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

Abstract

Provided is a novel organometallic complex with high reliability. A light-emitting element includes an EL layer between a pair of electrodes. The EL layer includes at least a light-emitting layer. The light-emitting layer contains an organometallic complex. The organometallic complex includes a first ligand and a second ligand coordinated to a central metal. The HOMO is distributed on the first ligand, and the LUMO is distributed on the second ligand. The first ligand and the second ligand are cyclometalated ligands.

Description

[0001] This application is a divisional application of the following patent application:

[0002] Title of the Invention: Light-emitting Element, Light-emitting Device, Electronic Device, and Lighting Device; Application Date: March 24, 2017; Application Number: 201780021354.6. Technical Field

[0003] One embodiment of the present invention relates to a light-emitting element, a light-emitting device, an electronic device, and a lighting device using an organometallic complex. 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 and the like relates to an object, a method, or a manufacturing method. One embodiment of the present invention relates to a process, a machine, a manufacture, a substance (organometallic complex), or a composition of matter. Specifically, other examples of the technical field of one embodiment of the invention disclosed in this specification include semiconductor devices, display devices, liquid crystal display devices, power storage devices, storage devices, driving methods of these devices, or manufacturing methods of these devices. Background Art

[0004] A light-emitting element (also referred to as an organic EL element) having a structure in which an organic compound as a light-emitting substance is included between a pair of electrodes has characteristics such as being thin, lightweight, having a high response speed, and being able to be driven at a low voltage. A display including such a light-emitting element has attracted attention as a next-generation flat panel display. When a voltage is applied to the above light-emitting element, electrons and holes injected from the electrodes recombine, so that the light-emitting substance becomes an excited state, and light is emitted when returning from this excited state to the ground state. The types of excited states can be singlet excited states (S * ) and triplet excited states (T * ). Luminescence from singlet excited states is called fluorescence, and luminescence from triplet excited states is called phosphorescence. In a light-emitting element, the statistically generated ratio of singlet excited states and triplet excited states is considered to be S * : T * = 1:3.

[0005] As the above light-emitting substance, a compound capable of converting the energy of singlet excited states into light is called a fluorescent compound (fluorescent material), and a compound capable of converting the energy of triplet excited states into light is called a phosphorescent compound (phosphorescent material).

[0006] Therefore, based on the above generation ratio, the theoretical limit of the internal quantum efficiency (the ratio of the number of generated photons to the number of injected carriers) of a light-emitting element including a fluorescent material is considered to be 25%, while the theoretical limit of the internal quantum efficiency of a light-emitting element including a phosphorescent material is considered to be 75%.

[0007] In other words, compared with a light-emitting element including a fluorescent material, a light-emitting element including a phosphorescent material has higher efficiency. Therefore, various phosphorescent materials have been actively researched and developed in recent years. In particular, organometallic complexes containing iridium or the like as a central metal have attracted attention due to their high phosphorescent quantum yield (for example, refer to Patent Document 1).

[0008] [Patent Document]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-23938 Summary of the Invention

[0010] As reported in the above Patent Document 1, the development of phosphorescent materials with excellent properties has progressed, but the development of novel materials with even more excellent properties is expected.

[0011] Then, according to one embodiment of the present invention, there is provided a novel light-emitting element with high reliability. According to one embodiment of the present invention, there is provided a novel organometallic complex that can be used for a light-emitting element. According to one embodiment of the present invention, there is provided a novel organometallic complex that can be used for an EL layer of a light-emitting element. According to one embodiment of the present invention, there is provided a novel light-emitting device, a novel electronic device, or a novel lighting device. Note that the description of these objects does not prevent the existence of other objects. One embodiment of the present invention does not need to achieve all of the above objects. Other objects can be naturally understood from the description in the specification, drawings, claims, etc., and other objects can be derived from the description in the specification, drawings, claims, etc.

[0012] One embodiment of the present invention is a light-emitting element including an EL layer between a pair of electrodes. The EL layer includes at least a light-emitting layer. The light-emitting layer contains an organometallic complex. The organometallic complex includes a first ligand and a second ligand coordinated to a central metal. The first ligand has a HOMO, and the second ligand has a LUMO. The first ligand and the second ligand are cyclometalated ligands.

[0013] One embodiment of the present invention is a light-emitting element including an EL layer between a pair of electrodes. The EL layer includes at least a light-emitting layer. The light-emitting layer contains an organometallic complex. The organometallic complex includes a first ligand and a second ligand coordinated to a central metal. The HOMO is distributed on the first ligand, and the LUMO is distributed on the second ligand. The first ligand and the second ligand are cyclometalated ligands.

[0014] In the above-described embodiment, the first heteroaromatic ring coordinated to the central metal and included in the first ligand is different from the second heteroaromatic ring coordinated to the central metal and included in the second ligand.

[0015] In the above-described embodiment, the first heteroaromatic ring includes a first monocyclic ring containing a nitrogen atom coordinated to the central metal, the second heteroaromatic ring includes a second monocyclic ring containing a nitrogen atom coordinated to the central metal, and the first monocyclic ring is different from the second monocyclic ring.

[0016] In the above-described embodiment, the ring size of each of the first monocyclic ring and the second monocyclic ring is 5 or 6.

[0017] In the above-described embodiment, the number of nitrogen atoms in the first monocyclic ring is 1, and the number of nitrogen atoms in the second monocyclic ring is 2 or 3.

[0018] In the above-described embodiment, the first monocyclic ring is a pyridine ring, and the second monocyclic ring is a pyrimidine ring or a triazine ring.

[0019] In the above-described embodiment, the first heteroaromatic ring is a pyridine ring, and the second heteroaromatic ring is a pyrimidine ring or a triazine ring.

[0020] In the above-described embodiment, the central metal is preferably iridium. At this time, since iridium is trivalent, the total number of the first ligand and the second ligand in the organometallic complex is preferably 3. At this time, it is preferable that the number of the first ligands in the HOMO distribution is 2 and the number of the second ligands in the LUMO distribution is 1.

[0021] Another embodiment of the present invention is an organometallic complex having a structure represented by the following general formula (G1).

[0022] [Chemical formula 1]

[0023]

[0024] In the general formula (G1), R 1 to R 15 each independently represents hydrogen, a halogen group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

[0025] Another embodiment of the present invention is an organometallic complex having a structure represented by the following general formula (G2).

[0026] [Chemical formula 2]

[0027]

[0028] In the general formula (G2), n is 1 or 2. R 1 to R 15Each independently represents hydrogen, a halogen group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

[0029] Since the HOMO and LUMO are spatially separated because they are distributed on different ligands, the organometallic complexes used in the light-emitting element of one embodiment of the present invention generally have a shallow HOMO and a deep LUMO. Therefore, by using such organometallic complexes, the carrier injection property and carrier transport property with respect to electrons and holes are improved. Thereby, by using them as a light-emitting material in a light-emitting element, the driving voltage is reduced and the efficiency is improved. In addition, in the organometallic complex for a light-emitting element of one embodiment of the present invention, when transporting carriers and when in an excited state, holes are distributed on a ligand with high hole resistance (a first ligand where HOMO is likely to be distributed), and electrons are distributed on a ligand with high electron resistance (a second ligand where LUMO is likely to be distributed). Thereby, the stability when transporting carriers and when in an excited state can be increased, and a light-emitting element with a long service life can be manufactured. In addition, due to such separation of HOMO and LUMO, the organometallic complex itself can transport both carriers, so the carrier balance can be adjusted. This also contributes to an increase in the service life.

[0030] One embodiment of the present invention includes not only a light-emitting device having a light-emitting element within its scope, but also a lighting device having a light-emitting device. Therefore, the light-emitting device in this specification refers to an image display device and a light source (for example, a lighting device). In addition, the light-emitting device also includes all the following modules within its scope: a module in which a connector such as an FPC (Flexible Printed Circuit) or a TCP (Tape Carrier Package) is installed in the light-emitting device; a module in which a printed circuit board is provided at the end of the TCP; or a module in which an IC (integrated circuit) is directly mounted on the light-emitting element by the COG (Chip On Glass) method.

[0031] According to one embodiment of the present invention, a novel light-emitting element with high reliability can be provided. According to one embodiment of the present invention, a novel organometallic complex that can be used for a light-emitting element can be provided. According to one embodiment of the present invention, a novel light-emitting device, a novel electronic device, or a novel lighting device is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1A and Figure 1B shows the structure of the light-emitting element.

[0033] Figure 2A and Figure 2B show the structure of the light-emitting element.

[0034] Figures 3A to 3C show the light-emitting device.

[0035] Figure 4A and Figure 4B show the light-emitting device.

[0036] Figure 5A , Figure 5B , Figure 5C , Figure 5D , Figure 5D’-1 and Figure 5D’-2 show the electronic device.

[0037] Figures 6A to 6C show the electronic device.

[0038] Figure 7A and Figure 7B show the vehicle.

[0039] Figures 8A to 8D show the lighting device.

[0040] Figure 9 show the lighting device.

[0041] Figure 10A and Figure 10B show an example of the touch screen.

[0042] Figure 11A and Figure 11B show an example of the touch screen.

[0043] Figure 12A and Figure 12B show an example of the touch screen.

[0044] Figure 13A and Figure 13B is the block diagram and timing diagram of the touch sensor.

[0045] Figure 14 is the circuit diagram of the touch sensor.

[0046] Figure 15A , Figure 15B1 and Figure 15B2 show the block diagram of the display device.

[0047] Figure 16 show the circuit structure of the display device.

[0048] Figure 17 show the cross-sectional structure of the display device.

[0049] Figure 18A and Figure 18BShows a light-emitting element.

[0050] Figure 19 Is the 1 1H-NMR spectrum of the organometallic complex represented by structural formula (100).

[0051] Figure 20 Shows the ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by structural formula (100).

[0052] Figure 21 Shows the LC-MS measurement results of the organometallic complex represented by structural formula (100).

[0053] Figure 22 Shows the 1 1H-NMR spectrum of the organometallic complex represented by structural formula (102).

[0054] Figure 23 Shows the ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by structural formula (102).

[0055] Figure 24 Shows the LC-MS measurement results of the organometallic complex represented by structural formula (102).

[0056] Figure 25 Shows the 1 1H-NMR spectrum of the organometallic complex represented by structural formula (114).

[0057] Figure 26 Shows the ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by structural formula (114).

[0058] Figure 27 Shows the LC-MS measurement results of the organometallic complex represented by structural formula (114).

[0059] Figure 28 Shows the 1 1H-NMR spectrum of the organometallic complex represented by structural formula (120).

[0060] Figure 29 Shows the ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by structural formula (120).

[0061] Figure 30 Shows the LC-MS measurement results of the organometallic complex represented by structural formula (120).

[0062] Figure 31 Shows a light-emitting element.

[0063] Figure 32Shows the current density - luminance characteristics of the light - emitting element.

[0064] Figure 33 Shows the voltage - luminance characteristics of the light - emitting element.

[0065] Figure 34 Shows the luminance - current efficiency characteristics of the light - emitting element.

[0066] Figure 35 Shows the voltage - current characteristics of the light - emitting element.

[0067] Figure 36 Shows the emission spectrum of the light - emitting element.

[0068] Figure 37 Shows the reliability of the light - emitting element.

[0069] Figure 38 Shows the current density - luminance characteristics of the light - emitting element.

[0070] Figure 39 Shows the voltage - luminance characteristics of the light - emitting element.

[0071] Figure 40 Shows the luminance - current efficiency characteristics of the light - emitting element.

[0072] Figure 41 Shows the voltage - current characteristics of the light - emitting element.

[0073] Figure 42 Shows the emission spectrum of the light - emitting element.

[0074] Figure 43 Shows the 1 1H - NMR spectrum of the organometallic complex represented by the structural formula (117).

[0075] Figure 44 Shows the ultraviolet - visible absorption spectrum and emission spectrum of the organometallic complex represented by the structural formula (117).

[0076] Figure 45 Shows the LC - MS measurement results of the organometallic complex represented by the structural formula (117).

[0077] Figure 46 Shows the 1 1H - NMR spectrum of the organometallic complex represented by the structural formula (200).

[0078] Figure 47 Shows the ultraviolet - visible absorption spectrum and emission spectrum of the organometallic complex represented by the structural formula (200).

[0079] Figure 48Shows the LC-MS measurement results of the organometallic complex represented by the structural formula (200).

[0080] Figure 49 Shows the 1 1H-NMR spectrum of the organometallic complex represented by the structural formula (300).

[0081] Figure 50 Shows the ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by the structural formula (300).

[0082] Figure 51 Shows the LC-MS measurement results of the organometallic complex represented by the structural formula (300).

[0083] Figure 52 Shows the 1 1H-NMR spectrum of the organometallic complex represented by the structural formula (118).

[0084] Figure 53 Shows the ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by the structural formula (118).

[0085] Figure 54 Shows the 1 1H-NMR spectrum of the organometallic complex represented by the structural formula (119).

[0086] Figure 55 Shows the ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by the structural formula (119).

[0087] Figure 56 Shows the LC-MS measurement results of the organometallic complex represented by the structural formula (119).

[0088] Figure 57 Shows the current density-luminance characteristics of the light-emitting element.

[0089] Figure 58 Shows the voltage-luminance characteristics of the light-emitting element.

[0090] Figure 59 Shows the luminance-current efficiency characteristics of the light-emitting element.

[0091] Figure 60 Shows the voltage-current characteristics of the light-emitting element.

[0092] Figure 61 Shows the emission spectrum of the light-emitting element.

[0093] Figure 62 Shows the reliability of the light-emitting element.

[0094] Figure 63 Shows the current density - luminance characteristics of the light - emitting element.

[0095] Figure 64 Shows the voltage - luminance characteristics of the light - emitting element.

[0096] Figure 65 Shows the luminance - current efficiency characteristics of the light - emitting element.

[0097] Figure 66 Shows the voltage - current characteristics of the light - emitting element.

[0098] Figure 67 Shows the emission spectrum of the light - emitting element.

[0099] Figure 68 Shows the reliability of the light - emitting element. Detailed implementation mode

[0100] Hereinafter, the implementation mode of the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following description, and its mode and detailed content can be changed into various forms without departing from the gist and scope of the present invention. Therefore, the present invention should not be construed as being limited only to the content described in the following implementation modes.

[0101] In addition, depending on the situation or state, the terms "film" and "layer" can be interchanged with each other. For example, sometimes the term "conductive layer" can be interchanged with the term "conductive film". In addition, sometimes the term "insulating film" can be interchanged with the term "insulating layer".

[0102] (Embodiment 1)

[0103] In this embodiment, Figure 1A and Figure 1B are used to describe a light - emitting element according to an embodiment of the present invention.

[0104] In the light - emitting element shown in this embodiment, an EL layer 102 including a light - emitting layer 113 is provided between a pair of electrodes (a first electrode (anode) 101 and a second electrode (cathode) 103). The EL layer 102 includes a hole injection layer 111, a hole transport layer 112, an electron transport layer 114, an electron injection layer 115, etc. in addition to the light - emitting layer 113. Note that the light - emitting layer 113 contains a light - emitting substance.

[0105] When a voltage is applied to the above - mentioned light - emitting element, holes injected from the first electrode 101 side and electrons injected from the second electrode 103 side recombine in the light - emitting layer 113, and light - emitting substances such as organometallic complexes contained in the light - emitting layer 113 emit light using the energy generated by the recombination.

[0106] The light-emitting layer 113 preferably contains a host material and a guest material as a light-emitting substance. At this time, in the light-emitting layer 113, the host material is present in the highest weight ratio, and the guest material is distributed in the host material. In addition, a substance having a triplet excitation energy level higher than that of the guest material is preferably used as the host material.

[0107] In the light-emitting element according to an embodiment of the present invention, as the light-emitting substance of the light-emitting layer included in the EL layer, an organometallic complex is preferably used, and an organometallic complex according to an embodiment of the present invention is more preferably used. The organometallic complex according to an embodiment of the present invention includes a first ligand and a second ligand coordinated to a central metal. The highest occupied molecular orbital (HOMO) is distributed on the first ligand, and the lowest unoccupied molecular orbital (LUMO) is distributed on the second ligand. The first ligand and the second ligand are cyclometalated ligands. In addition, the central metal is preferably iridium, platinum, or the like.

[0108] As a method of distributing the HOMO on the first ligand and the LUMO on the second ligand, the first heteroaromatic ring included in the first ligand coordinated to the central metal is preferably different from the second heteroaromatic ring included in the second ligand coordinated to the central metal. However, as long as the HOMO is distributed on the first ligand and the LUMO is distributed on the second ligand, an embodiment of the present invention is not necessarily limited to the above method. In addition, examples of the first heteroaromatic ring included in the first ligand on which the HOMO is easily distributed include a pyridine ring, a quinoline ring, an isoquinoline ring, an imidazole ring, a benzimidazole ring, etc., and examples of the second heteroaromatic ring included in the second ligand on which the LUMO is easily distributed include a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, a cinnoline ring, a phthalazine ring, a quinazoline ring, a quinoxaline ring, etc.

[0109] When separating the HOMO and LUMO as described above, it is important that the portions of the first heteroaromatic ring and the second heteroaromatic ring coordinated to the central metal have different ring structures. That is, when a nitrogen atom is coordinated to the central metal, it is important that the monocyclic structures of the first heteroaromatic ring and the second heteroaromatic ring containing the nitrogen atom are different. Therefore, in one embodiment of the present invention, the first heteroaromatic ring includes a first monocyclic ring containing a nitrogen atom coordinated to the central metal, the second heteroaromatic ring includes a second monocyclic ring of a nitrogen atom coordinated to the central metal, and the first monocyclic ring is different from the second monocyclic ring. For example, when the first heteroaromatic ring included in the first ligand is quinoline and the nitrogen atom of quinoline is coordinated to the central metal, the first monocyclic ring refers to a pyridine ring. When the second heteroaromatic ring included in the second ligand is quinoxaline and the nitrogen atom of quinoxaline is coordinated to the central metal, the second monocyclic ring refers to a pyrazine ring. When the first heteroaromatic ring is a monocyclic ring, the first heteroaromatic ring is substantially the same as the first monocyclic ring. Similarly, when the second heteroaromatic ring is a monocyclic ring, the second heteroaromatic ring is substantially the same as the second monocyclic ring. By adopting such a structure, it is easier to separate the HOMO and LUMO. Note that the first monocyclic ring and the second monocyclic ring are each preferably a five-membered ring or a six-membered ring.

[0110] In the above structure, the number of nitrogen atoms in the first monocyclic ring is 1, and the number of nitrogen atoms in the second monocyclic ring is 2 or 3. The larger the number of nitrogen atoms, the more electron-deficient the nitrogen-containing heteroaromatic ring becomes and has a lower HOMO and a lower LUMO. Therefore, by setting the number of nitrogen atoms in pyridine or the first monocyclic ring to 1 and the number of nitrogen atoms in the second monocyclic ring to 2 or 3, the HOMO and LUMO are more easily distributed on the first ligand and the second ligand, respectively. From such a viewpoint, preferably, the first monocyclic ring is a pyridine ring and the second monocyclic ring is a pyrimidine ring or a triazine ring. When the first monocyclic ring is a pyridine ring, the first heteroaromatic ring is preferably a pyridine ring, a quinoline ring or an isoquinoline ring, and when the second monocyclic ring is a pyrimidine ring or a triazine ring, the second heteroaromatic ring is preferably a pyrimidine ring, a triazine ring or a quinazoline ring.

[0111] In the above structure, in terms of sublimation, the first heteroaromatic ring and the second heteroaromatic ring are each preferably a monocyclic ring. That is, preferably, the first heteroaromatic ring is a pyridine ring and the second heteroaromatic ring is a pyrimidine ring or a triazine ring.

[0112] When the central metal in the above structure is iridium, since iridium is trivalent, the total number of the first ligand and the second ligand in the organometallic complex is preferably 3. Due to the above structure, the organometallic complex may include only the first ligand and the second ligand as ligands. Therefore, the HOMO and LUMO are more easily distributed on the first ligand and the second ligand, respectively. At this time, preferably, the number of the first ligands on which the HOMO is distributed is 2, and the number of the second ligands on which the LUMO is distributed is 1. The present inventors have found that such a structure has a particularly remarkable effect on extending the service life.

[0113] Note that the above organometallic complex is represented by the following general formula (G1) or the following general formula (G2). The organometallic complexes represented by the general formula (G1) and the general formula (G2) are included in one embodiment of the present invention.

[0114] [Chemical formula 3]

[0115]

[0116] In the general formula (G1), R 1 to R 15 each independently represents hydrogen, a halogen group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

[0117] [Chemical formula 4]

[0118]

[0119] In the general formula (G2), n is 1 or 2. R 1 to R 15 each independently represents hydrogen, a halogen group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

[0120] Specific examples of the alkyl group having 1 to 6 carbon atoms represented by any one of R 1 to R 15 in the above general formulas (G1) and (G2) include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl, sec-pentyl, tert-pentyl, neopentyl, hexyl, isohexyl, sec-hexyl, tert-hexyl, neohexyl, 3-methylpentyl, 2-methylpentyl, 2-ethylbutyl, 1,2-dimethylbutyl, 2,3-dimethylbutyl, and trifluoromethyl, etc.

[0121] Specific examples of the aryl group having 6 to 13 carbon atoms represented by any one of R 1 to R 15 in the above general formulas (G1) and (G2) include phenyl, tolyl (o-tolyl, m-tolyl, p-tolyl), naphthyl (1-naphthyl, 2-naphthyl), biphenyl (biphenyl-2-yl, biphenyl-3-yl, biphenyl-4-yl), xylenyl, pentaphenylenyl, indenyl, fluorenyl, phenanthryl, etc. In addition, the above substituents may be bonded to each other to form a ring. At this time, for example, the carbon at the 9-position of the fluorenyl group has two phenyl groups as substituents and the phenyl groups are bonded to each other, thus forming a spirofluorene skeleton.

[0122] In the above general formulas (G1) and (G2), R 1 to R 15 Specific examples of the heteroaryl group having 3 to 12 carbon atoms represented by any of them include imidazolyl, pyrazolyl, pyridyl, pyridazyl group, triazyl group, benzimidazolyl, quinolinyl, carbazolyl, dibenzofuranyl, dibenzothiophenyl, and the like.

[0123] In each of the general formulas (G1) and (G2), when any one of the substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, the substituted or unsubstituted aryl group having 6 to 13 carbon atoms, and the substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms has a substituent, examples of the substituent include alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl; cycloalkyl groups having 5 to 7 carbon atoms such as cyclopentyl, cyclohexyl, cycloheptyl, 1-norbornanyl, 2-norbornanyl; aryl groups having 6 to 12 carbon atoms such as phenyl, biphenyl. The above substituents may also be bonded to each other to form a ring. At this time, for example, when any one of R 1 to R 15 is a fluorenyl group which is an aryl group having 13 carbon atoms, and the carbon at the 9-position of the fluorenyl group has two phenyl groups as substituents, and these phenyl groups are bonded to each other, a spirofluorene skeleton is formed.

[0124] The organometallic complexes represented by the following structural formulas (100) to (116), (200), (201), (300) and (301) can be used in the light-emitting element of one embodiment of the present invention.

[0125] [Chemical formula 5]

[0126]

[0127] [Chemical formula 6]

[0128]

[0129] [Chemical formula 7]

[0130]

[0131] Note that by using any of the above organometallic complexes in the light-emitting layer 113 of the light-emitting element, the light-emitting element can achieve low driving voltage, high luminous efficiency, long service life, and high reliability.

[0132] Since the HOMO and LUMO are spatially separated because they are distributed on different ligands, the above-mentioned organometallic complex generally has a shallow HOMO and a deep LUMO. By using such an organometallic complex, the carrier injection property and carrier transport property with respect to electrons and holes are improved. Thereby, by using them as a light-emitting material in a light-emitting element, the driving voltage is reduced and the efficiency is improved. In addition, in the organometallic complex for a light-emitting element according to one embodiment of the present invention, when transporting carriers and when in an excited state, holes are distributed on a ligand with high hole resistance (a first ligand where HOMO is likely to be distributed), and electrons are distributed on a ligand with high electron resistance (a second ligand where LUMO is likely to be distributed). Thereby, the stability when transporting carriers and when in an excited state can be increased, and a light-emitting element with a long service life can be manufactured. In addition, due to such separation of HOMO and LUMO, the organometallic complex itself can transport both carriers, so the carrier balance can be adjusted. This also contributes to an increase in the service life.

[0133] In the case where an organometallic complex including only the first ligand has a first driving life and an organometallic complex including only the second ligand has a second driving life, the service life of the organometallic complex including a combination of the first ligand and the second ligand is generally predicted to be limited by the shorter one of the first driving life and the second driving life, or predicted to be a life between the first driving life and the second driving life. However, as shown in one embodiment of the present invention, due to the separation of HOMO and LUMO caused by the combination of the first ligand and the second ligand, a service life longer than the first driving life and the second driving life can be achieved. The present inventors newly discovered this amazing phenomenon.

[0134] The organometallic complex represented by the above structural formula is a novel substance capable of emitting phosphorescence. Depending on the type of ligand, these substances may have geometric isomers or stereoisomers. Each isomer is also an organometallic complex according to one embodiment of the present invention.

[0135] Next, an example of a synthesis method of the organometallic complex represented by the general formula (G1) will be described.

[0136] [Chemical formula 8]

[0137]

[0138] 《Synthesis Method of Organometallic Complex Represented by General Formula (G1)》

[0139] As shown in the following synthesis scheme (A), in an inert gas atmosphere, a binuclear complex (P1) having a structure crosslinked by a halogen is reacted with a pyridine compound represented by the general formula (G0-a), whereby an organometallic complex represented by the general formula (G1) and being an embodiment of the present invention can be obtained.

[0140] [Chemical formula 9]

[0141]

[0142] In the synthesis scheme (A), X represents a halogen atom, and R 1 to R 15 each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

[0143] The organometallic complex obtained in the synthesis scheme (A) can be irradiated with light or heated to cause it to further react. At this time, isomers such as geometric isomers or optical isomers can be obtained. This isomer is also an organometallic complex represented by the general formula (G1). After reacting a binuclear complex (P1) having a structure crosslinked by a halogen with a dechlorinating agent such as silver trifluoromethanesulfonate to precipitate silver chloride, the clarified liquid can be reacted with a pyridine compound represented by the general formula (G0-a) in an inert gas atmosphere.

[0144] Next, an example of a method for synthesizing an organometallic complex represented by the general formula (G2-a) will be described.

[0145] [Chemical formula 10]

[0146]

[0147] "Method for Synthesizing Organometallic Complex Represented by General Formula (G2-a)"

[0148] As shown in the following synthesis scheme (B), in an inert gas atmosphere, a binuclear complex (P2) having a structure crosslinked by a halogen is reacted with a pyridine compound represented by the general formula (G0-a), whereby an organometallic complex represented by the general formula (G2-a) and being an embodiment of the present invention can be obtained.

[0149] [Chemical formula 11]

[0150]

[0151] In the synthesis scheme (B), X represents a halogen atom, and R 1 to R 15Each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

[0152] The organometallic complex obtained in Synthesis Scheme (B) can be irradiated with light or heated to cause further reaction, and at this time, isomers such as geometric isomers or optical isomers can be obtained. This isomer is also an organometallic complex represented by the general formula (G2-a). After reacting the binuclear complex (P2) having a structure crosslinked by halogen with a dechlorinating agent such as silver trifluoromethanesulfonate to precipitate silver chloride, the clarified liquid can be reacted with a pyridine compound represented by the general formula (G0-a) in an inert gas atmosphere.

