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

Abstract

Provided is a novel light-emitting device having superior convenience, usability, and reliability. This light-emitting device has a first electrode, a second electrode, a unit, and a first layer, wherein the second electrode is provided with a region overlapping the first electrode, and the unit is provided with a region sandwiched between the first electrode and the second electrode and is provided with a second layer and a third layer. The second layer is provided with a region that sandwiches the third layer between the region and the first electrode, and the second layer includes a luminous material. The first layer is provided with a region sandwiched between the third layer and the first electrode. The first layer includes a material that has an acceptor property, and a first material, and the first layer is provided with a first region and a second region. The first region is provided with a region sandwiched between the second region and the first electrode, the first region includes a material having an acceptor property of a first concentration, and the second region includes a material having an acceptor property of a second concentration. The second concentration is greater than zero and less than the first concentration.

Description

[Technical field]

[0001] One embodiment of the present invention relates to a light-emitting device, a light-emitting apparatus, an electronic device, or a lighting apparatus.

[0002] Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, a manufacture, or a composition of matter. Therefore, more specifically, examples of the technical field of one embodiment of the present invention disclosed in this specification include a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, a driving method thereof, or a manufacturing method thereof. [Background technology]

[0003] Light-emitting devices (organic EL elements) that utilize electroluminescence (EL) using organic compounds are becoming more and more practical. The basic structure of these light-emitting devices is a pair of electrodes sandwiching an organic compound layer (EL layer) containing a light-emitting material between them. By applying a voltage to this element, carriers are injected, and the recombination energy of the carriers is utilized to emit light from the light-emitting material.

[0004] Since such light-emitting devices are self-emitting, they have higher visibility than liquid crystal displays and are suitable as display pixels. Another major advantage of displays using such light-emitting devices is that they do not require a backlight and can be made thin and lightweight. Another characteristic is that they have an extremely fast response time.

[0005] In addition, these light-emitting devices can have light-emitting layers formed continuously in two dimensions, making it possible to emit light in a planar form. This is a feature that is difficult to obtain with point light sources such as incandescent light bulbs or LEDs, or linear light sources such as fluorescent lamps, making them highly valuable as planar light sources for lighting and other applications.

[0006] Thus, displays or lighting devices using light-emitting devices are suitable for use in a variety of electronic devices, and research and development is ongoing to find light-emitting devices with better efficiency and life span.

[0007] Although the characteristics of light-emitting devices have improved remarkably, they are still insufficient to meet high demands for efficiency, durability, and other characteristics. In particular, in order to solve problems such as burn-in, which is still cited as a problem specific to EL, it is better to minimize the decrease in efficiency due to degradation.

[0008] Patent Document 1 discloses a configuration in which a hole-transporting material having a highest occupied molecular orbital (HOMO) level between the HOMO level of the first hole-injection layer and the HOMO level of the host material is provided between a first hole-transporting layer in contact with the hole-injection layer and a light-emitting layer.

[0009] Although the characteristics of light-emitting devices have improved remarkably, they are still insufficient to meet high demands for efficiency, durability, and all other characteristics. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] International Publication No. 2011 / 065136 Brochure Summary of the Invention [Problem to be solved by the invention]

[0011] An object of one embodiment of the present invention is to provide a novel light-emitting device with excellent convenience, usefulness, or reliability.Another object is to provide a novel light-emitting device with excellent convenience, usefulness, or reliability.Another object is to provide a novel electronic device with excellent convenience, usefulness, or reliability.Another object is to provide a novel lighting device with excellent convenience, usefulness, or reliability.

[0012] Note that the description of these problems does not preclude the existence of other problems. Note that one embodiment of the present invention does not necessarily solve all of these problems. Note that problems other than these will become apparent from the description of the specification, drawings, claims, etc., and it is possible to extract problems other than these from the description of the specification, drawings, claims, etc. [Means for solving the problem]

[0013] (1) One embodiment of the present invention is a light-emitting device that includes a first electrode, a second electrode, a unit, and a first layer.

[0014] The second electrode has an area that overlaps the first electrode, and the unit has an area that is sandwiched between the first electrode and the second electrode.

[0015] The unit comprises a second layer and a third layer, the second layer comprising a region sandwiching the third layer between the first electrode, and the second layer including a light emitting material EM.

[0016] The first layer has a region sandwiched between the third layer and the first electrode, and the first layer includes an acceptor material AM and a first material HT1.

[0017] The first layer comprises a first region and a second region.

[0018] The first region comprises an area sandwiched between the second region and the first electrode, the first region including an acceptor material AM at a first concentration C1.

[0019] The second region includes an acceptor material AM at a second concentration C2, the second concentration C2 being greater than zero and less than the first concentration C1.

[0020] This makes it possible to suppress the driving voltage, or to suppress the temperature dependency of the operating characteristics, thereby making it possible to provide a novel light-emitting device that is highly convenient, useful, and reliable.

[0021] (2) In another embodiment of the present invention, the unit includes a fourth layer, the fourth layer including a region sandwiched between the second electrode and the second layer, and the fourth layer includes a third material OMC, the third material OMC being an organic complex of an alkali metal or an organic complex of an alkaline earth metal.

[0022] The third layer comprises a third region and a fourth region, the fourth region comprising a region sandwiched between the second layer and the third region, the fourth region comprising a second material, HT2.

[0023] The first material HT1 has a first HOMO level, and the first HOMO level is not less than −5.7 eV and not more than −5.4 eV.

[0024] The second material HT2 has a second HOMO level, which is in the range of −0.2 eV to 0 eV with respect to the first HOMO level.

[0025] (3) Moreover, one embodiment of the present invention is the above-mentioned light-emitting device, wherein the second layer includes a fourth material HOST, and the fourth material HOST has a first Lowest Unoccupied Molecular Orbital (LUMO) level.

[0026] The fourth layer includes a fifth region and a sixth region.

[0027] The fifth region comprises a region sandwiched between the sixth region and the second layer, the fifth region including a fifth material, ET, and the sixth region including a third material, OMC.

[0028] The fifth material ET has a second LUMO level, which is in the range of -0.4 eV to -0.1 eV, preferably -0.4 eV to -0.15 eV, relative to the first LUMO level.

[0029] (4) Another embodiment of the present invention is the above light-emitting device, in which the first region contains only the material AM having acceptor properties.

[0030] (5) Another embodiment of the present invention is the above light-emitting device, in which the first region is in contact with the first electrode.

[0031] This makes it possible to improve reliability while suppressing an increase in driving voltage, thereby providing a novel light-emitting device that is highly convenient, useful, and reliable.

[0032] (6) Another embodiment of the present invention is a light-emitting device including the above-described light-emitting device and a transistor.

[0033] This makes it possible to improve reliability. Alternatively, it is possible to improve reliability while suppressing an increase in driving voltage. As a result, it is possible to provide a novel light-emitting device that is highly convenient, useful, or reliable.

[0034] (7) Another embodiment of the present invention is an electronic device including the above-described light-emitting device, a sensor, an operation button, a speaker, or a microphone.

[0035] This makes it possible to improve reliability. Alternatively, it is possible to improve reliability while suppressing an increase in driving voltage. As a result, it is possible to provide a novel electronic device that is convenient, useful, or reliable.

[0036] In the drawings accompanying this specification, components are classified by function and shown in block diagrams as independent blocks; however, in actuality, it is difficult to completely separate components by function, and one component may be involved in multiple functions.

[0037] In this specification, the names of the source and drain of a transistor are interchanged depending on the polarity of the transistor and the level of the potential applied to each terminal. In general, in an n-channel transistor, a terminal to which a low potential is applied is called a source, and a terminal to which a high potential is applied is called a drain. In addition, in a p-channel transistor, a terminal to which a low potential is applied is called a drain, and a terminal to which a high potential is applied is called a source. In this specification, for convenience, the connection relationship of a transistor may be described assuming that the source and drain are fixed, but in reality, the names of the source and drain are interchanged according to the above-mentioned potential relationship.

[0038] In this specification, the source of a transistor means a source region that is a part of a semiconductor film that functions as an active layer, or a source electrode connected to the semiconductor film. Similarly, the drain of a transistor means a drain region that is a part of the semiconductor film, or a drain electrode connected to the semiconductor film. Furthermore, the gate means a gate electrode.

[0039] In this specification, a state in which transistors are connected in series means, for example, a state in which only one of the source or drain of a first transistor is connected to only one of the source or drain of a second transistor, and a state in which transistors are connected in parallel means a state in which one of the source or drain of a first transistor is connected to one of the source or drain of a second transistor, and the other of the source or drain of the first transistor is connected to the other of the source or drain of the second transistor.

[0040] In this specification, the term "connection" refers to an electrical connection, and corresponds to a state in which a current, voltage, or potential can be supplied or transmitted. Therefore, the state of being connected does not necessarily refer to a state of being directly connected, but also includes a state of being indirectly connected via a circuit element such as a wiring, resistor, diode, or transistor so that a current, voltage, or potential can be supplied or transmitted.

[0041] In this specification, even if components that are independent on a circuit diagram are connected to each other, in reality, one conductive film may have the functions of multiple components, for example, when part of a wiring functions as an electrode. In this specification, the term "connection" also includes such cases in which one conductive film has the functions of multiple components.

[0042] In this specification, one of a first electrode and a second electrode of a transistor refers to a source electrode, and the other refers to a drain electrode. Effect of the Invention

[0043] According to one embodiment of the present invention, a novel light-emitting device with excellent convenience, usefulness, or reliability can be provided. Alternatively, a novel light-emitting device with excellent convenience, usefulness, or reliability can be provided. Alternatively, a novel electronic device with excellent convenience, usefulness, or reliability can be provided. Alternatively, a novel lighting device with excellent convenience, usefulness, or reliability can be provided.

[0044] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract effects other than these from the description in the specification, drawings, claims, etc. [Brief description of the drawings]

[0045] 1A and 1B are diagrams illustrating a configuration of a light-emitting device according to an embodiment. 2A and 2B are diagrams illustrating a configuration of a light emitting device according to an embodiment. FIG. 3 is a diagram illustrating a configuration of a light-emitting panel according to an embodiment. 4A and 4B are conceptual diagrams of an active matrix type light emitting device. 5A and 5B are conceptual diagrams of an active matrix type light emitting device. FIG. 6 is a conceptual diagram of an active matrix type light emitting device. 7A and 7B are conceptual diagrams of a passive matrix type light emitting device. 8A and 8B are diagrams illustrating a lighting device. 9A to 9D are diagrams showing electronic devices. 10A to 10C are diagrams illustrating an electronic device. FIG. 11 is a diagram showing a lighting device. FIG. 12 is a diagram showing a lighting device. FIG. 13 is a diagram showing an in-vehicle display device and a lighting device. 14A to 14C are diagrams showing electronic devices. 15A and 15B are diagrams illustrating the configuration of a light emitting device according to an embodiment. FIG. 16 is a diagram illustrating the current density-luminance characteristics of the light-emitting device according to the example. FIG. 17 is a diagram illustrating the luminance-current efficiency characteristics of the light-emitting device according to the example. FIG. 18 is a diagram illustrating the voltage-luminance characteristics of the light-emitting device according to the example. FIG. 19 is a diagram illustrating the voltage-current characteristics of the light-emitting device according to the example. FIG. 20 is a diagram illustrating the luminance-external quantum efficiency characteristics of a light-emitting device according to an embodiment. FIG. 21 is a diagram illustrating the emission spectrum of the light-emitting device according to the example. FIG. 22 is a diagram illustrating the normalized luminance-time change characteristics of the light-emitting device according to the example. FIG. 23 is a diagram illustrating the current density-luminance characteristics of the light-emitting device according to the example. FIG. 24 is a diagram illustrating the luminance-current efficiency characteristics of a light-emitting device according to an example. FIG. 25 is a diagram illustrating the voltage-luminance characteristics of the light-emitting device according to the example. FIG. 26 is a diagram illustrating the voltage-current characteristics of the light-emitting device according to the example. FIG. 27 is a diagram illustrating the luminance-external quantum efficiency characteristics of a light-emitting device according to an embodiment. FIG. 28 is a diagram illustrating the emission spectrum of the light-emitting device according to the example. FIG. 29 is a diagram illustrating the normalized luminance-time change characteristics of the light-emitting device according to the example. FIG. 30 is a diagram illustrating the current density-luminance characteristics of the light-emitting device according to the example. FIG. 31 is a diagram illustrating the luminance-current efficiency characteristics of a light-emitting device according to an example. FIG. 32 is a diagram illustrating the voltage-luminance characteristics of the light-emitting device according to the example. FIG. 33 is a diagram illustrating the voltage-current characteristics of the light-emitting device according to the example. FIG. 34 is a diagram illustrating the luminance-external quantum efficiency characteristics of a light-emitting device according to an embodiment. FIG. 35 is a diagram illustrating the emission spectrum of the light-emitting device according to the example. FIG. 36 is a diagram illustrating the normalized luminance-time change characteristics of the light-emitting device according to the example. FIG. 37 is a diagram illustrating the current density-luminance characteristics of the light-emitting device according to the example. FIG. 38 is a diagram illustrating the luminance-current efficiency characteristics of a light-emitting device according to an example. FIG. 39 is a diagram illustrating the voltage-luminance characteristics of the light-emitting device according to the example. FIG. 40 is a diagram illustrating the voltage-current characteristics of the light-emitting device according to the example. FIG. 41 is a diagram illustrating the luminance-external quantum efficiency characteristics of a light-emitting device according to an embodiment. FIG. 42 is a diagram illustrating the emission spectrum of the light-emitting device according to the example. FIG. 43 is a diagram illustrating the normalized luminance-time change characteristics of the light-emitting device according to the example. 44A and 44B are cross-sectional views illustrating the configuration of a light-emitting device according to an embodiment. FIG. 45 is a diagram illustrating the current density-luminance characteristics of a light-emitting device according to an example. FIG. 46 is a diagram illustrating the luminance-current efficiency characteristics of a light-emitting device according to an example. FIG. 47 is a diagram illustrating the voltage-luminance characteristics of a light-emitting device according to an example. FIG. 48 is a diagram illustrating the voltage-current characteristics of the light-emitting device according to the example. FIG. 49 is a diagram illustrating the luminance-external quantum efficiency characteristics of a light-emitting device according to an embodiment. FIG. 50 is a diagram illustrating the emission spectrum of the light-emitting device according to the example. FIG. 51 is a diagram illustrating the normalized luminance-time change characteristics of the light-emitting device according to the example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] A light-emitting device according to one embodiment of the present invention includes a first electrode, a second electrode, a unit, and a first layer. The second electrode includes a region overlapping with the first electrode, the unit includes a region sandwiched between the first electrode and the second electrode, and the unit includes a second layer and a third layer. The second layer includes a region sandwiching the third layer between the first electrode and the second layer, and the second layer includes a light-emitting material. The first layer includes a region sandwiched between the third layer and the first electrode. The first layer includes a material having acceptor properties and a first material, and the first layer includes a first region and a second region. The first region includes a region sandwiched between the second region and the first electrode, the first region includes a material having acceptor properties at a first concentration, and the second region includes a material having acceptor properties at a second concentration. Note that the second concentration is higher than zero and lower than the first concentration.

[0047] This makes it possible to suppress the driving voltage, or to suppress the temperature dependency of the operating characteristics, thereby making it possible to provide a novel light-emitting device that is highly convenient, useful, and reliable.

[0048] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that the form and details of the present invention can be modified in various ways without departing from the spirit and scope of the present invention. Therefore, the present invention is not interpreted as being limited to the description of the embodiments shown below. In the configuration of the invention described below, the same reference numerals are used in common between different drawings for the same parts or parts having similar functions, and repeated explanations are omitted.

[0049] (Embodiment 1) In this embodiment, a structure of a light-emitting device 150 of one embodiment of the present invention will be described with reference to FIG.

[0050] <Configuration Example 1 of Light-Emitting Device 150> A light-emitting device 150 described in this embodiment includes an electrode 101, an electrode 102, a unit 103, and a layer 104 (see FIG. 1A). Note that the electrode 102 has a region overlapping with the electrode 101.

[0051] 《Unit 103 Configuration Example 1》 The unit 103 includes a region sandwiched between the electrode 101 and the electrode 102, and includes a layer 111 and a layer 112. For example, the electrode 101 can be used as an anode, and the electrode 102 can be used as a cathode.

[0052] For example, the unit 103 may include a layer selected from functional layers such as a hole transport layer, an electron transport layer, a carrier blocking layer, and an exciton blocking layer.

[0053] 《Configuration Example 1 of Layer 111》 The layer 111 has a region sandwiching the layer 112 between itself and the electrode 101, and the layer 111 includes a light-emitting material EM.

[0054] The layer 111 contains a host material. The layer 111 can be called a light-emitting layer. The layer 111 is preferably arranged in a region where holes and electrons recombine. This allows the energy generated by the recombination of carriers to be efficiently converted into light and emitted. The layer 111 is preferably arranged away from metals used for electrodes, etc. This allows the quenching phenomenon caused by metals used for electrodes, etc. to be suppressed.

[0055] For example, a fluorescent material, a phosphorescent material, or a material exhibiting thermally delayed fluorescence (TADF) can be used as the luminescent material, which allows the energy generated by the recombination of carriers to be emitted from the luminescent material as light EL1 (see FIG. 1A).

[0056] [Fluorescent substances] A fluorescent light-emitting substance can be used for the layer 111. For example, the following fluorescent light-emitting substances can be used for the layer 111. Note that the fluorescent light-emitting substance is not limited thereto, and various known fluorescent light-emitting substances can be used for the layer 111.

[0057] 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: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-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: 1,6mMemFLPAPrn), 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 -(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: 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]-9H-carbazol-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N'''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-Diphenyl-9H-carbazol-3-amine (abbreviation: 2PCAPA), 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: 2DPAB PhA), 9,10-bis(1,1'-biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N'-diphenylquinacridone, (abbreviation: DPQd), rubrene, 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)acenaphtho[1,2-a]fluoranthene-3,10-diamine Amine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-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]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1 ,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), etc. can be used.

[0058] In particular, condensed aromatic diamine compounds such as pyrenediamine compounds, such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03, are preferred because they have high hole trapping properties and excellent luminous efficiency or reliability.

[0059] [Phosphorescent material 1] Furthermore, a phosphorescent material can be used for the layer 111. For example, the phosphorescent materials exemplified below can be used for the layer 111. Note that the present invention is not limited thereto, and various known phosphorescent materials can be used for the layer 111.

[0060] Specifically, an organometallic iridium complex having a 4H-triazole skeleton or the like can be used for the layer 111. Specifically, tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPrptz-3b)3]), or the like can be used.

