)3), (acetylacetonato)bis(6-methyl-4-phenylpyridine Iridium(III) (abbreviation: Ir(mppm)2(acac)), (acetylacetonate ruacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium( III) (abbreviation: Ir(tBuppm)2(acac)), (acetylacetonato)bis [4-(2-norbornyl)-6-phenylpyrimidinato]iridium(III) (abbreviation Ir(nbppm)2(acac)), (acetylacetonato)bis[5-methyl-6 -(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: Ir(mpmppm)2(acac)), (acetylacetonato)bis{4,6-dimethyl 2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl- {κC}iridium(III) (abbreviation: Ir(dmppm-dmp)2(acac)), ( Acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III)( Abbreviation: Ir(dppm)2(acac) (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazine) Iridium(III) (abbreviation: Ir(mppr-Me)2(acac)), (acetylacetonate ruacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinate)irid Pyrazine skeleton such as Ir(III) (abbreviation: Ir(mppr-iPr)2(acac)) Organometallic iridium complexes and tris(2-phenylpyridinato-N,C 2’ ) Iridium(III) (abbreviation: Ir(ppy)3), bis(2-phenylpyridinato-N ,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(ppy)2(ac ac)), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: Ir(bzq)2(acac)), tris(benzo[h]quinolinato)iridium Ir(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) acetylacetonate (abbreviation: Ir(pq)2(ac Organometallic iridium complexes with pyridine skeletons such as bis(2,4-difluorophenyl) and Venyl-1,3-oxazolato-N,C 2’ ) Iridium(III) acetylacetoner Ir(dpo)2(acac)), bis{2-[4'-(perfluorophenyl (phenyl)pyridinato-N,C 2’}Iridium(III) acetylacetonate ( Abbreviation: Ir(p-PF-ph)2(acac)), bis(2-phenylbenzothiazol -N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(bt)2(a In addition to organometallic iridium complexes such as tris(acetylacetonato)(monophenyl) Anthroline) terbium(III) (abbreviation: Tb(acac)3(Phen)) Among the above, the organometallic iridium complexes having a pyrimidine skeleton are Dium complexes are particularly preferred because they are remarkably excellent in reliability and luminous efficiency.

[0163] Examples of substances having a yellow or red emission peak include diisobutyryl Methanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(II I) (abbreviation: Ir(5mdppm)2(dibm)), bis[4,6-bis(3-methyl Phenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: Ir (5mdppm)2(dpm)), bis[4,6-di(naphthalene-1-yl)pyrimidinyl] Nato](dipivaloylmethanato)iridium(III) (abbreviation: Ir(d1npm)2( Organometallic iridium complexes with pyrimidine skeletons such as (acetylacetamide) Iridium(III) r(tppr)2(acac)), bis(2,3,5-triphenylpyrazine)(dipyridine) Valoylmethanato)iridium(III) (abbreviation: Ir(tppr)2(dpm)), ( Acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]i Ir(Fdpq)2(acac) and other pyrazine-based compounds Organometallic iridium complexes 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( In addition to organometallic iridium complexes with pyridine skeletons such as acac), 2,3,7, 8,12,13,17,18-Octaethyl-21H,23H-porphyrin platinum(II) ) (abbreviation: PtOEP) and tris(1,3-diphenyl-1,3-propanediol). (Eu(DB))(monophenanthroline)europium(III) M) 3(Phen)), tris[1-(2-thenoyl)-3,3,3-trifluoroacetate [Tonato](monophenanthroline)europium(III) (abbreviation: Eu(TTA)3( Among the above, rare earth metal complexes such as pyrimidine skeletons are Organometallic iridium complexes having the above structure are particularly preferred because they are extremely reliable and have excellent luminous efficiency. In addition, organometallic iridium complexes with pyrazine skeletons can emit red light with good chromaticity. can be done.

[0164] In addition to phosphorescent compounds, other materials that can convert triplet excitation energy into light include: Thermally activated delayed fluorescence Therefore, they are called phosphorescent compounds. The part may be read as a thermally activated delayed fluorescent compound. The difference between the singlet and triplet excited energy levels of the photoactive compound is small. It has the function of converting triplet excitation energy to singlet excitation energy by reverse intersystem crossing. Therefore, a small amount of thermal energy can convert the triplet excited state to a singlet excited state. It is possible to upconvert (reverse intersystem crossing) the singlet excited state, and efficiently emit light (fluorescence) from the singlet excited state. The conditions for efficient thermally activated delayed fluorescence are The difference between the excited energy level and the triplet excited energy level is preferably greater than 0 eV. 0.3 eV or less, more preferably greater than 0 eV and less than 0.2 eV, and even more preferably 0 eV or more and 0.1 eV or less.

[0165] When the thermally activated delayed fluorescent compound is composed of one kind of material, for example, the following material is used: It can be used.

[0166] First, fullerene and its derivatives, acridine derivatives such as proflavine, and eosin are listed. In addition, magnesium (Mg), zinc (Zn), cadmium (Cd), tin (S n), platinum (Pt), indium (In), or palladium (Pd) Examples of the metal-containing porphyrin include protoporphyrin. Porphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-fluoride Tin complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (Sn F2 (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride Complex (SnF2(Copro III-4Me)), Octaethylporphyrin-fluoride Tin complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(E tio I)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), etc. Can be obtained.

[0167] In addition, as a thermally activated delayed fluorescent compound composed of one kind of material, a π-electron-rich complex Heterocyclic compounds having a heteroaromatic skeleton and a π-electron deficient heteroaromatic skeleton can also be used. Specifically, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoline) PIC -TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H -Carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl nyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3- [4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4, 5-Diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9 -Dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: A CRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl 10-phenyl-10H,10'H-spiro[phenyl]sulfone (abbreviation: DMAC-DPS) [Acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA) The heterocyclic compound has a π-electron rich heteroaromatic skeleton and a π-electron deficient heteroaromatic skeleton. Since the π-electron deficient complex has a high electron transporting property and hole transporting property, it is preferable. Among the aromatic skeletons, the diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton) or triazine skeleton is preferred because it is stable and has good reliability. Among the heteroaromatic skeletons, the acridine skeleton, the phenoxazine skeleton, the phenothiazine skeleton, The furan skeleton, the thiophene skeleton, and the pyrrole skeleton are stable and reliable. It is preferable that the compound has one or more selected from the group consisting of pyrrole and pyrrole. The skeleton includes an indole skeleton, a carbazole skeleton, and a 9-phenyl-3,3'-biphenyl skeleton. 9H-carbazole skeleton is particularly preferred. The substance in which the heteroaromatic skeleton is directly bonded to the π-deficient heteroaromatic skeleton exhibits the donor property of the π-electron-rich heteroaromatic skeleton. The acceptor properties of the π-electron-deficient heteroaromatic skeleton are both strong, and the singlet excited energy level This is particularly preferred because the difference between the triplet excitation energy level and the triplet excitation energy level becomes small.

[0168] In addition, materials that exhibit thermally activated delayed fluorescence can be independently converted from a triplet excited state to a single excited state by reverse intersystem crossing. The material may be capable of generating a doublet excited state, or may be an exciplex (or The material may be made of multiple materials that form a single layer (also called an exciplex).

[0169] The host material used in the light-emitting layer 140 is a hole transport material and an electron transport material. Fees can be used.

[0170] The host material of the light-emitting layer may be any of the following: For example, tris(8-quinolinolato)aluminum(III) (abbreviation: Alq3), Tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), Bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq 2) Bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum (III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq ), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPB O), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBT Z), 2-(4-biphenylyl)-5-(4-tert-butylphenyl )-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(p-ter t-Butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: O XD-7), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butyl) phenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2',2''-(1,3, 5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: T PBI), Bathocuproine (abbreviation: BCP), 9-[4-(5-phenyl-1,3,4 -Oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11) Which heterocyclic compound, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl 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 Examples of aromatic amine compounds include aromatic amine compounds such as phenylamino]biphenyl (abbreviation: BSPB). Anthracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, dibenzo [g,p]Chrysene derivatives and other condensed polycyclic aromatic compounds are included. -Diphenylanthracene (abbreviation: DPAnth), N,N-diphenyl-9-[4-( 10-Phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation : CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (abbreviation :DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-(1 0-Phenyl-9-anthryl)phenyl]phenyl}-9H-carbazole-3-amine PCAPBA, 2PCAPA, 6,12-dimethoxy-5,11-diphenyl Luchrysene, DBC1, 9-[4-(10-phenyl-9-anthracenyl)phenyl] -9H-Carbazole (abbreviation: CzPA), 3,6-diphenyl-9-[4-(10-phenyl [phenyl-9-anthryl]phenyl]-9H-carbazole (abbreviation: DPCzPA), ,10-Bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,1 0-Di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,1 0-Di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9,9'-bianthri BANT, 9,9'-(stilbene-3,3'-diyl)diphenanthrene (abbreviation: DPNS), 9,9'-(stilbene-4,4'-diyl)diphenanthrene ( Abbreviated as DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviated as TPB3), etc. Among these and various other substances, the energy gap of the light-emitting material is One or more materials with an energy gap larger than the gap are selected and used. In addition, when the light-emitting material is a phosphorescent compound, the host material may be a All that is required is to select a substance whose triplet excitation energy is greater than the triplet excitation energy.

[0171] In addition, when multiple materials are used as the host material of the light-emitting layer, two types of materials that form an exciplex are In this case, it is preferable to use a combination of various carrier transport materials. However, in order to efficiently form an exciplex, it is necessary to use an electron transporting material and a positive Combining with a hole transporting material is particularly preferred.

[0172] This is because an exciplex is formed by combining an electron transport material and a hole transport material. When the host material is used, the mixing ratio of the electron transport material and the hole transport material is adjusted. This makes it easy to optimize the carrier balance between holes and electrons in the light-emitting layer. By optimizing the carrier balance of holes and electrons in the light-emitting layer, By suppressing the bias of the area where recombination occurs, As a result, the reliability of the light-emitting element can be improved.

[0173] Electron transport materials include metal complexes containing zinc or aluminum, and nitrogen-containing heteroaromatic compounds. A π-electron deficient heteroaromatic compound such as the compound Bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq 2) Bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum (III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq ), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPB O), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBT Z) and 2-(4-biphenylyl)-5-(4-tert-butylphenyl) 3-(4-biphenylyl)-4-oxadiazole (abbreviation: PBD), -Phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation :TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxo Sadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl- 1,3,4-Oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: C O11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl -1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophene- 4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBI Heterocyclic compounds with azole skeletons such as 2-[3-(dibenzothiophene)m-II] and 2mDBTPDBq -II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibe Benzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9 H-Carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (Abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole -9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-II I) 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quino Xaline (abbreviation: 7mDBTPDBq-II) and 6-[3-(dibenzothiophene -4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq- II), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation : 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pi Rimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carba 4,6mCzP2Pm, 4-{3- [3'-(9H-carbazol-9-yl)]biphenyl-3-yl}benzofuro[3, 2-d]pyrimidine (abbreviation: 4mCzBPBfpm) and other heterocycles with a diazine skeleton Compounds such as 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H- Carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine ( Abbreviation: PCCzPTzn), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl] Nyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2,4,6- Triazines such as tris(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3Tz) Heterocyclic compounds with an aryl skeleton and 3,5-bis[3-(9H-carbazol-9-yl] )phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl Heterocyclization of pyridine skeletons such as TmPyPB Among the above, heterocyclic compounds having a diazine skeleton and a triazine skeleton are preferred. Heterocyclic compounds having a pyridine skeleton and heterocyclic compounds having a pyridine skeleton are preferred because of their excellent reliability. Heterocyclic compounds with azine (pyrimidine and pyrazine) and triazine skeletons are known to be effective in electron transport. It has high transmission properties and also contributes to reducing driving voltage.

[0174] As hole transport materials, π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives and indium arsenide derivatives) are used. 2-[Dole derivatives] or aromatic amines can be suitably used. N-(9-phenylcarbazol-3-yl)-N-phenylamino]spiro-9,9' -Bifluorene (abbreviation: PCASF), 4,4',4''-tris[N-(1-naphthyl )-N-Phenylamino]triphenylamine (abbreviation: 1-TNATA), 2,7-bis [N-(4-diphenylaminophenyl)-N-phenylamino]-spiro-9,9'- Bifluorene (abbreviation: DPA2SF), N,N'-bis(9-phenylcarbazole-3 -yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N -(9,9-Dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenyl Diphenylamine (abbreviation:DPNF), N,N',N''-triphenyl-N,N',N''-triphenyl Tris(9-phenylcarbazol-3-yl)benzene-1,3,5-triamine (abbreviation :PCA3B), 2-[N-(9-phenylcarbazol-3-yl)-N-phenyla amino]spiro-9,9'-bifluorene (abbreviation: PCASF), 2-[N-(4-diphenyl N-phenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPASF), N,N'-bis[4-(carbazol-9-yl)phenyl]-N,N' -Diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), 4,4'-Bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NP B) N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl] phenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(4-diphenyl N-phenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4' -Bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]bi Phenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl) 4-phenyl-3'-(9-phenyl)triphenylamine (abbreviation: BPAFLP) Fluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), N-(9,9- Dimethyl-9H-fluoren-2-yl)-N-{9,9-dimethyl-2-[N'-phenyl N-(9,9-dimethyl-9H-fluoren-2-yl)amino]-9H-fluorenyl Oren-7-yl}phenylamine (abbreviation: DFLADFL), 3-[N-(9-phenyl [N-phenylamino]-9-phenylcarbazole (abbreviation :PCzPCA1), 3-[N-(4-diphenylaminophenyl)-N-phenylamine No]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-bis[N-(4- Diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation PCzDPA2), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl {N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation :DNTPD), 3,6-bis[N-(4-diphenylaminophenyl)-N-(1-na 3,6-bis(phenyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), [N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenyl Carbazole (abbreviation: PCzPCA2), 4-phenyl-4'-(9-phenyl-9H- Carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-di Phenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine PCBBi1BP, 4-(1-naphthyl)-4'-(9-phenyl-9H- Carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di( 1-Naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenyl PCBNBB, 3-[N-(1-naphthyl)-N-(9-phenylcarbamoyl) carbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) , 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-carbazol-3-yl)phenyl]spiro-9,9' -Bifluorene-2-amine (abbreviation: PCBASF), N-(4-biphenyl)-N-( 9,9-Dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazole -3-amine (abbreviation: PCBiF), N-(1,1'-biphenyl-4-yl)-N-[ 4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl- Contains aromatic amine skeleton such as 9H-fluorene-2-amine (abbreviation: PCBBiF) Compounds such as 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di (N-Carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenyl phenyl)-9-phenylcarbazole (abbreviation: CzTP), 9-phenyl-9H-3- (9-phenyl-9H-carbazol-3-yl)carbazole (abbreviation: PCCP), etc. Compounds with a carbazole skeleton such as 4,4',4''-(benzene-1,3,5-triphenylphosphine) 2,8-diphenyl)tri(dibenzothiophene) (abbreviation: DBT3P-II) -4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene Fluorene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluorene- 9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV) Compounds with thiophene skeletons such as 4,4',4''-(benzene-1,3,5- triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9 -phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation :mmDBFFLBi-II) and other compounds having a furan skeleton. Among them, compounds with aromatic amine skeletons and compounds with carbazole skeletons have high reliability. In addition, the hole transporting property is high, and this contributes to reducing the driving voltage, which is preferable.

[0175] The combination of the host material that forms the exciplex is not limited to the above-mentioned compounds. It is a combination that can transport carriers without being disturbed and can form an exciplex. The emission of the exciplex occurs in the absorption band on the longest wavelength side of the absorption spectrum of the luminescent material (luminescent material (absorption corresponding to the transition from the singlet ground state to the singlet excited state of Other materials may also be used.

[0176] Furthermore, a thermally activated delayed fluorescent material may be used as the host material for the light-emitting layer.

[0177] In addition, the electron transport material used in the light emitting layer is the same as the electron transport material used in the electron injection layer. This allows the light-emitting element to be easily manufactured, and the light-emitting element can be easily manufactured. The manufacturing costs of the optical element can be reduced.

[0178] <Electron transport layer and buffer layer> The electron transport layer 118 and the buffer layer 127 are layers containing a substance with a high electron transport property. The organic compounds that can be used for the electron transport layer 118 and the buffer layer 127 include quinolinol, The ligands are benzoquinoline, oxazole, or thiazole. Metal complexes, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives , pyridine derivatives, bipyridine derivatives, etc. The compounds that can be used are those having a function of interacting with metals at the tridentate or tetradentate positions. Organic compounds may also be used.

