JP6241193B2 - Transparent electrode, electronic device, and organic electroluminescence element - Google Patents

Description

  The present invention relates to a transparent electrode, an electronic device, and an organic electroluminescent element, and in particular, has a high transparency, a reduction in sheet resistance, and a long life under high temperature and high humidity storage, and the transparent electrode. The present invention relates to an electronic device and an organic electroluminescence element that are excellent in light transmittance and can reduce a change in rectification ratio under a driving voltage and a constant current.

  An organic electroluminescent element (also referred to as “organic EL element” or “organic electroluminescent element”) using an organic material electroluminescence (hereinafter abbreviated as EL) is about several V to several tens V. It is a thin-film, completely solid element that can emit light at a low voltage, and has many excellent features such as high brightness, high luminous efficiency, thinness, and light weight. For this reason, it has been attracting attention in recent years as surface light emitters such as backlights for various displays, display boards such as signs and emergency lights, and illumination light sources.

  Such an organic EL element has a configuration in which a light emitting layer made of an organic material is sandwiched between two electrodes, and emitted light generated in the light emitting layer passes through the electrode and is extracted outside. For this reason, at least one of the two electrodes is configured as a transparent electrode.

As the transparent electrode, an oxide semiconductor material such as indium tin oxide (SnO ₂ -In ₂ O ₃ : Indium Tin Oxide: ITO) is generally used. Studies have been made on materials aiming at resistance (see, for example, Patent Documents 1 and 2). However, since ITO uses rare metal indium, the material cost is high, and it is necessary to anneal at about 300 ° C. after film formation in order to reduce resistance.

Therefore, a thin film is formed using Zn and Sn as raw materials, and a technology that achieves both transmittance and conductivity by forming a thin film using an alloy of silver and Mg having high electrical conductivity. Techniques have been proposed (see, for example, Patent Documents 3 and 4).
However, in the technology of forming a thin film using an alloy of silver and Mg, the resistance value of the obtained thin film is insufficient at about 100Ω / □, and the deterioration with time is remarkable because Mg is easily oxidized. was there. In addition, in the technology of forming a thin film using Zn or Sn as a raw material, a sufficient resistance value cannot be obtained. A ZnO-based thin film containing Zn is likely to react with water and its performance is likely to fluctuate. The SnO ₂ -based thin film had problems such as being difficult to etch.

In addition, a transparent organic light emitting diode (OLED) in which 15 nm of silver is deposited as a cathode has been reported (for example, see Patent Document 5).
However, in the case of the above-mentioned patent document 5, there is a problem that the light transmittance (transparency) is low because the film thickness of the deposited film made of silver is thick. On the other hand, when the film thickness of the vapor deposition film made of silver is further reduced, the sheet resistance value is increased because a sufficient conductive film is not formed, and the sheet resistance is increased under high temperature and high humidity storage because of easy migration. The change in value becomes large, and the electrode characteristics cannot be maintained. The OLED using such an electrode has a problem that the drive voltage is high and the voltage change under a constant current becomes large.

JP 2002-15623 A Japanese Unexamined Patent Publication No. 2006-164961 JP 2006-344497 A JP 2007-031786 A US Patent Application Publication No. 2011/0260148

  The present invention has been made in view of the above-mentioned problems, and the problem to be solved is a transparent electrode capable of realizing high light transmittance, reduction in sheet resistance, and long life under high temperature and high humidity storage, It is an object to provide an electronic device and an organic electroluminescence element that are excellent in light transmissivity provided with the transparent electrode and can reduce a rectification ratio change under a driving voltage and a constant current.

In order to solve the above problems, the present inventors include a conductive layer and an intermediate layer provided adjacent to the conductive layer in the process of examining the cause of the problem, and the transparent electrode The light transmittance at a wavelength of 550 nm is 50% or more, and the sheet resistance value is 20 Ω / □ or less, and the intermediate layer has a covalent bond site capable of covalently bonding to silver in the molecule, and coordination with silver. It contains an organic compound having both coordination bond sites capable of bonding, and the conductive layer contains silver as a main component, and has excellent light transmittance and sheet resistance. It has been found that a transparent electrode having a low rectification ratio change under a constant current can be realized, and the present invention has been achieved.
That is, the said subject which concerns on this invention is solved by the following means.

1. A transparent electrode comprising a conductive layer and an intermediate layer provided adjacent to the conductive layer,
The transparent electrode has a light transmittance of 50% or more at a wavelength of 550 nm and a sheet resistance value of 20Ω / □ or less,
The intermediate layer contains an organic compound having both a covalent bond site capable of covalently bonding to silver and a coordinate bond site capable of coordinating with silver in the molecule,
The conductive electrode is a vapor-deposited film containing silver as a main component.

  2. 2. The transparent electrode according to item 1, wherein the coordination bond site is a nitrogen atom contained in an aromatic heterocycle and is not involved in aromaticity.

3. The said covalent bond site | part is represented by the following general formula (1) or the following general formula (2), The transparent electrode of 1st term | claim or 2nd term | claim characterized by the above-mentioned.
General formula (1): -SH
Formula (2): —S—S—R
[In the above general formula (2), R represents a substituent. ]

4). 4. The transparent electrode according to claim 1, wherein the number of the coordination binding sites in the molecule is larger than the number of the covalent binding sites.
5. 5. The transparent electrode according to any one of items 1 to 4, wherein the organic compound has a molecular weight of 1200 or less.

6 . A second intermediate layer adjacent to the conductive layer and facing the intermediate layer;
The transparent electrode of any one of the first term, characterized in that the conductive layer is a structure which sandwiches in the intermediate layer and the second intermediate layer to the fifth term.

7 . An electronic device comprising the transparent electrode according to any one of items 1 to 6 .

8 . An organic electroluminescence device comprising the transparent electrode according to any one of items 1 to 6 .

By the above means of the present invention, it is possible to provide a transparent electrode capable of realizing high light transmittance, reduction in sheet resistance, and long life under high temperature / high humidity storage. Moreover, the electronic device and organic electroluminescent element which are excellent in the light transmittance provided with the said transparent electrode, and can reduce the rectification ratio change under a drive voltage and a constant current can be provided.
The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
That is, in the transparent electrode of the present invention, a conductive layer containing silver as a main component is provided on the upper part of the intermediate layer, and the intermediate layer contains atoms having an affinity for silver atoms. A compound having a “covalent bond site capable of covalently bonding to silver (hereinafter simply referred to as a covalent bond site) and a coordinate bond site capable of coordinating with silver (hereinafter simply referred to as a coordinated bond site). It is the structure that "the organic compound provided with both" is contained.
Thus, when the conductive layer is formed on the intermediate layer, the silver atoms constituting the conductive layer contain both the covalent bond site and the coordinate bond site contained in the intermediate layer. Interacting with the organic compound ", the diffusion distance of silver atoms on the surface of the intermediate layer is reduced, and the aggregation of silver at specific locations is suppressed.
That is, the silver atom first forms a two-dimensional nucleus on the surface of the intermediate layer containing the “organic compound having both the covalent bond site and the coordinate bond site” having an affinity for the silver atom, It is formed by growth of a single layer growth type (Frank-van der Merwe: FM type) in which a two-dimensional single crystal layer is formed around this.
In general, an island-shaped growth type (Volume-Weber) in which silver atoms attached on the surface of the intermediate layer are bonded while diffusing the surface to form a three-dimensional nucleus and grow into a three-dimensional island shape. : VW type), it is considered that it is easily formed into an island shape. However, in the present invention, the “organic compound having both the covalent bond site and the coordinate bond site” contained in the intermediate layer It is assumed that island-like growth in this manner is suppressed and single layer growth is promoted.
Therefore, it is possible to obtain a conductive layer having a uniform thickness while having a thin layer thickness. As a result, it is possible to provide a transparent electrode that has a low sheet resistance value and can suppress a change in sheet resistance value under high temperature and high humidity storage while maintaining light transmittance with a thinner layer thickness.

Schematic sectional view showing an example of the configuration of the transparent electrode of the present invention Schematic sectional view showing an example of the configuration of the transparent electrode of the present invention Schematic sectional view showing a first example of an organic EL element to which the transparent electrode of the present invention is applied Schematic sectional view showing a second example of an organic EL element to which the transparent electrode of the present invention is applied Schematic sectional view showing a third example of an organic EL element to which the transparent electrode of the present invention is applied. The schematic sectional drawing which shows an example of the illuminating device which enlarged the light emission surface using the organic EL element provided with the transparent electrode of this invention. Schematic cross-sectional view for explaining the structure of the organic EL device produced in the example

The transparent electrode of the present invention is a transparent electrode comprising a conductive layer and an intermediate layer provided adjacent to the conductive layer, and the transparent electrode has a light transmittance of 50% or more at a wavelength of 550 nm. And the sheet resistance value is 20Ω / □ or less, and the intermediate layer has both a covalent bond site that can be covalently bonded to silver and a coordinate bond site that can be coordinated to silver in the molecule. A compound is contained, and the conductive layer contains silver as a main component. This feature is a technical feature common to the inventions according to claims 1 to 7.
As an embodiment of the present invention, from the viewpoint of expression of the effect of the present invention, the coordination bond site is a nitrogen atom contained in an aromatic heterocycle, and is a nitrogen atom not involved in aromaticity, It is preferable from the viewpoint of improving light transmittance, reducing sheet resistance, and extending the life under high temperature / high humidity storage.

In addition, the covalent bond site is represented by the following general formula (1) or the following general formula (2), so that the light transmission is improved, the sheet resistance value is reduced, and the lifetime is increased under high temperature and high humidity storage. From the point of view, it is preferable.
General formula (1): -SH
Formula (2): —S—S—R
[In the above general formula (2), R represents a substituent. ]

  Moreover, it is preferable that the number of the coordination binding sites in the molecule is larger than the number of the covalent binding sites. Thereby, the covalent bond between silver and the covalent bond site at a certain position can be assisted by the coordinate bond between a plurality of silver and the coordinate bond site.

  Furthermore, it further has a second intermediate layer facing the intermediate layer, and is provided adjacent to both surfaces of the conductive layer to improve light transmittance, reduce sheet resistance, This is preferable from the viewpoint of extending the life under high humidity storage.

  The electronic device of the present invention includes the transparent electrode. Thereby, it is possible to provide an electronic device that is excellent in light transmittance and can reduce a change in rectification ratio under a driving voltage and a constant current.

  The organic electroluminescence element of the present invention is characterized in that the transparent electrode is provided. Thereby, it is possible to obtain an organic electroluminescence element that is excellent in light transmittance and can reduce a change in rectification ratio under a driving voltage and a constant current.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

<< 1. Transparent electrode >>
FIG. 1 is a schematic cross-sectional view showing an example of the configuration of the transparent electrode of the embodiment.

As shown in FIG. 1, the transparent electrode 1 has a two-layer structure in which an intermediate layer 1a and a conductive layer 1b formed on the intermediate layer 1a are stacked. For example, the intermediate layer 1a, The conductive layers 1b are provided in this order. Among these, the intermediate layer 1a is a layer that is configured to contain an organic compound having both a covalent bond site that can be covalently bonded to silver and a coordinate bond site that can be coordinated to silver in the molecule. The conductive layer 1b is a layer containing silver as a main component.
The term “transparent” in the transparent electrode 1 of the present invention means that the light transmittance at a wavelength of 550 nm is 50% or more. Further, the transparent electrode 1 of the present invention has a sheet resistance value of 20Ω / □ or less. Here, the sheet resistance value is a value measured by a 4-terminal 4-probe method constant current application method using a resistivity meter (MCP-T610 manufactured by Mitsubishi Chemical Corporation).
In the present application, the “main component of the conductive layer” refers to a component having the highest constituent ratio among the components constituting the conductive layer. The conductive layer according to the present invention is mainly composed of silver, and the composition ratio is preferably 60% by mass or more. More preferably, it is 80 mass% or more, More preferably, it is 90 mass% or more, Most preferably, it is 98 mass% or more.

  Next, a detailed structure is demonstrated in order of the base material 11 with which the transparent electrode 1 of such a laminated structure is provided, the intermediate | middle layer 1a which comprises the transparent electrode 1, and the electroconductive layer 1b.

[Base material 11]
Examples of the substrate 11 on which the transparent electrode 1 of the present invention is formed include, but are not limited to, glass and plastic. Moreover, the base material 11 may be transparent or opaque. When the transparent electrode 1 of the present invention is used in an electronic device that extracts light from the substrate 11 side, the substrate 11 is preferably transparent. Examples of the transparent substrate 11 that is preferably used include glass, quartz, and a transparent resin film.

  Examples of the glass include silica glass, soda-lime silica glass, lead glass, borosilicate glass, and alkali-free glass. From the viewpoints of adhesion to the intermediate layer 1a, durability, and smoothness, the surface of these glass materials may be subjected to physical treatment such as polishing, if necessary, and from inorganic or organic substances. Or a hybrid film obtained by combining these films may be formed.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, cellulose acetate propionate ( CAP), cellulose esters such as cellulose acetate phthalate, cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones, Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Is mentioned.