[0061] In addition, for example, an organometallic iridium complex having a 1H-triazole skeleton can be used. Specifically, 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-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), etc. can be used.

[0062] Also, for example, an organometallic iridium complex having an imidazole skeleton can be used, such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), etc. can be used.

[0063] In addition, for example, an organometallic iridium complex having a phenylpyridine derivative having an electron-withdrawing group as a ligand can be used. Specifically, bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’]iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}Iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ ]Iridium(III) acetylacetonate (abbreviation: FIracac), etc. can be used.

[0064] These compounds exhibit blue phosphorescence and have a peak emission wavelength in the range of 440 nm to 520 nm.

[0065] [Phosphorescent material 2] Alternatively, for example, an organometallic iridium complex having a pyrimidine skeleton can be used for the layer 111. Specifically, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-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-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]), and the like can be used.

[0066] In addition, for example, an organometallic iridium complex having a pyrazine skeleton can be used, such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), etc.

[0067] In addition, for example, an organometallic iridium complex having a pyridine skeleton can be used. Specifically, 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(acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C 2’ ) Iridium (III) acetylacetonate (abbreviation: [Ir (pq) 2 (acac)]), [2-d3-methyl-(2-pyridinyl-κN) benzofuro [2,3-b] pyridine-κC] bis [2- (5-d3-methyl-2-pyridyl-κN 2) phenyl-κ] iridium (III) (abbreviation: [Ir (5mppy-d3) 2 (mbfpypy-d3)]), [2-d3-methyl- (2-pyridinyl-κN) benzofuro [2,3-b] pyridine-κC] bis [2- (2-pyridinyl-κN) phenyl-κC] iridium (III) (abbreviation: [Ir (ppy) 2 (mbfpypy-d3)]), etc. can be used.

[0068] Also, for example, rare earth metal complexes can be used, such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac)3(Phen)]).

[0069] These compounds mainly exhibit green phosphorescence and have a peak emission wavelength at 500 nm to 600 nm. In addition, organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because they are remarkably excellent in reliability and luminous efficiency.

[0070] [Phosphorescent material 3] Furthermore, for example, an organometallic iridium complex having a pyrimidine skeleton can be used for the layer 111. Specifically, (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]), or the like can be used.

[0071] In addition, for example, an organometallic iridium complex having a pyrazine skeleton can be used. Specifically, (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), and the like can be used.

[0072] In addition, for example, an organometallic iridium complex having a pyridine skeleton can be used. Specifically, tris(1-phenylisoquinolinato-N,C2’ ) Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ ) iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), etc. can be used.

[0073] Also, for example, platinum complexes can be used, such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP).

[0074] Also, for example, rare earth metal complexes can be used, such as tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM)3(Phen)]), tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA)3(Phen)]), and the like.

[0075] These compounds exhibit red phosphorescence and have an emission peak at 600 nm to 700 nm. In addition, organometallic iridium complexes having a pyrazine skeleton can emit red light with a chromaticity suitable for use in display devices.

[0076] [Substances that exhibit thermally activated delayed fluorescence (TADF)] A substance exhibiting thermally activated delayed fluorescence (TADF) (also referred to as a TADF material) can be used for the layer 111. For example, the following TADF materials can be used for the layer 111. Note that the present invention is not limited to these materials, and various known TADF materials can be used for the layer 111.

[0077] For example, fullerene and its derivatives, acridine and its derivatives, eosin derivatives, etc. can be used as TADF materials. In addition, metal-containing porphyrins including magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), etc. can be used as TADF materials.

[0078] Specifically, protoporphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(Etio I)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), and the like, whose structural formulas are shown below, can be used.

[0079] [ka]

[0080] Furthermore, for example, a heterocyclic compound having one or both of a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring can be used as a TADF material.

[0081] Specifically, the structural formulas of the compounds are as follows: 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTzn), 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]-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: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA), etc. can be used.

[0082] [ka]

[0083] The heterocyclic compound has a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring, and therefore has high electron transport and hole transport properties, and is therefore preferred.Among the skeletons having a π-electron deficient heteroaromatic ring, pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton) and triazine skeleton are preferred because they are stable and have good reliability.In particular, benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzofuropyrazine skeleton and benzothienopyrazine skeleton are preferred because they have high acceptor properties and good reliability.

[0084] Among the skeletons having a π-electron-rich heteroaromatic ring, it is preferable to have at least one of the acridine skeleton, the phenoxazine skeleton, the phenothiazine skeleton, the furan skeleton, the thiophene skeleton, and the pyrrole skeleton, since they are stable and reliable. As the furan skeleton, the dibenzofuran skeleton is preferable, and as the thiophene skeleton, the dibenzothiophene skeleton is preferable. As the pyrrole skeleton, the indole skeleton, the carbazole skeleton, the indolocarbazole skeleton, the bicarbazole skeleton, and the 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferable.

[0085] In addition, a substance in which a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring are directly bonded is particularly preferable because the electron donating property of the π-electron rich heteroaromatic ring and the electron accepting property of the π-electron deficient heteroaromatic ring are both strong, and the energy difference between the S1 level and the T1 level is small, so that thermally activated delayed fluorescence can be efficiently obtained. In addition, an aromatic ring to which an electron withdrawing group such as a cyano group is bonded may be used instead of the π-electron deficient heteroaromatic ring. In addition, an aromatic amine skeleton, a phenazine skeleton, etc. can be used as the π-electron rich skeleton.

[0086] In addition, examples of the π-electron-deficient skeleton that can be used include a xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane or boranthrene, an aromatic ring or a heteroaromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, and a sulfone skeleton.

[0087] In this way, a π-electron deficient skeleton and a π-electron rich skeleton can be used in place of at least one of a π-electron deficient heteroaromatic ring and a π-electron rich heteroaromatic ring.

[0088] TADF materials are materials that have a small difference between the S1 and T1 levels and have the function of converting triplet excitation energy to singlet excitation energy by reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy by a small amount of thermal energy (reverse intersystem crossing), and singlet excitation states can be generated efficiently. In addition, triplet excitation energy can be converted into light emission.

[0089] In addition, exciplexes (also called exciplexes), which form an excited state with two types of substances, have an extremely small difference between the S1 level and the T1 level and function as TADF materials that can convert triplet excitation energy into singlet excitation energy.

[0090] As an index of the T1 level, a phosphorescence spectrum observed at low temperatures (for example, 77 K to 10 K) may be used. For a TADF material, when a tangent line is drawn at the base of the short wavelength side of the fluorescence spectrum, and the energy of the wavelength of the extrapolated line is taken as the S1 level, and a tangent line is drawn at the base of the short wavelength side of the phosphorescence spectrum, and the energy of the wavelength of the extrapolated line is taken as the T1 level, the difference between S1 and T1 is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0091] In addition, when a TADF material is used as a light-emitting material, the S1 level of the host material is preferably higher than the S1 level of the TADF material, and the T1 level of the host material is preferably higher than the T1 level of the TADF material.

[0092] <Configuration Example 1 of Layer 104> Layer 104 comprises a region sandwiched between layer 112 and electrode 101 (see FIG. 1A).

[0093] The layer 104 includes a material AM having an acceptor property and a material HT1. Note that a material including a material AM having an acceptor property and a material HT1 can be called a composite material.

[0094] {Acceptor materials AM} For example, a compound having an electron-withdrawing group (a halogen group or a cyano group) can be used as a material having acceptor properties. Note that organic compounds having acceptor properties are easy to evaporate and form into films. This can increase the productivity of light-emitting devices.

[0095] Specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, and the like can be used as materials having acceptor properties.

[0096] In particular, a compound in which an electron-withdrawing group is bonded to a condensed aromatic ring having a plurality of heteroatoms, such as HAT-CN, is preferred because it is thermally stable.

[0097] In addition, radialene derivatives having an electron-withdrawing group (particularly a halogen group such as a fluoro group or a cyano group)[3] are preferred because they have very high electron-accepting properties.

[0098] Specifically, α,α',α''-1,2,3-cyclopropane triylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropane triylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α''-1,2,3-cyclopropane triylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], etc. can be used.

[0099] 《Material HT1》 For example, a material having a hole transporting property can be used as the material HT1.

[0100] [Hole-transporting materials] As a material having hole transport properties, 1×10 -6 cm 2 For example, a compound having an aromatic amine skeleton, a compound having a carbazole skeleton, a compound having a thiophene skeleton, a compound having a furan skeleton, or the like can be used.

[0101] As the material having a hole transporting property, an amine compound or an organic compound having a π-electron-rich heteroaromatic ring skeleton is preferable. For example, a compound having an aromatic amine skeleton, a compound having a carbazole skeleton, a compound having a thiophene skeleton, a compound having a furan skeleton, etc. can be used.

[0102] Examples of compounds having an aromatic amine skeleton 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-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), and 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP). , 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: 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)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), etc. can be used.

[0103] Examples of compounds having a carbazole skeleton that can be used include 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), and 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP).

[0104] Examples of compounds having a thiophene skeleton that can be used include 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV).

[0105] Examples of compounds having a furan skeleton that can be used include 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 the like.

[0106] Among the above, the compounds having an aromatic amine skeleton or the compounds having a carbazole skeleton are preferable because they have good reliability, high hole transport properties, and contribute to reducing the driving voltage.

[0107] <<Configuration Example 2 of Layer 104>> The layer 104 includes a region 104A and a region 104B. The region 104A includes a region sandwiched between the region 104B and the electrode 101, and the region 104A includes a material AM having acceptor properties at a concentration C1. In other words, the layer 104 has a distribution in concentration including the material having acceptor properties.

[0108] Region 104B includes an acceptor material AM at a concentration C2, which is greater than zero and less than concentration C1.

[0109] This makes it possible to suppress the driving voltage, or to suppress the temperature dependency of the operating characteristics, thereby making it possible to provide a novel light-emitting device that is highly convenient, useful, and reliable.

[0110] <Configuration Example 2 of Light-Emitting Device 150> In addition, in the light-emitting device 150 according to one embodiment of the present invention, the unit 103 includes a layer 113 (see FIG. 1A).

[0111] <<Configuration Example 1 of Layer 113>> The layer 113 comprises a region sandwiched between the electrode 102 and the layer 111, and the layer 113 includes a material OMC, which is an organic complex of an alkali metal or an organic complex of an alkaline earth metal.

[0112] A material containing an alkali metal, an alkali metal compound, or an alkali metal complex, and a substance having an electron transporting property can be used as the material having an electron transporting property. In particular, when a substance having a relatively deep HOMO level of -5.7 eV or more and -5.4 eV or less is used as the composite material of the hole injection layer, the reliability of the light-emitting device can be improved. It is more preferable that the HOMO level of the material having an electron transporting property is -6.0 eV or more.

[0113] For example, it is preferable that the compound contains an 8-hydroxyquinolinato structure. Specifically, 8-hydroxyquinolinato-lithium (abbreviation: Liq), 8-hydroxyquinolinato-sodium (abbreviation: Naq), etc. can be used.

[0114] In particular, a complex of a monovalent metal ion, particularly a complex of lithium, is preferred, and Liq is more preferred. When the 8-hydroxyquinolinato structure is included, its methyl-substituted derivative (e.g., 2-methyl-substituted derivative or 5-methyl-substituted derivative) can also be used. In addition, it is preferred that the alkali metal or alkaline earth metal simple substance, compound, or complex in the electron transport layer have a concentration difference (including the case of 0) in the thickness direction.

[0115] <<Configuration Example 1 of Layer 112>> The layer 112 includes a region 112A and a region 112B. Note that the region 112B includes a region sandwiched between the layer 111 and the region 112A, and the region 112B includes the material HT2.

[0116] 《Material HT2》 A material having a hole-transporting property can be used for the layer 112. For example, a material having a hole-transporting property that can be used for the layer 104 can be used for the material HT2. The layer 112 can be referred to as a hole-transporting layer. Note that it is preferable that a substance having a larger band gap than the band gap of the light-emitting material contained in the layer 111 is used for the region 112B. This can suppress energy transfer from excitons generated in the layer 111 to the region 112B.

[0117] The material HT1 has a first HOMO level HOMO1, which is −5.7 eV to −5.4 eV (see FIG. 1B). The material HT2 has a second HOMO level HOMO2, which is −0.2 eV to 0 eV with respect to the first HOMO level HOMO1.

[0118] <Configuration Example 3 of Light-Emitting Device 150> Also, in the light-emitting device 150 according to one embodiment of the present invention, the layer 111 includes a host material HOST, which has a first LUMO level LUMO1 (see FIG. 1B).

[0119] 《Host material HOST》 A material having a carrier transporting property can be used as the host material HOST. For example, a material having a hole transporting property, a material having an electron transporting property, a TADF material, a material having an anthracene skeleton, a mixed material, or the like can be used as the host material.

[0120] [Hole-transporting materials] For example, the material having a hole transporting property that can be used for the layer 112 can be used for the host material HOST.

[0121] [Electron transporting materials] An organic compound having an anthracene skeleton can be used as a material having an electron transporting property, and in particular, an organic compound having both an anthracene skeleton and a heterocyclic skeleton can be preferably used.

[0122] For example, an organic compound containing both an anthracene skeleton and a nitrogen-containing 5-membered ring skeleton, or an organic compound containing both an anthracene skeleton and a nitrogen-containing 6-membered ring skeleton can be used. Alternatively, an organic compound containing both an anthracene skeleton and a nitrogen-containing 5-membered ring skeleton containing two heteroatoms in the ring, or an organic compound having a nitrogen-containing 6-membered ring skeleton containing two heteroatoms in the ring can be used. Specifically, a pyrazole ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, or the like can be suitably used as the heterocyclic skeleton.

[0123] In addition, as a material having electron transport properties, a metal complex or an organic compound having a π-electron deficient heteroaromatic ring skeleton is preferable. As an organic compound having a π-electron deficient heteroaromatic ring skeleton, for example, a heterocyclic compound having a polyazole skeleton, a heterocyclic compound having a diazine skeleton, or a heterocyclic compound having a pyridine skeleton is preferable. In particular, a heterocyclic compound having a diazine skeleton or a heterocyclic compound having a pyridine skeleton is preferable because of its good reliability. In addition, a heterocyclic compound having a diazine (pyrimidine or pyrazine) skeleton has high electron transport properties and can reduce the driving voltage.

[0124] Examples of metal complexes that can be used include bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), 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: ZnPBO), and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0125] Examples of heterocyclic compounds having a polyazole skeleton include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: O XD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), etc. can be used.

[0126] Examples of heterocyclic compounds having a diazine skeleton include 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h ]quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzo[h]quinazoline (abbreviation: 4,8mDBtP2Bqn), etc. can be used.

[0127] Examples of heterocyclic compounds having a pyridine skeleton that can be used include 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), and the like.

[0128] [TADF material] The TADF materials exemplified above can be used as the host material. When a TADF material is used as the host material, the triplet excitation energy generated in the TADF material is converted to singlet excitation energy by reverse intersystem crossing, and the energy is then transferred to the light-emitting material, thereby improving the light-emitting efficiency of the light-emitting device. In this case, the TADF material functions as an energy donor, and the light-emitting material functions as an energy acceptor.

[0129] This is very effective when the luminescent material is a fluorescent luminescent material. In this case, in order to obtain high luminous efficiency, the S1 level of the TADF material is preferably higher than the S1 level of the fluorescent luminescent material. In addition, the T1 level of the TADF material is preferably higher than the S1 level of the fluorescent luminescent material. Therefore, the T1 level of the TADF material is preferably higher than the T1 level of the fluorescent luminescent material.

[0130] It is also preferable to use a TADF material that emits light at a wavelength that overlaps with the wavelength of the lowest energy absorption band of the fluorescent material, since this allows for smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient emission of light.

[0131] In addition, in order to efficiently generate singlet excitation energy from triplet excitation energy by reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. In addition, it is preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent material. For this purpose, it is preferable that the fluorescent material has a protective group around the luminophore (the skeleton that causes light emission) of the fluorescent material. As the protective group, a substituent that does not have a π bond is preferable, and a saturated hydrocarbon is preferable, specifically, an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a trialkylsilyl group having 3 to 10 carbon atoms are mentioned, and it is more preferable that there are a plurality of protective groups. Since a substituent that does not have a π bond has poor function of transporting carriers, the distance between the TADF material and the luminophore of the fluorescent material can be increased without affecting carrier transport or carrier recombination.

[0132] Here, the luminophore refers to an atomic group (skeleton) that causes light emission in a fluorescent substance. The luminophore preferably has a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a condensed aromatic ring or a condensed heteroaromatic ring.

[0133] Examples of the condensed aromatic ring or condensed heteroaromatic ring include a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, a phenothiazine skeleton, etc. In particular, fluorescent substances having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, or a naphthobisbenzofuran skeleton are preferred because they have a high fluorescence quantum yield.

[0134] [Materials with anthracene skeleton] When a fluorescent substance is used as the light-emitting substance, a material having an anthracene skeleton is preferably used as the host material. When a substance having an anthracene skeleton is used as the host material of the fluorescent substance, it is possible to realize a light-emitting layer having good luminous efficiency and durability.

[0135] As a substance having an anthracene skeleton used as a host material, a substance having a diphenylanthracene skeleton, particularly a substance having a 9,10-diphenylanthracene skeleton, is preferable because it is chemically stable. In addition, when the host material has a carbazole skeleton, it is preferable because the injection and transport properties of holes are improved, but when the host material contains a benzocarbazole skeleton in which a benzene ring is further condensed to carbazole, the HOMO becomes shallower by about 0.1 eV than that of carbazole, making it easier for holes to enter, which is more preferable.

[0136] In particular, when the host material contains a dibenzocarbazole skeleton, the HOMO is shallower by about 0.1 eV than that of carbazole, making it easier for holes to enter, and it is also preferable because it has excellent hole transport properties and high heat resistance. Therefore, a more preferable host material is a substance that simultaneously has a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton). Note that, from the viewpoint of the hole injection / transport properties, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton.

[0137] Examples of substances having an anthracene skeleton include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g ]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl}anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), etc. can be used.

[0138] In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA show very good properties.

[0139] [Mixed material composition example 1] A material in which a plurality of kinds of substances are mixed can be used as the host material. For example, a material in which a material having an electron transporting property and a material having a hole transporting property are mixed can be suitably used as the host material. By mixing a material having an electron transporting property and a material having a hole transporting property, the carrier transporting property of the layer 111 can be easily adjusted. In addition, the recombination region can be easily controlled. The weight ratio of the material having a hole transporting property and the material having an electron transporting property contained in the mixed material may be material having a hole transporting property:material having an electron transporting property=1:19 to 19:1.