[0153] Next, an example of a method for synthesizing an organometallic complex represented by the following general formula (G2-b) will be described.

[0154] [Chemical formula 12]

[0155]

[0156] "Synthesis Method of Organometallic Complex Represented by General Formula (G2-b)"

[0157] As shown in the following Synthesis Scheme (C), in an inert gas atmosphere, a binuclear complex (P3) having a structure crosslinked by halogen is reacted with a triazine compound represented by the general formula (G0-b), whereby an organometallic complex which is an embodiment of the present invention and is represented by the general formula (G2-a) can be obtained.

[0158] [Chemical formula 13]

[0159]

[0160] In Synthesis Scheme (C), X represents a halogen atom, and R 1 to R 15 Each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms.

[0161] The organometallic complex obtained in Synthesis Scheme (C) can be irradiated with light or heated to cause further reaction, and at this time, isomers such as geometric isomers or optical isomers can be obtained. This isomer is also an organometallic complex represented by the general formula (G2-b). After reacting the binuclear complex (P3) having a structure crosslinked by halogen with a dechlorinating agent such as silver trifluoromethanesulfonate to precipitate silver chloride, the clarified liquid can be reacted with a triazine compound represented by the general formula (G0-b) in an inert gas atmosphere.

[0162] In the organometallic complex of an embodiment of the present invention described above, in order to obtain an ortho-metal complex containing a pyrimidine or triazine compound as a ligand, a substituent is preferably bonded to R of the pyrimidine or triazine compound 6 . As R 6 , it is particularly preferable to use a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 12 carbon atoms. At this time, compared with the case where hydrogen is used as R 6 , the decomposition of the binuclear metal complex crosslinked by halogen in the reaction represented by the synthesis scheme (A), (B), or (C) can be further suppressed, and thus an extremely high yield can be obtained.

[0163] The above describes an example of the synthesis method of the organometallic complex for a light-emitting element of an embodiment of the present invention. However, the present invention is not limited thereto, and any other synthesis method may also be adopted.

[0164] Since the above organometallic complex can emit phosphorescence, it can be used as a light-emitting material or a light-emitting substance of a light-emitting element.

[0165] By using the light-emitting element of an embodiment of the present invention, a light-emitting device, an electronic device, or a lighting device with a long service life can be obtained.

[0166] In the present embodiment, an embodiment of the present invention is described. In other embodiments, other embodiments of the present invention will be described. Note that an embodiment of the present invention is not limited thereto. That is, various embodiments of the invention are described in the present embodiment and other embodiments, and an embodiment of the present invention is not limited to a specific embodiment. For example, although an example of applying an embodiment of the present invention to a light-emitting element is shown in the present embodiment, an embodiment of the present invention is not limited thereto. Depending on the situation, an embodiment of the present invention may also be applied to an object other than a light-emitting element.

[0167] The structure shown in the present embodiment can be appropriately combined with the structure shown in other embodiments and used.

[0168] (Embodiment 2)

[0169] In the present embodiment, the light-emitting element of an embodiment of the present invention described in Embodiment 1 will be described in more detail. Refer to Figure 1A and Figure 1B for description as in Embodiment 1.

[0170] In the light-emitting element shown in this embodiment, an EL layer 102 including a light-emitting layer 113 is provided between a pair of electrodes (a first electrode (anode) 101 and a second electrode (cathode) 103). The EL layer 102 includes a hole injection layer 111, a hole transport layer 112, an electron transport layer 114, an electron injection layer 115, etc. in addition to the light-emitting layer 113.

[0171] The hole injection layer 111 in the EL layer 102 can inject holes into the hole transport layer 112 or the light-emitting layer 113, and can be formed, for example, using a substance with high hole transportability and a substance with acceptability. At this time, electrons are extracted from the substance with high hole transportability by the substance with acceptability, thereby generating holes. Therefore, holes are injected from the hole injection layer 111 through the hole transport layer 112 into the light-emitting layer 113. As the hole injection layer 111, a substance with high hole injectability can also be used. For example, molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, or manganese oxide, etc. can be used. In addition, phthalocyanine compounds such as phthalocyanine (abbreviation: H 2 Pc), copper phthalocyanine (CuPc), etc.; aromatic amine compounds such as 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), etc.; or polymer compounds such as poly(3,4-ethylenedioxythiophene) / poly(styrenesulfonic acid) (PEDOT / PSS) can be used to form the hole injection layer 111.

[0172] Next, a preferred specific example of manufacturing the light-emitting element shown in this embodiment will be described.

[0173] As the first electrode (anode) 101 and the second electrode (cathode) 103, metals, alloys, conductive compounds, and mixtures thereof can be used. Specific examples include indium tin oxide, indium tin oxide containing silicon or silicon oxide, indium zinc oxide, indium oxide containing tungsten and zinc oxide, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium (Ti). In addition, elements belonging to Group 1 or Group 2 of the periodic table can also be used, such as alkali metals like lithium (Li) and cesium (Cs), alkaline earth metals like calcium (Ca) or strontium (Sr), magnesium (Mg), alloys containing these elements (MgAg, AlLi), rare earth metals like europium (Eu) or ytterbium (Yb), alloys containing these elements, and graphene. The first electrode (anode) 101 and the second electrode (cathode) 103 can be formed, for example, by sputtering, evaporation (including vacuum evaporation), etc.

[0174] As substances having high hole transport properties for the hole injection layer 111 and the hole transport layer 112, various organic compounds such as aromatic amine compounds, carbazole derivatives, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. The organic compounds for the composite material are preferably organic compounds with high hole transport properties. Specifically, substances with a hole mobility of 1×10 -6 cm 2 / Vs or more are preferably used. The layer formed using a substance with high hole transport properties is not limited to a single layer, and two or more layers can also be stacked to form it. Hereinafter, organic compounds that can be used as hole transport substances are specifically listed.

[0175] Examples of aromatic amine compounds are: N,N'-bis(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), DNTPD, 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB or α-NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4',4''-tris(carbazol-9-yl)triphenylamine (abbreviation: TCTA), 4,4',4''-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4',4''-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(spiro-9,9'-bifluorene-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), etc.

[0176] Specific examples of carbazole derivatives are: 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-phenylcarbazole (abbreviation: PCzPCN1), etc. Other examples are: 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA), 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene, etc.

[0177] Examples of aromatic hydrocarbons are: 2-tert-butyl-9,10-bis(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-bis(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-bis(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-bis(1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-bis(2-naphthyl)anthracene, 9,9'-bianthracene, 10,10'-diphenyl-9,9'-bianthracene, 10,10'-bis(2-phenylphenyl)-9,9'-bianthracene, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthracene, anthracene, tetracene, rubrene, chrysene, 2,5,8,11-tetra(tert-butyl)chrysene, etc. In addition, pentacene, coronene, etc. can also be used. Particularly preferably, an aromatic hydrocarbon having a hole mobility of 1 × 10 -6 cm 2 / Vs or more and having 14 to 42 carbon atoms is used. The aromatic hydrocarbon may also have a vinyl skeleton. Examples of the aromatic hydrocarbon having a vinyl group include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA), etc.

[0178] 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), poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD), etc. can also be used.

[0179] Examples of the substance having an acceptor property for the hole injection layer 111 and the hole transport layer 112 are 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F 4Compounds having an electron-withdrawing group (halogen group or cyano group) such as (TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), etc. In particular, compounds in which an electron-withdrawing group such as HAT-CN is bonded to a fused aromatic ring having a plurality of heteroatoms are thermally stable, and thus are preferred. Oxides of metals belonging to Groups 4 to 8 of the periodic table can be cited. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferred because they have high electron-accepting properties. Among them, molybdenum oxide is particularly preferred because molybdenum oxide is stable in the atmosphere, has low hygroscopicity, and is easy to handle.

[0180] The light-emitting layer 113 contains a light-emitting substance, which may be a fluorescent light-emitting substance or a phosphorescent light-emitting substance. In the light-emitting element according to one embodiment of the present invention, it is preferable to use the organometallic complex shown in Embodiment 1 as the light-emitting substance in the light-emitting layer 113. The light-emitting layer 113 preferably contains a substance having a triplet excitation energy larger than that of the organometallic complex (guest material) as a host material. In addition to the light-emitting substance, the light-emitting layer 113 may further contain two organic compounds (the two organic compounds may also be any of the above host materials) that can form an exciplex (also referred to as exciplex) when carriers (electrons and holes) recombine in the light-emitting layer 113. In order to efficiently form an exciplex, it is particularly preferable to combine a compound that easily accepts electrons (a material having electron-transporting properties) and a compound that easily accepts holes (a material having hole-transporting properties). When such a combination of a material having electron-transporting properties and a material having hole-transporting properties that form an exciplex is used as the host material, it is easy to optimize the carrier balance between holes and electrons in the light-emitting layer by adjusting the mixing ratio of the material having electron-transporting properties and the material having hole-transporting properties. By optimizing the carrier balance between holes and electrons in the light-emitting layer, it is possible to prevent the region where electrons and holes recombine from existing on one side of the light-emitting layer. By preventing the region where electrons and holes recombine from existing on one side, the reliability of the light-emitting element can be improved.

[0181] As a compound that easily accepts electrons (a material having electron-transporting properties) preferably used in forming the above exciplex, a π-deficient heteroaromatic compound such as a nitrogen-containing heteroaromatic compound or a metal complex can be used. Specific examples include: bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq 2) Metal complexes such as bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviation: BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenol]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviation: ZnBTZ); Heterocyclic compounds with a polyazole skeleton such as 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: OXD-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); Heterocyclic compounds with a diazine skeleton such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenz[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenz[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenz[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenz[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenz[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophen-4-yl)phenyl]dibenz[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothiophenyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm); Heterocyclic compounds with a triazine skeleton such as 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn);and heterocyclic compounds having a pyridine skeleton such as 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tris[3-(pyridin-3-yl)phenyl]benzene (abbreviation: TmPyPB). Among the above materials, heterocyclic compounds having a diazine skeleton, heterocyclic compounds having a triazine skeleton, and heterocyclic compounds having a pyridine skeleton have high reliability, and thus are preferred. In particular, heterocyclic compounds having a diazine (pyrimidine or pyrazine) skeleton and heterocyclic compounds having a triazine skeleton have high electron transport properties and also help to reduce the driving voltage.

[0182] As a compound (a material with hole-transporting properties) that is preferably easy to receive holes when forming the above exciplex, a π-electron-rich heteroaromatic compound (such as a carbazole derivative or an indole derivative) or an aromatic amine compound can be appropriately used. Specific examples include: 2-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), 4,4',4”-tris[N-(1-naphthyl)-N-phenylamino]triphenylamine (abbreviation: 1'-TNATA), 2,7-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-spiro-9,9'-bifluorene (abbreviation: DPA2SF), N,N'-bis(9-phenylcarbazol-3-yl)-N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N-(9,9-dimethyl-2-diphenylamino-9H-fluoren-7-yl)diphenylamine (abbreviation: DPNF), N,N',N”-triphenyl-N,N',N”-tris(9-phenylcarbazol-3-yl)benzene-1,3,5-triamine (abbreviation: PCA3B), 2-[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPASF), N,N'-bis[4-(carbazol-9-yl)phenyl]-N,N'-diphenyl-9,9-dimethylfluorene-2,7-diamine (abbreviation: YGA2F), NPB, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), BSPB, 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), N-(9,9-dimethyl-9H-fluoren-2-yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl-9H-fluoren-2-yl)amino]-9H-fluoren-7-yl}phenylamine (abbreviation: DFLADFL), PCzPCA1, 3-[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA2), DNTPD, 3,6-bis[N-(4-diphenylaminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation: PCzTPN2), PCzPCA2, 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'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluorene-2-amine (abbreviation: PCBASF), N-(4-biphenyl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-carbazol-3-amine (abbreviation: PCBiF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), and other compounds having an aromatic amine skeleton; 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), CBP, 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 9-phenyl-9H-3-(9-phenyl-9H-carbazol-3-yl)carbazole (abbreviation: PCCP), and other compounds having a carbazole skeleton; 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), and other compounds having a thiophene skeleton; and 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), and other compounds having a furan skeleton. Among the above materials, the compounds having an aromatic amine skeleton and the compounds having a carbazole skeleton have high reliability and high hole transportability, and also help to reduce the driving voltage, so they are preferred.

[0183] In addition, when the light-emitting layer 113 contains the above-mentioned organometallic complex (guest material) and a host material, highly efficient phosphorescent emission can be obtained from the light-emitting layer 113.

[0184] In the light-emitting element, the light-emitting layer 113 does not necessarily need to have Figure 1AThe single-layer structure shown may also have a stacked structure including two or more layers as shown in Figure 1B . In this case, each layer in the stack emits light. For example, fluorescence emission is obtained from the first light-emitting layer 113(a1), and phosphorescence emission is obtained from the second light-emitting layer 113(a2) stacked on the first light-emitting layer 113(a1). Note that the stacking order may be the reverse of this. Preferably, luminescence caused by energy transfer from an exciplex to a dopant can be obtained from the layer emitting phosphorescence. The luminescence color of one layer and the luminescence color of another layer may be the same or different. In the case where the luminescence colors are different, for example, a structure can be formed such that blue light can be obtained from one layer and orange light or yellow light etc. can be obtained from another layer. Each layer may also contain a plurality of dopants.

[0185] Note that in the case where the light-emitting layer 113 has a stacked structure, for example, the organometallic complex shown in Embodiment 1, a luminescent substance that converts singlet excitation energy into luminescence, and a luminescent substance that converts triplet excitation energy into luminescence can be used alone or in combination. In this case, for example, the following materials can be used.

[0186] Examples of the luminescent substance that converts singlet excitation energy into luminescence include substances that emit fluorescence (fluorescent compounds).

[0187] Examples of substances that emit fluorescence are 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-diyl-di-4,1-phenylene)bis[N,N',N'-triphenyl-1,4-benzenediamine] (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-benzenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N''' -octaphenyldibenzo[g,p] -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: 2DPABPhA), 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]vinyl}-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)vinyl]-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 (abbreviation: p-mPhAFD), {2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), {2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]vinyl}-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)vinyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), etc.

[0188] Examples of luminescent materials that convert triplet excitation energy into luminescence are substances that emit phosphorescence (phosphorescent compounds) and thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence. Note that the "delayed fluorescence" exhibited by TADF materials refers to luminescence whose spectrum is the same as that of ordinary fluorescence but whose lifetime is very long. This lifetime is 1×10 -6 seconds or more, preferably 1×10 -3 seconds or more.

[0189] Examples of substances that emit phosphorescence are bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridine-N,C 2'}iridium(III) picolinate (abbreviation: [Ir(CF 3 ppy) 2 (pic)]), bis[2-(4',6'-difluorophenyl)pyridine-N,C 2' iridium(III) acetylacetonate (abbreviation: FIr(acac)), tris(2-phenylpyridine)iridium(III) (abbreviation: [Ir(ppy) 3 ), bis(2-phenylpyridine)iridium(III) acetylacetonate (abbreviation: [Ir(ppy) 2 (acac)]), tris(acetylacetonate)(1-phenanthroline)terbium(III) (abbreviation: [Tb(acac) 3 (Phen)]), bis(benzo[h]quinoline)iridium(III) acetylacetonate (abbreviation: [Ir(bzq) 2 (acac)]), bis(2,4-diphenyl-1,3-oxazole-N,C 2' )iridium(III) acetylacetonate (abbreviation: [Ir(dpo) 2 (acac)]), bis{2-[4'-(perfluorophenyl)phenyl]pyridine-N,C 2'}iridium(III) acetylacetonate (abbreviation: [Ir(p-PF-ph) 2 (acac)]), bis(2-phenylbenzothiazole-N,C 2' )iridium(III) acetylacetonate (abbreviation: [Ir(bt) 2 (acac)]), bis[2-(2'-benzo[4,5-α]thienyl)pyridine-N,C 3' iridium(III) acetylacetonate (abbreviation: [Ir(btp) 2 (acac)]), bis(1-phenylisoquinoline-N,C 2' )iridium(III) acetylacetonate (abbreviation: [Ir(piq) 2 (acac)]), (acetylacetonate)bis[2,3-bis(4-fluorophenyl)quinoxaline]iridium(III) (abbreviation: [Ir(Fdpq) 2(acac)), bis(3,5-dimethyl-2-phenylpyrazine)iridium(III) (abbreviation: [Ir(mppr-Me) 2 (acac)), bis(5-isopropyl-3-methyl-2-phenylpyrazine)iridium(III) (abbreviation: [Ir(mppr-iPr) 2 (acac)), bis(2,3,5-triphenylpyrazine)iridium(III) (abbreviation: [Ir(tppr) 2 (acac)), bis(2,3,5-triphenylpyrazine)(dineopentanoyl methane)iridium(III) (abbreviation: [Ir(tppr) 2 (dpm)), bis(6-tert-butyl-4-phenylpyrimidine)iridium(III) (abbreviation: [Ir(tBuppm) 2 (acac)), bis(4,6-diphenylpyrimidine)iridium(III) (abbreviation: [Ir(dppm) 2 (acac)), 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP), tris(1,3-diphenyl-1,3-propanedione)(1,10-phenanthroline)europium(III) (abbreviation: [Eu(DBM) 3 (Phen)), tris[1-(2-thienoyl)-3,3,3-trifluoroacetone](1,10-phenanthroline)europium(III) (abbreviation: [Eu(TTA) 3 (Phen)), etc.

[0190] Examples of TADF materials are fullerenes, their derivatives, acridine derivatives such as proflavine, eosin, etc. Other examples are metal-containing porphyrins such as porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In) or palladium (Pd), etc. Examples of the metal-containing porphyrins are: protoporphyrin-tin fluoride complex (abbreviation: SnF 2 (Proto IX)), mesoporphyrin-tin fluoride complex (abbreviation: SnF 2 (Meso IX)), hematoporphyrin-tin fluoride complex (abbreviation: SnF 2 (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (abbreviation: SnF 2 (Copro III-4Me)), octaethylporphyrin-tin fluoride complex (abbreviation: SnF 2 (OEP)), etioporphyrin-tin fluoride complex (abbreviation: SnF 2 (Etio I)), octaethylporphyrin-platinum chloride complex (abbreviation: PtCl 2such as OEP). In addition, heterocyclic compounds having a π - electron - rich heteroaromatic ring and a π - electron - deficient heteroaromatic ring, such as 2 - (biphenyl - 4 - yl) - 4,6 - bis(12 - phenylindolo[2,3 - a]carbazol - 11 - yl) - 1,3,5 - triazine (abbreviation: PIC - TRZ), can be used. Additionally, a substance in which a π - electron - rich heteroaromatic ring and a π - electron - deficient heteroaromatic ring are directly bonded is particularly preferred because both the donor property of the π - electron - rich heteroaromatic ring and the acceptor property of the π - electron - deficient heteroaromatic ring are enhanced, and the energy difference between S1 and T1 becomes smaller.

[0191] The light - emitting layer 113 can be formed using quantum dots (QD: Quantum Dot) having unique optical properties. Note that QD refers to a semiconductor crystal of nanoscale size. Specifically, the semiconductor crystal of nanoscale size has a diameter of approximately several nm to several tens of nm. In addition, by using crystals of different sizes, the optical properties and electronic properties can be changed, so it is possible to easily adjust the emission color and the like. Since the peak width of the emission spectrum of the quantum dots is narrow, high - color - purity light emission can be obtained.

[0192] Examples of the material constituting the quantum dots include Group 14 elements in the periodic table, Group 15 elements in the periodic table, Group 16 elements in the periodic table, compounds composed of multiple Group 14 elements in the periodic table, compounds composed of elements belonging to Groups 4 to 14 in the periodic table and Group 16 elements in the periodic table, compounds composed of Group 2 elements in the periodic table and Group 16 elements in the periodic table, compounds composed of Group 13 elements in the periodic table and Group 15 elements in the periodic table, compounds composed of Group 13 elements in the periodic table and Group 17 elements in the periodic table, compounds composed of Group 14 elements in the periodic table and Group 15 elements in the periodic table, compounds composed of Group 11 elements in the periodic table and Group 17 elements in the periodic table, iron oxide - based materials, titanium oxide - based materials, chalcogenide spinel - based materials, semiconductor clusters, etc.

[0193] Specific examples include cadmium selenide, cadmium sulfide, cadmium telluride, zinc selenide, zinc oxide, zinc sulfide, zinc telluride, mercury sulfide, mercury selenide, mercury telluride, indium arsenide, indium phosphide, gallium arsenide, gallium phosphide, indium nitride, gallium nitride, indium antimonide, gallium antimonide, aluminum phosphide, aluminum arsenide, aluminum antimonide, lead selenide, lead telluride, lead sulfide, indium selenide, indium telluride, indium sulfide, gallium selenide, arsenic sulfide, arsenic selenide, arsenic telluride, antimony sulfide, antimony selenide, antimony telluride, bismuth sulfide, bismuth selenide, bismuth telluride, silicon, silicon carbide, germanium, tin, selenium, tellurium, boron, carbon, phosphorus, boron nitride, boron phosphide, arsenic boron, aluminum nitride, aluminum sulfide, barium sulfide, barium selenide, barium telluride, calcium sulfide, calcium selenide, calcium telluride, beryllium sulfide, beryllium selenide, beryllium telluride, magnesium sulfide, magnesium selenide, germanium sulfide, germanium selenide, germanium telluride, tin sulfide, tin selenide, tin telluride, lead oxide, copper fluoride, copper chloride, copper bromide, copper iodide, copper oxide, copper selenide, nickel oxide, cobalt oxide, cobalt sulfide, iron oxide, iron sulfide, manganese oxide, molybdenum sulfide, vanadium oxide, tungsten oxide, tantalum oxide, titanium oxide, zirconium oxide, silicon nitride, germanium nitride, aluminum oxide, barium titanate, compounds of selenium, zinc and cadmium, compounds of indium, arsenic and phosphorus, compounds of cadmium, selenium and sulfur, compounds of cadmium, selenium and tellurium, compounds of indium, gallium and arsenic, compounds of indium, gallium and selenium, compounds of indium, selenium and sulfur, compounds of copper, indium and sulfur, and their combinations, etc., but are not limited thereto. In addition, so-called alloy-type quantum dots represented by arbitrary ratios of composition can also be used. For example, alloy-type quantum dots of cadmium, selenium and sulfur are materials effective for obtaining blue light because the emission wavelength can be changed by changing the ratio of elements.

[0194] As the structure of the quantum dots, there are core-type structures, core-shell (Core Shell) type structures, core / multi-shell layer type structures, etc., and any of these structures can be adopted. In addition, core-shell type quantum dots or core / multi-shell layer type quantum dots in which the shell covers the core are preferred because: by using an inorganic material having a wider band gap than the inorganic material used as the core to form the shell, the influence of defects and dangling bonds existing on the surface of the nanocrystal can be reduced, and thus the quantum efficiency of luminescence can be greatly improved.

[0195] In addition, since the QD can be dispersed in a solution, the light-emitting layer 113 can be formed by a coating method, an inkjet method, a printing method, etc. In addition, since the QD can emit light of a bright and distinct color and can emit light in a wide wavelength range, and has high efficiency and a long service life. When the light-emitting layer 113 includes the QD, the device characteristics can be improved.

[0196] The electron transport layer 114 is a layer containing a substance with high electron transportability (also referred to as an electron transport compound). Tris(8-hydroxyquinoline)aluminum (abbreviation: Alq 3 ) and tris(4-methyl-8-hydroxyquinoline)aluminum (abbreviation: Almq 3)、BeBq 2 、BAlq, bis[2-(2-hydroxyphenyl)benzoxazole]zinc (abbreviation: Zn(BOX) 2 )、bis[2-(2-hydroxyphenyl)-benzothiazole]zinc (abbreviation: Zn(BTZ) 2 ) and other metal complexes. In addition, heteroaromatic compounds such as PBD, 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), TAZ, 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen), bathocuproine (abbreviation: BCP), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs) can also be used. Polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy) can also be used. The substances described herein are mainly substances with an electron mobility of 1×10 -6 cm 2 / Vs or more. Note that any substance other than the above substances can be used for the electron transport layer 114 as long as it has higher electron transport properties than hole transport properties.

[0197] The electron transport layer 114 is not limited to a single layer and can also be a laminated structure of two or more layers each containing any of the above substances.

[0198] The electron injection layer 115 is a layer containing a substance with high electron injection properties. The electron injection layer 115 can use lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF 2 ), or alkali metals, alkaline earth metals or their compounds such as lithium oxide (LiO x ). Rare earth metal compounds such as erbium fluoride (ErF 3 ) can also be used. An electride can be used for the electron injection layer 115. Examples of such electrides include substances with a high concentration of electrons added to calcium oxide-aluminum oxide. Any of the substances constituting the electron transport layer 114 described above can be used.

[0199] A composite material formed by mixing an organic compound with an electron donor can be used for the electron injection layer 115. Since this composite material generates electrons in the organic compound by the electron donor, it has excellent electron injection properties and electron transport properties. In this case, the organic compound is preferably a material having excellent performance in transporting the generated electrons. Specifically, for example, the material (metal complex or heteroaromatic compound) constituting the electron transport layer 114 as described above can be used. As the electron donor, a substance that exhibits electron-donating properties with respect to the organic compound can be used. Specifically, alkali metals, alkaline earth metals, or rare earth metals are preferred, and examples include lithium, cesium, magnesium, calcium, erbium, ytterbium, etc. In addition, alkali metal oxides and alkaline earth metal oxides are preferred, and examples include lithium oxide, calcium oxide, barium oxide, etc. A Lewis base such as magnesium oxide can also be used. An organic compound such as tetrathiafulvalene (abbreviation: TTF) can also be used.

[0200] Note that each of the above hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, and electron injection layer 115 can be formed by any one or any combination of the following methods: evaporation method (including vacuum evaporation method), printing method (e.g., relief printing method, intaglio printing method, gravure printing method, lithographic printing method, and screen printing method, etc.), inkjet method, coating method, etc. As the above hole injection layer 111, hole transport layer 112, light-emitting layer 113, electron transport layer 114, and electron injection layer 115, in addition to the above materials, inorganic compounds such as quantum dots or polymer compounds (oligomers, dendrimers, polymers, etc.) can also be used.

[0201] In the above light-emitting element, due to the potential difference applied between the first electrode 101 and the second electrode 103, current flows, and holes and electrons recombine in the EL layer 102, thereby emitting light. Then, this light is extracted to the outside through one or both of the first electrode 101 and the second electrode 103. Therefore, one or both of the first electrode 101 and the second electrode 103 are electrodes having light transmissivity.

[0202] Since the light-emitting element as described above can emit phosphorescence based on an organometallic complex, it can have higher efficiency compared to a light-emitting element that only uses a fluorescent compound.

[0203] The structure shown in this embodiment can be used in appropriate combination with the structures shown in other embodiments.

[0204] (Embodiment 3)

[0205] In this embodiment, a light-emitting element having a plurality of EL layers (hereinafter, referred to as a stacked light-emitting element) according to an embodiment of the present invention will be described.

[0206] The light-emitting element shown in this embodiment is as follows Figure 2A A stacked light-emitting element having a plurality of EL layers (first EL layer 202(1) and second EL layer 202(2)) with a charge generation layer 205 interposed between a pair of electrodes (first electrode 201 and second electrode 204) as shown.