On the surface of the resin film, a film made of an inorganic material or an organic material or a hybrid film combining these films may be formed. Such coatings and hybrid coatings have a water vapor transmission rate (25 ± 0.5 ° C., relative humidity 90 ± 2% RH) measured by a method according to JIS-K-7129-1992 of 0.01 g / ( m ² · 24 hours) or less of a barrier film (also referred to as a barrier film or the like) is preferable.
Furthermore, the oxygen permeability measured by a method according to JIS-K-7126-1987 is 1 × 10 ⁻³ ml / (m ² · 24 hours · atm) or less, and the water vapor permeability is 1 × 10 ⁻ A high barrier film of ⁵ g / (m ² · 24 hours) or less is preferable.

The material for forming the barrier film as described above may be a material having a function of suppressing the intrusion of water or oxygen that causes deterioration of the organic EL element, such as silicon dioxide, silicon nitride, etc. Can be used.
Furthermore, in order to improve the brittleness of the barrier film, it is more preferable to have a laminated structure of these inorganic layers and layers (organic layers) made of an organic material. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

  The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, the sputtering method, the reactive sputtering method, the molecular beam epitaxy method, the cluster ion beam method, the ion plating method, the plasma polymerization method, the atmospheric pressure plasma weighting. For example, a plasma CVD method (CVD: Chemical Vapor Deposition), a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but an atmospheric pressure plasma polymerization method described in JP-A-2004-68143 can be used. Is particularly preferred.

  On the other hand, when the base material 11 is opaque, for example, a metal substrate such as aluminum or stainless steel, a film, an opaque resin substrate, a ceramic substrate, or the like can be used.

<Intermediate layer 1a>
The intermediate layer 1a is a layer formed by containing an organic compound having both a covalent bond site that can be covalently bonded to silver and a coordinate bond site that can be coordinated to silver in the molecule.
When such an intermediate layer 1a is formed on the substrate 11, the formation method includes a method using a wet process such as a coating method, an ink-jet method, a coating method, a dip method, or a vapor deposition method (resistance Examples thereof include a method using a dry process such as heating, an EB method (electron beam method), a sputtering method, and a CVD method. Of these, the vapor deposition method is preferably applied.

Furthermore, the intermediate layer 1a preferably has a thickness in the range of 1 to 100 nm, and more preferably in the range of 5 to 30 nm. An effect can be obtained with any thickness within this range.
When the thickness is less than 100 nm, the absorption component of the layer is reduced and the transmittance of the transparent electrode is improved, which is preferable. A thickness of more than 5 nm is preferable because a uniform and continuous intermediate layer is formed.

[Organic compound contained in intermediate layer 1a]
In the transparent electrode 1 of the present invention, the intermediate layer 1a contains an organic compound having both the covalent bond site and the coordination bond site in the molecule.
The coordination bond site is preferably a nitrogen atom contained in an aromatic heterocycle and not involved in aromaticity.

In the present application, the “nitrogen atom having an unshared electron pair not involved in aromaticity” is a nitrogen atom having an unshared electron pair (also referred to as “lone electron pair”), and is an aromatic of an unsaturated cyclic compound. A family member refers to a nitrogen atom in which the unshared electron pair is not directly involved as an essential element. That is, the unshared electron pair is not involved in the delocalized π-electron system on the conjugated unsaturated ring structure (aromatic ring) as an essential element for aromatic expression in the chemical structural formula. Refers to the nitrogen atom.
Details will be described below.

Since the nitrogen atom is a Group 15 element, it has 5 electrons in the outermost shell. Of these, three are used for covalent bonds with other atoms, and the remaining two are a pair of unshared electron pairs, so the number of bonds of nitrogen atoms is usually three.
Thus, for example, an amino group (—NR ¹ R ² ), an amide group (—C (═O) NR ¹ R ² —), a nitro group (—NO ₂ ), a cyano group (—CN), a diazo group (—N = N-), azido group _(-N 3), a urea bond ^{(-NR 1 C = ONR 2 -} ), isothiocyanate group (-N = C = S), thioamide group ^{(-C (= S) NR 1} R ² ) and the like, and these correspond to the “nitrogen atom having an unshared electron pair not involved in aromaticity” in the present invention.

Among these, for example, the resonance formula of a nitro group (—NO ₂ ) can be written as follows. Strictly speaking, an unshared electron pair of a nitrogen atom is used for a resonance structure with an oxygen atom. The nitro group nitrogen atom also has an unshared electron pair.

  On the other hand, the nitrogen atom can also create a fourth bond by utilizing an unshared electron pair. For example, as shown in the following chemical structural formula, tetrabutylammonium chloride is a quaternary ammonium salt in which a fourth butyl group is ionically bonded to a nitrogen atom and has a chloride ion as a counter ion. Tris (2-phenylpyridine) iridium (III) is a neutral metal complex in which an iridium atom and a nitrogen atom are coordinated. Although these compounds have a nitrogen atom, the lone pair of electrons is used for ionic bond and coordinate bond, respectively. Is not applicable.

Therefore, the present invention effectively uses a non-shared electron pair of a nitrogen atom that is not used for bonding.
A nitrogen atom is common as a heteroatom that can constitute an aromatic ring, and can contribute to the expression of aromaticity. Examples of the “nitrogen-containing aromatic ring” include a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazine ring, a pyrrole ring, an imidazole ring, a pyrazole ring, a triazole ring, and a tetrazole ring.

The following chemical structural formula represents the molecular orbital of pyridine.
In the case of a pyridine ring, the number of delocalized π electrons in a conjugated (resonant) unsaturated ring structure arranged in a six-membered ring satisfies the Hückel rule of 4n + 2 (n = 0 or natural number). . Since the nitrogen atom in the six-membered ring is substituted with —CH═, only one unpaired electron is mobilized to the 6π-electron system, and the unshared electron pair is essential for aromatic expression. Not involved as.
Therefore, the nitrogen atom of the pyridine ring corresponds to the “nitrogen atom having an unshared electron pair not involved in aromaticity” in the present invention.

The following chemical structural formula represents the molecular orbital of pyrrole.
In the case of a pyrrole ring, it is a 5-membered heterocyclic structure having one nitrogen atom, but the number of π electrons is 6, and it is a nitrogen-containing aromatic ring that satisfies the Hückel rule. Since the nitrogen atom of the pyrrole ring is also bonded to the hydrogen atom, three electrons are used for σ bond, and the remaining two electrons, that is, unshared electron pairs, are used for π bond. It is an electronic system. Therefore, although the nitrogen atom of the pyrrole ring has an unshared electron pair, it has been utilized as an essential element for the expression of aromaticity. Does not fall under “nitrogen atom”.

The following chemical structural formula represents the molecular orbital of imidazole.
The imidazole ring has a heterocyclic structure containing two nitrogen atoms at the 1- and 3-positions on a 5-membered ring, and is also a nitrogen-containing aromatic ring having 6 π electrons.
The nitrogen atom N ¹ is a pyridine ring-type nitrogen atom in which only one unpaired electron is mobilized to the 6π-electron system, and the unshared electron pair is not used for aromaticity expression. That is, the nitrogen atom N ¹ satisfies the requirements of the present invention, and therefore the nitrogen atom N ¹ of the imidazole ring corresponds to the “nitrogen atom having an unshared electron pair not involved in aromaticity” of the present invention. .
On the other hand, the nitrogen atom N ² is a pyrrole-ring nitrogen atom that mobilizes an unshared electron pair to the 6π electron system. That is, the nitrogen atom N ² does not satisfy the requirements of the present invention, and therefore the nitrogen atom N ² of the imidazole ring corresponds to the “nitrogen atom having an unshared electron pair not involved in aromaticity” of the present invention. do not do.

The same applies to a condensed ring compound having a nitrogen-containing aromatic ring skeleton. For example, δ-carboline represented by the following chemical structural formula is an azacarbazole compound in which a benzene ring skeleton, a pyrrole ring skeleton, and a pyridine ring skeleton are condensed in this order. The nitrogen atom N ³ of the pyridine ring skeleton mobilizes only one electron, and the nitrogen atom N ⁴ of the pyrrole ring skeleton mobilizes an unshared electron pair, respectively, from the carbon atoms forming the ring. The total number of π electrons is an aromatic ring with 14 π electrons. Therefore, among the two nitrogen atoms of δ-carboline, the nitrogen atom N ³ of the pyridine ring skeleton corresponds to the “nitrogen atom having an unshared electron pair not involved in aromaticity” of the present invention, The nitrogen atom N ⁴ is not applicable. Thus, even when the skeleton is incorporated in the condensed ring compound, the nitrogen atom of the pyridine ring or pyrrole ring is not inhibited or suppressed, promoted or promoted, and is not easily involved in the aromaticity. There is no difference when used as a ring.

  The “nitrogen atom having an unshared electron pair not involved in aromaticity” of the present invention is important because the unshared electron pair strongly interacts with silver which is the main component of the conductive layer. Moreover, it is preferable that this nitrogen atom is a nitrogen atom in a nitrogen-containing aromatic ring from a viewpoint of stability and durability.

  The covalent bond site | part of this invention represents the site | part containing the atom which can form a covalent bond with a silver atom. Although the specific example of the compound before and behind forming a covalent bond with a silver atom is shown below, it is not limited to these.

Moreover, it is preferable that the said covalent bond site | part is represented by following General formula (1) or following General formula (2).
General formula (1): -SH
Formula (2): —S—S—R
[In the above general formula (2), R represents a substituent. ]

Specific examples of the general formula (1) include alkane thiol, aromatic hydrocarbon ring thiol, aromatic heterocyclic thiol and the like.
In the general formula (2), examples of the substituent represented by R include a hydrogen atom, a linear aliphatic hydrocarbon group, a branched aliphatic hydrocarbon group, and a linear unsaturated aliphatic hydrocarbon group. A branched unsaturated aliphatic hydrocarbon group, an aromatic hydrocarbon group, an aromatic heterocyclic group, and the like.
Specific examples of the general formula (2) include alkane disulfide, alkene disulfide, alkyne disulfide, aromatic hydrocarbon ring disulfide, aromatic heterocyclic disulfide and the like.

  The coordinate bond site | part of this invention represents the site | part containing the atom in which a silver atom can form a coordinate bond. Although the specific example of the compound before and behind forming a silver atom and a coordinate bond is shown below, it is not limited to these.

  Since the compound of the present invention contained in the intermediate layer has both a covalent bond site and a coordinate bond site in the molecule, it is more strongly bonded to a silver atom, and is a transparent electrode excellent in conductivity and light transmittance. Can be produced. The estimation of the state of these bonds is shown in the following chemical structural formula. However, this is not always the case at all locations on the interface between the intermediate layer and the conductive layer.

  The number of coordination binding sites in the molecule is preferably larger than the number of covalent binding sites.

  The skeleton having a common binding site and a coordination binding site is not particularly limited, and any structure can be used as long as the effects of the present invention can be obtained.

  The skeleton preferably contains mainly an aromatic ring, more preferably an aromatic ring only.

<Specific examples of organic compounds applicable to the intermediate layer 1a>
Specific examples of organic compounds that can be contained in the intermediate layer 1a according to the present invention and have both the covalent bond site and the coordinate bond site in the molecule are shown below, but are not limited thereto. is not.

[Conductive layer 1b]
The conductive layer 1b according to the present invention is a layer containing silver as a main component and formed on the intermediate layer 1a. As a method of forming such a conductive layer 1b, a method using a wet process such as a coating method, an ink jet method, a coating method, a dip method, a vapor deposition method (resistance heating, EB method, etc.), a sputtering method, a CVD method, etc. And a method using the dry process. Of these, the vapor deposition method is preferably applied.
In addition, the conductive layer 1b is formed on the intermediate layer 1a, so that the conductive layer 1b has sufficient conductivity even without a high-temperature annealing treatment (for example, a heating process at 150 ° C. or higher) after the formation of the conductive layer. However, if necessary, it may be subjected to high-temperature annealing after formation.

The conductive layer 1b may be composed of an alloy containing silver (Ag). Examples of such an alloy include silver / magnesium (Ag / Mg), silver / copper (Ag / Cu), silver, and the like. -Palladium (Ag * Pd), silver * palladium * copper (Ag * Pd * Cu), silver * indium (Ag * In), etc. are mentioned.
The silver content needs to be 50% or more, and preferably 90% or more.

  The conductive layer 1b according to the present invention may have a configuration in which a layer containing silver as a main component is divided into a plurality of layers as necessary.

  Furthermore, the conductive layer 1b preferably has a thickness in the range of 5 to 20 nm, and more preferably in the range of 5 to 8 nm. When the thickness is less than 20 nm, the absorption component or reflection component of the layer is reduced, and the transmittance of the transparent electrode is improved, which is more preferable. A thickness of more than 5 nm is preferable because the conductivity of the layer is sufficient.