[0179] The above-mentioned quinoline ligand, benzoquinoline ligand, oxazole ligand, or thiazo Metal complexes with aryl ligands, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, Specific examples of pyridine derivatives, bipyridine derivatives include Alq3, Al mq3, BeBq2, BAlq, bis(8-quinolinolato)zinc(II) (abbreviation: Znq ), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPB O), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBT Metal complexes such as 2-(4-biphenylyl)-5-(4 -tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1, 3-Bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2 -yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxo sadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 3-( 4'-tert-butylphenyl)-4-phenyl-5-(4''-biphenylyl)-1 ,2,4-Triazole (abbreviation: TAZ), 3-(4-tert-butylphenyl)-4 -(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole (abbreviation Name: p-EtTAZ), 4,4'-bis(5-methylbenzoxazol-2-yl)s BzOS, 2,2',2''-(1,3,5-benzenetriyl) Tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(diphenyl Benzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole ( Heterocyclic compounds with an azole skeleton, such as 2-[3- (Dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl 2mDBTBPDBq-II , 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f ,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl- 9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2 CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzyl quinoxaline (abbreviation: 7mDBTPDBq-II) and 6-[3-( Dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6 mDBTPDBq-II), 4,6-bis[3-(phenanthren-9-yl)phenyl ]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothie nyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[ 3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2 Pm), 4-{3-[3'-(9H-carbazol-9-yl)]biphenyl-3-yl }Diazines such as benzofuro[3,2-d]pyrimidine (abbreviation: 4mCzBPBfpm) Heterocyclic compounds with a skeleton and 2-{4-[3-(N-phenyl-9H-carbazole- 3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3 ,5-triazine (abbreviation: PCCzPTzn), 2,4,6-tris[3'-(pyridine -3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyT z), 2,4,6-tris(2-pyridyl)-1,3,5-triazine (abbreviation: 2Py3 Heterocyclic compounds with triazine skeletons such as 3,5-bis[3-(9H-carbazolyl) 35DCzPPy, 1,3,5-Triphenyl-9-yl)pyridine Tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), Bathocuproi BCP, 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1 Heterocyclization with pyridine skeleton such as 10-phenanthroline (abbreviation: NBPhen) Among the above, heterocyclic compounds having a diazine skeleton and a triazine skeleton are preferred. Heterocyclic compounds having a pyridine skeleton and heterocyclic compounds having a pyridine skeleton are preferred because of their excellent reliability. Heterocyclic compounds with azine (pyrimidine and pyrazine) and triazine skeletons are known to be effective in electron transport. The materials mentioned here have a high conductivity and contribute to reducing the driving voltage. -6 cm 2 A material that has an electron mobility of 1000V or more. As long as the material satisfies the requirements, the electron injection layer 130 may be made of a material other than those mentioned above.

[0180] In addition, the electron transport layer 118 and the buffer layer 127 may be made of the above-mentioned materials, rather than being made of a single layer. Two or more layers made of such a material may be laminated.

[0181] In addition, a layer for controlling the movement of electron carriers is provided between the electron transport layer 118 and the light emitting layer 140. This is a material having a high electron transporting property and a material having a high electron trapping property. A layer in which a small amount of Zn is added, which suppresses the movement of electron carriers, thereby reducing carrier dispersion. This structure prevents electrons from penetrating the light-emitting layer. This is highly effective in suppressing problems caused by the above-mentioned problems (such as a decrease in element life).

[0182] In addition, the electron transporting material used in the electron transport layer is the same as the electron transporting material used in the electron injection layer. The electron transporting material used in the electron transport layer may be the same as that used in the light emitting layer. The same material as the electron transport material used in the present invention can be used. This allows the steps to be easily performed, thereby reducing the manufacturing cost of the light-emitting device.

[0183] The above-mentioned hole injection layer, hole transport layer, light emitting layer, electron transport layer, and electron injection layer are These are deposition methods (including vacuum deposition), inkjet methods, coating methods, gravure printing, etc. In addition, the hole injection layer, the hole transport layer, the light emitting layer, and the electron transport layer can be formed. In addition to the above-mentioned materials, the electron injection layer may be made of inorganic compounds such as quantum dots or polymers. Compounds (oligomers, dendrimers, polymers, etc.) may also be used.

[0184] The quantum dots are classified into colloidal quantum dots, alloy quantum dots, and core-shell quantum dots. In addition, a group 2 and a group 16, a group 13 and a group 14, and a core type quantum dot may be used. Contains element groups 15, 13 and 17, 11 and 17, or 14 and 15 Quantum dots may also be used. Alternatively, cadmium (Cd), selenium (Se), zinc (Zn ), sulfur (S), phosphorus (P), indium (In), tellurium (Te), lead (Pb), gallium (Ga), Quantum dots containing elements such as Ga, Arsenic, and Aluminum are used. It's fine.

[0185] Examples of liquid media used in wet processes include methyl ethyl ketone, cyclohexane, etc. Ketones such as xanone, fatty acid esters such as ethyl acetate, halogens such as dichlorobenzene Hydrocarbons, aromatics such as toluene, xylene, mesitylene, and cyclohexylbenzene Hydrocarbons, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, N,N-dimethyl Use organic solvents such as dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). It is possible.

[0186] Examples of polymer compounds that can be used in the light-emitting layer include poly[2-methoxy]phenylene. [MeH] -PPV), polyphenylenes such as poly(2,5-dioctyl-1,4-phenylenevinylene), Poly(9,9-di-n-octylfluorenyl-2,7 -diyl) (abbreviation: PF8), poly[(9,9-di-n-octylfluorenyl-2,7 -diyl)-alt-(benzo[2,1,3]thiadiazole-4,8-diyl)](abbreviation Name: F8BT), poly[(9,9-di-n-octylfluorenyl-2,7-diyl)- alt-(2,2'-bithiophene-5,5'-diyl)] (abbreviated as F8T2), poly[( 9,9-Dioctyl-2,7-Divinylenefluorenylene)-alt-(9,10-An thracene)], poly[(9,9-dihexylfluorene-2,7-diyl)-alt-( Polyfluorene derivatives such as poly(3-hexyl) Polyalkylthiophene (PAT) derivatives such as poly(3-methylthiophene) (abbreviation: P3HT), These polymer compounds and poly(N-vinyl carbazole) (abbreviation: PVK), poly(2-vinylnaphthalene), poly[bis(4- Polymerization of 2,4,6-trimethylphenylamine (abbreviation: PTAA) The compound may be doped with a light-emitting low molecular weight compound and used in the light-emitting layer. As the material, the fluorescent compounds listed above can be used.

[0187] The electrode 101 and the electrode 102 function as an anode or a cathode of the light-emitting element. The electrode 101 and the electrode 102 may be made of a metal, an alloy, a conductive compound, or a mixture or laminate of these. It can be formed using the above.

[0188] One of the electrodes 101 and 102 is made of a conductive material that has a function of reflecting light. The conductive material is preferably aluminum (Al) or a composite material containing Al. Examples of alloys containing Al include Al and L (L is titanium (Ti), neodymium (Nd)). (representing one or more of Nd, Ni, and La) Examples of the alloy include an alloy containing Al and Ti, or an alloy containing Al, Ni and La. Aluminum has low resistance and high light reflectance. Since aluminum is abundant and inexpensive, the manufacturing cost of light-emitting elements using aluminum is low. In addition, silver (Ag) is a good electrode material because of its high light reflectance. Ag is a transition metal in group 11, and is one embodiment of the present invention. When Ag is used as the cathode of a light-emitting device using Ag as the electron injection layer, the electrode and the electron injection layer This is preferable because it improves the adhesion between the two. Or Ag and N (N is yttrium (Y), Nd, Magnesium (Mg), Ytterbium (Yb), Al, Ti, Gallium (Ga), Zinc (Zn), indium (In), tungsten (W), manganese (Mn), tin (Sn) , Iron (Fe), Ni, Copper (Cu), Palladium (Pd), Iridium (Ir), or Gold (Au)) may be used. Examples of the alloy include an alloy containing silver, palladium and copper, an alloy containing silver and copper, and an alloy containing silver and magnesium. Alloys containing silver and nickel, alloys containing silver and gold, alloys containing silver and ytterbium, etc. Others include tungsten, chromium (Cr), molybdenum (Mo), copper, titanium Transition metals such as lanthanides can be used.

[0189] The light emitted from the light-emitting layer is emitted through one or both of the electrodes 101 and 102. Therefore, at least one of the electrodes 101 and 102 is transparent to light. It is preferable that the conductive material is a material having a permeability function. The visible light transmittance is 40% or more and 100% or less, preferably 60% or more and 100% or less, The resistivity is 1×10 -2 Examples include conductive materials with a resistance of Ω·cm or less.

[0190] In addition, the electrodes 101 and 102 have a function of transmitting light and a function of reflecting light. The conductive material may be formed of a conductive material having a visible light reflectance of 20 or more. % or more and 80% or less, preferably 40% or more and 70% or less, and the resistivity is 1×10 -2 Conductive materials with a capacitance of Ω·cm or less include conductive metals, alloys, and conductive materials. The insulating layer can be formed by using one or more of the following compounds: Indium Tin Oxide (ITO), silicon or silicon oxide Indium tin oxide (ITSO), indium oxide-zinc oxide (Indium um Zinc Oxide), titanium-containing indium tin oxide, indium Metals such as indium oxide containing titanium oxide, tungsten oxide, and zinc oxide Oxides can be used. In addition, the thickness of the oxide is preferably within a range of 1 nm to 30 nm. A metal thin film having a thickness of 1 μm or less can be used. Examples of metals include Ag, Alloys such as Ag and Al, Ag and Mg, Ag and Au, and Ag and Yb can be used.

[0191] In this specification and the like, a material having a function of transmitting light is a material having a function of transmitting visible light. Any material having the above and having electrical conductivity may be used, and examples thereof include ITO. In addition to oxide conductors, oxide semiconductors and organic conductors containing organic substances are also included. The organic conductor containing the electron donor is, for example, a mixture of an organic compound and an electron donor. Examples of such materials include composite materials made by mixing organic compounds and electron acceptors. Alternatively, an inorganic carbon-based material such as graphene may be used. The rate is preferably 1×10 5 Ω cm or less, more preferably 1×10 4 Ω cm The following is the result.

[0192] In addition, by laminating a plurality of the above materials, one or both of the electrodes 101 and 102 can be formed. may form both.

[0193] In order to improve the light extraction efficiency, the electrode is in contact with the light transmitting electrode. A material having a higher refractive index than the electrode may be used. As long as the material has the function of providing the above, it may be a material that is conductive or not. For example, in addition to the oxide conductors described above, oxide semiconductors and organic materials can be used. The organic material may be, for example, a light-emitting layer, a hole-injecting layer, a hole-transporting layer, an electron-transporting layer, or an electron The materials listed for the electron injection layer are also available. Inorganic carbon-based materials and metals that are light-transmitting are also available. A thin film may also be used, and multiple layers of several nanometers to several tens of nanometers may be laminated.

[0194] When the electrode 101 or the electrode 102 functions as a cathode, the work function is small. It is preferable to have a material with a refractive index of 3.8 eV or less.

[0195] In addition, when the electrode 101 or the electrode 102 is used as an anode, the electrode having a large work function (4. 0 eV or more) materials are preferably used.

[0196] The electrodes 101 and 102 are made of a conductive material having a function of reflecting light and a conductive material having a function of transmitting light. In this case, the electrode 101 and the electrode 102 may be laminated with a conductive material having a permeability function. 02 can resonate light of a desired wavelength from each light-emitting layer and intensify the light of the desired wavelength. This is preferable because it has a function of adjusting the optical path length so that the optical path length can be adjusted.

[0197] The electrode 101 and the electrode 102 are formed by a method such as sputtering, vapor deposition, printing, or coating. , MBE (Molecular Beam Epitaxy) method, CVD method, pulse laser The deposition method, ALD (Atomic Layer Deposition) method, etc. are used appropriately. It is possible.

[0198] <Substrate> In addition, the light-emitting element according to one embodiment of the present invention is provided on a substrate made of glass, plastic, or the like. Regarding the order of fabrication on the substrate, the layers may be stacked in order from the electrode 101 side. They may be laminated in order from the pole 102 side.

[0199] The substrate on which the light-emitting element according to one embodiment of the present invention can be formed is, for example, glass or quartz. A flexible substrate may be used. The substrate is a flexible substrate, such as polycarbonate. Examples of the substrate include plastic substrates made of polyacrylate and polyarylate. In addition, a film made by vapor deposition may be used in the manufacturing process of the light-emitting element and the optical element. Any other material may be used as long as it functions as a support in the light-emitting device. Anything that has the function of protecting the element and the optical element may be used.

[0200] For example, in this specification, a light emitting element can be formed using various substrates. The type of the substrate is not particularly limited. An example of the substrate is a semiconductor substrate (e.g., a single crystal crystal substrate or silicon substrate), SOI substrate, glass substrate, quartz substrate, plastic substrate, gold Metallic substrate, stainless steel substrate, substrate with stainless steel foil, tungsten Tungsten substrate, substrate with tungsten foil, flexible substrate, laminated film, fiber These include cellulose nanofibers (CNFs), papers, and base films that contain such materials. Examples of glass substrates include barium borosilicate glass, aluminoborosilicate glass, and Soda lime glass, etc. Flexible substrates, laminated films, base films, etc. Examples of such materials include polyethylene terephthalate (PET), Polyethylene naphthalate (PEN), polyethersulfone (PES), polytetrafluoroethylene Examples of plastics include fluoroethylene (PTFE). Resins such as acrylic, etc., or polypropylene, polyester, etc. Examples include polyvinyl fluoride or polyvinyl chloride. Alternatively, an example is polyamide. , polyimide, aramid, epoxy, inorganic vapor deposition film, or paper.

[0201] In addition, a flexible substrate may be used as the substrate, and the light emitting element may be formed directly on the flexible substrate. Alternatively, a release layer may be provided between the substrate and the light-emitting element. After a part or all of a chip is completed, it is separated from the board and used to transfer it to another board. In this case, the light-emitting element can be transferred onto a substrate having poor heat resistance or a flexible substrate. The above-mentioned peeling layer has a laminated structure of an inorganic film such as a tungsten film and a silicon oxide film. Alternatively, a configuration in which a resin film such as polyimide is formed on a substrate can be used.

[0202] That is, a light emitting element is formed using a certain substrate, and then the light emitting element is transferred to another substrate, The light emitting element may be disposed on another substrate. In addition to the above mentioned substrates, cellophane substrates, stone substrates, wood substrates, fabric substrates (natural fibers (silk, cotton, Hemp), synthetic fibers (nylon, polyurethane, polyester) or regenerated fibers (acetate (including cellulose, cupra, rayon, recycled polyester, etc.), leather substrate, rubber substrate, etc. By using these substrates, light-emitting elements that are not easily broken and have high heat resistance can be produced. The light emitting element may be a small light emitting element, a light emitting element that is lighter in weight, or a light emitting element that is thinner.

[0203] Also, for example, a field effect transistor (FET) is formed on the above-mentioned substrate, and the FET and The light emitting element 150 may be fabricated on the electrically connected electrodes. In this way, an active matrix display device that controls the driving of light emitting elements can be manufactured.

[0204] The structure shown in this embodiment mode can be used in appropriate combination with other embodiment modes. Cut.

[0205] (Embodiment 2) In this embodiment mode, a light-emitting element having a different structure from that of the light-emitting element shown in Embodiment 1 is used. The light emitting mechanism of the light emitting device will be described below with reference to FIG. In this case, the same hatch pattern is used for the parts having the same functions as those shown in FIG. 1(A). In addition, parts having similar functions are given similar reference symbols. However, detailed description thereof may be omitted.

[0206] <Configuration Example 4 of Light-Emitting Element> FIG. 3 is a schematic cross-sectional view of the light emitting element 250a and the light emitting element 250b.

[0207] The light emitting element 250a and the light emitting element 250b are formed by providing an electrode 101 and an electrode 102 on a substrate 200. , an electrode 103, and an electrode 104. In addition, between the electrode 101 and the electrode 102, and At least a light emitting layer is formed between the electrode 102 and the electrode 103 and between the electrode 102 and the electrode 104. The light-emitting unit 106 and the light-emitting unit 108 are connected to an electron injection layer 130. A charge generating layer 115 is provided between the unit 106 and the light emitting unit 108. The light unit 106 and the light emitting unit 108 may be of the same construction or of different constructions.

