JP6584073B2 - Organometallic complex and light emitting device - Google Patents

Description

One embodiment of the present invention relates to an organometallic complex. In particular, the present invention relates to an organometallic complex that can convert energy in a triplet excited state into light emission. In addition, the present invention relates to a light-emitting element, a light-emitting device, an electronic device, and a lighting device each 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. Alternatively, one embodiment of the present invention relates to a process, a machine, a manufacture, or a composition (composition of matter). Therefore, the technical field of one embodiment of the present invention disclosed in this specification more specifically includes a semiconductor device, a display device, a liquid crystal display device, a power storage device, a memory device, an imaging device, a driving method thereof, or An example of the production method is as follows.

A light emitting mechanism of an organic EL element (light emitting element) formed by sandwiching an EL layer containing a light emitting substance between a pair of electrodes is a carrier injection type. That is, when a voltage is applied between the electrodes, electrons and holes injected from the electrodes are recombined to make the luminescent substance in an excited state and emit light when the excited state returns to the ground state. The types of excited states include a singlet excited state (S ^* ) and a triplet excited state (T ^* ). Light emitted from the singlet excited state is fluorescent, and light emitted from the triplet excited state is phosphorescent. being called. In addition, the statistical generation ratio of the light emitting elements is considered to be S ^* : T ^* = 1: 3.

Among the above luminescent substances, compounds that can convert energy in singlet excited state into light emission are called fluorescent compounds (fluorescent materials), and can convert energy in triplet excited state into light emission. Such a compound is called a phosphorescent compound (phosphorescent material).

Therefore, the theoretical limit of the internal quantum efficiency (ratio of photons generated with respect to injected carriers) in a light emitting device using a fluorescent material is 25% on the basis of S ^* : T ^* = 1: 3. However, the theoretical limit of the internal quantum efficiency in a light-emitting element using a phosphorescent material is 75%.

That is, it is possible to obtain higher efficiency in a light emitting element using a phosphorescent material than in a light emitting element using a fluorescent material. Accordingly, various types of phosphorescent materials have been actively developed in recent years. In particular, due to the high phosphorescent quantum yield, organometallic complexes having iridium or the like as a central metal have attracted attention (see, for example, Patent Document 1 and Patent Document 2).

Japanese Patent Laid-Open No. 2007-137872 JP 2008-069221 A

As reported in Patent Documents 1 and 2 described above, phosphorescent materials exhibiting various emission colors are being developed. However, development of new materials with higher efficiency is desired.

Therefore, in one embodiment of the present invention, an organometallic complex which has favorable light emission efficiency and heat resistance and exhibits yellow light emission is provided as a novel substance. In addition, a light-emitting element with high current efficiency is provided. In addition, a light-emitting device, an electronic device, or a lighting device with low power consumption is provided.

One embodiment of the present invention includes a metal and a ligand, and the ligand includes a pyrimidine ring and three substituted or unsubstituted groups bonded to the 2-position, the 4-position, and the 5-position of the pyrimidine ring, respectively. An organometallic complex having a phenyl group and bonded to a metal at each of the first position of the pyrimidine ring and the second position of the phenyl group bonded at the second position of the pyrimidine ring.

Another embodiment of the present invention includes a first ligand and a second ligand that are bonded to a metal, and the first ligand includes a pyrimidine ring and a pyrimidine ring 2. A mono-anionic bidentate chelate coordination having a β-diketone structure, with three substituted or unsubstituted phenyl groups bonded respectively at positions 4, 4 and 5 A monoanionic bidentate chelate ligand having a carboxyl group, a monoanionic bidentate chelate ligand having a phenolic hydroxyl group, or a monoanionic bidentate ligand in which the two coordination elements are both nitrogen An organic ligand characterized in that it is a bidentate chelate ligand and binds to a metal at the first position of the pyrimidine ring of the first ligand and at the second position of the phenyl group bonded at the 2-position of the pyrimidine ring. It is a metal complex.

In each of the above structures, the metal is iridium or platinum.

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

However, in General Formula (G1), M represents iridium or platinum, and R ^{1 to} R ¹⁵ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

Another embodiment of the present invention is an organometallic complex represented by General Formula (G2) below.

However, in General Formula (G2), M represents iridium or platinum, and L represents a monoanionic ligand. R ^{1 to} R ¹⁵ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. When M is iridium, m represents 3 and n represents 1 to 3, and when M is platinum, m represents 2 and n represents 1 or 2.

In the general formula (G2), the monoanionic ligand is a monoanionic bidentate chelate ligand having a β-diketone structure, a monoanionic bidentate chelate ligand having a carboxyl group, A monoanionic bidentate chelate ligand having a phenolic hydroxyl group or a monoanionic bidentate chelate ligand in which both two coordination elements are nitrogen is preferable. In particular, a monoanionic bidentate chelate ligand having a β-diketone structure is preferable because the β-diketone structure increases the solubility of the organometallic complex in an organic solvent and facilitates purification. Further, it is preferable to have a β-diketone structure because an organometallic complex having high luminous efficiency can be obtained. Moreover, there exists an advantage that sublimation property increases and it has the outstanding vapor deposition performance by having (beta) -diketone structure.

The monoanionic ligand is preferably any one of the general formulas (L1) to (L7). These ligands are effective because they have high coordination ability and can be obtained at low cost.

In the ^formula, R ^{71 to R 109} are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a halogen group, a vinyl group, a substituted or unsubstituted haloalkyl having 1 to 6 carbon atoms Represents a group, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, or a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms. A ^{1 to} A ³ each independently represent nitrogen, sp ² hybrid carbon bonded to hydrogen, or sp ² carbon having a substituent, and the substituent is an alkyl group having 1 to 6 carbon atoms or a halogen group. Represents a haloalkyl group having 1 to 6 carbon atoms or a phenyl group.

Another embodiment of the present invention is an organometallic complex represented by General Formula (G3) below.

However, in General Formula (G3), R ^{1 to} R ¹⁵ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. R ^{20 to} R ²² are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a halogen group, a vinyl group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted group; It represents an unsubstituted alkoxy group having 1 to 6 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms.

Another embodiment of the present invention is an organometallic complex represented by General Formula (G4) below.

However, in General Formula (G4), R ^{1 to} R ¹⁵ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

Another embodiment of the present invention is an organometallic complex represented by the following structural formula (100).

Another embodiment of the present invention is an organometallic complex represented by the following structural formula (101).

Another embodiment of the present invention is an organometallic complex represented by the following structural formula (200).

In addition, since the organometallic complex which is one embodiment of the present invention can emit phosphorescence, that is, can emit light from a triplet excited state and can emit light, it can be used for a light-emitting element. This makes it possible to increase the efficiency and is very effective. Therefore, a light-emitting element using the organometallic complex which is one embodiment of the present invention is included in one embodiment of the present invention.

One embodiment of the present invention includes not only a light-emitting device having a light-emitting element but also a lighting device having a light-emitting device. Therefore, the light-emitting device in this specification refers to an image display device or a light source (including a lighting device). Also, a connector such as a flexible printed circuit (FPC) or TCP (Tape Carrier Package) attached to the light emitting device, a module provided with a printed wiring board at the end of the TCP, or a COG (Chip On Glass) attached to the light emitting element. It is assumed that the light emitting device also includes all modules on which IC (integrated circuit) is directly mounted by the method.

One embodiment of the present invention can provide an organometallic complex as a novel substance that has favorable emission efficiency and heat resistance and exhibits yellow emission (emission wavelength: around 555 nm) as an emission color. In addition, an organometallic complex whose emission spectrum is broad can be provided. Note that a light-emitting element with high current efficiency can be provided by using a new organometallic complex. In addition, a light-emitting device, an electronic device, or a lighting device with low power consumption can be provided. Alternatively, a novel material, a novel substance, a novel light-emitting device, a novel display device, a novel electronic device, or a novel lighting device can be provided. Note that the description of these effects does not disturb the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. It should be noted that the effects other than these are naturally obvious from the description of the specification, drawings, claims, etc., and it is possible to extract the other effects from the descriptions of the specification, drawings, claims, etc. It is.

4A and 4B illustrate a structure of a light-emitting element. 4A and 4B illustrate a structure of a light-emitting element. FIG. 6 illustrates a light-emitting device. 6A and 6B illustrate electronic devices. 6A and 6B illustrate electronic devices. The figure explaining an illuminating device. The figure explaining an illuminating device. The figure which shows an example of a touch panel. The figure which shows an example of a touch panel. The figure which shows an example of a touch panel. The block diagram and timing chart of a touch sensor. The circuit diagram of a touch sensor. ¹ H-NMR chart of an organometallic complex represented by Structural Formula (100). The ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by Structural Formula (100). The figure which shows the LC-MS measurement result of the organometallic complex shown to Structural formula (100). ¹ H-NMR chart of an organometallic complex represented by Structural Formula (101). The ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by Structural Formula (101). The figure which shows the LC-MS measurement result of the organometallic complex shown to Structural formula (101). ¹ H-NMR chart of an organometallic complex represented by Structural Formula (200). The ultraviolet-visible absorption spectrum and emission spectrum of the organometallic complex represented by Structural Formula (200). The figure which shows the LC-MS measurement result of the organometallic complex shown to Structural formula (200). 3A and 3B illustrate a light-emitting element. FIG. 14 shows current density-luminance characteristics of Light-emitting Element 1. FIG. 6 shows voltage-luminance characteristics of the light-emitting element 1. FIG. 11 shows luminance-current efficiency characteristics of the light-emitting element 1. FIG. 6 shows voltage-current characteristics of the light-emitting element 1. FIG. 9 shows an emission spectrum of the light-emitting element 1. FIG. 11 shows current density-luminance characteristics of Light-Emitting Element 2. FIG. 11 shows voltage-luminance characteristics of the light-emitting element 2; FIG. 14 shows luminance-current efficiency characteristics of the light-emitting element 2; FIG. 11 shows voltage-current characteristics of the light-emitting element 2; FIG. 9 shows an emission spectrum of the light-emitting element 2; FIG. 9 shows reliability of the light-emitting element 2; FIG. 11 shows current density-luminance characteristics of Light-Emitting Element 3. FIG. 10 shows voltage-luminance characteristics of the light-emitting element 3; FIG. 11 shows luminance-current efficiency characteristics of the light-emitting element 3; FIG. 11 shows voltage-current characteristics of the light-emitting element 3; FIG. 6 shows an emission spectrum of the light-emitting element 3.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and various changes can be made in form and details without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

Note that the terms “film” and “layer” can be interchanged with each other depending on the case or circumstances. For example, the term “conductive layer” may be changed to the term “conductive film”. Alternatively, for example, the term “insulating film” may be changed to the term “insulating layer” in some cases.

(Embodiment 1)
In this embodiment, an organometallic complex which is one embodiment of the present invention will be described.

The organometallic complex which is one embodiment of the present invention includes a metal and a ligand, and the ligand includes three pyrimidine rings that are bonded to the pyrimidine ring at the 2-position, the 4-position, and the 5-position, respectively. An organometallic complex having a substituted or unsubstituted phenyl group, wherein the organometallic complex is bonded to a metal at each of the 1-position of the pyrimidine ring and the 2-position of the phenyl group bonded at the 2-position of the pyrimidine ring. is there. Note that one embodiment of the organometallic complex described in this embodiment is an organometallic complex having a structure represented by the following general formula (G1).

In General Formula (G1), M represents iridium or platinum, and R ^{1 to} R ¹⁵ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

One embodiment of the organometallic complex described in this embodiment is an organometallic complex represented by General Formula (G2) below.

In General Formula (G2), M represents iridium or platinum, and L represents a monoanionic ligand. R ^{1 to} R ¹⁵ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. When M is iridium, m represents 3 and n represents 1 to 3, and when M is platinum, m represents 2 and n represents 1 or 2.

Note that the monoanionic ligand in the general formula (G2) is a monoanionic bidentate chelate ligand having a β-diketone structure, a monoanionic bidentate chelate ligand having a carboxyl group, or phenol. A monoanionic bidentate chelate ligand having an ionic hydroxyl group or a monoanionic bidentate chelate ligand in which the two coordination elements are both nitrogen is preferable. In particular, a monoanionic bidentate chelate ligand having a β-diketone structure is preferred.

Specifically, the monoanionic ligand is preferably any one of the general formulas (L1) to (L7).

In the ^formula, R ^{71 to R 109} are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a halogen group, a vinyl group, a substituted or unsubstituted haloalkyl having 1 to 6 carbon atoms Represents a group, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, or a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms. A ^{1 to} A ³ each independently represent nitrogen, sp ² hybrid carbon bonded to hydrogen, or sp ² carbon having a substituent, and the substituent is an alkyl group having 1 to 6 carbon atoms or a halogen group. Represents a haloalkyl group having 1 to 6 carbon atoms or a phenyl group.

Note that the organometallic complex which is one embodiment of the present invention has a structure in which, in the pyrimidine ring of the ligand, bonds to three substituted or unsubstituted phenyl groups at the 2-position, 4-position, and 5-position of the pyrimidine ring, respectively. Have In this manner, the structure in which three phenyl groups are bonded to the pyrimidine ring can improve the heat resistance of the organometallic complex, so that the reliability of the element can be improved when used in a light-emitting element. it can. In addition, since the emission efficiency can be increased by including a pyrimidine ring, a yellow light-emitting material with high emission efficiency can be obtained with the organometallic complex which is one embodiment of the present invention.

Another embodiment of the present invention is an organometallic complex represented by General Formula (G3) below.

In General Formula (G3), R ^{1 to} R ¹⁵ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. R ^{20 to} R ²² are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a halogen group, a vinyl group, a substituted or unsubstituted haloalkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted group; It represents an unsubstituted alkoxy group having 1 to 6 carbon atoms or a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms.

Another embodiment of the present invention is an organometallic complex represented by General Formula (G4) below.

In General Formula (G4), R ^{1 to} R ¹⁵ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

The above general formula (G1), (G2), (G3), (G4) in ^the, specific examples of the alkyl group having 1 to 6 carbon atoms in R 1 ^{to R 15} or ^R 20 ^{to R 22} are methyl Group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, hexyl group, isohexyl Group, sec-hexyl group, tert-hexyl group, neohexyl group, 3-methylpentyl group, 2-methylpentyl group, 2-ethylbutyl group, 1,2-dimethylbutyl group, 2,3-dimethylbutyl group, etc. It is done.

Next, specific structural formulas of the organometallic complex which is one embodiment of the present invention described above are shown below. However, the present invention is not limited to these.