[0140] [Mixed material composition example 2] A material mixed with a phosphorescent material can be used as a host material. The phosphorescent material can be used as an energy donor that provides excitation energy to a fluorescent material when the fluorescent material is used as a light-emitting material.

[0141] In addition, a mixed material containing a material that forms an exciplex can be used as the host material. For example, a material in which the emission spectrum of the formed exciplex overlaps with the wavelength of the lowest energy absorption band of the light-emitting substance can be used as the host material. This makes energy transfer smooth, and can improve the light-emitting efficiency. Or, the driving voltage can be suppressed.

[0142] At least one of the materials forming the exciplex may be a phosphorescent material, which allows the triplet excitation energy to be efficiently converted into singlet excitation energy by reverse intersystem crossing.

[0143] As a combination of materials that efficiently form an exciplex, it is preferable that the HOMO level of the material having hole transport properties is equal to or higher than the HOMO level of the material having electron transport properties. It is also preferable that the LUMO level of the material having hole transport properties is equal to or higher than the LUMO level of the material having electron transport properties. The LUMO level and HOMO level of the material can be derived from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement.

[0144] The formation of an exciplex can be confirmed, for example, by comparing the emission spectrum of a material having hole transport properties, the emission spectrum of a material having electron transport properties, and the emission spectrum of a mixed film obtained by mixing these materials, and observing the phenomenon that the emission spectrum of the mixed film shifts to a longer wavelength than the emission spectrum of each material (or has a new peak on the longer wavelength side). Alternatively, the formation of an exciplex can be confirmed by comparing the transient photoluminescence (PL) of a material having hole transport properties, the transient PL of a material having electron transport properties, and the transient PL of a mixed film obtained by mixing these materials, and observing the difference in transient response, such as the transient PL lifetime of the mixed film having a longer lifetime component than the transient PL lifetime of each material, or the proportion of delayed components becoming larger. The above-mentioned transient PL may also be read as transient electroluminescence (EL). That is, the formation of an exciplex can also be confirmed by comparing the transient EL of a material having hole transport properties, the transient EL of a material having electron transport properties, and the transient EL of a mixed film obtained by mixing these materials, and observing the difference in transient response.

[0145] 《Unit 103 Configuration Example 2》 The unit 103 also comprises a layer 113 (see FIG. 1A).

[0146] <<Configuration Example 2 of Layer 113>> For example, a material having an electron-transporting property can be used for the layer 113. The layer 113 can be referred to as an electron-transporting layer. Note that a substance having a larger band gap than that of the light-emitting material contained in the layer 111 is preferably used for the layer 113. This can suppress energy transfer from excitons generated in the layer 111 to the layer 113.

[0147] [Electron transporting materials] Materials with electron transport properties have an electron mobility of 1×10 at a square root of the electric field strength [V / cm] of 600. -7 cm 2 / Vs or more, 5×10 -5 cm 2 By suppressing the electron transportability in the electron transport layer, the amount of electrons injected into the light-emitting layer can be controlled. Alternatively, the light-emitting layer can be prevented from becoming in an electron excess state.

[0148] For example, a material having an electron-transporting property that can be used for the layer 111 can be used for the layer 113. Specifically, a material having an electron-transporting property that can be used for a host material can be used for the layer 113.

[0149] <<Configuration Example 3 of Layer 113>> The layer 113 includes a region 113A and a region 113B. The region 113A includes a region sandwiched between the region 113B and the layer 111, and the region 113A includes the material ET. Note that the region 113B includes the material OMC.

[0150] The material ET has a second LUMO level LUMO2 which is in the range of ≧−0.4 eV to ≦−0.1 eV, preferably ≧−0.4 eV to ≦−0.15 eV, relative to the first LUMO level LUMO1 (see FIG. 1B).

[0151] <<Configuration Example 3 of Layer 104>> In addition, in one embodiment of the present invention, the region 104A is in contact with the electrode 101.

[0152] This makes it easier to inject holes from electrode 101 into region 104A. Alternatively, reliability can be improved while suppressing the driving voltage. As a result, a novel light-emitting device that is highly convenient, useful, and reliable can be provided.

[0153] Example of the configuration of electrode 101 For example, a conductive material can be used for the electrode 101. Specifically, a metal, an alloy, a conductive compound, a mixture thereof, or the like can be used for the electrode 101. For example, a material having a work function of 4.0 eV or more can be suitably used.

[0154] For example, indium oxide-tin oxide (ITO), indium oxide-tin oxide containing silicon or silicon oxide, indium oxide-zinc oxide, indium oxide containing tungsten oxide and zinc oxide (IWZO), etc. can be used.

[0155] Also, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or a nitride of a metal material (for example, titanium nitride), etc. can be used. Alternatively, graphene can be used.

[0156] Example of the configuration of the electrode 102 For example, a conductive material can be used for the electrode 102. Specifically, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like can be used for the electrode 102. For example, a material having a smaller work function than the electrode 101 can be used for the electrode 102. Specifically, a material having a work function of 3.8 eV or less can be suitably used.

[0157] For example, the electrode 102 can be made of elements belonging to Group 1 of the periodic table, elements belonging to Group 2 of the periodic table, rare earth metals, and alloys containing these.

[0158] Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), strontium (Sr), europium (Eu), ytterbium (Yb), and alloys containing these (MgAg, AlLi) can be used for the electrode 102.

[0159] Example of Layer 105 The light-emitting device 150 described in this embodiment includes a layer 105. The layer 105 includes a region sandwiched between the electrode 102 and the unit 103.

[0160] For example, a material having an electron injecting property can be used for the layer 105. Specifically, a substance having a donor property can be used for the layer 105. Alternatively, a composite material in which a material having an electron transporting property contains a substance having a donor property can be used for the layer 105. This can facilitate injection of electrons from the electrode 102, for example. Alternatively, the driving voltage of the light-emitting device can be reduced. Alternatively, various conductive materials can be used for the electrode 102 regardless of the magnitude of the work function. Specifically, Al, Ag, ITO, indium oxide-tin oxide containing silicon or silicon oxide, or the like can be used for the electrode 102.

[0161] [Electron injecting material 1] For example, an alkali metal, an alkaline earth metal, a rare earth metal, or a compound thereof can be used as the substance having donor properties. Alternatively, an organic compound such as tetrathianaphthacene (abbreviation: TTN), nickelocene, or decamethylnickelocene can be used as the substance having donor properties.

[0162] Specifically, alkali metal compounds (including oxides, halides, and carbonates), alkaline earth metal compounds (including oxides, halides, and carbonates), or rare earth metal compounds (including oxides, halides, and carbonates), etc., can be used as materials having electron injection properties.

[0163] Specifically, lithium oxide, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), lithium carbonate, cesium carbonate, 8-hydroxyquinolinato-lithium (abbreviation: Liq), and the like can be used as the material having electron injection properties.

[0164] [Electron injecting material 2] For example, a composite material containing an alkali metal or an alkaline earth metal or a compound thereof and a substance having an electron transporting property can be used as a material having an electron injecting property.

[0165] For example, a material having an electron transporting property that can be used for the unit 103 can be used for a material having an electron injecting property.

[0166] In addition, a material containing a microcrystalline alkali metal fluoride and a substance having electron transport properties, or a material containing a microcrystalline alkaline earth metal fluoride and a substance having electron transport properties can be used as a material having electron injection properties.

[0167] In particular, a material containing 50 wt % or more of an alkali metal fluoride or an alkaline earth metal fluoride can be preferably used. Alternatively, an organic compound having a bipyridine skeleton can be preferably used. This can reduce the refractive index of the layer 105. Alternatively, the external quantum efficiency of the light-emitting device can be improved.

[0168] [Electron injecting material 3] In addition, an electride can be used as a material having an electron injection property. For example, a substance in which electrons are added to a mixed oxide of calcium and aluminum at a high concentration can be used as a material having an electron injection property.

[0169] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0170] (Embodiment 2) In this embodiment, a structure of a light-emitting device 150 of one embodiment of the present invention will be described with reference to FIG. 2A.

[0171] FIG. 2A is a cross-sectional view illustrating a configuration of a light-emitting device according to one embodiment of the present invention, which has a configuration different from that illustrated in FIG.

[0172] <Configuration Example of Light Emitting Device 150> The light-emitting device 150 described in this embodiment includes an electrode 101, an electrode 102, a unit 103, an intermediate layer 106, and a unit 103(12) (see FIG. 2A). In addition, a layer 104(12) and a layer 105(12) can be used.

[0173] Note that a structure similar to that of the layer 104 described in Embodiment 1 can be used for the layer 104(12), and a structure similar to that of the layer 105 described in Embodiment 1 can be used for the layer 105(12).

[0174] Unit 103 comprises an area sandwiched between electrode 101 and electrode 102, unit 103(12) comprises an area sandwiched between electrode 101 and unit 103, and intermediate layer 106 comprises an area sandwiched between unit 103(12) and unit 103. Additionally, layer 105(12) comprises an area sandwiched between unit 103(12) and intermediate layer 106.

[0175] The light emitting device 150 has a plurality of stacked units. The number of stacked units is not limited to two, and three or more units can be stacked. A configuration including the intermediate layer 106 and a plurality of units may be called a stacked light emitting device or a tandem light emitting device. This allows high luminance emission while keeping the current density low. Alternatively, reliability can be improved. Alternatively, the driving voltage can be reduced compared with the same luminance. Alternatively, power consumption can be suppressed.

[0176] Example of Unit 103(12) configuration The configuration that can be used for the unit 103 can be used for the unit 103(12). For example, the same configuration as the unit 103 can be used for the unit 103(12).

[0177] Alternatively, a configuration different from that of the unit 103 can be used for the unit 103(12). For example, a configuration with an emission color different from that of the unit 103 can be used for the unit 103(12). Specifically, a unit 103 that emits red light and green light, and a unit 103(12) that emits blue light can be used. This makes it possible to provide a light-emitting device that emits light of a desired color. Or, for example, a light-emitting device that emits white light can be provided.

[0178] Example of the configuration of the intermediate layer 106 The intermediate layer 106 includes a layer 104 and a layer 106 A. The intermediate layer 106 has a function of supplying electrons to one of the unit 103 and the unit 103(12) and supplying holes to the other.

[0179] The layer 104 includes a material AM having acceptor properties and a material HT1, and includes a region 104A and a region 104B. The region 104A also includes a region sandwiched between the region 104B and the electrode 101, and the region 104A includes the material AM having acceptor properties at a concentration C1.

[0180] Region 104B includes an acceptor material AM at a concentration C2, which is greater than zero and less than concentration C1.

[0181] This makes it possible to suppress the driving voltage, or to suppress the temperature dependency of the operating characteristics, thereby making it possible to provide a novel light-emitting device that is highly convenient, useful, and reliable.

[0182] The layer 104 can be called a charge generation layer. The charge generation layer has a function of supplying electrons to the anode side and holes to the cathode side by applying a voltage. Specifically, it can supply electrons to the unit 103 (12) arranged on the anode side.

[0183] Example of the structure of layer 106A Layer 106A includes an area sandwiched between layer 104 and unit 103 (12). Layer 106A can be referred to as, for example, an electronic relay layer.

[0184] For example, a substance having electron transport properties can be used in the electron relay layer. This allows the layer in contact with the anode side of the electron relay layer to be separated from the layer in contact with the cathode side of the electron relay layer. Alternatively, the interaction between the layer in contact with the anode side of the electron relay layer and the layer in contact with the cathode side of the electron relay layer can be reduced. Alternatively, electrons can be smoothly supplied to the layer in contact with the anode side of the electron relay layer.

[0185] For example, a substance having an electron-transporting property can be preferably used for the electron-relay layer. Specifically, a substance having a LUMO level between the LUMO level of the material AM having an acceptor property used for the layer 104 and the LUMO level of the material HT1 having a hole-transporting property used for the layer 104 can be preferably used for the electron-relay layer.

[0186] For example, a substance having an electron transporting property and having a LUMO level in the range of −5.0 eV or more, preferably −5.0 eV or more and −3.0 eV or less, can be used for the electron-relay layer.

[0187] Specifically, phthalocyanine-based materials can be used in the electron relay layer, or metal complexes having metal-oxygen bonds and aromatic ligands can be used in the electron relay layer.

[0188] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0189] (Embodiment 3) In this embodiment, a structure of a light-emitting device 150 of one embodiment of the present invention will be described with reference to FIG. 2B.

[0190] FIG. 2B is a cross-sectional view illustrating a configuration of a light-emitting device according to one embodiment of the present invention, which has a configuration different from that illustrated in FIG.

[0191] <Configuration Example of Light Emitting Device 150> Moreover, the light-emitting device 150 described in this embodiment includes an electrode 101, an electrode 102, a unit 103, a layer 104, and an intermediate layer 106 (see FIG. 2B).

[0192] 1 in that light-emitting device 150 has intermediate layer 106 between layer 105 and electrode 102. Here, the differences will be described in detail, and the above description will be used for parts where a similar configuration can be used.

[0193] Example of the configuration of the intermediate layer 106 Intermediate layer 106 comprises an area sandwiched between unit 103 and electrode 102, and intermediate layer 106 comprises layer 106A and layer 106B.

[0194] Example of the structure of layer 106A Layer 106A has a region sandwiched between layer 106B and layer 105. For example, the electron relay layer described in the second embodiment can be used for layer 106A.

[0195] Example of configuration of layer 106B The layer 106B can be referred to as, for example, a charge generation layer. The charge generation layer has a function of supplying electrons to the anode side and holes to the cathode side by applying a voltage. Specifically, it can supply electrons to the unit 103 arranged on the anode side.

[0196] For example, a composite material exemplified as a material having a hole injection property can be used for the charge generation layer. For example, a stacked film in which a film containing the composite material and a film containing a material having a hole transport property are stacked can be used for the charge generation layer.

[0197] <Method of Manufacturing Light-Emitting Device 150> For example, the layers of the electrode 101, the electrode 102, the unit 103, and the intermediate layer 106 can be formed by using a dry method, a wet method, a vapor deposition method, a droplet discharge method, a coating method, a printing method, or the like. Similarly, the layers of the unit 103 (12) can also be formed by using similar methods. Different methods can also be used to form each component.

[0198] Specifically, the light emitting device 150 can be produced using a vacuum deposition apparatus, an inkjet apparatus, a coating apparatus such as a spin coater, a gravure printing apparatus, an offset printing apparatus, a screen printing apparatus, or the like.

[0199] For example, the electrode can be formed by a wet method using a paste of a metal material or a sol-gel method. Specifically, an indium oxide-zinc oxide film can be formed by a sputtering method using a target containing 1 to 20 wt% zinc oxide added to indium oxide. Also, an indium oxide (IWZO) film containing tungsten oxide and zinc oxide can be formed by a sputtering method using a target containing 0.5 to 5 wt% tungsten oxide and 0.1 to 1 wt% zinc oxide to indium oxide.

[0200] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0201] (Embodiment 4) In this embodiment, a structure of a light-emitting panel 700 of one embodiment of the present invention will be described with reference to FIG.

[0202] <Configuration example of light-emitting panel 700> Light-emitting panel 700 described in this embodiment has light-emitting device 150 and light-emitting device 150(2) (FIG. 3).

[0203] For example, the light-emitting device described in any one of the first to third embodiments can be used as the light-emitting device 150 .

[0204] <Configuration Example of Light-Emitting Device 150(2)> The light-emitting device 150(2) described in this embodiment has an electrode 101(2), an electrode 102, and a unit 103(2) (see FIG. 3). For example, a part of the configuration of the light-emitting device 150 can be used as a part of the configuration of the light-emitting device 150(2). This allows a part of the configuration to be shared. Alternatively, the manufacturing process can be simplified.

[0205] 《Example of Unit 103(2)》 Unit 103(2) includes a region sandwiched between electrode 101(2) and electrode 102. Unit 103(2) also includes layer 111(2). For example, a light-emitting material that emits light of a different color from that of layer 111 included in unit 103 can be used for layer 111(2).

[0206] The unit 103(2) has a single layer structure or a laminated structure. For example, a layer selected from functional layers such as a hole transport layer, an electron transport layer, a carrier block layer, and an exciton block layer can be used for the unit 103(2).

[0207] Unit 103(2) includes a region where electrons injected from one electrode recombine with holes injected from the other electrode, for example, a region where holes injected from electrode 101(2) recombine with electrons injected from electrode 102.

[0208] Example of Layer 104(2) The layer 104(2) has a region sandwiched between the electrode 101 and the unit 103. The layer 104(2) can be called a hole-injecting layer. For example, a material having a hole-injecting property can be used for the layer 104(2).

[0209] Specifically, a material having an acceptor property and a composite material can be used for the layer 104(2). Note that an organic compound and an inorganic compound can be used for the material having an acceptor property. When an electric field is applied, the material having an acceptor property can extract electrons from the adjacent hole transport layer (or hole transport material).

[0210] [Example 1 of materials with hole injection properties] A material having an acceptor property can be used as a material having a hole injection property. This makes it easier to inject holes from the electrode 101, for example. Alternatively, the driving voltage of the light-emitting device can be reduced.

[0211] For example, the material having an acceptor property described in Embodiment 1 can be used as the material having a hole-injecting property.

[0212] Furthermore, molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, or the like can be used as the material having acceptor properties.

[0213] In addition, phthalocyanine complex compounds such as phthalocyanine (abbreviation: HPc) or copper phthalocyanine (CuPc), and compounds having an aromatic amine skeleton such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB) and N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD) can be used.

[0214] Also, polymers such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS) can be used.

[0215] [Example 2 of materials with hole injection properties] A composite material can be used as a material having a hole injection property. For example, a composite material in which a material having a hole transport property contains a material having an acceptor property can be used. This allows a material for forming the electrode to be selected from a wide range regardless of the work function. Alternatively, not only a material having a high work function but also a material having a low work function can be used for the electrode 101.

[0216] Various organic compounds can be used as the material having the hole transport property of the composite material. For example, compounds having an aromatic amine skeleton, carbazole derivatives, aromatic hydrocarbons, polymer compounds (oligomers, dendrimers, polymers, etc.), etc. can be used as the material having the hole transport property of the composite material. -6 cm 2 A substance having a hole mobility of .beta. / Vs or more can be suitably used.

[0217] In addition, for example, a substance having a relatively deep HOMO level of -5.7 eV or more and -5.4 eV or less can be suitably used as a material having a hole transporting property of the composite material. This can facilitate injection of holes into the hole transporting layer. Or, the reliability of the light-emitting device can be improved.

[0218] Examples of compounds having an aromatic amine skeleton that can be used include N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B).

[0219] Examples of the carbazole derivative include 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenyl Carbazole (abbreviation: PCzPCN1), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(N-carbazolyl)]phenyl-10-phenylanthracene (abbreviation: CzPA), 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene, and the like can be used.

