WO2018189623A1 - Complexe organométallique, élément électroluminescent, dispositif électroluminescent, dispositif électronique et dispositif d'éclairage - Google Patents

Complexe organométallique, élément électroluminescent, dispositif électroluminescent, dispositif électronique et dispositif d'éclairage Download PDF

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WO2018189623A1
WO2018189623A1 PCT/IB2018/052309 IB2018052309W WO2018189623A1 WO 2018189623 A1 WO2018189623 A1 WO 2018189623A1 IB 2018052309 W IB2018052309 W IB 2018052309W WO 2018189623 A1 WO2018189623 A1 WO 2018189623A1
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light
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layer
phenyl
emitting element
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English (en)
Japanese (ja)
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山口知也
吉住英子
渡部剛吉
渡部智美
瀬尾哲史
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株式会社半導体エネルギー研究所
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
    • C07F15/00—Compounds containing elements of Groups 8, 9, 10 or 18 of the Periodic System
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/02—Details
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/02—Details
    • H05B33/06—Electrode terminals

Definitions

  • One embodiment of the present invention relates to an organometallic complex.
  • the present invention relates to an organometallic complex that can convert energy in a triplet excited state into light emission.
  • 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.
  • one embodiment of the present invention is not limited to the above technical field.
  • the technical field of one embodiment of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method.
  • one embodiment of the present invention relates to a process, a machine, a manufacture, or a composition (composition of matter).
  • a semiconductor device, a display device, a liquid crystal display device, and the like can be given as examples.
  • a light-emitting element (also referred to as an organic EL element) having an organic compound that is a light-emitting substance between a pair of electrodes has characteristics such as thin and light weight, high-speed response, and low-voltage driving. It is attracting attention as a flat panel display.
  • this light-emitting element when a voltage is applied, electrons and holes injected from the electrode are recombined, whereby the light-emitting substance enters an excited state, and emits 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.
  • fluorescent compounds fluorescent materials
  • phosphorescent material phosphorescent material
  • the theoretical limit of the internal quantum efficiency (ratio of photons generated with respect to injected carriers) in a light emitting device using each of the above light emitting substances is limited when a fluorescent material is used. Is 25%, and is 75% when a phosphorescent material is used.
  • a novel organometallic complex is provided.
  • a novel organometallic complex with high emission efficiency is provided.
  • Another embodiment of the present invention provides a novel organometallic complex that can be used for a light-emitting element.
  • Another embodiment of the present invention provides a novel organometallic complex that can be used for an EL layer of a light-emitting element.
  • a novel light-emitting element is provided.
  • a novel light-emitting device, a novel electronic device, or a novel lighting device is provided. Note that the description of these problems does not disturb the existence of other problems. Note that one embodiment of the present invention does not necessarily have to solve all of these problems. Issues other than these will be apparent from the description of the specification, drawings, claims, etc., and other issues can be extracted from the descriptions of the specification, drawings, claims, etc. It is.
  • One embodiment of the present invention is an organometallic complex including an imidazolyl skeleton containing a carbene carbon, a ligand having a triazine skeleton, and iridium.
  • Another embodiment of the present invention is an organometallic complex represented by General Formula (G1) below.
  • R 1 to R 8 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted monocyclic saturated hydrocarbon having 5 to 7 carbon atoms, substituted or It represents an unsubstituted polycyclic saturated hydrocarbon having 7 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a cyano group.
  • R 1 and R 2 may form a ring structure by a substituted or unsubstituted saturated or unsaturated condensed ring, and the ring structure is either a hydrocarbon ring compound or a heterocyclic compound .
  • Another embodiment of the present invention is an organometallic complex represented by General Formula (G2) below.
  • R 3 to R 12 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted monocyclic saturated hydrocarbon having 5 to 7 carbon atoms, substituted or It represents an unsubstituted polycyclic saturated hydrocarbon having 7 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a cyano group.
  • A, b, c, and d are either carbon or nitrogen.
  • Another embodiment of the present invention is an organometallic complex represented by General Formula (G3) below.
  • R 3 to R 8 and R 13 to R 16 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted monocyclic group having 5 to 7 carbon atoms. It represents a saturated hydrocarbon, a substituted or unsubstituted polycyclic saturated hydrocarbon having 7 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a cyano group.
  • the organometallic complex which is one embodiment of the present invention described above includes an imidazolyl skeleton containing a carbene carbon, a ligand having a triazine skeleton, and iridium.
  • the triazine skeleton has an electron donating property due to an excess of ⁇ electrons. That is, since electrons are donated from triazine to Ir, HOMO-LUMO can be lowered. Accordingly, carrier injectability can be improved, and thus, driving voltage of the light-emitting element can be reduced by using the light-emitting element.
  • the conjugation spreads by introducing triazine, the spectrum can be shifted by a long wavelength, and a desired emission color can be obtained. Note that a long wavelength shift of the spectrum is synonymous with a decrease in excitation energy, and the ratio of non-radiative deactivation is decreased due to this, so that the quantum yield can be increased.
  • Another embodiment of the present invention is an organometallic complex represented by the following structural formula (100).
  • the organometallic complex which is one embodiment of the present invention can emit phosphorescence, that is, energy in a triplet excited state can be converted into light emission, high efficiency can be obtained by application to a light-emitting element. Is possible 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.
  • Another embodiment of the present invention includes an EL layer between a pair of electrodes, the EL layer includes a light-emitting layer, and the light-emitting layer includes any of the organometallic complexes described above. It is.
  • Another embodiment of the present invention includes an EL layer between a pair of electrodes, the EL layer includes a light-emitting layer, the light-emitting layer includes a plurality of organic compounds, and the plurality of organic compounds.
  • One is a light-emitting element having any of the organometallic complexes described above.
  • 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).
  • a connector having a light emitting device such as an FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package), a module having a printed wiring board provided on the end of TCP, or a COG (Chip On Glass) on the light emitting element
  • the light emitting device also includes all modules on which IC (integrated circuit) is directly mounted by the method.
  • a novel organometallic complex can be provided.
  • a novel organometallic complex with high emission efficiency can be provided.
  • a novel organometallic complex that can be used for a light-emitting element can be provided.
  • a novel organometallic complex that can be used for an EL layer of a light-emitting element can be provided.
  • a novel light-emitting element using a novel organometallic complex can be provided.
  • a novel light-emitting 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.
  • FIG. 4A and 4B illustrate a structure of a light-emitting element.
  • FIG. 6 illustrates a light-emitting device.
  • FIG. 6 illustrates a light-emitting device.
  • 6A and 6B illustrate electronic devices.
  • 6A and 6B illustrate electronic devices.
  • 1 H-NMR chart of an organometallic complex [fac-Ir (5tznpmb) 3 ]).
  • the ultraviolet-visible absorption spectrum and emission spectrum of an organometallic complex [fac-Ir (5tznpmb) 3 ]
  • 1 H-NMR chart of an organometallic complex [mer-Ir (5tznpmb) 3 ]).
  • the ultraviolet-visible absorption spectrum and emission spectrum of an organometallic complex [mer-Ir (5tznpmb) 3 ]).
  • 3A and 3B illustrate a light-emitting element.
  • FIG. 9 shows an emission spectrum of the light-emitting element 1.
  • the organometallic complex described in this embodiment includes a ligand having an imidazolyl skeleton including a carbene carbon and a triazine skeleton, and iridium, and has a structure represented by the following general formula (G1).
  • R 1 to R 8 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted monocyclic saturated hydrocarbon having 5 to 7 carbon atoms, substituted or It represents an unsubstituted polycyclic saturated hydrocarbon having 7 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a cyano group.
  • R 1 and R 2 may form a ring structure by a substituted or unsubstituted saturated or unsaturated condensed ring, and the ring structure is either a hydrocarbon ring compound or a heterocyclic compound .
  • the organometallic complex described in this embodiment is represented by the following general formula (G2).
  • R 3 to R 12 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted monocyclic saturated hydrocarbon having 5 to 7 carbon atoms, substituted or It represents an unsubstituted polycyclic saturated hydrocarbon having 7 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a cyano group.
  • A, b, c, and d are either carbon or nitrogen.
  • the organometallic complex described in this embodiment is represented by the following general formula (G3).
  • R 3 to R 8 and R 13 to R 16 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted monocyclic group having 5 to 7 carbon atoms. It represents a saturated hydrocarbon, a substituted or unsubstituted polycyclic saturated hydrocarbon having 7 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a cyano group.
  • the substituent is a methyl group Alkyl group having 1 to 6 carbon atoms such as ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, cyclopentyl group, cyclohexyl group, C5-C7 cycloalkyl group such as cycloheptyl group, 8,9,10-trinorbornanyl group, C6-C12 such as phenyl group, naphthyl group and biphenyl group Aryl groups, and the like.
  • Alkyl group having 1 to 6 carbon atoms such as ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, cyclopentyl group,
  • alkyl group having 1 to 6 carbon atoms in the general formulas (G1) to (G3) include 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, 3-methylpentyl group, 2-methylpentyl group, 2-ethylbutyl group, 1,2 -A dimethylbutyl group, a 2, 3- dimethylbutyl group, etc. are mentioned.
  • Specific examples of the monocyclic saturated hydrocarbon having 5 to 7 carbon atoms in the general formulas (G1) to (G3) include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a 2-methylcyclohexyl group, and the like. It is done.