[0207] In this embodiment, the first electrode 201 is used as the anode, and the second electrode 204 is used as the cathode. Additionally, the first electrode 201 and the second electrode 204 may have the same structure as in Embodiment 2. Furthermore, one or both of the plurality of EL layers (first EL layer 202(1) and second EL layer 202(2)) may have the same structure as in Embodiment 2. In other words, the structures of the first EL layer 202(1) and the second EL layer 202(2) may be the same or different. In the case of the same structure, the structure of Embodiment 2 can be applied.

[0208] The charge generation layer 205 provided between the plurality of EL layers (first EL layer 202(1) and second EL layer 202(2)) has the following function: when a voltage is applied to the first electrode 201 and the second electrode 204, electrons are injected into one EL layer, and holes are injected into the other EL layer. In this embodiment, when a voltage is applied such that the potential of the first electrode 201 is higher than that of the second electrode 204, the charge generation layer 205 injects electrons into the first EL layer 202(1) and injects holes into the second EL layer 202(2).

[0209] In addition, from the viewpoint of light extraction efficiency, the charge generation layer 205 preferably has translucency to visible light (specifically, the transmittance of visible light of the charge generation layer 205 is 40% or more). The charge generation layer 205 can function even if its conductivity is less than that of the first electrode 201 or the second electrode 204.

[0210] The charge generation layer 205 may have a structure in which an electron acceptor is added to an organic compound having high hole transportability, or may have a structure in which an electron donor is added to an organic compound having high electron transportability. Alternatively, these two structures may be laminated.

[0211] In the case of adopting a structure in which an electron acceptor is added to an organic compound having high hole transportability, as the organic compound having high hole transportability, a substance having high hole transportability shown as a substance for the hole injection layer 111 and the hole transport layer 112 in Embodiment 2 can be used. For example, aromatic amine compounds such as NPB, TPD, TDATA, MTDATA, BSPB, etc. can be used. The substances described herein mainly have a hole mobility of 1×10 -6 cm 2Note that as long as the hole-transporting property is higher than the electron-transporting property, an organic compound other than the above compounds may be used.

[0212] As the electron acceptor, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F) can be mentioned. 4 -TCNQ), chloranil, etc. Oxides of metals belonging to Groups 4 to 8 in the periodic table can also be cited. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferred because they have high electron accepting properties. Among them, molybdenum oxide is particularly preferred because it is very stable in the atmosphere, has low hygroscopicity, and is easy to handle.

[0213] In the case of adopting a structure in which an electron donor is added to an organic compound with high electron transport properties, the organic compound with high electron transport properties described as the substance for the electron transport layer 114 in Embodiment 2 can be used. For example, a metal complex having a quinoline skeleton or a benzoquinoline skeleton, such as Alq, Almq, etc., can be used. 3 、BeBq 2 , BAlq, etc. In addition, metal complexes with oxazole ligands or thiazole ligands such as Zn(BOX) 2 、Zn(BTZ) 2 In addition to the above metal complexes, PBD, OXD-7, TAZ, BPhen, BCP, etc. can also be used. The substances described here are mainly those with an electron mobility of 1×10 -6 cm 2 In addition, organic compounds other than the above compounds may be used as long as the electron transport property is higher than the hole transport property.

[0214] As the electron donor, an alkali metal, an alkaline earth metal, a rare earth metal, a metal belonging to Group 2 and Group 13 of the periodic table, or an oxide or carbonate thereof can be used. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide, cesium carbonate, etc. are preferably used. In addition, an organic compound such as tetrathianaphthacene can also be used as an electron donor.

[0215] In addition, by forming the charge generation layer 205 using any of the above materials, an increase in the driving voltage caused when laminating the EL layers can be suppressed. The charge generation layer 205 can be formed by any one or any combination of the following methods: evaporation method (including vacuum evaporation method), printing method (e.g., letterpress printing method, gravure printing method, photogravure printing method, lithographic printing method, stencil printing method, etc.), inkjet method, coating method, and the like.

[0216] Although in the present embodiment, a light-emitting element having two EL layers is described, as Figure 2B shown, the present invention can be similarly applied to a light-emitting element in which n (where n is 3 or more) EL layers (202(1) to 202(n)) are laminated. When there are a plurality of EL layers between a pair of electrodes as in the light-emitting element according to the present embodiment, by providing charge generation layers (205(1) to 205(n - 1)) between the EL layers, light emission in a high-brightness region can be achieved while maintaining a low current density. Since a low current density can be maintained, an element with a long service life can be realized.

[0217] When the emission colors of the respective EL layers are different from each other, a desired emission color can be obtained from the entire light-emitting element. For example, in a light-emitting element having two EL layers, when the emission color of the first EL layer and the emission color of the second EL layer are complementary colors, the entire light-emitting element can emit white light. Note that "complementary colors" means colors that can produce achromatic colors when mixed. That is, by mixing complementary color lights, white light emission can be obtained. Specifically, as an example, a combination in which blue light emission is obtained from the first EL layer and yellow or orange light emission is obtained from the second EL layer can be cited. At this time, the blue light emission and the yellow (or orange) light emission do not necessarily have to be both fluorescent light emission or phosphorescent light emission. For example, a combination in which the blue light emission is fluorescent light emission and the yellow (or orange) light emission is phosphorescent light emission or a combination in which the blue light emission is phosphorescent light emission and the yellow (or orange) light emission is fluorescent light emission can also be adopted.

[0218] The same applies to the case of a light-emitting element having three EL layers. For example, when the emission color of the first EL layer is red, the emission color of the second EL layer is green, and the emission color of the third EL layer is blue, the entire light-emitting element can provide white light emission.

[0219] Note that the structure shown in the present embodiment can be used in appropriate combination with the structures shown in other embodiments.

[0220] (Embodiment 4)

[0221] In the present embodiment, a light-emitting device according to an embodiment of the present invention will be described.

[0222] The above-mentioned light-emitting device can be either a passive matrix light-emitting device or an active matrix light-emitting device. Any light-emitting element described in other embodiments can be applied to the light-emitting device shown in this embodiment.

[0223] In this embodiment, first, refer to Figures 3A to 3C to describe the active matrix light-emitting device.

[0224] In addition, Figure 3A is a top view of the light-emitting device, Figure 3B is a cross-sectional view taken along the Figure 3A dotted line A-A' in. The light-emitting device according to this embodiment has a pixel portion 302, a driving circuit portion (source line driving circuit) 303, and driving circuit portions (gate line driving circuits) 304a and 304b provided on an element substrate 301. The pixel portion 302, the driving circuit portion 303, and the driving circuit portions 304a and 304b are sealed between the element substrate 301 and a sealing substrate 306 by a sealing material 305.

[0225] In addition, a surrounding wiring 307 is provided on the element substrate 301. The surrounding wiring 307 is used to connect external input terminals that transmit signals (such as video signals, clock signals, start signals, or reset signals, etc.) or potentials from the outside to the driving circuit portion 303 and the driving circuit portions 304a and 304b. Here, an example of providing a flexible printed circuit (FPC) 308 as an external input terminal is shown. Although only the FPC is illustrated here, the FPC may also be provided with a printed wiring board (PWB). The light-emitting device in this specification includes not only the light-emitting device itself but also the light-emitting device provided with an FPC or a PWB within its scope.

[0226] Next, refer to Figure 3B to describe the cross-sectional structure. A driving circuit portion and a pixel portion are formed on the element substrate 301. Here, the driving circuit portion 303 as the source line driving circuit and the pixel portion 302 are shown.

[0227] The driving circuit portion 303 is an example of a combination of FET309 and FET310. In addition, the driving circuit portion 303 can be formed of a circuit including a unipolar transistor (n-channel transistor or p-channel transistor), or can be formed of a CMOS circuit including an n-channel transistor and a p-channel transistor. Although the driver integrated type in which the driving circuit is formed on the substrate is shown in this embodiment, the driving circuit does not necessarily have to be formed on the substrate and can also be formed outside the substrate.

[0228] The pixel section 302 includes a switching FET (not shown) and a current control FET 312. The wiring (source electrode or drain electrode) of the current control FET 312 is electrically connected to the first electrodes (anodes) (313a and 313b) of the light-emitting elements 317a and 317b. Although the pixel section 302 includes two types of FETs (a switching FET and a current control FET 312) in this embodiment, one embodiment of the present invention is not limited thereto. For example, the pixel section 302 may also include a combination of three or more FETs and capacitors.

[0229] As the FETs 309, 310, and 312, for example, staggered transistors or anti-staggered transistors can be used. Examples of semiconductor materials that can be used for the FETs 309, 310, and 312 include group 13 semiconductors, group 14 semiconductors (such as silicon), compound semiconductors, oxide semiconductors, and organic semiconductors. In addition, there is no particular limitation on the crystallinity of the semiconductor material, and amorphous semiconductors or crystalline semiconductors can be used. In particular, the FETs 309, 310, and 312 preferably use oxide semiconductors. Examples of oxide semiconductors are In-Ga oxides, In-M-Zn oxides (where M is Al, Ga, Y, Zr, La, Ce, Hf, or Nd), etc. As the FETs 309, 310, and 312, for example, an oxide semiconductor having a bandgap of 2 eV or more, preferably 2.5 eV or more, and more preferably 3 eV or more is used, whereby the off-state current of the transistor can be reduced.

[0230] In addition, a conductive film (320a, 320b) for optical adjustment is laminated on the first electrodes (313a, 313b). For example, as Figure 3B shown, when the wavelengths of the light extracted from the light-emitting element 317a and the light extracted from the light-emitting element 317b are different from each other, the thicknesses of the conductive films 320a and 320b are different from each other. In addition, an insulator 314 is formed so as to cover the ends of the first electrodes (313a, 313b). In this embodiment, the insulator 314 is formed using a positive photosensitive acrylic resin. In this embodiment, the first electrodes (313a, 313b) are used as anodes.

[0231] The insulator 314 preferably includes a surface having a curvature at its upper end or lower end. Therefore, the coverage of the film formed on the insulator 314 can be improved. For example, the insulator 314 can be formed using a negative photosensitive resin or a positive photosensitive resin. The material for the insulator 314 is not limited to organic compounds, and inorganic compounds such as silicon oxide, silicon oxynitride, and silicon nitride can also be used.

[0232] An EL layer 315 and a second electrode 316 are stacked on the first electrodes (313a, 313b). At least a light-emitting layer is provided in the EL layer 315. In a light-emitting element (317a, 317b) including the first electrodes (313a, 313b), the EL layer 315, and the second electrode 316, an end portion of the EL layer 315 is covered by the second electrode 316. The structure of the EL layer 315 may be the same as or different from the single-layer structure and the stacked structure shown in Embodiments 2 and 3. Also, the above structure may be different between the respective light-emitting elements.

[0233] As the first electrodes (313a, 313b), the EL layer 315, and the second electrode 316, any of the materials shown in Embodiment 2 can be used. The first electrodes (313a, 313b) of the light-emitting elements (317a, 317b) are electrically connected to the surrounding wiring 307 in the region 321, and thus an external signal is input through the FPC 308. The second electrode 316 of the light-emitting elements (317a, 317b) is electrically connected to the surrounding wiring 323 in the region 322, and thus an external signal is input through an FPC 308 (not shown).

[0234] Although only two light-emitting elements (317a, 317b) are shown in the cross-sectional view Figure 3B shown, a plurality of light-emitting elements are arranged in a matrix in the pixel portion 302. Specifically, in the pixel portion 302, light-emitting elements that emit light of two colors (e.g., B, Y), light-emitting elements that emit light of three colors (e.g., R, G, B), light-emitting elements that emit light of four colors (e.g., (R, G, B, Y) or (R, G, B, W), etc.) are formed, whereby a light-emitting device capable of full-color display can be obtained. In these cases, full-color display is achieved in the following manner: using materials different according to the emission color of the light-emitting element or the like to form a light-emitting layer (so-called separate coating formation), or a plurality of light-emitting elements may share a single light-emitting layer formed of the same material and also include a color filter. Thus, by combining the light-emitting elements that emit light of various colors as described above, effects such as improvement in color purity and reduction in power consumption can be obtained. Furthermore, the luminous efficiency of the light-emitting device can be improved and its power consumption can be reduced by combining with quantum dots.

[0235] By attaching the sealing substrate 306 to the element substrate 301 using the sealing material 305, the light-emitting elements 317a, 317b are provided in a space 318 surrounded by the element substrate 301, the sealing substrate 306, and the sealing material 305.

[0236] The sealed substrate 306 is provided with a colored layer (color filter) 324, and a black layer (black matrix) 325 is provided between adjacent colored layers. Note that one or both of the adjacent colored layers (color filters) 324 may be provided in a manner that partially overlaps with the black layer (black matrix) 325. The light emitted from the light-emitting elements 317a and 317b is extracted to the outside through the colored layer (color filter) 324.

[0237] In addition, the space 318 may be filled with an inert gas (such as nitrogen or argon) or a sealing material 305. When applying the sealing material to bond the substrates, it is preferable to perform one or more of UV treatment or heat treatment.

[0238] It is preferable to use an epoxy resin or glass powder for the sealing material 305. Preferably, these materials do not allow moisture or oxygen to pass through as much as possible. As the sealed substrate 306, a glass substrate, a quartz substrate, or a plastic substrate made of FRP (fiber reinforced plastic), PVF (polyvinyl fluoride), polyester, acrylic resin, etc. can be used. In order to achieve high adhesiveness, when using glass powder as the sealing material, the element substrate 301 and the sealed substrate 306 are preferably glass substrates.

[0239] The structure of the FET electrically connected to the light-emitting element can be different in terms of the position of the gate electrode, that is, the same as the structure of the FETs 326, 327, and 328 shown Figure 3B Here, that is, the same as Figure 3C shown. The colored layer (color filter) 324 provided on the sealed substrate 306 can also be arranged as shown Figure 3C in such a way that the colored layer (color filter) 324 also overlaps with an adjacent colored layer (color filter) 324 at the position where the colored layer (color filter) 324 overlaps with the black layer (black matrix) 325.

[0240] As described above, an active matrix light-emitting device can be obtained.

[0241] The light-emitting device according to an embodiment of the present invention may be a passive matrix light-emitting device instead of the above-described active matrix light-emitting device.

[0242] Figure 4A and Figure 4B show a passive matrix light-emitting device. Figure 4A is a top view of the passive matrix light-emitting device, Figure 4B and is a cross-sectional view of the passive matrix light-emitting device.

[0243] As shown in Figure 4A and Figure 4BAs shown, a light-emitting element 405 including a first electrode 402, an EL layer (403a, 403b, 403c), and a second electrode 404 is formed on a substrate 401. Further, the first electrode 402 is island-shaped, and a plurality of first electrodes 402 are formed in a stripe shape in one direction ( Figure 4A the horizontal direction in the figure). An insulating film 406 is formed on a part of the first electrode 402. A partition wall 407 formed of an insulating material is provided on the insulating film 406. The side walls of the partition wall 407 are Figure 4B such that the distance between one side wall and the other side wall gradually decreases as it approaches the substrate surface, as shown.

[0244] Since the insulating film 406 has an opening in a part of the first electrode 402, an EL layer (403a, 403b, 403c) and a second electrode 404 divided into a desired shape can be formed on the first electrode 402. In Figure 4A and Figure 4B the example, a mask such as a metal mask and the partition wall 407 on the insulating film 406 are used to form the EL layer (403a, 403b, 403c) and the second electrode 404. In this example, the EL layer 403a, the EL layer 403b, and the EL layer 403c emit light of different colors (for example, red, green, blue, yellow, orange, white, etc.).

[0245] After the EL layer (403a, 403b, 403c) is formed, the second electrode 404 is formed. Therefore, the second electrode 404 is formed on the EL layer (403a, 403b, 403c) so as not to contact the first electrode 402.

[0246] Note that sealing can be performed in the same manner as in the case of an active matrix light-emitting device, so the description thereof is omitted.

[0247] As described above, a passive matrix light-emitting device can be obtained.

[0248] For example, in this specification and the like, various substrates can be used to form transistors or light-emitting elements. There is no particular limitation on the type of substrate. As such a substrate, for example, a semiconductor substrate (e.g., a single crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate having a stainless steel foil, a tungsten substrate, a substrate having a tungsten foil, a flexible substrate, a laminated film, paper containing a fibrous material, or a base film, etc. can be used. As an example of the glass substrate, a barium borosilicate glass substrate, an aluminosilicate glass substrate, or a soda-lime glass substrate, etc. can be cited. Examples of the flexible substrate, the laminated film, the base film, etc. are plastic substrates typified by polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), and polytetrafluoroethylene (PTFE). Other examples are synthetic resins such as acrylic resin. Or, polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, etc. can be used. Or, polyamide, polyimide, aromatic polyamide, epoxy, an inorganic vapor deposition film, or paper, etc. can be used. In particular, by using a semiconductor substrate, a single crystal substrate, or an SOI substrate, etc., small transistors with little non-uniformity in characteristics, dimensions, or shape, etc. and high current supply ability can be manufactured. The use of the circuits of the above transistors enables low power consumption or high integration of the circuits.

[0249] In addition, a flexible substrate can also be used as the substrate, and transistors or light-emitting elements can be directly formed on the flexible substrate. Or, a release layer can be provided between the substrate and the transistors or light-emitting elements. The release layer can be used when a part or all of the semiconductor device formed on the release layer is separated from the substrate and transferred to another substrate. At this time, the transistors or light-emitting elements can also be transferred to a substrate with low heat resistance or a flexible substrate. As the above release layer, for example, a laminate of an inorganic film including a tungsten film and a silicon oxide film or an organic resin film such as polyimide formed on the substrate can be used.

[0250] That is to say, a certain substrate can also be used to form transistors or light-emitting elements, and then the transistors or light-emitting elements can be transferred to another substrate. Examples of the substrate to which the transistors or light-emitting elements are transferred are not only the above substrates on which transistors or light-emitting elements can be formed, but also a paper substrate, a glassine paper substrate, an aromatic polyamide film substrate, a polyimide film substrate, a stone substrate, a wood substrate, a cloth substrate (including natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polyester), or regenerated fibers (acetate fiber, cuprammonium fiber, rayon, regenerated polyester), etc.), a leather substrate, a rubber substrate, etc. When using the above substrates, transistors with good characteristics or low power consumption can be formed, devices that are not easily damaged or have high heat resistance can be provided, or reduction in weight and thickness can be achieved.

[0251] In addition, the structure shown in this embodiment can be used in appropriate combination with the structures shown in other embodiments.

[0252] (Embodiment 5)

[0253] In this embodiment, examples of various electronic devices and automobiles manufactured using a light-emitting device according to an embodiment of the present invention will be described.

[0254] Examples of electronic devices including a light-emitting device are a television device (also referred to as a TV or a television receiver), a display for a computer or the like, a camera such as a digital camera and a digital video camera, a digital photo frame, a mobile phone (also referred to as a mobile telephone, a mobile phone device), a portable game machine, a portable information terminal, an audio reproduction device, a large game machine such as a pachinko machine, and the like. Figure 5A , Figure 5B , Figure 5C , Figure 5D , Figure 5D’-1 and Figure 5D’-2 as well as Figures 6A to 6C show specific examples of these electronic devices.

[0255] Figure 5A Shows an example of a television device. In the television device 7100, a display unit 7103 is assembled in a housing 7101. The display unit 7103 can display an image and may be a touch screen (input / output device) provided with a touch sensor (input device). In addition, a light-emitting device according to an embodiment of the present invention can be used for the display unit 7103. Further, here, the housing 7101 is supported by a bracket 7105.

[0256] The television device 7100 can be operated by using an operation switch of the housing 7101 or a separately provided remote controller 7110. By using the operation keys 7109 of the remote controller 7110, operations such as channel and volume can be performed, and the image displayed on the display unit 7103 can be operated. In addition, the remote controller 7110 may be provided with a display unit 7107 for displaying data output from the remote controller 7110.

[0257] In addition, the television device 7100 is provided with a receiver, a modem, and the like. General television broadcasts can be received by using the receiver. Further, when the television device is connected to a communication network in a wired or wireless manner through a modem, one-way (from a sender to a receiver) or two-way (between a sender and a receiver or between receivers, etc.) information communication can be performed.

[0258] Figure 5BA computer is shown, which includes a main body 7201, a housing 7202, a display unit 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, etc. Note that the computer can be manufactured by using the light-emitting device of an embodiment of the present invention for the display unit 7203. The display unit 7203 can also be a touch screen (input / output device) equipped with a touch sensor (input device).

[0259] Figure 5C A smartwatch is shown, which includes a housing 7302, a display unit 7304, operation buttons 7311 and 7312, connection terminals 7313, a watch band 7321, a watch band buckle 7322, etc.

[0260] The display unit 7304 installed in the housing 7302 used as a frame has a non-rectangular display area. The display unit 7304 can display an icon 7305 representing time and other icons 7306, etc. The display unit 7304 can also be a touch screen (input / output device) equipped with a touch sensor (input device).

[0261] Figure 5C The shown smartwatch can have various functions. For example, it can have the following functions: the function of displaying various information (static images, moving images, text images, etc.) on the display unit; the touch screen function; the function of displaying a calendar, date, or time, etc.; the function of controlling processing with various software (programs); the wireless communication function; the function of connecting to various computer networks using the wireless communication function; the function of sending and receiving various data using the wireless communication function; and the function of reading a program or data stored in a recording medium and displaying the program or data on the display unit, etc.

[0262] The housing 7302 can include a speaker, a sensor (a sensor having the function of measuring factors such as force, displacement, position, speed, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, inclination, vibration, odor, or infrared rays), a microphone, etc. In addition, the smartwatch can be manufactured by using the light-emitting device for the display unit 7304.

[0263] Figure 5D An example of a mobile phone (e.g., a smartphone) is shown. The mobile phone 7400 includes a display unit 7402, a microphone 7406, a speaker 7405, a camera 7407, an external connection part 7404, operation buttons 7403, etc. in a housing 7401. When manufacturing the light-emitting device by forming a light-emitting element of an embodiment of the present invention on a flexible substrate, the light-emitting device can be used for a display unit 7402 having a curved surface as Figure 5D shown.

[0264] When touching the display unit 7402 of the mobile phone 7400 shown with a finger or the like Figure 5D data can be input to the mobile phone 7400. In addition, operations such as making a call or writing an email can be performed by touching the display unit 7402 with a finger or the like.

[0265] There are mainly the following three screen modes for the display unit 7402. The first mode is a display mode mainly for image display. The second mode is an input mode mainly for inputting data such as text. The third mode is a display-input mode that combines the display mode and the input mode.

[0266] For example, in the case of making a call or writing an email, the display unit 7402 is set to a text input mode mainly for text input, so that the text displayed on the screen can be input. In this case, preferably, a keyboard or number buttons are displayed on most of the screen of the display unit 7402.

[0267] When detection devices such as a gyro sensor and an acceleration sensor are provided inside the mobile phone 7400, the direction of the mobile phone 7400 (whether the mobile phone is in a longitudinal configuration or a horizontal configuration suitable for the landscape mode or the portrait mode) is judged, and thus the screen display of the display unit 7402 can be automatically switched.

[0268] The screen mode is switched by touching the display unit 7402 or operating the operation buttons 7403 of the housing 7401. The screen mode can be switched according to the type of image displayed on the display unit 7402. For example, when the signal of the image displayed on the display unit is a signal of dynamic image data, the screen mode is switched to the display mode. When the image signal is a signal of text data, the screen mode is switched to the input mode.

[0269] In addition, in the input mode, if the signal detected by the light sensor of the display unit 7402 is detected and no input is made by touching the display unit 7402 within a certain time, the screen mode can also be controlled to switch from the input mode to the display mode.

[0270] The display unit 7402 can also be used as an image sensor. For example, by touching the display unit 7402 with a palm or a finger, palm prints, fingerprints, etc. can be photographed for personal identification. In addition, a backlight that emits near-infrared light or a light source for sensing that emits near-infrared light can be used for the display unit to photograph finger veins, palm veins, etc.

[0271] A light-emitting device can be used for other structures of a mobile phone (for example, a smart phone) having Figure 5D’-1 or Figure 5D’-2 the structure shown.

[0272] Note that in a mobile phone having the Figure 5D’-1 or Figure 5D’-2 shown structure, text data, image data, etc. are displayed not only on the first surfaces 7501(1) and 7501(2) of the housing 7500(1) and the housing 7500(2), but also on the second surfaces 7502(1) and 7502(2). With this structure, the user can easily confirm the text data, image data, etc. displayed on the second surfaces 7502(1), 7502(2), etc. in a state where the mobile phone is stored in the user's upper body pocket.

[0273] Other electronic devices including a light-emitting device are Figures 6A to 6C the foldable portable information terminal shown. Figure 6A The portable information terminal 9310 in the unfolded state is shown. Figure 6B The portable information terminal 9310 when being unfolded or folded is shown. Figure 6C The portable information terminal 9310 in the folded state is shown. The portable information terminal 9310 has good portability in the folded state. The portable information terminal 9310 has a strong overview in the unfolded state because it has a large display area with seamless splicing.

[0274] The display unit 9311 is supported by three housings 9315 connected by a hinge 9313. In addition, the display unit 9311 can also be a touch screen (input / output device) equipped with a touch sensor (input device). By bending the display unit 9311 through the connection part between the two housings 9315 using the hinge 9313, the portable information terminal 9310 can be reversibly deformed from the unfolded state to the folded state. The light-emitting device of an embodiment of the present invention can be used for the display unit 9311. The display area 9312 in the display unit 9311 is the display area located on the side of the portable information terminal 9310 in the folded state. Information icons or shortcuts of frequently used application software or programs can be displayed on the display area 9312, and information confirmation and startup of application software, etc. can be smoothly performed.

[0275] Figure 7A and Figure 7B A car including a light-emitting device is shown. The light-emitting device can be included in the car. Specifically, the light-emitting device can be included in Figure 7A the lights 5101 on the outside of the car shown (including the lights at the rear of the vehicle body), the wheel hubs 5102 of the tires, a part or the whole of the door 5103, etc. The light-emitting device can be included in Figure 7BThe display unit 5104, steering wheel 5105, gear lever 5106, seat 5107, interior rearview mirror 5108, etc. on the inner side of the vehicle shown, or a part of the glass window.

[0276] As described above, an electronic device and a vehicle can be obtained by using the light-emitting device according to an embodiment of the present invention. In addition, the light-emitting device can be used for electronic devices and vehicles in various fields, not limited to the electronic devices and vehicles shown in this embodiment.

[0277] In addition, the structure shown in this embodiment can be used in appropriate combination with the structure shown in other embodiments.

[0278] (Embodiment 6)

[0279] In this embodiment, with reference to Figures 8A to 8D The structure of a lighting device manufactured using a light-emitting element according to an embodiment of the present invention will be described.

[0280] Figures 8A to 8D is an example of a cross-sectional view of the lighting device. Figure 8A and Figure 8B show a bottom-emitting type lighting device that extracts light from the substrate side, while Figure 8C and Figure 8D show a top-emitting type lighting device that extracts light from the sealing substrate side.

[0281] Figure 8A The lighting device 4000 shown includes a light-emitting element 4002 on a substrate 4001. In addition, the lighting device 4000 includes a substrate 4003 with irregularities outside the substrate 4001. The light-emitting element 4002 includes a first electrode 4004, an EL layer 4005, and a second electrode 4006.

[0282] The first electrode 4004 is electrically connected to the electrode 4007, and the second electrode 4006 is electrically connected to the electrode 4008. In addition, an auxiliary wiring 4009 electrically connected to the first electrode 4004 may be provided. Further, an insulating layer 4010 is formed on the auxiliary wiring 4009.