[0220] Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 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, 10,10'-diphenyl-9,9'-bianthryl, 10,10'-bis(2-phenylphenyl)-9,9'-bianthryl, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthryl, anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, and the like can be used.

[0221] Examples of aromatic hydrocarbons having a vinyl group that can be used include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA).

[0222] For example, pentacene, coronene, etc. may also be used.

[0223] Examples of polymer compounds that can be used include poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD).

[0224] For example, a substance having any one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton can be suitably used as a material having hole transport properties of the composite material. In addition, a substance having an aromatic amine having a substituent containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine having a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group can be used. Note that the use of a substance having an N,N-bis(4-biphenyl)amino group can improve the reliability of the light-emitting device.

[0225] Examples of the hole transporting material of these composite materials include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-yl, zo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophene-4-yl)phenyl] -N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβN B-03), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: ''-Phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris( 1,1'-biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-diphenyl-4'-(2-naphthyl)-4''-{9-(4-biphenylyl)carbazole}triphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi(9H-fluorene)-2-amine (abbreviation: PCBNBSF), N,N-bis(4-biphenylyl)-9 ,9'-Spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(1,1'-biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi(9H-fluorene)-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(dibenzofuran-4-yl)-9,9-Dimethyl-9H-fluoren-2-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenyl 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl) N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluoren-2-amine (abbreviation: PCBBiF), N,N-bis(9,9- Dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, etc. can be used.

[0226] [Example 3 of materials with hole injection properties] A composite material containing a material having a hole transporting property, a material having an accepting property, and a fluoride of an alkali metal or an alkaline earth metal can be used as the material having a hole injecting property. In particular, a composite material having an atomic ratio of fluorine atoms of 20% or more can be preferably used. This can reduce the refractive index of the layer 111. Alternatively, a layer having a low refractive index can be formed inside the light-emitting device. Alternatively, the external quantum efficiency of the light-emitting device can be improved.

[0227] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0228] (Embodiment 5) In this embodiment, a light-emitting device using the light-emitting device described in any one of Embodiments 1 to 4 will be described.

[0229] In this embodiment, a light-emitting device manufactured using the light-emitting device described in any one of Embodiments 1 to 4 will be described with reference to FIG. 4. FIG. 4A is a top view showing the light-emitting device, and FIG. 4B is a cross-sectional view taken along the lines AB and CD in FIG. 4A. This light-emitting device includes a driver circuit section (source line driver circuit 601), a pixel section 602, and a driver circuit section (gate line driver circuit 603) shown by dotted lines to control light emission from the light-emitting device. Reference numeral 604 denotes a sealing substrate, 605 denotes a sealant, and the inside surrounded by the sealant 605 is a space 607.

[0230] The lead wiring 608 is a wiring for transmitting signals input to the source line driving circuit 601 and the gate line driving circuit 603, and receives a video signal, a clock signal, a start signal, a reset signal, and the like from an FPC (flexible printed circuit) 609 serving as an external input terminal. Although only an FPC is shown here, a printed wiring board (PWB) may be attached to this FPC. In this specification, the light emitting device includes not only the light emitting device itself, but also a state in which an FPC or a PWB is attached to it.

[0231] Next, the cross-sectional structure will be described with reference to Fig. 4B. A driver circuit section and a pixel section are formed on an element substrate 610, but here, a source line driver circuit 601, which is the driver circuit section, and one pixel in a pixel section 602 are shown.

[0232] The element substrate 610 may be made of a substrate made of glass, quartz, organic resin, metal, alloy, semiconductor, or a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl fluoride), polyester, acrylic resin, or the like.

[0233] The structure of the transistor used in the pixel or the driver circuit is not particularly limited. For example, the transistor may be an inverted staggered type transistor or a staggered type transistor. In addition, the transistor may be a top-gate type transistor or a bottom-gate type transistor. The semiconductor material used for the transistor is not particularly limited, and for example, silicon, germanium, silicon carbide, gallium nitride, or the like may be used. Alternatively, an oxide semiconductor containing at least one of indium, gallium, and zinc, such as an In-Ga-Zn-based metal oxide, may be used.

[0234] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in a part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0235] Here, in addition to the transistors provided in the pixels or driver circuits, an oxide semiconductor is preferably used for semiconductor devices such as transistors used in touch sensors, which will be described later. In particular, an oxide semiconductor having a wider band gap than silicon is preferably used. By using an oxide semiconductor having a wider band gap than silicon, the current in the off state of the transistor can be reduced.

[0236] The oxide semiconductor preferably contains at least indium (In) or zinc (Zn), and more preferably contains an oxide represented by In-M-Zn oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf).

[0237] In particular, it is preferable to use, as the semiconductor layer, an oxide semiconductor film which has a plurality of crystal parts whose c-axes are oriented perpendicular to a surface on which the semiconductor layer is formed or a top surface of the semiconductor layer and which has no grain boundaries between adjacent crystal parts.

[0238] By using such a material for the semiconductor layer, fluctuations in electrical characteristics are suppressed, and a highly reliable transistor can be realized.

[0239] In addition, the transistor having the above-mentioned semiconductor layer can hold charge accumulated in a capacitance through the transistor for a long period of time due to its low off-state current. By applying such a transistor to a pixel, it is possible to stop a driver circuit while maintaining the gray level of an image displayed in each display region. As a result, an electronic device with extremely low power consumption can be realized.

[0240] It is preferable to provide an undercoat film in order to stabilize the characteristics of the transistor. The undercoat film can be prepared as a single layer or a multilayer structure using an inorganic insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film. The undercoat film can be formed by a sputtering method, a CVD (Chemical Vapor Deposition) method (such as a plasma CVD method, a thermal CVD method, or a MOCVD (Metal Organic CVD) method), an ALD (Atomic Layer Deposition) method, a coating method, a printing method, or the like. Note that the undercoat film need not be provided if it is not necessary.

[0241] Note that FET 623 indicates one of the transistors formed in the source line driver circuit 601. The driver circuit may be formed of various CMOS circuits, PMOS circuits, or NMOS circuits. In addition, in this embodiment, a driver-integrated type in which a driver circuit is formed on a substrate is shown, but this is not necessarily required, and the driver circuit can also be formed externally instead of on the substrate.

[0242] In addition, the pixel portion 602 is formed by a plurality of pixels including a switching FET 611, a current control FET 612, and a first electrode 613 electrically connected to the drain of the FET 612. However, the present invention is not limited to this, and the pixel portion may be formed by combining three or more FETs and a capacitive element.

[0243] An insulator 614 is formed to cover an end portion of the first electrode 613. Here, the insulator 614 can be formed by using a positive type photosensitive acrylic resin film.

[0244] In order to improve the covering ability of an EL layer or the like to be formed later, a curved surface having a curvature is formed at the upper end or lower end of the insulator 614. For example, when a positive type photosensitive acrylic resin is used as the material of the insulator 614, it is preferable that only the upper end of the insulator 614 has a curved surface having a curvature radius (0.2 μm or more and 3 μm or less). In addition, either a negative type photosensitive resin or a positive type photosensitive resin can be used as the insulator 614.

[0245] An EL layer 616 and a second electrode 617 are formed on the first electrode 613. Here, it is desirable to use a material with a large work function as the material used for the first electrode 613 that functions as an anode. For example, in addition to a single layer film such as an ITO film, an indium tin oxide film containing silicon, an indium oxide film containing 2 wt% to 20 wt% zinc oxide, a titanium nitride film, a chromium film, a tungsten film, a Zn film, or a Pt film, a laminated structure of a titanium nitride film and a film mainly composed of aluminum, or a three-layer structure of a titanium nitride film, a film mainly composed of aluminum, and a titanium nitride film can be used. In addition, when the laminated structure is used, the resistance as a wiring is low, good ohmic contact can be obtained, and the first electrode 613 can function as an anode.

[0246] The EL layer 616 is formed by various methods such as a deposition method using a deposition mask, an inkjet method, a spin coating method, etc. The EL layer 616 includes the configuration described in any one of the embodiments 1 to 4. Other materials constituting the EL layer 616 may be low molecular weight compounds or high molecular weight compounds (including oligomers and dendrimers).

[0247] Furthermore, the second electrode 617 formed on the EL layer 616 and functioning as a cathode is preferably made of a material having a small work function (such as Al, Mg, Li, Ca, or an alloy or compound thereof (MgAg, MgIn, AlLi, etc.)). When light generated in the EL layer 616 is transmitted through the second electrode 617, the second electrode 617 is preferably made of a laminate of a thin metal thin film and a transparent conductive film (ITO, indium oxide containing 2 wt% to 20 wt% zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.).

[0248] Note that a light-emitting device is formed with the first electrode 613, the EL layer 616, and the second electrode 617. The light-emitting device is the light-emitting device described in any one of Embodiments 1 to 4. Note that a pixel portion is formed with a plurality of light-emitting devices, and the light-emitting device in this embodiment may include both the light-emitting device described in any one of Embodiments 1 to 4 and a light-emitting device having a structure other than the above.

[0249] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with a sealant 605, a structure is formed in which a light emitting device 618 is provided in a space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealant 605. The space 607 is filled with a filler, and may be filled with an inert gas (nitrogen, argon, etc.) or a sealant. A recess is formed in the sealing substrate and a desiccant is provided therein to suppress deterioration due to the influence of moisture, which is a preferable configuration.

[0250] It is preferable to use epoxy resin or glass frit for the sealant 605. It is also preferable that these materials are as moisture and oxygen impermeable as possible. In addition to a glass substrate or a quartz substrate, the sealing substrate 604 may be made of a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, or the like.

[0251] Although not shown in Figures 4A and 4B, a protective film may be provided on the second electrode. The protective film may be formed of an organic resin film or an inorganic insulating film. The protective film may be formed so as to cover the exposed portion of the sealant 605. The protective film may be provided so as to cover the surfaces and side surfaces of the pair of substrates, the exposed side surfaces of the sealing layer, the insulating layer, etc.

[0252] The protective film can be made of a material that is difficult for impurities such as water to permeate, and therefore can effectively prevent impurities such as water from diffusing from the outside to the inside.

[0253] The protective film may be made of an oxide, a nitride, a fluoride, a sulfide, a ternary compound, a metal, a polymer, or the like. For example, a material containing aluminum oxide, hafnium oxide, hafnium silicate, lanthanum oxide, silicon oxide, strontium titanate, tantalum oxide, titanium oxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide, cerium oxide, scandium oxide, erbium oxide, vanadium oxide, indium oxide, or the like, or a material containing aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride, gallium nitride, or the like, a nitride containing titanium and aluminum, an oxide containing titanium and aluminum, an oxide containing aluminum and zinc, a sulfide containing manganese and zinc, a sulfide containing cerium and strontium, an oxide containing erbium and aluminum, an oxide containing yttrium and zirconium, or the like may be used.

[0254] The protective film is preferably formed using a film formation method with good step coverage. One such method is the atomic layer deposition (ALD) method. It is preferable to use a material that can be formed using the ALD method for the protective film. By using the ALD method, it is possible to form a dense protective film with reduced defects such as cracks or pinholes, or with a uniform thickness. In addition, it is possible to reduce damage to the processed member when forming the protective film.

[0255] For example, by forming a protective film using the ALD method, it is possible to form a uniform protective film with few defects on a surface having a complex uneven shape or on the top, side and back surfaces of a touch panel.

[0256] In the above manner, a light-emitting device manufactured using the light-emitting device described in any one of Embodiments 1 to 4 can be obtained.

[0257] A light-emitting device with favorable characteristics can be obtained in the light-emitting device in this embodiment because the light-emitting device described in any one of Embodiments 1 to 4 is used. Specifically, the light-emitting device described in any one of Embodiments 1 to 4 has favorable emission efficiency, and therefore the light-emitting device can have low power consumption.

[0258] Fig. 5 shows an example of a full-color light-emitting device in which a light-emitting device that emits white light is formed and a colored layer (color filter) is provided, etc. Fig. 5A shows a substrate 1001, a base insulating film 1002, a gate insulating film 1003, gate electrodes 1006, 1007, 1008, a first interlayer insulating film 1020, a second interlayer insulating film 1021, a peripheral section 1042, a pixel section 1040, a driving circuit section 1041, first electrodes 1024W, 1024R, 1024G, 1024B of the light-emitting device, a partition wall 1025, an EL layer 1028, a second electrode 1029 of the light-emitting device, a sealing substrate 1031, a sealant 1032, etc.

[0259] In FIG. 5A, the colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer 1034B) are provided on a transparent base material 1033. A black matrix 1035 may be further provided. The transparent base material 1033 on which the colored layers and black matrix are provided is aligned and fixed to the substrate 1001. The colored layers and black matrix 1035 are covered with an overcoat layer 1036. In FIG. 5A, there are light-emitting layers from which light does not pass through the colored layers and goes out, and light-emitting layers from which light passes through the colored layers of each color and goes out. The light that does not pass through the colored layers is white, and the light that passes through the colored layers is red, green, and blue, so that an image can be expressed by four color pixels.

[0260] 5B shows an example in which the colored layers (red colored layer 1034R, green colored layer 1034G, and blue colored layer 1034B) are formed between the gate insulating film 1003 and the first interlayer insulating film 1020. In this manner, the colored layers may be provided between the substrate 1001 and the sealing substrate 1031.

[0261] In the light-emitting device described above, the light-emitting device has a structure (bottom emission type) in which light is extracted on the substrate 1001 side on which the FET is formed, but the light-emitting device may have a structure (top emission type) in which light is extracted on the sealing substrate 1031 side. A cross-sectional view of a top emission type light-emitting device is shown in FIG. 6. In this case, a substrate that does not transmit light can be used as the substrate 1001. The process is performed in the same manner as the bottom emission type light-emitting device until a connection electrode that connects the FET and the anode of the light-emitting device is formed. Then, a third interlayer insulating film 1037 is formed to cover the electrode 1022. This insulating film may play a role of planarization. The third interlayer insulating film 1037 can be formed using the same material as the second interlayer insulating film, as well as other known materials.

[0262] The first electrodes 1024W, 1024R, 1024G, and 1024B of the light-emitting device are anodes here, but may be cathodes. In the case of a top-emission type light-emitting device as shown in FIG. 6, the first electrodes are preferably reflective electrodes. The EL layer 1028 has a structure as described as the unit 103 in any one of the first to fourth embodiments, and has an element structure that can emit white light.

[0263] In the top emission structure as shown in FIG. 6, sealing can be performed with a sealing substrate 1031 provided with colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer 1034B). A black matrix 1035 may be provided on the sealing substrate 1031 so as to be located between pixels. The colored layers (red colored layer 1034R, green colored layer 1034G, blue colored layer 1034B) or the black matrix may be covered with an overcoat layer 1036. Note that a substrate having light transmissivity is used as the sealing substrate 1031. In addition, although an example of full color display using four colors, red, green, blue, and white, is shown here, the present invention is not particularly limited, and full color display using four colors, red, yellow, green, and blue, or three colors, red, green, and blue, may be used.

[0264] In a top-emission type light-emitting device, a microcavity structure can be suitably applied. A light-emitting device having a microcavity structure can be obtained by making the first electrode a reflective electrode and the second electrode a semi-transmissive / semi-reflective electrode. At least an EL layer is provided between the reflective electrode and the semi-transmissive / semi-reflective electrode, and at least a light-emitting layer that becomes a light-emitting region is provided.

[0265] The reflectance of the reflective electrode to visible light is 40% to 100%, preferably 70% to 100%, and the resistivity is 1×10 -2 The semi-transmitting and semi-reflective electrode has a visible light reflectance of 20% to 80%, preferably 40% to 70%, and a resistivity of 1×10 -2 It is assumed that the film has a resistance of less than Ωcm.

[0266] Light emitted from a light-emitting layer included in the EL layer is reflected by the reflective electrode and the semi-transmissive and semi-reflective electrode, causing resonance.

[0267] In this light-emitting device, the optical distance between the reflective electrode and the semi-transmissive / semi-reflective electrode can be changed by changing the thickness of the transparent conductive film or the above-mentioned composite material, carrier transport material, etc. This makes it possible to intensify the light of a resonating wavelength between the reflective electrode and the semi-transmissive / semi-reflective electrode and attenuate the light of a non-resonating wavelength.

[0268] In addition, since the light reflected by the reflective electrode and returned (first reflected light) causes significant interference with the light (first incident light) that is directly incident on the semi-transmissive and semi-reflective electrode from the light-emitting layer, it is preferable to adjust the optical distance between the reflective electrode and the light-emitting layer to (2n-1)λ / 4 (where n is a natural number equal to or greater than 1, and λ is the wavelength of the emitted light to be amplified). By adjusting the optical distance, the phase of the first reflected light and the first incident light can be aligned, thereby further amplifying the light emitted from the light-emitting layer.

[0269] In the above configuration, the EL layer may have a structure having multiple light-emitting layers or a structure having a single light-emitting layer. For example, the EL layer may be combined with the above-mentioned tandem light-emitting device configuration, in which multiple EL layers are provided in one light-emitting device with a charge generation layer sandwiched therebetween, and a single or multiple light-emitting layers are formed in each EL layer.

[0270] The microcavity structure makes it possible to increase the emission intensity of a specific wavelength in the front direction, thereby reducing power consumption. In the case of a light-emitting device that displays images using four sub-pixels of red, yellow, green, and blue, in addition to the brightness improvement effect of yellow emission, the microcavity structure that matches the wavelength of each color can be applied to all sub-pixels, resulting in a light-emitting device with good characteristics.

[0271] A light-emitting device with favorable characteristics can be obtained in the light-emitting device in this embodiment because the light-emitting device described in any one of Embodiments 1 to 4 is used. Specifically, the light-emitting device described in any one of Embodiments 1 to 4 has favorable emission efficiency, and therefore the light-emitting device can have low power consumption.

[0272] Up to this point, active matrix type light emitting devices have been described, but from here on, passive matrix type light emitting devices will be described. FIG. 7 shows a passive matrix type light emitting device manufactured by applying the present invention. FIG. 7A is a perspective view showing the light emitting device, and FIG. 7B is a cross-sectional view taken along XY in FIG. 7A. In FIG. 7, an EL layer 955 is provided between an electrode 952 and an electrode 956 on a substrate 951. An end of the electrode 952 is covered with an insulating layer 953. A partition layer 954 is provided on the insulating layer 953. The side walls of the partition layer 954 have an inclination such that the distance between one side wall and the other side wall becomes narrower as the side walls approach the substrate surface. That is, the cross section of the partition layer 954 in the short side direction is trapezoidal, and the bottom side (the side facing the same direction as the surface direction of the insulating layer 953 and in contact with the insulating layer 953) is shorter than the top side (the side facing the same direction as the surface direction of the insulating layer 953 and not in contact with the insulating layer 953). By providing the partition layer 954 in this manner, defects in the light-emitting device due to static electricity or the like can be prevented. In addition, a passive matrix light-emitting device using the light-emitting device described in any one of Embodiments 1 to 4 can be a highly reliable light-emitting device or a light-emitting device with low power consumption.