  • polycyclic saturated hydrocarbon having 7 to 10 carbon atoms in the general formulas (G1) to (G3) include 8,9,10-trinorbornanyl group, decahydronaphthyl group, and adamantyl group. Etc.
  • aryl group having 6 to 13 carbon atoms in the general formulas (G1) to (G3) include phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, mesityl group, o- Biphenyl group, m-biphenyl group, p-biphenyl group, 1-naphthyl group, 2-naphthyl group, fluorenyl group and the like can be mentioned.
  • the organometallic complex which is one embodiment of the present invention represented by the above general formulas (G1) to (G3) includes an imidazolyl skeleton containing a carbene carbon, a ligand having a triazine skeleton, and iridium.
  • the triazine skeleton has an electron donating property due to an excess of ⁇ electrons. That is, since electrons are donated from triazine to Ir, HOMO-LUMO can be lowered. Accordingly, carrier injectability can be improved, and thus, driving voltage of the light-emitting element can be reduced by using the light-emitting element.
  • the conjugation spreads by introducing triazine, the spectrum can be shifted by a long wavelength, and a desired emission color can be obtained.
  • a long wavelength shift of the spectrum is synonymous with a decrease in excitation energy, and the ratio of non-radiative deactivation is decreased due to this, so that the quantum yield can be increased.
  • organometallic complex represented by the structural formulas (100) to (122) is an example included in the organometallic complex that is one embodiment of the present invention, and the organometallic complex that is one embodiment of the present invention is It is not limited to this.
  • X 1 is halogen
  • R 1 to R 8 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted monocyclic saturated hydrocarbon having 5 to 7 carbon atoms.
  • R 1 and R 2 may form a ring structure by a substituted or unsubstituted saturated or unsaturated condensed ring, and the ring structure is either a hydrocarbon ring compound or a heterocyclic compound.
  • an imidazolium salt derivative represented by the general formula (G0) is obtained by coupling an imidazole derivative (a1-1) and a halogenated benzene compound (a2-1) as shown in the following synthesis scheme (A1). Thereafter, it can be obtained by reacting with a halide.
  • X 1 and X 2 are halogen
  • R 1 to R 8 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted monocyclic group having 5 to 7 carbon atoms It represents any one of the formula saturated hydrocarbon, a substituted or unsubstituted polycyclic saturated hydrocarbon having 7 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, and a cyano group.
  • R 1 and R 2 may form a ring structure by a substituted or unsubstituted saturated or unsaturated condensed ring, and the ring structure is either a hydrocarbon ring compound or a heterocyclic compound.
  • an imidazolium salt derivative represented by the general formula (G0) can be obtained by using a boronic acid (a1-2) of an imidazole derivative and a halide (a2) of a triazine. -2) and then reacting with a halide.
  • B is boronic acid, boronic acid ester or cyclic triol borate salt
  • X 1 and X 3 are halogen
  • R 1 to R 8 are each independently hydrogen, alkyl having 1 to 6 carbon atoms Group, substituted or unsubstituted monocyclic saturated hydrocarbon having 5 to 7 carbon atoms, substituted or unsubstituted polycyclic saturated hydrocarbon having 7 to 10 carbon atoms, or substituted or unsubstituted hydrocarbon having 6 to 13 carbon atoms It represents either an aryl group or a cyano group.
  • R 1 and R 2 may form a ring structure by a substituted or unsubstituted saturated or unsaturated condensed ring, and the ring structure is either a hydrocarbon ring compound or a heterocyclic compound.
  • an imidazolium salt derivative represented by the general formula (G0) can be obtained by reacting a benzene derivative-substituted diamine (a1-3) with a halide as shown in the synthesis scheme (A3). It can also be obtained.
  • A is hydrogen, an alkyl group or ammonium
  • X 1 is halogen
  • R 1 to R 8 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted carbon number Either a monocyclic saturated hydrocarbon of 5 to 7, a substituted or unsubstituted polycyclic saturated hydrocarbon having 7 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 13 carbon atoms, or a cyano group
  • R 1 and R 2 may form a ring structure by a substituted or unsubstituted saturated or unsaturated condensed ring, and the ring structure is either a hydrocarbon ring compound or a heterocyclic compound.
  • an iridium compound containing halogen such as iridium chloride hydrate, chloro (1,5-cyclooctadiene) iridium (I) dimer), silver (I) oxide, And an imidazolium salt derivative represented by the general formula (G0), and then dissolved in an alcohol solvent (glycerol, ethylene glycol, 2-methoxyethanol, 2-ethoxyethanol, etc.) or a halogen solvent (chlorobenzene) Then, the organometallic complex represented by the general formula (G1) is obtained by heating.
  • halogen such as iridium chloride hydrate, chloro (1,5-cyclooctadiene) iridium (I) dimer
  • silver (I) oxide silver oxide
  • an imidazolium salt derivative represented by the general formula (G0) an imidazolium salt derivative represented by the general formula (G0)
  • an alcohol solvent glycerol, ethylene glycol, 2-methoxyethanol, 2-ethoxyethanol
  • X 1 is halogen
  • R 1 to R 8 are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or a substituted or unsubstituted monocyclic saturated hydrocarbon having 5 to 7 carbon atoms.
  • R 1 and R 2 may form a ring structure by a substituted or unsubstituted saturated or unsaturated condensed ring, and the ring structure is either a hydrocarbon ring compound or a heterocyclic compound.
  • the present invention is not limited to this and may be synthesized by any other synthesis method.
  • 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.
  • a light-emitting element, a light-emitting device, an electronic device, or a lighting device with high emission efficiency can be realized.
  • a light-emitting element, a light-emitting device, an electronic device, or a lighting device with low power consumption can be realized.
  • Embodiment 2 In this embodiment, a light-emitting element using the organometallic complex described in Embodiment 1 will be described with reference to FIGS.
  • FIG. 1A illustrates a light-emitting element having an EL layer including a light-emitting layer between a pair of electrodes. Specifically, the EL layer 103 is sandwiched between the first electrode 101 and the second electrode 102.
  • FIG. 1B a plurality of (two layers in FIG. 1B) EL layers (103a and 103b) are provided between a pair of electrodes, and the charge generation layer 104 is provided between the EL layers.
  • 1 illustrates a light-emitting element having a stacked structure (tandem structure).
  • a light-emitting element having a tandem structure can realize a light-emitting device that can be driven at a low voltage and has low power consumption.
  • the charge generation layer 104 injects electrons into one EL layer (103a or 103b) and the other EL layer (103b or 103a). It has a function of injecting holes. Therefore, in FIG. 1B, when a voltage is applied to the first electrode 101 so that the potential is higher than that of the second electrode 102, electrons are injected from the charge generation layer 104 into the EL layer 103a, and the EL layer 103b. Holes are injected into this.
  • the charge generation layer 104 has a property of transmitting visible light in terms of light extraction efficiency (specifically, the visible light transmittance of the charge generation layer 104 is 40% or more). preferable. In addition, the charge generation layer 104 functions even when it has lower conductivity than the first electrode 101 or the second electrode 102.
  • FIG. 1C illustrates a stacked structure of the EL layer 103 of the light-emitting element which is one embodiment of the present invention.
  • the first electrode 101 functions as an anode.
  • the EL layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are sequentially stacked over the first electrode 101.
  • a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are sequentially stacked over the first electrode 101.
  • each EL layer is sequentially stacked from the anode side as described above.
  • the stacking order is reversed.
  • Each of the light-emitting layers 113 included in the EL layers (103, 103a, and 103b) includes a light-emitting substance and a plurality of substances as appropriate in combination, so that fluorescent light emission or phosphorescence light emission having a desired light emission color can be obtained. be able to.
  • the light-emitting layer 113 may have a stacked structure with different emission colors. Note that in this case, different materials may be used for the light-emitting substance and other substances used for the stacked light-emitting layers. Alternatively, different light emission colors may be obtained from the plurality of EL layers (103a and 103b) illustrated in FIG. In this case as well, the light-emitting substance and other substances used for each light-emitting layer may be different materials.
  • the first electrode 101 illustrated in FIG. 1C is used as a reflective electrode
  • the second electrode 102 is used as a semi-transmissive / semi-reflective electrode
  • a micro optical resonator is used.
  • the (microcavity) structure light emission obtained from the light-emitting layer 113 included in the EL layer 103 can resonate between both electrodes, and light emission obtained from the second electrode 102 can be strengthened.
  • the first electrode 101 of the light-emitting element is a reflective electrode having a stacked structure of a reflective conductive material and a light-transmitting conductive material (transparent conductive film)
  • a film of the transparent conductive film Optical adjustment can be performed by controlling the thickness.
  • the distance between the first electrode 101 and the second electrode 102 is near m ⁇ / 2 (where m is a natural number) with respect to the wavelength ⁇ of light obtained from the light-emitting layer 113. It is preferable to adjust as follows.
  • an optical distance from the first electrode 101 to a region (light emitting region) where the desired light of the light emitting layer 113 can be obtained an optical distance from the first electrode 101 to a region (light emitting region) where the desired light of the light emitting layer 113 can be obtained.
  • the optical distance from the second electrode 102 to the region (light emitting region) where desired light can be obtained from the light emitting layer 113 is adjusted to be close to (2m ′ + 1) ⁇ / 4 (where m ′ is a natural number). It is preferable to do this.
  • the light emitting region herein refers to a recombination region between holes and electrons in the light emitting layer 113.
  • the spectrum of specific monochromatic light obtained from the light emitting layer 113 can be narrowed, and light emission with good color purity can be obtained.