[0208] The charge generating layer 115 sandwiched between the light emitting unit 106 and the light emitting unit 108 is, for example, When a voltage is applied between the electrode 101 and the electrode 102, electrons are injected into one of the light-emitting units, It is sufficient if the electrode injects holes into the other light-emitting unit. For example, in FIG. When a voltage is applied so that the potential of electrode 02 is higher than the potential of electrode 101, a charge is generated. Layer 115 injects electrons into light-emitting unit 106 and holes into light-emitting unit 108. .

[0209] The light-emitting unit 106 includes, for example, a hole injection layer 111, a hole transport layer 112, and a light-emitting layer The light-emitting unit 108 also includes a hole-injecting layer 140 and an electron-transporting layer 113. layer 116, a hole transport layer 117, a light emitting layer 170, an electron transport layer 118, and an electron injection layer 1 19 and,

[0210] Here, as shown in FIG. 3, the electron injection layer 130 is adjacent to the electron transport layer 113 and is a light emitting unit. It is preferable that the insulating layer 108 is provided between the electron transport layer 113. Also, as shown in FIG. The charge generating layer 115 is adjacent to the electron injection layer 130 and is in contact with the light emitting unit. It is preferable that the light emitting unit 108 is provided between the light emitting unit 108 and the light emitting unit 109. 06 can efficiently transport electrons.

[0211] In this embodiment, the electrodes 101, 103, and 104 are used as anodes. In the following description, the electrode 102 is assumed to be a cathode. In other words, the electrodes 101, 103, and 104 are cathodes. However, the electrode 102 may be an anode, and the layers between the electrodes may be stacked in the reverse order. That is, the light-emitting unit 106 is composed of a hole injection layer 111, a hole transport layer 112, and a light-emitting layer 113 from the anode side. The light emitting layer 140, the electron transport layer 113, and the electron injection layer 130 may be stacked in this order. The light-emitting unit 108 includes, from the anode side, a hole injection layer 116, a hole transport layer 117, and a light-emitting The layer 170, the electron transport layer 118, and the electron injecting layer 119 may be stacked in this order.

[0212] The configuration of the light emitting element 250a and the light emitting element 250b is not limited to the configuration shown in FIG. At least the light-emitting layer 140, the light-emitting layer 170, the charge generating layer 115, and the electron injection layer 1 30, a hole injection layer 111, a hole injection layer 116, a hole transport layer 112, and a hole transport layer 11 7. The electron transport layer 113, the electron transport layer 118, and the electron injection layer 119 may each be provided, It is not necessary to have it.

[0213] Furthermore, a layer may be formed between the pair of electrodes according to its function, and is not limited thereto. That is, between the pair of electrodes, a hole or electron injection barrier is provided to reduce the hole or electron injection barrier. Improve transportability, inhibit hole or electron transportability, or suppress quenching by electrodes The insulating layer 11 may have a layer having a function of suppressing the adhesion of the insulating layer 11 or the like.

[0214] In addition, as in the case of the light-emitting unit 108, the surface of the light-emitting unit on the anode side is connected to the charge generating layer 115. When in contact with the charge generating layer 115, the charge generating layer 115 also serves as a hole injection layer for the light emitting unit 108. Therefore, it may not be necessary to provide a hole injection layer in the light-emitting unit. do.

[0215] In addition, in FIG. 3, the light emitting element having two light emitting units has been described. The light emitting element 250a and the light emitting element 250b may be formed by stacking two or more light emitting units. As shown in 250b, a plurality of light-emitting units are arranged between a pair of electrodes and separated by charge generating layers. This makes it possible to achieve high-brightness light emission while keeping the current density low, and also to produce a light-emitting element with a long life. In addition, a light-emitting element with low power consumption can be realized.

[0216] In the light emitting element 250a, the electrodes 101, 103, and 104 reflect visible light. The electrode 102 has a function of transmitting visible light. In FIG. 0b, the electrodes 101, 103, and 104 have a function of transmitting visible light. The electrode 102 has a function of reflecting visible light.

[0217] Therefore, the light emitted by the light emitting element 250a is emitted to the outside through the electrode 102. The light emitted by the element 250b is emitted to the outside through the electrodes 101, 103, and 104. However, one aspect of the present invention is not limited to this. It may be a light emitting element that extracts light both above and below the substrate.

[0218] The electrode 101 includes a conductive layer 101a and a conductive layer 101b that is in contact with the conductive layer 101a. The electrode 103 includes a conductive layer 103a and a conductive layer 103b that is in contact with the conductive layer 103a. The electrode 104 has a conductive layer 104a and a conductive layer 103b on the conductive layer 104a. and a conductive layer 104b.

[0219] The conductive layer 101b, the conductive layer 103b, and the conductive layer 104b have a function of transmitting visible light. In the light-emitting element 250a, the conductive layer 101a, the conductive layer 103a, and the conductive layer 1 The conductive layer 104a has a function of reflecting visible light. The conductive layer 01a, the conductive layer 103a, and the conductive layer 104a have a function of transmitting visible light.

[0220] The light emitting element 250a shown in FIG. 3A and the light emitting element 250b shown in FIG. 3B have an electrode The region 222B sandwiched between the electrodes 101 and 102, and the region 222B sandwiched between the electrodes 102 and 103 and a region 222R sandwiched between the electrode 102 and the electrode 104. The partition wall 145 has an insulating property. The partition wall 145 is provided between the electrode 101 and the electrode 1 The separator 145 covers the end of the electrode 103 and the end of the electrode 104 and has an opening overlapping the electrode. By this, the electrodes on the substrate 200 in each region can be separated into islands. It becomes Noh.

[0221] In FIG. 3, the hole injection layer 111, the hole injection layer 116, the hole transport layer 112, Hole transport layer 117, light emitting layer 140, light emitting layer 170, electron transport layer 113, electron transport layer 118, The electron injection layer 119, the charge generation layer 115, and the electrode 102 are not separated from each other in each region. Although the example shows a common arrangement, they may be provided separately in each region.

[0222] In the light-emitting element 250a and the light-emitting element 250b according to one embodiment of the present invention, Between the pair of electrodes (electrode 101 and electrode 102), the pair of electrodes (electrode 102 and and electrode 103) and between a pair of electrodes in region 222R (electrode 102 and electrode 104). By applying a voltage, electrons are injected from the cathode into the electron injection layer 119 and from the anode. When holes are injected from the junction into the hole injection layer 111, a current flows. Electrons are injected from the charge generating layer 115 into the electron injection layer 130, and holes are injected from the charge generating layer 115 into the charge injection layer 130. are injected into the hole injection layer 116. Then, the injected carriers (electrons and holes) recombine. The light-emitting layer 140 and the light-emitting layer 141 each having a light-emitting material are formed by combining the light-emitting layer 140 and the light-emitting layer 141. At 70, carriers (electrons and holes) recombine to form excitons, and the light-emitting layer 1 The light-emitting material contained in the light-emitting layer 40 and the light-emitting layer 170 is excited, and light is emitted from the light-emitting material. .

[0223] The light-emitting layers 140 and 170 are purple, blue, blue-green, green, yellow-green, yellow, and yellow-orange. The present invention has one or more luminescent materials selected from the group consisting of luminescent materials that emit orange or red light. This would be preferable.

[0224] The light-emitting layer 140 and the light-emitting layer 170 may be configured as a two-layer laminate. The light-emitting layer contains two types of compounds, a first compound and a second compound, that have the function of exhibiting different colors. By using each of the light-emitting materials, multiple lights can be emitted simultaneously. The light emitted by the light-emitting layer 140 and the light-emitting layer 170 is adjusted so as to produce a white color or a color close to white. It is preferable to select a light-emitting material for use in the optical layer.

[0225] In addition, the light-emitting layer 140 and the light-emitting layer 170 may have a structure in which three or more layers are laminated. Layers that do not have optical material may be included.

[0226] In addition, the light emitting element 250a and the light emitting element 250b are formed in the regions 222B, 222G, and In the direction in which the light emitted from the region 222R is extracted, the optical element 224B and the optical element The substrate 220 has a substrate 220 on which a semiconductor device 224G and an optical element 224R are provided. The light emitted from the region 222B is emitted to the outside of the light emitting element through each optical element. The light emitted from the region 222G is output through the optical element 224B. The light emitted through element 224G and emitted from region 222R passes through optical element 224R. and then ejected.

[0227] In addition, the optical elements 224B, 224G, and 224R are For example, the optical element 224B has a function of selectively transmitting light of a specific color. The light emitted from the region 222B through the optical element 22 is blue light. The light emitted from the area 222G via the optical element 4G is green light. The light emitted from the region 222R via the element 224R is red light.

[0228] In addition, in FIG. 3(A) and FIG. 3(B), the light emitted from each region via each optical element is The light that appears in the image is classified as blue (B), green (G), and red (R). The light emitting element 250a shown in FIG. The light-emitting element 250b shown in FIG. 3B is a bottom-emission type light-emitting element. It is a cushion type light emitting element.

[0229] In addition, a light-shielding layer 223 is provided between each optical element. The light-shielding layer 223 is formed to prevent light from entering from adjacent regions. It is to be noted that the light shielding layer 223 may not be provided. In addition, any one of the optical elements 224B, 224G, and 224R The optical element 224B, the optical element 224G, or the like may be omitted. Alternatively, the optical element 224R is not provided, so that the light extraction efficiency of the light emitting element is improved. The rate can be increased.

[0230] The charge generating layer 115 is formed by adding an electron acceptor to a hole transporting material. or an electron transport material to which an electron donor (donor) has been added, It can be formed.

[0231] Here, in order to reduce the driving voltage of the light-emitting element, the charge generating layer 115 to the electron transport layer 1 The electron transport layer 113 is formed by lowering the barrier for electron injection into the charge generation layer 115. Therefore, the charge generation layer 115 and the electron It is preferable to provide an electron injection layer 130 between the transport layers 113. Since the injection layer 130 is required to have high electron injection properties, the electron injection layer is formed of lithium (Li) or Alkaline metals such as cesium (Cs) and their compounds, such as calcium (Ca) Alkaline earth metals and their compounds are used. However, the metals and their compounds are not electron-injected. When the electrode 103 is used as the interfacial layer 130, for example, as shown in FIG. When a voltage is applied to the region 222G and a current flows through the electron injection layer 130 and the electron transport layer 113, As a result, a current also flows through the region 222B and the region 222R adjacent to the region 222G. G emits light, but also the adjacent regions 222B and 222R emit light. In addition, in the region 222 in FIG. G, the current flowing through region 222R and region 222B is represented by solid arrows.

[0232] When crosstalk occurs in the light emitting element, light is emitted from a desired area (e.g., area 222G). Not only does the light emit from the first region, but also from other regions (e.g., regions 222B and 222R). Therefore, the color purity of the light emitted by the light emitting element 250a and the light emitting element 250b may decrease. or the emission intensity may decrease.

[0233] The crosstalk occurs when the electron injection layer 130 is sandwiched between the charge generation layer 115 and the electron transport layer 113. The alkali metal, alkaline earth metal, or compound thereof used in the electron transport layer 113 The conductivity of the electron transport layer 113 (particularly the conductivity in the direction perpendicular to the voltage application direction) is improved. In particular, metals with small atomic numbers such as Li and Ca and their compounds When the compound is used in the electron injection layer 130, the metal with the lower atomic number is Therefore, in order to suppress crosstalk, the electron injection layer 130 should be made of Al. It is preferable that the electron injection layer 130 does not contain potassium metal and alkaline earth metal. When no alkali metal, alkaline earth metal, or compound thereof is used, the charge generating layer 1 Since the barrier for electron injection from 15 to the electron transport layer 113 becomes high, electrons are injected into the electron transport layer 113. This may result in a higher driving voltage for the light-emitting device or a lower light-emitting efficiency. do.

[0234] Therefore, the driving voltage of the light emitting element can be reduced, the light emitting efficiency can be improved, and crosstalk can be suppressed. In order to achieve this, the compound must have excellent electron injection properties and, when mixed with an organic compound, must be able to diffuse through the organic compound. It is preferable to use a metal that is difficult to disperse in the electron injection layer 130. Metals with large atomic radii are preferred as metals that are difficult to dissolve. preferable.

[0235] Here, the light-emitting element of one embodiment of the present invention has a function of interacting with a metal at a tridentate or tetradentate site. The metal contains an atom belonging to Groups 3 to 13 of the organic compound. Therefore, in one embodiment of the present invention, a metal having a large atomic radius or a large amount of hydrogen can be preferably used. It is possible to provide a light-emitting element in which crosstalk is suppressed.

[0236] In particular, transition metals have a large atomic weight and are difficult to diffuse in organic compounds, so crosstalk is suppressed. It is possible to provide a light emitting element having such a structure.

[0237] The light-emitting unit 106, the light-emitting unit 108, and the charge generating layer 115 are formed by deposition ( It can be formed by a method such as vacuum deposition, inkjet printing, coating, gravure printing, etc. do.

[0238] Note that the structure described in this embodiment mode may be used in appropriate combination with structures described in other embodiments. There can be.

[0239] (Embodiment 3) In this embodiment, a light-emitting device using the light-emitting element described in Embodiments 1 and 2 is This will be described with reference to FIG. 5(A) and FIG. 5(B).

[0240] FIG. 5(A) is a top view showing a light emitting device, and FIG. 5(B) is a view taken along line AB and line C- This light emitting device is a light emitting device that controls the light emission of a light emitting element. A driving circuit section (source side driving circuit) 601, a pixel section 602, and a driving circuit section (gate The LED driver circuit 603 is a sealing substrate 604, a desiccant 625, and a LED driver circuit 605. is a sealant, and the inside surrounded by the sealant 605 forms a space 607 .

[0241] The lead wiring 608 is connected to the source side driver circuit 601 and the gate side driver circuit 603. The wiring is for transmitting the signals to be input, and the FPC (flexible printed circuit board) is the external input terminal. Video signal, clock signal, start signal, reset signal, etc. from the 609 Although only the FPC is shown here, the FPC has a printed wiring board. Even if a printed wiring board (PWB) is installed, The light emitting device in this specification includes not only the light emitting device itself but also an FPC or PWB. This also includes a light-emitting device to which the

[0242] Next, a cross-sectional structure of the light emitting device will be described with reference to FIG. A driving circuit section and a pixel section are formed on the source side driving circuit section. A circuit 601 and one pixel in a pixel portion 602 are shown.

[0243] The source side driver circuit 601 includes an n-channel TFT 623 and a p-channel TFT 624. The driver circuit is a combination of various CMOS circuits, It may be formed of a MOS circuit or an NMOS circuit. This shows a driver integrated type with a driver circuit formed on the board, but this is not necessarily required. Alternatively, it may be formed externally.

[0244] The pixel section 602 includes a switching TFT 611, a current control TFT 612 and its drain. The pixel includes a first electrode 613 electrically connected to the input. An insulator 614 is formed so as to cover the end of the electrode 613. The insulating layer can be formed by using a photosensitive resin film having a mold.

[0245] In order to improve the coverage of the film formed on the insulator 614, the insulator 614 is The upper end or the lower end is formed to have a curved surface. For example, When photosensitive acrylic is used as the material, it is possible to make only the upper end of the insulator 614 curved. The radius of curvature of the curved surface is preferably 0.2 μm or more and 0.3 μm or less. Either a negative photosensitive material or a positive photosensitive material can be used as the border 614. do.

[0246] An EL layer 616 and a second electrode 617 are formed on the first electrode 613. Here, the material used for the first electrode 613 functioning as an anode is a material having a work function of It is desirable to use a material with a large capacitance. For example, an ITO film or an indium tin oxide film containing silicon. Indium tin oxide film, indium oxide film containing 2wt% to 20wt% zinc oxide, nitride In addition to single-layer films such as titanium film, chromium film, tungsten film, Zn film, and Pt film, titanium nitride film and Lamination with a film mainly composed of aluminum, titanium nitride film and a film mainly composed of aluminum A three-layer structure of a titanium nitride film and a silicon nitride film can be used. The resistance of the anode is low, good ohmic contact can be achieved, and the anode can function as well. This can be done.

[0247] The EL layer 616 is formed by deposition using a deposition mask, inkjet printing, or spin coating. The EL layer 616 can be formed by various methods such as the above. The polymer may be a polymer compound (including an oligomer or a dendrimer).

[0248] Furthermore, a material for a second electrode 617 formed on the EL layer 616 and functioning as a cathode As the material, materials with a small work function (Al, Mg, Li, Ca, or alloys or compounds of these) It is preferable to use a material such as MgAg, MgIn, or AlLi. In the case where the light generated in the EL layer 616 is to be transmitted to the second electrode 617, a film having a thickness of A thin metal film and a transparent conductive film (ITO, 2wt% to 20wt% zinc oxide) Indium oxide containing silicon, indium tin oxide containing silicon, zinc oxide (ZnO, etc.) It is preferable to use a laminate of the above.