[0273] The light emitting device described above is capable of individually controlling a large number of minute light emitting devices arranged in a matrix, and is therefore a light emitting device that can be suitably used as a display device for displaying images.

[0274] This embodiment mode can be freely combined with other embodiment modes.

[0275] (Embodiment 6) In this embodiment, an example in which the light-emitting device described in any one of Embodiments 1 to 4 is used as a lighting device will be described with reference to Fig. 8. Fig. 8B is a top view of the lighting device, and Fig. 8A is a cross-sectional view taken along line ef in Fig. 8B.

[0276] In the lighting device in this embodiment, a first electrode 401 is formed over a light-transmitting substrate 400, which is a support. The first electrode 401 corresponds to the electrode 101 in any one of Embodiments 1 to 4. When light is extracted from the first electrode 401 side, the first electrode 401 is formed using a light-transmitting material.

[0277] A pad 412 for supplying a voltage to the second electrode 404 is formed on the substrate 400 .

[0278] An EL layer 403 is formed on the first electrode 401. The EL layer 403 corresponds to the configuration of the unit 103 in any one of Embodiments 1 to 4, or a combination of the unit 103(2), the layer 104, the layer 105, and the intermediate layer 106. For details of these configurations, see the relevant descriptions.

[0279] A second electrode 404 is formed to cover the EL layer 403. The second electrode 404 corresponds to the electrode 102 in any one of Embodiments 1 to 4. When light is extracted from the first electrode 401 side, the second electrode 404 is formed using a material with high reflectivity. The second electrode 404 is connected to a pad 412 to supply a voltage.

[0280] As described above, the lighting device described in this embodiment has a light-emitting device including the first electrode 401, the EL layer 403, and the second electrode 404. Since the light-emitting device has high emission efficiency, the lighting device in this embodiment can have low power consumption.

[0281] The lighting device is completed by adhering and sealing the substrate 400 on which the light-emitting device having the above-mentioned configuration is formed and the sealing substrate 407 using the sealing materials 405 and 406. Either one of the sealing materials 405 and 406 may be used. Also, a desiccant may be mixed into the inner sealing material 406 (not shown in FIG. 8B), which allows it to adsorb moisture and improves reliability.

[0282] Moreover, the pad 412 and a part of the first electrode 401 can be extended outside the sealing materials 405 and 406 to serve as an external input terminal. Also, an IC chip 420 equipped with a converter or the like may be provided thereon.

[0283] As described above, the lighting device described in this embodiment uses the light-emitting device described in any one of Embodiments 1 to 4 as an EL element, and can be a lighting device with low power consumption.

[0284] (Embodiment 7) In this embodiment, an example of an electronic device including a part of the light-emitting device described in any one of Embodiments 1 to 4 will be described. The light-emitting device described in any one of Embodiments 1 to 4 has good emission efficiency and low power consumption. As a result, the electronic device described in this embodiment can be an electronic device having a light-emitting portion with low power consumption.

[0285] Examples of electronic devices to which the light-emitting devices are applied include television sets (also called televisions or television receivers), computer monitors, digital cameras, digital video cameras, digital photo frames, mobile phones (also called mobile phones or mobile phone devices), portable game machines, personal digital assistants, audio playback devices, large game machines such as pachinko machines, etc. Specific examples of these electronic devices are shown below.

[0286] 9A illustrates an example of a television set. In the television set, a display portion 7103 is incorporated in a housing 7101. Here, the housing 7101 is supported by a stand 7105. Images can be displayed by the display portion 7103, and the display portion 7103 has the light-emitting devices described in any one of Embodiments 1 to 4 arranged in a matrix.

[0287] The television device can be operated using an operation switch provided on the housing 7101 or a separate remote control 7110. Using operation keys 7109 provided on the remote control 7110, a channel or volume can be controlled, and an image displayed on the display portion 7103 can be operated. The remote control 7110 may be provided with a display portion 7107 that displays information output from the remote control 7110.

[0288] The television device is configured to include a receiver, a modem, etc. The receiver can receive general television broadcasts, and by connecting to a wired or wireless communication network via a modem, it is also possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0289] FIG. 9B shows a computer, which includes a main body 7201, a housing 7202, a display portion 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, and the like. Note that this computer is manufactured by using the light-emitting devices described in any one of Embodiments 1 to 4 arranged in a matrix for the display portion 7203. The computer in FIG. 9B may have a form as shown in FIG. 9C. The computer in FIG. 9C is provided with a second display portion 7210 instead of the keyboard 7204 and the pointing device 7206. The second display portion 7210 is a touch panel type, and input can be performed by operating the display for input displayed on the second display portion 7210 with a finger or a dedicated pen. The second display portion 7210 can display not only the display for input but also other images. The display portion 7203 may also be a touch panel. The two screens are connected by a hinge, which can prevent the screens from being scratched or damaged during storage or transportation.

[0290] 9D shows an example of a mobile terminal. The mobile phone includes a display portion 7402 incorporated in a housing 7401, operation buttons 7403, an external connection port 7404, a speaker 7405, a microphone 7406, and the like. Note that the mobile phone has the display portion 7402 in which the light-emitting devices described in any one of Embodiments 1 to 4 are arranged in a matrix.

[0291] 9D can be configured so that information can be input by touching the display portion 7402 with a finger or the like. In this case, operations such as making a call or composing an e-mail can be performed by touching the display portion 7402 with a finger or the like.

[0292] The screen of the display unit 7402 has three main modes. The first is a display mode that is mainly for displaying images, the second is an input mode that is mainly for inputting information such as characters, and the third is a display + input mode that combines the display mode and the input mode.

[0293] For example, when making a call or composing an e-mail, the display portion 7402 may be set to a character input mode mainly for inputting characters, and the character input operation may be performed by inputting characters displayed on the screen. In this case, it is preferable to display a keyboard or number buttons on most of the screen of the display portion 7402.

[0294] In addition, by providing a detection device having a sensor for detecting tilt, such as a gyro or an acceleration sensor, inside the mobile terminal, the orientation of the mobile terminal (portrait or landscape) can be determined and the screen display of the display portion 7402 can be automatically switched.

[0295] The screen mode can be switched by touching the display portion 7402 or by operating operation buttons 7403 on the housing 7401. The mode can also be switched depending on the type of image displayed on the display portion 7402. For example, if the image signal to be displayed on the display portion is moving image data, the mode is switched to the display mode, and if it is text data, the mode is switched to the input mode.

[0296] In addition, in the input mode, a signal detected by an optical sensor of the display portion 7402 may be detected, and if there is no input by a touch operation on the display portion 7402 for a certain period of time, the screen mode may be controlled to be switched from the input mode to the display mode.

[0297] The display portion 7402 can also function as an image sensor. For example, personal authentication can be performed by touching the display portion 7402 with a palm or a finger to capture an image of a palm print, a fingerprint, or the like. In addition, finger veins, palm veins, or the like can be captured by using a backlight that emits near-infrared light or a sensing light source that emits near-infrared light for the display portion.

[0298] FIG. 10A is a schematic diagram showing an example of a cleaning robot.

[0299] The cleaning robot 5100 has a display 5101 arranged on the top surface, a plurality of cameras 5102 arranged on the side surface, a brush 5103, and an operation button 5104. Although not shown, the bottom surface of the cleaning robot 5100 is provided with tires, a suction port, and the like. The cleaning robot 5100 also has various sensors such as an infrared sensor, an ultrasonic sensor, an acceleration sensor, a piezoelectric sensor, an optical sensor, and a gyro sensor. The cleaning robot 5100 also has wireless communication means.

[0300] The cleaning robot 5100 can move by itself, detect dirt 5120, and suck up the dirt from a suction port provided on the bottom surface.

[0301] In addition, the cleaning robot 5100 can analyze the image captured by the camera 5102 and determine the presence or absence of obstacles such as walls, furniture, steps, etc. Furthermore, when an object that may become entangled in the brush 5103, such as a wire, is detected by image analysis, the rotation of the brush 5103 can be stopped.

[0302] The remaining battery level, the amount of sucked up dirt, etc. can be displayed on the display 5101. The route traveled by the cleaning robot 5100 may be displayed on the display 5101. The display 5101 may be a touch panel, and an operation button 5104 may be provided on the display 5101.

[0303] The cleaning robot 5100 can communicate with a portable electronic device 5140 such as a smartphone. Images captured by the camera 5102 can be displayed on the portable electronic device 5140. Therefore, the owner of the cleaning robot 5100 can know the state of the room even when he or she is away from home. Also, the display on the display 5101 can be confirmed on the portable electronic device 5140 such as a smartphone.

[0304] The light-emitting device according to one embodiment of the present invention can be used for the display 5101 .

[0305] The robot 2100 shown in FIG. 10B includes a computing device 2110, an illuminance sensor 2101, a microphone 2102, an upper camera 2103, a speaker 2104, a display 2105, a lower camera 2106, an obstacle sensor 2107, and a movement mechanism 2108.

[0306] The microphone 2102 has a function of detecting the user's voice, environmental sounds, etc. The speaker 2104 has a function of emitting sound. The robot 2100 can communicate with the user using the microphone 2102 and the speaker 2104.

[0307] The display 2105 has a function of displaying various information. The robot 2100 can display information desired by the user on the display 2105. The display 2105 may be equipped with a touch panel. The display 2105 may also be a removable information terminal, and by installing it in a fixed position on the robot 2100, charging and data transfer are possible.

[0308] The upper camera 2103 and the lower camera 2106 have a function of capturing images of the surroundings of the robot 2100. In addition, the obstacle sensor 2107 can detect the presence or absence of an obstacle in the moving direction when the robot 2100 moves forward using the moving mechanism 2108. The robot 2100 can recognize the surrounding environment and move safely using the upper camera 2103, the lower camera 2106, and the obstacle sensor 2107. The light-emitting device of one embodiment of the present invention can be used for the display 2105.

[0309] 10C is a diagram showing an example of a goggle-type display. The goggle-type display includes, for example, a housing 5000, a display unit 5001, a speaker 5003, an LED lamp 5004, a connection terminal 5006, a sensor 5007 (including a function for measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared), a microphone 5008, a display unit 5002, a support unit 5012, and an earphone 5013.

[0310] The light-emitting device of one embodiment of the present invention can be used for the display portion 5001 and the display portion 5002 .

[0311] 11 shows an example in which the light-emitting device described in any one of Embodiments 1 to 4 is used in a desk lamp, which is a lighting device. The desk lamp shown in FIG. 11 has a housing 2001 and a light source 2002, and the lighting device described in Embodiment 6 may be used as the light source 2002.

[0312] FIG. 12 shows an example in which the light-emitting device described in any one of Embodiments 1 to 4 is used as an indoor lighting device 3001. Since the light-emitting device described in any one of Embodiments 1 to 4 has high emission efficiency, the lighting device can have low power consumption. Since the light-emitting device described in any one of Embodiments 1 to 4 can be made large in area, the lighting device can be used as a large-area lighting device. Since the light-emitting device described in any one of Embodiments 1 to 4 is thin, the lighting device can be made thin.

[0313] The light-emitting device described in any one of Embodiments 1 to 4 can also be mounted on a windshield or dashboard of an automobile. FIG 13 shows an example in which the light-emitting device described in any one of Embodiments 1 to 4 is used on a windshield or dashboard of an automobile. Display regions 5200 to 5203 are display regions provided using the light-emitting device described in any one of Embodiments 1 to 4.

[0314] A display region 5200 and a display region 5201 are a display device equipped with the light-emitting device described in any one of Embodiments 1 to 4, which is provided on the windshield of an automobile. The light-emitting device described in any one of Embodiments 1 to 4 can be a display device in a so-called see-through state, in which the opposite side can be seen through, by forming the first electrode and the second electrode using light-transmitting electrodes. If the display is in a see-through state, the display device can be installed on the windshield of an automobile without interfering with visibility. When a transistor for driving is provided, a light-transmitting transistor such as an organic transistor made of an organic semiconductor material or a transistor using an oxide semiconductor is preferably used.

[0315] The display area 5202 is a display device provided on a pillar and equipped with the light-emitting device described in any one of Embodiments 1 to 4. By displaying an image from an imaging means provided on the vehicle body in the display area 5202, the view blocked by the pillar can be complemented. Similarly, the display area 5203 provided on the dashboard can complement the view blocked by the vehicle body by displaying an image from an imaging means provided on the outside of the vehicle, thereby compensating for blind spots and improving safety. By displaying an image to complement the invisible parts, safety can be confirmed more naturally and without discomfort.

[0316] The display area 5203 can provide various information by displaying navigation information, speed or revolutions, mileage, remaining fuel, gear status, air conditioning settings, etc. The display items or layout can be changed as appropriate to suit the user's preferences. Note that this information can also be provided in the display areas 5200 to 5202. The display areas 5200 to 5203 can also be used as lighting devices.

[0317] 14A to 14C show a foldable portable information terminal 9310. Fig. 14A shows the portable information terminal 9310 in an unfolded state. Fig. 14B shows the portable information terminal 9310 in a state in the process of changing from one of the unfolded state and the folded state to the other. Fig. 14C shows the portable information terminal 9310 in a folded state. The portable information terminal 9310 has excellent portability in a folded state, and has excellent viewability of the display due to a seamless wide display area in an unfolded state.

[0318] The display panel 9311 is supported by three housings 9315 connected by hinges 9313. Note that the display panel 9311 may be a touch panel (input / output device) equipped with a touch sensor (input device). The display panel 9311 can be reversibly transformed from an unfolded state of the mobile information terminal 9310 to a folded state by bending the two housings 9315 via the hinges 9313. The light-emitting device of one embodiment of the present invention can be used for the display panel 9311.

[0319] Note that the structure described in this embodiment mode can be used by appropriately combining the structures described in any of Embodiment Modes 1 to 4.

[0320] As described above, the light-emitting device including the light-emitting device described in any one of Embodiments 1 to 4 has a very wide range of application, and the light-emitting device can be applied to electronic devices in a variety of fields. By using the light-emitting device described in any one of Embodiments 1 to 4, an electronic device with low power consumption can be obtained.

[0321] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification. EXAMPLES

[0322] In this example, structures, manufacturing methods, and characteristics of light-emitting devices 1 to 5 according to embodiments of the present invention will be described with reference to FIGS.

[0323] 15A and 15B are cross-sectional views illustrating the structure of the fabricated light-emitting device.

[0324] FIG. 16 is a diagram illustrating the current density-luminance characteristics of the light-emitting device 1. As shown in FIG.

[0325] FIG. 17 is a diagram illustrating the luminance-current efficiency characteristics of the light-emitting device 1. As shown in FIG.

[0326] FIG. 18 is a diagram illustrating the voltage-luminance characteristics of the light-emitting device 1. As shown in FIG.

[0327] FIG. 19 is a diagram illustrating the voltage-current characteristics of the light-emitting device 1. As shown in FIG.

[0328] 20 is a diagram illustrating the luminance-external quantum efficiency characteristics of the light-emitting device 1. Assuming that the light distribution characteristics of the light-emitting device are of the Lambertian type, the external quantum efficiency was calculated from the luminance and emission spectrum observed from the front.

[0329] FIG. 21 shows the light-emitting device 1 at 1000 cd / m 2 1 is a diagram illustrating an emission spectrum when light is emitted at a luminance of 1000 nm.

[0330] Figure 22 shows the current at 50mA / cm 2 FIG. 1 is a graph showing the normalized luminance vs. time change characteristics when the light-emitting device 1 is caused to emit light at a constant current density of 50 mA / cm 2 4 also shows the normalized luminance vs. time change characteristics when the comparative light-emitting device is operated at a constant current density of 100 .mu.m.

[0331] FIG. 23 is a diagram illustrating the current density-luminance characteristics of the light-emitting device 2. As shown in FIG.

[0332] FIG. 24 is a diagram illustrating the luminance-current efficiency characteristics of the light-emitting device 2. As shown in FIG.

[0333] FIG. 25 is a diagram illustrating the voltage-luminance characteristics of the light-emitting device 2. As shown in FIG.

[0334] FIG. 26 is a diagram illustrating the voltage-current characteristics of the light-emitting device 2. As shown in FIG.

[0335] 27 is a diagram illustrating the luminance-external quantum efficiency characteristics of the light-emitting device 2. Assuming that the light distribution characteristics of the light-emitting device are of the Lambertian type, the external quantum efficiency was calculated from the luminance and emission spectrum observed from the front.

[0336] FIG. 28 shows the light emitting device 2 at 1000 cd / m 21 is a diagram illustrating an emission spectrum when light is emitted at a luminance of 1000 nm.

[0337] Figure 29 shows the current at 50mA / cm 2 FIG. 1 is a graph showing the normalized luminance vs. time change characteristics when the light-emitting device 2 is caused to emit light at a constant current density of 50 mA / cm 2 4 also shows the normalized luminance vs. time change characteristics when the comparative light-emitting device is operated at a constant current density of 100 .mu.m.

[0338] FIG. 30 is a diagram illustrating the current density-luminance characteristics of the light-emitting device 3. As shown in FIG.

[0339] FIG. 31 is a diagram illustrating the luminance-current efficiency characteristics of the light-emitting device 3. As shown in FIG.

[0340] FIG. 32 is a diagram illustrating the voltage-luminance characteristics of the light-emitting device 3. As shown in FIG.

[0341] FIG. 33 is a diagram illustrating the voltage-current characteristics of the light-emitting device 3. As shown in FIG.

[0342] 34 is a diagram illustrating the luminance-external quantum efficiency characteristics of the light-emitting device 3. Assuming that the light distribution characteristics of the light-emitting device are of the Lambertian type, the external quantum efficiency was calculated from the luminance and emission spectrum observed from the front.

[0343] FIG. 35 shows the light emitting device 3 at 1000 cd / m 2 1 is a diagram illustrating an emission spectrum when light is emitted at a luminance of 1000 nm.

[0344] Figure 36 shows the current at 50mA / cm 2 FIG. 1 is a graph showing the normalized luminance vs. time change characteristics when the light-emitting device 3 is caused to emit light at a constant current density of 50 mA / cm 2 4 also shows the normalized luminance vs. time change characteristics when the comparative light-emitting device is operated at a constant current density of 100 .mu.m.