  • the optical distance between the first electrode 101 and the second electrode 102 is strictly the total thickness from the reflective region of the first electrode 101 to the reflective region of the second electrode 102. it can. However, since it is difficult to precisely determine the reflection region in the first electrode 101 or the second electrode 102, it is assumed that any position of the first electrode 101 and the second electrode 102 is the reflection region. The above-mentioned effect can be sufficiently obtained. Strictly speaking, the optical distance between the first electrode 101 and the light emitting layer from which desired light can be obtained is the optical distance between the reflective region in the first electrode 101 and the light emitting region in the light emitting layer from which desired light can be obtained. It can be said that it is a distance.
  • any position of the first electrode 101 can be set as the reflection region, the desired region. It is assumed that the above-described effect can be sufficiently obtained by assuming an arbitrary position of the light emitting layer from which light is obtained as a light emitting region.
  • the light-emitting element illustrated in FIG. 1C has a microcavity structure, light having different wavelengths (monochromatic light) can be extracted even when the light-emitting element has the same EL layer. Accordingly, there is no need for separate coloring (for example, RGB) for obtaining different emission colors. Therefore, it is easy to realize high definition. A combination with a colored layer (color filter) is also possible. Furthermore, since it is possible to increase the emission intensity of the specific wavelength in the front direction, it is possible to reduce power consumption.
  • the light-emitting element illustrated in FIG. 1E is an example of the light-emitting element having the tandem structure illustrated in FIG. 1B.
  • three EL layers (103a, 103b, and 103c) are charge generation layers. (104a, 104b). Note that the three EL layers (103a, 103b, and 103c) each have a light emitting layer (113a, 113b, and 113c), and the light emission colors of the light emitting layers can be freely combined.
  • the light-emitting layer 113a can be blue, the light-emitting layer 113b can be red, green, or yellow, and the light-emitting layer 113c can be blue, but the light-emitting layer 113a can be red and the light-emitting layer 113b can be blue, green, or yellow. In any case, the light emitting layer 113c may be red.
  • At least one of the first electrode 101 and the second electrode 102 includes a light-transmitting electrode (a transparent electrode, a semi-transmissive / semi-reflective electrode, or the like).
  • a light-transmitting electrode a transparent electrode
  • the transparent electrode has a visible light transmittance of 40% or more.
  • the visible light reflectance of the semi-transmissive / semi-reflective electrode is 20% to 80%, preferably 40% to 70%.
  • These electrodes preferably have a resistivity of 1 ⁇ 10 ⁇ 2 ⁇ cm or less.
  • the reflective electrode when one of the first electrode 101 and the second electrode 102 is a reflective electrode (reflective electrode), the reflective electrode is visible.
  • the light reflectance is 40% to 100%, preferably 70% to 100%.
  • the electrode preferably has a resistivity of 1 ⁇ 10 ⁇ 2 ⁇ cm or less.
  • the first electrode 101 is formed as a reflective electrode
  • the second electrode 102 is formed as a semi-transmissive / semi-reflective electrode. Therefore, a desired electrode material can be formed by using a single layer or a plurality of layers and forming a single layer or a stack. Note that the second electrode 102 is formed by selecting a material in the same manner as described above after the EL layer 103b is formed. In addition, a sputtering method or a vacuum evaporation method can be used for manufacturing these electrodes.
  • First electrode and second electrode> As materials for forming the first electrode 101 and the second electrode 102, the following materials can be used in appropriate combination as long as the functions of both electrodes described above can be satisfied.
  • a metal, an alloy, an electrically conductive compound, a mixture thereof, and the like can be used as appropriate.
  • an In—Sn oxide also referred to as ITO
  • an In—Si—Sn oxide also referred to as ITSO
  • an In—Zn oxide an In—W—Zn oxide
  • elements belonging to Group 1 or Group 2 of the periodic table of elements not exemplified above for example, lithium (Li), cesium (Cs), calcium (Ca), strontium (Sr)), europium (Eu), ytterbium Rare earth metals such as (Yb), alloys containing these in appropriate combinations, other graphene, and the like can be used.
  • the hole injection layer 111a and the hole transport layer 112a of the EL layer 103a are sequentially formed over the first electrode 101 by a vacuum evaporation method. Stacked. After the EL layer 103a and the charge generation layer 104 are formed, the hole injection layer 111b and the hole transport layer 112b of the EL layer 103b are sequentially stacked on the charge generation layer 104 in the same manner.
  • the hole injection layer (111, 111a, 111b) is a layer for injecting holes from the first electrode 101 serving as an anode or the charge generation layer (104) into the EL layers (103, 103a, 103b). , A layer containing a material having a high hole injection property.
  • Examples of the material having a high hole injection property include transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide.
  • phthalocyanine compounds such as phthalocyanine (abbreviation: H 2 Pc) and copper phthalocyanine (abbreviation: CuPC), 4,4′-bis [N- (4-diphenylaminophenyl) -N-phenylamino] biphenyl ( Abbreviation: DPAB), N, N′-bis ⁇ 4- [bis (3-methylphenyl) amino] phenyl ⁇ -N, N′-diphenyl- (1,1′-biphenyl) -4,4′-diamine ( An aromatic amine compound such as abbreviation (DNTPD) or a polymer such as poly (3,4-ethylenedioxythiophene) / poly (styrenesulfonic acid) (abbreviation: PEDOT / PS
  • a composite material including a hole-transporting material and an acceptor material can also be used.
  • electrons are extracted from the hole transporting material by the acceptor material, and holes are generated in the hole injection layer (111, 111a, 111b), via the hole transporting layer (112, 112a, 112b). Holes are injected into the light emitting layer (113, 113a, 113b).
  • the hole injection layer (111, 111a, 111b) may be formed as a single layer made of a composite material including a hole transporting material and an acceptor material (electron accepting material).
  • the material and the acceptor material (electron-accepting material) may be stacked in separate layers.
  • the hole transport layer (112, 112a, 112b) is configured to transfer holes injected from the first electrode 101 or the charge generation layer (104) by the hole injection layer (111, 111a, 111b). 113a, 113b).
  • the hole transport layers (112, 112a, 112b) are layers containing a hole transport material.
  • a material having a HOMO level that is the same as or close to the HOMO level of the hole injection layer (111, 111a, 111b) should be used. Is preferred.
  • an oxide of a metal belonging to Groups 4 to 8 in the periodic table can be used.
  • Specific examples include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide.
  • molybdenum oxide is especially preferable because it is stable in the air, has a low hygroscopic property, and is easy to handle.
  • organic acceptors such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives can be used.
  • F 4 -TCNQ 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane
  • chloranil 2,3,6,7,10,11 -Hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN) or the like
  • HAT-CN 2,3,6,7,10,11 -Hexacyano-1,4,5,8,9,12-hexaazatriphenylene
  • a hole transporting material used for the hole injection layer (111, 111a, 111b) and the hole transport layer (112, 112a, 112b) a substance having a hole mobility of 10 ⁇ 6 cm 2 / Vs or more is used. preferable. Note that other than these substances, any substance that has a property of transporting more holes than electrons can be used.
  • a ⁇ -electron rich heteroaromatic compound for example, a carbazole derivative or an indole derivative
  • an aromatic amine compound is preferable.
  • 4,4′-bis [N- (1-naphthyl) is preferable.
  • NPB or ⁇ -NPD N, N′-bis (3-methylphenyl) -N, N′-diphenyl- [1,1′-biphenyl] -4,4 '-Diamine (abbreviation: TPD), 4,4'-bis [N- (spiro-9,9'-bifluoren-2-yl) -N-phenylamino] biphenyl (abbreviation: BSPB), 4-phenyl-4 '-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl) triphenylamine (abbreviation: m BPAFLP), 4-phenyl-4 ′-(9-phenyl-9H-carbazol-3-yl) triphenylamine (abbreviation: PCBA1BP), 3-
  • 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.
  • the hole transporting material is not limited to the above, and various known materials may be used alone or in combination to form a hole injection layer (111, 111a, 111b) and a hole transport layer (112, 112a, 112b). ).
  • each of the hole transport layers (112, 112a, 112b) may be formed of a plurality of layers. That is, for example, a first hole transport layer and a second hole transport layer may be laminated.
  • the light-emitting layer 113a is formed over the hole-transport layer 112a of the EL layer 103a by a vacuum evaporation method.
  • the light emitting layer 113b is formed on the hole transport layer 112b of the EL layer 103b by a vacuum evaporation method.
  • the light emitting layers (113, 113a, 113b, 113c) are layers containing a light emitting substance.
  • a substance exhibiting a luminescent color such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red is appropriately used.
  • a structure exhibiting different light emission colors for example, white light emission obtained by combining light emission colors having complementary colors
  • a stacked structure in which one light emitting layer includes different light emitting substances may be used.
  • the light emitting layer may include one or more organic compounds (host material, assist material) in addition to the light emitting substance (guest material).
  • organic compounds host material, assist material
  • guest material the one or more kinds of organic compounds, one or both of a hole transporting material and an electron transporting material described in this embodiment can be used.
  • a light-emitting substance that can be used for the light-emitting layers (113, 113a, 113b, and 113c) a light-emitting substance that changes singlet excitation energy into light emission in the visible light region, or light emission that changes triplet excitation energy into light emission in the visible light region. Substances can be used.
  • Examples of other luminescent substances include the following.