The structural formulas (100) to (114), the structural formulas (200) to (202), the structural formula (300), the structural formula (301), the structural formula (400), and the structural formula (401). An organometallic complex is a novel substance that can emit phosphorescence. Note that these substances may have geometric isomers and stereoisomers depending on the type of the ligand, but the organometallic complex which is one embodiment of the present invention includes all of these isomers.

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

<< Method for Synthesizing Pyrimidine Derivatives Represented by General Formula (G0) >>
First, an example of a synthesis method of a pyrimidine derivative represented by the following general formula (G0) will be described.

In General Formula (G0), R ^{1 to} R ¹⁵ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

A synthesis scheme (A) of the pyrimidine derivative represented by the general formula (G0) is shown below. Note that in Synthesis Scheme (A), Q ^{1 to} Q ³ represent halogen.

In the above synthesis scheme (A), the pyrimidine derivative represented by the general formula (G0) couples the halogenated pyrimidine compound (A1) to the boronic acids (A2), (A2 ′), and (A2 ″). Can be obtained. Depending on the type of halogen represented by Q ^{1 to} Q ³ , the reaction with boronic acid can be arbitrarily selected in order, or can proceed simultaneously. The boronic acid may be a boronic acid ester or a cyclic triol borate salt.

Since the above-mentioned compounds (A1), (A2), (A2 ′) and (A2 ″) are commercially available or can be synthesized, the pyrimidine derivatives represented by the general formula (G0) Can synthesize many types. Therefore, the organometallic complex which is one embodiment of the present invention has a feature that the variation of the ligand is abundant.

<< Method for Synthesizing Organometallic Complex of One Embodiment of the Present Invention Represented by General Formula (G2) >>
Next, a method for synthesizing the organometallic complex which is one embodiment of the present invention represented by the general formula (G2) and is formed using the pyrimidine derivative represented by the general formula (G0) will be described.

Note that in General Formula (G2), M represents iridium or platinum. When M is iridium, m represents 3 and n represents 2. When M is platinum, m represents 2 and n represents 1.

First, a synthesis scheme (B-1) of the binuclear complex (P) is shown below.

Note that in Synthesis Scheme (B-1), M represents iridium or platinum. When M is iridium, m represents 3 and n represents 2. When M is platinum, m represents 2 and n represents 1.

As shown in the above synthesis scheme (B-1), the binuclear complex (P) includes a halogen-containing metal compound (such as palladium chloride, iridium chloride, iridium bromide, iridium iodide, potassium tetrachloroplatinate) and the like. Using a pyrimidine derivative represented by the formula (G0) and heating in an inert gas atmosphere, it is a kind of organometallic complex having a structure cross-linked with halogen, and is a novel compound of a multinuclear complex ( P) can be obtained. In this case, an alcohol solvent (glycerol, ethylene glycol, 2-methoxyethanol, 2-ethoxyethanol, etc.), a mixed solvent of one or more alcohol solvents and water, or the like may be used.

Moreover, there is no limitation in particular as a heating means in a synthesis scheme (B-1), You may use an oil bath, a sand bath, or an aluminum block. Moreover, it is also possible to use a microwave as a heating means.

Further, as shown in the following synthesis scheme (B-2), the dinuclear complex (P) obtained by the above-mentioned synthesis scheme (B-1) and the monoanionic ligand raw material HL are converted into an inert gas. By reacting in an atmosphere, the proton of HL is eliminated, L is coordinated to the central metal, and the organometallic complex which is one embodiment of the present invention represented by General Formula (G2) is obtained.

Note that in Synthesis Scheme (B-2), M represents iridium or platinum, L represents a monoanionic ligand, Q represents halogen, and R ^{1 to} R ¹⁵ each independently represent hydrogen or A substituted or unsubstituted alkyl group having 1 to 6 carbon atoms is represented.

In the case of the synthesis scheme (B-2), the heating means is not particularly limited, and an oil bath, a sand bath, or an aluminum block may be used. Moreover, it is also possible to use a microwave as a heating means.

In addition, the monoanionic ligand L in the general formula (G2) is a monoanionic bidentate chelate ligand having a beta diketone structure, a monoanionic bidentate chelate ligand having a carboxyl group, A monoanionic bidentate chelate ligand having a phenolic hydroxyl group or a monoanionic bidentate chelate ligand in which both two coordination elements are nitrogen is preferable. In particular, a monoanionic bidentate chelate ligand having a beta diketone structure is preferable because the beta diketone structure increases the solubility of the organometallic complex in an organic solvent and facilitates purification. Further, it is preferable to have a beta diketone structure because an organometallic complex having high luminous efficiency can be obtained. Moreover, sublimation property increases by having a beta diketone structure, and there exists an advantage that it is excellent in vapor deposition performance.

The monoanionic ligand is preferably any one of the general formulas (L1) to (L7). These ligands are effective because they have high coordination ability and can be obtained at low cost.

In the ^formula, R ^{71 to R 109} are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a halogen group, a vinyl group, a substituted or unsubstituted haloalkyl having 1 to 6 carbon atoms Represents a group, a substituted or unsubstituted alkoxy group having 1 to 6 carbon atoms, or a substituted or unsubstituted alkylthio group having 1 to 6 carbon atoms. A ^{1 to} A ³ each independently represent nitrogen, sp ² hybrid carbon bonded to hydrogen, or sp ² carbon having a substituent, and the substituent is an alkyl group having 1 to 6 carbon atoms or a halogen group. Represents a haloalkyl group having 1 to 6 carbon atoms or a phenyl group.

In addition, specific examples of the substituted or unsubstituted alkyl group having 1 to 6 carbon atoms in R ¹ and R ² include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, neohexyl group, 3-methylpentyl group, 2 -Methylpentyl group, 2-ethylbutyl group, 1,2-dimethylbutyl group, 2,3-dimethylbutyl group and the like can be mentioned.

In addition, in the above general formula (G2), synthesis of an organometallic complex having a structure having no monoanionic ligand represented by L, that is, an organometallic complex represented by the following general formula (G2 ′) An example of the method will be described.

Note that in the general formula (G2 ′), M represents iridium or platinum. When M is iridium, n represents 3. When M is platinum, n represents 2.

A synthesis scheme (C) of the general formula (G2 ′) is shown below.

Note that in Synthesis Scheme (C), M represents iridium or platinum. When M is iridium, n represents 3. When M is platinum, n represents 2. R ^{1 to} R ¹⁵ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.

As shown in the synthesis scheme (C), the organometallic complex having the structure represented by the general formula (G2 ′) is a halogen-containing iridium or platinum metal compound (iridium chloride hydrate, ammonium hexachloroiridate, Potassium tetrachloroplatinate, etc.) or a raw material complex compound of iridium or platinum (acetylacetonato complex, diethylsulfide complex, etc.) and a pyrimidine derivative represented by the general formula (G0) are mixed and then heated. Can be obtained.

Note that in the above heating process, an iridium or platinum metal compound containing halogen, or an organometallic complex compound of iridium or platinum and a pyrimidine derivative represented by the general formula (G0) are mixed with an alcohol solvent (glycerol, ethylene Glycol, 2-methoxyethanol, 2-ethoxyethanol and the like).

As described above, the example of the method for synthesizing the organometallic complex which is one embodiment of the present invention has been described, but the present invention is not limited to this and may be synthesized by any other synthesis method.

Note that the organometallic complex which is one embodiment of the present invention described above can emit phosphorescence, and thus can be used as a light-emitting material or a light-emitting substance of a light-emitting element.

In addition, by using the organometallic complex which is one embodiment of the present invention, a light-emitting element, a light-emitting device, an electronic device, or a lighting device with high emission efficiency can be realized. In addition, a light-emitting element, a light-emitting device, an electronic device, or a lighting device with low power consumption can be realized.

Note that one embodiment of the present invention is described in this embodiment. In another embodiment, one embodiment of the present invention will be described. Note that one embodiment of the present invention is not limited thereto. That is, in this embodiment and other embodiments, various aspects of the invention are described; therefore, one embodiment of the present invention is not limited to a particular aspect. For example, although an example in which the present invention is applied to a light-emitting element has been described as one embodiment of the present invention, one embodiment of the present invention is not limited thereto. One embodiment of the present invention may be applied to a device other than a light-emitting element depending on circumstances. One embodiment of the present invention may not be applied to a light-emitting element depending on circumstances. For example, although the example at the time of using iridium was shown as 1 aspect of this invention, 1 aspect of this invention is not limited to this. One embodiment of the present invention may use materials other than iridium. Further, depending on circumstances, one embodiment of the present invention may not use iridium.

The structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 2)
In this embodiment, a light-emitting element using the organometallic complex described in Embodiment 1 as a light-emitting layer as one embodiment of the present invention will be described with reference to FIGS.

In the light-emitting element described in this embodiment, an EL layer 102 including a light-emitting layer 113 is sandwiched between a pair of electrodes (a first electrode (anode) 101 and a second electrode (cathode) 103). In addition to the light emitting layer 113, the hole 102 is formed to include a hole (or hole) injection layer 111, a hole (or hole) transport layer 112, an electron transport layer 114, an electron injection layer 115, and the like.

When a voltage is applied to such a light emitting element, holes injected from the first electrode side and electrons injected from the second electrode side recombine in the light emitting layer, and energy generated thereby. As a result, a light-emitting substance such as an organometallic complex contained in the light-emitting layer emits light.

Note that the hole-injection layer 111 in the EL layer 102 includes a substance having a high hole-transport property and an acceptor substance, and holes are extracted by extraction of electrons from the substance having a high hole-transport property by the acceptor substance. (Hole) occurs. Accordingly, holes are injected from the hole injection layer 111 into the light emitting layer 113 through the hole transport layer 112.

Specific examples for manufacturing the light-emitting element described in this embodiment will be described below.

For the first electrode (anode) 101 and the second electrode (cathode) 103, a metal, an alloy, an electrically conductive compound, a mixture thereof, or the like can be used. Specifically, indium oxide-tin oxide (Indium Tin Oxide), indium oxide-tin oxide containing silicon or silicon oxide, indium zinc oxide (Indium Zinc Oxide), indium oxide containing tungsten oxide and zinc oxide , Gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd) In addition to titanium (Ti), elements belonging to Group 1 or Group 2 of the periodic table of elements, that is, alkali metals such as lithium (Li) and cesium (Cs), and calcium (Ca) and strontium (Sr) Alkaline earth metals, magnesium (Mg), and alloys containing them (MgAg, AlLi , Europium (Eu), ytterbium (Yb), an alloy containing these can be used, such as other graphene like. Note that the first electrode (anode) 101 and the second electrode (cathode) 103 can be formed by, for example, a sputtering method, an evaporation method (including a vacuum evaporation method), or the like.

As a substance having a high hole-transport property used for the hole-injection layer 111 and the hole-transport layer 112, for example, 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 '-Bifluoren-2-yl) -N-phenylami An aromatic amine compound such as biphenyl (abbreviation: BSPB), 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-phenylcarbazole- 3-yl) amino] -9-phenylcarbazole (abbreviation: PCzPCN1) and the like. In addition, 4,4′-di (N-carbazolyl) biphenyl (abbreviation: CBP), 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene (abbreviation: TCPB), 9- [4- ( Carbazole derivatives such as 10-phenyl-9-anthracenyl) phenyl] -9H-carbazole (abbreviation: CzPA), and the like can be used. The substances described here are mainly substances having a hole mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that other than these substances, any substance that has a property of transporting more holes than electrons may be used.

Further, 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: Polymer compounds such as Poly-TPD can also be used.

As an acceptor substance used for the hole injection layer 111, an oxide of a metal belonging to Groups 4 to 8 in the periodic table can be given. Specifically, molybdenum oxide is particularly preferable.

The light emitting layer 113 is a layer containing a light emitting substance. Note that as the light-emitting substance, the organometallic complex described in Embodiment 1 can be used, and the layer further includes a substance having triplet excitation energy higher than that of the organometallic complex (guest material) as a host material. Also good. In addition to the light-emitting substance, two kinds of organic compounds (a combination of the above host materials) that can form an exciplex (also referred to as an exciplex) upon recombination of carriers (electrons and holes) in the light-emitting layer Any of them may be included).

Note that examples of organic compounds that can be used for the above two kinds of organic compounds include compounds having an arylamine skeleton such as 2,3-bis (4-diphenylaminophenyl) quinoxaline (abbreviation: TPAQn) and NPB. In addition, CBP, carbazole derivatives such as 4,4 ′, 4 ″ -tris (carbazol-9-yl) triphenylamine (abbreviation: TCTA), bis [2- (2-hydroxyphenyl) pyridinato] zinc (abbreviation) : Znpp ₂ ), bis [2- (2-hydroxyphenyl) benzoxazolate] zinc (abbreviation: Zn (BOX) ₂ ), bis (2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum ( Abbreviations: BAlq), metal complexes such as tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ) are preferable. A polymer compound such as PVK can also be used.

Note that when the light-emitting layer 113 is formed to include the above-described organometallic complex (guest material) and a host material, phosphorescence with high light emission efficiency can be obtained from the light-emitting layer 113.

In addition, the light-emitting layer 113 is not limited to a single-layer structure illustrated in FIG. 1A in the light-emitting element, and may have a stacked structure including two or more layers as illustrated in FIG. However, in this case, each light emission is obtained from each stacked layer. For example, the first light-emitting layer 113 (a1) is configured to obtain fluorescence, and the second light-emitting layer 113 (a2) stacked as the first layer is configured to obtain phosphorescence. That's fine. The order of stacking may be reversed. In addition, the layer that can emit phosphorescence preferably has a structure in which light emission by energy transfer from the exciplex to the dopant can be obtained. As for the emission color, when blue light emission is obtained from one layer, orange light emission or yellow light emission can be obtained from the other layer. Each layer may include a plurality of types of dopants.

Note that in the case where the light-emitting layer 113 has a stacked structure, not only the organometallic complex described in Embodiment 1 but also a light-emitting substance that changes singlet excitation energy into light emission or a light-emitting substance that changes triplet excitation energy into light emission Etc. can be used alone or in combination. In this case, for example, the following can be cited.

Examples of the light-emitting substance that converts singlet excitation energy into light emission include substances that emit fluorescence (fluorescent compounds).