[0249] The first electrode 613, the EL layer 616, and the second electrode 617 form a light-emitting element 618. The light emitting element 618 is a light emitting element having the configurations of the first and second embodiments. It is preferable that the pixel portion has a plurality of light emitting elements. In the light emitting device in the embodiment, the light emitting element having the configuration described in the first and second embodiments is The light-emitting element may include both a light-emitting element having a different configuration.

[0250] Furthermore, the sealing substrate 604 is bonded to the element substrate 610 with a sealant 605, A light emitting element is disposed in a space 607 surrounded by a child substrate 610, a sealing substrate 604, and a sealant 605. 618. The space 607 is filled with a filler. The filler may be an inert gas (such as nitrogen or argon), a resin, a desiccant, or both. In some cases, the more formal option is used.

[0251] It is preferable to use epoxy resin or glass frit for the sealing material 605. It is desirable that these materials are as impermeable to moisture and oxygen as possible. The sealing substrate 604 can be a glass substrate, a quartz substrate, or an FRP (Fiber Reinforced Plastic) substrate. rced Plastics), PVF (Polyvinyl fluoride), polyester or A plastic substrate made of acrylic or the like can be used.

[0252] As described above, a light emitting device using the light emitting elements described in the first and second embodiments can be obtained.

[0253] <Light-emitting device configuration example 1> FIG. 6 shows an example of a display device, which includes a light emitting element that emits white light and a coloring layer (color filter). 3 shows a light emitting device having a photodiode formed thereon.

[0254] FIG. 6A shows a substrate 1001, an insulating base film 1002, a gate insulating film 1003, and a gate electrode. 1006, 1007, 1008, a first interlayer insulating film 1020, a second interlayer insulating film 1021 , a peripheral portion 1042, a pixel portion 1040, a driving circuit portion 1041, and a first electrode 102 of a light-emitting element. 4W, 1024R, 1024G, 1024B, partition wall 1026, EL layer 1028, light-emitting element The second electrode 1029, the sealing substrate 1031, the sealant 1032, the red pixel 1044R, the green Shown are color pixels 1044G, blue pixels 1044B, white pixels 1044W, etc.

[0255] In addition, in FIG. 6(A) and FIG. 6(B), colored layers (red colored layer 1034R, green colored layer 10 34G, and a blue colored layer 1034B) are provided on a transparent substrate 1033. A black matrix 1035 may be further provided. The transparent base material 1033 is aligned and fixed to the substrate 1001. The color layer is covered with an overcoat layer 1036. There is light that does not pass through the layers and goes out, and there is light that passes through the colored layers of each color and goes out. The light that does not pass through the colored layer becomes white, and the light that passes through the colored layer becomes red, blue, and green, so the image is created with four color pixels. can be expressed.

[0256] In FIG. 6B, a red colored layer 1034R, a green colored layer 1034G, and a blue colored layer 103 An example in which 4B is formed between the gate insulating film 1003 and the first interlayer insulating film 1020 is shown. As shown in FIG. 6B, the colored layer may be provided between the substrate 1001 and the sealing substrate 1031. stomach.

[0257] In the light emitting device described above, the light is taken in toward the substrate 1001 on which the TFT is formed. The light emitting device has a bottom emission structure, but the light is emitted from the sealing substrate 1031 side. The light emitting device may have a top emission structure.

[0258] <Configuration Example 2 of Light Emitting Device> Cross-sectional views of a top-emission type light-emitting device are shown in Figures 7(A) and (B). The plate 1001 can be a light-opaque substrate. The steps up to the formation of the connection electrodes are performed in the same manner as in the bottom emission type light emitting device. Thereafter, a third interlayer insulating film 1037 is formed to cover the electrode 1022. This insulating film has a flat The third interlayer insulating film 1037 is connected to the second interlayer insulating film 1021. It may be formed using similar materials as well as a variety of other materials.

[0259] The lower electrode 1025W, the lower electrode 1025R, the lower electrode 1025G, and the lower electrode 1 Here, 025B is an anode, but it may be a cathode. In the case of a top emission type light emitting device such as the above, the lower electrode 1025W, the lower electrode It is preferable that the lower electrode 1025R, the lower electrode 1025G, and the lower electrode 1025B are reflective electrodes. It is preferable that the second electrode 1029 has a function of reflecting light and a function of transmitting light. In addition, the second electrode 1029, the lower electrode 1025W, the lower electrode 1025R, and the lower electrode 1 A microcavity structure is applied between the lower electrode 1025B and the lower electrode 1025G to detect light of a specific wavelength. The EL layer 1028 is preferably amplified as described in the first and second embodiments. The device has a structure capable of emitting white light.

[0260] In FIG. 6(A), FIG. 6(B), FIG. 7(A) and FIG. 7(B), the EL layer from which white light is obtained The structure is realized by using multiple light-emitting layers and multiple light-emitting units. However, the configuration for obtaining white light emission is not limited to these.

[0261] In the top emission structure shown in FIG. 7(A) and (B), a colored layer (red colored layer 103 4R, a green colored layer 1034G, and a blue colored layer 1034B) are provided on the sealing substrate 1031. The sealing substrate 1031 is provided with black insulating film 1032 disposed between the pixels. A layer (black matrix) 1035 may be provided. A color layer (red color layer 1034R , green colored layer 1034G, blue colored layer 1034B) and black layer (black matrix The sealing substrate 1031 may be covered with an overcoat layer. A substrate is used.

[0262] In addition, while FIG. 7(A) shows a configuration for full-color display using three colors, red, green, and blue, As shown in B), a full-color display may be performed using four colors: red, green, blue, and white. The full-color display is not limited to the above. For example, a full-color display using four colors, red, green, blue, and yellow, may be used. A full color display may also be performed.

[0263] A light-emitting element according to one embodiment of the present invention uses a fluorescent material as a guest material. Compared to other materials, the spectrum is sharper, so light with high color purity can be obtained. Therefore, by using the light-emitting element in the light-emitting device shown in this embodiment, color reproducibility can be improved. Therefore, a light emitting device with high light emission efficiency can be obtained.

[0264] As described above, a light emitting device using the light emitting elements described in the first and second embodiments can be obtained.

[0265] Note that this embodiment mode can be appropriately combined with other embodiment modes.

[0266] (Embodiment 4) In this embodiment, an electronic device and a display device according to one embodiment of the present invention will be described.

[0267] According to one embodiment of the present invention, a highly reliable electronic device and display having a flat surface and high light emission efficiency can be provided. According to one embodiment of the present invention, a reliable display device having a curved surface and high luminous efficiency can be manufactured. The light-emitting element of one embodiment of the present invention can be used to manufacture highly reliable electronic devices and display devices. For this reason, when the light-emitting element is used in the light-emitting device described in this embodiment, light emission with high efficiency can be obtained. By using this, electronic devices and display devices with high color reproducibility can be obtained.

[0268] Examples of electronic devices include television sets, desktop or notebook PCs, etc. Computers, monitors for computers, digital cameras, digital video cameras Cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, audio playback Examples of such devices include large gaming machines such as pachinko machines.

[0269] A portable information terminal 900 shown in FIGS. 8A and 8B includes a housing 901, a housing 902, a display unit 90 3, and a hinge portion 905.

[0270] The housing 901 and the housing 902 are connected by a hinge portion 905. The mobile information terminal 900 includes: It can be unfolded from the folded state (FIG. 8(A)) to the state shown in FIG. 8(B). This makes it highly portable when you carry it around, and when you use it, the large display area makes it easy to see. Excellent recognition.

[0271] The portable information terminal 900 has a housing 901 and a housing 902 connected by a hinge portion 905. A flexible display unit 903 is provided.

[0272] A light-emitting device manufactured according to one embodiment of the present invention can be used for the display portion 903. This makes it possible to manufacture a highly reliable portable information terminal.

[0273] The display unit 903 is capable of displaying at least one of document information, still images, and moving images. When document information is displayed on the display unit, the portable information terminal 900 is used as an electronic book terminal. It can be used as such.

[0274] When the portable information terminal 900 is unfolded, the display portion 903 is held in a state in which the radius of curvature is large. For example, the radius of curvature is 1 mm or more and 50 mm or less, preferably 5 mm or more and 30 mm or less. The display unit 903 is supported by the housing 901 and the other parts of the display unit 903. Pixels are arranged continuously across the body 902, enabling curved surface display.

[0275] The display unit 903 functions as a touch panel and can be operated by a finger, a stylus, etc. can.

[0276] It is preferable that the display unit 903 is composed of one flexible display. This makes it possible to perform continuous display without interruption between the housing 901 and the housing 902. In addition, a display may be provided in each of the housings 901 and 902. You may do so.

[0277] The hinge portion 905 is a portion that connects the housing 901 and the housing 902 when the mobile information terminal 900 is unfolded. It is preferable to have a locking mechanism to prevent the angle from becoming larger than a predetermined angle. For example, the angle at which the door will lock (will not open any further) must be greater than 90 degrees and less than 180 degrees. Typically, the angle is 90 degrees, 120 degrees, 135 degrees, 150 degrees, or 17 degrees. 5 degrees, etc. This improves the convenience, safety, and Reliability can be improved.

[0278] If the hinge portion 905 has a locking mechanism, the display portion 903 can be opened without applying excessive force. Therefore, it is possible to prevent the display unit 903 from being damaged. It can be achieved.

[0279] The housing 901 and the housing 902 are provided with a power button, an operation button, an external connection port, a speaker, a microphone, and the like. It may have an indentation or the like.

[0280] A wireless communication module is provided in either the housing 901 or the housing 902. Internet, LAN (Local Area Network), Wi-Fi (registered trademark ) and the like.

[0281] A portable information terminal 910 shown in FIG. 8C includes a housing 911, a display unit 912, and an operation button 913. , an external connection port 914, a speaker 915, a microphone 916, a camera 917, etc.

[0282] A light-emitting device manufactured according to one embodiment of the present invention can be used for the display portion 912. This makes it possible to manufacture portable information terminals with a high yield.

[0283] The mobile information terminal 910 has a touch sensor on the display unit 912. All operations, such as inputting characters, can be performed by touching the display 912 with a finger or a stylus. It can be done.

[0284] In addition, the operation button 913 is operated to turn the power on and off, and to display on the display unit 912. For example, you can change the type of image displayed on the main screen from the email composition screen. You can switch to the menu screen.

[0285] In addition, a detection device such as a gyro sensor or an acceleration sensor is provided inside the portable information terminal 910. By providing the above, the orientation of the mobile information terminal 910 (vertical or horizontal) can be determined and the screen of the display unit 912 can be adjusted. The display orientation can be switched automatically. The screen orientation can also be switched by The input is made by touching the display unit 912, by operating the operation button 913, or by inputting voice using the microphone 916. It can also be performed by using force or the like.

[0286] The mobile information terminal 910 is, for example, one or more devices selected from a telephone, a notebook, an information viewing device, etc. Or it has multiple functions. Specifically, it can be used as a smartphone. The information terminal 910 is, for example, a mobile phone, an e-mail, a document viewing and creation, a music playback, a video It can run various applications such as playback, internet communication, and games. do.

[0287] The camera 920 shown in FIG. 8D includes a housing 921, a display unit 922, an operation button 923, and a shutter. The camera 920 also has a detachable lens 926. It is attached.

[0288] The light-emitting device manufactured according to one embodiment of the present invention can be used for the display portion 922. This makes it possible to manufacture a highly reliable camera.

[0289] Here, the camera 920 and the lens 926 can be removed from the housing 921 and replaced. However, the lens 926 and the housing 921 may be integrated together.

[0290] The camera 920 captures still or moving images by pressing the shutter button 924. In addition, the display unit 922 has a function as a touch panel. It is also possible to capture an image by touching the

[0291] The camera 920 can be equipped with a strobe device, viewfinder, etc. Alternatively, these may be incorporated into the housing 921.

[0292] FIG. 9(A) is a schematic diagram showing an example of a cleaning robot.

[0293] The cleaning robot 5100 has a display 5101 arranged on the top surface and multiple The camera 5102, the brush 5103, and the operation button 5104 are also shown. However, the underside of the cleaning robot 5100 is provided with tires, a suction port, etc. The robot 5100 also has an infrared sensor, an ultrasonic sensor, an acceleration sensor, a piezo sensor, It is equipped with various sensors such as a sensor, a light sensor, and a gyro sensor. 100 is equipped with wireless communication means.

[0294] The cleaning robot 5100 moves by itself, detects dirt 5120, and sucks it out from the suction port on its bottom. It can suck up dirt.

[0295] In addition, the cleaning robot 5100 analyzes the image captured by the camera 5102 and detects walls, furniture, or It can detect obstacles such as steps. It can also detect wiring and other obstacles by image analysis. If an object that is likely to get tangled in the brush 5103 is detected, the rotation of the brush 5103 can be stopped. can.

[0296] The display 5101 can display the remaining battery level, the amount of dirt sucked up, etc. The route traveled by the cleaning robot 5100 can be displayed on the display 5101. In addition, the display 5101 may be a touch panel, and the operation buttons 5104 may be a display. It may be provided in the ray 5101.

[0297] The cleaning robot 5100 can communicate with a portable electronic device 5140 such as a smartphone. The images captured by the camera 5102 can be displayed on the portable electronic device 5140. Therefore, the owner of the Cleaning Robot 5100 can check the state of the room even when he / she is away from home. In addition, the display on the display 5101 can be displayed on a mobile electronic device such as a smartphone. You can also check it out at.

[0298] The light-emitting device according to one embodiment of the present invention can be used for the display 5101 .

[0299] The robot 2100 shown in FIG. 9(B) includes a computing device 2110, an illuminance sensor 2101, a microphone 2102, upper camera 2103, speaker 2104, display 2105, The vehicle is equipped with an internal camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0300] The microphone 2102 has a function of detecting the user's voice and environmental sounds. The speaker 2104 has a function of emitting sound. The user can communicate with the computer using the computer 2102 and the speaker 2104. It is possible.

[0301] The display 2105 has a function of displaying various information. It is possible for the user to display desired information on the display 2105. The display 2105 may be equipped with a touch panel. The information terminal may be a terminal that can be used for charging and discharging the battery. and enables data transfer.

[0302] The upper camera 2103 and the lower camera 2106 are used to capture images of the surroundings of the robot 2100. The obstacle sensor 2107 detects the obstacles of the robot 210 using the moving mechanism 2108. When the robot 21 moves forward, it can sense the presence or absence of obstacles in its path. 00 uses an upper camera 2103, a lower camera 2106, and an obstacle sensor 2107. It is possible for the robot to recognize its surrounding environment and move around safely.

[0303] The light-emitting device according to one embodiment of the present invention can be used for the display 2105 .

[0304] FIG. 9C is a diagram showing an example of a goggle-type display. For example, a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, Connection terminal 5006, sensor 5007 (force, displacement, position, speed, acceleration, angular velocity, rotation speed, Distance, light, liquid, magnetism, temperature, chemicals, sound, time, hardness, electric field, current, voltage, power, radiation (including functions to measure radiation, flow rate, humidity, gradient, vibration, odor, or infrared rays), The device includes a microphone 5008, a second display unit 5002, a support unit 5012, an earphone 5013, etc. do.

[0305] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the second display portion 5002. can.

[0306] 10(A) and (B) show a foldable mobile information terminal 5150. The foldable mobile information terminal 5150 includes a housing 5151, a display area 5152, and a bending portion 515. 10(A) shows the portable information terminal 5150 in an unfolded state. FIG. 5B) shows the portable information terminal 5150 in a folded state. The portable information terminal 5150 is large. Although it has a large display area 5152, it can be folded up to be compact and highly portable.

[0307] The display area 5152 can be folded in half by the bend 5153. 3 is composed of an expandable member and multiple support members. When folding the display area, , the expandable member is stretched, and the bent portion 5153 has a curvature of 2 mm or more, preferably 5 mm or more. has a radius.

[0308] The display area 5152 is a touch panel (input / output) equipped with a touch sensor (input device). The light-emitting device according to one embodiment of the present invention can be used in the display region 5152. Cut.

[0309] This embodiment mode can be combined with other embodiment modes as appropriate.

[0310] (Embodiment 5) In this embodiment, an example in which the light-emitting element of one embodiment of the present invention is applied to various lighting devices will be described. The light-emitting element according to one embodiment of the present invention is used to improve the light-emitting efficiency. Thus, a highly reliable lighting device can be manufactured.