In addition, in the transparent electrode 1 having the laminated structure including the intermediate layer 1a and the conductive layer 1b formed thereon, the upper part of the conductive layer 1b may be covered with a protective film. Another conductive layer may be laminated. In this case, it is preferable that the protective film and another conductive layer have light transmittance so that the light transmittance of the transparent electrode 1 is not impaired.
Moreover, it is good also as a structure which provided the layer as needed also under the intermediate | middle layer 1a, ie, between the intermediate | middle layer 1a and the base material 11.

[Effect of transparent electrode 1]
As described above, the transparent electrode 1 according to the present invention is mainly composed of silver on the intermediate layer 1a formed using an organic compound having both the covalent bond site and the coordinate bond site in the molecule. It is the structure which provided the electroconductive layer 1b contained as. As a result, when the conductive layer 1b is formed on the intermediate layer 1a, the silver atoms constituting the conductive layer 1b are bonded to the covalent bond site and the coordinate bond site within the molecule constituting the intermediate layer 1a. By interacting with an organic compound having both, the diffusion distance of silver atoms on the surface of the intermediate layer 1a can be reduced, and the formation of silver aggregates can be suppressed.

  Here, in general, in the formation of the conductive layer 1b containing silver as a main component, a thin film is grown in a nucleus growth type (Volume-Weber: VW type), so that silver particles are isolated in an island shape. When the layer thickness is thin, it becomes difficult to obtain conductivity, and the sheet resistance value becomes high. Therefore, in order to ensure conductivity, the layer thickness needs to be increased to some extent. However, if the layer thickness is increased, the light transmittance is lowered, which is not suitable as a transparent electrode.

  However, according to the transparent electrode 1 having the configuration defined in the present invention, since aggregation of silver is suppressed on the intermediate layer 1a as described above, in the formation of the conductive layer 1b containing silver as a main component, Then, a single layer growth type (Frank-van der Merwe: FM type) thin film is grown.

In the present invention, “transparent electrode 1” means that the light transmittance at a wavelength of 550 nm is 50% or more. However, each of the materials used as the intermediate layer 1a is mainly composed of silver. Compared to the conductive layer 1b described above, the film is a good film having sufficient light transmittance. On the other hand, the conductivity of the transparent electrode 1 is ensured mainly by the conductive layer 1b.
Therefore, as described above, the conductive layer 1b containing silver as a main component has a smaller thickness and the conductivity is ensured, thereby improving the light transmittance of the transparent electrode 1, and the sheet. It is possible to reduce the resistance value and extend the life under high temperature / high humidity storage.

As shown in FIG. 2, the transparent electrode 1 has another intermediate layer 1c (hereinafter referred to as “second intermediate layer”) on top of the conductive layer 1b (hereinafter also referred to as “first intermediate layer 1a”). 1c ") may be stacked. That is, the transparent electrode 1 further includes a second intermediate layer 1c adjacent to the conductive layer 1b and facing the first intermediate layer 1a, and the conductive layer 1b includes the first intermediate layer 1a and the first intermediate layer 1a. The structure may be sandwiched between two intermediate layers 1c.
The second intermediate layer 1c is a layer formed using an organic compound containing a sulfur atom having an unshared electron pair, similar to the first intermediate layer 1a. As described above, the conductive layer 1b is sandwiched between the first intermediate layer 1a and the second intermediate layer 1c, so that the silver atoms constituting the conductive layer 1b are changed between the first intermediate layer 1a and the second intermediate layer 1b. It interacts with the “organic compound having both the covalent bond site and the coordination bond site in the molecule” constituting the layer 1c, and on the surface of the first intermediate layer 1a and the second intermediate layer 1c of silver atoms. The diffusion distance is reduced, and the formation of silver agglomeration can be more reliably suppressed. As a result, it is possible to obtain a transparent electrode that can secure sufficient conductivity, improve light transmittance, reduce sheet resistance, and extend the life under high temperature and high humidity storage.

<< 2. Applications of transparent electrodes >>
The transparent electrode 1 of the present invention having the above configuration can be used for various electronic devices. Examples of electronic devices include organic EL elements, LEDs (light emitting diodes), liquid crystal elements, solar cells, touch panels, etc. In these electronic devices, the present invention is used as an electrode member that requires light transmission. The transparent electrode 1 can be used.

  Hereinafter, as an example of the application, an embodiment of an organic EL element using a transparent electrode will be described.

<< 3. First Example of Organic EL Device >>
[Configuration of Organic EL Element 100]
FIG. 3 is a cross-sectional configuration diagram illustrating a first example of an organic EL element including the transparent electrode 1 of the present invention as an example of the electronic device of the present invention. Hereinafter, the configuration of the organic EL element will be described with reference to FIG.

  The organic EL element 100 shown in FIG. 3 is provided on a transparent substrate (base material) 13, and in order from the transparent substrate 13 side, the light emitting functional layer 3 configured using the transparent electrode 1, an organic material, and the like, and The counter electrode 5a is laminated in this order. In the organic EL element 100, the transparent electrode 1 of the present invention described above is used as the transparent electrode 1. For this reason, the organic EL element 100 is configured to extract the generated light (hereinafter referred to as emission light h) from at least the transparent substrate 13 side.

Moreover, although the layer structure of the organic EL element 100 is demonstrated below, it is not limited to these structural examples illustrated, A general layer structure may be sufficient. In the configuration shown in FIG. 3, the transparent electrode 1 functions as an anode (that is, an anode), and the counter electrode 5a functions as a cathode (that is, a cathode). In this case, for example, as shown in FIG. 3, the light-emitting functional layer 3 includes a hole injection layer 3a / a hole transport layer 3b / a light-emitting layer 3c / an electron transport layer 3d / an electron injection layer in order from the transparent electrode 1 side that is an anode. Although the structure which laminated | stacked 3e is illustrated, it is essential to have the light emitting layer 3c comprised among these at least using the organic material.
The hole injection layer 3a and the hole transport layer 3b may be provided as a hole transport / injection layer.
The electron transport layer 3d and the electron injection layer 3e may be provided as an electron transport / injection layer.
Of these light emitting functional layers 3, for example, the electron injection layer 3e may be made of an inorganic material.

In addition to these exemplified constituent layers, the light-emitting functional layer 3 may have a hole blocking layer, an electron blocking layer, or the like laminated as necessary. Furthermore, the light emitting layer 3c may have a structure in which each color light emitting layer that generates emitted light in each wavelength region is laminated, and each of these color light emitting layers is laminated via a non-light emitting intermediate layer.
The intermediate layer may function as a hole blocking layer and an electron blocking layer. Furthermore, the counter electrode 5a, which is a cathode, may also have a laminated structure as necessary. In such a configuration, only a portion where the light emitting functional layer 3 is sandwiched between the transparent electrode 1 and the counter electrode 5 a becomes a light emitting region in the organic EL element 100.

  In the layer configuration as described above, the auxiliary electrode 15 may be provided in contact with the conductive layer 1 b of the transparent electrode 1 for the purpose of reducing the resistance of the transparent electrode 1.

The organic EL element 100 having the above configuration is sealed with a sealing material 17 described later on the transparent substrate 13 for the purpose of preventing deterioration of the light emitting functional layer 3 formed using an organic material or the like. ing.
The sealing material 17 is fixed to the transparent substrate 13 side with an adhesive 19. However, the terminal portions of the transparent electrode 1 and the counter electrode 5a are provided on the transparent substrate 13 so as to be exposed from the sealing material 17 while being insulated from each other by the light emitting functional layer 3.

  Hereinafter, details of the main layers for constituting the organic EL element 100 shown in FIG. 3 are described in detail for the transparent substrate 13, the transparent electrode 1, the counter electrode 5 a, the light emitting layer 3 c of the light emitting functional layer 3, The layer, the auxiliary electrode 15, and the sealing material 17 will be described in this order. Thereafter, a method for producing the organic EL element 100 will be described.

(Transparent substrate 13)
The transparent substrate 13 is the base material 11 on which the transparent electrode 1 of the present invention described above is provided, and the transparent base material 11 having light transmittance among the base materials 11 described above is used.

(Transparent electrode 1)
The transparent electrode 1 (anode: anode) is the transparent electrode 1 of the present invention described above, and has a configuration in which the intermediate layer 1a and the conductive layer 1b are sequentially formed from the transparent substrate 13 side. Here, in particular, the transparent electrode 1 functions as an anode (anode), and the conductive layer 1b is a substantial anode.

(Counter electrode 5a)
The counter electrode 5a (cathode: cathode) is an electrode film that functions as a cathode (cathode) for supplying electrons to the light emitting functional layer 3, and includes, for example, a metal, an alloy, an organic or inorganic conductive compound, or a mixture thereof. It is composed of
Specifically, aluminum, silver, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, indium, lithium / aluminum mixture, rare earth metal, ITO, ZnO, TiO ₂ , An oxide semiconductor such as SnO ₂ can be given.

  The counter electrode 5a can be produced by forming a thin film of these conductive materials by a method such as vapor deposition or sputtering. The sheet resistance value as the counter electrode 5a is preferably several hundred Ω / □ or less, and the film thickness is usually selected within the range of 5 nm to 5 μm, preferably within the range of 5 to 200 nm.

  In addition, when this organic EL element 100 takes out the emitted light h also from the counter electrode 5a side, the counter electrode is made of a conductive material having a good light transmission property selected from the above-described conductive materials. 5a should just be comprised.

(Light emitting layer 3c)
The light emitting layer 3c used in the present invention contains a light emitting material, and among them, a phosphorescent light emitting compound is preferably contained as the light emitting material.

  The light emitting layer 3c is a layer that emits light by recombination of electrons injected from the electrode or the electron transport layer 3d and holes injected from the hole transport layer 3b, and the light emitting portion is the light emitting layer 3c. Even within the layer, it may be the interface between the light emitting layer 3c and the adjacent layer.

  There is no restriction | limiting in particular in the structure as such a light emitting layer 3c, if the light emitting material contained satisfies the light emission requirements. Moreover, there may be a plurality of layers having the same emission spectrum and emission maximum wavelength. In this case, it is preferable to have a non-light emitting auxiliary layer between the light emitting layers 3c.

  The total thickness of the light emitting layer 3c is preferably in the range of 1 to 100 nm, and more preferably in the range of 1 to 30 nm because a lower driving voltage can be obtained. In addition, the sum total of the thickness of the light emitting layer 3c is a thickness also including the said auxiliary layer, when a nonluminous auxiliary layer exists between the light emitting layers 3c.

  In the case of the light emitting layer 3c having a configuration in which a plurality of layers are laminated, the thickness of each light emitting layer is preferably adjusted within a range of 1 to 50 nm, and more preferably adjusted within a range of 1 to 20 nm. When the plurality of stacked light emitting layers correspond to the respective emission colors of blue, green, and red, there is no particular limitation on the relationship between the thicknesses of the blue, green, and red light emitting layers.

  The light emitting layer 3c configured as described above is formed by forming a light emitting material or a host compound, which will be described later, by a known thin film forming method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, or an ink jet method. Can be formed.

  In addition, the light emitting layer 3c may be configured by mixing a plurality of light emitting materials, and is configured by mixing a phosphorescent light emitting material and a fluorescent light emitting material (hereinafter also referred to as a fluorescent dopant or a fluorescent compound). It may be.

  As a structure of the light emitting layer 3c, it is preferable to contain a host compound (also referred to as a light emitting host or the like) and a light emitting material (also referred to as a light emitting dopant compound or a dopant compound) to emit light.

<Host compound>
As the host compound contained in the light emitting layer 3c, a compound having a phosphorescence quantum yield of phosphorescence emission at room temperature (25 ° C.) of less than 0.1 is preferable. More preferably, the phosphorescence quantum yield is less than 0.01. Moreover, it is preferable that the volume ratio in the layer is 50% or more among the compounds contained in the light emitting layer 3c.

  As a host compound, a well-known host compound may be used independently, or multiple types may be used. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. In addition, by using a plurality of kinds of light emitting materials described later, it is possible to mix different light emission, thereby obtaining an arbitrary light emission color.

  The host compound used may be a conventionally known low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (evaporation polymerizable light emitting host). .

As the known host compound, a compound having a hole transporting ability and an electron transporting ability while preventing the emission of light from being increased in wavelength and having a high Tg (glass transition temperature) is preferable.
Glass transition temperature (Tg) here is a value calculated | required by the method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry: Differential scanning calorimetry).

  Although the specific example (H1-H79) of the host compound which can be used by this invention below is shown, it is not limited to these. In the host compound H68, x and y represent the ratio of the random copolymer, and in the host compound H69, p, q, and r represent the ratio of the random copolymer. The ratio can be, for example, x: y = 1: 10.