As a substance that emits fluorescence, 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-butylperylene (abbreviation: TBP), 4- (10-phenyl-9-anthryl) -4 '-(9- Enyl-9H-carbazol-3-yl) triphenylamine (abbreviation: PCBAPA), N, N ″-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene) bis [N, N ', N'-triphenyl-1,4-phenylenediamine] (abbreviation: DPABPA), N, 9-diphenyl-N- [4- (9,10-diphenyl-2-anthryl) phenyl] -9H-carbazole- 3-amine (abbreviation: 2PCAPPA), N- [4- (9,10-diphenyl-2-anthryl) phenyl] -N, N ′, N′-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA) , N, N, N ′, N ′, N ″, N ″, N ′ ″, N ′ ″-octaphenyldibenzo [g, p] chrysene-2,7,10,15-tetraa (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- Carba Zol-9-yl) phenyl] -N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N, N, 9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), coumarin 545T, N, N'- Diphenylquinacridone, (abbreviation: DPQd), rubrene, 5,12-bis (1,1′-biphenyl-4-yl) -6,11-diphenyltetracene (abbreviation: BPT), 2- (2- {2- [ 4- (dimethylamino) phenyl] ethenyl} -6-methyl-4H-pyran-4-ylidene) propanedinitrile (abbreviation: DCM1), 2- {2-methyl-6- [2- (2,3,6) , 7-Tetrahydro-1H, 5H-benzo [ij] quinolizin-9-yl) ethenyl] -4H-pyran-4-ylidene} propanedinitrile (abbreviation: DC 2), 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- {2-isopropyl-6- [2- (1,1,7, 7-tetramethyl-2,3,6,7-tetrahydro-1H, 5H-benzo [ij] quinolizin-9-yl) ethenyl] -4H-pyran-4-ylidene} propanedinitrile (abbreviation: DCJTI), 2 -{2-tert-butyl-6- [2- (1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H, 5H-benzo [ij] quinolidin-9-yl) ethenyl ] -4H- Lan-4-ylidene} propanedinitrile (abbreviation: DCJTB), 2- (2,6-bis {2- [4- (dimethylamino) phenyl] ethenyl} -4H-pyran-4-ylidene) propanedinitrile ( Abbreviation: BisDCM), 2- {2,6-bis [2- (8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H, 5H-benzo [ij]. Quinolizin-9-yl) ethenyl] -4H-pyran-4-ylidene} propanedinitrile (abbreviation: BisDCJTM), and the like.

Examples of the light-emitting substance that changes triplet excitation energy into light emission include a substance that emits phosphorescence (phosphorescent compound) and a TADF material (thermally activated delayed fluorescent compound) that exhibits thermally activated delayed fluorescence (TADF). Note that delayed fluorescence in a TADF material refers to light emission having a remarkably long lifetime while having a spectrum similar to that of normal fluorescence. The lifetime is 10 ⁻⁶ seconds or longer, preferably 10 ⁻³ seconds or longer.

As a substance which emits phosphorescence, bis {2- [3 ′, 5′-bis (trifluoromethyl) phenyl] pyridinato-N, C ^{2 ′} } iridium (III) picolinate (abbreviation: [Ir (CF ₃ ppy) ₂ (Pic)]), bis [2- (4 ′, 6′-difluorophenyl) pyridinato-N, C ^{2 ′} ] iridium (III) acetylacetonate (abbreviation: FIracac), tris (2-phenylpyridinato) Iridium (III) (abbreviation: [Ir (ppy) ₃ ]), bis (2-phenylpyridinato) iridium (III) acetylacetonate (abbreviation: [Ir (ppy) ₂ (acac)]), tris (acetyl) Asetonato) (monophenanthroline) terbium (III) _{(abbreviation: [Tb (acac) 3 (} Phen)]), bis (benzo [h] reluctant G) iridium (III) acetylacetonate _{(abbreviation: [Ir (bzq) 2 (} acac)]), bis (2,4-diphenyl-1,3 oxazolato -N, C ^{2 ')} iridium (III) acetylacetonate Nert (abbreviation: [Ir (dpo) ₂ (acac)]), bis {2- [4 ′-(perfluorophenyl) phenyl] pyridinato-N, C ^{2 ′} } iridium (III) acetylacetonate (abbreviation: [ Ir (p-PF-ph) ₂ (acac)]), bis (2-phenylbenzothiazolate-N, C2 ^' ) iridium (III) acetylacetonate (abbreviation: [Ir (bt) ₂ (acac)) ], Bis [2- (2′-benzo [4,5-α] thienyl) pyridinato-N, C ^{3 ′} ] iridium (III) acetylacetonate (abbreviation: [Ir (btp ) ₂ (acac)]), bis (1-phenylisoquinolinato-N, C ^{2 ′} ) iridium (III) acetylacetonate (abbreviation: [Ir (piq) ₂ (acac)]), (acetylacetonato) Bis [2,3-bis (4-fluorophenyl) quinoxalinato] iridium (III) (abbreviation: [Ir (Fdpq) ₂ (acac)]), (acetylacetonato) bis (3,5-dimethyl-2-phenyl) Pyrazinato) iridium (III) (abbreviation: [Ir (mppr-Me) ₂ (acac)]), (acetylacetonato) bis (5-isopropyl-3-methyl-2-phenylpyrazinato) iridium (III ) (Abbreviation: [Ir (mppr-iPr) ₂ (acac)]), (acetylacetonato) bis (2,3,5-triphenylpyrazinato) Iridium (III) (abbreviation: [Ir (tppr) ₂ (acac)]), bis (2,3,5-triphenylpyrazinato) (dipivaloylmethanato) iridium (III) (abbreviation: [Ir ( tppr) ₂ (dpm)]), (acetylacetonato) bis (6-tert-butyl-4-phenylpyrimidinato) iridium (III) (abbreviation: [Ir (tBupppm) ₂ (acac)]), (acetyl Acetonato) bis (4,6-diphenylpyrimidinato) 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-propanedionate) (monophenanthroline) Europium (III) _{(abbreviation: [Eu (DBM) 3 (} Phen)]), tris [1- (2-thenoyl) -3,3,3-trifluoroacetonato] (monophenanthroline) europium (III) (abbreviation : [Eu (TTA) ₃ (Phen)]) and the like.

Examples of the TADF material include fullerene and derivatives thereof, acridine derivatives such as proflavine, and eosin. In addition, metal-containing porphyrins including magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), and the like can be given. Examples of the metal-containing porphyrin include a protoporphyrin-tin fluoride complex (SnF ₂ (Proto IX)), a mesoporphyrin-tin fluoride complex (SnF ₂ (Meso IX)), and a hematoporphyrin-tin fluoride complex (SnF). ₂ (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF ₂ (Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF ₂ (OEP)), etioporphyrin-tin fluoride And a complex (SnF ₂ (Etio I)), octaethylporphyrin-platinum chloride complex (PtCl ₂ OEP), and the like. Furthermore, π-electron rich complex such as 2-biphenyl-4,6-bis (12-phenylindolo [2,3-a] carbazol-11-yl) -1,3,5-triazine (PIC-TRZ) A heterocyclic compound having an aromatic ring and a π-electron deficient heteroaromatic ring can also be used. In addition, a substance in which a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring are directly bonded increases both the donor property of the π-electron rich heteroaromatic ring and the acceptor property of the π-electron deficient heteroaromatic ring. , Because the energy difference between S1 and T1 is small.

The electron-transport layer 114 is a layer that contains a substance having a high electron-transport property (also referred to as an electron-transport compound). The electron-transport layer 114 includes tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq ₃ ), bis (10-hydroxybenzo [h] quinolinato). Beryllium (abbreviation: BeBq ₂ ), bis (2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum (abbreviation: BAlq), bis [2- (2-hydroxyphenyl) benzoxazolate] zinc (abbreviation) : Zn (BOX) ₂ ), bis [2- (2-hydroxyphenyl) benzothiazolate] zinc (abbreviation: Zn (BTZ) ₂ ), and the like can be used. 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis [5- (p-tert-butyl) Phenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD-7), 3- (4′-tert-butylphenyl) -4-phenyl-5- (4 ″ -biphenyl) ) -1,2,4-triazole (abbreviation: TAZ), 3- (4-tert-butylphenyl) -4- (4-ethylphenyl) -5- (4-biphenylyl) -1,2,4-triazole (Abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), 4,4′-bis (5-methylbenzoxazol-2-yl) stilbene (abbreviation: BzOs), etc. Aromatic aromatic compounds can also be used. In addition, 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) Molecular compounds can also be used. The substances mentioned here are mainly substances having an electron mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that any substance other than the above substances may be used for the electron-transport layer 114 as long as it has a property of transporting more electrons than holes.

Further, the electron-transport layer 114 is not limited to a single layer, and may have a structure in which two or more layers including the above substances are stacked.

The electron injection layer 115 is a layer containing a substance having a high electron injection property. The electron injection layer 115 includes an alkali metal, an alkaline earth metal such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF ₂ ), lithium oxide (LiOx), or the like. Compounds can be used. Alternatively, a rare earth metal compound such as erbium fluoride (ErF ₃ ) can be used. Further, electride may be used for the electron injection layer 115. Examples of the electride include a substance obtained by adding a high concentration of electrons to a mixed oxide of calcium and aluminum. Note that the substance forming the electron transport layer 114 described above can also be used.

Alternatively, a composite material obtained by mixing an organic compound and an electron donor (donor) may be used for the electron injection layer 115. Such a composite material is excellent in electron injecting property and electron transporting property because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material excellent in transporting the generated electrons. Specifically, for example, a substance (metal complex, heteroaromatic compound, or the like) constituting the electron transport layer 114 described above is used. Can be used. The electron donor may be any substance that exhibits an electron donating property to the organic compound. Specifically, alkali metals, alkaline earth metals, and rare earth metals are preferable, and lithium, cesium, magnesium, calcium, erbium, ytterbium, and the like can be given. Alkali metal oxides and alkaline earth metal oxides are preferable, and lithium oxide, calcium oxide, barium oxide, and the like can be given. A Lewis base such as magnesium oxide can also be used. Alternatively, an organic compound such as tetrathiafulvalene (abbreviation: TTF) can be used.

Note that the hole injection layer 111, the hole transport layer 112, the light emitting layer 113, the electron transport layer 114, and the electron injection layer 115 described above are formed by a vapor deposition method (including a vacuum vapor deposition method) and a printing method (for example, relief printing). For example, an intaglio printing method, a gravure printing method, a lithographic printing method, a stencil printing method, etc.), an ink jet method, a coating method, or the like.

In the above light-emitting element, current flows due to a potential difference applied between the first electrode 101 and the second electrode 103, and light is emitted by recombination of holes and electrons in the EL layer 102. Then, the emitted light is extracted 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 is a light-transmitting electrode.

Since the light-emitting element described above can emit phosphorescence based on an organometallic complex, a highly efficient light-emitting element can be realized as compared with a light-emitting element using only a fluorescent compound.

Note that the structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 3)
In this embodiment, a light-emitting element having a structure in which an organometallic complex which is one embodiment of the present invention is used for an EL layer as an EL material and includes a plurality of EL layers with a charge generation layer interposed therebetween (hereinafter referred to as a tandem light-emitting element) explain.

As shown in FIG. 2A, the light-emitting element described in this embodiment includes a plurality of EL layers (first EL layer 202 (first EL layer 202 (first electrode 201 and second electrode 204)). 1) a tandem light-emitting element having a second EL layer 202 (2)).

In this embodiment mode, the first electrode 201 is an electrode functioning as an anode, and the second electrode 204 is an electrode functioning as a cathode. Note that the first electrode 201 and the second electrode 204 can have a structure similar to that in Embodiment 2. The plurality of EL layers (the first EL layer 202 (1) and the second EL layer 202 (2)) may both have the same structure as the EL layer described in Embodiment 2. Any one of them may have the same configuration. That is, the first EL layer 202 (1) and the second EL layer 202 (2) may have the same structure or different structures, and the structure is similar to that of Embodiment Mode 2. can do.

Further, a charge generation layer 205 is provided between the plurality of EL layers (the first EL layer 202 (1) and the second EL layer 202 (2)). The charge generation layer 205 has a function of injecting electrons into one EL layer and injecting holes into the other EL layer when voltage is applied to the first electrode 201 and the second electrode 204. In this embodiment mode, when a voltage is applied to the first electrode 201 so that the potential is higher than that of the second electrode 204, electrons are transferred from the charge generation layer 205 to the first EL layer 202 (1). Then, holes are injected into the second EL layer 202 (2).

Note that the charge generation layer 205 has a property of transmitting visible light from the viewpoint of light extraction efficiency (specifically, the charge generation layer 205 has a visible light transmittance of 40% or more). preferable. In addition, the charge generation layer 205 functions even when it has lower conductivity than the first electrode 201 and the second electrode 204.

The charge generation layer 205 has a structure in which an electron acceptor (acceptor) is added to an organic compound having a high hole-transport property, and an electron donor (donor) is added to an organic compound having a high electron-transport property. It may be. Moreover, both these structures may be laminated | stacked.

In the case where an electron acceptor is added to an organic compound having a high hole transporting property, examples of the organic compound having a high hole transporting property include aromatic amine compounds such as NPB, TPD, TDATA, MTDATA, and BSPB. Etc. can be used. The substances described here are mainly substances having a hole mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that other than the above substances, any organic compound that has a property of transporting more holes than electrons may be used.

Examples of the electron acceptor include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F ₄ -TCNQ), chloranil, and the like. In addition, oxides of metals belonging to Groups 4 to 8 in the periodic table can be given. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferable because of their high electron accepting properties. Among these, molybdenum oxide is especially preferable because it is stable in the air, has a low hygroscopic property, and is easy to handle.

On the other hand, in the case where an electron donor is added to an organic compound having a high electron transporting property, examples of the organic compound having a high electron transporting property include Alq, Almq ₃ , BeBq ₂ , BAlq, and the like, a quinoline skeleton or a benzo A metal complex having a quinoline skeleton or the like can be used. In addition, a metal complex having an oxazole-based or thiazole-based ligand such as Zn (BOX) ₂ or Zn (BTZ) ₂ can also be used. In addition to metal complexes, PBD, OXD-7, TAZ, BPhen, BCP, and the like can also be used. The substances mentioned here are mainly substances having an electron mobility of 10 ⁻⁶ cm ² / Vs or higher. Note that other than the above substances, any organic compound that has a property of transporting more electrons than holes may be used.

As the electron donor, an alkali metal, an alkaline earth metal, a rare earth metal, a metal belonging to Groups 2 and 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, or the like is preferably used. An organic compound such as tetrathianaphthacene may be used as an electron donor.

Note that by forming the charge generation layer 205 using the above-described material, an increase in driving voltage in the case where an EL layer is stacked can be suppressed. The charge generation layer 205 can be formed by vapor deposition (including vacuum vapor deposition), printing (eg, relief printing, intaglio printing, gravure printing, lithographic printing, stencil printing, etc.), inkjet It can be formed by using a method such as a method or a coating method alone or in combination.