[0311] The light-emitting element of one embodiment of the present invention can be fabricated over a flexible substrate to have a curved surface. It is possible to realize electronic devices and lighting devices having a light-emitting region.

[0312] In addition, a light-emitting device using a light-emitting element according to one embodiment of the present invention can be used for automobile lighting. For example, lighting can be installed on the windshield, ceiling, etc.

[0313] FIG. 11 shows an example in which the light-emitting element is used as an indoor lighting device 8501. Since the surface area can be increased, a large-area lighting device can be formed. By using a housing having such a curved light-emitting area, a lighting device 8502 can be formed. The light-emitting element shown in this embodiment mode has a thin film shape, and the design of the housing has a high degree of freedom. Therefore, it is possible to form lighting devices with various elaborate designs. A large lighting device 8503 may be provided on the wall. A touch sensor may be provided in 503 to turn the power on or off.

[0314] In addition, by using light-emitting elements on the surface of the table, it has the function of a table. The lighting device 8504 can be used as a lighting device. This makes it possible to provide a lighting device that also functions as furniture.

[0315] In this manner, a lighting device and an electronic device can be obtained by using the light-emitting device of one embodiment of the present invention. Note that the light-emitting device according to one embodiment of the present invention is not limited to that described in this embodiment. The present invention can be applied to lighting devices and electronic devices in a wide range of fields.

[0316] The structure described in this embodiment may be used in appropriate combination with structures described in other embodiments. There can be. EXAMPLES

[0317] In this example, light-emitting elements 2 to 5 which are light-emitting elements of one embodiment of the present invention and a comparative light-emitting element An example of the fabrication of an optical element 1 is shown in FIG. 1(A) and FIG. The details of the molecular structure are shown in Tables 2 and 3. The formula is shown below. For the structures and abbreviations of other compounds, please refer to the first embodiment. That would be good.

[0318] [ka]

[0319] [Table 2]

[0320] [Table 3]

[0321] <Fabrication of light-emitting element> The method for producing the light-emitting element produced in this example is described below. The light-emitting element 2 uses LiF, a Li compound that is commonly used in The light-emitting element 5 is an embodiment of the present invention, in which an electron injection layer is provided with a tridentate or tetradentate metal-interacting element. The light-emitting element is made of a composite material of an organic compound and a metal, which has a function of emitting light.

[0322] <Preparation of comparative light-emitting element 1> An ITSO film was formed on a glass substrate as an electrode 101 to a thickness of 110 nm. The electrode area of ​​the electrode 101 is 4 mm 2 (2mm x 2mm).

[0323] Next, a hole injection layer 111 made of DBT3P-II and molybdenum oxide ( MoO3) in a weight ratio (DBT3P-II:MoO3) of 1:0.5, The layers were co-evaporated to a thickness of 25 nm.

[0324] Next, a hole transport layer 112 was formed on the hole injection layer 111 by depositing PCBBiF to a thickness of 20 nm. The deposition was carried out as follows.

[0325] Next, on the hole transport layer 112, 2mDBTBPDBq-II and P CBBiF and Ir(dmdppr-dmp)2(dpm) in a weight ratio of (2mDBTBP DBq-II:PCBBiF:Ir(dmdppr-dmp)2(dpm)) is 0.75 The mixture was co-deposited in an amount of 0.25:0.08 and in a thickness of 40 nm. In the light-emitting layer 140, 2mDBTBPDBq-II and PCBBiF are host materials. and Ir(dmdppr-dmp)2(dpm) is the guest material (phosphorescent compound). .

[0326] Next, 2mDBTBPDBq-II was added as the electron transport layer 118(1) on the light-emitting layer 140. was evaporated to a thickness of 20 nm.

[0327] Next, NBPhen was deposited to a thickness of 118(1) as the electron transport layer 118(2). The deposition was carried out so that the thickness became 15 nm.

[0328] On the electron transport layer 118(2), lithium fluoride (LiF) is deposited as an electron injection layer 130. The deposition was carried out so that the thickness was 1 nm.

[0329] Next, on the electron injection layer 130, aluminum (Al) was deposited to a thickness of 20 It was formed so that the thickness was 0 nm.

[0330] Next, without sealing, the device was heat-treated in air at 80°C for 1 hour. Optical element 1 was obtained.

[0331] <Fabrication of Light-Emitting Devices 2 to 5> The light-emitting elements 2 to 5 are the same as the comparative light-emitting element 1 except for the process of forming the electron injection layer 130. It was made using the same process.

[0332] <Fabrication of Light-emitting Device 2> On the electron transport layer 118(2), an electron injection layer 130 was formed by mixing tPy2P and Ag in a weight ratio (t The film was co-evaporated at a ratio of Py2P:Ag of 1:0.3 to a thickness of 5 nm.

[0333] <Fabrication of Light-emitting Device 3> On the electron transport layer 118(2), an electron injection layer 130 was formed by depositing 2Py3Tzn and Cu in a weight ratio. The layers were co-evaporated in a ratio of (2Py3Tzn:Cu) 1:0.3 to a thickness of 5 nm.

[0334] <Fabrication of Light-emitting Device 4> On the electron transport layer 118(2), an electron injection layer 130 was formed by depositing Pm3Tzn and Cu in a weight ratio of ( The layers were co-evaporated at a ratio of Pm3Tzn:Cu of 1:0.3 to a thickness of 5 nm.

[0335] <Fabrication of Light-emitting Device 5> The electron injection layer 130 is formed on the electron transport layer 118(2) by mixing tPy2P and Co in a weight ratio of (t The layer was co-evaporated at a ratio of Py2P:Co of 1:0.2 to a thickness of 5 nm.

[0336] <Characteristics of light-emitting element> Next, the element characteristics of the comparative light-emitting element 1 and the light-emitting elements 2 to 5 prepared above were measured. A color luminance meter (Topcon, BM-5A) was used to measure luminance and CIE chromaticity. The electroluminescence spectrum was measured using a multichannel spectrometer (Hamamatsu Photonics, PMA- 11) was used.

[0337] FIG. 12 shows the current efficiency vs. luminance characteristics of the fabricated comparative light-emitting element 1 and light-emitting elements 2 to 5. The current-voltage characteristics are shown in FIG. 13, and the external quantum efficiency-luminance characteristics are shown in FIG. 14. The measurements of each light-emitting element were carried out at room temperature (an atmosphere maintained at 23°C). 5mA / cm 2 The electroluminescence spectrum when a current was applied at a current density of 1000 s is shown in FIG. The measurements were carried out at room temperature.

[0338] Also, 1000cd / m 2 Comparative light-emitting element 1 and light-emitting element 2 to The device characteristics of 5 are shown in Table 4.

[0339] [Table 4]

[0340] As shown in FIG. 14 and Table 4, the comparative light-emitting element 1 and the light-emitting elements 2 to 5 each have The external quantum efficiency of the present invention was also higher than 25%, which is a high luminous efficiency. The light-emitting elements 2 to 5 use LiF, which is a material commonly used for the electron injection layer. The light-emitting element showed a high efficiency equivalent to that of the comparative light-emitting element 1.

[0341] As shown in FIG. 13 and Table 4, the comparative light-emitting element 1 and the light-emitting elements 2 to 5 have good The light-emitting elements 2 to 5 exhibited excellent current-voltage characteristics. -Voltage characteristics, transition with large work function (4.5 eV or more) like Cu, Ag, and Co Composite materials made of metals and organic compounds that have the ability to interact with the metals at tridentate or tetradentate sites have been It has excellent electron injection properties equivalent to those of LiF, a material commonly used for electron injection layers. It was found that...

[0342] As shown in FIG. 15, the electric field emission of the comparative light-emitting element 1 and the light-emitting elements 2 to 5 is The peak wavelength of the optical spectrum is around 619 nm, and the full width at half maximum is 58 nm. The obtained electroluminescence spectrum showed that the guest material It was found that the emission was from Ir(dmdppr-dmp)2(dpm).

[0343] <Constant current driving test results for light emitting elements> Next, a constant current drive test of the comparative light-emitting element 1 and the light-emitting elements 2 to 5 at 1.0 mA was performed. The experiment was carried out in an air atmosphere. The results are shown in Figure 16. The element 1 and the light-emitting elements 2 to 5 are not sealed. The light-emitting element 2 to the light-emitting element 5 have better reliability than the comparative light-emitting element 1 in the air. Comparative light-emitting element 1 uses a material having a metal with a small work function in the electron injection layer. Metals with small work functions are highly reactive with water, and moisture can penetrate into the light-emitting element. Therefore, when the light-emitting element 1 is driven in an air atmosphere, it is likely to be affected by moisture. On the other hand, the light-emitting element according to one embodiment of the present invention has poor reactivity with water. A metal having a large work function can be used for the electron injection layer. The light-emitting element is designed to be reliable even when operated in an air atmosphere because moisture does not easily penetrate into the light-emitting element. Furthermore, the light-emitting elements 3 to 5 have excellent reliability. This shows that metals with a work function of 4.7 eV or more, such as Cu and Co, By using such a compound, a light emitting element having excellent reliability can be realized. EXAMPLES

[0344] In this example, light-emitting elements 7 to 10 which are light-emitting elements of one embodiment of the present invention and a comparative light-emitting element An example of fabricating a light-emitting element 6 is shown in FIG. 1(A) is a schematic cross-sectional view of the light-emitting element fabricated in this example. The details of the device structure are shown in Tables 5 and 6. The structures of the organic compounds used in this example are shown in Tables 5 and 6. Regarding the structure and abbreviations, the above-mentioned first embodiment and first example may be referred to.

[0345] [Table 5]

[0346] [Table 6]

[0347] <Fabrication of light-emitting element> The method for producing the light-emitting device in this example is described below. The light-emitting element 7 to the light-emitting element 9 are light-emitting elements in which the electrode and the electron transport layer are in contact with each other, and no layer is formed thereon. The optical element 10 is an embodiment of the present invention, in which an electron injection layer is provided with a tridentate or tetradentate metal. The light-emitting element uses a composite material of a functional organic compound and a metal.

[0348] <Preparation of Comparative Light-Emitting Element 6> The comparative light-emitting element 6 was fabricated in the same manner as the comparative light-emitting element 1, except for the step of forming the electron injection layer 130. It was made.

[0349] In the comparative light-emitting element 6, the electron injection layer 130 was not formed, and the electrode 102 was formed on the electron transport layer 118. In other words, the comparative light-emitting element 6 has an electrode 10 and an aluminum layer 11 deposited thereon to a thickness of 200 nm. 2 is in contact with the electron transport layer 118 .

[0350] <Fabrication of Light-emitting Elements 7 to 10> The light-emitting elements 7 to 10 are identical to the comparative light-emitting element 1 except for the step of forming the electron injection layer 130. It was produced using the same process.

[0351] <Preparation of Light-Emitting Element 7> On the electron transport layer 118(2), tPy2P and Au were deposited as the electron injection layer 130 of the light emitting element 7. were co-deposited in a weight ratio (tPy2P:Au) of 1:0.6 to a thickness of 5 nm. .

[0352] <Preparation of Light-Emitting Element 8> On the electron transport layer 118(2), 2Py3Tzn and Ag was added to the mixture in a weight ratio (2Py3Tzn:Ag) of 1:0.5 and a thickness of 5 nm. It was evaporated.

[0353] <Preparation of Light-Emitting Element 9> On the electron transport layer 118(2), tPy2P and Cu were deposited as the electron injection layer 130 of the light emitting element 9. were co-deposited in a weight ratio (tPy2P:Cu) of 1:0.2 to a thickness of 5 nm. .

[0354] <Fabrication of Light-Emitting Element 10> The electron transport layer 118(2) is formed on the electron injection layer 130 of the light emitting element 10 by the addition of 2Py3Tzn and Co in a weight ratio (2Py3Tzn:Co) of 1:0.3 and a thickness of 5 nm. Co-evaporation was performed.

[0355] <Characteristics of light-emitting element> Next, the device characteristics of the comparative light-emitting element 6 and the light-emitting elements 7 to 10 prepared above were measured. The measurements were carried out in the same manner as in Example 1.

[0356] FIG. 17 shows the current efficiency-luminance characteristics of the fabricated comparative light-emitting element 6 and the light-emitting elements 7 to 10. The current-voltage characteristics are shown in FIG. 18, and the external quantum efficiency-luminance characteristics are shown in FIG. The measurements of each light-emitting device were carried out at room temperature (an atmosphere maintained at 23°C). .5mA / cm 2 The electroluminescence spectrum when a current was applied at a current density of 1000 nm is shown in FIG. The measurements were carried out at room temperature.

[0357] Also, 1000cd / m 2 Comparative light-emitting element 6 and light-emitting element 7 to The device characteristics of 10 are shown in Table 7.

[0358] [Table 7]

[0359] As shown in FIG. 19 and Table 7, the light-emitting elements 7 to 10 have higher optical properties than the comparative light-emitting element 6. In particular, the light-emitting elements 9 and 10 exhibited high external quantum efficiency, exceeding 25%. As shown in FIG. 18, the light-emitting elements 7 to 10 exhibited high external quantum efficiency. The light-emitting element 9 showed better current-voltage characteristics than the comparative light-emitting element 6. In particular, the light-emitting element 9 showed excellent current-voltage characteristics. From these results, the light-emitting elements 7 to 10 are comparative light-emitting elements. It can be seen that the electron injection properties are better than those of 6.

[0360] In the comparative light-emitting element 6, the electrode and the electron transport layer are in contact with each other, and in the light-emitting elements 7 to 10, The electron injection layer uses a metal with a higher work function than the aluminum used in the electron injection layer. In terms of the work function of metals, the comparative light-emitting element 6 has a higher work function than the light-emitting elements 7 to 10. However, as described above, the light-emitting elements 7 to The optical element 10 has better electron injection characteristics than the comparative light-emitting element 6. In the light-emitting element according to one embodiment of the present invention, the electron injection layer has a function of interacting with a metal at a tridentate or tetradentate. By using a composite material of an organic compound and a metal having the above structure, the S of the composite material can be used in the electron injection layer. The OMO is formed by injecting electrons into a metal with a work function higher than that of the electrode material. When used in a layer, good electron injection properties can be obtained.

[0361] 20, the electric field of the comparative light-emitting element 6 and the light-emitting elements 7 to 10 is The peak wavelength of the emission spectrum is around 619 nm, and the full width at half maximum is 58 The obtained electroluminescence spectrum showed that the guest material It was found that the emission was from Ir(dmdppr-dmp)2(dpm).

[0362] <Constant current driving test results for light emitting elements> Next, the comparative light-emitting element 6 and the light-emitting elements 7 to 10 were driven at a constant current of 1.0 mA. The test was performed in an air atmosphere, and the results are shown in FIG. The light emitting elements 7 to 10 are not sealed. It was found that the light-emitting element 10 had better reliability than the comparative light-emitting element 6. 19, the electron injection characteristics of the comparative light-emitting element 6 are inferior to those of the light-emitting elements 7 to 10. The carrier balance of the comparative light-emitting element 6 is poor, which has an adverse effect on the reliability. On the other hand, the light-emitting element according to one embodiment of the present invention has good electron injection characteristics. Since the carrier balance in the semiconductor is good, it is possible to realize a highly reliable light-emitting device. This can be done. EXAMPLES

[0363] In this example, light-emitting elements 12 to 15, which are light-emitting elements according to one embodiment of the present invention, and a comparative An example of the fabrication of a comparative light-emitting element 11 is shown in FIG. 1(A). The details of the device structure are shown in Tables 8 and 9. The organic compounds used in this example are The chemical formula of is shown below. The structures and abbreviations of other compounds are as described in the previous Examples and Examples. Please refer to form 1 above.

[0364] [ka]

[0365] [Table 8]

[0366] [Table 9]

[0367] <Fabrication of light-emitting element> The method for fabricating the light-emitting device according to this embodiment is as follows. The light-emitting device 1 uses LiF, a commonly used Li compound, in the layer. The light-emitting elements No. 2 to No. 15 are one embodiment of the present invention, in which an electron-injection layer has a tridentate or tetradentate metal-interacting element. The light-emitting element is a light-emitting element that uses a composite material of an organic compound and a metal having a function of acting.

[0368] <Preparation of Comparative Light-Emitting Element 11> An ITSO film was formed on a glass substrate as an electrode 101 to a thickness of 70 nm. The electrode area of ​​the electrode 101 is 4 mm 2 (2mm x 2mm).