  Specific examples of known host compounds include compounds described in the following documents. For example, Japanese Patent Application Laid-Open Nos. 2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860 Gazette, 2002-334787 gazette, 2002-15871 gazette, 2002-334788 gazette, 2002-43056 gazette, 2002-334789 gazette, 2002-75645 gazette, 2002-338579 gazette. No. 2002-105445, No. 2002-343568, No. 2002-141173, No. 2002-352957, No. 2002-203683, No. 2002-363227, No. 2002-231453. No. 2003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060. , 2002-302516, 2002-305083, 2002-305084, 2002-308837 and the like.

<Light emitting material>
Examples of the light-emitting material (light-emitting dopant compound or dopant compound) that can be used in the present invention include phosphorescent compounds (also referred to as phosphorescent compounds and phosphorescent materials).

  A phosphorescent compound is a compound in which light emission from an excited triplet is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25 ° C.), and the phosphorescence quantum yield is 0 at 25 ° C. A preferred phosphorescence quantum yield is 0.1 or more, although it is defined as 0.01 or more compounds.

The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition.
The phosphorescence quantum yield in the solution can be measured using various solvents, but when using a phosphorescent compound in the present invention, the phosphorescence quantum yield is 0.01 or more in any solvent. Should be achieved.

There are two types of light emission principles of the phosphorescent compound. One method is that the carrier recombination occurs on the host compound to which the carrier is transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent compound to transfer the energy from the phosphorescent compound. It is an energy transfer type that obtains luminescence.
Another method is a carrier trap type in which a phosphorescent compound serves as a carrier trap, carrier recombination occurs on the phosphorescent compound, and light emission from the phosphorescent compound is obtained.
In either case, the condition is that the excited state energy of the phosphorescent compound is lower than the excited state energy of the host compound.

  The phosphorescent compound can be appropriately selected from known compounds used for the light emitting layer of a general organic EL device, but preferably contains a group 8-10 metal in the periodic table of elements. More preferred are iridium compounds, more preferred are iridium compounds, osmium compounds, platinum compounds (platinum complex compounds), and rare earth complexes, and most preferred are iridium compounds.

  In the present invention, at least one light emitting layer 3c may contain two or more phosphorescent compounds, and the concentration ratio of the phosphorescent compound in the light emitting layer 3c is the thickness direction of the light emitting layer 3c. It may be an aspect that changes.

  The phosphorescent compound is preferably in the range of 0.1 volume% or more and less than 30 volume% with respect to the total amount of the light emitting layer 3c.

<Compound represented by formula (A)>
The light emitting layer 3c according to the present invention preferably contains a compound represented by the following general formula (A) as the phosphorescent compound.

  The phosphorescent compound represented by the following general formula (A) (also referred to as a phosphorescent metal complex) is preferably contained in the light emitting layer 3c of the organic EL element 100 as a light emitting dopant. However, it may be contained in a light emitting functional layer other than the light emitting layer 3c.

In the general formula (A), P and Q each represent a carbon atom or a nitrogen atom, and A ₁ represents an atomic group that forms an aromatic hydrocarbon ring or an aromatic heterocyclic ring together with P—C.
A ₂ represents an atomic group that forms an aromatic heterocycle with QN.
P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom, or an oxygen atom.
L ₁ represents an atomic group that forms a bidentate ligand together with P ₁ and P ₂ .
j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3.
M ₁ represents a transition metal element of Group 8 to Group 10 in the periodic table.

  In general formula (A), P and Q each represent a carbon atom or a nitrogen atom.

In the general formula (A), examples of the aromatic hydrocarbon ring that A ₁ forms with PC include a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, and a chrysene ring. , Naphthacene ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring , Picene ring, pyrene ring, pyranthrene ring, anthraanthrene ring and the like.

  These rings may further have a substituent. Examples of such a substituent include an alkyl group (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a tert-butyl group, a pentyl group). Hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (for example, vinyl group, allyl group, etc.), alkynyl group (For example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon group (also called aromatic carbocyclic group, aryl group, etc.), for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group , Anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl , Pyrenyl group, biphenylyl group, etc.), aromatic heterocyclic group (for example, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl group, A carbazolyl group, a carbolinyl group, a diazacarbazolyl group (representing one in which any carbon atom constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a phthalazinyl group, etc.), a heterocyclic group (for example, Pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (For example, cyclopentyloxy group Cyclohexyloxy group etc.), aryloxy group (eg phenoxy group, naphthyloxy group etc.), alkylthio group (eg methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group etc.), cyclo An alkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), an arylthio group (eg, phenylthio group, naphthylthio group, etc.), an alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyl) Oxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfuryl group, etc.) Phenyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2- Pyridylaminosulfonyl group, etc.), acyl groups (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl) Group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octyl group) Rucarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (eg, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino) Group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, Propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylamino Rubonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group) , Dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group) , Phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfo group) Nyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), Amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, piperidinyl group (piperidinyl group) Group), 2,2,6,6-tetramethylpiperidinyl group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, Trifluoromethyl group, penta Fluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphate ester Examples include a group (for example, dihexyl phosphoryl group), a phosphite group (for example, diphenylphosphinyl group), a phosphono group, and the like.

In the general formula (A), the aromatic heterocycle formed by A ₁ together with P—C includes a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, and a triazine. Ring, benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring, And azacarbazole ring.

  Here, the azacarbazole ring represents one in which at least one carbon atom of the benzene ring constituting the carbazole ring is replaced with a nitrogen atom.

  These rings may further have the above-described substituent.

In the general formula (A), examples of the aromatic heterocycle formed by A ₂ together with QN include an oxazole ring, an oxadiazole ring, an oxatriazole ring, an isoxazole ring, a tetrazole ring, a thiadiazole ring, a thiatriazole ring, Examples include isothiazole ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, pyrazole ring, and triazole ring.

  These rings may further have the above-described substituent.

In the general formula (A), P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom, or an oxygen atom.
L ₁ represents an atomic group that forms a bidentate ligand together with P ₁ and P ₂ .

Examples of the bidentate ligand represented by P ₁ -L ₁ -P ₂ include phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabol, acetylacetone, and picolinic acid.

  In the general formula (A), j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, j1 + j2 represents 2 or 3, and j2 is preferably 0. .

In General Formula (A), M ₁ is a transition metal element belonging to Group 8 to 10 in the periodic table of elements (also simply referred to as a transition metal), and is preferably iridium.

<Compound represented by formula (B)>
Among the compounds represented by the general formula (A) described above, a compound represented by the following general formula (B) is more preferable.

In the general formula (B), Z represents a hydrocarbon ring group or a heterocyclic group. P and Q each represent a carbon atom or a nitrogen atom, and A ₁ represents an atomic group that forms an aromatic hydrocarbon ring or an aromatic heterocyclic ring together with P—C.
A ₃ represents -C (R ₀₁ ) = C (R ₀₂ )-, -N = C (R ₀₂ )-, -C (R ₀₁ ) = N- or -N = N-, and R ₀₁ , R ₀₂ each represents a hydrogen atom or a substituent.
P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom, or an oxygen atom.
L ₁ represents an atomic group that forms a bidentate ligand together with P ₁ and P ₂ .
j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3.
M ₁ represents a transition metal element of Group 8 to Group 10 in the periodic table.

  In the general formula (B), examples of the hydrocarbon ring group represented by Z include a non-aromatic hydrocarbon ring group and an aromatic hydrocarbon ring group, and examples of the non-aromatic hydrocarbon ring group include a cyclopropyl group. , Cyclopentyl group, cyclohexyl group and the like. These groups may be unsubstituted or have a substituent described later.

  Examples of the aromatic hydrocarbon ring group (also referred to as aromatic hydrocarbon group, aryl group, etc.) include, for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl. Group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group and the like.

These groups may be unsubstituted or may have a substituent. Examples of such a substituent include a substituent that the ring represented by A ₁ in General Formula (A) may have. The same thing as a group is mentioned.

In the general formula (B), examples of the heterocyclic group represented by Z include a non-aromatic heterocyclic group and an aromatic heterocyclic group.
Non-aromatic heterocyclic groups include, for example, epoxy ring, aziridine ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene Ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε-caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydropyran ring, 1,3-dioxane ring, 1, And groups derived from 4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine ring, thiomorpholine-1,1-dioxide ring, pyranose ring, diazabicyclo [2,2,2] -octane ring, and the like. .

These groups may be unsubstituted or may have a substituent. Examples of such a substituent include a substituent that the ring represented by A ₁ in General Formula (A) may have. The same thing as a group is mentioned.

  Examples of the aromatic heterocyclic group include pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl). Group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group , Benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (representing one of the carbon atoms constituting the carboline ring of the carbolinyl group replaced by a nitrogen atom), quinoxalinyl Group, pyridazinyl group, triazinyl group, key Zoriniru group, phthalazinyl group, and the like.

These groups may be unsubstituted or may have a substituent. Examples of such a substituent include a substituent that the ring represented by A ₁ in General Formula (A) may have. The same thing as a group is mentioned.

  Preferably, the group represented by Z is an aromatic hydrocarbon ring group or an aromatic heterocyclic group.

In the general formula (B), the aromatic hydrocarbon ring formed by A ₁ together with P—C includes benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene. Ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene And a ring, a pyrene ring, a pyranthrene ring, and an anthraanthrene ring.

These rings may further have a substituent, such as the substituent of the general formula (A) similar to the substituent which may be possessed by the ring represented by A ₁ in Is mentioned.

In the general formula (B), the aromatic heterocycle formed by A ₁ together with P—C includes a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, and a triazine ring. , Benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring, carboline Ring, azacarbazole ring and the like.

  Here, the azacarbazole ring represents one in which at least one carbon atom of the benzene ring constituting the carbazole ring is replaced with a nitrogen atom.

These rings may further have a substituent, such as the substituent of the general formula (A) similar to the substituent which may be possessed by the ring represented by A ₁ in Is mentioned.

In -C (R ₀₁ ) = C (R ₀₂ )-, -N = C (R ₀₂ )-, -C (R ₀₁ ) = N- represented by A ₃ in the general formula (B), R ₀₁ , R ₀₂ each has the same definition as the substituent that the ring represented by A ₁ in formula (A) may have.

In the general formula (B), examples of the bidentate ligand represented by P ₁ -L ₁ -P ₂ include phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabol, acetylacetone, picolinic acid, and the like. Is mentioned.

  J1 represents an integer of 1 to 3, and j2 represents an integer of 0 to 2, j1 + j2 represents 2 or 3, and j2 is preferably 0.

In the general formula (B), the transition metal element of group 8 to 10 in the periodic table of elements represented by M ₁ (also simply referred to as transition metal) is the element periodic table represented by M ₁ in the general formula (A). Are synonymous with the group 8-10 transition metal elements.

<Compound represented by formula (C)>
In this invention, the compound represented by the following general formula (C) is mentioned as one of the preferable aspects of the compound represented by the said general formula (B).

In the general formula (C), R ₀₃ represents a substituent, R ₀₄ represents a hydrogen atom or a substituent, and a plurality of R ₀₄ may be bonded to each other to form a ring.
n01 represents an integer of 1 to 4.
R ₀₅ represents a hydrogen atom or a substituent, and a plurality of R ₀₅ may be bonded to each other to form a ring. n02 represents an integer of 1 to 2.
R ₀₆ represents a hydrogen atom or a substituent, and may combine with each other to form a ring.
n03 represents an integer of 1 to 4.
Z ₁ represents an atomic group necessary for forming a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocycle together with C—C.
Z ₂ represents an atomic group necessary for forming a hydrocarbon ring group or a heterocyclic group.
P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom.
L ₁ represents an atomic group that forms a bidentate ligand together with P ₁ and P ₂ .
j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3.
M ₁ represents a transition metal element of Group 8 to Group 10 in the periodic table.
R ₀₃ and R ₀₆ , R ₀₄ and R _06, and R ₀₅ and R ₀₆ may be bonded to each other to form a ring.

In the general formula (C), each of the substituents represented by R ₀₃ , R ₀₄ , R ₀₅ , and R ₀₆ is a substituent that the ring represented by A ₁ in the general formula (A) may have. It is synonymous with.

In the general formula (C), examples of the 6-membered aromatic hydrocarbon ring formed by Z ₁ together with C—C include a benzene ring.

These rings may further have a substituent, and examples of the substituent of the general formula (A) similar to the substituent which may be possessed by the ring represented by A ₁ in Is mentioned.

In the general formula (C), examples of the 5-membered or 6-membered aromatic heterocycle formed by Z ₁ together with C—C include an oxazole ring, an oxadiazole ring, an oxatriazole ring, an isoxazole ring, and a tetrazole ring. , Thiadiazole ring, thiatriazole ring, isothiazole ring, thiophene ring, furan ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, pyrazole ring, triazole ring and the like.