In this embodiment mode, a light-emitting element having two EL layers is described; however, as shown in FIG. 2B, an n-layer (where n is 3 or more) EL layers (202 (1) to 202). The same applies to a light emitting element in which (n)) is laminated. In the case where a plurality of EL layers are provided between a pair of electrodes as in the light-emitting element according to this embodiment, charge generation layers (205 (1) to 205 (n-1) are provided between the EL layers. ) Can emit light in a high-luminance region while keeping the current density low. Since the current density can be kept low, a long-life element can be realized.

Further, by making the light emission colors of the respective EL layers different, light emission of a desired color can be obtained as the whole light emitting element. For example, in a light-emitting element having two EL layers, a light-emitting element that emits white light as a whole of the light-emitting element by making the emission color of the first EL layer and the emission color of the second EL layer have a complementary relationship It is also possible to obtain The complementary color refers to a relationship between colors that become achromatic when mixed. That is, when light of complementary colors is mixed with each other, white light emission can be obtained. Specifically, a combination in which blue light emission can be obtained from the first EL layer and yellow light emission or orange light emission can be obtained from the second EL layer can be given. In this case, both blue light emission and yellow light emission (or orange light emission) need not be the same fluorescent light emission or phosphorescent light emission, and blue light emission is fluorescent light emission and yellow light emission (or orange light emission) is phosphorescence light emission. Or the reverse combination may be used.

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

Note that the structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 4)
In this embodiment, a light-emitting device including a light-emitting element using the organometallic complex which is one embodiment of the present invention for an EL layer will be described.

Note that the light-emitting device may be a passive matrix light-emitting device or an active matrix light-emitting device. The light-emitting element described in any of the other embodiments can be applied to the light-emitting device described in this embodiment.

In this embodiment, first, an active matrix light-emitting device is described with reference to FIGS.

3A is a top view illustrating the light-emitting device, and FIG. 3B is a cross-sectional view taken along the chain line A-A ′ in FIG. 3A. An active matrix light-emitting device according to this embodiment includes a pixel portion 302 provided over an element substrate 301, a driver circuit portion (source line driver circuit) 303, and a driver circuit portion (gate line driver circuit) 304 ( 304a and 304b). The pixel portion 302, the driver circuit portion 303, and the driver circuit portion 304 are sealed between the element substrate 301 and the sealing substrate 306 with a sealant 305.

Further, on the element substrate 301, external input terminals that transmit external signals (eg, a video signal, a clock signal, a start signal, or a reset signal) and a potential to the driver circuit portion 303 and the driver circuit portion 304 are provided. A lead wiring 307 for connection is provided. In this example, an FPC (flexible printed circuit) 308 is provided as an external input terminal. Although only the FPC is shown here, a printed wiring board (PWB) may be attached to the FPC. The light-emitting device in this specification includes not only a light-emitting device body but also a state in which an FPC or a PWB is attached thereto.

Next, a cross-sectional structure will be described with reference to FIG. A driver circuit portion and a pixel portion are formed over the element substrate 301. Here, a driver circuit portion 303 which is a source line driver circuit and a pixel portion 302 are shown.

The drive circuit unit 303 illustrates a configuration in which the FET 309 and the FET 310 are combined. Note that the FET 309 and the FET 310 included in the driver circuit unit 303 may be formed using a circuit including a unipolar transistor (N-type or P-type only), or an N-type transistor and a P-type transistor may be included. It may be formed of a CMOS circuit including the same. In this embodiment mode, a driver integrated type in which a driver circuit is formed over a substrate is shown; however, this is not necessarily required, and the driver circuit can be formed outside the substrate.

The pixel unit 302 includes a plurality of pixels including a switching FET 311, a current control FET 312, and a first electrode (anode) 313 electrically connected to the wiring (source electrode or drain electrode) of the current control FET 312. It is formed by. In this embodiment mode, the pixel portion 302 is described as an example in which the pixel portion 302 is configured by two FETs, ie, the switching FET 311 and the current control FET 312; however, the present invention is not limited to this. For example, the pixel portion 302 may be a combination of three or more FETs and a capacitor.

As the FETs 309, 310, 311, and 312, for example, staggered or inverted staggered transistors can be applied. As a semiconductor material that can be used for the FETs 309, 310, 311, 312, for example, a group 13 (gallium etc.) semiconductor, a group 14 (silicon etc.) semiconductor, a compound semiconductor, an oxide semiconductor, an organic semiconductor material can be used. . Further, there is no particular limitation on the crystallinity of the semiconductor material, and for example, an amorphous semiconductor film or a crystalline semiconductor film can be used. In particular, an oxide semiconductor is preferably used as the FETs 309, 310, 311, and 312. Examples of the oxide semiconductor include In—Ga oxide and In—M—Zn oxide (M is Al, Ga, Y, Zr, La, Ce, or Nd). By using an oxide semiconductor material with an energy gap of 2 eV or more, preferably 2.5 eV or more, more preferably 3 eV or more as the FETs 309, 310, 311 and 312, the off-state current of the transistor can be reduced.

An insulator 314 is formed so as to cover an end portion of the first electrode 313. Here, the insulator 314 is formed using a positive photosensitive acrylic resin. In this embodiment, the first electrode 313 is used as an anode.

In addition, a curved surface having a curvature is preferably formed on the upper end portion or the lower end portion of the insulator 314. By forming the shape of the insulator 314 as described above, the coverage of a film formed over the insulator 314 can be improved. For example, the material of the insulator 314 can be either a negative photosensitive resin or a positive photosensitive resin, and is not limited to an organic compound, but can be an inorganic compound such as silicon oxide, silicon oxynitride, Silicon nitride or the like can be used.

The light-emitting element 317 has a stacked structure of a first electrode (anode) 313, an EL layer 315, and a second electrode (cathode) 316, and the EL layer 315 is provided with at least a light-emitting layer. In addition to the light-emitting layer, the EL layer 315 can be provided with a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a charge generation layer, and the like as appropriate.

Note that as a material used for the first electrode (anode) 313, the EL layer 315, and the second electrode (cathode) 316, the material described in Embodiment 2 can be used. Although not shown here, the second electrode (cathode) 316 is electrically connected to the FPC 308 which is an external input terminal.

3B illustrates only one light-emitting element 317, it is assumed that a plurality of light-emitting elements are arranged in a matrix in the pixel portion 302. In the pixel portion 302, light emitting elements capable of emitting three types (R, G, and B) of light emission can be selectively formed, so that a light emitting device capable of full color display can be formed. In addition to the light emitting element that can obtain three types of light emission (R, G, B), for example, light emission that can emit light such as white (W), yellow (Y), magenta (M), and cyan (C). An element may be formed. For example, by adding the above-described light emitting elements capable of obtaining several types of light emission (R, G, B) to the light emitting elements capable of obtaining three types of light emission (R, G, B), effects such as improvement in color purity and reduction in power consumption can be obtained. Can do. Alternatively, a light emitting device capable of full color display may be obtained by combining with a color filter. Furthermore, it is good also as a light-emitting device which improved luminous efficiency and reduced power consumption by the combination with a quantum dot.

Further, the sealing substrate 306 is bonded to the element substrate 301 with the sealant 305, whereby the light-emitting element 317 is provided in the space 318 surrounded by the element substrate 301, the sealing substrate 306, and the sealant 305. ing. Note that the space 318 includes a structure filled with the sealant 305 in addition to a case where the space 318 is filled with an inert gas (nitrogen, argon, or the like). In addition, when a sealing material is applied and bonded, it is preferable to perform either UV treatment or heat treatment, or a combination thereof.

Note that an epoxy resin or glass frit is preferably used for the sealant 305. Moreover, it is desirable that these materials are materials that do not transmit moisture and oxygen as much as possible. In addition to a glass substrate and a quartz substrate, a plastic substrate made of FRP (Fiber-Reinforced Plastics), PVF (polyvinyl fluoride), polyester, acrylic, or the like can be used as a material for the sealing substrate 306. When glass frit is used as the sealing material, the element substrate 301 and the sealing substrate 306 are preferably glass substrates from the viewpoint of adhesiveness.

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

In addition, a light-emitting device including a light-emitting element using the organometallic complex which is one embodiment of the present invention for an EL layer can be a passive matrix light-emitting device as well as the above active matrix light-emitting device.

A cross-sectional view of the pixel portion in the case of a passive matrix light-emitting device is shown in FIG.

As illustrated in FIG. 3C, a light-emitting element 350 including a first electrode 352, an EL layer 354, and a second electrode 353 is formed over the substrate 351. Note that the first electrode 352 has an island shape and is formed in a plurality of stripes in one direction. An insulating film 355 is formed so as to fill the first electrode 352 and the end portion of the first electrode 352.

Further, a partition wall 356 made of an insulating material is provided over the insulating film 355. The side wall of the partition wall 356 has an inclination such that the distance between one side wall and the other side wall becomes narrower as it approaches the substrate surface. That is, the cross section in the short side direction of the partition wall 356 has a trapezoidal shape, and the bottom side (the side facing the insulating film 355 in the same direction as the surface direction of the insulating film 355) is the upper side (the surface direction of the insulating film 355). The direction is the same as that of the insulating film 355. In this manner, by providing the partition wall 356, a defect in the light-emitting element due to static electricity or the like can be prevented. Note that the insulating film 355 has an opening in part over the first electrode 352. After the partition wall 356 is formed, the EL layer 354 is formed, whereby the first electrode is formed in the opening. An EL layer 354 in contact with 352 is formed.

Further, after the EL layer 354 is formed, the second electrode 353 is formed. Therefore, the second electrode 353 is formed over the EL layer 354 and, in some cases, over the insulating film 355 without being in contact with the first electrode 352. Note that since the EL layer 354 and the second electrode 353 are formed after the partition 356 is formed, the EL layer 354 and the second electrode 353 are sequentially stacked over the partition 356.

Note that the sealing method can be performed in the same manner as in the case of the active matrix light-emitting device, and thus description thereof is omitted.

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

For example, in this specification and the like, a transistor or a light-emitting element can be formed using various substrates. The kind of board | substrate is not limited to a specific thing. Examples of the substrate include a semiconductor substrate (for example, 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 stainless steel foil, and a tungsten substrate. , A substrate having a tungsten foil, a flexible substrate, a laminated film, a paper containing a fibrous material, or a base film. Examples of the glass substrate include barium borosilicate glass, aluminoborosilicate glass, and soda lime glass. Examples of the flexible substrate, the laminated film, and the base film include the following. For example, there are plastics represented by polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), and polytetrafluoroethylene (PTFE). Another example is a synthetic resin such as acrylic. Alternatively, examples include polypropylene, polyester, polyvinyl fluoride, and polyvinyl chloride. As an example, there are polyamide, polyimide, aramid, epoxy, an inorganic vapor deposition film, papers, and the like. In particular, by manufacturing a transistor using a semiconductor substrate, a single crystal substrate, an SOI substrate, or the like, a transistor with small variation in characteristics, size, or shape, high current capability, and small size can be manufactured. . When a circuit is formed using such transistors, the power consumption of the circuit can be reduced or the circuit can be highly integrated.

Alternatively, a flexible substrate may be used as a substrate, and a transistor or a light-emitting element may be formed directly over the flexible substrate. Alternatively, a separation layer may be provided between the substrate and the transistor or the light-emitting element. The separation layer can be used to separate a semiconductor device from another substrate and transfer it to another substrate after a semiconductor device is partially or entirely completed thereon. At that time, the transistor or the light-emitting element can be transferred to a substrate having poor heat resistance or a flexible substrate. Note that, for example, a structure of a laminated structure of an inorganic film of a tungsten film and a silicon oxide film or a structure in which an organic resin film such as polyimide is formed over a substrate can be used for the above-described release layer.

That is, a transistor or a light-emitting element may be formed using a certain substrate, and then the transistor or the light-emitting element may be transferred to another substrate, and the transistor or the light-emitting element may be provided over another substrate. Examples of a substrate on which a transistor or a light emitting element is transferred include a paper substrate, a cellophane substrate, an aramid film substrate, a polyimide film substrate, a stone substrate, and a wood substrate in addition to the above-described substrate on which the transistor or the light emitting element can be formed. , Cloth substrates (including natural fibers (silk, cotton, hemp), synthetic fibers (nylon, polyurethane, polyester) or recycled fibers (including acetate, cupra, rayon, recycled polyester), leather substrates, rubber substrates, etc.) . By using these substrates, it is possible to form a transistor with good characteristics, a transistor with low power consumption, manufacture a device that is not easily broken, impart heat resistance, reduce weight, or reduce thickness.

Note that the structure described in this embodiment can be combined with any of the structures described in other embodiments as appropriate.

(Embodiment 5)
In this embodiment, examples of various electronic devices completed by applying the light-emitting device which is one embodiment of the present invention will be described with reference to FIGS.

As electronic devices to which the light-emitting device is applied, for example, a television set (also referred to as a television or a television receiver), a monitor for a computer, a digital camera, a digital video camera, a digital photo frame, a mobile phone (a mobile phone, a mobile phone) Also referred to as a telephone device), portable game machines, portable information terminals, sound reproduction devices, large game machines such as pachinko machines, and the like. Specific examples of these electronic devices are shown in FIGS.

FIG. 4A illustrates an example of a television device. In the television device 7100, a display portion 7103 is incorporated in a housing 7101. The display unit 7103 can display an image, and may be a touch panel (input / output device) equipped with a touch sensor (input device). Note that the light-emitting device of one embodiment of the present invention can be used for the display portion 7103. Here, a structure in which the housing 7101 is supported by a stand 7105 is shown.

The television device 7100 can be operated with an operation switch included in the housing 7101 or a separate remote controller 7110. Channels and volume can be operated with an operation key 7109 provided in the remote controller 7110, and an image displayed on the display portion 7103 can be operated. The remote controller 7110 may be provided with a display portion 7107 for displaying information output from the remote controller 7110.

Note that the television device 7100 is provided with a receiver, a modem, and the like. General TV broadcasts can be received by a receiver, and connected to a wired or wireless communication network via a modem, so that it can be unidirectional (sender to receiver) or bidirectional (sender and receiver). It is also possible to perform information communication between each other or between recipients).

FIG. 4B illustrates a computer, which includes a main body 7201, a housing 7202, a display portion 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, and the like. Note that the computer can be manufactured using the light-emitting device which is one embodiment of the present invention for the display portion 7203. The display unit 7203 may be a touch panel (input / output device) equipped with a touch sensor (input device).

FIG. 4C illustrates a smart watch, which includes a housing 7302, a display portion 7304, operation buttons 7311 and 7312, a connection terminal 7313, a band 7321, a clasp 7322, and the like.

A display portion 7304 mounted on a housing 7302 serving also as a bezel portion has a non-rectangular display region. The display portion 7304 can display an icon 7305 representing time, other icons 7306, and the like. The display unit 7304 may be a touch panel (input / output device) equipped with a touch sensor (input device).