[0283] The substrate 4001 and the sealing substrate 4011 are bonded by a sealing material 4012. It is preferable to provide a desiccant 4013 between the sealing substrate 4011 and the light-emitting element 4002. Since the substrate 4003 has irregularities as Figure 8A shown, the extraction efficiency of the light emitted from the light-emitting element 4002 can be improved.

[0284] As Figure 8B shown in the lighting device 4100, a diffusion plate 4015 may be provided outside the substrate 4001 instead of the substrate 4003.

[0285] Figure 8C The lighting device 4200 shown includes a light-emitting element 4202 on a substrate 4201. The light-emitting element 4202 includes a first electrode 4204, an EL layer 4205, and a second electrode 4206.

[0286] The first electrode 4204 is electrically connected to an electrode 4207, and the second electrode 4206 is electrically connected to an electrode 4208. An auxiliary wiring 4209 electrically connected to the second electrode 4206 can be provided. An insulating layer 4210 can be provided under the auxiliary wiring 4209.

[0287] The substrate 4201 and a sealing substrate 4211 having irregularities are bonded by a sealing material 4212. A barrier film 4213 and a planarization film 4214 can be provided between the sealing substrate 4211 and the light-emitting element 4202. Since the sealing substrate 4211 has irregularities as Figure 8C shown, the extraction efficiency of the light emitted from the light-emitting element 4202 can be improved.

[0288] As Figure 8D shown in the lighting device 4300, a diffusion plate 4215 can also be provided on the light-emitting element 4202 instead of the sealing substrate 4211.

[0289] The EL layers 4005, 4205 of the present embodiment can include an organometallic complex of an embodiment of the present invention. In this case, a lighting device with low power consumption can be provided.

[0290] In addition, the structure shown in the present embodiment can be used in appropriate combination with the structures shown in other embodiments.

[0291] (Embodiment 7)

[0292] In the present embodiment, an example of a lighting device using a light-emitting device of an embodiment of the present invention will be described with reference to Figure 9 one example.

[0293] Figure 9 An example of using the light-emitting device as an indoor lighting device 8001 is shown. Since the light-emitting device can have a large area, it can also be used for a large-area lighting device. In addition, by using a housing having a curved surface, a lighting device 8002 having a curved light-emitting area can be obtained. Since the light-emitting element included in the light-emitting device shown in the present embodiment is in a thin film form, the degree of freedom in housing design is higher. Therefore, a lighting device capable of various delicate designs can be formed. Furthermore, a lighting device 8003 can also be provided on the wall surface of the room.

[0294] In addition to the above examples, when the light-emitting device is used as a part of indoor furniture, a lighting device used as furniture can be obtained.

[0295] As described above, various lighting devices including the light-emitting device can be obtained. In addition, these lighting devices are also an embodiment of the present invention.

[0296] The structure shown in this embodiment can be used in appropriate combination with the structures shown in other embodiments.

[0297] (Embodiment 8)

[0298] In this embodiment, with reference to Figure 10A and Figure 10B 、 Figure 11A and Figure 11B 、 Figure 12A and Figure 12B 、 Figure 13A and Figure 13B and Figure 14 a touch screen including a light-emitting element according to an embodiment of the present invention or a light-emitting device according to an embodiment of the present invention will be described.

[0299] Figure 10A and Figure 10B are perspective views of the touch screen 2000. Note that in Figure 10A and Figure 10B , for easy understanding, only the main components of the touch screen 2000 are shown.

[0300] The touch screen 2000 includes a display panel 2501 and a touch sensor 2595 (see Figure 10B ). The touch screen 2000 has a substrate 2510, a substrate 2570, and a substrate 2590.

[0301] The display panel 2501 includes a plurality of pixels and a plurality of wirings 2511 for supplying signals to the pixels on the substrate 2510. The plurality of wirings 2511 are led to the outer peripheral portion of the substrate 2510, and a part of the plurality of wirings 2511 constitutes a terminal 2519. The terminal 2519 is electrically connected to the FPC 2509(1).

[0302] The substrate 2590 includes a touch sensor 2595 and a plurality of wirings 2598 electrically connected to the touch sensor 2595. The plurality of wirings 2598 are led to the outer peripheral portion of the substrate 2590, and a part of the plurality of wirings 2598 constitutes a terminal 2599. The terminal 2599 is electrically connected to the FPC 2509(2). In addition, for easy understanding, in Figure 10B , the electrodes and wirings of the touch sensor 2595 provided on the back side (the side opposite to the substrate 2510) of the substrate 2590 are shown by solid lines.

[0303] As the touch sensor 2595, for example, a capacitive touch sensor can be used. Examples of the capacitive touch sensor include a surface capacitive touch sensor, a projected capacitive touch sensor, etc.

[0304] Examples of the projected capacitive touch sensor are a self-capacitive touch sensor, a mutual-capacitive touch sensor, etc., which are mainly distinguished according to the difference in the driving method. Preferably, a mutual-capacitive touch sensor is used because multi-point detection can be performed simultaneously.

[0305] First, refer to Figure 10B An example of using a projected capacitive touch sensor will be described. Note that in the case of a projected capacitive touch sensor, various sensors capable of detecting the approach or contact of a detection object such as a finger can be used.

[0306] The projected capacitive touch sensor 2595 has an electrode 2591 and an electrode 2592. The electrode 2591 is electrically connected to any one of a plurality of wirings 2598, and the electrode 2592 is electrically connected to any other one of the plurality of wirings 2598. As Figure 10A and Figure 10B shown, each of the electrodes 2592 has the following shape: A plurality of quadrilaterals are arranged in one direction in such a way that a corner of one quadrilateral is connected to a corner of another quadrilateral through a wiring 2594. Each of the electrodes 2591 also has a shape in which a plurality of quadrilaterals are arranged in such a way that a corner of one quadrilateral is connected to a corner of another quadrilateral, but the connection direction of the electrode 2591 is a direction crossing the connection direction of the electrode 2592. Note that the connection direction of the electrode 2591 and the connection direction of the electrode 2592 do not necessarily need to be perpendicular, and the electrode 2591 can also be arranged in such a way that it crosses the electrode 2592 at an angle greater than 0 degrees and less than 90 degrees.

[0307] Preferably, the area of the crossing portion of the wiring 2594 and the electrode 2592 is minimized. Due to the above structure, the area of the region where no electrode is provided can be reduced, thereby reducing the non-uniformity of the transmittance. As a result, the luminance non-uniformity of the light transmitted through the touch sensor 2595 can be reduced.

[0308] In addition, the shapes of the electrodes 2591 and 2592 are not limited to this, and they can have various shapes. For example, a plurality of electrodes 2591 can also be arranged in such a way that the gap between the electrodes 2591 is minimized, and a plurality of electrodes 2592 are provided in such a way that an insulating layer is interposed between the electrodes 2591 and 2592. At this time, preferably, a virtual electrode electrically insulated from these electrodes is provided between two adjacent electrodes 2592, so that the area of the region where the transmittance is different can be reduced.

[0309] Next, refer to Figure 11A and Figure 11BA detailed description of the touch screen 2000 will be given. Figure 11A and Figure 11B is equivalent to a cross-sectional view along the Figure 10A dotted line X1-X2 shown.

[0310] The touch screen 2000 includes a touch sensor 2595 and a display panel 2501.

[0311] The touch sensor 2595 includes electrodes 2591 and 2592 arranged in a staggered shape in contact with a substrate 2590, an insulating layer 2593 covering the electrodes 2591 and 2592, and a wiring 2594 that electrically connects adjacent electrodes 2591. An electrode 2592 is provided between adjacent electrodes 2591.

[0312] The electrodes 2591 and 2592 can be formed using a transparent conductive material. As the transparent conductive material, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zinc oxide doped with gallium can be used. Similarly, a graphene compound can also be used. When using a graphene compound, for example, it can be formed by reducing a graphene oxide film. As the reduction method, a method of heating or a method of irradiating a laser can be adopted.

[0313] For example, the electrodes 2591 and 2592 can be formed by depositing a transparent conductive material on the substrate 2590 using a sputtering method and then removing unnecessary portions by various patterning techniques such as photolithography.

[0314] Examples of materials for the insulating layer 2593 include resins such as acrylic resin or epoxy resin, resins having a siloxane bond, and inorganic insulating materials such as silicon oxide, silicon oxynitride, or aluminum oxide.

[0315] Adjacent electrodes 2591 are electrically connected due to the wiring 2594 formed in a part of the insulating layer 2593. In addition, the material for the wiring 2594 preferably has higher conductivity than the materials for the electrodes 2591 and 2592 to reduce resistance.

[0316] The wiring 2598 is electrically connected to the electrode 2591 or the electrode 2592. A part of the wiring 2598 is used as a terminal. The wiring 2598 can be made of a metal material such as aluminum, gold, platinum, silver, nickel, titanium, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or an alloy material containing any of these metal materials.

[0317] The wiring 2598 is electrically connected to the FPC 2509(2) through a terminal 2599. The terminal 2599 can be any of various anisotropic conductive films (ACF), anisotropic conductive pastes (ACP), etc.

[0318] An adhesive layer 2597 is provided in contact with the wiring 2594. In other words, the touch sensor 2595 is bonded in a manner overlapping the display panel 2501 with the adhesive layer 2597 interposed therebetween. Further, a substrate 2570 may be provided on the surface of the display panel 2501 in contact with the adhesive layer 2597 as Figure 11A shown, but the substrate 2570 is not necessarily required.

[0319] The adhesive layer 2597 has translucency. For example, a thermosetting resin or an ultraviolet curable resin may be used. Specifically, resins such as acrylic resins, urethane resins, epoxy resins, or silicone resins may be used.

[0320] Figure 11A The display panel 2501 shown includes a plurality of pixels and drive circuits arranged in a matrix between the substrate 2510 and the substrate 2570. Each pixel includes a light emitting element and a pixel circuit for driving the light emitting element.

[0321] In Figure 11A as an example of a pixel of the display panel 2501, a pixel 2502R is shown, and as an example of a drive circuit, a scan line drive circuit 2503g is shown.

[0322] The pixel 2502R includes a light emitting element 2550R and a transistor 2502t capable of supplying power to the light emitting element 2550R.

[0323] An insulating layer 2521 covers the transistor 2502t. The insulating layer 2521 has a function of covering irregularities due to formed transistors and the like to achieve a flat surface. The insulating layer 2521 may also be used as a layer for preventing impurity diffusion. Since it can prevent a decrease in the reliability of transistors and the like due to impurity diffusion, it is preferable.

[0324] The light emitting element 2550R is electrically connected to the transistor 2502t through wiring. One electrode of the light emitting element 2550R is directly connected to the wiring. The end portion of one electrode of the light emitting element 2550R is covered by an insulator 2528.

[0325] The light emitting element 2550R includes an EL layer between a pair of electrodes. A coloring layer 2567R is provided to overlap the light emitting element 2550R, and a part of the light emitted by the light emitting element 2550R passes through the coloring layer 2567R and is emitted in the direction indicated by an arrow in the drawing. A light shielding layer 2567BM is provided at the end portion of the coloring layer, and a sealing layer 2560 is included between the light emitting element 2550R and the coloring layer 2567R.

[0326] Note that when a sealing layer 2560 is provided on the side where light from the light-emitting element 2550R is extracted, the sealing layer 2560 preferably has light transmittance. The refractive index of the sealing layer 2560 is preferably higher than that of air.

[0327] The scan line driving circuit 2503g includes a transistor 2503t and a capacitor 2503c. In addition, the driving circuit and the pixel circuit can be formed on the same substrate through the same process. Therefore, similarly to the transistor 2502t of the pixel circuit, the transistor 2503t of the driving circuit (scan line driving circuit 2503g) is also covered with an insulating layer 2521.

[0328] There is a wiring 2511 capable of supplying a signal to the transistor 2503t. A terminal 2519 is provided in contact with the wiring 2511. The terminal 2519 is electrically connected to the FPC 2509(1), and the FPC 2509(1) has a function of supplying signals such as an image signal and a synchronization signal. Note that a printed wiring board (PWB) can also be attached to the FPC 2509(1).

[0329] Although Figure 11A the illustrated display panel 2501 includes a bottom-gate transistor, the structure of the transistor is not limited thereto, and any transistor having various structures can also be used. In Figure 11A each of the illustrated transistors 2502t and 2503t, a semiconductor layer containing an oxide semiconductor can be used as the channel region. In addition, a semiconductor layer containing amorphous silicon or a semiconductor layer containing polycrystalline silicon crystallized by a process such as laser annealing can also be used as the channel region.

[0330] Figure 11B The structure of a display panel 2501 including a top-gate transistor instead of Figure 11A the illustrated bottom-gate transistor is shown. The type of semiconductor layer that can be used for the channel region does not depend on the structure of the transistor.

[0331] In Figure 11A the illustrated touch panel 2000, as Figure 11A shown, it is preferable to provide an antireflection layer 2567p overlapping at least with the pixels on the surface on the side where light from the pixels is extracted of the touch panel. As the antireflection layer 2567p, a circular polarizing plate or the like can be used.

[0332] As Figure 11A the illustrated substrates 2510, 2570, and 2590, for example, a water vapor transmission rate of 1 × 10 -5 g / (m 2 ·day) or less can be used, and preferably 1 × 10 -6 g / (m 2· Flexible materials with a thickness of less than (a certain value) days. Additionally, materials that make the thermal expansion coefficients of these substrates approximately the same are preferably used. For example, the linear expansion coefficient of this material is 1×10 -3 / K or less, preferably 5×10 -5 / K or less, more preferably 1×10 -5 / K or less.

[0333] Next, with reference to Figure 12A and Figure 12B a touch screen 2000' having a structure different from that of the touch screen 2000 shown in Figure 11A and Figure 11B will be described. The touch screen 2000' can be used as a touch screen in the same way as the touch screen 2000.

[0334] Figure 12A and Figure 12B are cross-sectional views of the touch screen 2000'. Figure 12A and Figure 12B The difference between the touch screen 2000' shown in Figure 11A and Figure 11B and the touch screen 2000 shown in

[0335] is the position of the touch sensor 2595 relative to the display panel 2501. Only the different structures will be described, and for other identical structures, the description of the above touch screen 2000 will be cited. Figure 12A The coloring layer 2567R overlaps with the light-emitting element 2550R. Figure 12A The light from the light-emitting element 2550R shown in

[0336] is emitted toward the side where the transistor 2502t is provided. That is, the light (a part of it) from the light-emitting element 2550R passes through the coloring layer 2567R and is extracted in the direction indicated by the arrow in Figure 12A . In addition, a light-shielding layer 2567BM is provided at the end of the coloring layer 2567R.

[0337] The touch sensor 2595 is provided on the side of the transistor 2502t of the display panel 2501 (the side far from the light-emitting element 2550R) (refer to Figure 12A ).

[0338] Similar to the touch screen 2000, various structures of transistors can be used for the display panel 2501 of the touch screen 2000'. Although a bottom-gate transistor is used in Figure 12A , asFigure 12B As shown, a top-gate transistor can also be used.

[0339] Refer to Figure 13A and Figure 13B to illustrate an example of a method for driving a touch screen.

[0340] Figure 13A is a block diagram showing the structure of a mutual capacitance type touch sensor. Figure 13A It shows a pulse voltage output circuit 2601 and a current detection circuit 2602. Additionally, in Figure 13A , six wirings X1 to X6 represent the electrodes 2621 to which a pulse voltage is applied, and six wirings Y1 to Y6 represent the electrodes 2622 for detecting changes in current. Figure 13A It also shows each capacitor 2603 formed in the region where the electrode 2621 and the electrode 2622 overlap. Note that the functions of the electrode 2621 and the electrode 2622 can be interchanged with each other.

[0341] The pulse voltage output circuit 2601 is a circuit for sequentially applying a pulse voltage to the wirings X1 to X6. By applying a pulse voltage to the wirings X1 to X6, an electric field is generated between the electrode 2621 and the electrode 2622 of the capacitor 2603. When the electric field generated between these electrodes is shielded, for example, a change (mutual capacitance) occurs in the capacitor 2603. By utilizing this change, the approach or contact of a detection object can be detected.

[0342] The current detection circuit 2602 is a circuit for detecting changes in the current flowing through the wirings Y1 to Y6 due to changes in the mutual capacitance of the capacitor 2603. In the wirings Y1 to Y6, when there is no approach or contact of a detection object, the detected current value does not change. On the other hand, when the mutual capacitance decreases due to the approach or contact of a detection object, a decrease in the current value is detected. Additionally, an integration circuit or the like can be used for the detection of the current value.

[0343] Figure 13B is a timing diagram showing Figure 13A the input / output waveforms in the mutual capacitance type touch sensor shown in Figure 13B . In Figure 13B , the detection of detection objects in all rows and columns is performed during one frame period.

[0344] Pulse voltages are applied to wirings X1 to X6 in sequence, and the waveforms of wirings Y1 to Y6 change according to the pulse voltages. When there is no approach or contact of a detection object, the waveforms of wirings Y1 to Y6 change in the same way according to the voltage changes of wirings X1 to X6. In the part where there is an approach or contact of a detection object, the current value decreases, and the waveform of the voltage value also changes accordingly. Thus, by detecting the change in mutual capacitance, the approach or contact of the detection object can be detected.

[0345] Figure 13A Although a passive touch sensor that only has a capacitor 2603 provided at the crossing part of wirings is shown as the touch sensor, an active touch sensor including a transistor and a capacitor can also be used. Figure 14 An example of a sensor circuit included in the active touch sensor is shown.

[0346] Figure 14 The shown sensor circuit includes a capacitor 2603, a transistor 2611, a transistor 2612, and a transistor 2613.

[0347] A signal G2 is supplied to the gate of the transistor 2613. A voltage VRES is applied to one of the source and drain of the transistor 2613, and the other of the source and drain of the transistor 2613 is electrically connected to one electrode of the capacitor 2603 and the gate of the transistor 2611. One of the source and drain of the transistor 2611 is electrically connected to one of the source and drain of the transistor 2612, and a voltage VSS is applied to the other of the source and drain of the transistor 2611. A signal G1 is supplied to the gate of the transistor 2612, and the other of the source and drain of the transistor 2612 is electrically connected to the wiring ML. A voltage VSS is applied to the other electrode of the capacitor 2603.

[0348] Next, to Figure 14 The operation of the shown sensor circuit will be described. First, by supplying a potential that makes the transistor 2613 in the on state as the signal G2, a potential corresponding to the voltage VRES is supplied to the node n connected to the gate of the transistor 2611. Next, by supplying a potential that makes the transistor 2613 in the off state as the signal G2, the potential of the node n is held. Next, due to the approach or contact of a detection object such as a finger, the mutual capacitance of the capacitor 2603 changes, and the potential of the node n changes from VRES accordingly.

[0349] In the readout operation, a potential that makes the transistor 2612 in the on state is supplied as the signal G1. The current flowing through the transistor 2611, that is, the current flowing through the wiring ML, changes according to the potential of the node n. By detecting this current, the approach or contact of the detection object can be detected.

[0350] In each of the transistors 2611, 2612, and 2613, it is preferable to use an oxide semiconductor layer as the semiconductor layer in which a channel region is formed. In particular, it is preferable to use such a transistor as the transistor 2613 because the potential of the node n can be maintained for a long period of time and the frequency of the operation (refresh operation) of supplying VRES to the node n again can be reduced.

[0351] In addition, the structure shown in this embodiment can be used in appropriate combination with the structures shown in other embodiments.

[0352] (Embodiment 9)

[0353] In this embodiment, as a display device having a light-emitting element according to an embodiment of the present invention, with reference to Figure 15A , Figure 15B1 , Figure 15B2 , Figure 16 and Figure 17 a display device having a reflective liquid crystal element and a light-emitting element and capable of performing both transmissive mode and reflective mode displays will be described. Such a display device can be called an emissive OLED and reflective LC hybrid display (ER-hybrid display).

[0354] The display device shown in this embodiment can be driven with extremely low power consumption because it uses the reflective mode for display in bright places such as outdoors. On the other hand, in dark places such as at night or indoors, the transmissive mode can be used to display an image with the most appropriate brightness. Therefore, by combining these two modes, the display device can display an image with lower power consumption and higher contrast than existing display panels.

[0355] As an example of the display device of this embodiment, a display device is shown in which a liquid crystal element provided with a reflective electrode and a light-emitting element are stacked, and an opening of the reflective electrode is formed at a position overlapping the light-emitting element. In the reflective mode, visible light is reflected by the reflective electrode, and in the transmissive mode, light from the light-emitting element is emitted through the opening of the reflective electrode. In addition, transistors for driving these elements (liquid crystal element and light-emitting element) are preferably arranged on the same plane. Preferably, the liquid crystal element and the light-emitting element are stacked with an insulating layer therebetween.

[0356] Figure 15AThis is a block diagram showing the display device described in this embodiment. The display device 500 includes a circuit (G) 501, a circuit (S) 502, and a display unit 503. In the display unit 503, a plurality of pixels 504 are arranged in a matrix in the R direction and the C direction. The circuit (G) 501 is electrically connected to a plurality of wirings G1, a plurality of wirings G2, a plurality of wirings ANO, and a plurality of wirings CSCOM. These wirings are also electrically connected to a plurality of pixels 504 arranged in the R direction. The circuit (S) 502 is electrically connected to a plurality of wirings S1 and a plurality of wirings S2, and these wirings are electrically connected to a plurality of pixels 504 arranged in the C direction.

[0357] Each of the plurality of pixels 504 includes a liquid crystal element and a light-emitting element. The liquid crystal element and the light-emitting element have overlapping portions with each other.

[0358] Figure 15B1 The shape of the conductive film 505 used as the reflective electrode of the liquid crystal element included in the pixel 504 is shown. In addition, an opening 507 is formed at a position 506 overlapping with the light-emitting element, which is a part of the conductive film 505. That is, the light from the light-emitting element is emitted through the opening 507.

[0359] In Figure 15B1 The pixels 504 shown are arranged such that adjacent pixels 504 in the R direction have different colors. And the opening 507 is formed in such a way that it is not arranged in the R direction. Such an arrangement has the effect of suppressing crosstalk between the light-emitting elements of adjacent pixels 504.

[0360] The opening 507 can have, for example, a polygonal shape, a quadrilateral shape, an elliptical shape, a circular shape, a cross shape, etc., a thin strip shape, or a slit shape.

[0361] Figure 15B2 Another example of the arrangement of the conductive film 505 is shown.

[0362] The ratio of the opening 507 to the total area of the conductive film 505 (excluding the opening 507) affects the display of the display device. That is, the following problem occurs: the larger the area of the opening 507, the darker the display using the liquid crystal element, and on the other hand, the smaller the area of the opening 507, the darker the display using the light-emitting element. In addition, in addition to the above problem of the ratio of the opening, when the area of the opening 507 itself is small, there is also a problem of a decrease in the light extraction efficiency of the light emitted from the light-emitting element. From the viewpoint of maintaining the display quality when combining the liquid crystal element and the light-emitting element, the ratio of the above opening 507 to the total area of the conductive film 505 (excluding the opening 507) is preferably 5% or more and 60% or less.

[0363] Next, with reference to Figure 16 An example of the circuit structure of the pixel 504 will be described.Figure 16 Two adjacent pixels 504 are shown.

[0364] The pixel 504 includes a transistor SW1, a capacitor C1, a liquid crystal element 510, a transistor SW2, a transistor M, a capacitor C2, a light-emitting element 511, etc. In addition, these components are electrically connected to any one of wirings G1, G2, ANO, CSCOM, S1, and S2 in the pixel 504. The liquid crystal element 510 and the light-emitting element 511 are electrically connected to wirings VCOM1 and VCOM2, respectively.

[0365] The gate of the transistor SW1 is connected to the wiring G1. One of the source and drain of the transistor SW1 is connected to the wiring S1, and the other of the source and drain is connected to one electrode of the capacitor C1 and one electrode of the liquid crystal element 510. The other electrode of the capacitor C1 is connected to the wiring CSCOM. The other electrode of the liquid crystal element 510 is connected to the wiring VCOM1.

[0366] The gate of the transistor SW2 is connected to the wiring G2. One of the source and drain of the transistor SW2 is connected to the wiring S2, and the other of the source and drain is connected to one electrode of the capacitor C2 and the gate of the transistor M. The other electrode of the capacitor C2 is connected to one of the source and drain of the transistor M and the wiring ANO. The other of the source and drain of the transistor M is connected to one electrode of the light-emitting element 511. The other electrode of the light-emitting element 511 is connected to the wiring VCOM2.

[0367] In addition, the transistor M includes two gates sandwiching a semiconductor, and these two gates are electrically connected to each other. By adopting such a structure, the amount of current flowing through the transistor M can be increased.

[0368] The on / off state of the transistor SW1 is controlled by a signal from the wiring G1. A predetermined potential is supplied from the wiring VCOM1. In addition, the orientation of the liquid crystal of the liquid crystal element 510 can be controlled by a signal from the wiring S1. A predetermined potential is supplied from the wiring CSCOM.

[0369] The on / off state of the transistor SW2 is controlled by a signal from the wiring G2. The light-emitting element 511 can emit light by the potential difference applied from the wirings VCOM2 and ANO. In addition, the on state of the transistor M can be controlled by a signal from the wiring S2.

[0370] Therefore, in the structure shown in this embodiment, in the case of the reflection mode, the liquid crystal element 510 is controlled by the signals supplied from the wirings G1 and S1 and optical modulation is utilized, whereby display can be performed. In the case of the transmission mode, when signals are supplied from the wirings G2 and S2, the light-emitting element 511 can emit light. In the case of performing both modes simultaneously, desired driving can be performed according to the signals from the wirings G1, G2, S1, and S2.

[0371] Next, a cross-sectional schematic view of the display device 500 described in this embodiment is shown in Figure 17 and will be described in detail.

[0372] The display device 500 has a light-emitting element 523 and a liquid crystal element 524 between a substrate 521 and a substrate 522. In addition, the light-emitting element 523 and the liquid crystal element 524 are formed with an insulating layer 525 therebetween. That is, the light-emitting element 523 is located between the substrate 521 and the insulating layer 525, and the liquid crystal element 524 is located between the substrate 522 and the insulating layer 525.

[0373] A transistor 515, a transistor 516, a transistor 517, a coloring layer 528, etc. are provided between the insulating layer 525 and the light-emitting element 523.

[0374] An adhesive layer 529 is provided between the substrate 521 and the light-emitting element 523. The light-emitting element 523 has a conductive layer 530 used as one electrode, an EL layer 531, and a conductive layer 532 used as the other electrode, which are sequentially stacked on the insulating layer 525. In the light-emitting element 523 of the bottom emission type, the conductive layer 532 and the conductive layer 530 contain materials that reflect visible light and materials that transmit visible light, respectively. The light emitted by the light-emitting element 523 passes through the coloring layer 528, the insulating layer 525, and passes through the opening 533 and then through the liquid crystal element 524, and thus is emitted to the outside of the substrate 522.

[0375] Between the insulating layer 525 and the substrate 522, in addition to the liquid crystal element 524, there are also provided a color layer 534, a light-shielding layer 535, an insulating layer 546, a structure 536, etc. The liquid crystal element 524 has a conductive layer 537 used as one electrode, liquid crystal 538, a conductive layer 539 used as the other electrode, alignment films 540, 541, etc. In addition, the liquid crystal element 524 is a reflective liquid crystal element, and the conductive layer 539 is used as a reflective electrode, so the conductive layer 539 is formed of a material with a high reflectivity. In addition, since the conductive layer 537 is used as a transparent electrode, it is formed of a material that allows visible light to pass through. The alignment films 540, 541 are provided on the conductive layer 537 and the conductive layer 539 and are in contact with the liquid crystal 538. The insulating layer 546 is provided so as to cover the color layer 534 and the light-shielding layer 535 and is used as a protective layer. In addition, it is not necessarily required to provide the alignment films 540, 541.