  • Examples of the light-emitting substance that converts singlet excitation energy into light emission include substances that emit fluorescence (fluorescent materials).
  • fluorescent materials include fluorescence (fluorescent materials).
  • Examples include quinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.
  • a pyrene derivative is preferable because of its high emission quantum yield.
  • pyrene derivative examples include N, N′-bis (3-methylphenyl) -N, N′-bis [3- (9-phenyl-9H-fluoren-9-yl) phenyl] pyrene-1,6. -Diamine (abbreviation: 1,6 mM emFLPAPrn), N, N'-diphenyl-N, N'-bis [4- (9-phenyl-9H-fluoren-9-yl) phenyl] pyrene-1,6-diamine (abbreviation) : 1,6FLPAPrn), N, N′-bis (dibenzofuran-2-yl) -N, N′-diphenylpyrene-1,6-diamine (abbreviation: 1,6FrAPrn), N, N′-bis (dibenzothiophene) -2-yl) -N, N′-diphenylpyrene-1,6-diamine (abbreviation: 1,
  • Examples of the light-emitting substance that changes triplet excitation energy into light emission include phosphorescent substances (phosphorescent materials) and thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence. .
  • phosphorescent substances phosphorescent materials
  • TADF thermally activated delayed fluorescence
  • phosphorescent materials include organometallic complexes, metal complexes (platinum complexes), and rare earth metal complexes. Since these exhibit different emission colors (emission peaks) for each substance, they are appropriately selected and used as necessary.
  • Examples of phosphorescent materials that exhibit blue or green color and whose emission spectrum peak wavelength is 450 nm or more and 570 nm or less include the following substances.
  • Examples of the phosphorescent material which exhibits green or yellow and has an emission spectrum peak wavelength of 495 nm or more and 590 nm or less include the following substances.
  • tris (4-methyl-6-phenylpyrimidinato) iridium (III) (abbreviation: [Ir (mppm) 3 ]
  • tris (4-t-butyl-6-phenylpyrimidinato) iridium (III) (Abbreviation: [Ir (tBupppm) 3 ])
  • (acetylacetonato) bis (6-methyl-4-phenylpyrimidinato) iridium (III) abbreviation: [Ir (mppm) 2 (acac)]
  • Acetylacetonato bis (6-tert-butyl-4-phenylpyrimidinato) iridium (III) (abbreviation: [Ir (tBupppm) 2 (acac)]
  • Acetylacetonato) bis [6- (2- Norbornyl) -4-phenylpyrimidinato] iridium (III) (abbreviation: [Ir (nbpppm
  • Examples of the phosphorescent material which exhibits yellow or red and has an emission spectrum peak wavelength of 570 nm or more and 750 nm or less include the following substances.
  • the organic compound (host material, assist material) used for the light emitting layer (113, 113a, 113b, 113c) one or more kinds of substances having an energy gap larger than that of the light emitting substance (guest material) are selected. Use it.
  • the light-emitting substance is a fluorescent material
  • an organic compound having a large energy level in the ⁇ multiplied excited state and a small energy level in the triplet excited state as the host material.
  • an organic compound having a triplet excitation energy larger than the triplet excitation energy (energy difference between the ground state and the triplet excited state) of the light-emitting substance may be selected as the host material.
  • oxadiazole derivatives triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, pyrimidine derivatives, triazine derivatives, pyridine derivatives
  • aromatic amines and carbazole derivatives can be used.
  • the following hole transporting materials and electron transporting materials can be used as the host material.
  • Examples of these host materials having a high hole transporting property include N, N′-di (p-tolyl) -N, N′-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4′-bis [ N- (4-diphenylaminophenyl) -N-phenylamino] biphenyl (abbreviation: DPAB), N, N′-bis ⁇ 4- [bis (3-methylphenyl) amino] phenyl ⁇ -N, N′-diphenyl -(1,1′-biphenyl) -4,4′-diamine (abbreviation: DNTPD), 1,3,5-tris [N- (4-diphenylaminophenyl) -N-phenylamino] benzene (abbreviation: DPA3B)
  • An aromatic amine compound such as
  • PCzDPA1 3- [N- (4-diphenylaminophenyl) -N-phenylamino] -9-phenylcarbazole
  • PCzDPA2 3,6-bis [N- (4-diphenylaminophenyl) -N-phenyl Amino] -9-phenylcarbazole
  • PCzTPN2 3,6-bis [N- (4-diphenylaminophenyl) -N- (1-naphthyl) amino] -9-phenylcarbazole
  • PCzTPN2 3 -[N- (9-phenylcarbazol-3-yl) -N-phenylamino] -9-phenylcarbazole
  • PCzPCA1 3,6-bis [N- (9-phenylcarbazol-3-yl)- N-phenylamino] -9-phenylcarbazole
  • CBP 4,4′-di (N-carbazolyl) biphenyl
  • TCPB 1,3,5-tris [4- (N-carbazolyl) phenyl] benzene
  • NPB or ⁇ -NPD 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl
  • NPB or ⁇ -NPD 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl
  • NPB or ⁇ -NPD N, N ′ -Bis (3-methylphenyl) -N, N'-diphenyl- [1,1'-biphenyl] -4,4'-diamine
  • TPD 4,4 ', 4 "-tris (carbazole- 9-yl) triphenylamine
  • TCTA 4,4 ′, 4 ′′ -tris [N- (1-naphthyl) -N-phenylamino] triphenylamine
  • 1′-TNATA 4 , 4 ′, 4 ′′ -tris (N, N-diphenylamino) triphenylamine
  • PCPN 3- [4- (1-naphthyl) -phenyl] -9-phenyl-9H-carbazole
  • PCPPn 3- [4- (9-phenanthryl) -phenyl] -9-phenyl-9H-carbazole
  • PCCP 3,3′-bis (9-phenyl-9H-carbazole)
  • mCP 1,3-bis (N-carbazolyl) benzene
  • CzTP 3,6-bis ( 3,5-diphenylphenyl) -9-phenylcarbazole
  • CzTP 3,6-bis ( 3,5-diphenylphenyl) -9-phenylcarbazole
  • Examples of the host material having a high electron transporting property include tris (8-quinolinolato) aluminum (III) (abbreviation: Alq), tris (4-methyl-8-quinolinolato) aluminum (III) (abbreviation: Almq 3 ), and bis. (10-hydroxybenzo [h] quinolinato) beryllium (II) (abbreviation: BeBq 2 ), bis (2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum (III) (abbreviation: BAlq), bis ( Metal complexes having a quinoline skeleton or a benzoquinoline skeleton, such as 8-quinolinolato) zinc (II) (abbreviation: Znq).
  • bis [2- (2-benzoxazolyl) phenolato] zinc (II) (abbreviation: ZnPBO), bis [2- (2-benzothiazolyl) phenolato] zinc (II) (abbreviation: ZnBTZ), etc.
  • ZnPBO bis [2- (2-benzoxazolyl) phenolato] zinc
  • ZnBTZ bis [2- (2-benzothiazolyl) phenolato] zinc
  • a metal complex having an oxazole-based or thiazole-based ligand can also be used.
  • 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)
  • PPy poly [(9,9-dioctylfluorene-2,7-diyl) -co- (2,2′-bipyridine-6,6′-diyl)]
  • PF-BPy Molecular compounds
  • Examples of the host material include condensed polycyclic aromatic compounds such as anthracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, and dibenzo [g, p] chrysene derivatives.
  • first compound and second compound are mixed with an organometallic complex. May be used.
  • various organic compounds can be used in appropriate combination.
  • a compound that easily receives holes (hole transporting material) and a compound that easily receives electrons (electrons) A combination with a transportable material) is particularly preferred.
  • the materials described in this embodiment can be used. With this configuration, high efficiency, low voltage, and long life can be realized simultaneously.
  • TADF material is a material that can up-convert triplet excited state to singlet excited state with a little thermal energy (interverse crossing) and efficiently emits light (fluorescence) from singlet excited state. is there.
  • the energy difference between the triplet excited level and the singlet excited level is 0 eV or more and 0.2 eV or less, preferably 0 eV or more and 0.1 eV or less.
  • delayed fluorescence in the 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.
  • TADF material examples include fullerene and derivatives thereof, acridine derivatives such as proflavine, and eosin.
  • metal-containing porphyrins including magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), and the like can be given.
  • metal-containing porphyrin examples include a protoporphyrin-tin fluoride complex (abbreviation: SnF 2 (Proto IX)), a mesoporphyrin-tin fluoride complex (abbreviation: SnF 2 (Meso IX)), and hematoporphyrin-tin fluoride.
  • SnF 2 Proto IX
  • SnF 2 mesoporphyrin-tin fluoride complex
  • hematoporphyrin-tin fluoride examples include hematoporphyrin-tin fluoride.
  • SnF 2 Hemato IX
  • SnF 2 coproporphyrin tetramethyl ester-tin fluoride complex
  • SnF 2 Copro III-4Me
  • SnF 2 octaethylporphyrin-tin fluoride complex
  • SnF 2 (OEP) Etioporphyrin-tin fluoride complex
  • PtCl 2 OEP octaethylporphyrin-platinum chloride complex
  • a substance in which a ⁇ -electron rich heteroaromatic ring and a ⁇ -electron deficient heteroaromatic ring are directly bonded increases both the donor property of the ⁇ -electron rich heteroaromatic ring and the acceptor property of the ⁇ -electron deficient heteroaromatic ring. This is particularly preferable because the energy difference between the singlet excited state and the triplet excited state becomes small.