Note that the smart watch illustrated in FIG. 4C can have a variety of functions. For example, a function for displaying various information (still images, moving images, text images, etc.) on the display unit, a touch panel function, a function for displaying a calendar, date or time, a function for controlling processing by various software (programs), Wireless communication function, function for connecting to various computer networks using the wireless communication function, function for transmitting or receiving various data using the wireless communication function, and reading and displaying programs or data recorded on the recording medium It can have a function of displaying on the section.

In addition, a speaker, a sensor (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current are included in the housing 7302. , Voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared measurement function), microphone, and the like. Note that the smart watch can be manufactured using the light-emitting device for the display portion 7304.

FIG. 4D illustrates an example of a mobile phone (including a smartphone). A cellular phone 7400 is provided with a display portion 7402, a microphone 7406, a speaker 7405, a camera 7407, an external connection portion 7404, an operation button 7403, and the like in a housing 7401. In the case where a light-emitting element is manufactured by forming the light-emitting element according to one embodiment of the present invention over a flexible substrate, the light-emitting element can be applied to the display portion 7402 having a curved surface as illustrated in FIG. Is possible.

Information can be input to the cellular phone 7400 illustrated in FIG. 4D by touching the display portion 7402 with a finger or the like. In addition, operations such as making a call or creating a mail can be performed by touching the display portion 7402 with a finger or the like.

There are mainly three screen modes of the display portion 7402. The first mode is a display mode mainly for displaying an image. The first is a display mode mainly for displaying images, and the second is an input mode mainly for inputting information such as characters. The third is a display + input mode in which the display mode and the input mode are mixed.

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

In addition, by providing a detection device such as a gyro sensor or an acceleration sensor inside the mobile phone 7400, the orientation (portrait or horizontal) of the mobile phone 7400 is determined, and the screen display of the display portion 7402 is automatically switched. Can be.

The screen mode is switched by touching the display portion 7402 or operating the operation button 7403 of the housing 7401. Further, switching can be performed depending on the type of image displayed on the display portion 7402. For example, if the image signal to be displayed on the display unit is moving image data, the display mode is switched, and if the image signal is text data, the mode is switched to the input mode.

Further, in the input mode, when a signal detected by the optical sensor of the display unit 7402 is detected and there is no input by a touch operation of the display unit 7402 for a certain period, the screen mode is switched from the input mode to the display mode. You may control.

The display portion 7402 can function as an image sensor. For example, personal authentication can be performed by touching the display portion 7402 with a palm or a finger and capturing an image of a palm print, a fingerprint, or the like. In addition, if a backlight that emits near-infrared light or a sensing light source that emits near-infrared light is used for the display portion, finger veins, palm veins, and the like can be imaged.

Furthermore, as another configuration of the cellular phone (including a smartphone), the present invention can be applied to a cellular phone having a structure as illustrated in FIG. 4 (D′-1) or FIG. 4 (D′-2).

Note that in the case of the structure shown in FIG. 4D′-1 or FIG. 4D′-2, character information, image information, or the like is sent to the first of the housings 7500 (1) and 7500 (2). In addition to the surfaces 7501 (1) and 7501 (2), the images can be displayed on the second surfaces 7502 (1) and 7502 (2). By having such a structure, the user can easily use the character information and image information displayed on the second surface 7502 (1), 7502 (2), etc. while the mobile phone is stored in the breast pocket. Can be confirmed.

5A to 5C show a foldable portable information terminal 9310. FIG. FIG. 5A illustrates the portable information terminal 9310 in a developed state. FIG. 5B illustrates the portable information terminal 9310 in a state in which the expanded state or the folded state is changed from one to the other. FIG. 5C illustrates the portable information terminal 9310 in a folded state. The portable information terminal 9310 is excellent in portability in the folded state and excellent in display listability due to a seamless wide display area in the expanded state.

The display portion 9311 is supported by three housings 9315 connected by a hinge 9313. Note that the display unit 9311 may be a touch panel (input / output device) equipped with a touch sensor (input device). In addition, the display portion 9311 can be reversibly deformed from the expanded state to the folded state by bending the two housings 9315 via the hinge 9313. The light-emitting device of one embodiment of the present invention can be used for the display portion 9311. A display region 9312 in the display portion 9311 is a display region located on a side surface of the portable information terminal 9310 in a folded state. In the display area 9312, information icons, frequently used applications, program shortcuts, and the like can be displayed, so that information can be confirmed and applications can be activated smoothly.

As described above, an electronic device can be obtained by using the light-emitting device which is one embodiment of the present invention. Note that applicable electronic devices are not limited to those described in this embodiment, and can be applied to electronic devices in various fields.

Note that the structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 6)
In this embodiment, a structure of a lighting device manufactured using the light-emitting element which is one embodiment of the present invention will be described with reference to FIGS.

FIGS. 6A, 6B, 6C, 6D, and 6E each show an example of a cross-sectional view of a lighting device. 6A and 6B are bottom emission type lighting devices that extract light to the substrate side, and FIGS. 6C and 6D are top emission type lighting devices that extract light to the sealing substrate side. It is a lighting device.

A lighting device 4000 illustrated in FIG. 6A includes a light-emitting element 4002 over a substrate 4001. In addition, a substrate 4003 having unevenness is provided outside the substrate 4001. The light-emitting element 4002 includes a first electrode 4004, an EL layer 4005, and a second electrode 4006.

The first electrode 4004 is electrically connected to the electrode 4007, and the second electrode 4006 is electrically connected to the electrode 4008. Further, an auxiliary wiring 4009 that is electrically connected to the first electrode 4004 may be provided. Note that an insulating layer 4010 is formed over the auxiliary wiring 4009.

In addition, the substrate 4001 and the sealing substrate 4011 are bonded with a sealant 4012. In addition, a desiccant 4013 is preferably provided between the sealing substrate 4011 and the light-emitting element 4002. Note that the substrate 4003 has unevenness as shown in FIG. 6A; thus, extraction efficiency of light generated in the light-emitting element 4002 can be improved.

Further, instead of the substrate 4003, a diffusion plate 4015 may be provided outside the substrate 4001 as in the lighting device 4100 in FIG.

A lighting device 4200 in FIG. 6C includes a light-emitting element 4202 over a substrate 4201. The light-emitting element 4202 includes a first electrode 4204, an EL layer 4205, and a second electrode 4206.

The first electrode 4204 is electrically connected to the electrode 4207, and the second electrode 4206 is electrically connected to the electrode 4208. Further, an auxiliary wiring 4209 that is electrically connected to the second electrode 4206 may be provided. Further, an insulating layer 4210 may be provided below the auxiliary wiring 4209.

The substrate 4201 and the uneven sealing substrate 4211 are bonded with a sealant 4212. Further, a barrier film 4213 and a planarization film 4214 may be provided between the sealing substrate 4211 and the light-emitting element 4202. Note that the sealing substrate 4211 has unevenness as illustrated in FIG. 6C, so that extraction efficiency of light generated in the light-emitting element 4202 can be improved.

Further, instead of the sealing substrate 4211, a diffusion plate 4215 may be provided over the light-emitting element 4202 as in the lighting device 4300 in FIG.

Note that the organometallic complex which is one embodiment of the present invention can be applied to the EL layers 4005 and 4205 described in this embodiment. In this case, a lighting device with low power consumption can be provided.

Note that the structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 7)
In this embodiment, an example of a lighting device to which the light-emitting device described in Embodiment 4 is applied is described with reference to FIGS.

FIG. 7 illustrates an example in which the light-emitting device is used as an indoor lighting device 8001. Note that since the light-emitting device can have a large area, a large-area lighting device can also be formed. In addition, by using a housing having a curved surface, the lighting device 8002 in which the light emitting region has a curved surface can be formed. A light-emitting element included in the light-emitting device described in this embodiment has a thin film shape, and the degree of freedom in designing a housing is high. Therefore, it is possible to form a lighting device with various designs. Further, a large lighting device 8003 may be provided on the wall surface of the room.

Further, by using the light-emitting device on the surface of the table, the lighting device 8004 having a function as a table can be obtained. Note that a lighting device having a function as furniture can be obtained by using a light-emitting device for part of other furniture.

As described above, various lighting devices to which the light-emitting device is applied can be obtained. Note that these lighting devices are included in one embodiment of the present invention.

The structure described in this embodiment can be combined as appropriate with any of the structures described in the other embodiments.

(Embodiment 8)
In this embodiment, a touch panel including the light-emitting element of one embodiment of the present invention or the light-emitting device of one embodiment of the present invention will be described with reference to FIGS.

8A and 8B are perspective views of the touch panel 2000. FIG. 8A and 8B, typical components of the touch panel 2000 are shown for clarity.

The touch panel 2000 includes a display portion 2501 and a touch sensor 2595 (see FIG. 8B). The touch panel 2000 includes a substrate 2510, a substrate 2570, and a substrate 2590. Note that the substrate 2510, the substrate 2570, and the substrate 2590 are all flexible.

The display portion 2501 includes a plurality of pixels and a plurality of wirings 2511 that can supply signals to the pixels over the substrate 2510. The plurality of wirings 2511 are routed to the outer periphery of the substrate 2510, and a part of them constitutes a terminal 2519. A terminal 2519 is electrically connected to the FPC 2509 (1).

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 routed around the outer periphery of the substrate 2590, and part of them constitutes a terminal 2599. The terminal 2599 is electrically connected to the FPC 2509 (2). Note that in FIG. 8B, for clarity, electrodes, wirings, and the like of the touch sensor 2595 provided on the back surface side of the substrate 2590 (the surface side facing the substrate 2590) are shown by solid lines.

As the touch sensor 2595, for example, a capacitive touch sensor can be used. Examples of the electrostatic capacity method include a surface electrostatic capacity method and a projection electrostatic capacity method.

As the projected capacitance method, there are mainly a self-capacitance method and a mutual capacitance method due to a difference in driving method. The mutual capacitance method is preferable because simultaneous multipoint detection is possible.

First, the case of using a projected capacitive touch sensor will be described with reference to FIG. Note that in the case of the projected capacitance method, various sensors that can detect the proximity or contact of a detection target such as a finger can be applied.

The projected capacitive touch sensor 2595 includes an electrode 2591 and an electrode 2592. The electrode 2591 and the electrode 2592 are electrically connected to different wirings of the plurality of wirings 2598. 8A and 8B, the electrode 2592 has a shape in which a plurality of quadrilaterals repeatedly arranged in one direction are connected in one direction by wiring 2594 at corners. Similarly, the electrode 2591 has a shape in which a plurality of quadrilaterals are connected at corners, but the connection direction is a direction that intersects the direction in which the electrode 2592 is connected. Note that the direction in which the electrode 2591 is connected and the direction in which the electrode 2592 is connected do not necessarily have to be orthogonal to each other, and may be arranged to form an angle greater than 0 degree and less than 90 degrees. .

Note that a shape where the area of the intersection of the wiring 2594 and the electrode 2592 is as small as possible is preferable. Thereby, the area of the area | region in which the electrode is not provided can be reduced, and the dispersion | variation in the transmittance | permeability can be reduced. As a result, variation in luminance of light transmitted through the touch sensor 2595 can be reduced.

Note that the shapes of the electrode 2591 and the electrode 2592 are not limited thereto, and various shapes can be employed. For example, a plurality of electrodes 2591 may be arranged so as not to generate a gap as much as possible, and a plurality of electrodes 2592 may be provided with an insulating layer interposed therebetween. At this time, it is preferable to provide a dummy electrode electrically insulated from two adjacent electrodes 2592 because the area of regions having different transmittances can be reduced.

Next, details of the touch panel 2000 will be described with reference to FIG. FIG. 9 corresponds to a cross-sectional view taken along alternate long and short dash line X1-X2 in FIG.

The touch sensor 2595 includes an electrode 2591 and an electrode 2592 arranged in a staggered pattern on the substrate 2590, an insulating layer 2593 covering the electrode 2591 and the electrode 2592, and a wiring 2594 that electrically connects the adjacent electrodes 2591. Have.

Further, an adhesive layer 2597 is provided below the wiring 2594. The adhesive layer 2597 attaches the substrate 2590 to the substrate 2570 so that the touch sensor 2595 overlaps the display portion 2501.

The electrodes 2591 and 2592 are formed using a light-transmitting conductive material. As the light-transmitting conductive material, a conductive oxide such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zinc oxide to which gallium is added can be used. Note that a film containing graphene can also be used. The film containing graphene can be formed, for example, by reducing a film containing graphene oxide formed in a film shape. Examples of the reduction method include a method of applying heat.

For example, after forming a light-transmitting conductive material over the substrate 2590 by a sputtering method, unnecessary portions are removed by various patterning techniques such as a photolithography method, so that the electrode 2591 and the electrode 2592 are formed. be able to.

As a material used for the insulating layer 2593, for example, an inorganic insulating material such as silicon oxide, silicon oxynitride, or aluminum oxide can be used in addition to a resin such as acrylic or epoxy, or a resin having a siloxane bond.

Further, by forming a wiring 2594 in an opening provided in the insulating layer 2593, adjacent electrodes 2591 are electrically connected. Since the light-transmitting conductive material can increase the aperture ratio of the touch panel, it can be preferably used for the wiring 2594. A material having higher conductivity than the electrodes 2591 and 2592 can be preferably used for the wiring 2594 because electric resistance can be reduced.

The pair of electrodes 2591 are electrically connected by a wiring 2594. An electrode 2592 is provided between the pair of electrodes 2591.

The wiring 2598 is electrically connected to the electrode 2591 or the electrode 2592. Note that part of the wiring 2598 functions as a terminal. For the wiring 2598, for example, a metal material such as aluminum, gold, platinum, silver, nickel, titanium, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or an alloy material containing the metal material is used. it can.

In addition, the wiring 2598 and the FPC 2509 (2) are electrically connected to each other through a terminal 2599. Note that various anisotropic conductive films (ACF: Anisotropic Conductive Film), anisotropic conductive pastes (ACP: Anisotropic Conductive Paste), or the like can be used for the terminal 2599.

The adhesive layer 2597 has a light-transmitting property. For example, a thermosetting resin or an ultraviolet curable resin can be used, and specifically, an acrylic resin, a urethane resin, an epoxy resin, or a siloxane resin can be used.

The display portion 2501 includes a plurality of pixels arranged in a matrix. The pixel includes a display element and a pixel circuit that drives the display element.