[0376] An opening 533 is formed in a part of the conductive layer 539. A conductive layer 543 is provided in contact with the conductive layer 539. Since the conductive layer 543 has light transmissivity, a material that allows visible light to pass through is used for the conductive layer 543.

[0377] The structure 536 is used as a spacer to prevent the insulating layer 525 and the substrate 522 from approaching each other too closely. It is not necessarily required to provide the structure 536.

[0378] One of the source and drain of the transistor 515 is electrically connected to the conductive layer 530 of the light-emitting element 523. For example, the transistor 515 corresponds to Figure 16 the transistor M shown.

[0379] One of the source and drain of the transistor 516 is electrically connected to the conductive layer 539 and the conductive layer 543 of the liquid crystal element 524 through the terminal portion 518. In other words, the terminal portion 518 has the function of electrically connecting the conductive layers provided on the two surfaces of the insulating layer 525. The transistor 516 corresponds to Figure 16 the transistor SW1 shown.

[0380] In the region where the substrate 521 does not overlap with the substrate 522, a terminal portion 519 is provided. Similar to the terminal portion 518, the terminal portion 519 electrically connects the conductive layers provided on the two surfaces of the insulating layer 525. The terminal portion 519 is electrically connected to a conductive layer obtained by processing the same conductive film as the conductive layer 543. Thus, the terminal portion 519 can be electrically connected to the FPC 544 through the connection layer 545.

[0381] In a part of the region where the adhesive layer 542 is provided, a connection part 547 is provided. In the connection part 547, a conductive layer obtained by processing a conductive film the same as the conductive layer 543 and a part of the conductive layer 537 are electrically connected through a connection body 548. Therefore, a signal or potential input from the FPC 544 can be supplied to the conductive layer 537 through the connection body 548.

[0382] A structure body 536 is provided between the conductive layer 537 and the conductive layer 543. The structure body 536 has a function of maintaining the cell gap of the liquid crystal element 524.

[0383] As the conductive layer 543, oxides such as metal oxides, metal nitrides, or oxide semiconductors with reduced resistance are preferably used. In the case of using an oxide semiconductor, as the conductive layer 543, a material in which at least one of the concentrations of hydrogen, boron, phosphorus, nitrogen, and other impurities and the amount of oxygen defects is higher than that of the semiconductor used for the transistor can be used.

[0384] In addition, the structure shown in this embodiment can be used in appropriate combination with the structures shown in other embodiments.

[0385] (Embodiment 10)

[0386] In this embodiment, a light-emitting element according to an embodiment of the present invention will be described. The light-emitting element described in this embodiment has a structure different from that of the light-emitting element described in Embodiment 2. Refer to Figure 18A and Figure 18B to describe the element structure and manufacturing method of the light-emitting element. For parts that are the same as those in Embodiment 2, the description thereof will be omitted with reference to the description in Embodiment 2.

[0387] The light-emitting element described in this embodiment has a structure in which an EL layer 3202 including a light-emitting layer 3213 is sandwiched between a pair of electrodes (a cathode 3201 and an anode 3203) formed on a substrate 3200. The EL layer 3202 can be formed by laminating a light-emitting layer, a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, etc. in the same manner as the EL layer in Embodiment 2.

[0388] In this embodiment, as Figure 18A shown, a light-emitting element having the following structure will be described: on the cathode 3201 formed on the substrate 3200, an EL layer 3202 including an electron injection layer 3214, a light-emitting layer 3213, a hole transport layer 3215, and a hole injection layer 3216 is formed in sequence, and an anode 3203 is formed on the hole injection layer 3216. Here, although an electron transport layer is not provided, the electron injection layer 3214 can be used as an electron transport layer by using a material with high electron transport properties.

[0389] In the above-described light-emitting element, current flows due to the potential difference applied between the cathode 3201 and the anode 3203, and light is emitted due to the recombination of holes and electrons in the EL layer 3202. Then, the light is extracted to the outside through one or both of the cathode 3201 and the anode 3203. Therefore, one or both of the cathode 3201 and the anode 3203 are electrodes having translucency, and light can be extracted through the electrode having translucency.

[0390] As Figure 18A shown, in the light-emitting element shown in the present embodiment, the end portion of the cathode 3201 is covered with an insulator 3217. Note that, as Figure 18B shown, the insulator 3217 is formed so as to fill the space between adjacent cathodes 3201 (for example, 3201a and 3201b).

[0391] As the insulator 3217, an insulating organic compound or an inorganic compound can be used. As the organic compound, a photosensitive resin such as a resist material can be used, for example, an acrylic resin, a polyimide resin, a fluorine resin, etc. can be used. As the inorganic compound, for example, silicon oxide, silicon oxynitride, silicon nitride, etc. can be used. Note that the surface of the insulator 3217 preferably has water repellency. As a treatment method therefor, plasma treatment, chemical treatment (using an alkaline solution, an organic solvent), etc. can be employed.

[0392] In the present embodiment, the electron injection layer 3214 formed on the cathode 3201 is formed using a polymer compound. A polymer compound that is not easily soluble in a non-aqueous solvent and has high electron transportability is preferably used. Specifically, any of the materials (including alkali metals, alkaline earth metals, or their compounds in addition to polymer compounds) that can be used in Embodiment 2 of the electron injection layer 115 and the electron transport layer 114 are appropriately combined to form the electron injection layer 3214. The above materials are dissolved in a polar solvent, and the above layer is formed by a coating method.

[0393] Here, examples of the polar solvent include methanol, ethanol, propanol, isopropanol, butanol, ethylene glycol, glycerol, etc.

[0394] The light-emitting layer 3213 is formed on the electron injection layer 3214. The light-emitting layer 113 is formed (or coated) by forming (or coating) ink using a wet method (inkjet method or printing method). In the ink, the materials (light-emitting materials) that can be used in Embodiment 2 of the light-emitting layer 3213 are appropriately combined and dissolved (or dispersed) in a non-polar solvent. Although the electron injection layer 3214 is commonly used for light-emitting elements having different emission colors, materials corresponding to the emission colors are selected as the light-emitting layer 3213. As the non-polar solvent, an aromatic solvent such as toluene or xylene or a heteroaromatic solvent such as pyridine can be used. In addition, solvents such as hexane, 2-methylhexane, cyclohexane, and chloroform can also be used.

[0395] As shown Figure 18B in FIG. 1, ink for forming a light-emitting layer 3213 is applied from a head 3300 of an apparatus for applying a solution (hereinafter referred to as a solution application apparatus). Note that the head 3300 includes a plurality of ejection portions 3301a to 3301c having a function of ejecting the ink, and piezoelectric elements 3302a to 3302c are respectively provided in the ejection portions 3301a to 3301c. In addition, the ejection portions 3301a to 3301c are respectively filled with inks 3303a to 3303c containing light-emitting materials that exhibit different light-emitting colors.

[0396] The inks 3303a to 3303c are ejected from the ejection portions 3301a to 3301c, whereby light-emitting layers 3213a to 3213c that exhibit different light-emitting colors are respectively formed.

[0397] A hole transport layer 3215 is formed on the light-emitting layer 3213. The hole transport layer 3215 can be formed by appropriately combining any of the materials in Embodiment 2 applicable to the hole transport layer 112. The hole transport layer 3215 can be formed using a vacuum evaporation method or a coating method. In the case of using a coating method, a material dissolved in a solvent is applied to the light-emitting layer 3213 and the insulator 3217. As the coating method, an inkjet method, a spin coating method, a printing method, or the like can be used.

[0398] A hole injection layer 3216 is formed on the hole transport layer 3215. An anode 3203 is formed on the hole injection layer 3216. They can be formed by using a vacuum evaporation method by appropriately combining the materials shown in Embodiment 2.

[0399] Through the above steps, a light-emitting element can be formed. Note that when an organometallic complex of one embodiment of the present invention is used in the light-emitting layer, phosphorescent light emission based on the organometallic complex can be obtained. Therefore, a light-emitting element having higher efficiency than a light-emitting element formed using only a fluorescent compound can be realized.

[0400] In addition, the structure shown in this embodiment can be implemented in appropriate combination with the structures shown in other embodiments.

[0401] [Example 1]

[0402] [Synthesis Example 1]

[0403] In this example, an organometallic complex of one embodiment of the present invention, that is, bis{2-[6-(1,1-dimethylethyl)-4-pyrimidinyl-κN shown by the structural formula (100) in Embodiment 1 3Phenyl-κC}[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(tBuppm) 2 (ppy)]). Hereinafter, the synthesis method of [Ir(tBuppm) 2 (ppy)] is shown.

[0404] [Chemical formula 14]

[0405]

[0406] First, 4.2 g of di-μ-chloro-tetra{2-[6-(1,1-dimethylethyl)-4-pyrimidinyl-κN 3 phenyl-κC}diiridium(III) (abbreviation: [Ir(tBuppm) 2 Cl] 2 ) and 420 mL of dichloromethane were placed in a three-necked flask, and the atmosphere in the flask was replaced with nitrogen. A mixed solution of 2.5 g of silver trifluoromethanesulfonate and 200 mL of methanol was added dropwise to the flask, and then the mixture was stirred at room temperature overnight. The resulting mixture was filtered through a filter aid composed of diatomaceous earth, neutral silica gel, and diatomaceous earth in sequence, and the filtrate was concentrated to obtain a solid. Then, 2.0 g of 2-phenylpyridine (abbreviation: Hppy) and 80 mL of ethanol were added to the solid, and the mixture was refluxed for 14 hours under a nitrogen atmosphere.

[0407] The resulting mixture was filtered, and the residue was purified by flash column chromatography using dichloromethane and hexane as eluents in a 1:1 ratio. The resulting solution was concentrated, and then recrystallized using dichloromethane and methanol to obtain the organometallic complex [Ir(tBuppm) 2 (ppy)] as a yellow solid (yield: 13%).

[0408] Under a pressure of 2.3 Pa, 0.71 g of the obtained yellow solid was purified by gradient sublimation at an argon flow rate of 10 mL / min and at 260 °C. After sublimation purification, the target yellow solid was obtained in a yield of 86%. The following (a) shows the synthesis scheme of the above synthesis method.

[0409] [Chemical formula 15]

[0410]

[0411] Hereinafter, the analysis results of nuclear magnetic resonance ( 1 H-NMR) spectroscopy of the target product (yellow solid) obtained by the above synthesis method are shown. Figure 19 Shown 11H-NMR spectrum. These results indicate that the organometallic complex represented by Structural Formula (100), [Ir(tBuppm) 2 (ppy)], was obtained in this synthesis example.

[0412] 1 1H-NMR δ(CDCl 3 3): 1.36 (s, 9H), 1.38 (s, 9H), 6.78 (d, 1H), 6.83 - 6.96 (m, 9H), 7.59 - 7.64 (m, 2H), 7.68 (d, 1H), 7.76 - 7.79 (m, 4H), 7.89 (d, 1H), 8.14 (s, 1H), 8.24 (s, 1H).

[0413] Next, the ultraviolet-visible absorption spectrum (hereinafter simply referred to as "absorption spectrum") and emission spectrum of a dichloromethane solution of [Ir(tBuppm) 2 (ppy)] were measured. Using an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550), the absorption spectrum was measured at room temperature with a dichloromethane solution (0.092 mmol / L) placed in a quartz cell. In addition, using a fluorescence photometer (manufactured by Hamamatsu Photonics K.K., model FS920), the emission spectrum was measured at room temperature with a degassed dichloromethane solution (0.092 mmol / L) placed in a quartz cell.

[0414] Figure 20 The measurement results of the obtained absorption spectrum and emission spectrum are shown, where the horizontal axis represents the wavelength and the vertical axis represents the absorption intensity and luminescence intensity. In Figure 20 , two solid lines are shown. The thin line represents the absorption spectrum and the thick line represents the emission spectrum. Figure 20 The absorption spectrum in

[0415] was obtained by the following method: subtracting the absorbance measured by placing only dichloromethane in a quartz cell from the absorbance measured by placing a dichloromethane solution (0.092 mmol / L) in a quartz cell. Figure 20 As 2 shown, the organometallic complex [Ir(tBuppm)

[0416] has an emission peak at 554 nm and yellow luminescence is observed from the dichloromethane solution. 2 (ppy)] was subjected to mass spectrometry (MS) analysis using liquid chromatography-mass spectrometry (LC-MS).

[0417] In LC-MS analysis, liquid chromatography (LC) separation was performed using an ACQUITY UPLC (registered trademark) manufactured by Waters Corporation, and mass spectrometry (MS) analysis was performed using an Xevo G2 Tof MS manufactured by Waters Corporation. In the LC separation, ACQUITY UPLC BEH C8 (2.1×100 mm, 1.7 μm) was used as the column, and the column temperature was set at 40 °C. Acetonitrile was used for mobile phase A, and a 0.1% aqueous formic acid solution was used for mobile phase B. In addition, [Ir(tBuppm) 2 (ppy)] was dissolved in chloroform at an arbitrary concentration, and the mixture was diluted with acetonitrile to prepare a sample. The injection volume was 5.0 μL.

[0418] In MS analysis, ionization was carried out by electrospray ionization (ESI). At this time, the capillary voltage and the sample cone voltage were set at 3.0 kV and 50 V, respectively, and detection was performed in the positive ion mode. In the collision cell, the component with m / z = 770.28 ionized under the above conditions was collided with argon gas to dissociate into daughter ions. The energy at the time of collision with argon (collision energy) was set at 50 eV. The measured mass range was set at m / z = 100 to 1200. Figure 21 The results of detecting the dissociated daughter ions using a time-of-flight (TOF) type MS are shown.

[0419] Figure 21 It is shown that the daughter ions of [Ir(tBuppm) 2 (ppy)] are mainly detected around m / z = 615, 609, 558, 399, 213, and 156. Figure 21 The results in 2 (ppy)] show the characteristics of [Ir(tBuppm) 2 (ppy)], and thus can be regarded as important data for the identification of [Ir(tBuppm) 2 (ppy)] contained in the mixture.

[0420] The daughter ion near m / z = 615 can be estimated as a cation in a state where Hppy has detached from [Ir(tBuppm) 2 (ppy)]. The daughter ion near m / z = 558 can be estimated as a cation in a state where 4-(1,1-dimethylethyl)-6-phenylpyrimidine (abbreviation: HtBuppm) has detached from [Ir(tBuppm) 2 (ppy)]. The daughter ion near m / z = 399 can be estimated as a cation in a state where HtBuppm and Hppy have detached from [Ir(tBuppm) 2(ppy)]Cations in the detached state. The sub-ions around m / z = 213 can be estimated as cations in the state where a proton is added to HtBuppm. The sub-ions around m / z = 156 can be estimated as cations in the state where a proton is added to Hppy. These indicate that [Ir(tBuppm) 2 (ppy)]contains HtBuppm and Hppy.

[0421] [Example 2]

[0422] [Synthesis Example 2]

[0423] In this example, an organometallic complex of one embodiment of the present invention will be described, that is, bis{2-[6-(1,1-dimethylethyl)-4-pyrimidinyl-κN 3 phenyl-κC}[2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(tBuppm) 2 (mdppy)]) synthesis method. Hereinafter, the structure of [Ir(tBuppm) 2 (mdppy)] is shown.

[0424] [Chemical Formula 16]

[0425]

[0426] First, 4.9 g of [Ir(tBuppm) 2 Cl] 2 (abbreviation) and 450 mL of dichloromethane were placed in a three-necked flask, and the atmosphere in the flask was replaced with nitrogen. A mixed solution of 2.9 g of silver trifluoromethanesulfonate and 78 mL of methanol was added dropwise to this flask, and then stirred at room temperature overnight. The resulting mixture was filtered through diatomaceous earth, and the filtrate was concentrated to obtain a solid. Then, 2.3 g of 4-methyl-2,5-diphenylpyridine (abbreviation: Hmdppy) and 200 mL of ethanol were added to this solid, and the mixture was refluxed for 31 hours under a nitrogen atmosphere.

[0427] The resulting mixture was attached to a filter aid in which diatomaceous earth, silica, and diatomaceous earth were stacked in sequence, and then washed with hexane and ethanol. Then, dichloromethane was added, and the resulting solution was concentrated. Subsequently, purification was performed by flash column chromatography using ethyl acetate and hexane as developing solvents in a ratio of 1:5.

[0428] The resulting solution was concentrated, and then recrystallized using dichloromethane and methanol to obtain the organometallic complex [Ir(tBuppm) 2(mdppy)]1.1 g as an orange solid (yield: 28%).

[0429] At a pressure of 2.8 Pa, 0.75 g of the obtained orange solid was purified by gradient sublimation at an argon flow rate of 5 mL / min and at 240 °C. After sublimation purification, the target orange solid was obtained in a yield of 85%. The following (b) shows the synthetic scheme of the above synthetic method.

[0430] [Chemical formula 17]

[0431]

[0432] Hereinafter, the analysis results of the nuclear magnetic resonance ( 1 H-NMR) spectroscopy of the target substance (orange solid) obtained by the above synthetic method are shown. Figure 22 Shown 1 H-NMR spectrum. These results indicate that in this synthesis example, the organometallic complex [Ir(tBuppm) 2 (mdppy)] represented by the structural formula (102) was obtained.

[0433] 1 H-NMR δ(CD 2 Cl 2 ): 1.27 (s, 9H), 1.33 (s, 9H), 2.40 (s, 3H), 6.70 (d, 1H), 6.80 - 6.81 (m, 2H), 6.84 - 6.87 (m, 3H), 6.90 - 6.93 (m, 3H), 7.12 (d, 2H), 7.29 - 7.33 (m, 4H), 7.68 (d, 1H), 7.77 - 7.80 (m, 5H), 8.22 (d, 2H).

[0434] Next, the ultraviolet-visible absorption spectrum (hereinafter, simply referred to as "absorption spectrum") and emission spectrum of the deoxygenated dichloromethane solution of [Ir(tBuppm) 2 (mdppy)] were measured. Using an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550), and placing the dichloromethane solution (0.011 mmol / L) in a quartz cell, the absorption spectrum was measured at room temperature. In addition, using an absolute PL quantum yield measurement system (C11347-01 manufactured by Hamamatsu Photonics K.K.), in a glove box (LABstar M13 (1250 / 780) manufactured by Bright Corporation), the deoxygenated dichloromethane solution (0.011 mmol / L) was sealed in a quartz cell under a nitrogen atmosphere, and the emission spectrum was measured at room temperature.

[0435] Figure 23The measurement results of the obtained absorption spectrum and emission spectrum are shown, where the horizontal axis represents the wavelength and the vertical axis represents the absorption intensity and the luminescence intensity. In Figure 23 , two solid lines are shown. The thin line represents the absorption spectrum and the thick line represents the emission spectrum. Figure 23 The absorption spectrum in is the result obtained by the following method: subtracting the absorbance measured by putting only dichloromethane into a quartz cell from the absorbance measured by putting a dichloromethane solution (0.011 mmol / L) into a quartz cell.

[0436] As Figure 23 shown, the organometallic complex [Ir(tBuppm) 2 (mdppy)] has an emission peak at 555 nm and yellow luminescence is observed from the dichloromethane solution.

[0437] Next, mass spectrometry (MS) analysis was performed on [Ir(tBuppm) 2 (mdppy)] obtained in this example using liquid chromatography-mass spectrometry (LC-MS).

[0438] In the LC-MS analysis, liquid chromatography (LC) separation was performed using ACQUITY UPLC manufactured by Waters Corporation, and mass spectrometry (MS) analysis was performed using Xevo G2 Tof MS manufactured by Waters Corporation. In the LC separation, ACQUITY UPLC BEH C8 (2.1×100 mm, 1.7 μm) was used as the column, and the column temperature was set at 40 °C. Acetonitrile was used for mobile phase A and 0.1% formic acid aqueous solution was used for mobile phase B. In addition, [Ir(tBuppm) 2 (mdppy)] was dissolved in chloroform at an arbitrary concentration, and the mixture was diluted with acetonitrile to prepare a sample. The injection volume was 5.0 μL.

[0439] In the MS analysis, ionization was performed by electrospray ionization (ESI). At this time, the capillary voltage and the sample cone voltage were set at 3.0 kV and 30 V, respectively, and detection was performed in the positive ion mode. In the collision cell, the component with m / z = 860.33 ionized under the above conditions was collided with argon gas to dissociate into daughter ions. The energy at the time of collision with argon (collision energy) was set at 50 eV. The measured mass range was set at m / z = 100 to 1200. Figure 24 The results of detecting the dissociated daughter ions using time-of-flight (TOF) type MS are shown.

[0440] Figure 24 It is shown that [Ir(tBuppm) 2(mdppy)] daughter ions. Figure 24 The results in show that the source is [Ir(tBuppm) 2 (mdppy)] characteristics, so it can be regarded as important data for identifying [Ir(tBuppm) 2 (mdppy)] contained in the mixture.

[0441] The daughter ions near m / z = 648 can be estimated to be the cations of the state where HtBuppm dissociates from [Ir(tBuppm) 2 (mdppy)]. This indicates that [Ir(tBuppm) 2 (mdppy)] contains HtBuppm. The daughter ions near m / z = 615 can be estimated to be the cations of the state where Hmdppy dissociates from [Ir(tBuppm) 2 (mdppy)]. The daughter ions near m / z = 246 can be estimated to be the cations of Hmdppy. This indicates that [Ir(tBuppm) 2 (mdppy)] contains Hmdppy.

[0442] [Example 3]

[0443] [Synthesis Example 3]

[0444] In this example, an organometallic complex of an embodiment of the present invention is described, that is, [2-(4,5-dimethyl-2-pyridyl-κN)phenyl-κC]bis[2-(6-phenyl-4-pyrimidinyl-κN 3 )phenyl-κC]iridium(III) (abbreviation: [Ir(dppm) 2 (dmppy)]) synthesis method. Hereinafter, the structure of [Ir(dppm) 2 (dmppy)] is shown.

[0445] [Chemical Formula 18]

[0446]

[0447] [Step 1: Synthesis of 5-bromo-4-methyl-2-phenylpyridine]

[0448] 15 g (60 mmol) of 2,5-dibromo-4-methyl-2-phenylpyridine, 7.3 g (60 mmol) of phenylboronic acid, 3.0 g (22 mmol) of potassium carbonate, 380 mL of toluene, and 38 mL of water were placed in a 1000 mL three-necked flask. Then, the atmosphere in the flask was replaced with nitrogen, and while reducing the pressure in the flask, the mixture was stirred to degas. Thereafter, the atmosphere in the flask was replaced with nitrogen, and 3.5 g (3.0 mmol) of tetrakis(triphenylphosphine)palladium(0) was added to the mixture. The mixture was stirred at 110 °C for 16 hours under a nitrogen stream.

[0449] Water was added to the obtained reaction solution, and then extraction was performed using toluene. After washing the organic layer with saturated brine, anhydrous magnesium sulfate was added to the organic layer for drying. The mixture was filtered by gravity, and the filtrate was concentrated to obtain an oily substance. The obtained oily substance was purified by silica gel column chromatography. As the developing solvent, a mixed solvent of hexane and ethyl acetate at 12:1 was used. The fraction of the obtained substance was concentrated to obtain 13 g of a colorless oily substance. The obtained oily substance was a mixture of the target substance and the raw material 2,5-dibromo-4-methyl-2-phenylpyridine. Therefore, the reaction was repeated more than twice to obtain 6.2 g of a colorless oily substance of the target substance in a yield of 42%. The obtained colorless oily substance was identified as 5-bromo-4-methyl-2-phenylpyridine by nuclear magnetic resonance (NMR) method. The following (c-1) shows the synthesis scheme of Step 1.

[0450] [Chemical formula 19]

[0451]

[0452] <Step 2: Synthesis of 4,5-dimethyl-2-phenylpyridine (abbreviation: Hdmppy)>

[0453] Next, 6.2 g (25 mmol) of 5-bromo-4-methyl-2-phenylpyridine synthesized in Step 1, 5.2 g (41 mmol) of trimethoxycycloboroxane, 1.0 g (2.5 mmol) of 2-dicyclohexylphosphino-2’,6’-dimethoxybiphenyl (S-phos), 8.0 g (38 mmol) of tripotassium phosphate, 180 mL of toluene, and 18 mL of water were placed in a 500 mL three-necked flask. Then, the atmosphere in the flask was replaced with nitrogen, and while reducing the pressure in the flask, the mixture was stirred to degas. Thereafter, the atmosphere in the flask was replaced with nitrogen, and 0.46 g (0.5 mmol) of tris(dibenzylideneacetone)dipalladium(0) was added to the mixture. Under a nitrogen stream, the mixture was stirred at 110 °C for 23 hours. Water was added to the resulting reaction solution, and then extraction was performed using toluene. After washing the organic layer with saturated brine, anhydrous magnesium sulfate was added to the organic layer for drying. The mixture was filtered by gravity, and the filtrate was concentrated to obtain an oily substance.

[0454] The obtained oily substance was purified by silica gel column chromatography. As the developing solvent, a mixed solvent of hexane and ethyl acetate at 20:1 was used. The fraction of the obtained substance was concentrated to obtain 4.5 g of a yellow oily substance in a yield of 98%. The obtained yellow oily substance was identified as 4,5-dimethyl-2-phenylpyridine (abbreviation: Hdmppy) by nuclear magnetic resonance (NMR) spectroscopy. The following (c-2) shows the synthesis scheme of Step 2.

[0455] [Chemical formula 20]

[0456]

[0457] <Step 3: Synthesis of [2-(4,5-dimethyl-2-pyridinyl-κN 2 )phenyl-κC]bis[2-(6-phenyl-4-pyrimidinyl-κN 3 )phenyl-κC]iridium(III) (abbreviation: [Ir(dppm) 2 (dmppy)])>

[0458] Next, di-μ-chloro-tetra[2-(6-phenyl-4-pyrimidinyl-κN 3 )phenyl-κC]diiridium(III) (abbreviation: [Ir(dppm) 2 Cl] 2)2.1 g (1.5 mmol) and 300 mL of dichloromethane were placed in a 1000 mL three-necked flask and stirred under a nitrogen stream. A mixed solution of 1.2 g (4.5 mmol) of silver trifluoromethanesulfonate and 150 mL of methanol was added dropwise to this mixed solution, and the mixed solution was stirred in the dark for 16 hours. After the reaction at the specified time, the reaction mixture was filtered through diatomaceous earth.

[0459] The resulting filtrate was concentrated to obtain 2.8 g of a reddish-brown solid. Then, 2.8 g of the obtained solid, 30 mL of ethanol, 30 mL of methanol, and 1.1 g (6.0 mmol) of 4,5-dimethyl-2-phenylpyridine (abbreviation: Hdmppy) synthesized in Step 2 were placed in a 500 mL eggplant-shaped flask, and heated and refluxed under a nitrogen stream for 32 hours. After the reaction at the specified time, the reaction mixture was concentrated to obtain a solid. Dichloromethane was added to the obtained solid, and the mixture was filtered through a filter aid composed of diatomaceous earth, neutral silica gel, and diatomaceous earth stacked in sequence. The resulting filtrate was concentrated, and the obtained oily substance was purified by silica gel column chromatography. As the developing solvent, a mixed solvent of hexane and dichloromethane at a ratio of 2:1 was first used, and the ratio of dichloromethane was gradually increased. The fraction obtained when the ratio of dichloromethane was 100% was concentrated to obtain a solid. The obtained solid was recrystallized with ethyl acetate / hexane to obtain 0.35 g of a red solid with a yield of 14%. The following (c-3) shows the synthesis scheme of Step 3.