These rings may further have a substituent, and examples of the substituent of the general formula (A) similar to the substituent which may be possessed by the ring represented by A ₁ in Is mentioned.

In the general formula (C), examples of the hydrocarbon ring group represented by Z ₂ include a non-aromatic hydrocarbon ring group and an aromatic hydrocarbon ring group.
Examples of the non-aromatic hydrocarbon ring group include a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group. These groups may be unsubstituted or may have a substituent. Examples of such a substituent include a substituent that the ring represented by A ₁ in General Formula (A) may have. The same thing as a group is mentioned.

Examples of the aromatic hydrocarbon ring group (also referred to as aromatic hydrocarbon group, aryl group, etc.) include, for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl. Group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group and the like. These groups may be unsubstituted or may have a substituent. Examples of such a substituent include a substituent that the ring represented by A ₁ in General Formula (A) may have. The same thing as a group is mentioned.

In the general formula (C), examples of the heterocyclic group represented by Z ₂ include a non-aromatic heterocyclic group and an aromatic heterocyclic group.
Non-aromatic heterocyclic groups include, for example, epoxy ring, aziridine ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene Ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε-caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydropyran ring, 1,3-dioxane ring, 1, Examples include groups derived from 4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine ring, thiomorpholine-1,1-dioxide ring, pyranose ring, diazabicyclo [2,2,2] -octane ring, etc. Can do. These groups may be unsubstituted or may have a substituent. Examples of such a substituent include a substituent that the ring represented by A ₁ in the general formula (A) may have. The same thing is mentioned.

  Examples of the aromatic heterocyclic group include pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl). Group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group , Benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (representing one of the carbon atoms constituting the carboline ring of the carbolinyl group replaced by a nitrogen atom), quinoxalinyl group , Pyridazinyl group, triazinyl group, quina Riniru group, phthalazinyl group, and the like.

These rings may be unsubstituted or may have a substituent. Examples of such a substituent include the substituent that the ring represented by A ₁ in the general formula (A) may have. The same thing is mentioned.

In the general formula (C), the group formed by Z ₁ and Z ₂ is preferably a benzene ring.

In formula _(C), bidentate ligand represented by P 1 _-L 1 -P ₂ is In formula _(A), coordination of bidentate represented by P 1 _-L 1 -P ₂ Synonymous with rank.

In the formula (C), transition metal elements of Group 8 to Group 10 in the periodic table represented by _{M 1} is In formula (A), the transition of 8-10 in the periodic table represented by _{M 1} Synonymous with metal element.

  The phosphorescent compound can be appropriately selected from known compounds used for the light emitting layer 3 c of the organic EL element 100.

  The phosphorescent compound according to the present invention is preferably a complex compound containing a group 8-10 metal in the periodic table of elements, more preferably an iridium compound, an osmium compound, or a platinum compound (platinum complex). System compounds), rare earth complexes, and most preferred are iridium compounds.

  Specific examples (Pt-1 to Pt-3, A-1, Ir-1 to Ir-45) of the phosphorescent compound according to the present invention are shown below, but the present invention is not limited thereto. In these compounds, m and n represent the number of repetitions.

  The phosphorescent compound (also referred to as a phosphorescent metal complex) is described in, for example, Organic Letter, vol. 16, 2579-2581 (2001), Inorganic Chemistry, Vol. 30, No. 8, 1685-1687 (1991), J. Am. Am. Chem. Soc. , 123, 4304 (2001), Inorganic Chemistry, Vol. 40, No. 7, 1704-1711 (2001), Inorganic Chemistry, Vol. 41, No. 12, 3055-3066 (2002) , New Journal of Chemistry. , Vol. 26, 1171 (2002), European Journal of Organic Chemistry, Vol. 4, pages 695-709 (2004), and synthesis by applying methods such as references described in these documents. it can.

<Fluorescent material>
Fluorescent materials include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes, stilbene dyes Examples thereof include dyes, polythiophene dyes, and rare earth complex phosphors.

(Injection layer)
The injection layers (the hole injection layer 3a and the electron injection layer 3e) are layers provided between the electrode and the light emitting layer 3c in order to lower the driving voltage and improve the light emission luminance. It is described in detail in Volume 2, Chapter 2, “Electrode Materials” (pages 123-166) of the front line (published by NTS, November 30, 1998), and the hole injection layer 3a and electron injection There is a layer 3e.

  The injection layer can be provided as necessary. The hole injection layer 3a may be present between the anode and the light emitting layer 3c or the hole transport layer 3b, and the electron injection layer 3e may be present between the cathode and the light emitting layer 3c or the electron transport layer 3d. .

  The details of the hole injection layer 3a are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069, and the like. Specific examples thereof include phthalocyanine represented by copper phthalocyanine. Examples thereof include a layer, an oxide layer typified by vanadium oxide, an amorphous carbon layer, and a polymer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The details of the electron injection layer 3e are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like, and specifically represented by strontium, aluminum and the like. Examples thereof include a metal layer, an alkali metal halide layer typified by potassium fluoride, an alkaline earth metal compound layer typified by magnesium fluoride, and an oxide layer typified by molybdenum oxide. In the present invention, the electron injection layer 3e is desirably a very thin layer, and the thickness thereof is preferably in the range of 1 nm to 10 μm, although it depends on the material.

(Hole transport layer 3b)
The hole transport layer 3b is made of a hole transport material having a function of transporting holes, and the hole injection layer 3a and the electron blocking layer are also included in the hole transport layer 3b in a broad sense. The hole transport layer 3b can be provided as a single layer or a plurality of layers.

  The hole transport material has any of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  Although the above-mentioned thing can be used as a positive hole transport material, It is preferable to use a porphyrin compound, an aromatic tertiary amine compound, and a styryl amine compound, especially an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (abbreviation: TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; -Bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ', N'-tetra-p-tolyl-4,4'-diaminobiphenyl; 1,1-bis (4-di-p -Tolylaminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, '-Di (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) c N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N- Diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole and two condensations described in US Pat. No. 5,061,569 Those having an aromatic ring in the molecule, for example, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPD), JP-A-4 3,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which triphenylamine units described in Japanese Patent No. 308688 are linked in three starburst forms ( (Abbreviation: MTDATA).

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  JP-A-11-251067, J. Org. Huang et. al. , Applied Physics Letters, 80 (2002), p. A so-called p-type hole transport material as described in 139 can also be used. In the present invention, it is preferable to use these materials because a light-emitting element with higher efficiency can be obtained.

The hole transport layer 3b is formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. be able to.
Although there is no restriction | limiting in particular about the thickness of the positive hole transport layer 3b, Usually, it exists in the range of 5 nm-5 micrometers, Preferably it exists in the range of 5-200 nm. The hole transport layer 3b may have a single layer structure composed of one or more of the above materials.

  Also, the p-type can be enhanced by doping impurities into the material of the hole transport layer 3b. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  Thus, it is preferable to increase the p property of the hole transport layer 3b because an element with lower power consumption can be manufactured.

[Electron transport layer 3d]
The electron transport layer 3d is made of a material having a function of transporting electrons. In a broad sense, the electron injection layer 3e and a hole blocking layer (not shown) are also included in the electron transport layer 3d. The electron transport layer 3d can be provided as a single layer structure or a multi-layer structure.

As an electron transport material (also serving as a hole blocking material) constituting the layer portion adjacent to the light emitting layer 3c in the electron transport layer 3d having a single layer structure and the electron transport layer 3d having a multilayer structure, electrons injected from the cathode are used. What is necessary is just to have the function to transmit to the light emitting layer 3c.
As such a material, any one of conventionally known compounds can be selected and used. Examples include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane, anthrone derivatives, and oxadiazole derivatives.
Further, in the above oxadiazole derivative, a thiadiazole derivative in which an oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group are also used as the material for the electron transport layer 3d. Can do.
Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (abbreviation: Alq ₃ ), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8- Quinolinol) aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (abbreviation: Znq), etc., and the central metal of these metal complexes A metal complex in which In, Mg, Cu, Ca, Sn, Ga, or Pb is replaced can also be used as the material of the electron transport layer 3d.

In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the material for the electron transport layer 3d.
Further, a distyrylpyrazine derivative exemplified also as a material of the light emitting layer 3c can be used as a material of the electron transport layer 3d, and similarly to the hole injection layer 3a and the hole transport layer 3b, n-type -Si, n An inorganic semiconductor such as type-SiC can also be used as the material of the electron transport layer 3d.

The electron transport layer 3d can be formed by thinning the above material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method.
Although there is no restriction | limiting in particular about the thickness of 3 d of electron carrying layers, Usually, 5 nm-about 5 micrometers, Preferably it exists in the range of 5-200 nm. The electron transport layer 3d may have a single layer structure composed of one or more of the above materials.

In addition, the electron transport layer 3d can be doped with impurities to increase the n property. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.
Furthermore, it is preferable that the electron transport layer 3d contains potassium, a potassium compound, or the like. As the potassium compound, for example, potassium fluoride can be used. Thus, when the n property of the electron carrying layer 3d is made high, the organic EL element of lower power consumption can be produced.

  Further, as the material (electron transporting compound) of the electron transport layer 3d, the same material as that of the intermediate layer 1a described above may be used. The same applies to the electron transport layer 3d that also serves as the electron injection layer 3e, and the same material as that of the intermediate layer 1a described above may be used.

(Blocking layer)
The blocking layer (hole blocking layer, electron blocking layer) is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.

  The hole blocking layer has the function of the electron transport layer 3d in a broad sense. The hole blocking layer is made of a hole blocking material that has a function of transporting electrons but has a very small ability to transport holes, and recombines electrons and holes by blocking holes while transporting electrons. Probability can be improved. Moreover, the structure of the electron carrying layer 3d mentioned later can be used as a hole-blocking layer as needed. The hole blocking layer is preferably provided adjacent to the light emitting layer 3c.

On the other hand, the electron blocking layer has the function of the hole transport layer 3b in a broad sense. The electron blocking layer is made of a material that has the ability to transport holes and has a very small ability to transport electrons. By blocking holes while transporting holes, the probability of recombination of electrons and holes is improved. Can be made.
Moreover, the structure of the positive hole transport layer 3b mentioned later can be used as an electron blocking layer as needed.
The thickness of the hole blocking layer applied to the present invention is preferably in the range of 3 to 100 nm, and more preferably in the range of 5 to 30 nm.

(Auxiliary electrode 15)
The auxiliary electrode 15 is provided for the purpose of reducing the resistance of the transparent electrode 1, and is provided in contact with the conductive layer 1 b of the transparent electrode 1. The material forming the auxiliary electrode 15 is preferably a metal having low resistance such as gold, platinum, silver, copper, or aluminum. Since these metals have low light transmittance, a pattern is formed in a range not affected by extraction of the emitted light h from the light extraction surface 13a.
Examples of the method for forming the auxiliary electrode 15 include a vapor deposition method, a sputtering method, a printing method, an ink jet method, and an aerosol jet method.
The line width of the auxiliary electrode 15 is preferably 50 μm or less from the viewpoint of the aperture ratio for extracting light, and the thickness of the auxiliary electrode 15 is preferably 1 μm or more from the viewpoint of conductivity.

(Encapsulant 17)
The sealing material 17 covers the organic EL element 100 and may be a plate-shaped (film-shaped) sealing member that is fixed to the transparent substrate 13 side by the adhesive 19. It may be a sealing film.
Such a sealing material 17 is provided so as to cover at least the light emitting functional layer 3 in a state where the terminal portions of the transparent electrode 1 and the counter electrode 5a in the organic EL element 100 are exposed. Moreover, an electrode may be provided on the sealing material 17 so that the transparent electrode 1 of the organic EL element 100 and the terminal portions of the counter electrode 5a are electrically connected to this electrode.

Specific examples of the plate-like (film-like) sealing material 17 include a glass substrate, a polymer substrate, a metal substrate, and the like. These substrate materials may be used in the form of a thin film.
Examples of the glass substrate include soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz.
Examples of the polymer substrate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone.
Examples of the metal substrate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.

  Among these, from the viewpoint that the organic EL element can be thinned, a thin film-like polymer substrate or metal substrate can be preferably used as the sealing material.

Furthermore, the polymer substrate in the form of a film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less, JIS K 7129-1992. The water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by a method based on the above is 1 × 10 ⁻³ g / (m ² · 24 h) or less. It is preferable.

  The substrate material as described above may be processed into a concave plate shape and used as the sealing material 17. In this case, the above-described substrate member is subjected to processing such as sand blasting or chemical etching to form a concave shape.

An adhesive 19 for fixing the plate-shaped sealing material 17 to the transparent substrate 13 side seals the organic EL element 100 sandwiched between the sealing material 17 and the transparent substrate 13. It is used as a sealing agent.
Specifically, such an adhesive 19 is a photocuring and thermosetting adhesive having a reactive vinyl group of an acrylic acid-based oligomer, a methacrylic acid-based oligomer, a moisture-curing type such as 2-cyanoacrylic acid ester, or the like. Can be mentioned.