As the substrate 2510 and the substrate 2570, for example, a flexible material having a water vapor permeability of 10 ⁻⁵ g / m ² · day or less, preferably 10 ⁻⁶ g / m ² · day or less is suitably used. be able to. Alternatively, a material in which the thermal expansion coefficient of the substrate 2510 and the thermal expansion coefficient of the substrate 2570 are approximately equal is preferably used. For example, a material having a linear expansion coefficient of 1 × 10 ⁻³ / K or less, preferably 5 × 10 ⁻⁵ / K or less, more preferably 1 × 10 ⁻⁵ / K or less can be suitably used.

In addition, the sealing layer 2560 preferably has a refractive index larger than that of air. In addition, as illustrated in FIG. 9, in the case where light is extracted to the sealing layer 2560 side, the sealing layer 2560 can also serve as an optical bonding layer.

In addition, the display portion 2501 includes a pixel 2502R. In addition, the pixel 2502R includes a light emitting module 2580R.

The pixel 2502R includes a light-emitting element 2550R and a transistor 2502t that can supply power to the light-emitting element 2550R. Note that the transistor 2502t functions as part of the pixel circuit. The light emitting module 2580R includes a light emitting element 2550R and a colored layer 2567R.

The light-emitting element 2550R includes a lower electrode, an upper electrode, and an EL layer between the lower electrode and the upper electrode.

In the case where the sealing layer 2560 is provided on the light extraction side, the sealing layer 2560 is in contact with the light-emitting element 2550R and the coloring layer 2567R.

The coloring layer 2567R is in a position overlapping with the light-emitting element 2550R. Thus, part of the light emitted from the light emitting element 2550R passes through the colored layer 2567R and is emitted to the outside of the light emitting module 2580R in the direction of the arrow shown in the drawing.

The display portion 2501 is provided with a light-blocking layer 2567BM in the direction of emitting light. The light-blocking layer 2567BM is provided so as to surround the colored layer 2567R.

In addition, the display portion 2501 includes an antireflection layer 2567p at a position overlapping with the pixel. As the antireflection layer 2567p, for example, a circularly polarizing plate can be used.

The display portion 2501 is provided with an insulating layer 2521. The insulating layer 2521 covers the transistor 2502t. Note that the insulating layer 2521 has a function of planarizing unevenness caused by the pixel circuit. Further, the insulating layer 2521 may have a function of suppressing impurity diffusion. Accordingly, a decrease in reliability of the transistor 2502t and the like due to impurity diffusion can be suppressed.

The light-emitting element 2550R is formed above the insulating layer 2521. In addition, the lower electrode included in the light-emitting element 2550R is provided with a partition wall 2528 which overlaps with an end portion of the lower electrode. Note that a spacer for controlling the distance between the substrate 2510 and the substrate 2570 may be formed over the partition wall 2528.

The scan line driver circuit 2503g (1) includes a transistor 2503t and a capacitor 2503c. Note that the driver circuit can be formed over the same substrate in the same process as the pixel circuit.

A wiring 2511 capable of supplying a signal is provided over the substrate 2510. A terminal 2519 is provided over the wiring 2511. In addition, the FPC 2509 (1) is electrically connected to the terminal 2519. In addition, the FPC 2509 (1) has a function of supplying signals such as a pixel signal and a synchronization signal. Note that a printed wiring board (PWB) may be attached to the FPC 2509 (1).

Further, transistors with various structures can be used for the display portion 2501. Note that FIG. 9A illustrates the case where a bottom-gate transistor is used. For the transistor 2502t and the transistor 2503t illustrated in FIG. 9A, a semiconductor layer including an oxide semiconductor can be used as a channel region. Alternatively, a semiconductor layer containing amorphous silicon can be used as the channel region for the transistor 2502t and the transistor 2503t. Alternatively, for the transistor 2502t and the transistor 2503t, a semiconductor layer containing polycrystalline silicon that is crystallized by treatment such as laser annealing can be used as a channel region.

FIG. 9B illustrates the structure of the display portion 2501 in the case of using a top-gate transistor.

In the case of a top-gate transistor, a semiconductor layer including a single-crystal silicon film transferred from a polycrystalline silicon or single-crystal silicon substrate is used in addition to the same structure as a semiconductor layer that can be used for a bottom-gate transistor. It may be used as a channel region.

Next, a touch panel having a configuration different from the configuration illustrated in FIG. 9 will be described with reference to FIG.

FIG. 10 is a cross-sectional view of the touch panel 2001. A touch panel 2001 shown in FIG. 10 is different from the touch panel 2000 shown in FIG. 9 in the position of the touch sensor 2595 with respect to the display unit 2501. Here, different configurations will be described in detail, and the description of the touch panel 2000 is used for a portion where a similar configuration can be used.

The coloring layer 2567R is in a position overlapping with the light-emitting element 2550R. Further, the light-emitting element 2550R illustrated in FIG. 10A emits light to the side where the transistor 2502t is provided. Thus, part of the light emitted from the light emitting element 2550R passes through the colored layer 2567R and is emitted to the outside of the light emitting module 2580R in the direction of the arrow shown in the drawing.

The display portion 2501 includes a light-blocking layer 2567BM in the direction of emitting light. The light-blocking layer 2567BM is provided so as to surround the colored layer 2567R.

The touch sensor 2595 is provided on the substrate 2510 side of the display portion 2501 (see FIG. 10A).

An adhesive layer 2597 is provided between the substrate 2510 and the substrate 2590 and attaches the display portion 2501 and the touch sensor 2595 to each other.

Further, transistors with various structures can be used for the display portion 2501. Note that FIG. 10A illustrates the case where a bottom-gate transistor is used. FIG. 10B illustrates the case where a top-gate transistor is used.

Next, an example of a touch panel driving method will be described with reference to FIG.

FIG. 11A is a block diagram illustrating a structure of a mutual capacitive touch sensor. FIG. 11A illustrates a pulse voltage output circuit 2601 and a current detection circuit 2602. In FIG. 11A, an electrode 2621 to which a pulse voltage is applied is represented by X1-X6, and an electrode 2622 for detecting a change in current is represented by Y1-Y6. FIG. 11A illustrates a capacitor 2603 formed by overlapping an electrode 2621 and an electrode 2622. Note that the functions of the electrode 2621 and the electrode 2622 may be interchanged.

The pulse voltage output circuit 2601 is a circuit for sequentially applying pulses to the wiring lines X1 to X6. When a pulse voltage is applied to the wiring of X1-X6, an electric field is generated between the electrode 2621 and the electrode 2622 forming the capacitor 2603. By utilizing the fact that the electric field generated between the electrodes causes a change in the mutual capacitance of the capacitor 2603 due to shielding or the like, it is possible to detect the proximity or contact of the detection object.

The current detection circuit 2602 is a circuit for detecting a change in current in the wirings Y1 to Y6 due to a change in mutual capacitance in the capacitor 2603. In the wiring of Y1-Y6, there is no change in the current value detected when there is no proximity or contact with the detected object, but the current value when the mutual capacitance decreases due to the proximity or contact with the detected object. Detect changes that decrease. Note that current detection may be performed using an integration circuit or the like.

Next, FIG. 11B shows a timing chart of input / output waveforms in the mutual capacitance type touch sensor shown in FIG. In FIG. 11B, the detection target is detected in each matrix in one frame period. FIG. 11B shows two cases, that is, a case where the detected object is not detected (non-touch) and a case where the detected object is detected (touch). In addition, about the wiring of Y1-Y6, the waveform made into the voltage value corresponding to the detected electric current value is shown.

A pulse voltage is sequentially applied to the X1-X6 wiring, and the waveform of the Y1-Y6 wiring changes according to the pulse voltage. When there is no proximity or contact of the detection object, the waveform of Y1-Y6 changes uniformly according to the change of the voltage of the wiring of X1-X6. On the other hand, since the current value decreases at the location where the detection object is close or in contact, the waveform of the voltage value corresponding to this also changes. In this way, by detecting the change in mutual capacitance, the proximity or contact of the detection target can be detected.

11A illustrates the structure of a passive touch sensor in which only a capacitor 2603 is provided at a wiring intersection as a touch sensor, an active touch sensor including a transistor and a capacitor may be used. FIG. 12 shows an example of one sensor circuit included in the active touch sensor.

The sensor circuit illustrated in FIG. 12 includes a capacitor 2603, a transistor 2611, a transistor 2612, and a transistor 2613.

The gate of the transistor 2613 is supplied with the signal G2, the voltage VRES is supplied to one of a source and a drain, and the other is electrically connected to one electrode of the capacitor 2603 and the gate of the transistor 2611. In the transistor 2611, one of a source and a drain is electrically connected to one of a source and a drain of the transistor 2612, and the voltage VSS is supplied to the other. In the transistor 2612, a signal G2 is supplied to a gate, and the other of the source and the drain is electrically connected to the wiring ML. The voltage VSS is applied to the other electrode of the capacitor 2603.

Next, the operation of the sensor circuit shown in FIG. 12 will be described. First, a potential for turning on the transistor 2613 is applied as the signal G2, so that a potential corresponding to the voltage VRES is applied to the node n to which the gate of the transistor 2611 is connected. Next, a potential for turning off the transistor 2613 is supplied as the signal G2, so that the potential of the node n is held. Subsequently, the potential of the node n changes from VRES as the mutual capacitance of the capacitor 2603 changes due to the proximity or contact of a detection object such as a finger.

In the reading operation, a potential for turning on the transistor 2612 is supplied to the signal G1. The current flowing through the transistor 2611, that is, the current flowing through the wiring ML is changed in accordance with the potential of the node n. By detecting this current, the proximity or contact of the detection object can be detected.

As the transistor 2611, the transistor 2612, and the transistor 2613, an oxide semiconductor layer is preferably used for a semiconductor layer in which a channel region is formed. In particular, when such a transistor is used as the transistor 2613, the potential of the node n can be held for a long time, and the frequency of the operation of supplying VRES to the node n (refresh operation) can be reduced. it can.

This embodiment can be implemented in appropriate combination with at least part of the other embodiments described in this specification.

<< Synthesis Example 1 >>
In this example, an organometallic complex which is one embodiment of the present invention represented by the structural formula (100) of Embodiment 1, bis [2- (4,5-diphenyl-2-pyrimidinyl-κN) phenyl-κC ] A synthesis method of (2,4-pentanedionato-κ ² O, O ′) iridium (III) (abbreviation: [Ir (tppm2) ₂ (acac)]) will be described. The structure of [Ir (tppm2) ₂ (acac)] is shown below.

<Step 1: Synthesis of 2,4,5-triphenylpyrimidine>
2,4,5-trichloropyrimidine 5.1 g (27.8 mmol), phenylboronic acid 10.7 g (87.4 mmol), tripotassium phosphate 18.6 g (87.4 mmol), 2-dicyclohexylphosphino-2 ′ , 6′-dimethoxybiphenyl (S-phos) 0.672 g (1.6 mmol) and toluene 100 mL were placed in a 200 mL three-necked flask, and the atmosphere in the flask was replaced with nitrogen. After deaeration, the atmosphere in the flask was replaced with nitrogen, 0.184 g (0.819 mmol) of palladium (II) acetate was added, and the mixture was stirred at 100 ° C. for 7 hours under a nitrogen stream. Water was added to the resulting reaction solution, and the aqueous layer was extracted with toluene. The organic layer and the obtained extraction solution were combined and washed with saturated brine, and anhydrous magnesium sulfate was added to the organic layer for drying. The obtained mixture was naturally filtered, and the filtrate was concentrated to obtain a solid. The solid was purified by silica column chromatography. Toluene was used as the developing solvent. The obtained fraction of the target product was concentrated to obtain 6.6 g of a white solid in a yield of 77%. It was confirmed that the white solid obtained by nuclear magnetic resonance (NMR) was 2,4,5-triphenylpyrimidine. The synthesis scheme of Step 1 is shown by the following formula (a-0).

<Step 2: Di-μ-chloro-tetrakis [2- (4,5-diphenyl-2-pyrimidinyl-κN) phenyl-κC] diiridium (III) (abbreviation: [Ir (tppm2) ₂ Cl] ₂ ) Synthesis>
2,4,5-Triphenylpyrimidine (abbreviation: Htppm2) 3.1 g (10.0 mmol) synthesized in Step 1, iridium chloride hydrate 1.43 g (4.8 mmol), 2-ethoxyethanol 30 mL, water 10 mL Was placed in a 100 mL round bottom flask, and the atmosphere in the flask was replaced with argon. This reaction vessel was reacted by irradiating with microwaves (2.45 GHz, 100 W) for 30 minutes. After the reaction, ethanol was added to the reaction solution, and ultrasonic waves were applied to pulverize the lump, followed by suction filtration to obtain 2.6 g of a yellow solid with a yield of 64%. The synthesis scheme of Step 2 is shown by the following formula (b-0).

<Step 3: Bis [2- (4,5-diphenyl-2-pyrimidinyl-κN) phenyl-κC] (2,4-pentanedionato-κ ² O, O ′) iridium (III) (abbreviation: [Ir Synthesis of (tppm2) ₂ (acac)])>
2-Ethoxyethanol 30 mL, [Ir (tppm2) ₂ Cl] ₂ 1.1 g (0.7 mmol) synthesized in Step 2, 0.651 g (6.5 mmol) acetylacetone, 0.689 g (6.5 mmol) sodium carbonate were added. The flask was placed in a 100 mL round bottom flask, and the atmosphere in the flask was replaced with argon. The reaction vessel was reacted by irradiating with microwaves (2.45 GHz 120 W) for 1.5 hours. After the reaction, the reaction mixture was concentrated to obtain a residue. Water and dichloromethane were added to the resulting residue, and the organic layer was separated. The obtained organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate. The obtained mixture was naturally filtered to obtain a filtrate. The filtrate was concentrated to give an orange solid. The obtained solid was recrystallized with a mixed solvent of ethyl acetate / ethanol to obtain 0.58 g of an orange solid in a yield of 49%. The synthesis scheme of Step 3 is shown in the following formula (c-0).

The analysis result by nuclear magnetic resonance spectroscopy ( ¹ H-NMR) of the orange solid obtained in Step 3 is shown below. A ¹ H-NMR chart is shown in FIG. From this result, it was found that the organometallic complex [Ir (tppm2) ₂ (acac)] which is one embodiment of the present invention represented by the above structural formula (100) was obtained by this synthesis example.

¹ H-NMR. δ (CDCl ₃ ): 1.81 (s, 6H), 5.29 (s, 1H), 6.52 (d, 2H), 6.85 (t, 2H), 6.90 (t, 2H) 7.26-7.30 (m, 5H), 7.34-7.47 (m, 11H), 7.69 (d, 4H), 8.11 (d, 2H), 8.67 (s). , 2H).