  • TADF material when using TADF material, it can also be used in combination with another organic compound.
  • the electron-transport layer 114a is formed over the light-emitting layer 113a of the EL layer 103a by a vacuum evaporation method.
  • the electron transport layer 114b is formed on the light emitting layer 113b of the EL layer 103b by a vacuum evaporation method.
  • the electron transport layers (114, 114a, 114b) are formed by allowing the electrons injected from the second electrode 102 and the charge generation layer 104 to the light emitting layers (113, 113a, 113b) by the electron injection layers (115, 115a, 115b).
  • the layer to transport is layers containing an electron transport material.
  • the electron transporting material used for the electron transporting layer (114, 114a, 114b) is preferably a substance having an electron mobility of 1 ⁇ 10 ⁇ 6 cm 2 / Vs or higher. Note that other than these substances, any substance that has a property of transporting more electrons than holes can be used.
  • electron transporting materials include metal complexes having quinoline ligand, benzoquinoline ligand, oxazole ligand, or thiazole ligand, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, etc. Is mentioned.
  • a ⁇ -electron deficient heteroaromatic compound such as a nitrogen-containing heteroaromatic compound can also be used.
  • Alq 3 tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq 3 ), bis (10-hydroxybenzo [h] quinolinato) beryllium (abbreviation: BeBq 2 ), BAlq, bis [2 -(2-hydroxyphenyl) benzoxazolate] zinc (II) (abbreviation: Zn (BOX) 2 ), bis [2- (2-hydroxyphenyl) benzothiazolate] zinc (abbreviation: Zn (BTZ) 2 ), etc.
  • 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)
  • PPy poly [(9,9-dioctylfluorene-2,7-diyl) -co- (2,2′-bipyridine-6,6′-diyl)]
  • PF-BPy Molecular compounds
  • the electron-transport layer (114, 114a, 114b) is not limited to a single layer, and may have a structure in which two or more layers made of the above substances are stacked.
  • an electron injection layer 115a is formed over the electron transport layer 114a of the EL layer 103a by a vacuum evaporation method. Thereafter, the EL layer 103a and the charge generation layer 104 are formed, and the electron transport layer 114b of the EL layer 103b is formed, and then the electron injection layer 115b is formed thereon by a vacuum deposition method.
  • the electron injection layers (115, 115a, 115b) are layers containing a substance having a high electron injection property.
  • the electron injection layer (115, 115a, 115b) includes an alkali metal such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF 2 ), lithium oxide (LiO x ), or the like. Earth metals or their compounds can be used. Alternatively, a rare earth metal compound such as erbium fluoride (ErF 3 ) can be used.
  • electride may be used for the electron injection layer (115, 115a, 115b). Examples of the electride include a substance obtained by adding a high concentration of electrons to a mixed oxide of calcium and aluminum. In addition, the substance which comprises the electron carrying layer (114, 114a, 114b) mentioned above can also be used.
  • a composite material obtained by mixing an organic compound and an electron donor (donor) may be used for the electron injection layer (115, 115a, 115b).
  • 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.
  • the organic compound is preferably a material excellent in transporting the generated electrons.
  • an electron transport material metal complex used for the electron transport layer (114, 114a, 114b) described above, for example.
  • a heteroaromatic compound may be any substance that exhibits an electron donating property to the organic compound.
  • 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.
  • an organic compound such as tetrathiafulvalene (abbreviation: TTF) can be used.
  • the optical distance between the second electrode 102 and the light-emitting layer 113b is less than ⁇ / 4 with respect to the wavelength of light exhibited by the light-emitting layer 113b. It is preferable to form such that In this case, adjustment can be performed by changing the film thickness of the electron transport layer 114b or the electron injection layer 115b.
  • the charge generation layer 104 injects electrons into the EL layer 103a and applies holes into the EL layer 103b when a voltage is applied between the first electrode (anode) 101 and the second electrode (cathode) 102.
  • the charge generation layer 104 has a function of injecting an electron donor (donor) to the electron transporting material even if the electron transporting material 104 has a structure in which an electron acceptor (acceptor) is added to the hole transporting material. It may be a configuration. Moreover, both these structures may be laminated
  • the materials described in this embodiment can be used as the hole-transporting material.
  • the electron acceptor include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F 4 -TCNQ), chloranil, and the like.
  • oxides of metals belonging to Groups 4 to 8 in the periodic table can be given. Specific examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.
  • the materials described in this embodiment can be used as the electron transporting material.
  • 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.
  • 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.
  • the EL layer 103c in FIG. 1E may have a structure similar to that of the above-described EL layers (103, 103a, and 103b).
  • the charge generation layers 104a and 104b may have the same structure as the charge generation layer 104 described above.
  • the light-emitting element described in this embodiment can be formed over various substrates.
  • substrate is not limited to a specific thing.
  • a semiconductor substrate for example, a single crystal substrate or a silicon substrate
  • an SOI substrate for example, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate having stainless steel foil, a tungsten substrate
  • Examples include 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 flexible substrates, bonded films, base films, etc. are synthetic materials such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyether sulfone (PES), acrylic, etc. Examples thereof include resin, polypropylene, polyester, polyvinyl fluoride, or polyvinyl chloride, polyamide, polyimide, aramid, epoxy, inorganic vapor deposition film, and papers.
  • a vacuum process such as an evaporation method or a solution process such as a spin coating method or an inkjet method can be used.
  • vapor deposition physical vapor deposition (PVD) such as sputtering, ion plating, ion beam vapor deposition, molecular beam vapor deposition, or vacuum vapor deposition, or chemical vapor deposition (CVD) is used. be able to.
  • PVD physical vapor deposition
  • CVD chemical vapor deposition
  • functional layers hole injection layer (111, 111a, 111b), hole transport layer (112, 112a, 112b), light-emitting layer (113, 113a, 113b, 113c), electron transport included in the EL layer of the light-emitting element.
  • a vapor deposition method vacuum vapor deposition method, etc.
  • a coating method dip coating method
  • Die coating method bar coating method
  • spin coating method spin coating method
  • spray coating method etc.
  • printing method inkjet method, screen (stencil printing) method, offset (lithographic printing) method, flexographic (letter printing) method, gravure method, microcontact And the like.
  • each functional layer (a hole injection layer (111, 111a, 111b), a hole transport layer (112, 112a, 112b) included in the EL layer (103, 103a, 103b) of the light-emitting element described in this embodiment mode.
  • the light emitting layer (113, 113a, 113b, 113c), the electron transport layer (114, 114a, 114b), the electron injection layer (115, 115a, 115b)) and the charge generation layer (104, 104a, 104b) are described above.
  • the material is not limited, and other materials can be used in combination as long as they can satisfy the function of each layer.
  • high molecular compounds oligomers, dendrimers, polymers, etc.
  • medium molecular compounds compounds in the middle region between low molecules and polymers: molecular weight 400 to 4000
  • inorganic compounds quantum dot materials, etc.
  • quantum dot material a colloidal quantum dot material, an alloy type quantum dot material, a core / shell type quantum dot material, a core type quantum dot material, or the like can be used.
  • 2A is an active matrix light-emitting device in which a transistor (FET) 202 over a first substrate 201 and light-emitting elements (203R, 203G, 203B, and 203W) are electrically connected to each other.
  • the plurality of light emitting elements (203R, 203G, 203B, 203W) have a common EL layer 204, and the optical distance between the electrodes of each light emitting element depends on the emission color of each light emitting element. It has a tuned microcavity structure.
  • the light-emitting device is a top-emission light-emitting device in which light emission obtained from the EL layer 204 is emitted through color filters (206R, 206G, and 206B) formed over the second substrate 205.
  • the first electrode 207 is formed so as to function as a reflective electrode.
  • the second electrode 208 is formed so as to function as a semi-transmissive / semi-reflective electrode. Note that an electrode material for forming the first electrode 207 and the second electrode 208 may be used as appropriate with reference to the description of the other embodiments.
  • the light emitting element 203R is a red light emitting element
  • the light emitting element 203G is a green light emitting element
  • the light emitting element 203B is a blue light emitting element
  • the light emitting element 203W is a white light emitting element, FIG.
  • the light emitting element 203R is adjusted so that the optical distance 200R is between the first electrode 207 and the second electrode 208
  • the light emitting element 203G includes the first electrode 207 and the second electrode.
  • the light emitting element 203B is adjusted so that the optical distance 200B is between the first electrode 207 and the second electrode 208.
  • optical adjustment can be performed by stacking the conductive layer 210R over the first electrode 207 in the light-emitting element 203R and stacking the conductive layer 210G in the light-emitting element 203G.
  • color filters (206R, 206G, 206B) are formed on the second substrate 205.
  • the color filter is a filter that passes a specific wavelength range of visible light and blocks the specific wavelength range. Therefore, as shown in FIG. 2A, red light emission can be obtained from the light emitting element 203R by providing the color filter 206R that allows only the red wavelength region to pass through the position overlapping the light emitting element 203R.
  • green light emission can be obtained from the light emitting element 203G.
  • the color filter 206B that allows only the blue wavelength region to pass at a position overlapping the light emitting element 203B, blue light emission can be obtained from the light emitting element 203B.
  • the light emitting element 203W can obtain white light emission without providing a color filter.
  • a black layer (black matrix) 209 may be provided at an end of one type of color filter.
  • the color filters (206R, 206G, 206B) and the black layer 209 may be covered with an overcoat layer using a transparent material.