[0369] Next, a hole injection layer 111 made of DBT3P-II and molybdenum oxide ( MoO3) in a weight ratio (DBT3P-II:MoO3) of 1:0.5, The layers were co-evaporated to a thickness of 40 nm.

[0370] Next, a hole transport layer 112 was formed on the hole injection layer 111 by depositing PCCP to a thickness of 20 nm. It was evaporated like this.

[0371] Next, on the hole transport layer 112, 9-[3-(4,6-diphenyl- 1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H -Carbazole (abbreviation: mPCCzPTzn-02), PCCP and GD270 (Jilin O LED Co., Ltd.) and the weight ratio (mPCCzPTzn:PCCP:GD270) is 0.5:0 The layers were co-deposited in a ratio of 0.5:0.1 to a thickness of 40 nm. In 140, mPCCzPTzn and PCCP are the host materials, and GD270 is the gate. The phosphorescent material is a phosphorescent compound.

[0372] Next, mPCCzPTzn-02 was deposited on the light-emitting layer 140 as the electron transport layer 118(1). The deposition was carried out to a thickness of 10 nm.

[0373] Next, NBPhen was deposited to a thickness of 118(1) as the electron transport layer 118(2). The deposition was carried out so that the thickness became 15 nm.

[0374] An electron injection layer 130 was formed on the electron transport layer 118(2) by depositing LiF to a thickness of 1 nm. The vapor was evaporated.

[0375] Next, on the electron injection layer 130, aluminum (Al) was deposited to a thickness of 20 It was formed so that the thickness was 0 nm.

[0376] Next, without sealing, the device was heat-treated in air at 80°C for 1 hour. Optical element 11 was obtained.

[0377] <Fabrication of Light-emitting Elements 12 to 15> The light-emitting elements 12 to 15 are formed in the form of an electron transport layer 118(2) and an electron injection layer 130. The process for producing the comparative light-emitting element 11 was the same as that for producing the comparative light-emitting element 11 except for the above-mentioned steps.

[0378] <Fabrication of Light-Emitting Element 12> On the electron transport layer 118(1), NBPhen was deposited to a thickness of 15 nm as the electron transport layer 118(2). Next, an electron injection layer 130 was deposited on the electron transport layer 118(2). The weight ratio of tPy2P and Ag (tPy2P:Ag) is 1:0.3, and the thickness is 5 nm. The mixture was co-evaporated as shown below.

[0379] <Fabrication of Light-Emitting Element 13> On the electron transport layer 118(1), NBPhen is deposited to a thickness of 10 nm as the electron transport layer 118(2). Next, an electron injection layer 130 was deposited on the electron transport layer 118(2). The weight ratio of NBPhen and Ag (NBPhen:Ag) was 1:0.3, and the thickness was 5 nm. Then, tPy2P and Au were co-deposited on top of it in a weight ratio (tPy2P:Au) of 1:0. .6 and co-evaporated to a thickness of 5 nm.

[0380] <Fabrication of Light-Emitting Element 14> On the electron transport layer 118(1), NBPhen was deposited to a thickness of 15 nm as the electron transport layer 118(2). Next, an electron injection layer 130 was deposited on the electron transport layer 118(2). The weight ratio of 2Py3Tzn and Cu (2Py3Tzn:Cu) is 1:0.3, and the thickness is 5 nm. The mixture was co-evaporated to give a thickness of m.

[0381] <Fabrication of Light-Emitting Element 15> On the electron transport layer 118(1), NBPhen is deposited to a thickness of 10 nm as the electron transport layer 118(2). Next, an electron injection layer 130 was deposited on the electron transport layer 118(2). The weight ratio of NBPhen and Cu (NBPhen:Cu) was 1:0.2 and the thickness was 5 nm. Then, 2Py3Tzn and Co were deposited on top of it in a weight ratio of (2Py3Tzn:Co). The mixture was co-evaporated in a ratio of 1:0.2 to a thickness of 5 nm.

[0382] <Characteristics of light-emitting element> Next, the element characteristics of the comparative light-emitting element 11 and the light-emitting elements 12 to 15 fabricated above were evaluated. The measurement was carried out in the same manner as in Example 1.

[0383] FIG. 1 shows the current efficiency-luminance characteristics of the comparative light-emitting element 11 and the light-emitting elements 12 to 15. 22, the current-voltage characteristics are shown in FIG. 23, and the external quantum efficiency-luminance characteristics are shown in FIG. The measurements of each light-emitting element were carried out at room temperature (an atmosphere maintained at 23°C). at 2.5mA / cm 2 The electroluminescence spectrum when a current was applied at a current density of The measurements were carried out at room temperature.

[0384] Also, 1000cd / m2 The comparative light-emitting element 11 and the light-emitting element 12 are in the vicinity of the The device characteristics of Device 15 are shown in Table 10.

[0385] [Table 10]

[0386] As shown in FIG. 24 and Table 10, the comparative light-emitting element 11 and the light-emitting elements 12 to 15 It was found that the light-emitting elements 12 to 14 had equivalent external quantum efficiency. The internal quantum efficiency was high, exceeding 20%. The comparison light-emitting element 11 and the light-emitting elements 12 to 15 exhibited equivalent current-voltage characteristics. From these results, it can be seen that the light-emitting elements 12 to 15 have an L It is seen that the electron injection property is equivalent to that of the comparative light-emitting element 11 using iF.

[0387] As shown in FIG. 25, the comparative light-emitting element 11 and the light-emitting elements 12 to 15 have the same electric field strength. The peak wavelengths of the field emission spectra are all around 520 nm, and the full width at half maximum is 6 The electroluminescence spectrum obtained showed that the guest material It was found that the emission was from GD270.

[0388] <Evaluation of Reliability of Light-Emitting Device> Next, a constant temperature and humidity storage test was carried out on the comparative light-emitting element 11 and the light-emitting elements 12 to 15. Since each light-emitting element was not sealed, the cathode and EL layer were not exposed to the atmosphere of the test environment. Generally, when moisture gets into a light-emitting element, dark spots (light-emitting This causes non-light-emitting areas inside the light-emitting area and shrinkage (non-light-emitting areas at the edge of the light-emitting area). This adversely affects the reliability of the light-emitting element. It is possible to evaluate the reliability of the child's moisture.

[0389] The comparative light-emitting element 11 and the light-emitting elements 12 to 15 were each subjected to a test under conditions of temperature of 40° C. and humidity of 9 After leaving the device in a thermostatic chamber with a constant temperature of 0%, the light emission state of each light-emitting element was We investigated the following.

[0390] The luminous state was evaluated by estimating the ratio of the luminous area before and after the constant temperature and humidity storage test. The results are shown in Table 11.

[0391] [Table 11]

[0392] In Table 11, the luminous area ratio (%) = luminous area after constant temperature and humidity storage test / luminous area before constant temperature and humidity test From Table 11, when LiF, an alkali metal compound, is used for the electron injection layer, The comparative light-emitting element 11 deteriorated during the storage test and became non-emitting. The light-emitting elements 12 to 15 have a light-emitting area ratio greater than that of the comparative light-emitting element 11. That is, the light-emitting element of one embodiment of the present invention can emit light with a large amount of alkali metal. It has been found that the material has better moisture resistance than light-emitting devices that use a material with a small work function such as this for the electron injection layer. This is because materials with small work functions are highly reactive with water, and moisture inside the light-emitting element On the other hand, the light-emitting element according to one embodiment of the present invention has poor reactivity with water. Since metals with large work functions can be used, moisture is less likely to penetrate into the inside of the light-emitting element. Therefore, a light emitting element having high moisture resistance can be realized.

[0393] As described above, the light-emitting element of one embodiment of the present invention has excellent electron injection properties and therefore requires low driving voltage. In addition, a material with a high work function can be used. Therefore, the light emitting element has excellent moisture resistance. It can be used in appropriate combination with the form. EXAMPLES

[0394] Example 1 In this example, examples of organic compounds that can be used in a light-emitting element according to one embodiment of the present invention will be described. and a synthesis example thereof will be described.

[0395] <4'-[4-(10-phenyl-9-anthryl)phenyl]-2,2':6',2' Synthesis of '-terpyridine (abbreviation: PAtPy) (structural formula (200)) Add 4'-(4-bromophenyl)-2,2':6',2''-tetrafluoroethylene to a 100 mL three-neck flask. - Pyridine 1.0g (2.6mmol), 10-phenyl-9-anthrylboronic acid 0. 86g (2.9mmol), sodium carbonate 0.85g (8.0mmol), toluene 2 The mixture was stirred under reduced pressure. The flask was degassed and then replaced with nitrogen. Add 65 mg (56 μmol) of palladium(0) and 100 The mixture was refluxed at ℃ for 8 hours. After stirring, the reaction mixture was cooled to room temperature, and the precipitated solid was filtered by suction. The chloroform solution of the solid was dissolved in water, saturated sodium bicarbonate, saturated sodium chloride, and then concentrated. Washed with brine and dried over magnesium sulfate. Mixture of chloroform solution and magnesium sulfate The mixture was gravity filtered, and the filtrate was concentrated to obtain a solid. The solid was collected by suction filtration. It was then recrystallized from toluene. The objective product, a pale red powder, was obtained in an amount of 1.2 g and a yield of 81%. -1).

[0396] [ka]

[0397] The resulting pale red powder (1.2 g) was purified by train sublimation. The production was carried out by heating PAtPy at 290°C under the conditions of a pressure of 4.5 Pa and an argon flow rate of 10 mL / min. After sublimation purification, 0.55 g of pale red powder of PAtPy was obtained, with a recovery rate of 47%. Got it.

[0398] The pale red powder obtained above was analyzed by nuclear magnetic resonance spectroscopy ( 1 The results were measured using H-NMR. is shown below.

[0399] 1 H-NMR (CDCl3,300MHz): δ=7.34-7.40(m, 6H), 7 .49-7.79(m, 11H), 7.91(dt, J=1.5Hz, 7.2Hz, 2H ), 8.16(d, J=7.8Hz, 2H), 8.72-8.78(m, 4H), 8.9 3(s, 2H).

[0400] In addition, the pale red powder obtained 1 The H NMR charts are shown in Figures 26(A) and 26(B). FIG. 26(B) is an enlarged view of the range from 7.0 ppm to 9.5 ppm in FIG. 26(A). The measurement results showed that the target substance, PAtPy, was obtained. EXAMPLES

[0401] Example 1 In this example, examples of organic compounds that can be used in a light-emitting element according to one embodiment of the present invention will be described. and a synthesis example thereof will be described.

[0402] <2-[4'-(2,2':6',2''-terpyridin-4'-yl)biphenyl-4 Synthesis of [-yl]benzoxazole (abbreviation: BOxtPy) (structural formula (201)) Add 4'-(4-bromophenyl)-2,2':6',2''-tetrafluoroethylene to a 100 mL three-neck flask. -pyridine 1.0g (2.6mmol), 4-(benzoxazol-2-yl)phenyl 0.68 g (2.9 mmol) of boronic acid, 0.62 g (5.8 mmol) of sodium carbonate ), 20 mL of toluene, 5 mL of ethanol, and 3 mL of water were added. The mixture was stirred under reduced pressure. The mixture was degassed while stirring, and then the atmosphere in the flask was replaced with nitrogen. Add 63 mg (55 μmol) of phenylphosphine palladium (0) and place under a nitrogen stream. The mixture was refluxed at 100° C. for 5 hours. After reflux, the reaction mixture was cooled to room temperature and precipitated. The solid was collected by suction filtration. The chloroform solution of the obtained solid was diluted with water, saturated hydrogen carbonate, and The resulting chloroform solution was washed with sodium chloride and saturated saline, and then dried over magnesium sulfate. The mixture of the solution and magnesium sulfate was gravity filtered, and the filtrate was concentrated to obtain a solid. The product was recrystallized from toluene to give 1.0 g of a pale red powder in a yield of 78%. This synthesis scheme is shown in formula (b-1) below.

[0403] [ka]

[0404] The resulting BOxtPy powder (1.0 g) was purified by train sublimation. The sublimation purification was carried out under the conditions of a pressure of 4.4 Pa and an argon flow rate of 10 mL / min. After sublimation purification, 0.64 g of pale red powder of BOxtPy was recovered. The rate was 63%.

[0405] The pale red powder obtained above was analyzed by nuclear magnetic resonance spectroscopy ( 1 The results were measured using H-NMR. is shown below.

[0406] 1 H-NMR (CDCl3,300MHz): δ=7.32-7.41(m, 4H), 7 .59-7.65(m, 1H), 7.78-7.93(m, 7H), 8.05(d, J= 8.4Hz, 2H), 8.37(d, J=7.8Hz, 2H), 8.70(d, J=7. 8Hz, 2H), 8.75-8.77(m, 2H), 8.81(s, 2H).

[0407] In addition, the pale red powder obtained 1 The H NMR charts are shown in Figures 27(A) and 27(B). FIG. 27(B) is an enlarged view of the range from 7.0 ppm to 9.0 ppm in FIG. 27(A). The measurement results showed that the target substance, BOxtPy, was obtained. EXAMPLES

[0408] Example 1 In this example, examples of organic compounds that can be used in a light-emitting element according to one embodiment of the present invention will be described. and a synthesis example thereof will be described.

[0409] 4'-{4-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl phenyl}-2,2':6',2''-terpyridine (abbreviation: O11tPy) (structure Synthesis of formula (202) Add 4'-(4-bromophenyl)-2,2':6',2''-tetrafluoroethylene to a 100 mL three-neck flask. -pyridine 1.0g (2.6mmol), 4-(5-phenyl-1,3,4-oxadiazide 0.73g (2.7mmol) phenylboronic acid, 0.01g sodium carbonate .71g (6.7mmol), 20mL of toluene, 5mL of ethanol, and 3mL of water were added. The mixture was degassed by stirring under reduced pressure, and the atmosphere in the flask was replaced with nitrogen. , 68 mg (59 μmol) of tetrakis(triphenylphosphine)palladium(0) The mixture was refluxed at 100°C for 9 hours under a nitrogen stream. After stirring, the mixture was The mixture was cooled to room temperature, and the precipitated solid was filtered off with suction. The chloroform solution of the obtained solid was diluted with water, Wash with saturated aqueous sodium bicarbonate solution and saturated saline, then dry with magnesium sulfate. The mixture was gravity filtered, and the filtrate was concentrated to obtain a solid. The obtained solid was dissolved in methanol. After washing with toluene / hexane, the product was recrystallized and the desired white powder was obtained in a yield of 0. The synthesis scheme was shown in formula (c-1) below.

[0410] [ka]

[0411] The obtained O11tPy powder (0.71 g) was purified by train sublimation. The sublimation purification was carried out under the conditions of a pressure of 4.0 Pa and an argon flow rate of 10 mL / min. After sublimation purification, 0.29 g of white powder of O11tPy was recovered. The rate was 41%.

[0412] The white powder obtained above was analyzed by nuclear magnetic resonance spectroscopy ( 1The analysis results were measured by H-NMR. Shown below.

[0413] 1 H-NMR (CDCl3,300MHz): δ=7.35-7.39(m, 2H), 7 .52-7.58(m, 3H), 7.79-7.93(m, 6H), 8.04(d, J= 8.4Hz, 2H), 8.16-8.19(m, 2H), 8.24(d, J=8.4Hz , 2H), 8.69(d, J=7.8Hz, 2H), 8.74-8.76(m, 2H), 8.80(s, 2H).

[0414] In addition, the obtained white powder 1 The H NMR charts are shown in Figures 28(A) and 28(B). 28(B) is an enlarged view of the range from 7.0 ppm to 9.0 ppm in FIG. 28(A). The measurement results showed that the target substance, O11tPy, was obtained. EXAMPLES

[0415] Example 1 In this example, examples of organic compounds that can be used in a light-emitting element according to one embodiment of the present invention will be described. and a synthesis example thereof will be described.

[0416] 9,9'-[5-(2,2':6',2''-terpyridin-4'-yl)-1,3- phenylene]bis(9H-carbazole) (abbreviation: Cz2PtPy) (structural formula (203) Synthesis> 0.9 mL of 4'-bromo-2,2':6',2''-terpyridine was added to a 100 mL three-neck flask. 4g (3.0mmol), 3,5-bis(9H-carbazol-9-yl)phenylboro 1.4g (3.2mmol) of carboxylic acid, 0.86g (6.2mmol) of sodium carbonate, 30 mL of benzene, 5 mL of ethanol, and 3 mL of water were added. The mixture was stirred under reduced pressure. The flask was degassed with 1000 ml of water and the atmosphere in the flask was replaced with nitrogen. The mixture was stirred under a nitrogen atmosphere for 1 hour. The mixture was stirred at 80° C. for 7 hours. After stirring, the aqueous layer of the mixture was extracted with toluene. The organic layer was combined and washed with a saturated aqueous solution of sodium bicarbonate and saturated saline, and then diluted with malondiamine sulfate. The mixture was gravity filtered, and the filtrate was concentrated to give a solid. The solid was washed with methanol and then recrystallized with toluene to obtain the desired white powder. The powder was obtained in an amount of 1.1 g and a yield of 55%. The synthesis scheme is shown in the following formula (d-1).