  Moreover, as such an adhesive agent 19, the heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, the organic material which comprises the organic EL element 100 may deteriorate with heat processing. For this reason, the adhesive 19 is preferably one that can be adhesively cured from room temperature to 80 ° C. Further, a desiccant may be dispersed in the adhesive 19.

  Application | coating of the adhesive agent 19 to the adhesion part of the sealing material 17 and the transparent substrate 13 may use a commercially available dispenser, and may print like screen printing.

  In addition, when a gap is formed between the plate-shaped sealing material 17, the transparent substrate 13, and the adhesive 19, in this gap, in the gas phase and the liquid phase, an inert gas such as nitrogen or argon or a fluorine is used. It is preferable to inject an inert liquid such as activated hydrocarbon or silicon oil. A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside.

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.), perchloric acids (eg perchloric acid) Barium, magnesium perchlorate, and the like), and anhydrous salts are preferably used in sulfates, metal halides, and perchloric acids.

  On the other hand, when a sealing film is used as the sealing material 17, the light emitting functional layer 3 in the organic EL element 100 is completely covered and the terminal portions of the transparent electrode 1 and the counter electrode 5a in the organic EL element 100 are exposed. A sealing film is provided on the transparent substrate 13.

Such a sealing film is configured using an inorganic material or an organic material. In particular, it is made of a material having a function of suppressing intrusion of a substance that causes deterioration of the light emitting functional layer 3 in the organic EL element 100 such as moisture and oxygen. As such a material, for example, inorganic materials such as silicon oxide, silicon dioxide, and silicon nitride are used.
Furthermore, in order to improve the brittleness of the sealing film, a laminated structure may be formed using a film made of an organic material in addition to a film made of these inorganic materials.

  The method for forming these films is not particularly limited. For example, vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

(Protective film, protective plate)
Although not shown in the drawings illustrated above, a protective film or a protective plate may be provided between the transparent substrate 13 and the organic EL element 100 and the sealing material 17. This protective film or protective plate is for mechanically protecting the organic EL element 100, and in particular when the sealing material 17 is a sealing film, sufficient mechanical protection is provided for the organic EL element 100. Therefore, it is preferable to provide such a protective film or protective plate.

  As the above protective film or protective plate, a glass plate, a polymer plate, a polymer film thinner than this, a metal plate, a metal film thinner than this, a polymer material film or a metal material film is applied. Among these, it is particularly preferable to use a polymer film because it is light and thin.

[Method for producing organic EL element]
Here, as an example, a method for manufacturing the organic EL element 100 shown in FIG. 2 will be described.

First, on the transparent substrate 13, an intermediate layer 1a made of an organic compound having both the covalent bond site and the coordinate bond site in the molecule is formed to a layer thickness of 1 μm or less, preferably in the range of 10 to 100 nm. A method such as a vapor deposition method is appropriately selected so as to be formed.
Next, a method such as a vapor deposition method so that the conductive layer 1b made of silver (or an alloy containing silver as a main component) has a layer thickness in the range of 5 to 20 nm, preferably in the range of 5 to 8 nm. Is appropriately selected and formed on the intermediate layer 1a to produce the transparent electrode 1 serving as an anode.

Next, the hole injection layer 3a, the hole transport layer 3b, the light emitting layer 3c, the electron transport layer 3d, and the electron injection layer 3e are formed in this order on the transparent electrode 1, thereby forming the light emitting functional layer 3. The formation of each of these layers includes spin coating, casting, ink jet, vapor deposition, and printing. However, vacuum vapor deposition is used because it is easy to obtain a homogeneous film and pinholes are not easily generated. Or a spin coat method is particularly preferable. Further, different formation methods may be applied for each layer.
When employing a vapor deposition method for forming each of these layers, the vapor deposition conditions vary depending on the type of compound used, but generally the boat heating temperature is in the range of 50 to 450 ° C., and the degree of vacuum is 1 × 10 ⁻⁶ to 1 × 10. Each condition is appropriately selected within a range of ⁻² Pa, a deposition rate of 0.01 to 50 nm / second, a substrate temperature of −50 to 300 ° C., and a layer thickness of 0.1 to 5 μm. Is desirable.

After the light emitting functional layer 3 is formed as described above, the counter electrode 5a serving as a cathode is formed thereon by appropriately selecting a film forming method such as a vapor deposition method or a sputtering method. At this time, the counter electrode 5 a is patterned in a shape in which a terminal portion is drawn from the upper side of the light emitting functional layer 3 to the periphery of the transparent substrate 13 while maintaining the insulating state with respect to the transparent electrode 1 by the light emitting functional layer 3. Thereby, the organic EL element 100 is obtained.
Thereafter, a sealing material 17 that covers at least the light emitting functional layer 3 is provided in a state where the terminal portions of the transparent electrode 1 and the counter electrode 5a in the organic EL element 100 are exposed.

  As described above, a desired organic EL element can be produced on the transparent substrate 13. In the production of such an organic EL element 100, it is preferable to consistently produce from the light emitting functional layer 3 to the counter electrode 5a by one evacuation. However, the transparent substrate 13 is taken out from the vacuum atmosphere in the middle and is different. A film forming method may be applied. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  When a DC voltage is applied to the organic EL element 100 thus obtained, the transparent electrode 1 as an anode has a positive polarity, the counter electrode 5a as a cathode has a negative polarity, and the voltage is 2 to 40 V. Luminescence can be observed when applied within the range. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

[Effect of the organic EL element shown in the first example]
The organic EL element 100 described above has a configuration in which the transparent electrode 1 of the present invention having both conductivity and light transmittance is used as an anode, and a light emitting functional layer 3 and a counter electrode 5a serving as a cathode are provided above the transparent electrode 1. is there. For this reason, the extraction efficiency of the emitted light h from the transparent electrode 1 side is improved while applying a sufficient voltage between the transparent electrode 1 and the counter electrode 5a to realize high luminance light emission in the organic EL element 100. Thus, it is possible to increase the luminance. Further, in order to obtain a desired luminance, it is possible to improve the light emission lifetime by reducing the drive voltage.

<< 4. Second Example of Organic EL Device >>
[Configuration of organic EL element]
FIG. 4 is a cross-sectional configuration diagram showing a second example of the organic EL element using the transparent electrode described above as an example of the electronic device of the present invention.
The organic EL element 200 of the second example shown in FIG. 4 is different from the organic EL element 100 of the first example shown in FIG. 3 in that the transparent electrode 1 is used as a cathode. Hereinafter, a detailed description of the same components as in the first example will be omitted, and a characteristic configuration of the organic EL element 200 in the second example will be described below.

  The organic EL element 200 shown in FIG. 4 is provided on the transparent substrate 13, and the transparent electrode 1 of the present invention described above is used as the transparent electrode 1 on the transparent substrate 13 as in the first example. Yes. For this reason, the organic EL element 200 is configured to extract the emitted light h from at least the transparent substrate 13 side. However, the transparent electrode 1 is used as a cathode (cathode), and the counter electrode 5b is used as an anode (anode).

  The layer structure of the organic EL element 200 configured as described above is not limited to the example described below, and may be a general layer structure as in the first example.

  As an example of the layer structure shown in the second example, an electron injection layer 3e / electron transport layer 3d / light emitting layer 3c / hole transport layer 3b / hole injection layer 3a are formed on the transparent electrode 1 functioning as a cathode. The light emitting functional layer 3 laminated in order is illustrated. However, among these, it is an essential condition to have at least the light emitting layer 3c made of an organic material.

  In addition to these layers, the light emitting functional layer 3 can incorporate various functional layers as necessary, as described in the first example. In such a configuration, only the portion where the light emitting functional layer 3 is sandwiched between the transparent electrode 1 and the counter electrode 5b becomes the light emitting region in the organic EL element 200, as in the first example.

  In the layer configuration as described above, the auxiliary electrode 15 may be provided in contact with the conductive layer 1b of the transparent electrode 1 for the purpose of reducing the resistance of the transparent electrode 1. Similar to the example.

Here, the counter electrode 5b used as the anode is composed of a metal, an alloy, an organic or inorganic conductive compound, or a mixture thereof. Specific examples include metals such as gold (Au), oxide semiconductors such as copper iodide (CuI), ITO, ZnO, TiO ₂ , and SnO ₂ .

The counter electrode 5b composed of the materials as described above can be produced by forming a thin film of these conductive materials by a method such as vapor deposition or sputtering.
Further, the sheet resistance value as the counter electrode 5b is preferably several hundred Ω / □ or less, and the film thickness is usually selected within a range of 5 nm to 5 μm, preferably within a range of 5 to 200 nm.

  In addition, when this organic EL element 200 is comprised so that emitted light h can be taken out also from the counter electrode 5b side, as a material which comprises the counter electrode 5b, favorable light transmittance is mentioned among the electrically conductive materials mentioned above. A suitable conductive material is selected and used.

  The organic EL element 200 having the above configuration is sealed with the sealing material 17 in the same manner as in the first example for the purpose of preventing deterioration of the light emitting functional layer 3.

  Of the main layers constituting the organic EL element 200 described above, the detailed structure of the constituent elements other than the counter electrode 5b used as the anode and the method for producing the organic EL element 200 are the same as in the first example. Therefore, detailed description is omitted.

[Effect of organic EL element shown in second example]
In the organic EL element 200 shown in FIG. 4 described above, the transparent electrode 1 of the present invention having both conductivity and light transmittance is used as a cathode, and the light emitting functional layer 3 and the counter electrode 5b serving as the anode are formed on the upper portion. This is a configuration provided. For this reason, as in the first example, a sufficient voltage is applied between the transparent electrode 1 and the counter electrode 5b to realize high-luminance light emission in the organic EL element 200, and light emitted from the transparent electrode 1 side. It is possible to increase the luminance by improving the extraction efficiency of h. Further, it is possible to improve the light emission life by reducing the drive voltage for obtaining a predetermined luminance.

<< 5. Third Example of Organic EL Device >>
[Configuration of organic EL element]
FIG. 5 is a cross-sectional configuration diagram illustrating a third example of the organic EL element using the transparent electrode described above as an example of the electronic device of the present invention.
The organic EL element 300 of the third example shown in FIG. 5 is different from the organic EL element 100 of the first example described with reference to FIG. 3 in that a counter electrode 5c is provided on the substrate 131 side, and a light emitting functional layer is formed thereon. 3 and the transparent electrode 1 are stacked in this order. Hereinafter, the detailed description of the same components as those in the first example will be omitted, and the characteristic configuration of the organic EL element 300 in the third example will be described.

  The organic EL element 300 shown in FIG. 5 is provided on a substrate 131, and the counter electrode 5c serving as an anode, the light emitting functional layer 3, and the transparent electrode 1 serving as a cathode are laminated in this order from the substrate 131 side. . Among these, as the transparent electrode 1, the transparent electrode 1 of the present invention described above is used. For this reason, the organic EL element 300 is configured to extract the emitted light h from at least the transparent electrode 1 side opposite to the substrate 131.

  The layer structure of the organic EL element 300 configured as described above is not limited to the example described below, and may be a general layer structure as in the first example. As an example in the case of the third example, as shown in FIG. 5, a hole injection layer 3a / a hole transport layer 3b / a light emitting layer 3c / an electron transport layer 3d are formed on the counter electrode 5c functioning as an anode. The structure laminated | stacked in order is illustrated. However, it is essential to have at least the light emitting layer 3c configured using an organic material. The electron transport layer 3d also serves as the electron injection layer 3e, and is provided as an electron transport layer 3d having electron injection properties.

  In particular, a characteristic configuration of the organic EL element 300 shown as the third example is that an electron transporting layer 3d having an electron injecting property is provided as the intermediate layer 1a in the transparent electrode 1. That is, in the third example, the transparent electrode 1 used as a cathode is composed of an intermediate layer 1a also serving as an electron transport layer 3d having electron injection properties, and a conductive layer 1b provided on the intermediate layer 1a. It is.

  Such an electron transport layer 3d is configured by using the material constituting the intermediate layer 1a of the transparent electrode 1 described above.

  In addition to these layers, the light emitting functional layer 3 can employ various functional layers as necessary, as described in the first example, but the intermediate layer 1a of the transparent electrode 1 can be used. The electron injection layer and the hole blocking layer are not provided between the electron transport layer 3d serving also as the conductive layer 1b and the conductive layer 1b of the transparent electrode 1. In the configuration as described above, only the portion where the light emitting functional layer 3 is sandwiched between the transparent electrode 1 and the counter electrode 5c becomes the light emitting region in the organic EL element 300, as in the first example.

  In the layer structure as described above, the auxiliary electrode 15 may be provided in contact with the conductive layer 1b of the transparent electrode 1 for the purpose of reducing the resistance of the transparent electrode 1. The same as in the example.