  • FIG. 2A a light emitting device having a structure for extracting light emission to the second substrate 205 side (top emission type) is shown, but the first substrate on which the FET 202 is formed as shown in FIG.
  • a light emitting device having a structure for extracting light to the 201 side (bottom emission type) may be used.
  • the first electrode 207 is formed to function as a semi-transmissive / semi-reflective electrode
  • the second electrode 208 is formed to function as a reflective electrode.
  • the first substrate 201 is at least a light-transmitting substrate.
  • the color filters (206R ′, 206G ′, and 206B ′) may be provided on the first substrate 201 side with respect to the light emitting elements (203R, 203G, and 203B) as shown in FIG.
  • the light-emitting element is a red light-emitting element, a green light-emitting element, a blue light-emitting element, or a white light-emitting element
  • the light-emitting element which is one embodiment of the present invention is limited to the structure.
  • a structure having a yellow light emitting element or an orange light emitting element may be used.
  • a material used for EL layers (a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a charge generation layer, etc.) for manufacturing these light emitting elements, other embodiments are used. May be used as appropriate with reference to the description. In this case, it is necessary to select a color filter as appropriate in accordance with the emission color of the light emitting element.
  • a light-emitting device including a light-emitting element that exhibits a plurality of emission colors can be obtained.
  • an active matrix light-emitting device or a passive matrix light-emitting device can be manufactured.
  • an active matrix light-emitting device has a structure in which a light-emitting element and a transistor (FET) are combined. Therefore, both a passive matrix light-emitting device and an active matrix light-emitting device are included in one embodiment of the present invention.
  • FET transistor
  • the light-emitting element described in any of the other embodiments can be applied to the light-emitting device described in this embodiment.
  • an active matrix light-emitting device is described with reference to FIGS.
  • FIG. 3A is a top view illustrating the light-emitting device
  • FIG. 3B is a cross-sectional view taken along the chain line A-A ′ in FIG. 3A.
  • the active matrix light-emitting device includes a pixel portion 302, a driver circuit portion (source line driver circuit) 303, and driver circuit portions (gate line driver circuits) (304a and 304b) provided over the first substrate 301. .
  • the pixel portion 302 and the driver circuit portions (303, 304a, and 304b) are sealed between the first substrate 301 and the second substrate 306 by a sealant 305.
  • a lead wiring 307 is provided over the first substrate 301.
  • the lead wiring 307 is connected to the FPC 308 which is an external input terminal.
  • the FPC 308 transmits signals (eg, a video signal, a clock signal, a start signal, a reset signal, and the like) and a potential from the outside to the driving circuit units (303, 304a, and 304b).
  • a printed wiring board (PWB) may be attached to the FPC 308. Note that the state in which the FPC or PWB is attached is included in the light emitting device.
  • the pixel portion 302 is formed by a plurality of pixels including a FET (switching FET) 311, a FET (current control FET) 312, and a first electrode 313 electrically connected to the FET 312.
  • a FET switching FET
  • FET current control FET
  • first electrode 313 electrically connected to the FET 312. Note that the number of FETs included in each pixel is not particularly limited, and can be appropriately provided as necessary.
  • the FETs 309, 310, 311, and 312 are not particularly limited, and for example, a staggered type transistor or an inverted staggered type transistor can be applied. Further, a transistor structure such as a top gate type or a bottom gate type may be used.
  • crystallinity of the semiconductor there is no particular limitation on the crystallinity of the semiconductor that can be used for these FETs 309, 310, 311, and 312; an amorphous semiconductor, a semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, Alternatively, a semiconductor having a crystal region in part) may be used. Note that it is preferable to use a crystalline semiconductor because deterioration of transistor characteristics can be suppressed.
  • Group 14 elements for example, Group 14 elements, compound semiconductors, oxide semiconductors, organic semiconductors, and the like can be used.
  • a semiconductor containing silicon, a semiconductor containing gallium arsenide, an oxide semiconductor containing indium, or the like can be used.
  • the drive circuit unit 303 includes an FET 309 and an FET 310.
  • the FET 309 and the FET 310 may be formed of a circuit including a unipolar transistor (N-type or P-type only) or a CMOS circuit including an N-type transistor and a P-type transistor. May be.
  • a configuration in which a drive circuit is provided outside may be employed.
  • an end portion of the first electrode 313 is covered with an insulator 314.
  • the insulator 314 can be formed using an organic compound such as a negative photosensitive resin or a positive photosensitive resin (acrylic resin), or an inorganic compound such as silicon oxide, silicon oxynitride, or silicon nitride. . It is preferable that an upper end portion or a lower end portion of the insulator 314 have a curved surface having a curvature. Thereby, the coverage of the film formed on the upper layer of the insulator 314 can be improved.
  • the EL layer 315 and a second electrode 316 are stacked over the first electrode 313.
  • the EL layer 315 includes a light-emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, a charge generation layer, and the like.
  • the structures and materials described in the other embodiments can be applied to the structure of the light-emitting element 317 described in this embodiment.
  • the second electrode 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.
  • 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.
  • 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.
  • a light emitting device capable of full color display may be obtained by combining with a color filter.
  • types of color filters red (R), green (G), blue (B), cyan (C), magenta (M), yellow (Y), and the like can be used.
  • the FETs (309, 310, 311 and 312) and the light emitting element 317 over the first substrate 301 are bonded to each other by attaching the second substrate 306 and the first substrate 301 with the sealant 305. 301, the second substrate 306, and a structure provided in a space 318 surrounded by the sealant 305.
  • the space 318 may be filled with an inert gas (such as nitrogen or argon) or an organic substance (including the sealant 305).
  • an epoxy resin or glass frit can be used as the sealant 305. Note that it is preferable to use a material that does not transmit moisture and oxygen as much as possible for the sealant 305.
  • a substrate that can be used for the first substrate 301 can be used as well. Therefore, various substrates described in other embodiments can be used as appropriate.
  • a plastic substrate made of FRP (Fiber-Reinforced Plastics), PVF (polyvinyl fluoride), polyester, acrylic, or the like can be used as the substrate.
  • the first substrate 301 and the second substrate 306 are preferably glass substrates from the viewpoint of adhesiveness.
  • an active matrix light-emitting device can be obtained.
  • the FET and the light-emitting element may be directly formed over the flexible substrate, but the FET and the light-emitting element are formed over another substrate having a release layer.
  • the FET and the light-emitting element may be peeled off by a peeling layer by applying heat, force, laser irradiation, and transferred to a flexible substrate.
  • the peeling layer for example, a laminated inorganic film of a tungsten film and a silicon oxide film, an organic resin film such as polyimide, or the like can be used.
  • flexible substrates include paper substrates, cellophane substrates, aramid film substrates, polyimide film substrates, fabric substrates (natural fibers (silk, cotton, hemp), synthetic fibers ( Nylon, polyurethane, polyester) or recycled fibers (including acetate, cupra, rayon, recycled polyester), leather substrates, rubber substrates, and the like.
  • paper substrates cellophane substrates
  • aramid film substrates polyimide film substrates
  • fabric substrates natural fibers (silk, cotton, hemp), synthetic fibers ( Nylon, polyurethane, polyester) or recycled fibers (including acetate, cupra, rayon, recycled polyester), leather substrates, rubber substrates, and the like.
  • 4A to 4E includes a housing 7000, a display portion 7001, a speaker 7003, an LED lamp 7004, operation keys 7005 (including a power switch or an operation switch), a connection terminal 7006, Sensor 7007 (force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity , Including a function of measuring inclination, vibration, odor, or infrared light), microphones 7008, 7019, and the like.
  • Sensor 7007 force, displacement, position, velocity, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity , Including a function of measuring inclination, vibration, odor, or infrared light
  • microphones 7008, 7019 and the like.
  • FIG. 4A illustrates a mobile computer, which can include a switch 7009, an infrared port 7010, and the like in addition to the above objects.
  • FIG. 4B illustrates a portable image reproducing device (eg, a DVD reproducing device) provided with a recording medium, which includes a second display portion 7002, a recording medium reading portion 7011, and the like in addition to those described above. it can.
  • a portable image reproducing device eg, a DVD reproducing device
  • a recording medium which includes a second display portion 7002, a recording medium reading portion 7011, and the like in addition to those described above. it can.
  • FIG. 4C illustrates a goggle type display which can include a second display portion 7002, a support portion 7012, an earphone 7013, and the like in addition to the above components.
  • FIG. 4D illustrates a digital camera with a television receiving function, which can include an antenna 7014, a shutter button 7015, an image receiving portion 7016, and the like in addition to the above objects.
  • FIG. 4E illustrates a mobile phone (including a smartphone), which can include a display portion 7001, a microphone 7019, and the like in a housing 7000.
  • FIG. 4F illustrates a large television device (also referred to as a television or a television receiver) which can include a housing 7000, a display portion 7001, speakers 7003, and the like.
  • a configuration in which the casing 7000 is supported by a stand 7018 is shown.
  • the electronic devices illustrated in FIGS. 4A to 4F 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, etc., a function for controlling processing by various software (programs) , Wireless communication function, function to connect to various computer networks using wireless communication function, function to transmit or receive various data using wireless communication function, read program or data recorded in recording medium
  • a function of displaying on the display portion can be provided. Further, in an electronic device having a plurality of display units, one display unit mainly displays image information and another one display unit mainly displays character information, or the plurality of display units consider parallax.