[0460] [Chemical formula 21]

[0461]

[0462] Hereinafter, the analysis results of nuclear magnetic resonance (NMR) spectroscopy of the red solid obtained in Step 3 are shown. Figure 25 Show 1 1H-NMR spectrum. These results indicate that the organometallic complex [Ir(dppm) 2 (dmppy)] represented by the structural formula (114) was obtained in this synthesis example.

[0463] 1 1H-NMR δ(CDCl 3):2.04 (s, 3H), 2.34 (s, 3H), 6.78 (d, 1H), 6.85 (t, 2H), 6.90 - 7.01 (m, 6H), 7.44 (s, 1H), 7.48 - 7.54 (m, 6H), 7.65 (d, 1H), 7.69 (s, 1H), 7.85 (d, 1H), 7.90 (d, 1H), 8.04 (d, 2H), 8.08 (d, 2H), 8.15 (s, 1H), 8.21 (s, 1H), 8.26 (s, 1H), 8.41 (s, 1H).

[0464] Next, the ultraviolet - visible absorption spectrum (hereinafter simply referred to as "absorption spectrum") and emission spectrum of a dichloromethane solution of [Ir(dppm) 2 (dmppy)] were measured. Using an ultraviolet - visible spectrophotometer (manufactured by JASCO Corporation, model V550), and placing the dichloromethane solution (0.0109 mmol / L) in a quartz cell, the absorption spectrum was measured at room temperature. In addition, using an absolute PL quantum yield measurement system (C11347 - 01 manufactured by Hamamatsu Photonics K.K.), in a glove box (LABstar M13(1250 / 780) manufactured by Bright Corporation), the deoxygenated dichloromethane solution (0.0109 mmol / L) was sealed in a quartz cell under a nitrogen atmosphere, and the emission spectrum was measured at room temperature.

[0465] Figure 26 The measurement results of the obtained absorption spectrum and emission spectrum are shown, where the horizontal axis represents the wavelength and the vertical axis represents the absorption intensity and luminescence intensity. In Figure 26 , two solid lines are shown, the thin line represents the absorption spectrum, and the thick line represents the emission spectrum. Figure 26 The absorption spectrum in

[0466] is the result obtained by the following method: subtracting the absorbance measured by placing only dichloromethane in the quartz cell from the absorbance measured by placing the dichloromethane solution (0.0109 mmol / L) in the quartz cell. Figure 26 As 2 shown, the organometallic complex [Ir(dppm)

[0467] Next, the obtained [Ir(dppm) 2 (dmppy)] in this example was analyzed by liquid chromatography - mass spectrometry (LC - MS) for mass spectrometry (MS).

[0468] In LC-MS analysis, liquid chromatography (LC) separation was performed using an ACQUITY UPLC manufactured by Waters Corporation, and mass spectrometry (MS) analysis was performed using an Xevo G2 Tof MS manufactured by Waters Corporation. In LC separation, ACQUITY UPLC BEH C8 (2.1×100 mm, 1.7 μm) was used as the column, and the column temperature was set at 40 °C. Acetonitrile was used for mobile phase A, and a 0.1% aqueous formic acid solution was used for mobile phase B. Additionally, [Ir(dppm) 2 (dmppy)] was dissolved in chloroform at an arbitrary concentration, and the mixture was diluted with acetonitrile to prepare the sample. The injection volume was 5.0 μL.

[0469] In MS analysis, ionization was performed by electrospray ionization (ESI). At this time, the capillary voltage and the sample cone voltage were set at 3.0 kV and 30 V, respectively, and detection was performed in the positive ion mode. In the collision cell, the component with m / z = 838.25 ionized under the above conditions was collided with argon gas to dissociate into daughter ions. The energy at the time of collision with argon (collision energy) was set at 50 eV. The measured mass range was set at m / z = 100 to 1200. Figure 27 The results of detecting the dissociated daughter ions using a time-of-flight (TOF) type MS are shown.

[0470] Figure 27 It is shown that the daughter ions of [Ir(dppm) 2 (dmppy)] were mainly detected around m / z = 653, 604, 423, 233, and 184. Figure 27 The results in 2 (dmppy)] show the characteristics derived from [Ir(dppm) 2 (dmppy)], and thus can be regarded as important data for the identification of [Ir(dppm)

[0471] The daughter ion around m / z = 653 can be estimated as a cation in the state where Hdmppy has detached from [Ir(dppm) 2 (dmppy)]. The daughter ion around m / z = 604 can be estimated as a cation in the state where 4,6-diphenylpyrimidine (abbreviation: Hdppm) has detached from [Ir(dppm) 2 (dmppy)]. The daughter ion around m / z = 423 can be estimated as a cation in the state where Hdppm and Hdmppy have detached from [Ir(dppm) 2(dmppy)] The cation in the detached state. The sub-ion around m / z = 233 can be estimated as the cation in the state where a proton is added to Hdppm. The sub-ion around m / z = 184 can be estimated as the cation in the state where a proton is added to Hdmppy. These indicate that [Ir(dppm) 2 (dmppy)] contains Hdppm and Hdmppy.

[0472] [Example 4]

[0473] [Synthesis Example 4]

[0474] In this example, an organometallic complex of one embodiment of the present invention will be described, that is, {2-[6-(1,1-dimethylethyl)-4-pyrimidinyl-κN 3 phenyl-κC}bis[2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(tBuppm)(mdppy) 2 ) synthesis method. Hereinafter, the structure of [Ir(tBuppm)(mdppy) 2 is shown.

[0475] [Chemical Formula 22]

[0476]

[0477] <Step 1: Di-μ-chloro-tetra[2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]diiridium(III) (abbreviation: [Ir(mdppy) 2 Cl] 2 ) synthesis>

[0478] First, 3.0 g of 4-methyl-2,5-diphenylpyridine (abbreviation: Hmdppy), 1.8 g of iridium(III) chloride hydrate, 30 mL of 2-ethoxyethanol, and 10 mL of water were placed in a round-bottom flask equipped with a reflux tube, and microwave irradiation (2.45 GHz, 100 W) was carried out for 2 hours while bubbling with argon. The resulting mixture was filtered, and then washed with methanol and hexane to obtain 2.9 g of the target product (yield: 65%, dark yellow solid). The following (d-1) shows the synthesis scheme of Step 1.

[0479] [Chemical Formula 23]

[0480]

[0481] <Step 2: {2-[6-(1,1-dimethylethyl)-4-pyrimidinyl-κN 3Phenyl-κC}bis[2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(tBuppm)(mdppy) 2 ) Synthesis

[0482] Next, 2.9 g of [Ir(mdppy) 2 Cl] 2 and 430 mL of dichloromethane were placed in a three-necked flask, and the atmosphere in the flask was replaced with nitrogen. A mixed solution of 1.0 g of silver trifluoromethanesulfonate and 53 mL of 2-propanol was added dropwise to this flask, and then stirred at room temperature for 18 hours. The resulting mixture was filtered through diatomaceous earth, and the filtrate was concentrated to obtain a solid. Then, 2.3 g of HtBuppm (abbreviation) and 40 mL of ethanol were added to this solid, and the mixture was refluxed for 18 hours under a nitrogen atmosphere. The resulting mixture was filtered, and the residue was purified by silica gel column chromatography using ethyl acetate and hexane as developing solvents in a ratio of 1:5. During the purification, the proportion of hexane was gradually decreased, and finally the ratio of ethyl acetate to hexane was 1:2. Purification was also carried out by flash column chromatography using dichloromethane and hexane as developing solvents in a ratio of 1:2. The resulting solution was concentrated, and then recrystallized using dichloromethane and hexane to obtain the organometallic complex [Ir(tBuppm)(mdppy) 2 as an orange solid (yield: 29%).

[0483] Under a pressure of 2.7 Pa, 0.90 g of the obtained orange solid was purified by gradient sublimation at an argon flow rate of 5 mL / min and at 260 °C. After sublimation purification, the desired orange solid was obtained in a yield of 88%. The following (d-2) shows the synthesis scheme of Step 2.

[0484] [Chemical formula 24]

[0485]

[0486] The following shows the analysis results of nuclear magnetic resonance ( 1 H-NMR) spectroscopy of the desired product (orange solid) obtained in Step 2. Figure 28 Show 1 H-NMR spectrum. These results indicate that the organometallic complex [Ir(tBuppm)(mdppy) 2 represented by the structural formula (120) was obtained in this synthesis example.

[0487] 1 H-NMR δ (CDCl 3):1.30(s, 9H), 2.32(s, 3H), 2.37(s, 3H), 6.83 - 6.97(m, 9H), 6.99 - 7.01(m, 2H), 7.13(d, 2H), 7.28 - 7.36(m, 7H), 7.45(s, 1H), 7.64 - 7.68(m, 2H), 7.70(s, 1H), 7.74(d, 3H), 8.21(s, 1H).

[0488] Next, the ultraviolet - visible absorption spectrum (hereinafter simply referred to as "absorption spectrum") and emission spectrum of the deoxygenated dichloromethane solution of [Ir(tBuppm)(mdppy) 2 were measured. Using an ultraviolet - visible spectrophotometer (manufactured by JASCO Corporation, model V550), and placing the dichloromethane solution (0.011 mmol / L) in a quartz cell, the absorption spectrum was measured at room temperature. In addition, using an absolute PL quantum yield measurement system (C11347 - 01 manufactured by Hamamatsu Photonics K.K.), in a glove box (LABstar M13(1250 / 780) manufactured by Bright Corporation), the deoxygenated dichloromethane solution (0.011 mmol / L) was sealed in a quartz cell under a nitrogen atmosphere, and the emission spectrum was measured at room temperature.

[0489] Figure 29 The measurement results of the obtained absorption spectrum and emission spectrum are shown, where the horizontal axis represents the wavelength and the vertical axis represents the absorption intensity and luminescence intensity. In Figure 29 , two solid lines are shown, the thin line represents the absorption spectrum, and the thick line represents the emission spectrum. Figure 29 The absorption spectrum in [] is the result obtained by the following method: subtracting the absorbance measured by placing only dichloromethane in the quartz cell from the absorbance measured by placing the dichloromethane solution (0.011 mmol / L) in the quartz cell.

[0490] As Figure 29 shown, the organometallic complex [Ir(tBuppm)(mdppy) 2 has an emission peak at 572 nm and orange luminescence is observed from the dichloromethane solution.

[0491] Next, liquid chromatography - mass spectrometry (LC - MS) was used to perform mass spectrometry (MS) analysis on [Ir(tBuppm)(mdppy) 2 obtained in this example.

[0492] In LC-MS analysis, liquid chromatography (LC) separation was performed using an ACQUITY UPLC (registered trademark) manufactured by Waters Corporation, and mass spectrometry (MS) analysis was performed using an Xevo G2 Tof MS manufactured by Waters Corporation. In the LC separation, ACQUITY UPLC BEH C8 (2.1×100 mm, 1.7 μm) was used as the column, and the column temperature was set at 40 °C. Acetonitrile was used for mobile phase A, and a 0.1% formic acid aqueous solution was used for mobile phase B. Additionally, [Ir(tBuppm)(mdppy) 2 was dissolved in chloroform, and the mixture was diluted with acetonitrile to prepare the sample. The injection volume was 5.0 μL.

[0493] In the MS analysis, ionization was performed by electrospray ionization (ESI). At this time, the capillary voltage and the sample cone voltage were set at 3.0 kV and 30 V, respectively, and detection was performed in the positive ion mode. In the collision cell, the component with m / z = 893.32 ionized under the above conditions was collided with argon gas to dissociate into daughter ions. The energy at the time of collision with argon (collision energy) was set at 70 eV. The measured mass range was set at m / z = 100 to 1200. Figure 30 The results of detecting the dissociated daughter ions using a time-of-flight (TOF) type MS are shown.

[0494] Figure 30 It is shown that the daughter ions of [Ir(tBuppm)(mdppy) 2 were mainly detected around m / z = 681, 648, 640, 632, 618, 510, 399, 387, and 246. Figure 30 The results in 2 show the characteristics derived from [Ir(tBuppm)(mdppy) 2 , and thus can be regarded as important data for identifying [Ir(tBuppm)(mdppy)

[0495] The daughter ion near m / z = 681 can be estimated as a cation in a state where HtBuppm (abbreviation) has detached from [Ir(tBuppm)(mdppy) 2 . This indicates that [Ir(tBuppm)(mdppy) 2 contains HtBuppm.

[0496] The daughter ion near m / z = 648 can be estimated as 4-methyl-2,5-diphenylpyridine (abbreviation: Hmdppy) detached from [Ir(tBuppm)(mdppy) 2Cation in a detached state. Daughter ions around m / z = 399 can be estimated to originate from two Hmdppy ligands detaching from [Ir(tBuppm)(mdppy) 2 in a detached state. This indicates that [Ir(tBuppm)(mdppy) 2 contains two Hmdppy ligands.

[0497] Daughter ions around m / z = 632 can be estimated to originate from a cation in a state where a methyl group detaches from a daughter ion around m / z = 648. Daughter ions around m / z = 618 can be estimated to originate from a cation in a state where a methyl group further detaches from a daughter ion around m / z = 632. Daughter ions around m / z = 387 can be estimated to originate from a cation in a state where a methyl group detaches from a daughter ion around m / z = 399. Daughter ions around m / z = 246 can be estimated to be the cation of Hmdppy in [Ir(tBuppm)(mdppy) 2 . This indicates that [Ir(tBuppm)(mdppy) 2 contains Hmdppy.

[0498] [Example 5]

[0499] In this example, an organic metal complex [Ir(tBuppm) 2 (mdppy)] (structural formula (102)) of one embodiment of the present invention, a light-emitting element 1 including [Ir(tBuppm)(mdppy) 2 (structural formula (120)), a comparative light-emitting element 3 including [Ir(tBuppm) 3 (structural formula (500)), and a comparative light-emitting element 4 including [Ir(mdppy) 3 (structural formula (600)) are manufactured. In addition, regarding the manufacture of these light-emitting elements, refer to Figure 31 for description. In addition, the chemical formulas of the materials used in this example are shown below.

[0500] [Chemical Formula 25]

[0501]

[0502] 《Manufacture of Light-Emitting Element》

[0503] First, indium tin oxide (ITO) containing silicon oxide is deposited on a glass substrate 900 by sputtering to form a first electrode 901 used as an anode. In addition, the thickness is set to 110 nm, and the electrode area is set to 2 mm × 2 mm.

[0504] Next, as a pretreatment for forming a light-emitting element on the substrate 900, the surface of the substrate is washed with water, baked at 200 °C for 1 hour, and then subjected to a UV ozone treatment for 370 seconds.

[0505] Then, the substrate is placed in a vacuum evaporation apparatus whose internal pressure is reduced to about 1×10 -4 Pa, and in the heating chamber of the vacuum evaporation apparatus, vacuum baking is performed at 170 °C for 30 minutes, and then the substrate 900 is cooled for about 30 minutes.

[0506] Next, the substrate 900 is fixed to a bracket provided in the vacuum evaporation apparatus with the surface on which the first electrode 901 is formed facing downward. In this embodiment, a case where a hole injection layer 911, a hole transport layer 912, a light-emitting layer 913, an electron transport layer 914, and an electron injection layer 915 included in the EL layer 902 are sequentially formed by a vacuum evaporation method will be described.

[0507] After reducing the pressure inside the vacuum apparatus to 1×10 -4 Pa, 1,3,5-tris(dibenzothiophen-4-yl)benzene (abbreviation: DBT3P-II) and molybdenum oxide are deposited by co-evaporation in such a manner that the mass ratio of DBT3P-II to molybdenum oxide is 4:2, thereby forming a hole injection layer 911 on the first electrode 901. The thickness of the hole injection layer 911 is set to 60 nm. Note that co-evaporation is an evaporation method in which a plurality of different substances are simultaneously evaporated from different evaporation sources.

[0508] Next, 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP) is deposited by evaporation to a thickness of 20 nm, thereby forming a hole transport layer 912.

[0509] Next, a light-emitting layer 913 is formed on the hole transport layer 912.

[0510] In the manufacture of the light-emitting element 1, 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenz[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluorene-2-amine (abbreviation: PCBBiF), [Ir(tBuppm) 2 (mdppy)] are deposited by co-evaporation in such a manner that the thickness is 20 nm and the mass ratio is 0.7:0.3:0.075, 2(mdppy)]. And, with a thickness of 20 nm and a mass ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir(tBuppm) 2 (mdppy)] of 0.8:0.2:0.075, deposit 2mDBTBPDBq-II, PCBBiF, and [Ir(tBuppm) 2 (mdppy)] by co-evaporation. Through the above steps, a light-emitting layer 913 of the light-emitting element 1 with a thickness of 40 nm is formed.

[0511] In the manufacture of the light-emitting element 2, with a thickness of 20 nm and a mass ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir(tBuppm)(mdppy) 2 of 0.7:0.3:0.075, deposit 2mDBTBPDBq-II, PCBBiF, and [Ir(tBuppm)(mdppy) 2 . And, with a thickness of 20 nm and a mass ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir(tBuppm) 2 (mdppy)] of 0.8:0.2:0.075, deposit 2mDBTBPDBq-II, PCBBiF, and [Ir(tBuppm) 2 (mdppy)] by co-evaporation. Through the above steps, a light-emitting layer 913 of the light-emitting element 2 with a thickness of 40 nm is formed.

[0512] In the manufacture of the comparative light-emitting element 3, with a thickness of 20 nm and a mass ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir(tBuppm) 3 of 0.7:0.3:0.075, deposit 2mDBTBPDBq-II, PCBBiF, and [Ir(tBuppm) 3 . And, with a thickness of 20 nm and a mass ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir(tBuppm) 3 of 0.8:0.2:0.075, deposit 2mDBTBPDBq-II, PCBBiF, and [Ir(tBuppm) 3 by co-evaporation. Through the above steps, a light-emitting layer 913 of the comparative light-emitting element 3 with a thickness of 40 nm is formed.

[0513] In the manufacture of the comparative light-emitting element 4, with a thickness of 20 nm and a mass ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir(mdppy) 3in a mass ratio of 0.7:0.3:0.075, 2mDBTBPDBq-II, PCBBiF, and [Ir(mdppy) were deposited by co-evaporation 3 . And, with a thickness of 20 nm and a mass ratio of 2mDBTBPDBq-II, PCBBiF, and [Ir(mdppy) 3 in a mass ratio of 0.8:0.2:0.075, 2mDBTBPDBq-II, PCBBiF, and [Ir(mdppy) were deposited by co-evaporation 3 . Through the above steps, the light-emitting layer 913 of the comparative light-emitting element 4 with a thickness of 40 nm was formed.

[0514] Next, 2mDBTBPDBq-II was deposited by evaporation on the light-emitting layer 913 of each light-emitting element with a thickness of 20 nm, and then Bphen was deposited by evaporation with a thickness of 10 nm, thereby forming the electron transport layer 914.

[0515] And, lithium fluoride was deposited by evaporation on the electron transport layer 914 with a thickness of 1 nm, thereby forming the electron injection layer 915.

[0516] Finally, aluminum was deposited by evaporation on the electron injection layer 915 with a thickness of 200 nm, thereby forming the second electrode 903 used as the cathode. Thus, each light-emitting element was obtained. In addition, throughout the above evaporation process, evaporation was performed using the resistance heating method.

[0517] Table 1 shows the element structures of the respective light-emitting elements manufactured by the above method.

[0518] [Table 1]

[0519]

[0520] *2mDBTBPDBq-II:PCBBiF:[Ir(tBuppm) 2 (mdppy)](0.7:0.3:0.075(20nm)\0.8:0.2:0.075(20nm)

[0521] **2mDBTBPDBq-II:PCBBiF:[Ir(tBuppm)(mdppy) 2 (0.7:0.3:0.075(20nm)\0.8:0.2:0.075

[0522] ***2mDBTBPDBq-II:PCBBiF:[Ir(tBuppm) 3(0.7:0.3:0.075(20nm)\0.8:0.2:0.075(20nm))

[0523] ****2mDBTBPDBq-II:PCBBiF:[Ir(mdppy) 3 (0.7:0.3:0.075(20nm)\0.8:0.2:0.075(20nm))

[0524] In addition, each of the manufactured light-emitting elements was sealed in a glove box containing a nitrogen atmosphere in such a manner as not to be exposed to the atmosphere (specifically, a sealant was applied around the element, and UV treatment was performed during sealing, and then, heat treatment was performed at 80°C for 1 hour).

[0525] 《Operating Characteristics of Each Light-Emitting Element》

[0526] The operating characteristics of each light-emitting element were measured. In addition, the measurement was performed at room temperature (an atmosphere in which the temperature was maintained at 25°C).

[0527] Figure 32 、 Figure 33 、 Figure and ​ show the current density-luminance characteristics, voltage-luminance characteristics, luminance-current efficiency characteristics, and voltage-current characteristics of Light-Emitting Element 1, Light-Emitting Element 2, Comparative Light-Emitting Element 3, and Comparative Light-Emitting Element 4, respectively.

[0528] Table 2 below shows the initial values of the main characteristics of each light-emitting element near 1000 cd / m 2 .

[0529] [Table 2]

[0530]

[0531] ​ shows the emission spectra of Light-Emitting Element 1, Light-Emitting Element 2, Comparative Light-Emitting Element 3, and Comparative Light-Emitting Element 4 when a current is applied at a current density of 2.5 mA / cm 2 . The emission spectrum of Light-Emitting Element 1 is derived from [Ir(tBuppm) 2 (mdppy)] and has a peak near 545 nm. The emission spectrum of Light-Emitting Element 2 is derived from [Ir(tBuppm)(mdppy) 2 and has a peak near 556 nm. The emission spectrum of Comparative Light-Emitting Element 3 is derived from [Ir(tBuppm) 3 and has a peak near 536 nm. The emission spectrum of Comparative Light-Emitting Element 4 is derived from [Ir(mdppy) 3, and has a peak near 530 nm.

[0532] Next, reliability tests of the above-described light-emitting elements were performed. ​ The results of the reliability test are shown. In ​ , the vertical axis represents the normalized luminance (%) when the initial luminance is 100%, and the horizontal axis represents the driving time (h) of the element. As the reliability test, a constant current drive test was performed at 2 mA.

[0533] ​ The results shown indicate that the light-emitting elements 1 and 2 each including the organometallic complex of one embodiment of the present invention have higher reliability than the comparative light-emitting elements 3 or 4. This may be because: the organometallic complex of one embodiment of the present invention has a shallow HOMO and a deep LUMO as a whole, and since the HOMO and LUMO are spatially separated because they are distributed on different ligands. In other words, in the organometallic complex used as the light-emitting material of the light-emitting elements 1 and 2, when transporting carriers and when in the excited state, holes are distributed on the ligand with high hole resistance (the first ligand where the HOMO is likely to be distributed), and electrons are distributed on the ligand with high electron resistance (the second ligand where the LUMO is likely to be distributed). Thereby, the stability when transporting carriers and when in the excited state can be increased, and a light-emitting element with a long service life can be manufactured. And, due to such separation of the HOMO and LUMO, the organometallic complex itself can transport both carriers, and thus, in the light-emitting element manufactured using the organometallic complex, the carrier balance can be adjusted, and the recombination region of the light-emitting layer can be prevented from narrowing. This can also be considered as a factor for realizing an increase in the service life.

[0534] Note that the compound (500) used in the comparative light-emitting element 3 includes three tBuppm ligands, and the compound (600) used in the comparative light-emitting element 4 includes three mdppy ligands. However, the light-emitting elements 1 and 2 each manufactured using the organometallic complex of one embodiment of the present invention including the tBuppm ligand having a pyrimidine ring and the mdppy ligand having a pyridine ring have a longer service life than the comparative light-emitting elements 3 or 4. This means that the two ligands in the organometallic complex of one embodiment of the present invention exhibit a new function of increasing the service life, rather than just a combination of their functions. This is a surprising phenomenon. As described below, it is considered that such an effect is obtained because the LUMO and the HOMO are respectively distributed on the tBuppm as a pyrimidine ligand and the mdppy as a pyridine ligand.

[0535] In the light-emitting element 2 manufactured using an organometallic complex having two mdppy ligands and one tBuppm ligand, the effect of increasing the service life is particularly remarkable. This indicates that, from the viewpoint of the increase in the service life, the presence of two ligands in the HOMO distribution and one ligand in the LUMO distribution is important. That is, when including a larger number of ligands capable of accepting holes, the organometallic complex is more stable, but when including only ligands capable of accepting holes, the organometallic complex has a shorter service life.

[0536] [Example 6]

[0537] In this example, a light-emitting element 5 including an organometallic complex [Ir(tBuppm) 2 (ppy)] (structural formula (100)) of one embodiment of the present invention was manufactured. In addition, regarding the manufacture of the light-emitting element 5, the same procedure as in Example 5 was referred to ​ for description. The chemical formulas of the materials used in this example are shown below.

[0538] [Chemical formula 26]

[0539]

[0540] 《Manufacture of Light-Emitting Element》

[0541] First, indium tin oxide (ITO) containing silicon oxide was deposited on a glass substrate 900 by sputtering to form a first electrode 901 used as an anode. In addition, the thickness was set to 70 nm, and the electrode area was set to 2 mm × 2 mm.

[0542] Next, as a pretreatment for forming a light-emitting element on the substrate 900, the surface of the substrate was washed with water, baked at 200 °C for 1 hour, and then subjected to a UV ozone treatment for 370 seconds.

[0543] Then, the substrate was placed in a vacuum evaporation apparatus whose internal pressure was reduced to about 1 × 10 -4 Pa, and in a heating chamber in the vacuum evaporation apparatus, vacuum baking was performed at 170 °C for 30 minutes, and then the substrate 900 was cooled for about 30 minutes.

[0544] Next, the substrate 900 was fixed to a bracket provided in the vacuum evaporation apparatus with the surface on which the first electrode 901 was formed facing downward. In this example, the case where a hole injection layer 911, a hole transport layer 912, a light-emitting layer 913, an electron transport layer 914, and an electron injection layer 915 included in an EL layer 902 were sequentially formed by vacuum evaporation was described.

[0545] After reducing the pressure in the vacuum apparatus to 1 × 10-4 After Pa, 1,3,5-tris(dibenzothiophen-4-yl)benzene (abbreviation: DBT3P-II) and molybdenum oxide were deposited by co-evaporation in such a way that the mass ratio of DBT3P-II to molybdenum oxide was 4:2, thereby forming a hole injection layer 911 on the first electrode 901. The thickness of the hole injection layer 911 was set to 60 nm. Note that co-evaporation refers to an evaporation method in which multiple different substances are simultaneously evaporated from different evaporation sources.

[0546] Next, 9-phenyl-9H-3-(9-phenyl-9H-carbazol-3-yl)carbazole (abbreviation: PCCP) was deposited by evaporation to a thickness of 20 nm, thereby forming a hole transport layer 912.

[0547] Next, a light-emitting layer 913 was formed on the hole transport layer 912.