Furthermore, the counter electrode 5c used as the anode is composed of a metal, an alloy, an organic or inorganic conductive compound, or a mixture thereof. Specific examples include metals such as gold (Au), oxide semiconductors such as copper iodide (CuI), ITO, ZnO, TiO ₂ , and SnO ₂ .

The counter electrode 5c made of the material as described above can be produced by forming a thin film of these conductive materials by a method such as vapor deposition or sputtering.
Further, the sheet resistance value as the counter electrode 5c is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 5 nm to 5 μm, preferably 5 to 200 nm.

  In addition, when this organic EL element 300 is comprised so that the emitted light h can be taken out also from the counter electrode 5c side, as a material which comprises the counter electrode 5c, light transmittance is favorable among the electrically conductive materials mentioned above. A suitable conductive material is selected and used. In this case, the substrate 131 is the same as the transparent substrate 13 described in the first example, and the surface facing the outside of the substrate 131 may be the light extraction surface 131a.

[Effect of organic EL element shown in third example]
In the organic EL element 300 shown in the third example described above, the electron transporting layer 3d having the electron injecting property constituting the uppermost part of the light emitting functional layer 3 is used as the intermediate layer 1a, and the conductive layer 1b is provided thereon. The transparent electrode 1 comprising the intermediate layer 1a and the upper conductive layer 1b is provided as a cathode. Therefore, similarly to the first example and the second example, a sufficient voltage is applied between the transparent electrode 1 and the counter electrode 5c to realize high-luminance light emission in the organic EL element 300, while the transparent electrode 1 side. It is possible to increase the luminance by improving the extraction efficiency of the emitted light h from the light source. Further, it is possible to improve the light emission life by reducing the drive voltage for obtaining a predetermined luminance. Further, when the counter electrode 5c is made of a light-transmissive electrode material, the emitted light h can be extracted from the counter electrode 5c.

  In the third example described above, the intermediate layer 1a of the transparent electrode 1 has been described as also serving as the electron transport layer 3d having electron injection properties. However, in the present invention, the configuration is not limited to these examples. The intermediate layer 1a may also serve as the electron transport layer 3d that does not have electron injecting property, or the intermediate layer 1a may serve as the electron injection layer instead of the electron transport layer. Also good. In addition, the intermediate layer 1a may be formed as an extremely thin film that does not affect the light emitting function of the organic EL element. In this case, the intermediate layer 1a has electron transport properties and electron injection properties. Not.

  Furthermore, when the intermediate layer 1a of the transparent electrode 1 is formed as an ultrathin film that does not affect the light emitting function of the organic EL element, the counter electrode on the substrate 131 side is used as a cathode, and the light emitting functional layer 3 is formed. The transparent electrode 1 may be an anode. In this case, the light emitting functional layer 3 is formed in order from the counter electrode 5c (cathode) side on the substrate 131, for example, electron injection layer 3e / electron transport layer 3d / light emitting layer 3c / hole transport layer 3b / hole injection layer 3a. Are stacked. A transparent electrode 1 having a laminated structure of an extremely thin intermediate layer 1a and a conductive layer 1b is provided as an anode on the top.

<< 6. Applications of organic EL devices >>
Since the organic EL element which consists of each structure demonstrated with the said figure is a surface light emitter as mentioned above, it can be applied as various light emission sources. For example, lighting devices such as home lighting and interior lighting, backlights for watches and liquid crystal display devices, lighting for billboard advertisements, light sources for traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, optical communication processors Examples include, but are not limited to, a light source and a light source of an optical sensor. In particular, the light source can be effectively used as a backlight of a liquid crystal display device combined with a color filter and an illumination light source.

  Further, the organic EL element of the present invention may be used as a kind of lamp for illumination or exposure light source, a projection apparatus for projecting an image, or a type for directly viewing a still image or a moving image. It may be used as a display device (display). In this case, with the recent increase in the size of lighting devices and displays, the light emitting surface may be enlarged by so-called tiling, in which light emitting panels provided with organic EL elements are joined together in a plane.

  The driving method when used as a display device for moving image reproduction may be either a simple matrix (passive matrix) method or an active matrix method. In addition, a color or full-color display device can be manufactured by using two or more organic EL elements of the present invention having different emission colors.

  Hereinafter, a lighting device will be described as an example of the application, and then a lighting device in which the light emitting surface is enlarged by tiling will be described.

<< 7. Illumination device-1 >>
The lighting device according to the present invention can include the organic EL element of the present invention.

  The organic EL element used in the lighting device according to the present invention may be designed such that each organic EL element having the above-described configuration has a resonator structure. The purpose of use of the organic EL element configured to have a resonator structure includes a light source of an optical storage medium, a light source of an electrophotographic copying machine, a light source of an optical communication processor, a light source of an optical sensor, etc. It is not limited to. Moreover, you may use for the said use by making a laser oscillation.

  In addition, the material used for the organic EL element of this invention is applicable to the organic EL element (it is also called white organic EL element) which produces substantially white light emission. For example, a plurality of light emitting materials can simultaneously emit a plurality of light emission colors to obtain white light emission by color mixing. The combination of a plurality of emission colors may include three emission maximum wavelengths of the three primary colors of red, green, and blue, or two of the complementary colors such as blue and yellow, blue green and orange, etc. The thing containing the light emission maximum wavelength may be used.

  In addition, a combination of light emitting materials for obtaining a plurality of emission colors is a combination of a plurality of phosphorescent or fluorescent materials, a light emitting material that emits fluorescence or phosphorescence, and excitation of light from the light emitting materials. Any combination with a pigment material that emits light as light may be used, but in a white organic EL element, a combination of a plurality of light-emitting dopants may be used.

  Such a white organic EL element is different from a configuration in which organic EL elements each emitting light are individually arranged in parallel in an array to obtain white light emission, and the organic EL element itself emits white light. For this reason, a mask is not required for the formation of most layers constituting the element, and for example, an electrode film can be formed on one surface by vapor deposition, casting, spin coating, ink jet, printing, etc., and productivity is improved. .

  Moreover, there is no restriction | limiting in particular as a light emitting material used for the light emitting layer of such a white organic EL element, For example, if it is a backlight in a liquid crystal display element, it will fit in the wavelength range corresponding to CF (color filter) characteristic. As described above, any metal complex according to the present invention or a known light emitting material may be selected and combined to be whitened.

  If the white organic EL element demonstrated above is used, it is possible to produce the illuminating device which produces substantially white light emission.

<< 8. Illumination device-2 >>
FIG. 6 shows a cross-sectional configuration diagram of a lighting device in which a plurality of organic EL elements having the above-described configurations are used to increase the light emitting surface area.
The lighting device 21 shown in FIG. 6 has a large light emitting surface by, for example, arranging a plurality of light emitting panels 22 provided with the organic EL elements 100 on the transparent substrate 13 on the support substrate 23 (that is, tiling). It is the structure which made the area. The support substrate 23 may also serve as a sealing material, and each light-emitting panel 22 is tied with the organic EL element 100 sandwiched between the support substrate 23 and the transparent substrate 13 of the light-emitting panel 22. Ring. An adhesive 19 may be filled between the support substrate 23 and the transparent substrate 13, thereby sealing the organic EL element 100.
In addition, the edge part of the transparent electrode 1 which is an anode, and the counter electrode 5a which is a cathode are exposed around the light emission panel 21. FIG. However, only the exposed portion of the counter electrode 5a is shown in the drawing.
Moreover, in FIG. 6, as the light emission functional layer 3 which comprises the organic EL element 100, on the transparent electrode 1, hole injection layer 3a / hole transport layer 3b / light emission layer 3c / electron transport layer 3d / electron injection layer A configuration in which 3e is sequentially laminated is shown as an example.

  In the lighting device 21 having the configuration shown in FIG. 6, the center of each light emitting panel 22 is a light emitting area A, and a non-light emitting area B is generated between the light emitting panels 22. For this reason, a light extraction member for increasing the light extraction amount from the non-light emitting region B may be provided in the non-light emitting region B of the light extraction surface 13a. As the light extraction member, a light collecting sheet or a light diffusion sheet can be used.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented.

Example 1
<< Preparation of transparent electrode >>
According to the method shown below, the transparent electrodes 1 to 20 were produced so that the area of the conductive region was 5 cm × 5 cm. The transparent electrodes 1 to 4 were produced as single layer transparent electrodes, and the transparent electrodes 5 to 20 were produced as transparent electrodes having a laminated structure of an intermediate layer and a conductive layer.

[Preparation of transparent electrode 1]
A transparent electrode 1 of a comparative example having a single layer structure was produced according to the method shown below.

A transparent non-alkali glass substrate was fixed to a substrate holder of a commercially available vacuum deposition apparatus, and this was attached to a vacuum tank of the vacuum deposition apparatus. On the other hand, a resistance heating boat made of tungsten was filled with silver (Ag) and mounted in the vacuum chamber. Next, after depressurizing the inside of the vacuum chamber to 4 × 10 ⁻⁴ Pa, the resistance heating boat is energized and heated, and is made of silver on the base material within a deposition rate range of 0.1 to 0.2 nm / second. A single electrode of a conductive layer having a thickness of 5 μm was deposited to prepare the transparent electrode 1.

[Preparation of transparent electrodes 2 to 4]
In the production of the transparent electrode 1, transparent electrodes 2 to 4 were produced in the same manner except that the thickness of the conductive layer was changed to 8 nm, 10 nm, and 15 nm, respectively.

[Preparation of transparent electrode 5]
On a transparent base made of alkali-free glass, Alq ₃ having the following structure is formed as an intermediate layer having a thickness of 25 nm by a sputtering method, and an upper portion thereof is used to form a conductive layer in the production of the transparent electrode 1. A transparent electrode 5 was produced by vapor-depositing a conductive layer made of silver (Ag) having a thickness of 8 nm by the same method (vacuum vapor deposition method) as used.

[Preparation of transparent electrode 6]
A transparent non-alkali glass base material is fixed to a base material holder of a commercially available vacuum deposition apparatus, and ET-1 having a structure shown below is filled in a resistance heating boat made of tantalum. It attached to the 1st vacuum chamber of a vacuum evaporation system. Moreover, silver (Ag) was put into the resistance heating boat made from tungsten, and it attached in the 2nd vacuum chamber.

Next, after reducing the pressure in the first vacuum tank to 4 × 10 ⁻⁴ Pa, the heating boat containing ET-1 was energized and heated, and the substrate was within a deposition rate range of 0.1 to 0.2 nm / second. An intermediate layer made of ET-1 having a thickness of 25 nm was formed by evaporation.

Next, the base material on which the intermediate layer is formed is transferred to the second vacuum tank while being in a vacuum state, and after the second vacuum tank is depressurized to 4 × 10 ⁻⁴ Pa, the heating boat containing silver is energized and heated, A conductive layer made of silver having a thickness of 8 nm was vapor-deposited at a deposition rate of 0.1 to 0.2 nm / second to obtain a transparent electrode 6 in which an intermediate layer and a conductive layer made of silver were laminated thereon. .

[Preparation of transparent electrodes 7 and 8]
In the production of the transparent electrode 6, transparent electrodes 7 and 8 were produced in the same manner except that the type of the intermediate layer forming material was changed from ET-1 to ET-2 and ET-3 having the structure shown below.

[Preparation of transparent electrodes 9 to 49]
In the production of the transparent electrode 6, the type of the material for forming the intermediate layer (the compound (1) to the compound (38)) and the thickness of the silver layer in the conductive layer were set to the conditions described in Tables 1 to 3, respectively. Transparent electrodes 9 to 49 were produced in the same manner except that the change was made.

[Preparation of transparent electrodes 50 and 51]
Transparent electrodes 50 and 51 were produced in the same manner as in the production of the transparent electrodes 31 and 32 except that the type of the base material was changed from non-alkali glass to PET (polyethylene terephthalate).

[Preparation of transparent electrode 52]
A transparent non-alkali glass base material is fixed to a base material holder of a commercially available vacuum deposition apparatus, compound (6) is filled in a resistance heating boat made of tantalum, and these substrate holder and heating boat are connected to the vacuum deposition apparatus. Attached to the first vacuum chamber. Moreover, silver (Ag) was put into the resistance heating boat made from tungsten, and it attached in the 2nd vacuum chamber.

Next, after reducing the pressure of the first vacuum tank to 4 × 10 ⁻⁴ Pa, the heating boat containing the compound (6) was heated by energization, and the deposition rate was within a range of 0.1 to 0.2 nm / second. It vapor-deposited on the material and the intermediate | middle layer 1a which consists of a compound (6) with a thickness of 25 nm was formed.

Next, the base material on which the intermediate layer is formed is transferred to the second vacuum tank while being in a vacuum state, and after the second vacuum tank is depressurized to 4 × 10 ⁻⁴ Pa, the heating boat containing silver is energized and heated, A conductive layer 1b made of silver having a thickness of 8 nm was deposited at a deposition rate of 0.1 to 0.2 nm / second.