Moreover, when the decomposition temperature _Td of the obtained organometallic complex [Ir (tppm2) ₂ (acac)] was measured by TG-DTA, it was found that T _d = 336 ° C. and good heat resistance was exhibited. .

Next, an ultraviolet-visible absorption spectrum (hereinafter, simply referred to as “absorption spectrum”) and an emission spectrum of [Ir (tppm2) ₂ (acac)] in a dichloromethane solution were measured. For the measurement of the absorption spectrum, an ultraviolet-visible spectrophotometer (model V550 manufactured by JASCO Corporation) was used, and a dichloromethane solution (0.011 mmol / L) was placed in a quartz cell and measured at room temperature. For measurement of the emission spectrum, a defluorinated dichloromethane solution (0.011 mmol / L) was placed in a quartz cell using a fluorometer (FS920 manufactured by Hamamatsu Photonics Co., Ltd.) and measured at room temperature. The measurement results of the obtained absorption spectrum and emission spectrum are shown in FIG. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity. The absorption spectrum shown in FIG. 14 shows the result of subtracting the absorption spectrum measured by putting only dichloromethane in the quartz cell from the absorption spectrum measured by putting the dichloromethane solution (0.011 mmol / L) in the quartz cell. Yes.

As shown in FIG. 14, the organometallic complex [Ir (tppm2) ₂ (acac)] had an emission peak at 600 nm, and orange emission was observed from the dichloromethane solution.

Next, [Ir (tppm2) ₂ (acac)] obtained in this example was subjected to mass (MS) analysis by liquid chromatograph mass spectrometry (abbreviation: LC / MS analysis).

In LC / MS analysis, LC (liquid chromatography) separation was performed by Acquity UPLC manufactured by Waters, and MS analysis (mass spectrometry) was performed by Xevo G2 Tof MS manufactured by Waters. The column used for the LC separation was Acquity UPLC BEH C8 (2.1 × 100 mm 1.7 μm), and the column temperature was 40 ° C. As the mobile phase, mobile phase A was acetonitrile and mobile phase B was 0.1% formic acid aqueous solution. The sample was prepared by dissolving [Ir (tppm2) ₂ (acac)] of an arbitrary concentration in chloroform and diluting with acetonitrile, and the injection volume was 5.0 μL.

For the LC separation, a gradient method for changing the composition of the mobile phase was used. From the start of measurement to 0 to 1 minute, mobile phase A: mobile phase B = 65: 35, and then the composition was changed and the mobile phase after 10 minutes. The ratio of A to mobile phase B was set to mobile phase A: mobile phase B = 95: 5. The ratio was changed linearly.

In the MS analysis, ionization by electrospray ionization (abbreviation: ESI) was performed, the capillary voltage was 3.0 kV, the sample cone voltage was 30 V, and the detection was performed in the positive mode. The mass range to be measured was m / z = 100 to 1200.

The component of m / z = 907.26 separated and ionized under the above conditions was collided with argon gas in a collision chamber (collision cell) and dissociated into product ions. The energy (collision energy) for collision with argon was 30 eV. FIG. 15 shows the result of detection of dissociated product ions by time-of-flight (TOF) type MS.

From the results of FIG. 15, it was found that [Ir (tppm2) ₂ (acac)] detects product ions mainly in the vicinity of m / z = 807. Incidentally, the results shown in FIG. 15, the _{[Ir (tppm2) 2 (acac} )] [Ir (tppm2) 2 (acac)] Since shows the characteristic results from, contained in the mixture It can be said that this is important data for identification.

Note that product ions around m / z = 807, it _{[Ir (tppm2) 2 (acac} )] acetylacetone and protons are presumed cationic state that has left in, _{[Ir (tppm2) 2 (acac} )] , acetylacetone It is suggested that it contains.

<< Synthesis Example 2 >>
In this example, an organometallic complex which is one embodiment of the present invention represented by the structural formula (101) of Embodiment 1, bis [2- (4,5-diphenyl-2-pyrimidinyl-κN) phenyl-κC ] A synthesis method of (2,2,6,6-tetramethyl-3,5-heptanedionato-κ ² O, O ′) iridium (III) (abbreviation: [Ir (tppm2) ₂ (dpm)]) will be described. . The structure of [Ir (tppm2) ₂ (dpm)] is shown below.

<Step 1: Di-μ-chloro-tetrakis [2- (4,5-diphenyl-2-pyrimidinyl-κN) phenyl-κC] diiridium (III) (abbreviation: [Ir (tppm2) ₂ Cl] ₂ ) Synthesis>
100 mL round bottom flask of 2,4,5-triphenylpyrimidine (abbreviation: Htppm2) 2.5 g (8.1 mmol), iridium chloride hydrate 1.2 g (4.0 mmol), 2-ethoxyethanol 30 mL, water 10 mL The flask was purged with argon. The reaction vessel was reacted by irradiating with microwaves (2.45 GHz, 100 W) for 1.5 hours. After the reaction, ethanol was added to the reaction solution and ultrasonic waves were applied to pulverize the lump, followed by suction filtration to obtain 3.0 g of a yellow solid with a yield of 90%. Since Htppm2 used in this step can be synthesized by the same method as in Step 1 of Example 1, the description thereof is omitted. In addition, since the synthesis of [Ir (tppm2) ₂ Cl] ₂ described in this step can be performed by the same method as in Step 2 of Example 1, the scheme is omitted.

<Step 2; bis [2- (4,5-diphenyl-2-pyrimidinyl-κN) phenyl-κC] (2,2,6,6-tetramethyl-3,5-heptanedionato-κ ² O, O ′) Synthesis of Iridium (III) (abbreviation: [Ir (tppm2) ₂ (dpm)])>
2-Ethoxyethanol 40 mL, [Ir (tppm2) ₂ Cl] ₂ 3.0 g (1.8 mmol) synthesized in Step 1, dipivaloylmethane 3.3 g (18.0 mmol), sodium carbonate 1.9 g (18 0.0 mmol) was put into a 100 mL round bottom flask, and the inside of the flask was purged with argon. This reaction vessel was reacted by irradiating with microwaves (2.45 GHz 120 W) for 2 hours. After the reaction, the reaction mixture was concentrated to obtain a residue. Water and dichloromethane were added to the resulting residue, and the organic layer was separated. The obtained organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate. The obtained mixture was naturally filtered to obtain a filtrate. The filtrate was concentrated to give an orange solid. The obtained solid was purified by silica column chromatography. As a developing solvent, a mixed solvent of hexane: ethyl acetate = 5: 1 was used. The obtained fraction of the target product was concentrated to obtain an orange solid. The obtained solid was recrystallized with a mixed solvent of dichloromethane / ethyl acetate to obtain 0.96 g of an orange solid in a yield of 27%. 0.95 g of the obtained solid was purified by sublimation by a train sublimation method. The heating was performed at 285 ° C. for 16 hours under the conditions of a pressure of 3.6 × 10 ⁻² Pa and an argon flow rate of 0 mL / min. After sublimation purification, 0.65 g was recovered. The synthesis scheme of Step 2 is shown in the following formula (c-1).

The analysis result by nuclear magnetic resonance spectroscopy ( ¹ H-NMR) of the orange solid obtained in Step 2 is shown below. Further, the ¹ H-NMR chart is shown in FIG. From this result, it was found that the organometallic complex [Ir (tppm2) ₂ (dpm)] which is one embodiment of the present invention represented by the above structural formula (101) was obtained by this synthesis example.

¹ H-NMR. δ (CDCl ₃ ): 0.92 (s, 18H), 5.62 (s, 1H), 6.60 (d, 2H), 6.84 (t, 2H), 6.6.91 (t, 2H), 7.23-7.26 (m, 5H), 7.34-7.42 (m, 11H), 7.67 (d, 4H), 8.11 (d, 2H), 8.57. (S, 2H).

Next, an ultraviolet-visible absorption spectrum (hereinafter, simply referred to as “absorption spectrum”) and an emission spectrum of [Ir (tppm2) ₂ (dpm)] in a dichloromethane solution were measured. For the measurement of the absorption spectrum, an ultraviolet-visible spectrophotometer (V550 type manufactured by JASCO Corporation) was used, and a dichloromethane solution (0.0098 mmol / L) was put in a quartz cell and measured at room temperature. In addition, for the measurement of the emission spectrum, an absolute PL quantum yield measuring device (C11347-01 manufactured by Hamamatsu Photonics Co., Ltd.) was used, and a LABstar M13 (1250/780 manufactured by Bride Co., Ltd.) was used in a nitrogen atmosphere. A dichloromethane deoxygenated solution (0.0098 mmol / L) was put in a quartz cell, sealed, and measured at room temperature, and the measurement results of the obtained absorption spectrum and emission spectrum are shown in FIG. The vertical axis represents the absorption intensity and the emission intensity, and the absorption spectrum shown in Fig. 17 is obtained by placing only dichloromethane in the quartz cell from the absorption spectrum measured by placing the dichloromethane solution (0.0098 mmol / L) in the quartz cell. The result of subtracting the measured absorption spectrum is shown.

As shown in FIG. 17, the organometallic complex [Ir (tppm2) ₂ (dpm)] had an emission peak at 605 nm, and orange emission was observed from dichloromethane.

Next, [Ir (tppm2) ₂ (dpm)] obtained in this example was subjected to mass (MS) analysis by liquid chromatograph mass spectrometry (abbreviation: LC / MS analysis).

In LC / MS analysis, LC (liquid chromatography) separation was performed by Acquity UPLC manufactured by Waters, and MS analysis (mass spectrometry) was performed by Xevo G2 Tof MS manufactured by Waters. The column used for the LC separation was Acquity UPLC BEH C8 (2.1 × 100 mm 1.7 μm), and the column temperature was 40 ° C. As the mobile phase, mobile phase A was acetonitrile and mobile phase B was 0.1% formic acid aqueous solution. The sample was prepared by dissolving [Ir (tppm2) ₂ (dpm)] of an arbitrary concentration in chloroform and diluting with acetonitrile, and the injection volume was 5.0 μL.

For the LC separation, a gradient method for changing the composition of the mobile phase is used, and from 0 to 1 minute after the start of measurement, the mobile phase A: mobile phase B = 60: 40, then the composition is changed and the mobile phase after 4 minutes. The ratio of A to mobile phase B is mobile phase A: mobile phase B = 80: 20, and the ratio of mobile phase A to mobile phase B in 10 minutes is mobile phase A: mobile phase B = 95: 5. It was made to become. The ratio was changed linearly.

In the MS analysis, ionization by electrospray ionization (electrospray ionization (abbreviation: ESI)) was performed, the capillary voltage was 3.0 kV, the sample cone voltage was 30 V, and the detection was performed in the positive mode. The mass range to be measured was m / z = 100 to 1200.

The component of m / z = 991.35 separated and ionized under the above conditions was collided with argon gas in a collision chamber (collision cell) and dissociated into product ions. The energy (collision energy) when colliding with argon was set to 70 eV. FIG. 18 shows the result of detecting the dissociated product ions by time-of-flight (TOF) type MS.

From the results of FIG. 18, it was found that [Ir (tppm2) ₂ (dpm)] detects product ions mainly in the vicinity of m / z = 807 and m / z = 499. Incidentally, the results shown in Figure 18, the _{[Ir (tppm2) 2 (dpm} )] [Ir (tppm2) 2 (dpm)] Since shows the characteristic results from, contained in the mixture It can be said that this is important data for identification.

Note that product ions around m / z = 807 _{is, [Ir (tppm2) 2 (} dpm)] dipivaloylmethane it is estimated that the cations of the state that has left _{in, [Ir (tppm2) 2 (} dpm)] is This suggests that dipivaloylmethane is contained, and the product ion near m / z = 499 further proceeds with elimination of one molecule of 2,5-triphenylpyrimidine as a ligand. It is a suggestion.

<< Synthesis Example 3 >>
In this example, an organometallic complex which is one embodiment of the present invention represented by the structural formula (200) of Embodiment 1, tris [2- (4,5-diphenyl-2-pyrimidinyl-κN) phenyl-κC A method for synthesizing iridium (III) (abbreviation: [Ir (tppm2) ₃ ]) will be described. The structure of [Ir (tppm2) ₃ ] is shown below.

<Synthesis of Tris [2- (4,5-diphenyl-2-pyrimidinyl-κN) phenyl-κC] iridium (III) (abbreviation: [Ir (tppm2) ₃ ])>
1.5 g of di-μ-chloro-tetrakis [2- (4,5-diphenyl-2-pyrimidinyl-κN) phenyl-κC] diiridium (III) (abbreviation: [Ir (tppm2) ₂ Cl] ₂ ) .890 mmol), 2,4,5-triphenylpyrimidine 0.824 g (2.7 mmol), potassium carbonate 1.2 g (8.9 mmol) and phenol 15 g were added to a 200 mL three-necked flask, and the mixture was added at a temperature of 200 ° C. under a nitrogen stream. Heated for hours. Methanol was added to the reaction mixture and ultrasonic waves were applied to pulverize the mass, followed by suction filtration to obtain a yellow solid. The resulting solid was washed with water and then methanol. To the obtained solid, 50 mL of toluene was added, heated under reflux for 1 hour, and naturally filtered to remove insoluble matters. The obtained filtrate was concentrated to obtain a solid. The obtained solid was recrystallized with a mixed solvent of toluene / ethanol to obtain 1.4 g of a yellow solid with a yield of 68%. The synthesis scheme of this step is shown in the following formula (c-2).

The analysis result by nuclear magnetic resonance spectroscopy ( ¹ H-NMR) of the yellow solid obtained in the above step is shown below. Further, the ¹ H-NMR chart is shown in FIG. From this result, it was found that the organometallic complex [Ir (tppm2) ₃ ], which is one embodiment of the present invention represented by the above structural formula (200), was obtained in this synthesis example.

¹ H-NMR. δ (CDCl ₃ ): 6.93-7.02 (m, 15H), 7.20-7.29 (m, 15H), 7.33-7.36 (m, 3H), 7.49-7 .50 (m, 6H), 7.90 (s, 3H), 8.25-8.26 (m, 3H).

Further, when a decomposition temperature _{T d} of the obtained organometallic complex [Ir _{(tppm2) 3]} was measured by _TG-DTA, a T d = 402 ° C., it was found to exhibit excellent heat resistance.