[0548] In the manufacture of the light-emitting element 5, 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzof,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9H-fluorene-2-amine (abbreviation: PCBBiF), [Ir(tBuppm) 2 (ppy)] were deposited by co-evaporation in such a way that the mass ratio was 0.8:0.2:0.05. By the above steps, a light-emitting layer 913 with a thickness of 40 nm of the light-emitting element 5 was formed. 2 (ppy)] (structural formula (100)).

[0549] Next, 2mDBTBPDBq-II was deposited on the light-emitting layer 913 by evaporation to a thickness of 20 nm, and then BPhen was deposited by evaporation to a thickness of 10 nm, thereby forming an electron transport layer 914.

[0550] And, lithium fluoride was deposited on the electron transport layer 914 by evaporation to a thickness of 1 nm, thereby forming an electron injection layer 915.

[0551] Finally, aluminum was deposited on the electron injection layer 915 by evaporation to a thickness of 200 nm, thereby forming a second electrode 903 used as a cathode. Thus, a light-emitting element was obtained. In addition, throughout the above evaporation process, evaporation was performed using the resistance heating method.

[0552] Table 3 shows the element structure of the light-emitting element 5 manufactured by the above method.

[0553] [Table 3]

[0554]

[0555] *2mDBTBPDBq-II:PCBBiF:[Ir(tBuppm) 2 (ppy)](0.8:0.2:0.05(40nm))

[0556] The manufactured light-emitting element was sealed in a glove box containing a nitrogen atmosphere so as not to be exposed to the air (specifically, a sealant was applied around the element, UV treatment was performed during sealing, and then heat treatment was performed at 80° C. for 1 hour).

[0557] 《Operating characteristics of each light-emitting element》

[0558] The operating characteristics of the light emitting element 5 were measured. The measurement was performed at room temperature (atmosphere maintained at 25°C).

[0559] ​ , ​ , ​ and ​ The current density-luminance characteristics, voltage-luminance characteristics, luminance-current efficiency characteristics, and voltage-current characteristics of the light-emitting element 5 are shown respectively.

[0560] Table 4 below shows that 1000 cd / m 2 Initial values ​​of main characteristics of the light emitting element 5 nearby.

[0561] [Table 4]

[0562]

[0563] ​ Shown at 2.5 mA / cm 2 The emission spectrum of the light-emitting element 5 when a current of a current density of is applied. ​ As shown in FIG. 1 , the emission spectrum of the light-emitting element 5 has a peak near 545 nm, which indicates that the emission spectrum is derived from the organometallic complex [Ir(tBuppm) 2 (ppy)] green light.

[0564] [Example 7]

[0565] In this embodiment, the results of molecular orbital calculations of organometallic complexes according to one embodiment of the present invention represented by the following structural formulas (C1) to (C7) are described. Note that (C1) represents a compound obtained by substituting only the tert-butyl group of the organometallic complex used in the light-emitting element 5 with a methyl group. (C2) represents a compound obtained by substituting only the tert-butyl group of the organometallic complex used in the light-emitting element 1 with a methyl group. (C6) represents a compound obtained by substituting only the tert-butyl group of the organometallic complex used in the light-emitting element 2 with a methyl group. To reduce the computational load, the tert-butyl group of each compound is substituted with a methyl group. However, the alkyl length hardly affects the HOMO-LUMO distribution. Therefore, these calculation results can be considered to reflect the HOMO-LUMO distribution of the compounds used in the examples.

[0566] [Chemical formula 27]

[0567]

[0568] Note that Gaussian 09 is used in the molecular orbital calculations. 6-311G is used as the basis function, and B3PW91\6-311G is used to optimize the structure of the singlet ground state (S 0 ) of each molecule.

[0569] Table 5 shows the calculated electron density distributions of the HOMO and LUMO of each organometallic complex.

[0570] [Table 5]

[0571]

[0572]

[0573] As shown in the results of Table 5, for the organometallic complex represented by the structural formula (C1), the HOMO is mainly distributed on the phenylpyridine ligand and the iridium ion, and the LUMO is mainly distributed on the ligand of the phenylpyrimidine derivative. For the organometallic complex represented by the structural formula (C2), the HOMO is mainly distributed on the ligand of the phenylpyridine derivative and the iridium ion, and the LUMO is mainly distributed on the ligand of the phenylpyrimidine derivative. For the organometallic complex represented by the structural formula (C3), the HOMO is mainly distributed on the phenylpyridine ligand and the iridium ion, and the LUMO is mainly distributed on the ligand of the phenylpyrimidine derivative. For the organometallic complexes represented by the structural formulas (C4) and (C5), each HOMO is mainly distributed on the phenylpyridine ligand and the iridium ion, and the LUMO is mainly distributed on the ligand of the phenyltriazine derivative.

[0574] The HOMO of the iridium complex represented by structural formula (C6) is mainly distributed on the ligand of the phenylpyridine derivative and the iridium ion, and the LUMO is mainly distributed on the ligand of the phenylpyrimidine derivative. The HOMO of the iridium complex represented by structural formula (C7) is mainly distributed on the phenylpyridine ligand and the iridium ion, and the LUMO is mainly distributed on the ligand of the phenylpyrimidine derivative.

[0575] As described above, the following organometallic complex can be used as the organometallic complex of an embodiment of the present invention, that is, an organometallic complex in which when structural optimization is performed by molecular orbital calculation using B3PW91 as a general function and 6-311G as a basis function, its HOMO and LUMO are mainly distributed on different ligands. As shown in the above examples, by appropriately combining a ligand with a shallow HOMO and a ligand with a deep LUMO, the above structure can be obtained. The organometallic complex of an embodiment of the present invention obtained has high resistance to electrons and holes and high resistance to excited states, so when used as a light-emitting material of a device, the service life of the device can be increased. In addition, since it has excellent carrier injection properties and carrier transport properties with respect to electrons and holes, a light-emitting device with a low driving voltage and high luminous efficiency can be obtained. In addition, since the carrier injection properties and carrier transport properties are excellent, the carrier balance can be adjusted, which contributes to an increase in the service life.

[0576] [Example 8]

[0577] [Synthesis Example 5]

[0578] In this example, an organometallic complex of an embodiment of the present invention will be described, that is, bis{2-[6-(1,1-dimethylethyl)-4-pyrimidinyl-κN 3 phenyl-κC}[2-(4-phenyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(tBuppm) 2 (4dppy)]) represented by structural formula (117) in Embodiment 1. 2 (4dppy)] synthesis method. Hereinafter, the structure of [Ir(tBuppm)

[0579] [Chemical formula 28]

[0580]

[0581] First, [Ir(tBuppm) 2 Cl] 2(Abbreviation) 3.6 g and 250 mL of dichloromethane were placed in a three-necked flask, and the atmosphere in the flask was replaced with nitrogen. A mixed solution of 2.1 g of silver trifluoromethanesulfonate and 30 mL of methanol was added dropwise to the flask, and then the mixture was stirred at room temperature for 20 hours.

[0582] The resulting mixture was filtered through diatomaceous earth. The resulting filtrate was concentrated to obtain a solid. Then, 3.1 g of 2,4-diphenylpyridine (abbreviation: H4dppy) and 100 mL of ethanol were added to the solid, and the mixture was heated and refluxed under a nitrogen atmosphere for 23 hours.

[0583] The resulting reaction product was concentrated to obtain a solid. The resulting solid was purified by neutral silica gel column chromatography using chloroform and hexane as eluents in a ratio of 2:3. The fractions of the resulting substance were concentrated, and then recrystallized using dichloromethane and methanol to obtain 1.7 g of the organometallic complex [Ir(tBuppm) 2 (4dppy)] as an orange solid (yield: 36%).

[0584] At a pressure of 3.0 Pa, 1.7 g of the resulting orange solid was purified by gradient sublimation at an argon flow rate of 5 mL / min and at 285 °C. After sublimation purification, the desired orange solid was obtained in a yield of 94%. The following (e) shows the synthetic scheme of the above synthetic method.

[0585] [Chemical formula 29]

[0586]

[0587] Hereinafter, the analysis results of nuclear magnetic resonance ( 1 H-NMR) spectroscopy of the orange solid obtained by the above synthetic method are shown. ​ Shown 1 H-NMR spectrum. These results indicate that the organometallic complex [Ir(tBuppm) 2 (4dppy)] represented by the structural formula (117) was obtained in this synthesis example.

[0588] 1 H-NMR δ(CD 2 Cl 2 ): 1.36 (s, 9H), 1.39 (s, 9H), 6.82 (d, 1H), 6.85 - 6.88 (1H), 6.89 - 6.98 (m, 7H), 7.13 (dd, 1H), 7.44 - 7.52 (m, 3H), 7.62 (d, 2H), 7.66 (d, 1H), 7.76 - 7.81 (m, 5H), 8.06 (s, 1H), 8.24 (s, 1H), 8.27 (s, 1H).

[0589] Next, measure the ultraviolet-visible absorption spectrum (hereinafter simply referred to as the "absorption spectrum") and emission spectrum of the deoxygenated dichloromethane solution of [Ir(tBuppm) 2 (4dppy)]. Using an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550), place the dichloromethane solution (0.013 mmol / L) in a quartz cell and measure the absorption spectrum at room temperature. In addition, using an absolute PL quantum yield measurement system (C11347-01 manufactured by Hamamatsu Photonics K.K.), seal the deoxygenated dichloromethane solution (0.013 mmol / L) in a quartz cell under a nitrogen atmosphere in a glove box (LABstar M13 (1250 / 780) manufactured by Bright Corporation) and measure the emission spectrum at room temperature.

[0590] ​ The measurement results of the obtained absorption spectrum and emission spectrum are shown, where the horizontal axis represents the wavelength and the vertical axis represents the absorption intensity and luminescence intensity. In Figure 44 , two solid lines are shown, the thin line represents the absorption spectrum, and the thick line represents the emission spectrum. Figure 44 The absorption spectrum in [] is the result obtained by the following method: subtracting the absorbance measured by placing only dichloromethane in the quartz cell from the absorbance measured by placing the dichloromethane solution (0.013 mmol / L) in the quartz cell.

[0591] As Figure 44 shown, the organometallic complex [Ir(tBuppm) 2 (4dppy)] has an emission peak at 552 nm, and yellow luminescence is observed from the dichloromethane solution.

[0592] Next, perform mass spectrometry (MS) analysis on [Ir(tBuppm) 2 (4dppy)] obtained in this example using liquid chromatography-mass spectrometry (LC-MS).

[0593] In LC-MS analysis, perform LC (liquid chromatography) separation using UltiMate3000 manufactured by Thermo Fisher Scientific and perform mass spectrometry (MS) using Q Exactive manufactured by Thermo Fisher Scientific.

[0594] In LC separation, use an arbitrary column, the column temperature is 40 °C, and its infusion conditions are as follows: appropriately select the solvent, dissolve [Ir(tBuppm) 2 (4dppy)] in an organic solvent at an arbitrary concentration for sample preparation, and the injection volume is 5.0 μL.

[0595] In MS analysis, targeted MS 2 (Targeted-MS 2 ) was used to measure the component with m / z = 845.31 of the ions derived from [Ir(tBuppm) 2 (4dppy)]. In targeted MS 2 , the mass range was set to ±2.0 m / z, and detection was performed in the positive mode. The energy used to accelerate the ions (normalized collision energy: NCE) was set to 30 for measurement. Figure 45 The obtained MS spectrum is shown.

[0596] Figure 45 It is shown that the fragment ions of [Ir(tBuppm) 2 (4dppy)] were mainly detected around m / z = 634 and 615. Figure 45 The results in 2 (4dppy)] show the characteristics of [Ir(tBuppm) 2 (4dppy)], and thus can be regarded as important data for identifying [Ir(tBuppm)

[0597] The fragment ion near m / z = 634 can be estimated to be a cation in the state where HtBuppm (abbreviation) detaches from [Ir(tBuppm) 2 (4dppy)]. This indicates that [Ir(tBuppm) 2 (4dppy)] contains tBuppm (abbreviation). The fragment ion near m / z = 615 can be estimated to be a cation in the state where H4dppy (abbreviation) detaches from [Ir(tBuppm) 2 (4dppy)]. This indicates that [Ir(tBuppm) 2 (4dppy)] contains H4dppy (abbreviation).

[0598] [Example 9]

[0599] 《Synthesis Example 6》

[0600] In this example, the synthesis method of an organometallic complex of an embodiment of the present invention, that is, bis{2-[4-phenyl-2-(1,3,5-triazine)-κN]phenyl-κC}[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(dptzn) 2 (ppy)]) represented by the structural formula (200) in Embodiment 1, is described. Hereinafter, the structure of [Ir(dptzn) 2 (ppy)] is shown.

[0601] [Chemical Formula 30]

[0602]

[0603] <Bis{2-[4-phenyl-2-(1,3,5-triazinato-κN)phenyl-κC]}[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(dptzn) 2 (ppy)]) synthesis>

[0604] First, 2.5 g (2.3 mmol) of di-μ-chloro-tetrakis[2-(2-pyridyl-κN)phenyl-κC]diiridium(III) (abbreviation: [Ir(ppy) 2 Cl] 2 ) and 400 mL of dichloromethane were placed in a 1000 mL three-necked flask and stirred under a nitrogen stream.

[0605] A mixed solution of 1.8 g (6.9 mmol) of silver trifluoromethanesulfonate and 120 mL of methanol was added dropwise to the mixed solution, and the mixed solution was stirred in the dark for 17 hours. After the reaction at the specified time, the reaction mixture was filtered through diatomaceous earth. The resulting filtrate was concentrated to obtain 3.7 g of a yellow solid. Then, 3.7 g of the obtained solid, 100 mL of 1-butanol, and 2.1 g (9.2 mmol) of 2,6-diphenyl-1,3,5-triazine (abbreviation: Hdptzn) were placed in a 300 mL eggplant-shaped flask and heated and refluxed under a nitrogen stream for 35 hours.

[0606] After the reaction at the specified time, the reaction mixture was concentrated to obtain a solid. Dichloromethane was added to the obtained solid, and the mixture was filtered through a filter aid composed of diatomaceous earth, neutral silica gel, and diatomaceous earth stacked in sequence. The resulting filtrate was concentrated to obtain a solid. The obtained solid was purified by silica gel column chromatography. As the developing solvent, a mixed solvent of hexane and dichloromethane at 2:1 was first used, and then a mixed solvent of hexane and dichloromethane at 3:4 was used. The fractions of the obtained substance were concentrated to obtain a solid. The obtained solid was recrystallized with ethyl acetate / ethanol to obtain 0.19 g of an orange solid in a 5% yield. The following (f) shows the synthesis scheme.

[0607] [Chemical formula 31]

[0608]

[0609] The following shows the analysis results of nuclear magnetic resonance ( 1 H-NMR) spectroscopy of the orange solid obtained by the above synthesis method. Figure 46 Shown 11H-NMR spectrum. These results indicate that the organometallic complex [Ir(dptzn) 2 (ppy)] was obtained in this synthesis example.

[0610] 1 1H-NMR δ(CDCl 3 3): 6.81 - 7.04 (m, 10H), 7.51 - 7.60 (m, 6H), 7.70 - 7.71 (m, 2H), 7.85 (d, 1H), 7.95 (d, 1H), 8.21 (s, 1H), 8.37 (t, 2H), 8.50 (s, 1H), 8.55 (d, 2H), 8.58 (d, 2H).

[0611] Next, the ultraviolet-visible absorption spectrum (hereinafter simply referred to as the "absorption spectrum") and the emission spectrum of a dichloromethane solution of [Ir(dptzn) 2 (ppy)] were measured. Using an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550), and placing the dichloromethane solution (0.0123 mmol / L) in a quartz cell, the absorption spectrum was measured at room temperature. In addition, using an absolute PL quantum yield measurement system (C11347-01 manufactured by Hamamatsu Photonics K.K.), in a glove box (LABstar M13(1250 / 780) manufactured by Bright Corporation), the deoxygenated dichloromethane solution (0.0123 mmol / L) was sealed in a quartz cell under a nitrogen atmosphere, and the emission spectrum was measured at room temperature. Figure 47 The measurement results of the obtained absorption spectrum and emission spectrum are shown, where the horizontal axis represents the wavelength and the vertical axis represents the absorption intensity and the luminescence intensity. Note that Figure 47 the absorption spectrum in

[0612] is the result obtained by the following method: subtracting the absorbance measured by placing only dichloromethane in the quartz cell from the absorbance measured by placing the dichloromethane solution (0.0123 mmol / L) in the quartz cell. Figure 47 As 2 shown, the organometallic complex [Ir(dptzn)

[0613] (ppy)] has an emission peak at 631 nm and emits red light when observed from dichloromethane. 2 Next, [Ir(dptzn)

[0614] In LC-MS analysis, LC (liquid chromatography) separation was performed using an UltiMate 3000 manufactured by Thermo Fisher Scientific, and mass spectrometry (MS) was performed using a Q Exactive manufactured by Thermo Fisher Scientific.

[0615] In the LC separation, an arbitrary column was used, the column temperature was 40 °C, and the infusion conditions were as follows: a solvent was appropriately selected, and [Ir(dptzn) 2 (ppy)] was dissolved in an organic solvent at an arbitrary concentration for sample preparation, and the injection volume was 5.0 μL.

[0616] In the MS analysis, targeted MS 2 (Targeted-MS 2 ) method was used to measure the component with m / z = 812.21 of the ions derived from [Ir(dptzn) 2 (ppy)]. In the targeted MS 2 , the mass range was set to ±2.0 m / z, and detection was performed in the positive mode. The energy for accelerating the target ion (normalized collision energy: NCE) was set to 30 for measurement. Figure 48 The obtained MS spectrum is shown.

[0617] Figure 48 It is shown that the fragment ions of [Ir(dptzn) 2 (ppy)] were mainly detected around m / z = 656 and 579. Figure 48 The results in 2 show the characteristics of [Ir(dptzn) 2 (ppy)], and thus can be regarded as important data for identifying [Ir(dptzn)

[0618] (ppy)] contained in the mixture. 2 The fragment ion near m / z = 656 can be estimated as a cation in the state where phenylpyridine (abbreviation: Hppy) is detached from [Ir(dptzn) 2 (ppy)]. The fragment ion near m / z = 579 can be estimated as a cation in the state where Hdptzn (abbreviation) is detached from [Ir(dptzn) 2 (ppy)]. These indicate that [Ir(dptzn)

[0619] [Example 10]

[0620] <<Synthesis Example 7>>

[0621] In this embodiment, an organometallic complex of an embodiment of the present invention is described, that is, {2-[4-phenyl-2-(1,3,5-triazine)-κN]phenyl-κC}bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) 2 (dptzn)]) as represented by structural formula (300) in Embodiment 1. The synthesis method of [Ir(ppy) 2 (dptzn)] is as follows. The structure of [Ir(ppy)

[0622] [Chemical formula 32]

[0623]

[0624] <{2-[4-phenyl-2-(1,3,5-triazine)-κN]phenyl-κC}bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) 2 (dptzn)]) synthesis>

[0625] First, 2.5 g (2.3 mmol) of di-μ-chloro-tetrakis[2-(2-pyridyl-κN)phenyl-κC]diiridium(III) (abbreviation: [Ir(ppy) 2 Cl] 2 ) and 400 mL of dichloromethane were placed in a 1000 mL three-necked flask and stirred under a nitrogen stream. A mixed solution of 1.8 g (6.9 mmol) of silver trifluoromethanesulfonate and 120 mL of methanol was added dropwise to this mixed solution, and the mixed solution was stirred in the dark for 17 hours.

[0626] After the reaction for the specified time, the reaction mixture was filtered through diatomaceous earth. The resulting filtrate was concentrated to obtain 3.7 g of a yellow solid. The obtained 3.7 g of solid, 100 mL of 1-butanol, and 2.1 g (9.2 mmol) of 2,6-diphenyl-1,3,5-triazine (abbreviation: Hdptzn) were placed in a 300 mL eggplant-shaped flask and heated and refluxed under a nitrogen stream for 35 hours. After the reaction for the specified time, the reaction mixture was concentrated to obtain a solid.

[0627] Dichloromethane was added to the obtained solid, and the mixture was filtered through a filter aid with diatomaceous earth, neutral silica gel, and diatomaceous earth stacked in sequence. The resulting filtrate was concentrated to obtain a solid. The obtained solid was purified by silica gel column chromatography. As the developing solvent, a mixed solvent of hexane and dichloromethane at 2:1 was used first, and then a mixed solvent of hexane and dichloromethane at 3:4 was used. The fraction of the obtained substance was concentrated to obtain a solid. The obtained solid was recrystallized with ethyl acetate / ethanol to obtain 0.11 g of an orange solid with a yield of 3%. The synthesis scheme is shown in (g) below.

[0628] [Chemical Formula 33]

[0629]

[0630] The following shows the analysis results of the nuclear magnetic resonance ( 1 H-NMR) spectroscopy of the orange solid obtained by the above synthesis method. Figure 49 Shows 1 the H-NMR spectrum. These results indicate that in this synthesis example, an organometallic complex [Ir(ppy) 2 (dptzn)] represented by Structural Formula (300) was obtained.

[0631] 1 H-NMR δ(CDCl 3 ): 6.80 - 7.00 (m, 11H), 7.50 - 7.70 (m, 8H), 7.81 (d, 1H), 7.90 - 7.94 (m, 2H), 8.20 (s, 1H), 8.33 - 8.35 (m, 1H), 8.56 (d, 2H).

[0632] Next, the ultraviolet-visible absorption spectrum (hereinafter simply referred to as "absorption spectrum") and emission spectrum of the dichloromethane solution of [Ir(ppy) 2 (dptzn)] were measured. Using an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, Model V550) and placing the dichloromethane solution (0.0192 mmol / L) in a quartz cell, the absorption spectrum was measured at room temperature. In addition, using an absolute PL quantum yield measurement system (C11347-01 manufactured by Hamamatsu Photonics K.K.), in a glove box (LABstar M13(1250 / 780) manufactured by Bright Corporation), the dichloromethane-deoxygenated solution (0.0192 mmol / L) was sealed in a quartz cell under a nitrogen atmosphere, and the emission spectrum was measured at room temperature. Figure 50 Shows the measurement results of the obtained absorption spectrum and emission spectrum, where the horizontal axis represents the wavelength and the vertical axis represents the absorption intensity and luminescence intensity. Figure 50 The absorption spectrum in

[0633] is the result obtained by the following method: subtracting the absorbance measured by placing only dichloromethane in the quartz cell from the absorbance measured by placing the dichloromethane solution (0.0192 mmol / L) in the quartz cell. Figure 50 As shown, the organometallic complex [Ir(ppy) 2 (dptzn)] has an emission peak at 663 nm and red luminescence is observed from dichloromethane.

[0634] Next, [Ir(ppy) 2 (dptzn)] obtained in this example was analyzed by liquid chromatography - mass spectrometry (LC - MS).

[0635] In the LC - MS analysis, LC (liquid chromatography) separation was performed using an UltiMate 3000 manufactured by Thermo Fisher Scientific, and mass spectrometry (MS) was performed using a Q Exactive manufactured by Thermo Fisher Scientific.

[0636] In the LC separation, an arbitrary column was used, the column temperature was 40 °C, and the infusion conditions were as follows: The solvent was appropriately selected, and [Ir(ppy) 2 (dptzn)] was dissolved in an organic solvent at an arbitrary concentration for sample preparation, and the injection volume was 5.0 μL.

[0637] In the MS analysis, targeted MS 2 (Targeted - MS 2 ) method was used to measure the component with m / z = 734.19 of the ions derived from [Ir(ppy) 2 (dptzn)]. In the targeted MS 2 , the mass range was set to ±2.0 m / z, and detection was performed in the positive mode. The energy for accelerating the target ion (normalized collision energy: NCE) was set to 30 for measurement. Figure 51 The obtained MS spectrum is shown.

[0638] Figure 51 It is shown that the fragment ions of [Ir(ppy) 2 (dptzn)] were mainly detected around m / z = 579 and 501. Figure 51 The results in 2 (dptzn)] show the characteristics of [Ir(ppy) 2 (dptzn)], so it can be regarded as important data for identifying [Ir(ppy)

[0639] The fragment ion near m / z = 579 can be estimated as a cation in the state where phenylpyridine (abbreviation: Hppy) detaches from [Ir(ppy) 2 (dptzn). The fragment ion near m / z = 501 can be estimated as a cation in the state where Hdptzn (abbreviation) detaches from [Ir(ppy) 2 (dptzn). These indicate that [Ir(ppy) 2 (dptzn) contains Hppy (abbreviation) and Hdptzn (abbreviation).

[0640] [Example 11]

[0641] Synthesis Example 8

[0642] In this example, an organometallic complex of one embodiment of the present invention will be described, that is, bis[2-(4,5-dimethyl-2-pyridyl-κN)phenyl-κC][2-(6-phenyl-4-pyrimidinyl-κN 3 )phenyl-κC]iridium(III) (abbreviation: [Ir(dppm)(dmppy) 2 ) will be described. Hereinafter, the structure of [Ir(dppm)(dmppy) 2 will be shown.

[0643] [Chemical formula 34]

[0644]

[0645] <Step 1: Synthesis of 5-bromo-4-methyl-2-phenylpyridine>

[0646] First, 15 g (60 mmol) of 2,5-dibromo-4-methyl-2-phenylpyridine, 7.3 g (60 mmol) of phenylboronic acid, 3.0 g (22 mmol) of potassium carbonate, 380 mL of toluene, and 38 mL of water were placed in a 1000 mL three-necked flask. Then, the atmosphere in the flask was replaced with nitrogen, and while reducing the pressure in the flask, the mixture was stirred to degas. Thereafter, the atmosphere in the flask was replaced with nitrogen, and 3.5 g (3.0 mmol) of tetrakis(triphenylphosphine)palladium(0) was added to the mixture. The mixture was stirred at 110 °C for 16 hours under a nitrogen stream.

[0647] Water was added to the obtained reaction solution to separate the solution into an organic layer and an aqueous layer, and the aqueous layer was extracted with toluene. The organic layer and the obtained extraction solution were combined and washed with saturated brine. Then, anhydrous magnesium sulfate was added to the solution for drying. The mixture was filtered by gravity, and the filtrate was concentrated to obtain an oil. The obtained oil was purified by silica gel column chromatography. As the developing solvent, a mixed solvent of hexane and ethyl acetate at 12:1 was used. The fraction of the obtained substance was concentrated to obtain 13 g of a colorless oil. The obtained oil was a mixture of the target product and the raw material 2,5-dibromo-4-methyl-2-phenylpyridine. Therefore, the reaction was repeated two or more times to obtain 6.2 g of a colorless oil of the target product with a yield of 42%. The obtained colorless oil was identified as 5-bromo-4-methyl-2-phenylpyridine by nuclear magnetic resonance (NMR) spectroscopy. The following (h-1) shows the synthesis scheme of Step 1.

[0648] [Chemical formula 35]

[0649]

[0650] <Step 2: Synthesis of 4,5-dimethyl-2-phenylpyridine (abbreviation: Hdmppy)>

[0651] Next, 6.2 g (25 mmol) of 5-bromo-4-methyl-2-phenylpyridine synthesized in Step 1, 5.2 g (41 mmol) of trimethoxycycloboroxane, 1.0 g (2.5 mmol) of 2-dicyclohexylphosphino-2’,6’-dimethoxybiphenyl (S-phos), 8.0 g (38 mmol) of tripotassium phosphate, 180 mL of toluene, and 18 mL of water were placed in a 500 mL three-necked flask. Then, the atmosphere in the flask was replaced with nitrogen, and while reducing the pressure in the flask, the mixture was stirred to degas. Thereafter, the atmosphere in the flask was replaced with nitrogen, and 0.46 g (0.5 mmol) of tris(dibenzylideneacetone)dipalladium(0) was added to the mixture. Under a nitrogen stream, the mixture was stirred at 110 °C for 23 hours.