[0345] FIG. 37 is a graph illustrating the current density-luminance characteristics of the light-emitting device 4. As shown in FIG.

[0346] FIG. 38 is a graph illustrating the luminance-current efficiency characteristics of the light-emitting device 4. As shown in FIG.

[0347] FIG. 39 is a diagram illustrating the voltage-luminance characteristics of the light-emitting device 4. As shown in FIG.

[0348] FIG. 40 is a diagram illustrating the voltage-current characteristics of the light-emitting device 4. As shown in FIG.

[0349] 41 is a diagram illustrating the luminance-external quantum efficiency characteristics of the light-emitting device 4. Assuming that the light distribution characteristics of the light-emitting device are of the Lambertian type, the external quantum efficiency was calculated from the luminance and emission spectrum observed from the front.

[0350] FIG. 42 shows the light emitting device 4 at 1000 cd / m 2 1 is a diagram illustrating an emission spectrum when light is emitted at a luminance of 1000 nm.

[0351] Figure 43 shows the current at 50mA / cm 2 FIG. 1 is a graph showing the normalized luminance vs. time change characteristics when the light-emitting device 4 is caused to emit light at a constant current density of 50 mA / cm 2 4 also shows the normalized luminance vs. time change characteristics when the comparative light-emitting device is operated at a constant current density of 100 .mu.m.

[0352] 44A and 44B are cross-sectional views illustrating the structure of the fabricated light-emitting device.

[0353] FIG. 45 is a diagram illustrating the current density-luminance characteristics of the light-emitting device 5. As shown in FIG.

[0354] FIG. 46 is a diagram illustrating the luminance-current efficiency characteristics of the light-emitting device 5. As shown in FIG.

[0355] FIG. 47 is a diagram illustrating the voltage-luminance characteristics of the light-emitting device 5. As shown in FIG.

[0356] FIG. 48 is a diagram illustrating the voltage-current characteristics of the light-emitting device 5. As shown in FIG.

[0357] 49 is a diagram illustrating the luminance-external quantum efficiency characteristics of the light-emitting device 5. Assuming that the light distribution characteristics of the light-emitting device are of the Lambertian type, the external quantum efficiency was calculated from the luminance and emission spectrum observed from the front.

[0358] FIG. 50 shows the light emitting device 5 at 1000 cd / m 2 1 is a diagram illustrating an emission spectrum when light is emitted at a luminance of 1000 nm.

[0359] Figure 51 shows the current at 50mA / cm 2 FIG. 1 is a graph showing the normalized luminance vs. time change characteristics when the light-emitting device 5 is caused to emit light at a constant current density of 50 mA / cm 2 4 also shows the normalized luminance vs. time change characteristics when the comparative light-emitting device is operated at a constant current density of 100 .mu.m.

[0360] <Light emitting device 1> The light-emitting device 1 fabricated in this example has a similar configuration to that of the light-emitting device 150 (see FIG. 15A). The light-emitting device 150 has an electrode 101, an electrode 102, a unit 103, and a layer 104, and the electrode 102 has an area overlapping with the electrode 101.

[0361] The unit 103 comprises a region sandwiched between the electrodes 101 and 102 , and the unit 103 comprises a layer 111 and a layer 112 .

[0362] The layer 111 has a region in which the layer 112 is sandwiched between the electrode 101 and the layer 111, and the layer 111 contains a light-emitting material EM. In the light-emitting device 1, 3,10PCA2Nbf(IV)-02 was used as the light-emitting material EM.

[0363] The layer 104 has a region sandwiched between the layer 112 and the electrode 101, includes a material AM having acceptor properties and a material HT1, and has a region 104A and a region 104B. In the light-emitting device 1, an electron acceptor material (abbreviation: OCHD-001) was used as the material AM having acceptor properties. Also, BBABnf was used as the material HT1.

[0364] Region 104A includes a region sandwiched between region 104B and electrode 101, and region 104A includes a material AM having acceptor properties at a concentration C1, and region 104B includes a material AM having acceptor properties at a concentration C2. Note that concentration C2 is higher than zero and lower than concentration C1. Note that in light-emitting device 1, region 104A was formed using only OCHD-001, and region 104B was formed using BBABnf and OCHD-001.

[0365] The layer 112 includes a region 112A and a region 112B, the region 112B includes a region sandwiched between the layer 111 and the region 112A, and the region 112B includes a material HT2. In the light-emitting device 1, PCzN2 was used as the material HT2.

[0366] The material HT1 had a first HOMO level, and the first HOMO level was −5.7 eV or more and −5.4 eV or less. According to a cyclic voltammetry (CV) measurement, the HOMO level of BBABnf was −5.56 eV.

[0367] The material HT2 has a second HOMO level, which is in the range of -0.2 eV to 0 eV with respect to the first HOMO level. According to CV measurements, the HOMO level of PCzN2 is -5.71 eV.

[0368] The layer 113 has a region sandwiched between the electrode 102 and the layer 111, and the layer 113 includes the material OMC, which is an organic complex of an alkali metal or an organic complex of an alkaline earth metal. In the light-emitting device 1, Liq is used as the material OMC.

[0369] The layer 111 includes a host material HOST, and the host material HOST has a first LUMO level. In the light-emitting device 1, αN-βNPAnth was used as the host material HOST. According to a CV measurement, the LUMO level of αN-βNPAnth was −2.74 eV.

[0370] Unit 103 comprises layer 113, layer 113 comprises region 113A and region 113B, region 113A comprises a region sandwiched between region 113B and layer 111.

[0371] The region 113A includes a material ET, and the region 113B includes a material OMC. The material ET has a second LUMO level. In the light-emitting device 1, ZADN is used as the material ET. According to a CV measurement, the LUMO level of ZADN is −2.87 eV. Therefore, the second LUMO level is in the range of −0.4 eV to −0.11 eV with respect to the first LUMO level.

[0372] Moreover, the region 104 A contacts the electrode 101 .

[0373] <Configuration of Light-Emitting Device 1> The configuration of the light-emitting device 1 is shown in Table 1. The structural formulas of the materials used in the light-emitting device described in this example are shown below.

[0374] [Table 1]

[0375] [ka]

[0376] 《How to calculate the HOMO and LUMO levels of a material》 The HOMO and LUMO levels of the materials were calculated based on cyclic voltammetry (CV) measurements. The calculation method is shown below.

[0377] The measurement device used was an electrochemical analyzer (manufactured by BAS Co., Ltd., model number: ALS model 600A or 600C). The solution used for CV measurement was prepared by dissolving the supporting electrolyte tetra-n-butylammonium perchlorate (n-Bu4NClO4) (manufactured by Tokyo Chemical Industry Co., Ltd., catalog number: T0836) in dehydrated dimethylformamide (DMF) (manufactured by Aldrich Co., Ltd., 99.8%, catalog number: 22705-6) to a concentration of 100 mmol / L, and further dissolving the measurement target to a concentration of 2 mmol / L.

[0378] The working electrode was a platinum electrode (PTE platinum electrode, manufactured by BAS Co., Ltd.), the auxiliary electrode was a platinum electrode (Pt counter electrode (5 cm) for VC-3, manufactured by BAS Co., Ltd.), and the reference electrode was an Ag / Ag + An electrode (RE7 non-aqueous solvent reference electrode, manufactured by BAS Co., Ltd.) was used. The measurements were carried out at room temperature (20 to 25°C).

[0379] The scan speed during CV measurement was standardized to 0.1 V / sec, and the oxidation potential Ea [V] and reduction potential Ec [V] relative to the reference electrode were measured. Ea was the midpoint potential of the oxidation-reduction wave, and Ec was the midpoint potential of the reduction-oxidation wave. Here, since the potential energy of the reference electrode used in this embodiment relative to the vacuum level is known to be -4.94 [eV], the HOMO level and the LUMO level can be calculated from the formulas HOMO level [eV] = -4.94-Ea and LUMO level [eV] = -4.94-Ec, respectively.

[0380] <<Method of manufacturing light-emitting device 1>> The light-emitting device 1 described in this example was fabricated using a method having the following steps.

[0381] [First step] In the first step, the electrode 101 was formed. Specifically, the electrode 101 was formed by a sputtering method using indium oxide-tin oxide (abbreviation: ITSO) containing silicon or silicon oxide as a target.

[0382] The electrode 101 includes ITSO, has a thickness of 70 nm, and is 4 mm 2 It has an area of ​​(2mm x 2mm).

[0383] Next, the base material on which the electrode 101 was formed was washed with water, baked at 200° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds. -4 The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and vacuum baking was performed at 170° C. for 30 minutes in a heating chamber in the vacuum deposition apparatus. Thereafter, the substrate was allowed to cool for about 30 minutes.

[0384] [Second step] In the second step, the region 104A was formed on the electrode 101. -4 After reducing the pressure to 100 Pa, the materials were evaporated using a resistive heating method.

[0385] Note that region 104A contains OCHD-001 and has a thickness of 1 nm.

[0386] [Third step] In the third step, the region 104B was formed on the region 104A by co-evaporation of materials using a resistive heating method.

[0387] The region 104B contains BBABnf and OCHD-001 in a weight ratio of BBABnf:OCHD-001=1:0.10, and has a thickness of 10 nm.

[0388] [Fourth step] In the fourth step, the region 112A was formed on the region 104B by evaporating material using a resistive heating method.

[0389] It should be noted that region 112A includes BBABnf and has a thickness of 20 nm.

[0390] [5th ​​step] In the fifth step, the region 112B was formed on the region 112A. Specifically, a material was evaporated by using a resistive heating method.

[0391] The region 112B includes 3,3'-(naphthalene-1,4-diyl)bis(9-phenyl-9H-carbazole) (abbreviation: PCzN2) and has a thickness of 10 nm.

[0392] [Sixth step] In the sixth step, a layer 111 was formed on the region 112B. Specifically, materials were co-evaporated using a resistive heating method.

[0393] The layer 111 contains αN-βNPAnth and 3,10PCA2Nbf(IV)-02 in a weight ratio of αN-βNPAnth:3,10PCA2Nbf(IV)-02=1:0.015, and has a thickness of 25 nm.

[0394] [Seventh step] In the seventh step, a region 113A was formed on the layer 111. Specifically, materials were co-evaporated using a resistance heating method.

[0395] The region 113A contains 2-{4-[9,10-di(naphthalen-2-yl)-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviation: ZADN) and Liq in a weight ratio of ZADN:Liq=0.3:1, and has a thickness of 17.5 nm.

[0396] [8th step] In the eighth step, the region 113B was formed on the region 113A. Specifically, materials were co-evaporated using a resistance heating method.

[0397] The region 113B contains ZADN and Liq in a weight ratio of ZADN:Liq=1:0.3, and has a thickness of 17.5 nm.

[0398] [9th step] In the ninth step, the electrode 102 was formed on the region 113B. Specifically, a material was evaporated by using a resistance heating method.

[0399] The electrode 102 contains Al and has a thickness of 120 nm.

[0400] <Operation characteristics of light-emitting device 1> When power was applied, the light emitting device 1 emitted light EL1 (see FIG. 15A). The operating characteristics of the light emitting device 1 were measured (see FIGS. 16 to 22). The measurements were carried out at room temperature.

[0401] Light-emitting device 1 with a luminance of 1000 cd / m 2 Table 2 shows the main initial characteristics when the device was caused to emit light at about this temperature (initial characteristics of other light-emitting devices are also shown in Table 2, and their configurations will be described later).

[0402] [Table 2]

[0403] The light-emitting device 1 was found to exhibit good characteristics. For example, 2 The voltage required to emit light at a luminance of 50 mA / cm was lower than that of the comparative light-emitting device 1A. 2 When the light-emitting device 1 was allowed to continue emitting light at a constant current density of 1000 mA, the decrease in luminance was smaller than that of the comparative light-emitting device 1A (see FIG. 22). Specifically, the decrease in luminance was improved after about 525 hours. For example, at about 940 hours, the luminance characteristic, which had decreased to 92.1% of the initial luminance, was improved to 93.6% of the initial luminance. This made it possible to improve reliability while suppressing the driving voltage. As a result, it was possible to provide a novel light-emitting device that is excellent in convenience, usefulness, and reliability.

[0404] Unlike comparative light-emitting device 1A, light-emitting device 1 has not only a region in layer 104 containing BBABnf and OCHD-001 in a weight ratio of BBABnf:OCHD-001=1:0.10, but also a region 104A containing OCHD-001 at a high concentration.

[0405] <Light Emitting Device 2> The configuration of the light-emitting device 2 is shown in Table 3. In the light-emitting device 2 fabricated and described in this example, the concentration of the material AM having acceptor properties contained in the region 104B is lower than that of the light-emitting device 1. Specifically, the region 104B of the light-emitting device 1 contains OCHD-001 at a concentration of 0.10 relative to BBABnf, and the region 104B of the light-emitting device 2 contains OCHD-001 at a concentration of 0.03 relative to BBABnf. Here, the different parts will be described in detail, and the above description will be used for parts using a similar configuration.

[0406] [Table 3]

[0407] <<Method of manufacturing light-emitting device 2>> Light-emitting device 2 was fabricated using a method having the following steps.

[0408] The method for producing light-emitting device 2 differs from the method for producing light-emitting device 1 in the step of forming region 104B. Specifically, the method for producing light-emitting device 2 differs from the method for producing light-emitting device 1 in that OCHD-001 is co-deposited at a weight ratio of 0.03 with respect to BBABnf. Here, the differences will be described in detail, and the above description will be used for the parts in which similar methods are used.

[0409] [Third step] In the third step, the region 104B was formed on the region 104A by co-evaporation of materials using a resistive heating method.

[0410] The region 104B contains BBABnf and OCHD-001 in a weight ratio of BBABnf:OCHD-001=1:0.03, and has a thickness of 10 nm.

[0411] <Operation characteristics of light-emitting device 2> The operating characteristics of the light emitting device 2 were measured (see FIGS. 23 to 29). The measurements were carried out at room temperature.

[0412] Light-emitting device 2 with a luminance of 1000 cd / m 2 Table 2 shows the main initial characteristics when the device is made to emit light at about this temperature.

[0413] The light-emitting device 2 was found to exhibit good characteristics. For example, 2 The voltage required to emit light with a luminance of 50 mA / cm was lower than that of the comparative light-emitting device 1B. 2 When the light-emitting device 2 was allowed to continue emitting light at a constant current density of 1000 mA, the decrease in luminance was smaller than that of the comparative light-emitting device 1B (see FIG. 29). Specifically, the decrease in luminance was improved after about 610 hours. For example, the characteristic of the luminance decreasing to 94.4% of the initial luminance at about 740 hours was improved to 95.3% of the initial luminance. This enabled the reliability to be improved while suppressing the driving voltage. As a result, a novel light-emitting device excellent in convenience, usefulness, and reliability could be provided.

[0414] Unlike the comparative light-emitting device 1B, the light-emitting device 2 includes not only a region in which the layer 104 includes BBABnf and OCHD-001, but also a region 104A that includes OCHD-001 at a high concentration. The region 104B of the light-emitting device 2 includes BBABnf and OCHD-001 in a ratio of BBABnf:OCHD-001=1:0.03 (weight ratio), and the layer 104 of the comparative light-emitting device 1B includes BBABnf and OCHD-001 in a ratio of BBABnf:OCHD-001=1:0.10 (weight ratio).

[0415] <Light emitting device 3> The configuration of the light-emitting device 3 is shown in Table 4. In the light-emitting device 3 fabricated and described in this example, the concentration of the material AM having acceptor properties contained in the region 104B is lower than that of the light-emitting device 2. Specifically, the region 104B of the light-emitting device 2 contains OCHD-001 at a concentration of 0.03 relative to BBABnf, and the region 104B of the light-emitting device 3 contains OCHD-001 at a concentration of 0.01 relative to BBABnf. Here, the different parts will be described in detail, and the above description will be used for parts using a similar configuration.

[0416] [Table 4]

[0417] <<Method of manufacturing light-emitting device 3>> Light-emitting device 3 was fabricated using a method having the following steps.

[0418] The method for producing light-emitting device 3 differs from the method for producing light-emitting device 1 in the step of forming region 104B. Specifically, the method for producing light-emitting device 3 differs from the method for producing light-emitting device 1 in that OCHD-001 is co-deposited at a weight ratio of 0.01 to BBABnf. Here, the differences will be described in detail, and the above description will be used for the parts where a similar method is used.

[0419] [Third step] In the third step, the region 104B was formed on the region 104A by co-evaporation of materials using a resistive heating method.

[0420] The region 104B contains BBABnf and OCHD-001 in a weight ratio of BBABnf:OCHD-001=1:0.01, and has a thickness of 10 nm.

[0421] <Operation characteristics of light-emitting device 3> The operating characteristics of the light emitting device 3 were measured (see FIGS. 30 to 36). The measurements were carried out at room temperature.

[0422] Light-emitting device 3 with a luminance of 1000 cd / m 2 Table 2 shows the main initial characteristics when the device is made to emit light at about this temperature.

[0423] The light-emitting device 3 was found to exhibit good characteristics. For example, 2 The voltage required to emit light with a luminance of 50 mA / cm was lower than that of the comparative light-emitting device 1B. 2 When the light-emitting device 3 was allowed to continue emitting light at a constant current density of 1000 s, the decrease in luminance was smaller than that of the comparative light-emitting device 1B (see FIG. 36). Specifically, the decrease in luminance was improved after about 570 hours. For example, the characteristic of the luminance decreasing to 94.5% of the initial luminance at about 740 hours was improved to 95.5% of the initial luminance. This enabled the reliability to be improved while suppressing the driving voltage. As a result, a novel light-emitting device excellent in convenience, usefulness, and reliability could be provided.

[0424] Unlike the comparative light-emitting device 1B, the light-emitting device 3 includes not only a region in which the layer 104 includes BBABnf and OCHD-001, but also a region 104A that includes OCHD-001 at a high concentration. The region 104B of the light-emitting device 3 includes BBABnf and OCHD-001 in a ratio of BBABnf:OCHD-001=1:0.01 (weight ratio), and the layer 104 of the comparative light-emitting device 1B includes BBABnf and OCHD-001 in a ratio of BBABnf:OCHD-001=1:0.10 (weight ratio).

[0425] <Light Emitting Device 4> The light-emitting device 4 fabricated in this example has a similar configuration to that of the light-emitting device 150 (see FIG. 15B). The light-emitting device 150 has an electrode 101, an electrode 102, a unit 103, a layer 104, and a unit 103(12), and the electrode 102 has a region overlapping with the electrode 101. The light-emitting device 150 also has a layer 105 and an intermediate layer 106, and the intermediate layer 106 has a layer 104 and a layer 106A.