  • a function of displaying a three-dimensional image, etc. by displaying the obtained image. Furthermore, in an electronic device having an image receiving unit, a function for capturing a still image, a function for capturing a moving image, a function for correcting a captured image automatically or manually, and a captured image on a recording medium (externally or incorporated in a camera) A function of saving, a function of displaying a photographed image on a display portion, and the like can be provided. Note that the functions of the electronic devices illustrated in FIGS. 4A to 4F are not limited to these, and the electronic devices can have various functions.
  • FIG. 4G illustrates a smart watch, which includes a housing 7000, a display portion 7001, operation buttons 7022 and 7023, a connection terminal 7024, a band 7025, a clasp 7026, and the like.
  • a display portion 7001 mounted on a housing 7000 that also serves as a bezel portion has a non-rectangular display region.
  • the display portion 7001 can display an icon 7027 representing time, other icons 7028, and the like.
  • the display unit 7001 may be a touch panel (input / output device) equipped with a touch sensor (input device).
  • the smart watch illustrated in FIG. 4G 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, etc., a function for controlling processing by various software (programs) , Wireless communication function, function to connect to various computer networks using wireless communication function, function to transmit or receive various data using wireless communication function, read program or data recorded in recording medium A function of displaying on the display portion can be provided.
  • a speaker In addition, a speaker, a sensor (force, displacement, position, velocity, acceleration, angular velocity, number of rotations, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current are included in the housing 7000. , Voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared measurement function), microphone, and the like.
  • the light-emitting device which is one embodiment of the present invention and the display device including the light-emitting element which is one embodiment of the present invention can be used for each display portion of the electronic device described in this embodiment and display with high color purity. Is possible.
  • FIGS. 5A to 5C a foldable portable information terminal as illustrated in FIGS. 5A to 5C can be given.
  • FIG. 5A illustrates the portable information terminal 9310 in a developed state.
  • FIG. 5B illustrates the portable information terminal 9310 in a state of changing from one of the expanded state and the folded state 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.
  • the display unit 9311 may be a touch panel (input / output device) equipped with a touch sensor (input device).
  • 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.
  • display with good color purity is possible.
  • 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.
  • FIGS. 6A and 6B illustrate an automobile to which the light-emitting device is applied. That is, the light emitting device can be provided integrally with the automobile.
  • the present invention can be applied to a light 5101 (including a rear part of a vehicle body), a wheel 5102 of a tire, a part of or the whole of a door 5103 shown in FIG.
  • the present invention can be applied to a display portion 5104, a handle 5105, a shift lever 5106, a seat seat 5107, an inner rear view mirror 5108, and the like inside the automobile shown in FIG.
  • an electronic device or a vehicle using the light-emitting device or the display device which is one embodiment of the present invention can be obtained.
  • display with good color purity is possible.
  • applicable electronic devices and automobiles are not limited to those described in this embodiment, and can be applied in any field.
  • FIGS. 7A, 7B, 7C, and 7D each show an example of a cross-sectional view of a lighting device.
  • 7A and 7B are bottom emission type lighting devices that extract light to the substrate side
  • FIGS. 7C and 7D 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. 7A includes a light-emitting element 4002 over a substrate 4001.
  • 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.
  • the substrate 4001 and the sealing substrate 4011 are bonded with a sealant 4012.
  • a desiccant 4013 is preferably provided between the sealing substrate 4011 and the light-emitting element 4002. Note that since the substrate 4003 has unevenness as illustrated in FIG. 7A, the light extraction efficiency of the light-emitting element 4002 can be improved.
  • 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. 7C 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. 7C, so that extraction efficiency of light generated in the light-emitting element 4202 can be improved.
  • a diffusion plate 4215 may be provided over the light-emitting element 4202 as in the lighting device 4300 in FIG.
  • a lighting device having desired chromaticity can be provided by using a light-emitting device which is one embodiment of the present invention or a light-emitting element which is a part thereof.
  • the ceiling light 8001 includes a direct ceiling type and a ceiling embedded type. Note that such an illumination device is configured by combining a light emitting device with a housing or a cover. In addition, it can be applied to a cord pendant type (a cord hanging type from the ceiling).
  • the foot lamp 8002 can illuminate the floor surface and enhance the safety of the foot. For example, it is effective to use it for a bedroom, a staircase or a passage. In that case, the size and shape can be appropriately changed according to the size and structure of the room.
  • a stationary illumination device configured by combining a light emitting device and a support base can be provided.
  • the sheet-like illumination 8003 is a thin sheet-like illumination device. Since it is attached to the wall surface, it can be used for a wide range of purposes without taking up space. It is easy to increase the area. In addition, it can also be used for the wall surface and housing
  • an illumination device 8004 in which light from a light source is controlled only in a desired direction can be used.
  • a lighting device having a function as furniture can be obtained by applying the light-emitting device which is one embodiment of the present invention to a part of the furniture provided in the room or the light-emitting element which is a part of the light-emitting device. can do.
  • 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.
  • Step 1 Synthesis of 1- (3-bromophenyl-2-yl) -1H-benzimidazole> First, 25.0 g of benzimidazole, 65.9 g of 1-bromo-3-iodobenzene, 8.4 g of 1,10-phenanthroline, 15.8 g of cesium carbonate, 4.4 g of copper iodide, and 500 mL of DMF were placed in a three-necked flask. The inside of the flask was replaced with nitrogen. Then, it stirred at 110 degreeC for 24 hours. After the reaction, extraction with ethyl acetate was performed.
  • Step 2 Synthesis of 1- [3- (4,4,5,5, -tetramethyl-1,3,2-dioxaborolan-2-yl) phenyl] -1H-benzimidazole>
  • 20.8 g of 1- (3-bromophenyl-2-yl) -1H-benzimidazole obtained in Step 1 above 21.6 g of bis (pinacolato) diboron and 1 L of dehydrated dioxane were placed in a three-necked flask, Was replaced with nitrogen.
  • Step 3 Synthesis of 1- [3- (4,6-di-tert-butyl-1,3,5-triazin-2-yl) phenyl] -1H-benzimidazole> Next, 12.8 g of 1- [3- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) phenyl] -1H-benzimidazole obtained in Step 2 above.
  • 2-chloro-4,6-di-tert-butyl-1,3,5-triazine 5.99 g
  • sodium carbonate 105.9 g
  • toluene 500 mL
  • ethanol 250 mL
  • water 500 mL
  • 1.52 g of tetrakis (triphenylphosphine) palladium (0) was added and stirred at 80 ° C. for 10 hours. After the reaction, extraction with toluene was performed.
  • Step 4 Synthesis of 1-methyl-3- [3- (4,6-di-tert-butyl-1,3,5-triazin-2-yl) phenyl] -1H-benzimidazolium iodide>
  • 5.49 g of 1- [3- (4,6-di-tert-butyl-1,3,5-triazin-2-yl) phenyl] -1H-benzimidazole obtained in Step 3 above dehydration 52 mL of toluene was placed in a three-necked flask, and the inside of the flask was purged with nitrogen. After adding 4.4 mL of iodomethane, the mixture was stirred at room temperature for 68 hours.
  • Step 5 Synthesis of fac- [Ir (5tznpmb) 3 ]> Furthermore, 1-methyl-3- [3- (4,6-di-tert-butyl-1,3,5-triazin-2-yl) phenyl] -1H-benzimidazolium iodide obtained in Step 4 above was used. 6.45 g, iridium chloride hydrate (IrCl 3 ⁇ H 2 O) (Fruya Metal Co., Ltd.) 1.08 g, silver (I) 2.81 g, 2-ethoxyethanol 110 mL were placed in a three-neck flask, Was replaced with nitrogen.
  • an ultraviolet-visible absorption spectrum (hereinafter, simply referred to as “absorption spectrum”) and an emission spectrum of fac- [Ir (5tznpmb) 3 ] in a dichloromethane solution were measured.
  • an ultraviolet-visible spectrophotometer (V550 type manufactured by JASCO Corporation) was used, and a dichloromethane solution of 8.1 ⁇ mol / L was put in a quartz cell and measured at room temperature.
  • the emission spectrum was measured using an absolute PL quantum yield measurement device (C11347-01, manufactured by Hamamatsu Photonics Co., Ltd.) and in a glove box (LAB Star M13, manufactured by Bright Co., Ltd., 1250/780) in a nitrogen atmosphere.
  • the dichloromethane deoxygenated solution 8.1 ⁇ mol / L was put in a quartz cell, sealed, 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
  • the vertical axis represents absorption intensity and emission intensity.
  • two solid lines are shown.
  • a thin line represents an absorption spectrum
  • a thick line represents an emission spectrum.
  • the absorption spectrum shown in FIG. 10 shows a result obtained by subtracting an absorption spectrum measured by putting only dichloromethane in a quartz cell from an absorption spectrum measured by putting a dichloromethane solution 8.1 ⁇ mol / L in a quartz cell.
  • the organometallic complex fac- [Ir (5tznpmb) 3 ]
  • fac- [Ir (5tznpmb) 3 ] which is one embodiment of the present invention, has emission peaks at 467 and 489 nm, and blue emission is observed from the dichloromethane solution. It was.
  • an ultraviolet-visible absorption spectrum (hereinafter, simply referred to as “absorption spectrum”) and an emission spectrum of mer- [Ir (5tznpmb) 3 ] in a dichloromethane solution were measured.