[0417] [ka]

[0418] The resulting Cz2PtPy powder (0.83 g) was purified by train sublimation. The sublimation purification was carried out under the conditions of a pressure of 3.2 Pa and an argon flow rate of 5.0 mL / min. The PtPy was heated at 290°C. After purification by sublimation, the white powder of Cz2PtPy was 0.71 g, with a recovery rate of 86%.

[0419] The white powder obtained above was analyzed by nuclear magnetic resonance spectroscopy ( 1 The analysis results were measured by H-NMR. Shown below.

[0420] 1 H-NMR (CDCl3,300MHz): δ=7.31-7.37(m, 6H), 7 .47(dt, J=0.9Hz, 7.2Hz, 4H), 7.59(d, J=8.1Hz, 4H), 7.85-7.92(m, 3H), 8.17-8.22(m, 6H), 8.66 -8.69(m, 4H), 8.82(s, 2H).

[0421] In addition, the obtained white powder 1 The H NMR charts are shown in Figures 29(A) and 29(B). 29(B) is an enlarged view of the range from 7.0 ppm to 9.0 ppm in FIG. 29(A). The measurement results showed that the target compound, Cz2PtPy, was obtained. EXAMPLES

[0422] Example 1 In this example, examples of organic compounds that can be used in a light-emitting element according to one embodiment of the present invention will be described. and a synthesis example thereof will be described.

[0423] 2,4,6-Tris(5-phenyl-2-pyrimidin-2-yl)-1,3,5-triazolidine Synthesis of PPm3Tzn (abbreviation: PPm3Tzn) (structural formula (105) 0.80g of 5-phenylpyrimidine-2-carboximidamide in a 50mL two-neck flask (4.0mmol), 2-cyano-5-phenylpyridine 1.4g (7.7mmol), 2 mL of diglyme and 1 mL of 1,2,3,4-tetrahydronaphthalene were added. The mixture was stirred under a nitrogen stream at 180° C. for 29 hours and at 200° C. for 100 hours. The mixture was cooled to room temperature and washed with ethyl acetate to give a brown powder, yielding 0.82 g. The synthesis scheme is shown in the following formula (e-1). 1 H-NMR showed that the proton ratio was PPm3Tzn:5-phenylpyrimidinyl The ratio of the target substance to the raw material was 1:1.7. The brown powder was a mixture of the target substance and the raw material. In addition, the signal derived from 2-cyano-5-phenylpyridine was not observed. was not measured.

[0424] [ka]

[0425] The resulting brown powder (0.79 g) was purified by train sublimation. The preparation was carried out at 310°C under conditions of a pressure of 3.7 Pa and an argon flow rate of 15 mL / min. After purification by sublimation, 2,4,6-tris(5-phenyl-2-pyrimidin-2-yl)-1 0.19g of light brown powder of 3,5-triazine was obtained after purification by sublimation. 1 H-NMR was measured. The signal derived from 5-phenylpyrimidine-2-carboximidamide was Therefore, it was found that the target product can be easily purified by sublimation purification.

[0426] The light brown powder obtained above was analyzed by nuclear magnetic resonance spectroscopy ( 1 The results were measured using H-NMR. is shown below.

[0427] 1 H-NMR (CDCl3,300MHz): δ=7.52-7.63(m, 9H), 7 .73(dd, J=1.5Hz, 7.8Hz, 6H), 9.35(s, 6H).

[0428] In addition, the obtained light brown powder 1 The H NMR charts are shown in Figures 30(A) and 30(B). FIG. 30(B) is an enlarged view of the range from 7.0 ppm to 9.5 ppm in FIG. 30(A). The measurement results showed that the target substance, PPm3Tzn, was obtained. EXAMPLES

[0429] As a light-emitting element of one embodiment of the present invention, light-emitting elements 16 to 17, which are examples of a tandem element described later, are The following describes examples of fabricating the optical element 21, the comparative light-emitting element 33, and the comparative light-emitting element 34. A schematic cross-sectional view of the light-emitting device is shown in FIG. 31, and details of the device structure are shown in Tables 12 to 14. The chemical formulas of the organic compounds used in this example are shown below. Regarding the abbreviations, the above examples and the first embodiment may be referred to. The light-emitting element 21 has a plurality of EL layers connected in series between a pair of electrodes via a charge generating layer. In a tandem device, a charge generation layer (charge generation layer in FIG. 31) is placed between the EL layers. The electron injection layer (electron injection layer 114 in FIG. 31) is in contact with the electron generation layer 115. A light-emitting device using a composite material of an organic compound and a metal that has the function of interacting with a metal at a site Here is an example.

[0430] [ka]

[0431] [Table 12]

[0432] [Table 13]

[0433] [Table 14]

[0434] <Fabrication of light-emitting element 16> An ITSO film was formed on a glass substrate as an electrode 101 to a thickness of 110 nm. The electrode area is 4 mm 2 (2mm x 2mm).

[0435] Next, DBT3P-II and MoO3 were laminated on the electrode 101 as the hole injection layer 111. The ratio of the amount of DBT3P-II to MoO3 was 1:0.5, and the thickness was 25 nm. The mixture was co-evaporated so as to obtain a

[0436] Next, a hole transport layer 112 was formed on the hole injection layer 111 by depositing PCBBiF to a thickness of 20 nm. The deposition was carried out as follows.

[0437] Next, 2mDBTBPDBq-II and PC BBiF and Ir(dmdppr-dmp)2(dpm) were mixed in a weight ratio of (2mDBTBPDBq -II:PCBBiF:Ir(dmdppr-dmp)2(dpm)) is 0.75:0. The mixture was co-deposited in a ratio of 25:0.08 to a thickness of 40 nm. In layer 170, 2mDBTBPDBq-II and PCBBiF are host materials; Ir(dmdppr-dmp)2(dpm) is the guest material (phosphorescent compound).

[0438] Next, 2mDBTBPDBq-II was added as the electron transport layer 113(1) on the light emitting layer 170. was evaporated to a thickness of 10 nm. Then, NBP was evaporated as the electron transport layer 113(2). Hen was evaporated to a thickness of 15 nm.

[0439] On the electron transport layer 113(2), an electron injection layer 114 was formed by dissolving 2,2'-(pyridine-2,6 -diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn) 2Py) and Cu in a weight ratio of 1:0.2 (2,6(P-Bqn)2Py:Cu) and a thickness of The film was co-evaporated to a thickness of 5 nm.

[0440] Next, a charge generation layer 115 was formed on the electron injection layer 114 by depositing DBT3P-II and MoO3. The weight ratio (DBT3P-II:MoO3) was 1:0.5, and the thickness was 80 The deposition was carried out by co-evaporation so as to give a thickness of 1 nm.

[0441] Next, a hole transport layer 119 made of PCBBiF was deposited on the charge generation layer 115 to a thickness of 20 nm. The deposition was carried out as follows.

[0442] Next, on the hole transport layer 119, 2mDBTBPDBq-II and P CBBiF and Ir(dmdppr-dmp)2(dpm) in a weight ratio of (2mDBTBP DBq-II:PCBBiF:Ir(dmdppr-dmp)2(dpm)) is 0.75 They were co-evaporated to a thickness of 40 nm so that the ratio of the layers became 0.25:0.08.

[0443] Next, 2mDBTBPDBq-II was added as the electron transport layer 118(1) on the light-emitting layer 140. was evaporated to a thickness of 25 nm. As the layer 118(2), NBPhen was evaporated to a thickness of 10 nm.

[0444] On the electron transport layer 118(2), an electron injection layer 130 was formed by depositing NBPhen and Cu in a weight ratio of ( NBPhen:Cu) was co-evaporated at 1:0.2 to a thickness of 5 nm.

[0445] Next, on the electron injection layer 130, an electrode 102 made of Al was formed to a thickness of 200 nm. was evaporated.

[0446] Next, in a glove box with a nitrogen atmosphere, a glass substrate for sealing is The EL sealant is used to fix the organic material to the glass substrate, forming a light-emitting element 1. Specifically, a sealant was applied around the organic material formed on the glass substrate, The glass substrate and a sealing glass substrate are attached to each other, and ultraviolet light with a wavelength of 365 nm is applied. 6J / cm 2 The light-emitting element 16 was obtained by the above steps. Ta.

[0447] <Fabrication of Light-emitting Elements 17 to 21, Comparative Light-emitting Elements 33, and Comparative Light-emitting Elements 34> The light-emitting elements 17 to 21, the comparative light-emitting element 33, and the comparative light-emitting element 34 are The light-emitting device was fabricated in the same manner as in Light-emitting Device 16. The details of the device structure are shown in Tables 12 to 14. Therefore, details of the fabrication method will be omitted.

[0448] <Measurement of each light-emitting element> The light-emitting elements 16 to 21, the comparative light-emitting element 33, and the comparative light-emitting element 34 fabricated above The device characteristics were measured. The luminance and CIE chromaticity were measured using a colorimeter (Topcon, BM A multichannel spectrometer (Hamamatsu Photonics Co., Ltd.) was used to measure the electroluminescence spectrum. A ferromagnetic material was used (PMA-11, manufactured by Epson Corporation).

[0449] Current of the fabricated light-emitting elements 16 to 21, the comparative light-emitting element 33, and the comparative light-emitting element 34 The efficiency-luminance characteristics are shown in Fig. 32, the current-voltage characteristics in Fig. 33, and the power efficiency-luminance characteristics in Fig. 34. The external quantum efficiency vs. luminance characteristics are shown in FIG. 35. The experiment was carried out in an atmosphere maintained at 3°C. In addition, each light-emitting element was supplied with 2.5 mA / cm 2 At a current density of The electroluminescence spectrum when a current was applied is shown in Figure 36. The measurement was carried out at room temperature.

[0450] Also, 1000cd / m 2Light-emitting elements 16 to 21 and comparative light-emitting element Table 15 shows the element characteristics of the light-emitting element 33 and the comparative light-emitting element 34.

[0451] [Table 15]

[0452] As shown in FIG. 36, the light-emitting elements 16 to 21, the comparative light-emitting element 33, and the comparative light-emitting element The peak wavelengths of the electroluminescence spectra of the elements 34 are all around 620 nm. Light-emitting elements 16 to 21, comparative light-emitting element 33, and comparative light-emitting element 34 are each a light-emitting element. The light emission originates from Ir(dmdppr-dmp)2(dpm), which is a guest material in It was found to show.

[0453] In addition, as shown in FIG. 35 and Table 15, the light-emitting elements 16 to 21 all have The external quantum efficiency exceeded 50%, which was as high as that of comparative light-emitting device 33. In addition, as shown in Figs. 32 and 34, high current efficiency and high power efficiency were observed. The light-emitting element 34 has a low external quantum efficiency of 27.2%, and is not sufficient for use as a tandem element. From these results, it was found that the light-emitting elements 16 to 21 had a charge between the EL layers. Comparison using Li2O, a commonly used Li compound, for the electron injection layer in contact with the generation layer It is seen that the light emitting element has the same electron injection property as the light emitting element 33.

[0454] As shown in FIG. 33 and Table 15, the light-emitting elements 16 to 21 are comparative light-emitting elements. The driving voltage was lower than that of the light-emitting element 33 and the comparative light-emitting element 34, and the light-emitting element 33 exhibited good current-voltage characteristics. Comparative light-emitting element 34 has a very high driving voltage and a problem with electron injection from the charge generation layer. From these results, it was found that the light-emitting elements 16 to 21 have a high current density between the EL layers. The comparison was performed using Li2O, a Li compound commonly used for the electron injection layer in contact with the charge generation layer. It can be seen that the electron injection property is good from the comparative light emitting device 33. Composites of organic compounds and metals with the ability to interact with metals have been used to produce electroluminescence in tandem devices. Even when used as an electron injection layer in contact with a charge generating layer between layers, it shows good driving voltage characteristics. I found out.

[0455] <Constant current driving test results for light emitting elements> Next, the light-emitting element 18, the light-emitting element 19, the comparative light-emitting element 33, and the comparative light-emitting element 34 are compared. A constant current drive test was performed at room temperature in 100 mA. The results are shown in Figure 52. As such, the light-emitting elements 18 and 19 are superior to the comparative light-emitting elements 33 and 34 in terms of From these results, it was found that the light-emitting element 18 and the light-emitting element 1 have good reliability. 9 is a Li compound that is commonly used in the electron injection layer in contact with the charge generation layer, Li2O. Comparative light-emitting element 33 and comparative light-emitting element 34 not having an electron injection layer in contact with the charge generation layer It can be seen that it has better reliability. Therefore, it interacts with metals in a tridentate or tetradentate manner. The composite material of organic compound and metal with the function of distributing the charge between the electroluminescent layers in the tandem device By using it as an electron injection layer in contact with the generation layer, a light-emitting device with excellent reliability can be realized. It is possible.

[0456] As described above, the light-emitting element of one embodiment of the present invention has excellent electron injection properties and therefore requires low driving voltage. In addition, a material with a high work function can be used. Therefore, the light emitting device has excellent moisture resistance and reliability. It can also be used in appropriate combination with the embodiment modes. EXAMPLES

[0457] As light-emitting elements according to embodiments of the present invention, examples of fabrication of light-emitting elements 22 to 25 are described below. A schematic cross-sectional view of the light-emitting device fabricated in the example is shown in FIG. 1, and details of the device structure are shown in Table 16. For the structures and abbreviations of other compounds, please refer to the previous examples and embodiment 1. The light-emitting elements 22 to 25 have a function of interacting with a metal at a tridentate or tetradentate. I, a metal belonging to Group 13, is used as a composite material of an organic compound and a metal having the above structure. It is a light-emitting element that uses n. [Table 16]

[0458] <Fabrication of light-emitting element 22> The light-emitting element 22 was fabricated in the same manner as the comparative light-emitting element 1, except for the step of forming the electron injection layer 130. Made.

[0459] The electron injection layer 130 of the light emitting element 22 is formed by depositing tPy2P and In on the electron transport layer 118(2). were co-deposited at a weight ratio (tPy2P:In) of 1:0.4 to a thickness of 5 nm.

[0460] <Fabrication of light-emitting element 23> The light-emitting element 23 is the same as the comparative example except for the steps of forming the electron transport layer 118(2) and the electron injection layer 130. The light-emitting element was fabricated in the same manner as in the light-emitting element 1.

[0461] As the electron transport layer 118(2) of the light emitting element 23, NBPh was deposited on the electron transport layer 118(1). en was evaporated to a film thickness of 10 nm.

[0462] Next, NBPhen and Ag were deposited on the electron transport layer 118(2) as the electron injection layer 130(1). were co-deposited at a weight ratio (NBPhen:Ag) of 1:0.3 to a thickness of 5 nm. Next, as the electron injection layer 130(2), 2Py3Tzn was deposited on the electron injection layer 130(1). and In were mixed together in a weight ratio (2Py3Tzn:In) of 1:0.6 and the thickness was 5 nm. It was evaporated.

[0463] <Fabrication of light-emitting element 24 and light-emitting element 25> The light-emitting elements 24 and 25 are the same as the light-emitting elements 20 except for the step of forming the electron injection layer 130(2). It was prepared using the same process as in 23.

[0464] <Fabrication of Light-Emitting Element 24> As the electron injection layer 130(2) of the light emitting element 24, 2,6 (P -Bqn)2Py and In are mixed in a weight ratio of (2,6(P-Bqn)2Py:In) of 1:0.3 and The layers were co-evaporated to a thickness of 5 nm.

[0465] <Fabrication of Light-Emitting Element 25> The electron injection layer 130(2) of the light emitting element 25 is formed by depositing 2,6(N P-PPm)2Py and In were mixed in a weight ratio of 1:0 (2,6(NP-PPm)2Py:In). 3 and a thickness of 5 nm.

[0466] The light-emitting elements 22 to 25 were sealed after the cathodes were formed in the same manner as the comparative light-emitting element 1. Without carrying out the above steps, the sample was heat-treated in air at 80°C for 1 hour.