[0426] The unit 103 comprises a region sandwiched between the electrodes 101 and 102 , and the unit 103 comprises a layer 111 and a layer 112 .

[0427] The layer 111 has a region in which the layer 112 is sandwiched between the electrode 101 and the layer 111, and the layer 111 includes a light-emitting material EM. In the light-emitting device 4, bis[2-(2-pyridinyl-κN2)phenyl-κC][2-(5-phenyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(ppy)2(4dppy)) is used as the light-emitting material EM.

[0428] The layer 104 has a region sandwiched between the layer 112 and the electrode 101, includes a material AM having acceptor properties and a material HT1, and has a region 104A and a region 104B. In the light-emitting device 4, OCHD-001 was used as the material AM having acceptor properties. Furthermore, PCBBiF was used as the material HT1.

[0429] Region 104A includes a region sandwiched between region 104B and electrode 101, and region 104A contains a material AM having acceptor properties at a concentration C1, and region 104B contains a material AM having acceptor properties at a concentration C2. Note that concentration C2 is higher than zero and lower than concentration C1. Note that in light-emitting device 4, region 104A was formed using only OCHD-001, and region 104B was formed using PCBBiF and OCHD-001.

[0430] <<Configuration of Light-Emitting Device 4>> The configuration of the light-emitting device 4 is shown in Table 5. The structural formulas of the materials used in the light-emitting device described in this example are shown below.

[0431] [Table 5]

[0432] [ka]

[0433] <<How to make light-emitting device 4>> Light-emitting device 4 was fabricated using a method having the following steps.

[0434] [First step] In the first step, the electrode 101 was formed. Specifically, the electrode 101 was formed by a sputtering method using indium oxide-tin oxide (ITSO) containing silicon or silicon oxide as a target.

[0435] The electrode 101 includes ITSO, has a thickness of 70 nm, and is 4 mm 2 It has an area of ​​(2mm x 2mm).

[0436] Next, the base material on which the electrode 101 was formed was washed with water, baked at 200° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds. -4 The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and vacuum baking was performed at 170° C. for 30 minutes in a heating chamber in the vacuum deposition apparatus. Thereafter, the substrate was allowed to cool for about 30 minutes.

[0437] [Second step] In the second step, a layer 104 (12) was formed on the electrode 101. Specifically, the material was evaporated using a resistive heating method.

[0438] In addition, layer 104(12) includes OCHD-001 and has a thickness of 1 nm.

[0439] [Third step] In the third step, region 112A(12) was formed on layer 104(12). Specifically, material was evaporated using a resistive heating method.

[0440] The region 112A(12) includes BBABnf and has a thickness of 20 nm.

[0441] [Fourth step] In the fourth step, the region 112B(12) was formed on the region 112A(12). Specifically, a material was evaporated by using a resistive heating method.

[0442] Note that region 112B(12) contains PCzN2 and has a thickness of 10 nm.

[0443] [5th ​​step] In the fifth step, a layer 111(12) was formed on the region 112B(12) by co-evaporation of materials using a resistance heating method.

[0444] The layer 111(12) contains cgDBCzPA and 3,10PCA2Nbf(IV)-02 in a weight ratio of cgDBCzPA:3,10PCA2Nbf(IV)-02 = 1:0.015, and has a thickness of 25 nm.

[0445] [Sixth step] In the sixth step, the region 113A(12) was formed on the layer 111(12). Specifically, a material was evaporated by using a resistive heating method.

[0446] In addition, the region 113A(12) contains cgDBCzPA and has a thickness of 10 nm.

[0447] [Seventh step] In the seventh step, the region 113B(12) was formed on the region 113A(12). Specifically, a material was evaporated by using a resistance heating method.

[0448] The region 113B(12) contains 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) and has a thickness of 10 nm.

[0449] [8th step] In the eighth step, a layer 105(12) was formed on the region 113B(12) by evaporating a material using a resistive heating method.

[0450] The layer 105(12) contains lithium oxide (abbreviation: Li2O) and has a thickness of 0.1 nm.

[0451] [9th step] In the ninth step, a layer 106A was formed on the layer 105(12). Specifically, a material was evaporated by using a resistive heating method.

[0452] It should be noted that layer 106A contains CuPc and has a thickness of 2 nm.

[0453] [10th step] In the tenth step, region 104A was formed on layer 106A by evaporating material using a resistive heating method.

[0454] Note that region 104A contains OCHD-001 and has a thickness of 1 nm.

[0455] [11th step] In an eleventh step, the region 104B was formed on the region 104A by co-evaporation of materials using a resistance heating method.

[0456] Region 104B contains PCBBiF and OCHD-001 in a ratio of PCBBiF:OCHD-001=1:0.1 (weight ratio) and has a thickness of 10 nm.

[0457] [12th step] In a twelfth step, a layer 112 was formed on the region 104B. Specifically, a material was evaporated using a resistive heating method.

[0458] Note that layer 112 includes PCBBiF and has a thickness of 15 nm.

[0459] [13th step] In a thirteenth step, a layer 111 was formed on the layer 112. Specifically, materials were co-evaporated using a resistance heating method.

[0460] The layer 111 contains 8-(1,1'-biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), and Ir(ppy)2(4dppy) in a weight ratio of 8BP-4mDBtPBfpm:βNCCP:Ir(ppy)2(4dppy) = 0.6:0.4:0.1, and has a thickness of 40 nm.

[0461] [14th step] In a fourteenth step, a region 113A was formed on the layer 111. Specifically, a material was evaporated by using a resistive heating method.

[0462] The region 113A contains 9,9'-(pyrimidine-4,6-diyldi-3,1-phenylene)bis(9H-carbazole) (abbreviation: 4,6mCzP2Pm) and has a thickness of 20 nm.

[0463] [15th step] In the fifteenth step, the region 113B was formed on the region 113A. Specifically, a material was evaporated by using a resistance heating method.

[0464] Note that region 113B contains NBPhen and has a thickness of 15 nm.

[0465] [16th step] In the sixteenth step, the layer 105 was formed on the region 113B. Specifically, the material was evaporated by using a resistive heating method.

[0466] The layer 105 contains lithium fluoride (abbreviation: LiF) and has a thickness of 1 nm.

[0467] [17th step] In the seventeenth step, the electrode 102 was formed on the layer 105. Specifically, the material was evaporated using a resistive heating method.

[0468] The electrode 102 contains Al and has a thickness of 120 nm.

[0469] <<Operation characteristics of light-emitting device 4>> When power was applied, the light emitting device 4 emitted light EL1 and light EL12 (see FIG. 15B). The operating characteristics of the light emitting device 4 were measured (see FIGS. 37 to 43). The measurements were performed at room temperature.

[0470] The main initial characteristics of the light-emitting device 4 are shown in Table 2.

[0471] The light-emitting device 4 was found to exhibit good characteristics. For example, 2 The voltage required to emit light with a luminance of 50 mA / cm was lower than those of Comparative Light-Emitting Device 2 and Comparative Light-Emitting Device 3. 2 When the light-emitting device 4 was allowed to continue emitting light at a constant current density of 1000 mA, the decrease in luminance was smaller than that of the comparative light-emitting device 2 (see FIG. 43). For example, the characteristic of the luminance decreasing to 90.2% of the initial luminance after about 185 hours was improved to 92.6% of the initial luminance. This enabled the reliability to be improved while suppressing the driving voltage. As a result, a novel light-emitting device excellent in convenience, usefulness, and reliability could be provided.

[0472] The light-emitting device 4 is different from the comparative light-emitting device 2 in that the layer 104 includes not only a region containing PCBBiF and OCHD-001 in a ratio of PCBBiF:OCHD-001=1:0.10 (weight ratio) but also a region 104A containing OCHD-001 at a high concentration. This allows electrons to be supplied to the anode side and holes to the cathode side at a low voltage. The light-emitting device 4 is different from the comparative light-emitting device 3 in that the layer 104 includes not only a region containing OCHD-001 in a high concentration but also a region 104B containing PCBBiF and OCHD-001 in a ratio of PCBBiF:OCHD-001=1:0.10 (weight ratio). This allows the thickness of the layer 104 to be increased. Alternatively, the layer 104 can be used to cover unevenness caused by stacking multiple layers. Alternatively, the layer 104 can be used to alleviate unevenness at the interface caused by the unevenness. Alternatively, the increase in operating voltage caused by unevenness at the interface can be prevented. Alternatively, electrons could be supplied to the anode side and holes could be supplied to the cathode side at a low voltage. The total thickness of region 104B and layer 112 of light-emitting device 4 was equal to the thickness of layer 112 of comparative light-emitting device 3.

[0473] <Light Emitting Device 5> The light-emitting device 5 fabricated in this example has a similar configuration to that of the light-emitting device 150 (see FIG. 44A). The light-emitting device 150 has an electrode 101, an electrode 102, a unit 103 (12), and a layer 104 (12), and the electrode 102 has an area overlapping with the electrode 101. The light-emitting device 150 also has a unit 103, an intermediate layer 106, and a layer 105.

[0474] Unit 103(12) comprises a region sandwiched between electrode 101 and electrode 102, and unit 103(12) comprises layer 111(12) and layer 112(12).

[0475] The layer 111(12) has a region in which the layer 112(12) is sandwiched between the electrode 101 and the layer 111(12), and the layer 111(12) contains a light-emitting material EM. In the light-emitting device 5, 3,10PCA2Nbf(IV)-02 was used as the light-emitting material EM.

[0476] The layer 104(12) has a region sandwiched between the layer 112(12) and the electrode 101, the layer 104(12) includes a material AM having acceptor properties and a material HT1, and the layer 104(12) has a region 104A(12) and a region 104B(12). In the light-emitting device 5, OCHD-001 was used as the material AM having acceptor properties. BBABnf was used as the material HT1.

[0477] Region 104A(12) comprises a region sandwiched between region 104B(12) and electrode 101, region 104A(12) contains material AM having acceptor properties at a concentration C1, and region 104B(12) contains material AM having acceptor properties at a concentration C2. Note that concentration C2 is higher than zero and lower than concentration C1. Note that in light-emitting device 5, region 104A(12) was formed using only OCHD-001, and region 104B(B) was formed using BBABnf and OCHD-001.

[0478] The unit 103 comprises a layer 113 , the layer 113 comprises a region 113 A and a sixth region 113 B, the region 113 A comprises a region sandwiched between the region 113 B and the layer 111 .

[0479] The intermediate layer 106 comprises the units 103 ( 12 ) and the area sandwiched between the units 103 .

[0480] <<Configuration of Light-Emitting Device 5>> The configuration of light-emitting device 5 is shown in Table 6. The structural formulas of the materials used in the light-emitting device described in this example are shown in Example 1.

[0481] [Table 6]

[0482] <<Method of manufacturing light-emitting device 5>> A method having the following steps was used to fabricate the light-emitting device 5 described in this example.

[0483] [First step] In the first step, the reflective film REF was formed by sputtering using an alloy (abbreviated as APC) containing silver (Ag), palladium (Pd) and copper (Cu) as a target.

[0484] The reflective film REF includes APC and has a thickness of 100 nm.

[0485] [Second step] In the second step, the electrode 101 was formed on the reflective film REF. Specifically, it was formed by a sputtering method using ITSO.

[0486] The electrode 101 includes ITSO, has a thickness of 85 nm, and is 4 mm 2 It has an area of ​​(2mm x 2mm).

[0487] Next, the base material on which the electrode 101 was formed was washed with water, baked at 200° C. for 1 hour, and then subjected to UV ozone treatment for 370 seconds. -4 The substrate was introduced into a vacuum deposition apparatus whose inside had been reduced in pressure to about Pa, and vacuum baking was performed at 170° C. for 30 minutes in a heating chamber in the vacuum deposition apparatus. Thereafter, the substrate was allowed to cool for about 30 minutes.

[0488] [Third step] In the third step, the region 104A(12) was formed on the electrode 101. Specifically, a material was evaporated by using a resistance heating method.

[0489] Note that region 104A(12) contains OCHD-001 and has a thickness of 1 nm.

[0490] [Fourth step] In the fourth step, the region 104B(12) was formed on the region 104A(12) by co-evaporation of materials using a resistance heating method.

[0491] The region 104B(12) contains BBABnf and OCHD-001 in a weight ratio of BBABnf:OCHD-001=1:0.03, and has a thickness of 10 nm.

[0492] [5th ​​step] In the fifth step, the region 112A(12) was formed on the region 104B(12). Specifically, a material was evaporated by using a resistive heating method.

[0493] In addition, the region 112A(12) includes BBABnf and has a thickness of 45 nm.

[0494] [Sixth step] In the sixth step, the region 112B(12) was formed on the region 112A(12). Specifically, a material was evaporated by using a resistive heating method.

[0495] Note that region 112B(12) contains PCzN2 and has a thickness of 10 nm.

[0496] [Seventh step] In the seventh step, a layer 111(12) was formed on the region 112B(12) by co-evaporation of materials using a resistance heating method.

[0497] The layer 111(12) contains αN-βNPAnth and 3,10PCA2Nbf(IV)-02 in a weight ratio of αN-βNPAnth:3,10PCA2Nbf(IV)-02 = 1:0.015, and has a thickness of 25 nm.

[0498] [8th step] In the eighth step, a region 113A(12) was formed on the layer 111(12). Specifically, a material was evaporated by using a resistive heating method.

[0499] The region 113A(12) contains 2mDBTBPDBq-II and has a thickness of 15 nm.

[0500] [9th step] In the ninth step, the region 113B(12) was formed on the region 113A(12). Specifically, a material was evaporated by using a resistance heating method.

[0501] In addition, the region 113B(12) contains NBPhen and has a thickness of 10 nm.

[0502] [10th step] In the tenth step, layer 105(12) was formed on region 113B(12) by evaporating material using a resistive heating method.

[0503] In addition, the layer 105(12) contains Li2O and has a thickness of 0.05 nm.

[0504] [11th step] In the eleventh step, a layer 106A was formed on the layer 105(12). Specifically, a material was evaporated by using a resistive heating method.

[0505] Note that layer 106A contains CuPc and has a thickness of 2 nm.

[0506] [12th step] In a twelfth step, layer 104 was formed on layer 106A by evaporating the material using a resistive heating method.

[0507] Note that layer 104 comprises OCHD-001 and has a thickness of 2.5 nm.

[0508] [13th step] In a thirteenth step, a layer 112 was formed on the layer 104. Specifically, the material was evaporated using a resistive heating method.

[0509] Note that layer 112 includes PCBBiF and has a thickness of 25 nm.

[0510] [14th step] In a fourteenth step, a layer 111 was formed on the layer 112. Specifically, materials were co-evaporated using a resistance heating method.

[0511] The layer 111 contains 8BP-4mDBtPBfpm, βNCCP, and Ir(ppy)2(4dppy) in a weight ratio of 8BP-4mDBtPBfpm:βNCCP:Ir(ppy)2(4dppy)=0.5:0.5:0.1, and has a thickness of 40 nm.

[0512] [15th step] In the fifteenth step, a region 113A was formed on the layer 111. Specifically, a material was evaporated using a resistive heating method.

[0513] Note that region 113A contains 4,6mCzP2Pm and has a thickness of 25 nm.

[0514] [16th step] In the sixteenth step, the region 113B was formed on the region 113A. Specifically, a material was evaporated by using a resistive heating method.

[0515] Note that region 113B contains NBPhen and has a thickness of 15 nm.

[0516] [17th step] In the seventeenth step, layer 105 was formed on region 113B by evaporating material using a resistive heating method.

[0517] The layer 105 contains LiF and has a thickness of 1 nm.

[0518] [18th step] In the eighteenth step, the electrode 102A was formed on the layer 105. Specifically, materials were co-evaporated using a resistance heating method.

[0519] The electrode 102A contains Ag and Mg at a volume ratio of Ag:Mg=1:0.1, and has a thickness of 15 nm.

[0520] [Step 19] In a nineteenth step, the electrode 102B was formed on the electrode 102A. Specifically, the electrode 102B was formed by a sputtering method using indium oxide-tin oxide (abbreviation: ITO) as a target.

[0521] Note that the electrode 102B includes ITO and has a thickness of 70 nm.

[0522] <<Operation characteristics of light-emitting device 5>> When power was supplied, the light emitting device 5 emitted light EL1 and light EL12 (see FIG. 44A). The operating characteristics of the light emitting device 5 were measured (see FIGS. 45 to 51). The measurements were performed at room temperature. In addition, the light transmitted through the blue colored layer was measured. This resulted in measuring the blue light contained in the light emitted by the light emitting device 5. Specifically, the light EL12 was mainly measured (see FIG. 44A).

[0523] The main initial characteristics of the light-emitting device 5 are shown in Table 2.

[0524] The light-emitting device 5 was found to exhibit good characteristics. For example, 2 The voltage required to emit light with a luminance of 50 mA / cm was lower than that of Comparative Light-Emitting Device 4. 2 When the light-emitting device 5 was allowed to continue emitting light at a constant current density of 1000 s, the decrease in luminance was smaller than that of the comparative light-emitting device 4 (see FIG. 51). This enabled the reliability to be improved while suppressing the driving voltage. As a result, a novel light-emitting device with excellent convenience, usefulness, and reliability could be provided.

[0525] The light-emitting device 5 is different from the comparative light-emitting device 4 in that the layer 104(12) includes not only a region containing BBABnf and OCHD-001 in a ratio of BBABnf:OCHD-001=1:0.03 (weight ratio), but also a region 104A(12) containing OCHD-001 at a high concentration. This allows holes to be supplied to the unit 103(12) at a low voltage. The light-emitting device 5 is different from the comparative light-emitting device 4 in that the layer 104(12) includes not only a region containing OCHD-001 in a high concentration, but also a region 104B(12) containing BBABnf and OCHD-001 in a ratio of BBABnf:OCHD-001=1:0.03 (weight ratio). This allows the thickness of the layer 104(12) to be increased. Alternatively, the layer 104(12) can be used to cover unevenness occurring in the electrode 101. Alternatively, the layer 104(12) can be used to reduce unevenness at the interface caused by unevenness.

[0526] (Reference example 1) The configuration of the comparative light-emitting device 1 is shown in Table 7.

[0527] In the comparative light-emitting device 1 fabricated in this example, the layer 104 contains BBABnf and OCHD-001 in a weight ratio of BBABnf:OCHD-001=1:0.10.

[0528] [Table 7]

[0529] <<Method of manufacturing comparative light-emitting device 1>> Comparative light-emitting device 1A and comparative light-emitting device 1B were fabricated using a method having the following steps: Note that comparative light-emitting device 1A and comparative light-emitting device 1B were fabricated to have the same configuration.