  • an ultraviolet-visible spectrophotometer (V550 type manufactured by JASCO Corporation) was used, and 0.010 mmol / L of a dichloromethane solution was placed in a quartz cell and measured at room temperature.
  • the emission spectrum was measured using an absolute PL quantum yield measurement device (C11347-01, manufactured by Hamamatsu Photonics Co., Ltd.) and in a glove box (LAB Star M13, manufactured by Bright Co., Ltd., 1250/780) in a nitrogen atmosphere.
  • the dichloromethane deoxygenated solution 0.010 mmol / L was put in a quartz cell, sealed, 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
  • the vertical axis represents absorption intensity and emission intensity.
  • two solid lines are shown.
  • a thin line represents the absorption spectrum
  • a thick line represents the emission spectrum.
  • the absorption spectrum shown in FIG. 12 shows the result of subtracting the absorption spectrum measured by putting only dichloromethane in a quartz cell from the absorption spectrum measured by putting 0.010 mmol / L of a dichloromethane solution in a quartz cell.
  • the organometallic complex which is one embodiment of the present invention, mer- [Ir (5tznpmb) 3 ], has an emission peak at 487 nm, and blue emission was observed from the dichloromethane solution.
  • the element of the light-emitting element 1 using fac- [Ir (5tznpmb) 3 ] (structural formula (100)) described in Example 1 for a light-emitting layer The structure, manufacturing method, and characteristics thereof will be described. Note that FIG. 13 shows an element structure of a light-emitting element used in this example, and Table 1 shows a specific structure. In addition, chemical formulas of materials used in this example are shown below.
  • the light-emitting element described in this example includes a hole injection layer 911, a hole transport layer 912, a light-emitting layer 913, an electron transport layer 914, and a first electrode 901 formed over a substrate 900.
  • the electron injection layer 915 is sequentially stacked, and the second electrode 903 is stacked on the electron injection layer 915.
  • the first electrode 901 was formed over the substrate 900.
  • the electrode area was 4 mm 2 (2 mm ⁇ 2 mm).
  • a glass substrate was used as the substrate 900.
  • the first electrode 901 was formed by depositing indium tin oxide (ITO) containing silicon oxide with a thickness of 70 nm by a sputtering method.
  • ITO indium tin oxide
  • the surface of the substrate was washed with water and baked at 200 ° C. for 1 hour, followed by UV ozone treatment 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 60 minutes in a heating chamber in the vacuum vapor deposition apparatus, and then the substrate is released for about 30 minutes. Chilled.
  • a hole injection layer 911 was formed over the first electrode 901.
  • the hole-injection layer 911 is obtained by reducing the pressure in the vacuum evaporation apparatus to 10 ⁇ 4 Pa, and then 1,3,5-tri (dibenzothiophen-4-yl) benzene (abbreviation: DBT3P-II) and molybdenum oxide.
  • the hole transport layer 912 was formed by vapor deposition using mCP so as to have a film thickness of 20 nm.
  • a light-emitting layer 913 was formed over the hole transport layer 912.
  • the light-emitting layer 913 uses 1,3-bis (N-carbazolyl) benzene (abbreviation: mCP) as a host material and (OC-6-22) -tris [4- (4,6-di-tert] as a guest material.
  • mCP 1,3-bis (N-carbazolyl) benzene
  • OC-6-22 -tris [4- (4,6-di-tert] as a guest material.
  • 35DCzPPy 3,5-bis (3- (9H-carbazol-9-yl) phenyl) pyridine
  • fac- [Ir (5tznpmb) 3 ] is used as the guest material
  • the film thickness was 10 nm.
  • an electron transport layer 914 was formed over the light emitting layer 913.
  • the electron-transporting layer 914 was formed by vapor deposition so that the film thickness of 1,3,5-tri [(3-pyrylyl) -phen-3-yl] benzene (abbreviation: TmPyPB) was 25 nm.
  • the electron injection layer 915 was formed over the electron transport layer 914.
  • the electron injection layer 915 was formed by vapor deposition using lithium fluoride (LiF) so as to have a film thickness of 1 nm.
  • a second electrode 903 was formed over the electron injection layer 915.
  • the second electrode 903 was formed by vapor deposition of aluminum so that the film thickness becomes 200 nm. Note that in this embodiment, the second electrode 903 functions as a cathode.
  • a light-emitting element in which an EL layer was sandwiched between a pair of electrodes was formed over the substrate 900.
  • 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 described in the above steps are functional layers that constitute the EL layer in one embodiment of the present invention.
  • a vapor deposition method using a resistance heating method was used.
  • the light-emitting element manufactured as described above is sealed by another substrate (not shown).
  • a sealant is applied around the light emitting element formed on the substrate 900 in a glove box in a nitrogen atmosphere, and then a desiccant is provided.
  • Another substrate (not shown) was placed at a desired position on the substrate 900 and irradiated with ultraviolet light of 365 nm at 6 J / cm 2 .
  • the light-emitting element manufactured in this example exhibits favorable element characteristics.
  • FIG. 14 shows an emission spectrum when current is passed through the light-emitting element 1 at a current density of 12.5 mA / cm 2 .
  • the emission spectrum of the light-emitting element 1 has peaks near 463 nm and 486 nm, and is derived from luminescence of fac- [Ir (5tznpmb) 3 ] contained in the light-emitting layer 913. Is suggested.
  • an organometallic complex which is one embodiment of the present invention, fac- [Ir (5tznpmb) 3 ] (structural formula (100)), is obtained by measurement with a high emission quantum yield ( ⁇ ).
  • the emission quantum yield ( ⁇ ) and emission lifetime ( ⁇ ) are shown.
  • ⁇ For the emission lifetime ( ⁇ ), using a picosecond fluorescence lifetime measurement system (manufactured by Hamamatsu Photonics), dichloromethane deoxygenated solution in a glove box (Bright Co., Ltd., LABstar M13 (1250/780) under nitrogen atmosphere. 0.11 mmol / L was placed in a quartz cell, sealed, and measured at room temperature.In this measurement, the solution was irradiated with a pulsed laser in order to measure the lifetime of luminescence exhibited by the solution, and attenuated after the laser irradiation.
  • the solution was irradiated with a 500 ps pulse laser at a period of 10 Hz, and the data measured repeatedly was integrated. Data with a high / N ratio were obtained.
  • the light emission lifetime ( ⁇ ) and the light emission rate constant (K) generally have a relationship represented by the following formula (2).
  • fac- [Ir (5tznpmb) 3 ] having a high emission quantum yield has no radiation loss compared to the radiation deactivation rate constant (K r ) as very large as 2.4 ⁇ 10 4. Since the activation rate constant (K nr ) is as small as 6.7 ⁇ 10 3 , it can be seen that the energy deactivated from the excited state can be efficiently changed to light emission, and a high emission quantum yield is exhibited.
  • fac- [Ir (5tznpmb) 3 ] and mer- [Ir (5tznpmb) 3 ] which is a comparison between facial (fac) and meridiona (mer)
  • a radiation deactivation rate constant although there is not much difference between the two is the K r
  • the radiationless deactivation rate constant K nr
  • luminescent quantum that nonradiative deactivation rate constant of Mel body K nr
  • the organometallic complex which is one embodiment of the present invention is characterized in that a ligand has a triazine skeleton. Therefore, this example shows that the organometallic complex which is one embodiment of the present invention has high emission quantum efficiency.
  • First electrode 102 Second electrode 103 EL layer 103a, 103b EL layer 104 Charge generation layer 111, 111a, 111b Hole injection layer 112, 112a, 112b Hole transport layer 113, 113a, 113b Light emitting layer 114, 114a , 114b Electron transport layer 115, 115a, 115b Electron injection layer 201 First substrate 202 Transistor (FET) 203R, 203G, 203B, 203W Light emitting element 204 EL layer 205 Second substrate 206R, 206G, 206B Color filter 206R ′, 206G ′, 206B ′ Color filter 207 First electrode 208 Second electrode 209 Black layer (black matrix ) 210R, 210G Conductive layer 301 First substrate 302 Pixel portion 303 Drive circuit portion (source line drive circuit) 304a, 304b Drive circuit section (gate line drive circuit) 305 Sealing material 306 Second substrate 307 Route wiring 308 FPC 309 FET 310

Abstract

L'invention concerne un nouveau complexe organométallique. L'invention concerne également un nouveau complexe organométallique qui est efficace pour améliorer les propriétés et la fiabilité du dispositif. Le complexe organométallique de l'invention comprend : un ligand ayant un squelette imidazolyle contenant un carbone de carbène et un squelette triazine ; et de l'iridium. Ce complexe organométallique est représenté par la formule générale (G1). (Dans la formule, R1 à R8 représentent chacun indépendamment l'hydrogène, un groupe alkyle ayant 1 à 6 atomes de carbone, un hydrocarbure saturé monocyclique substitué ou non substitué ayant 5 à 7 atomes de carbone, un hydrocarbure saturé polycyclique substitué ou non substitué ayant de 7 à 10 atomes de carbone, ou un groupe aryle substitué ou non substitué ayant de 6 à 13 atomes de carbone). (De plus, R1 et R2 peuvent former une structure cyclique par une condensation substituée ou non substituée, saturée ou insaturée, la structure cyclique étant un composé cyclique hydrocarboné ou un composé hétérocyclique).
PCT/IB2018/052309 2017-04-14 2018-04-04 Complexe organométallique, élément électroluminescent, dispositif électroluminescent, dispositif électronique et dispositif d'éclairage WO2018189623A1 (fr)

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