[0652] Water was added to the obtained reaction solution to separate the solution into an organic layer and an aqueous layer, and the aqueous layer was extracted with toluene. The organic layer and the obtained extraction solution were combined and washed with saturated brine. Then, anhydrous magnesium sulfate was added to the organic layer for drying. The obtained mixture was filtered by gravity, and the filtrate was concentrated to obtain an oil. The obtained oil was purified by silica gel column chromatography. As the developing solvent, a mixed solvent of hexane and ethyl acetate at 20:1 was used. The fraction of the obtained substance was concentrated to obtain 4.5 g of a yellow oil in a yield of 98%. The obtained yellow oil was identified as 4,5-dimethyl-2-phenylpyridine (abbreviation: Hdmppy) by nuclear magnetic resonance (NMR) spectroscopy. The following (h-2) shows the synthesis scheme of Step 2.

[0653] [Chemical formula 36]

[0654]

[0655] <Step 3: Synthesis of bis[2-(4,5-dimethyl-2-pyridinyl-κN 2 )phenyl-κC][2-(6-phenyl-4-pyrimidinyl-κN 3 )phenyl-κC]iridium(III) (abbreviation: [Ir(dppm)(dmppy) 2 )>

[0656] Next, di-μ-chloro-tetrakis[2-(6-phenyl-4-pyrimidinyl-κN 3 )phenyl-κC]diiridium(III) (abbreviation: [Ir(dppm) 2 Cl]2 ) 2.1 g (1.5 mmol) and 300 mL of dichloromethane were placed in a 1000 mL three-necked flask and stirred under a nitrogen stream. A mixed solution of 1.2 g (4.5 mmol) of silver trifluoromethanesulfonate and 150 mL of methanol was added dropwise to the mixed solution, and the mixed solution was stirred in the dark for 16 hours.

[0657] After the reaction at the specified time, the reaction mixture was filtered through diatomaceous earth. The resulting filtrate was concentrated to obtain 2.8 g of a reddish-brown solid. Then, 2.8 g of the obtained solid, 30 mL of ethanol, 30 mL of methanol, and 1.1 g (6.0 mmol) of 4,5-dimethyl-2-phenylpyridine (abbreviation: Hdmppy) synthesized in Step 2 were placed in a 500 mL eggplant-shaped flask and heated and refluxed under a nitrogen stream for 32 hours. After the reaction at the specified time, the reaction mixture was concentrated to obtain a solid. Dichloromethane was added to the obtained solid, and the mixture was filtered through a filter aid with diatomaceous earth, neutral silica gel, and diatomaceous earth stacked in sequence.

[0658] The resulting filtrate was concentrated, and the obtained oil was purified by silica gel column chromatography. As the developing solvent, a mixed solvent of hexane and dichloromethane at a ratio of 2:1 was used. The fractions of the obtained substance were concentrated to obtain a solid. The solid was recrystallized with ethyl acetate / hexane to obtain 0.18 g of a red solid in a yield of 8%. The obtained 0.18 g of solid was heated at 280 °C for 21 hours by gradient sublimation method at a pressure of 2.6 Pa and an argon flow rate of 5.0 mL / min to purify it. After sublimation purification, 0.10 g of the target red solid was obtained with a recovery rate of 56%. The following (h-3) shows the synthesis scheme of Step 3.

[0659] [Chemical formula 37]

[0660]

[0661] The following shows the nuclear magnetic resonance ( 1 1H-NMR) spectroscopic analysis results of the target substance (red solid) obtained in Step 3. Figure 52 Shows 1 1H-NMR spectrum. These results indicate that the organometallic complex [Ir(dppm)(dmppy) 2 represented by the structural formula (118) was obtained in this synthesis example.

[0662] 1 1H-NMR δ (CDCl 3):2.01 (s, 3H), 2.03 (s, 3H), 2.32 (s, 3H), 2.33 (s, 3H), 6.72 (d, 1H), 6.79 - 6.96 (m, 8H), 7.27 (s, 1H), 7.36 (s, 1H), 7.47 - 7.53 (m, 3H), 7.60 - 7.66 (m, 4H), 7.85 (d, 1H), 8.07 (d, 2H), 8.16 (d, 1H), 8.25 (d, 1H).

[0663] Next, the ultraviolet-visible absorption spectrum (hereinafter simply referred to as the "absorption spectrum") and the emission spectrum of the dichloromethane solution of [Ir(dppm)(dmppy) 2 were measured. Using an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550), the dichloromethane solution (0.0152 mmol / L) was placed in a quartz cell, and the absorption spectrum was measured at room temperature. In addition, using an absolute PL quantum yield measurement system (C11347-01 manufactured by Hamamatsu Photonics K.K.), in a glove box (LABstar M13(1250 / 780) manufactured by Bright Corporation), the deoxygenated dichloromethane solution (0.0152 mmol / L) was sealed in a quartz cell under a nitrogen atmosphere, and the emission spectrum was measured at room temperature. Figure 53 The measurement results of the obtained absorption spectrum and emission spectrum are shown, where the horizontal axis represents the wavelength and the vertical axis represents the absorption intensity and the luminescence intensity. In Figure 53 , two solid lines are shown. The thin line represents the absorption spectrum and the thick line represents the emission spectrum. Figure 53 The absorption spectrum in [] is the result obtained by the following method: subtracting the absorbance measured by putting only dichloromethane in a quartz cell from the absorbance measured by putting the dichloromethane solution (0.0152 mmol / L) in a quartz cell.

[0664] As Figure 53 shown, the organometallic complex [Ir(dppm)(dmppy) 2 has an emission peak at 629 nm and red luminescence is observed from dichloromethane.

[0665] [Example 12]

[0666] [Synthesis Example 9]

[0667] In this example, the synthesis method of the organometallic complex, that is, the organometallic complex represented by the structural formula (119) in Embodiment 1 {2-[6-(1,1-dimethylethyl)-4-pyrimidinyl-κN 3Phenyl-κC}bis[2-(4-phenyl-2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(tBuppm)(4dppy) 2 ) synthesis method. Hereinafter, [Ir(tBuppm)(4dppy) 2 structure is shown.

[0668] [Chemical formula 38]

[0669]

[0670] First, 3.5 g of [Ir(4dppy) 2 Cl] 2 (abbreviation) and 250 mL of dichloromethane were placed in a three-necked flask, and the atmosphere in the flask was replaced with nitrogen. A mixed solution of 2.0 g of silver trifluoromethanesulfonate and 30 mL of methanol was added dropwise to this flask, and then stirred at room temperature for 20 hours. The resulting reaction product was filtered through diatomaceous earth. The filtrate was concentrated to obtain a solid. Then, 2.9 g of HtBuppm (abbreviation), 50 mL of 2-ethoxyethanol, and 50 mL of N,N-dimethylformamide (abbreviation: DMF) were added to this solid, and the mixture was refluxed for 15 hours under a nitrogen atmosphere.

[0671] The resulting mixture was concentrated to obtain a solid. The obtained solid was purified by neutral silica gel column chromatography using chloroform and hexane as developing solvents in a ratio of 2:3. And further purified by neutral silica gel column chromatography using dichloromethane and hexane as developing solvents in a ratio of 1:1. The resulting solution was concentrated, and then recrystallized using dichloromethane and methanol to obtain the organometallic complex [Ir(tBuppm)(4dppy) 2 as an orange solid (yield: 27%).

[0672] Under a pressure of 2.7 Pa, 0.12 g of the obtained orange solid was purified by gradient sublimation at an argon flow rate of 5 mL / min and at 305 °C. After sublimation purification, the target orange solid was obtained in a yield of 59%. The following (i) shows the synthesis scheme of the above synthesis method.

[0673] [Chemical formula 39]

[0674]

[0675] Hereinafter, the analysis results of nuclear magnetic resonance ( 1 H-NMR) spectroscopy of the orange solid obtained by the above synthesis method are shown. Figure 54 Shown 11H-NMR spectrum. These results indicate that the organometallic complex represented by Structural Formula (119), [Ir(tBuppm)(4dppy), was obtained in this synthesis example. 2 .

[0676] 1 1H-NMR δ(CDCl 3 3): 1.38 (s, 9H), 6.84 (d, 1H), 6.87 - 6.97 (m, 8H), 7.07 (dd, 1H), 7.16 (dd, 1H), 7.42 - 7.51 (m, 6H), 7.60 (d, 2H), 7.66 - 7.67 (m, 4H), 7.76 - 7.80 (m, 4H), 8.05 (ds, 1H), 8.10 (ds, 1H), 8.26 (ds, 1H). Note that the peak around 5.29 originates from dichloromethane.

[0677] Next, the ultraviolet-visible absorption spectrum (hereinafter simply referred to as the "absorption spectrum") and the emission spectrum of a deoxygenated dichloromethane solution of [Ir(tBuppm)(4dppy) 2 were measured. Using an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, model V550), the absorption spectrum was measured at room temperature with a dichloromethane solution (0.019 mmol / L) placed in a quartz cell. In addition, using an absolute PL quantum yield measurement system (C11347-01 manufactured by Hamamatsu Photonics K.K.), in a glove box (LABstar M13(1250 / 780) manufactured by Bright Corporation), a deoxygenated dichloromethane solution (0.019 mmol / L) was sealed in a quartz cell under a nitrogen atmosphere, and the emission spectrum was measured at room temperature.

[0678] Figure 55 The measurement results of the obtained absorption spectrum and emission spectrum are shown, where the horizontal axis represents the wavelength and the vertical axis represents the absorption intensity and the luminescence intensity. In Figure 55 , two solid lines are shown, the thin line represents the absorption spectrum, and the thick line represents the emission spectrum. Figure 55 The absorption spectrum in

[0679] was obtained by the following method: subtracting the absorbance measured by placing only dichloromethane in a quartz cell from the absorbance measured by placing a dichloromethane solution (0.019 mmol / L) in a quartz cell. Figure 55 As 2 shown, the organometallic complex [Ir(tBuppm)(4dppy)

[0680] Next, liquid chromatography-mass spectrometry (LC-MS) analysis was used to perform mass spectrometry (MS) analysis on [Ir(tBuppm)(4dppy) obtained in this example. 2 .

[0681] In the LC-MS analysis, LC (liquid chromatography) separation was performed using an UltiMate 3000 manufactured by Thermo Fisher Scientific, and mass spectrometry (MS) was performed using a Q Exactive manufactured by Thermo Fisher Scientific.

[0682] In the LC separation, an arbitrary column was used, the column temperature was 40 °C, and the infusion conditions were as follows: The solvent was appropriately selected, and [Ir(tBuppm)(4dppy) 2 was dissolved in an organic solvent to adjust the sample, and the injection volume was 5.0 μL.

[0683] In the MS analysis, targeted MS 2 (Targeted-MS 2 ) method was used to measure the component with m / z = 864.28 of the ions derived from [Ir(tBuppm)(4dppy) 2 . In the targeted MS 2 , the mass range was set to ±2.0 m / z, and detection was performed in the positive mode. The energy (normalized collision energy: NCE) that accelerates the target ion was set to 40 for measurement. Figure 56 The obtained MS spectrum is shown.

[0684] Figure 56 It is shown that the fragment ions of [Ir(tBuppm)(4dppy) 2 were mainly detected around m / z = 653 and 634. Figure 56 The results in 2 show the characteristics of [Ir(tBuppm)(4dppy) 2 derived from, and thus can be regarded as important data for the identification of [Ir(tBuppm)(4dppy)

[0685] The fragment ion near m / z = 653 can be estimated as a cation in the state where tBuppm (abbreviation) detaches from [Ir(tBuppm)(4dppy) 2 . This indicates that [Ir(tBuppm)(4dppy) 2 contains HtBuppm (abbreviation). The fragment ion near m / z = 634 can be estimated as 4dppy (abbreviation) detaching from [Ir(tBuppm)(4dppy) 2Cations in a detached state. This indicates [[Ir(tBuppm)(4dppy) 2 contains H4dppy (abbreviation).

[0686] [Example 13]

[0687] In this example, as a light-emitting element of an embodiment of the present invention, a light-emitting element 6 including [Ir(dppm) 2 (dmppy)](114) whose synthesis method is shown in Example 3 in the light-emitting layer, and a light-emitting element 7 including [Ir(dppm)(dmppy) 2 (118) whose synthesis method is shown in Example 11 in the light-emitting layer are manufactured. Measurement results of the characteristics of these light-emitting elements are shown. Note that in this example, except for the difference in the materials used, the manufacturing methods of the light-emitting elements 6 and 7 are the same as those in Example 5, and the description thereof is omitted here. Hereinafter, the chemical formulas of the materials used in this example are shown.

[0688] [Chemical Formula 40]

[0689]

[0690] 《Manufacture of Light-Emitting Elements 6 and 7》

[0691] Table 6 shows the element structures of the light-emitting element 6 and the light-emitting element 7 manufactured in this example.

[0692] [Table 6]

[0693]

[0694] *2mDBTBPDBq-II:PCBBiF:[Ir(dppm) 2 (mdppy)](0.7:0.3:0.05(20nm)\0.8:0.2:0.05(20nm))

[0695] **2mDBTBPDBq-II:PCBBiF:[Ir(dppm)(mdppy) 2 (0.7:0.3:0.05(20nm)\0.8:0.2:0.05(20nm))

[0696] 《Operating Characteristics of Light-Emitting Elements 6 and 7》

[0697] Next, the operating characteristics of each light-emitting element are measured. In addition, the measurement is carried out at room temperature (an atmosphere where the temperature is maintained at 25 °C).

[0698] Figure 57 、Figure 58 , Figure 59 and Figure 60 respectively show the current density - luminance characteristics, voltage - luminance characteristics, luminance - current efficiency characteristics, and voltage - current characteristics of the light - emitting elements 6 and 7.

[0699] The following Table 7 shows the initial values of the main characteristics of each light - emitting element near 1000 cd / m 2 .

[0700] [Table 7]

[0701]

[0702] Figure 61 shows the emission spectra of the light - emitting elements when a current is applied at a current density of 2.5 mA / cm 2 . In Figure 61 , the emission spectra of the light - emitting elements 6 and 7 each have a peak near 605 nm, which may originate from the red - orange emission of the organometallic complex [Ir(dppm) 2 (dmppy)] for the EL layer of the light - emitting element 6 and the organometallic complex [Ir(dppm)(dmppy) 2 for the EL layer of the light - emitting element 7.

[0703] Next, the reliability tests of the above - mentioned light - emitting elements are carried out. Figure 62 shows the results of the reliability tests. In Figure 62 , the vertical axis represents the normalized luminance (%) when the initial luminance is 100%, and the horizontal axis represents the driving time (h) of the element. As the reliability test, a constant - current driving test is carried out at 2 mA.

[0704] Figure 62The results shown indicate that the light-emitting elements 6 and 7 including the organometallic complex according to an embodiment of the present invention each have high reliability. This is probably because: the organometallic complex according to an embodiment of the present invention has a shallow HOMO and a deep LUMO as a whole, and since the HOMO and LUMO are spatially separated because they are distributed on different ligands. In other words, in each organometallic complex used as the light-emitting material of the light-emitting elements 6 and 7, when transporting carriers and when in an excited state, holes are distributed on the ligand with high hole resistance (the first ligand where the HOMO is likely to be distributed), and electrons are distributed on the ligand with high electron resistance (the second ligand where the LUMO is likely to be distributed). Thereby, the stability when transporting carriers and when in an excited state can be increased, and a light-emitting element with a long service life can be manufactured. And, due to such separation of the HOMO and LUMO, the organometallic complex itself can transport both carriers, and thus, in the light-emitting element manufactured using the organometallic complex, the carrier balance can be adjusted, and the recombination region of the light-emitting layer can be prevented from narrowing. This can also be considered as a factor for achieving an increase in the service life.

[0705] In the light-emitting element 7 manufactured using the organometallic complex having two dmppy ligands and one dppm ligand, the effect of increasing the service life is particularly obvious. This indicates that: from the viewpoint of increasing the service life, the presence of the two ligands where the HOMO is distributed and the one ligand where the LUMO is distributed is important. That is, when there are more ligands that can receive holes, the organometallic complex is more stable.

[0706] [Example 14]

[0707] In this example, as the light-emitting element according to an embodiment of the present invention, a light-emitting element 8 including [Ir(tBuppm) 2 (4dppy)](117) whose synthesis method is shown in Example 8 in the light-emitting layer, and a light-emitting element 9 including [Ir(tBuppm)(4dppy) 2 (119) whose synthesis method is shown in Example 12 in the light-emitting layer were manufactured. The measurement results of the characteristics of these light-emitting elements are shown. Note that in this example, except for the point of using different materials, the manufacturing methods of the light-emitting elements 8 and 9 are the same as those in Example 5, and the description thereof is omitted here. Hereinafter, the chemical formulas of the materials used in this example are shown.

[0708] [Chemical Formula 41]

[0709]

[0710] 《Manufacture of Light-Emitting Elements 8 and 9》

[0711] Table 8 shows the element structures of the light-emitting elements 8 and 9 fabricated in this embodiment.

[0712] [Table 8]

[0713]

[0714] *2mDBTBPDBq-II:PCBBiF:[Ir(tBuppm) 2 (4dppy)](0.7:0.3:0.075(20nm)\0.8:0.2:0.075(20nm))

[0715] **2mDBTBPDBq-II:PCBBiF:[Ir(tBuppm)(4dppy) 2 (0.7:0.3:0.075(20nm)\0.8:0.2:0.075(20nm))

[0716] 《Operating Characteristics of Light-Emitting Elements 8 and 9》

[0717] Next, the operating characteristics of each light-emitting element were measured. In addition, the measurements were carried out at room temperature (an atmosphere maintained at 25 °C).

[0718] Figure 63 、 Figure 64 、 Figure 65 and Figure 66 show the current density-luminance characteristics, voltage-luminance characteristics, luminance-current efficiency characteristics, and voltage-current characteristics of the light-emitting elements 8 and 9, respectively.

[0719] The following Table 9 shows the initial values of the main characteristics of each light-emitting element near 1000 cd / m 2 2.

[0720] [Table 9]

[0721]

[0722] Figure 67 shows the emission spectra of the light-emitting elements when a current is applied at a current density of 2.5 mA / cm 2 2. In Figure 67 this, the emission spectra of the light-emitting elements 8 and 9 each have a peak near 605 nm, which may originate from the yellow emission of the organometallic complex [Ir(tBuppm) 2 (4dppy)] for the EL layer of the light-emitting element 8 and the organometallic complex [Ir(tBuppm)(4dppy) 2 for the EL layer of the light-emitting element 9.

[0723] Next, reliability tests of the above-described light-emitting elements were performed. Figure 68 The results of the reliability tests are shown. In Figure 68 , the vertical axis represents the normalized luminance (%) when the initial luminance is 100%, and the horizontal axis represents the driving time (h) of the element. As the reliability test, a constant current driving test was performed at 2 mA.

[0724] Figure 68 The results shown indicate that the light-emitting elements 8 and 9 including the organometallic complex of one embodiment of the present invention each have high reliability. This is probably because: the organometallic complex of one embodiment of the present invention has a shallow HOMO and a deep LUMO as a whole, and since the HOMO and the LUMO are spatially separated because they are distributed on different ligands. In other words, in each of the organometallic complexes used as the light-emitting materials of the light-emitting elements 8 and 9, when transporting carriers and when in the excited state, holes are distributed on the ligand with high hole resistance (the first ligand where the HOMO is likely to be distributed), and electrons are distributed on the ligand with high electron resistance (the second ligand where the LUMO is likely to be distributed). Thereby, the stability when transporting carriers and when in the excited state can be increased, and a light-emitting element with a long service life can be manufactured. Also, due to such separation of the HOMO and the LUMO, the organometallic complex itself can transport both carriers. Therefore, in the light-emitting element manufactured using the organometallic complex, the carrier balance can be adjusted, and narrowing of the recombination region of the light-emitting layer can be prevented. This can also be considered as a factor for achieving an increase in the service life.

[0725] In the light-emitting element 9 manufactured using the organometallic complex having two 4dppy ligands and one tBuppm ligand, the effect of increasing the service life is particularly remarkable. This indicates that: from the viewpoint of increasing the service life, the presence of two ligands where the HOMO is distributed and one ligand where the LUMO is distributed is important. That is, when there are more ligands that can accept holes, the organometallic complex is more stable.

[0726] Symbol Explanation

[0727] 101: First electrode, 102: EL layer, 103: Second electrode, 111: Hole injection layer, 112: Hole transport layer, 113: Light-emitting layer, 114: Electron transport layer, 115: Electron injection layer, 201: First electrode, 202(1): First EL layer, 202(2): Second EL layer, 202(n - 1): (n - 1)th EL layer, 202(n): nth EL layer, 204: Second electrode, 205: Charge generation layer, 205(1): First charge generation layer, 205(2): Second charge generation layer, 205(n - 2): (n - 2)th charge generation layer, 205(n - 1): (n - 1)th charge generation layer, 301: Element substrate, 302: Pixel section, 303: Driving circuit section (source line driving circuit), 304a, 304b: Driving circuit section (gate line driving circuit), 305: Sealing material, 306: Sealing substrate, 307: Wiring, 308: Flexible printed circuit (FPC), 309: FET, 310: FET, 312: FET for current control, 313a, 313b First electrode (anode), 314: Insulator, 315: EL layer, 316: Second electrode (cathode), 317a, 317b: Light-emitting element, 318: Space, 320a, 320b: Conductive film, 321, 322: Region, 323: Surrounding wiring, 324: Colored layer (color filter), 325: Black layer (black matrix), 326, 327, 328: FET, 401: Substrate, 402: First electrode, 403a, 403b, 403c: EL layer, 404: Second electrode, 405: Light-emitting element, 406: Insulating film, 407: Partition wall, 900: Substrate, 901: First electrode, 902: EL layer, 903: Second electrode, 911: Hole injection layer, 912: Hole transport layer, 913: Light-emitting layer, 914: Electron transport layer, 915: Electron injection layer, 2000: Touch screen, 2000': Touch screen, 2501: Display panel, 2502R: Pixel, 2502t: Transistor, 2503c: Capacitor, 2503g: Scan line driving circuit, 2503t: Transistor, 2509: FPC, 2510: Substrate, 2511: Wiring, 2519: Terminal, 2521: Insulating layer, 2528: Insulator, 2550R: Light-emitting element, 2560: Sealing layer, 2567BM: Light-shielding layer, 2567p: Anti-reflection layer, 2567R: Coloring layer, 2570: Substrate, 2590: Substrate, 2591: Electrode, 2592: Electrode, 2593: Insulating layer, 2594: Wiring, 2595: Touch sensor, 2597: Adhesive layer, 2598: Wiring, 2599: Terminal, 2601: Pulse voltage output circuit, 2602: Current detection circuit, 2603: Capacitor, 2611: Transistor, 2612: Transistor, 2613: Transistor, 2621: Electrode, 2622: Electrode,3200: Substrate, 3201: Cathode, 3202: EL layer, 3203: Anode, 3213: Light-emitting layer, 3214: Electron injection layer, 3215: Hole transport layer, 3216: Hole injection layer, 3217: Insulator, 3300: Head, 3301a: Jetting part, 3301c: Jetting part, 3302a: Piezoelectric element, 3302c: Piezoelectric element, 3303a: Ink, 3303c: Ink, 4000: Lighting device, 4001: Substrate, 4002: Light-emitting element, 4003: Substrate, 4004: Electrode, 4005: EL layer, 4006: Electrode, 4007: Electrode, 4008: Electrode, 4009: Auxiliary wiring, 4010: Insulating layer, 4011: Sealing substrate, 4012: Sealing material, 4013: Desiccant, 4015: Diffusion plate, 4100: Lighting device, 4200: Lighting device, 4201: Substrate, 4202: Light-emitting element, 4204: Electrode, 4205: EL layer, 4206: Electrode, 4207: Electrode, 4208: Electrode, 4209: Auxiliary wiring, 4210: Insulating layer, 4211: Sealing substrate, 4212: Sealing material, 4213: Barrier film, 4214: Planarization film, 4215: Diffusion plate, 4300: Lighting device, 5101: Lamp, 5102: Wheel hub, 5103: Car door, 5104: Display part, 5105: Steering wheel, 5106: Gear lever, 5107: Seat, 5108: Interior rearview mirror, 7100: Television device, 7101: Housing, 7103: Display part, 7105: Bracket, 7107: Display part, 7109: Operation key, 7110: Remote operation machine, 7201: Main body, 7202: Housing, 7203: Display part, 7204: Keyboard, 7205: External connection port, 7206: Pointing device, 7302: Housing, 7304: Display part, 7305: Icon indicating time, 7306: Other icons, 7311: Operation button, 7312: Operation button, 7313: Connection terminal, 7321: Watchband, 7322: Watchband buckle, 7400: Mobile phone, 7401: Housing, 7402: Display part, 7403: Operation button, 7404: External connection part, 7405: Speaker, 7406: Microphone, 7407: Camera, 7500(1), 7500(2): Housing, 7501(1), 7501(2): First surface, 7502(1), 7502(2): Second surface, 8001: Lighting device, 8002: Lighting device, 8003: Lighting device, 9310: Portable information terminal, 9311: Display part, 9312: Display area, 9313: Hinge, 9315: Housing.,

[0728] This application is based on Japanese Patent Application No. 2016-074489, filed with the Japan Patent Office on April 1, 2016, the entire contents of which are incorporated herein by reference.

Claims

1. A light-emitting device, the light-emitting device including an EL layer between a pair of electrodes, wherein, the EL layer includes at least a light-emitting layer, the light-emitting layer contains an organometallic complex, and the organometallic complex is represented by the general formula (G1): R 1 to R 15 each independently represents hydrogen, an alkyl group having 1 to 6 carbon atoms, an unsubstituted aryl group having 6 to 13 carbon atoms, or an unsubstituted heteroaryl group having 3 to 12 carbon atoms.

2. A light-emitting device, the light-emitting device including an EL layer between a pair of electrodes, wherein, the EL layer includes at least a light-emitting layer, the light-emitting layer contains an organometallic complex, and the organometallic complex is represented by the general formula (G2): n is 1 or 2, And, R 1 to R 4 and R 6 to R 15 each independently represents any one of hydrogen, an alkyl group having 1 to 6 carbon atoms, an unsubstituted aryl group having 6 to 13 carbon atoms, or an unsubstituted heteroaryl group having 3 to 12 carbon atoms.

3. The light-emitting device according to claim 1 or 2, wherein the organometallic complex does not include a polycycle.

4. A light-emitting device, the light-emitting device including an EL layer between a pair of electrodes, wherein, the EL layer includes at least a light-emitting layer, the light-emitting layer contains an organometallic complex, and the organometallic complex is represented by any one of structural formulas (100), (102), (114), and (117) to (120):

5. The light-emitting device according to claim 2, wherein the organometallic complex is represented by structural formula (200) or (300):

6. The light-emitting device according to claim 1 or 2, wherein, R 6 represents tert-butyl.

7. An electronic device, including a microphone, a camera, an operation button, an external connection portion, or a speaker; and the light-emitting device according to any one of claims 1, 2, and 4.

8. An electronic device, including a housing or a touch sensor; and the light-emitting device according to any one of claims 1, 2, and 4.

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