[0530] The method for producing the comparative light-emitting device 1 differs from the methods for producing the light-emitting devices 1 to 3 in that in the step of forming the layer 104, a region containing OCHD-001 at a high concentration is not formed, and BBABnf and OCHD-001 are simply co-deposited at BBABnf:OCHD-001=1:0.10 (weight ratio). Therefore, the second step is omitted, and the first step is followed by the third step. Here, the differences are described in detail, and the above description is used for the parts in which a similar method is used.

[0531] [Third step] In a third step, a layer 104 was formed on the electrode 101. Specifically, materials were co-evaporated using a resistance heating method.

[0532] The layer 104 contains BBABnf and OCHD-001 in a weight ratio of BBABnf:OCHD-001=1:0.10, and has a thickness of 10 nm.

[0533] <Operation characteristics of comparative light-emitting device 1> The operating characteristics of the comparative light-emitting device 1A and the comparative light-emitting device 1B were measured at room temperature.

[0534] Table 2 shows the main initial characteristics of Comparative Light-Emitting Device 1A and Comparative Light-Emitting Device 1B.

[0535] (Reference example 2) The configuration of the comparative light-emitting device 2 is shown in Table 8.

[0536] In the comparative light-emitting device 2 fabricated in this example, layer 104 contains PCBBiF and OCHD-001 in a weight ratio of PCBBiF:OCHD-001=1:0.10.

[0537] [Table 8]

[0538] <<Method of producing comparative light-emitting device 2>> Comparative light-emitting device 2 was fabricated using a method having the following steps.

[0539] The method for producing comparative light-emitting device 2 differs from the method for producing light-emitting device 4 in that in the step of forming layer 104, a region containing OCHD-001 at a high concentration is not formed, and PCBBiF and OCHD-001 are simply co-deposited at PCBBiF:OCHD-001=1:0.10 (weight ratio). Therefore, step 10 is omitted, and the process proceeds to step 11 following step 9. Here, the differences will be described in detail, and the above description will be used for the parts where a similar method is used.

[0540] [11th step] In an eleventh step, the layer 104 was formed on the layer 106A by co-evaporation of materials using a resistive heating method.

[0541] Layer 104 contains PCBBiF and OCHD-001 in a weight ratio of PCBBiF:OCHD-001=1:0.10 and has a thickness of 10 nm.

[0542] <Operation characteristics of comparative light-emitting device 2> The operating characteristics of the comparative light-emitting device 2 were measured. The measurements were carried out at room temperature.

[0543] The main initial characteristics of the comparative light-emitting device 2 are shown in Table 2.

[0544] (Reference example 3) The configuration of comparative light-emitting device 3 is shown in Table 9.

[0545] The comparative light-emitting device 3 described in this example was fabricated in which layer 104 contains a high concentration of OCHD-001.

[0546] [Table 9]

[0547] <<Method of producing comparative light-emitting device 3>> Comparative light-emitting device 3 was fabricated using a method having the following steps.

[0548] The method for producing comparative light-emitting device 3 differs from the method for producing light-emitting device 4 in that in the step of forming layer 104, a region containing OCHD-001 at a high concentration is not formed, and PCBBiF and OCHD-001 are simply co-deposited at PCBBiF:OCHD-001=1:0.10 (weight ratio). Therefore, step 11 is omitted, and step 10 is followed by step 12. Here, the differences will be described in detail, and the above description will be used for the parts where a similar method is used.

[0549] [10th step] In a tenth step, the layer 104 was formed on the layer 106A. Specifically, the material was evaporated by using a resistive heating method.

[0550] Furthermore, layer 104 contains OCHD-001 in high concentration and has a thickness of 1 nm.

[0551] [12th step] In a twelfth step, a layer 112 was formed on the layer 104. Specifically, a material was evaporated using a resistive heating method.

[0552] Note that layer 112 includes PCBBiF and has a thickness of 25 nm.

[0553] <Operation characteristics of comparative light-emitting device 3> The operating characteristics of the comparative light-emitting device 3 were measured. The measurements were carried out at room temperature.

[0554] The main initial characteristics of the comparative light-emitting device 3 are shown in Table 2.

[0555] (Reference example 4) The configuration of the comparative light-emitting device 4 is shown in Table 10.

[0556] In the comparative light-emitting device 4 prepared in this example, the layer 104 (12) contains BBABnf and OCHD-001 in a weight ratio of BBABnf:OCHD-001=1:0.03.

[0557] [Table 10]

[0558] <<How to fabricate comparative light-emitting device 4>> Comparative light-emitting device 4 was fabricated using a method having the following steps.

[0559] The method for producing the comparative light-emitting device 4 differs from the method for producing the light-emitting device 5 in that, in the step of forming the layer 104(12), a region containing OCHD-001 at a high concentration is not formed, and BBABnf and OCHD-001 are simply co-deposited at BBABnf:OCHD-001=1:0.03 (weight ratio). Therefore, the third step is omitted, and the second step is followed by the fourth step. Here, the differences are described in detail, and the above description is used for the parts where a similar method is used.

[0560] [Fourth step] In the fourth step, a layer 104(12) was formed on the electrode 101. Specifically, materials were co-evaporated using a resistance heating method.

[0561] The layer 104(12) contains BBABnf and OCHD-001 in a weight ratio of BBABnf:OCHD-001=1:0.03 and has a thickness of 10 nm.

[0562] <Operation characteristics of comparative light-emitting device 4> The operating characteristics of the comparative light-emitting device 4 were measured. The measurements were performed at room temperature. In addition, the light transmitted through the blue colored layer was measured. As a result, the amount of blue light contained in the light emitted from the comparative light-emitting device 4 was measured.

[0563] The main initial characteristics of the comparative light-emitting device 4 are shown in Table 2.

[0564] This embodiment can be appropriately combined with other embodiment modes shown in this specification.

[0565] For example, when it is explicitly stated in this specification that X and Y are connected, the case where X and Y are electrically connected, the case where X and Y are functionally connected, and the case where X and Y are directly connected are considered to be disclosed in this specification, etc. Therefore, it is not limited to a specific connection relationship, for example, a connection relationship shown in a figure or text, and a connection relationship other than that shown in a figure or text is also considered to be disclosed in the figure or text.

[0566] Here, X and Y are objects (for example, a device, an element, a circuit, a wiring, an electrode, a terminal, a conductive film, a layer, etc.).

[0567] An example of a case where X and Y are directly connected is a case where an element that enables an electrical connection between X and Y (e.g., a switch, a transistor, a capacitance element, an inductor, a resistance element, a diode, a display element, a light-emitting element, a load, etc.) is not connected between X and Y, and a case where X and Y are connected without an element that enables an electrical connection between X and Y (e.g., a switch, a transistor, a capacitance element, an inductor, a resistance element, a diode, a display element, a light-emitting element, a load, etc.).

[0568] As an example of a case where X and Y are electrically connected, one or more elements (e.g., a switch, a transistor, a capacitance element, an inductor, a resistance element, a diode, a display element, a light-emitting element, a load, etc.) that enable the electrical connection between X and Y can be connected between X and Y. The switch has a function of controlling on / off. In other words, the switch has a function of being in a conductive state (on state) or a non-conductive state (off state) and controlling whether or not a current flows. Alternatively, the switch has a function of selecting and switching a path for the current to flow. The case where X and Y are electrically connected includes the case where X and Y are directly connected.

[0569] As an example of a case where X and Y are functionally connected, one or more circuits that enable the functional connection between X and Y (for example, logic circuits (inverters, NAND circuits, NOR circuits, etc.), signal conversion circuits (DA conversion circuits, AD conversion circuits, gamma correction circuits, etc.), potential level conversion circuits (power supply circuits (boosting circuits, step-down circuits, etc.), level shifter circuits that change the potential level of a signal, etc.), voltage sources, current sources, switching circuits, amplifier circuits (circuits that can increase the signal amplitude or current amount, operational amplifiers, differential amplifier circuits, source follower circuits, buffer circuits, etc.), signal generation circuits, memory circuits, control circuits, etc.) can be connected between X and Y. As an example, even if another circuit is sandwiched between X and Y, if a signal output from X is transmitted to Y, X and Y are considered to be functionally connected. Note that the case where X and Y are functionally connected includes the case where X and Y are directly connected and the case where X and Y are electrically connected.

[0570] In addition, when it is explicitly stated that X and Y are electrically connected, the following cases are considered to be disclosed in this specification etc.: when X and Y are electrically connected (i.e., when they are connected with another element or circuit between them), when X and Y are functionally connected (i.e., when they are functionally connected with another circuit between them), and when X and Y are directly connected (i.e., when they are connected without another element or circuit between them). In other words, when it is explicitly stated that they are electrically connected, the same content as when it is simply and explicitly stated that they are connected is considered to be disclosed in this specification etc.

[0571] For example, when the source (or the first terminal, etc.) of the transistor is electrically connected to X via (or without) Z1 and the drain (or the second terminal, etc.) of the transistor is electrically connected to Y via (or without) Z2, or when the source (or the first terminal, etc.) of the transistor is directly connected to a part of Z1, another part of Z1 is directly connected to X, the drain (or the second terminal, etc.) of the transistor is directly connected to a part of Z2, and another part of Z2 is directly connected to Y, it can be expressed as follows.

[0572] For example, it can be expressed as "X, Y, and the source (or first terminal, etc.) and drain (or second terminal, etc.) of the transistor are electrically connected to each other, and are electrically connected in the order of X, the source (or first terminal, etc.) of the transistor, the drain (or second terminal, etc.) of the transistor, and Y." Or, it can be expressed as "The source (or first terminal, etc.) of the transistor is electrically connected to X, the drain (or second terminal, etc.) of the transistor is electrically connected to Y, and X, the source (or first terminal, etc.) of the transistor, the drain (or second terminal, etc.) of the transistor, and Y are electrically connected in this order." Or, it can be expressed as "X is electrically connected to Y through the source (or first terminal, etc.) and drain (or second terminal, etc.) of the transistor, and X, the source (or first terminal, etc.) of the transistor, the drain (or second terminal, etc.) of the transistor, and Y are provided in this connection order." By using expressions similar to these examples to specify the order of connections in a circuit configuration, the source (or first terminal, etc.) and drain (or second terminal, etc.) of a transistor can be distinguished and the technical scope can be determined.

[0573] Alternatively, as another way of expressing it, for example, it can be expressed as "the source (or the first terminal, etc.) of the transistor is electrically connected to X via at least a first connection path, the first connection path does not have a second connection path, the second connection path is a path between the source (or the first terminal, etc.) of the transistor and the drain (or the second terminal, etc.) of the transistor via a transistor, the first connection path is a path via Z1, and the drain (or the second terminal, etc.) of the transistor is electrically connected to Y via at least a third connection path, the third connection path does not have the second connection path, and the third connection path is a path via Z2." Alternatively, it can be expressed as "the source (or the first terminal, etc.) of the transistor is electrically connected to X via Z1 by at least a first connection path, the first connection path does not have a second connection path, the second connection path has a connection path via a transistor, and the drain (or the second terminal, etc.) of the transistor is electrically connected to Y via Z2 by at least a third connection path, and the third connection path does not have the second connection path." Alternatively, it can be expressed as follows: "The source (or first terminal, etc.) of the transistor is electrically connected to X via Z1 by at least a first electrical path, the first electrical path does not have a second electrical path, the second electrical path is an electrical path from the source (or first terminal, etc.) of the transistor to the drain (or second terminal, etc.) of the transistor, and the drain (or second terminal, etc.) of the transistor is electrically connected to Y via Z2 by at least a third electrical path, the third electrical path does not have a fourth electrical path, and the fourth electrical path is an electrical path from the drain (or second terminal, etc.) of the transistor to the source (or first terminal, etc.) of the transistor." By using an expression method similar to these examples to define the connection path in the circuit configuration, the source (or first terminal, etc.) and the drain (or second terminal, etc.) of the transistor can be distinguished to determine the technical scope.

[0574] Note that these representation methods are merely examples and are not limited to these representation methods. Here, X, Y, Z1, and Z2 are objects (for example, a device, an element, a circuit, a wiring, an electrode, a terminal, a conductive film, a layer, etc.).

[0575] In addition, even when components that are independent on a circuit diagram are shown as being electrically connected to each other, one component may have the functions of multiple components. For example, when a part of a wiring also functions as an electrode, one conductive film has both the functions of a wiring and an electrode. Therefore, the term "electrical connection" in this specification also includes such a case where one conductive film has the functions of multiple components. [Explanation of symbols]

[0576] HOMO1: first HOMO level, HOMO2: second HOMO level, LUMO1: first LUMO level, LUMO2: second LUMO level, 101: electrode, 102: electrode, 102A: electrode, 102B: electrode, 103: unit, 104: layer, 104A: region, 104B: region, 104(12): layer, 105: layer, 106: intermediate layer, 106A: layer, 106B: layer, 111: layer, 112: layer, 112A: region, 112B: region, 113: layer, 113A: region, 113B: region, 150: light-emitting device, 400: substrate, 401: first electrode, 403: EL layer, 404: second electrode, 405: sealing material, 406: sealing material, 407: sealing substrate, 412: pad, 420: IC chip, 601: source line driving circuit, 602: pixel section, 603: gate line driving circuit, 604: sealing substrate, 605: sealing material, 607: space, 608: wiring, 610: element substrate, 611: switching FET, 612: current control FET, 613: first electrode, 614: insulator, 616: EL layer, 617: second electrode, 618: light emitting device, 623: FET, 700: light emitting panel, 951: substrate, 952: electrode, 953: insulating layer, 9 54: partition layer, 955: EL layer, 956: electrode, 1001: substrate, 1002: base insulating film, 1003: gate insulating film, 1006: gate electrode, 1007: gate electrode, 1008: gate electrode, 1020: first interlayer insulating film, 1021: second interlayer insulating film, 1022: electrode, 1024B: first electrode, 1024G: first electrode, 1024R: first electrode, 1024W: first electrode, 1025: partition, 1028: EL layer, 1029: second electrode, 1031: sealing substrate, 1032: sealing material, 1033: base material, 1034B: colored layer, 1034G: colored layer, 1034 R: colored layer, 1035: black matrix, 1036: overcoat layer, 1037: third interlayer insulating film, 1040: pixel section, 1041: driving circuit section, 1042: peripheral section, 2001: housing, 2002: light source, 2100: robot, 2101: illuminance sensor, 2102: microphone, 2103: upper camera, 2104: speaker, 2105: display, 2106: lower camera, 2107: obstacle sensor, 2108: moving mechanism, 2110: computing device, 3001: lighting device, 5000: housing, 5001: display section, 5002: display section, 5003: speaker,5004: LED lamp, 5006: connection terminal, 5007: sensor, 5008: microphone, 5012: support, 5013: earphone, 5100: cleaning robot, 5101: display, 5102: camera, 5103: brush, 5104: operation button, 5120: dust, 5140: portable electronic device, 5200: display area, 5201: display area, 5202: display area, 5203: display area, 7101: housing, 7103: display unit, 7105: stand, 710 7: display unit, 7109: operation keys, 7110: remote control unit, 7201: main body, 7202: housing, 7203: display unit, 7204: keyboard, 7205: external connection port, 7206: pointing device, 7210: second display unit, 7401: housing, 7402: display unit, 7403: operation buttons, 7404: external connection port, 7405: speaker, 7406: microphone, 9310: mobile information terminal, 9311: display panel, 9313: hinge, 9315: housing,

Claims

1. A first electrode; A second electrode; and The unit, a first layer; the second electrode has an area overlapping with the first electrode; the unit includes a region sandwiched between the first electrode and the second electrode; the unit comprises a second layer and a third layer; the second layer has a region sandwiching the third layer between the first electrode and the second layer, the second layer comprises a luminescent material; the first layer comprises a region sandwiched between the third layer and the first electrode; the first layer comprises a first region and a second region; the first region comprises a region sandwiched between the second region and the first electrode; the first region includes only a material having acceptor properties; The second region comprises the acceptor material and a first material.

2. A first electrode; A second electrode; and The unit, a first layer; the second electrode has an area overlapping with the first electrode; the unit includes a region sandwiched between the first electrode and the second electrode; the unit comprises a second layer, a third layer and a fourth layer; the second layer has a region sandwiching the third layer between the first electrode and the second layer, the second layer comprises a luminescent material; the first layer comprises a region sandwiched between the third layer and the first electrode; the first layer comprises a first region and a second region; the first region comprises a region sandwiched between the second region and the first electrode; the first region includes only a material having acceptor properties; the second region includes the material having acceptor properties and a first material; the fourth layer comprises a region sandwiched between the second electrode and the second layer; the fourth layer comprises a third material; the third material is an organic complex of an alkali metal or an organic complex of an alkaline earth metal; the third layer comprises a third region and a fourth region; the fourth region comprises a region sandwiched between the second layer and the third region; the fourth region comprises a second material; the first material has a first HOMO level; the first HOMO level is −5.7 eV or more and −5.4 eV or less; the second material has a second HOMO level; The second HOMO level is in the range of −0.2 eV to 0 eV with respect to the first HOMO level.

3. A first electrode; A second electrode; and The unit, a first layer; the second electrode has an area overlapping with the first electrode; the unit includes a region sandwiched between the first electrode and the second electrode; the unit comprises a second layer, a third layer and a fourth layer; the second layer has a region sandwiching the third layer between the first electrode and the second layer, the second layer comprises a light-emitting material and a fourth material; the fourth material has a first LUMO level; the first layer comprises a region sandwiched between the third layer and the first electrode; the first layer comprises a first region and a second region; the first region comprises a region sandwiched between the second region and the first electrode; the first region includes only a material having acceptor properties; the second region includes the material having acceptor properties and a first material; the fourth layer comprises a region sandwiched between the second electrode and the second layer; the fourth layer comprises a third material; the third material is an organic complex of an alkali metal or an organic complex of an alkaline earth metal; the third layer comprises a third region and a fourth region; the fourth region comprises a region sandwiched between the second layer and the third region; the fourth region comprises a second material; the first material has a first HOMO level; the first HOMO level is −5.7 eV or more and −5.4 eV or less; the second material has a second HOMO level; the second HOMO level is in the range of −0.2 eV to 0 eV with respect to the first HOMO level, the fourth layer comprises a fifth region and a sixth region; the fifth region comprises a region sandwiched between the sixth region and the second layer; the fifth region comprises a fifth material; the sixth region includes the third material; the fifth material has a second LUMO level; The second LUMO level is in the range of -0.4 eV to -0.1 eV with respect to the first LUMO level.

4. In any one of claims 1 to 3, The first region contacts the first electrode.

5. A light emitting apparatus comprising the light emitting device according to claim 1 and a transistor.

6. 6. An electronic device comprising: the light emitting device according to claim 5; and a sensor, an operation button, a speaker, or a microphone.

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