Next, an ultraviolet-visible absorption spectrum (hereinafter, simply referred to as “absorption spectrum”) and an emission spectrum of [Ir (tppm2) ₃ ] in a dichloromethane solution were measured. For the measurement of the absorption spectrum, an ultraviolet-visible spectrophotometer (V550 type, manufactured by JASCO Corporation) was used, and a dichloromethane solution (0.010 mmol / L) was placed in a quartz cell and measured at room temperature. For measurement of the emission spectrum, a degassed dichloromethane solution (0.010 mmol / L) was placed in a quartz cell using a fluorometer (FS920 manufactured by Hamamatsu Photonics Co., Ltd.), and measurement was performed at room temperature. The measurement results of the obtained absorption spectrum and emission spectrum are shown in FIG. The horizontal axis represents wavelength, and the vertical axis represents absorption intensity and emission intensity. The absorption spectrum shown in FIG. 20 shows the result of subtracting the absorption spectrum measured by putting only dichloromethane in a quartz cell from the absorption spectrum measured by putting a dichloromethane solution (0.010 mmol / L) in the quartz cell. Yes.

As shown in FIG. 20, the organometallic complex [Ir (tppm2) ₃ ] had an emission peak at 622 nm, and orange emission was observed from dichloromethane.

[Ir (tppm2) ₃ ] obtained in this example was subjected to mass (MS) analysis by liquid chromatography mass spectrometry (abbreviation: LC / MS analysis).

In LC / MS analysis, LC (liquid chromatography) separation was performed by Acquity UPLC manufactured by Waters, and MS analysis (mass spectrometry) was performed by Xevo G2 Tof MS manufactured by Waters. The column used for the LC separation was Acquity UPLC BEH C8 (2.1 × 100 mm 1.7 μm), and the column temperature was 40 ° C. As the mobile phase, mobile phase A was acetonitrile and mobile phase B was 0.1% formic acid aqueous solution. The sample was prepared by dissolving [Ir (tppm2) ₃ ] of an arbitrary concentration in chloroform and diluting with acetonitrile, and the injection amount was 5.0 μL.

For the LC separation, a gradient method for changing the composition of the mobile phase is used, and from 0 to 1 minute after the start of measurement, the mobile phase A: mobile phase B = 80: 20, then the composition is changed and the mobile phase after 10 minutes. The ratio of A to mobile phase B was set to mobile phase A: mobile phase B = 95: 5. The ratio was changed linearly.

In the MS analysis, ionization by electrospray ionization (electrospray ionization (abbreviation: ESI)) was performed, the capillary voltage was 3.0 kV, the sample cone voltage was 30 V, and the detection was performed in the positive mode. The mass range to be measured was m / z = 100-1500.

The component of m / z = 1115.34 separated and ionized under the above conditions was collided with argon gas in the collision chamber (collision cell) and dissociated into product ions. The energy (collision energy) for collision with argon was 30 eV. FIG. 21 shows the result of detecting the dissociated product ions by time-of-flight (TOF) type MS.

From the results of FIG. 21, it is found that the product ions are detected mainly in the vicinity of m / z = 807 and in the vicinity of m / z = 309 for [Ir (tppm2) ₃ ], which is one embodiment of the present invention. all right. Incidentally, the results shown in FIG. 21, in identifying [Ir _{(tppm2) 3]} Since shows the characteristic results from a, contained in the mixture [Ir _{(tppm2) 3]} Abbreviation) It can be said that this is important data.

The product ion in the vicinity of m / z = 807 is presumed to be a cation in a state in which the ligand Htppm2 in [Ir (tppm2) ₃ ] is detached, and is one of the characteristics of [Ir (tppm2) ₃ ]. The product ion near m / z = 309 is presumed to be a cation in which a proton is added to the ligand Htppm2, and is one of the characteristics of [Ir (tppm2) ₃ ].

In this example, a light-emitting element 1 using the organometallic complex [Ir (tppm2) ₂ (acac)] (structural formula (100)) which is one embodiment of the present invention for a light-emitting layer was manufactured, and an emission spectrum was measured. went. Note that fabrication of the light-emitting element 1 will be described with reference to FIGS. In addition, chemical formulas of materials used in this example are shown below.

<< Production of Light-Emitting Element 1 >>
First, indium tin oxide containing silicon oxide (ITSO) was formed over a glass substrate 900 by a sputtering method, so that a first electrode 901 functioning as an anode was formed. The film thickness was 110 nm and the electrode area was 2 mm × 2 mm.

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

Thereafter, the substrate is introduced into a vacuum vapor deposition apparatus whose internal pressure is reduced to about 10 ⁻⁴ Pa, vacuum baking is performed at 170 ° C. for 30 minutes in a heating chamber in the vacuum vapor deposition apparatus, and then the substrate 900 is formed for about 30 minutes. Allowed to cool.

Next, the substrate 900 was fixed to a holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode 901 was formed faced down. In this embodiment, the case where the hole injection layer 911, the hole transport layer 912, the light-emitting layer 913, the electron transport layer 914, and the electron injection layer 915 that form the EL layer 902 are sequentially formed by vacuum deposition will be described. .

After depressurizing the inside of the vacuum apparatus to 10 ⁻⁴ Pa, 1,3,5-tri (dibenzothiophen-4-yl) benzene (abbreviation: DBT3P-II) and molybdenum oxide, DBT3P-II: molybdenum oxide = 4 : A hole injection layer 911 was formed over the first electrode 901 by co-evaporation so as to be 2 (mass ratio). The film thickness was 20 nm. Note that co-evaporation is an evaporation method in which a plurality of different substances are simultaneously evaporated from different evaporation sources.

Next, 4-phenyl-4 ′-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: BPAFLP) was deposited to a thickness of 20 nm, whereby the hole transport layer 912 was formed.

Next, a light-emitting layer 913 was formed over the hole transport layer 912. 2- [3 ′-(Dibenzothiophen-4-yl) biphenyl-3-yl] dibenzo [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-fluoren-2-amine (abbreviation: PCBBiF), [Ir (tppm2) ₂ (acac)] Was co-evaporated so that 2mDBTBPDBq-II: PCBBiF: [Ir (tppm2) ₂ (acac)] = 0.8: 0.2: 0.01 (mass ratio). The film thickness was 40 nm.

Next, 2 mDBTBPDBq-II was deposited to a thickness of 20 nm on the light-emitting layer 913, and then bathophenanthroline (abbreviation: Bphen) was deposited to a thickness of 10 nm, whereby the electron transport layer 914 was formed. Further, an electron injection layer 915 was formed on the electron transport layer 914 by depositing 1 nm of lithium fluoride.

Finally, aluminum was deposited on the electron injection layer 915 so as to have a thickness of 200 nm, and a second electrode 903 serving as a cathode was formed, whereby the light-emitting element 1 was obtained. Note that, in the above-described vapor deposition process, the vapor deposition was all performed by a resistance heating method.

Table 1 shows an element structure of the light-emitting element 1 obtained as described above.

The produced light-emitting element 1 was sealed in a glove box in a nitrogen atmosphere so as not to be exposed to the atmosphere (a sealing material was applied around the element, UV treatment was performed at the time of sealing, and heat treatment was performed at 80 ° C. for 1 hour. ).

<< Operating Characteristics of Light-Emitting Element 1 >>
The operating characteristics of the manufactured light-emitting element 1 were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

23 shows current density-luminance characteristics of the light-emitting element 1, FIG. 24 shows voltage-luminance characteristics of the light-emitting element 1, FIG. 25 shows luminance-current efficiency characteristics of the light-emitting element 1, and FIG. 26 shows voltage-current characteristics of the light-emitting element 1. Each is shown.

From these results, it was found that the light-emitting element 1 which is one embodiment of the present invention is a highly efficient element. In addition, Table 2 below shows main initial characteristic values of the light-emitting element 1 around 1000 cd / m ² .

From the above results, it can be seen that the light-emitting element 1 manufactured in this example has high luminance and good current efficiency. Furthermore, regarding color purity, it turns out that yellow light emission with sufficient purity is shown.

In addition, FIG. 27 shows an emission spectrum when current is passed through the light-emitting element 1 at a current density of 25 mA / cm ² . As shown in FIG. 27, the emission spectrum of the light-emitting element 1 has a peak around 566 nm and is derived from light emission of the organometallic complex [Ir (tppm2) ₂ (acac)] which is one embodiment of the present invention. It is suggested.

In this example, a light-emitting element 2 using the organometallic complex [Ir (tppm2) ₂ (dpm)] (structural formula (101)) which is one embodiment of the present invention for a light-emitting layer was manufactured, and an emission spectrum was measured. went. Note that the fabrication of the light-emitting element 2 is the same as that in Example 4, and therefore will be omitted. In addition to the materials used in Example 4, the chemical formulas of the materials used in this example are shown below.

<< Production of Light-Emitting Element 2 >>
Table 2 shows an element structure of the light-emitting element 2 manufactured in this example.

The produced light-emitting element 2 was sealed in a glove box in a nitrogen atmosphere so as not to be exposed to the atmosphere (a sealing material was applied around the element, UV treatment was performed at the time of sealing, and heat treatment was performed at 80 ° C. for 1 hour. ).

<< Operation characteristics of light-emitting element 2 >>
The operating characteristics of the manufactured light-emitting element 2 were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

28 shows current density-luminance characteristics of the light-emitting element 2, FIG. 29 shows voltage-luminance characteristics of the light-emitting element 2, FIG. 30 shows luminance-current efficiency characteristics of the light-emitting element 2, and FIG. 31 shows voltage-current characteristics of the light-emitting element 2. Each is shown.

From these results, it was found that the light-emitting element 2 which is one embodiment of the present invention is a highly efficient element. In addition, Table 4 below shows main initial characteristic values of the light-emitting element ² around 1000 cd / m ² .

From the above results, it can be seen that the light-emitting element 2 manufactured in this example has high luminance and good current efficiency. Furthermore, regarding color purity, it turns out that yellow light emission with sufficient purity is shown.

Further, FIG. 32 shows an emission spectrum obtained when a current is passed through the light-emitting element 2 at a current density of 25 mA / cm ² . As shown in FIG. 32, the emission spectrum of the light-emitting element 2 has a peak around 566 nm and is derived from light emission of the organometallic complex [Ir (tppm2) ₂ (acac)] which is one embodiment of the present invention. It is suggested.

In this example, a light-emitting element 3 using the organometallic complex [Ir (tppm2) ₃ ] (structural formula (200)) which is one embodiment of the present invention for a light-emitting layer was manufactured, and an emission spectrum was measured. Note that the fabrication of the light-emitting element 3 is the same as in Example 4 and Example 5, and thus will be omitted. In addition to the materials used in Examples 4 and 5, the chemical formulas of the materials used in this example are shown below.

<< Production of Light-Emitting Element 3 >>
Table 5 shows an element structure of the light-emitting element 3 manufactured in this example.

The produced light-emitting element 3 was sealed in a glove box in a nitrogen atmosphere so as not to be exposed to the atmosphere (a sealing material was applied around the element, UV treatment was performed at the time of sealing, and heat treatment was performed at 80 ° C. for 1 hour. ).

<< Operation characteristics of light-emitting element 3 >>
The operating characteristics of the manufactured light-emitting element 3 were measured. The measurement was performed at room temperature (atmosphere kept at 25 ° C.).

34 shows the current density-luminance characteristics of the light-emitting element 3, FIG. 35 shows the voltage-luminance characteristics of the light-emitting element 3, FIG. 36 shows the luminance-current efficiency characteristics of the light-emitting element 3, and FIG. 37 shows the voltage-current characteristics of the light-emitting element 3. Each is shown.

From these results, it was found that the light-emitting element 3 which is one embodiment of the present invention is a highly efficient element. In addition, Table 6 below shows main initial characteristic values of the light-emitting element 3 around 1000 cd / m ² .

From the above results, it can be seen that the light-emitting element 3 manufactured in this example has high luminance and good current efficiency. Furthermore, regarding color purity, it turns out that yellow light emission with sufficient purity is shown.

Further, FIG. 38 shows an emission spectrum obtained when a current is passed through the light-emitting element 3 at a current density of 25 mA / cm ² . As shown in FIG. 38, the light-emitting spectrum of the light-emitting element 3 has a peak around 569 nm, suggesting that the light-emitting element 3 is derived from light emission of the organometallic complex [Ir (tppm2) ₃ ] which is one embodiment of the present invention. Is done.

101 1st electrode 102 EL layer 103 2nd electrode 111 Hole injection layer 112 Hole transport layer 113 Light emitting layer 114 Electron transport layer 115 Electron injection layer 201 1st electrode 202 (1) 1st EL layer 202 ( 2) Second EL layer 202 (n-1) (n-1) EL layer 202 (n) (n) 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) charge generation layer 205 (n-1) (n-1) charge generation layer 301 Element substrate 302 Pixel portion 303 Drive circuit section (source line drive circuit)
304a, 304b Drive circuit section (gate line drive circuit)
305 Sealing material 306 Sealing substrate 307 Wiring 308 FPC (flexible printed circuit)
309 FET
310 FET
311 Switching FET
312 Current control FET
313 First electrode (anode)
314 Insulator 315 EL layer 316 Second electrode (cathode)
317 Light-emitting element 318 Space 351 Substrate 352 First electrode 353 Second electrode 354 EL layer 355 Insulating film 356 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 7100 Television apparatus 7101 Case 7103 Display unit 7105 Stand 7107 Display unit 7109 Operation key 7110 Remote control device 7201 Main body 7202 Case 7203 Display unit 7204 Keyboard 7205 External connection port 7206 Pointing device 7302 Case 7304 Display portion 7305 Time icon 7306 Other icons 7311 Operation button 7312 Operation button 7313 Connection terminal 7321 Band 7322 Clasp 7400 Mobile phone 7401 Body 7402 Display portion 7403 Operation button 7404 External connection portion 7405 Speaker 7406 Microphone 7407 Camera 7500 (1), 7500 (2) Cases 7501 (1), 7501 (2) First surface 7502 (1), 7502 (2) Second surface 8001 Lighting device 8002 Lighting device 8003 Lighting device 8004 Lighting device 9310 Portable information terminal 9311 Display unit 9312 Display area 9313 Hinge 9315 Case

Claims (5)

An organometallic complex represented by the formula (G2).

(In the formula (G2), R ^{1 to} R ¹² and R ¹⁴ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. R ¹³ and R ¹⁵ are each independently And M represents iridium, L represents a monoanionic bidentate chelate ligand having a β-diketone structure, m represents 3 and n represents 2. In claim 1,
The monoanionic bidentate chelate ligand having a β-diketone structure is an organometallic complex that is a ligand represented by the following formula (L1).

(However, in formula (L1), R ^{71 to} R ⁷³ each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms.) An organometallic complex represented by the formula (G4).

(In the formula (G4), R ^{1 to} R ¹² and R ¹⁴ each independently represent hydrogen or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms. R ¹³ and R ¹⁵ are each independently Represents hydrogen.) An organometallic complex represented by any one of formulas (100), (101), and (200).


Emitting device having an organic metal complex according to any one of claims 1 to 4.