[0467] <Measurement of each light-emitting element> The device characteristics of the fabricated light-emitting elements 22 to 25 were measured. Luminance and CIE color The intensity was measured using a color luminance meter (Topcon, BM-5A), and the electroluminescence spectrum was measured. A multichannel spectrometer (PMA-11, manufactured by Hamamatsu Photonics) was used for the measurement.

[0468] FIG. 37 shows the current efficiency-luminance characteristics of the fabricated light-emitting elements 22 to 25, and FIG. The power efficiency vs. luminance characteristics are shown in Fig. 38, the power efficiency vs. luminance characteristics in Fig. 39, and the external quantum efficiency vs. luminance characteristics in Fig. 40. The measurements of each light-emitting element were carried out at room temperature (an atmosphere maintained at 23°C). 2.5mA / cm for each light emitting element 2 The electroluminescence spectrum when a current is applied at a current density of The measurement was carried out at room temperature.

[0469] Also, 1000cd / m 2 The element characteristics of the light emitting elements 22 to 25 in the vicinity Shown in Table 17.

[0470] [Table 17]

[0471] As shown in FIG. 41, the peak waves of the electroluminescence spectra of the light-emitting elements 22 to 25 The lengths of the light-emitting elements 22 to 25 are all around 615 nm. Luminescence originating from the guest material Ir(dmdppr-dmp)2(dpm) It was found to show the following.

[0472] As shown in FIG. 40 and Table 17, the light-emitting elements 22 to 25 are all externally The quantum efficiency exceeded 25%, demonstrating extremely high luminous efficiency. As shown in Figures 37 and 39, , high current efficiency, and high power efficiency. Therefore, it is believed that the cations interact with metals in a tridentate or tetradentate manner. It has been found that In is suitable as a metal for use in composite materials of functional organic compounds and metals. It was.

[0473] In addition, as shown in FIG. 38, the light-emitting elements 22 to 25 exhibit excellent current-voltage characteristics. Therefore, the complex of the metal and the organic compound that has the function of interacting with the metal at the tridentate or tetradentate position is It was found that In is a suitable metal for use in the alloy.

[0474] As described above, the light-emitting element of one embodiment of the present invention has excellent electron injection properties and therefore requires low driving voltage. In addition, a material with a high work function can be used. Therefore, the light emitting element has excellent moisture resistance. It can be used in appropriate combination with the form. EXAMPLES

[0475] A manufacturing example of light-emitting elements 26 to 28, which are examples of light-emitting elements of one embodiment of the present invention, will be described. A schematic cross-sectional view of the light-emitting device fabricated in this example is shown in FIG. 1, and details of the device structure are shown in Table 18. The chemical formulas of the organic compounds used in this example are shown below. Regarding the structure and abbreviation, the above examples and the first embodiment may be referred to. The light-emitting elements 6 to 28 are made of an organic compound having a function of interacting with a metal at a tridentate or tetradentate position and a metal. The organic compounds used in the composite materials of the group are those having a triazine skeleton or a bipyridine skeleton. This is an example of a light-emitting element using an organic compound. A composite material of an organic compound having a function of interacting with a metal and a metal is used for the electron injection layer 130. is.

[0476] [ka]

[0477] [Table 18]

[0478] <Fabrication of Light-emitting Elements 26 to 28> The light-emitting elements 26 to 28 are the same as the comparative light-emitting element 1 except for the process of forming the electron injection layer 130. It was produced by the same process.

[0479] As the electron injection layer 130 of the light emitting element 26, PPm3Tzn and Co-evaporate Cu to a weight ratio (PPm3Tzn:Cu) of 1:0.2 and a thickness of 5 nm. PPm3Tzn is an example of an organic compound that has a triazine skeleton. PPm3Tzn can also be said to be an organic compound having a pyrimidine skeleton.

[0480] As the electron injection layer 130 of the light emitting element 27, a 2,2′-(2, 2'-bipyridine-6,6'-diyl)bis(4-phenylbenzo[h]quinazoline)( Abbreviation: 6,6'(P-Bqn)2BPy) and Ag in a weight ratio of (6,6'(P-Bqn)2B The Py:Ag) was co-deposited at a ratio of 1:0.3 to a thickness of 5 nm. P-Bqn)2BPy is an example of an organic compound with a bipyridine skeleton. '(P-Bqn)2BPy can also be said to be an organic compound having a quinazoline skeleton.

[0481] As the electron injection layer 130 of the light emitting element 28, 6,6' (PB qn)2BPy) and Cu in a weight ratio (6,6'(P-Bqn)2BPy:Cu) of 1:0. 3 and a thickness of 5 nm.

[0482] The light-emitting elements 26 to 28 were sealed after the cathodes were formed in the same manner as the comparative light-emitting element 1. Without carrying out the above steps, the sample was heat-treated in air at 80°C for 1 hour.

[0483] <Measurement of each light-emitting element> The device characteristics of the fabricated light-emitting elements 26 to 28 were measured. Luminance and CIE color The intensity was measured using a color luminance meter (Topcon, BM-5A), and the electroluminescence spectrum was measured. A multichannel spectrometer (PMA-11, manufactured by Hamamatsu Photonics) was used for the measurement.

[0484] The current efficiency-luminance characteristics of the fabricated light-emitting elements 26 to 28 are shown in FIG. The power efficiency vs. luminance characteristics are shown in Figure 43, the power efficiency vs. luminance characteristics in Figure 44, and the external quantum efficiency vs. luminance characteristics in Figure 45. The measurements of each light-emitting element were carried out at room temperature (an atmosphere maintained at 23°C). 2.5mA / cm for each light emitting element 2 The electroluminescence spectrum when a current is applied at a current density of The measurements were carried out at room temperature.

[0485] Also, 1000cd / m 2 The element characteristics of the light emitting elements 26 to 28 in the vicinity Shown in Table 19.

[0486] [Table 19]

[0487] As shown in FIG. 46, the peak waves of the electroluminescence spectra of the light-emitting elements 26 to 28 The lengths of the light emitting elements 26 to 28 are all around 618 nm. Luminescence originating from the guest material Ir(dmdppr-dmp)2(dpm) It was found to show the following.

[0488] As shown in FIG. 45 and Table 19, the light emitting elements 26 to 28 are all externally The quantum efficiency exceeded 29%, demonstrating extremely high luminous efficiency. As shown in Figures 42 and 44, , high current efficiency, and high power efficiency. Therefore, it is believed that the cations interact with metals in a tridentate or tetradentate manner. As an organic compound used in composite materials of functional organic compounds and metals, or pyrimidine skeleton) or bipyridine skeleton (or quinazoline skeleton) The mixture was found to be suitable.

[0489] In addition, as shown in FIG. 43, the light-emitting elements 26 to 28 exhibit excellent current-voltage characteristics. Therefore, the complex of the metal and the organic compound that has the function of interacting with the metal at the tridentate or tetradentate position is The organic compounds used in the composite materials are those with a triazine skeleton (or pyrimidine skeleton) or bipyridinium. It has been found that organic compounds having a lysine skeleton (or a quinazoline skeleton) are suitable.

[0490] As described above, the light-emitting element of one embodiment of the present invention has excellent electron injection properties and therefore requires low driving voltage. In addition, a material with a high work function can be used. Therefore, the light emitting element has excellent moisture resistance. It can be used in appropriate combination with the form. EXAMPLES

[0491] Fabrication examples of light-emitting elements 29 to 32, which are examples of light-emitting elements of embodiments of the present invention, are described below. A schematic cross-sectional view of the light-emitting device fabricated in this example is shown in FIG. 1, and details of the device structure are shown in Table 20. The chemical formulas of the organic compounds used in this example are shown below. Regarding the structure and abbreviation, the above examples and the first embodiment may be referred to. The light-emitting elements 9 to 32 are made of an organic compound having a function of interacting with a metal at a tridentate or tetradentate position and a metal. As an organic compound for use in the composite material of the group, a light-emitting organic compound having a pyridine skeleton is used. In this embodiment, the function of interacting with a metal at a tridentate or tetradentate is The composite material of an organic compound and a metal having the above formula is used for the electron injection layer 130.

[0492] [Table 20]

[0493] <Fabrication of Light-emitting Elements 29 to 32> The light-emitting elements 29 to 32 are the same as the comparative light-emitting element 1 except for the process of forming the electron injection layer 130. It was produced by the same process.

[0494] As the electron injection layer 130 of the light emitting element 29, 2,6 (P-Bq n) 2Py and Ag are mixed in a weight ratio (2,6(P-Bqn)2Py:Ag) of 1:0.3 and the thickness The deposition was carried out so that the thickness was 5 nm. Note that 2,6(P-Bqn)2Py has a pyridine skeleton. 2,6(P-Bqn)2Py is an example of an organic compound having a quinazoline skeleton. It can also be said that it is an organic compound having the above structure.

[0495] The electron injection layer 130 of the light emitting device 30 is formed by depositing 2,6 (P-Bq n) 2Py and Cu are mixed in a weight ratio (2,6(P-Bqn)2Py:Cu) of 1:0.2 and the thickness The deposition was carried out to a thickness of 5 nm.

[0496] As the electron injection layer 130 of the light emitting element 31, 2,6'(NP- PPm)2Py and Ag in a weight ratio (2,6'(NP-PPm)2Py:Ag) of 1:0.3 The thickness of the film was 5 nm. This is an example of an organic compound with a lysine skeleton. 2,6'(NP-PPm)2Py is also It can also be said to be an organic compound having a pyrimidine skeleton.

[0497] The light-emitting elements 29 to 32 were sealed after the cathode was formed in the same manner as the comparative light-emitting element 1. Without carrying out the above steps, the sample was heat-treated in air at 80°C for 1 hour.

[0498] <Measurement of each light-emitting element> The device characteristics of the fabricated light-emitting elements 29 to 32 were measured. Luminance and CIE color The intensity was measured using a color luminance meter (Topcon, BM-5A), and the electroluminescence spectrum was measured. A multichannel spectrometer (PMA-11, manufactured by Hamamatsu Photonics) was used for the measurement.

[0499] FIG. 47 shows the current efficiency-luminance characteristics of the fabricated light-emitting elements 29 to 32, and FIG. The power efficiency vs. luminance characteristics are shown in Figure 48, the power efficiency vs. luminance characteristics in Figure 49, and the external quantum efficiency vs. luminance characteristics in Figure 50. The measurements of each light-emitting element were carried out at room temperature (an atmosphere maintained at 23°C). 2.5mA / cm for each light emitting element 2 The electroluminescence spectrum when a current is applied at a current density of The measurements were carried out at room temperature.

[0500] Also, 1000cd / m 2 The element characteristics of the light-emitting elements 29 to 32 in the vicinity Shown in Table 21.

[0501] [Table 21]

[0502] As shown in FIG. 51, the peak waves of the electroluminescence spectra of the light-emitting elements 29 to 32 The lengths of the light-emitting elements 29 to 32 are all around 618 nm. Luminescence originating from the guest material Ir(dmdppr-dmp)2(dpm) It was found to show the following.

[0503] As shown in FIG. 50 and Table 21, the light-emitting elements 29 to 32 are all externally The quantum efficiency exceeded 28%, demonstrating extremely high luminous efficiency. As shown in Figures 47 and 49, , high current efficiency, and high power efficiency. Therefore, it is believed that the cations interact with metals in a tridentate or tetradentate manner. As organic compounds used in composite materials of functional organic compounds and metals, It has been found that organic compounds having a pyrimidine skeleton or a quinazoline skeleton are suitable. .

[0504] As shown in FIG. 48, the light-emitting elements 29 to 32 exhibit excellent current-voltage characteristics. Therefore, the complex of the metal and the organic compound that has the function of interacting with the metal at the tridentate or tetradentate position is The organic compounds used in the composite materials are those with a triazine skeleton (or pyrimidine skeleton) or bipyridinium. It has been found that organic compounds having a lysine skeleton (or a quinazoline skeleton) are suitable.

[0505] As described above, the light-emitting element of one embodiment of the present invention has excellent electron injection properties and therefore requires low driving voltage. In addition, a material with a high work function can be used. Therefore, the light emitting element has excellent moisture resistance. It can be used in appropriate combination with the form. [Explanation of symbols]

[0506] 100: EL layer, 101: electrode, 101a: conductive layer, 101b: conductive layer, 102: electrode, 103: Electrode, 103a: Conductive layer, 103b: Conductive layer, 104: Electrode, 104a: Conductive layer , 104b: conductive layer, 106: light-emitting unit, 108: light-emitting unit, 110: EL layer, 111: hole injection layer, 112: hole transport layer, 113: electron transport layer, 115: charge generation layer, 116: hole injection layer, 117: hole transport layer, 118: electron transport layer, 119: electron injection layer, 127: buffer layer, 129: charge generation layer, 130: electron injection layer, 131: compound, 13 2: metal, 133: compound, 140: light-emitting layer, 145: partition wall, 150: light-emitting element, 152 : Light emitting element, 154: Light emitting element, 170: Light emitting layer, 200: Substrate, 220: Substrate, 222 B: region, 222G: region, 222R: region, 223: light-shielding layer, 224B: optical element, 2 24G: optical element, 224R: optical element, 250a: light emitting element, 250b: light emitting element, 6 01: source side driving circuit, 602: pixel section, 603: gate side driving circuit, 604: sealing substrate plate, 605: sealing material, 607: space, 608: wiring, 610: element substrate, 611: switch switching TFT, 612: current control TFT, 613: electrode, 614: insulator, 616 :EL layer, 617: electrode, 618: light emitting element, 623: n-channel TFT, 624: p Channel type TFT, 900: portable information terminal, 901: housing, 902: housing, 903: display 905: hinge section, 910: mobile information terminal, 911: housing, 912: display section, 913 : Operation buttons, 914: External connection port, 915: Speaker, 916: Microphone, 917: Camera, 920: camera, 921: housing, 922: display unit, 923: operation button, 924 : shutter button, 926: lens, 1001: substrate, 1002: underlying insulating film, 100 3: gate insulating film, 1006: gate electrode, 1007: gate electrode, 1008: gate electrode pole, 1020: interlayer insulating film, 1021: interlayer insulating film, 1022: electrode, 1024B: electrode , 1024G: Electrode, 1024R: Electrode, 1024W: Electrode, 1025B: Lower electrode, 1 025G: lower electrode, 1025R: lower electrode, 1025W: lower electrode, 1026: partition, 1028: EL layer, 1029: electrode, 1031: sealing substrate, 1032: sealing material, 103 3: Base material, 1034B: Colored layer, 1034G: Colored layer, 1034R: Colored layer, 1036: Overcoat layer, 1037: interlayer insulating film, 1040: pixel section, 1041: driving circuit section, 1042: Peripheral part, 2100: Robot, 2101: Illuminance sensor, 2102: Microf 2103: upper camera, 2104: speaker, 2105: display, 2106 : Lower camera, 2107: Obstacle sensor, 2108: Moving mechanism, 2110: Calculation device, 5 000: Housing, 5001: Display unit, 5002: Display unit, 5003: Speaker, 5004: LED lamp, 5005: Operation key, 5006: Connection terminal, 5007: Sensor, 5008 : Microphone, 5012: Support, 5013: Earphone, 5100: Cleaning robot, 5101: Display, 5102: Camera, 5103: Brush, 5104: Operation button ,5120: Garbage, 5140: Portable electronic device, 5150: Portable information terminal, 5151: Housing , 5152: display area, 5153: bending part, 8501: lighting device, 8502: lighting device, 8503: Lighting equipment, 8504: Lighting equipment

Claims

1. A first light-emitting unit and a second light-emitting unit are disposed between an anode and a cathode, a first layer between the first light-emitting unit and the second light-emitting unit; the first layer comprises a first organic compound and a metal; The metal belongs to any one of Groups 3 to 13 in the periodic table, the first organic compound has a substituted or unsubstituted heteroaromatic ring having 1 to 30 carbon atoms, the heteroaromatic ring contains nitrogen; the first organic compound has a function of interacting with the metal at a tridentate or tetradentate site on the nitrogen; a sum of the number of electrons of the first organic compound and the number of electrons of the metal is an odd number.

2. In claim 1, a second layer between the cathode and the first layer; The second layer includes a second organic compound having an electron-deficient heteroaromatic ring.

3. In claim 1 or 2, The light-emitting device has a first layer free of alkali metals and alkaline earth metals.

4. A light emitting element according to any one of claims 1 to 3, At least one of a color filter or a transistor; A light emitting device having the above structure.

5. A light emitting device according to claim 4; At least one of a housing or a display unit; An electronic device having the

6. A light emitting element according to any one of claims 1 to 3, A lighting device having a housing.

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