Next, the base material on which the conductive layer is formed is transferred to the first vacuum chamber in a vacuum state, and the first vacuum chamber is depressurized to 44 × 10 ⁻⁴ Pa, and then the heating boat containing the compound (6) is energized. Then, the intermediate layer 1c made of the compound (6) having a thickness of 15 nm was formed by vapor deposition on the base material at a deposition rate of 0.1 to 0.2 nm / second.
A transparent electrode 52 was obtained in which a conductive layer 1b made of silver was laminated on top of an intermediate layer 1a made of compound (6), and further an intermediate layer 1c made of compound (6) was laminated on top of this.

[Production of transparent electrodes 53 to 63]
In the production of the transparent electrode 52, transparent electrodes 53 to 63 were produced in the same manner except that the forming materials of the intermediate layers 1a and 1c were changed to the compounds shown in Table 3, respectively.

<< Evaluation of transparent electrode >>
About the produced said transparent electrodes 1-63, according to the following method, the light transmittance, the sheet resistance value, and the high temperature and high humidity preservability (electrode life under high temperature and high humidity preservation) were measured.

(Measurement of light transmittance)
About each produced said transparent electrode, the light transmittance (%) in wavelength 550nm was measured using the base material used for preparation of each transparent electrode using the spectrophotometer (Hitachi Ltd. U-3300).

[Measurement of sheet resistance]
About each produced said transparent electrode, the sheet resistance value (ohm / square) was measured by the 4-terminal 4 probe method constant current application system using the resistivity meter (MCP-T610 by Mitsubishi Chemical Corporation).

[High temperature and high humidity storage stability (electrode life under high temperature and high humidity storage)]
About each produced said transparent electrode, it preserve | saves in a high temperature, high humidity environment (temperature 60 degreeC, humidity 90%), records the time until it measures and measures the sheet resistance value in time, High humidity storage stability. The high-temperature and high-humidity storage stability is expressed as a relative value when the transparent electrode 8 (when the material ET-3 of the intermediate layer 1a is used) is set to 100.

  The results obtained as described above are shown in Tables 1 to 3.

As is clear from the results described in Tables 1 to 3, silver (Ag) is formed on an intermediate layer formed using an organic compound having both silver, a covalent bond site, and a coordinate bond site in the molecule. Each of the transparent electrodes 9 to 51 of the present invention provided with the conductive layer as the main component has a light transmittance of 52% or more and a sheet resistance value of 11.5Ω / □ or less. Moreover, the high temperature / high humidity storage stability is as high as 250 or more.
This is because the intermediate layer is formed by using an organic compound having both silver, a covalent bond site and a coordinate bond site in the molecule, thereby suppressing aggregation of the silver film formed thereon and generation of mottle. Even if a silver film having a certain thickness is formed, aggregation of silver is suppressed, and both high light transmission, reduction of sheet resistance value, and long life under high temperature and high humidity storage are achieved. I was able to.
Furthermore, it was confirmed that more preferable results can be obtained even in the transparent electrodes 52 to 63 having a configuration in which the conductive layer is sandwiched between two intermediate layers.

On the other hand, in the transparent electrodes 1 to 4 of the comparative example having no intermediate layer, although the sheet resistance value decreases as the thickness of the conductive layer that is a silver layer is increased, the conductive layer is formed. Decrease in light transmittance due to silver aggregation (motor) at the time becomes remarkable, and it is impossible to achieve both light transmittance and sheet resistance value. Furthermore, the high temperature / high humidity storage property was very low at 32 or less.
Moreover, even in the transparent electrodes 5 to 8 using Alq ₃ and ET-1 to ET- ₃ as the intermediate layer, the light transmittance was low and the sheet resistance value could not be lowered to a desired condition. Furthermore, the high temperature / high humidity storage property was as low as 100 or less.

Example 2
<Production of light emitting panel>
[Preparation of light-emitting panel 1]
Using the transparent electrode 1 produced in Example 1 as an anode, a double-sided light emitting panel 1 having the configuration shown in FIG. 7 (but not including the intermediate layer 1a) was produced according to the following procedure.

  First, the transparent substrate 13 having the transparent electrode 1 formed only with the conductive layer 1b produced in Example 1 is fixed to a substrate holder of a commercially available vacuum deposition apparatus, and the transparent electrode 1 (only the conductive layer 1b) is formed. A vapor deposition mask was placed opposite to the surface side. Moreover, each material which comprises the light emission functional layer 3 was filled with the optimal quantity for formation of each layer to each heating boat in a vacuum evaporation system. In addition, as a heating boat, what was produced with the resistance heating material made from tungsten was used.

Next, the vapor deposition chamber of the vacuum vapor deposition apparatus is depressurized to a vacuum degree of 4 × 10 ⁻⁴ Pa, and each layer constituting the light emitting functional layer 3 shown below is heated by sequentially energizing and heating a heating boat containing each material. Formed.

  First, a hole-transporting / injecting layer which serves as both a hole-injecting layer and a hole-transporting layer made of α-NPD by energizing and heating a heating boat containing α-NPD shown below as a hole-transporting injecting material 31 was formed on the conductive layer 1 b constituting the transparent electrode 1. At this time, the vapor deposition rate was in the range of 0.1 to 0.2 nm / second, and the vapor deposition was performed under the condition that the layer thickness was 20 nm.

  Next, a heating boat containing Exemplified Compound H4 as a host compound and a heating boat containing Exemplified Compound Ir-4 as a phosphorescent compound were energized independently, and Exemplified Compound H4 as a host compound and Phosphorus A light-emitting layer 3 c composed of Illustrative Compound Ir-4, which is a photoluminescent compound, was formed on the hole transport / injection layer 31. At this time, under the condition that the deposition rate (nm / second) is Exemplified Compound H4: Exemplified Compound Ir-4 = 100: 6, the current-carrying conditions of the heating boat are adjusted as appropriate so that the thickness of the light emitting layer becomes 30 nm. I made it.

  Next, a heating boat containing BAlq shown below as a hole blocking material was energized and heated to form a hole blocking layer 33 made of BAlq on the light emitting layer 3c. At this time, vapor deposition was performed under the conditions of a deposition rate of 0.1 to 0.2 nm / second and a thickness of 10 nm.

  Thereafter, a heating boat containing ET-4 shown below as an electron transporting material and a heating boat containing potassium fluoride are energized independently, and an electron transport layer composed of ET-4 and potassium fluoride. 3d was formed on the hole blocking layer 33. At this time, under the condition that the deposition rate (nm / second) is ET-4: potassium fluoride = 75: 25, the current-carrying conditions of the heating boat are appropriately adjusted so that the thickness of the electron transport layer 3d is 30 nm. And deposited.

  Next, a heating boat containing potassium fluoride as an electron injection material was energized and heated to form an electron injection layer 3e made of potassium fluoride on the electron transport layer 3d. At this time, vapor deposition was performed at a vapor deposition rate of 0.01 to 0.02 nm / second so as to have a layer thickness of 1 nm.

  Thereafter, the transparent substrate 13 formed up to the electron injection layer 3e was transferred from the vapor deposition chamber of the vacuum vapor deposition apparatus to the processing chamber of the sputtering apparatus to which an ITO target as a counter electrode material was attached while maintaining the vacuum state. Next, in the processing chamber, a light-transmitting counter electrode 5a made of ITO having a film thickness of 150 nm was formed as a cathode at a film formation rate of 0.3 to 0.5 nm / second.

  As described above, the organic EL element 400 was formed on the transparent substrate 13.

  Next, the organic EL element 400 is covered with a sealing material 17 made of a glass substrate having a thickness of 300 μm, and the adhesive 19 (sealing material) is interposed between the sealing material 17 and the transparent substrate 13 so as to surround the organic EL element 400. ). As the adhesive 19, an epoxy photocurable adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) was used. The adhesive 19 filled between the sealing material 17 and the transparent substrate 13 is irradiated with UV light from the glass substrate (sealing material 17) side to cure the adhesive 19 and seal the organic EL element 400. Stopped.

  In forming the organic EL element 400, an evaporation mask is used for forming each layer, and the central 4.5 cm × 4.5 cm of the 5 cm × 5 cm transparent substrate 13 is defined as the light emitting region A, and the entire circumference of the light emitting region A is formed. A non-light emitting region B having a width of 0.25 cm was provided. The transparent electrode 1 serving as the anode and the counter electrode 5a serving as the cathode are insulated from each other by the light-emitting functional layer 3 from the hole transport / injection layer 31 to the electron injection layer 35 and are connected to the periphery of the transparent substrate 13. The part was formed in a drawn shape.

  As described above, the light-emitting panel 1 in which the organic EL element 400 was provided on the transparent substrate 13 and sealed with the sealing material 17 and the adhesive 19 was manufactured. In this light emitting panel 1, the light emission h of each color generated in the light emitting layer 3c is extracted from both the transparent electrode 1 side, that is, the transparent substrate 13 side, and the counter electrode 5a side, that is, the sealing material 17 side. It has become.

[Production of light emitting panels 2 to 63]
In the production of the light-emitting panel 1, light-emitting panels 2 to 63 were produced in the same manner except that the transparent electrodes 2 to 63 produced in Example 1 were used in place of the transparent electrode 1, respectively.

<Evaluation of luminous panel>
About the produced said light emission panels 1-63, the light transmittance and the drive voltage were measured in accordance with the following method.

(Measurement of light transmittance)
About each produced said light emission panel, the light transmittance (%) in wavelength 550nm was measured using the base material used for preparation of each transparent electrode using the spectrophotometer (Hitachi U-3300).

[Measurement of drive voltage]
The front luminance is measured on both sides of the transparent electrode 1 side (that is, the transparent substrate 13 side) and the counter electrode 5a side (that is, the sealing material 17 side) of each of the produced light emitting panels, and the sum is 1000 cd / m ^2. Was measured as a drive voltage (V). For the measurement of luminance, a spectral radiance meter CS-1000 (manufactured by Konica Minolta) was used. It represents that it is so preferable that the numerical value of the obtained drive voltage is small.

[Change of rectification ratio under constant current]
The rectification ratio was measured for the transparent electrode 1 side (that is, the transparent substrate 13 side) of each of the produced light emitting panels. Here, the current value when a drive voltage of +2.5 V is applied in the forward direction and the current value when a drive voltage of −2.5 V is applied in the reverse direction are measured, and [current value (+2.5 V) / Current value (−2.5 V)] was calculated as a rectification ratio.

  The results obtained as described above are shown in Tables 4 and 5.

As is clear from the results shown in Tables 4 and 5, the light-emitting panels 9 to 63 of the present invention using the transparent electrode 1 of the present invention as the anode of the organic EL element each have a light transmittance of 51% or more. Yes, and the drive voltage is suppressed to 3.7 V or less. Furthermore, the rectification ratio change under a constant current is suppressed to 25 or less.
On the other hand, the light-emitting panels 1 to 8 using the transparent electrode of the comparative example as the anode of the organic EL element all have a light transmittance of less than 48%, and do not emit light even when a voltage is applied, Or even if it emitted light, the drive voltage was as high as 5.0V. Furthermore, the rectification ratio change under a constant current was very large.

  As a result, the light-emitting panel including the organic EL element of the present invention using the transparent electrode having the configuration defined in the present invention has excellent light transmittance, low driving voltage, and change in rectification ratio under a constant current. It can be seen that can be reduced.

DESCRIPTION OF SYMBOLS 1 Transparent electrode 1a Intermediate | middle layer 1b Conductive layer 3 Light emission functional layer 3a Hole injection layer 3b Hole transport layer 3c Light emission layer 3d Electron transport layer 3e Electron injection layer 5a, 5b, 5c Counter electrode 11 Base material 13 Transparent substrate (base) Material)
13a Light extraction surface 15 Auxiliary electrode 17 Sealant 19 Adhesive 22 Light-emitting panel 23 Support substrate 100, 200, 300, 400 Organic EL element 131 Substrate 131a Light extraction surface A Light-emitting region B Non-light-emitting region h Light-emitting light

Claims (8)

A transparent electrode comprising a conductive layer and an intermediate layer provided adjacent to the conductive layer,
The transparent electrode has a light transmittance of 50% or more at a wavelength of 550 nm and a sheet resistance value of 20Ω / □ or less,
The intermediate layer contains an organic compound having both a covalent bond site capable of covalently bonding to silver and a coordinate bond site capable of coordinating with silver in the molecule,
The conductive electrode is a vapor-deposited film containing silver as a main component.   2. The transparent electrode according to claim 1, wherein the coordination bond site is a nitrogen atom contained in an aromatic heterocycle and is not involved in aromaticity. The transparent electrode according to claim 1, wherein the covalent bond site is represented by the following general formula (1) or the following general formula (2).
General formula (1): -SH
Formula (2): —S—S—R
[In the above general formula (2), R represents a substituent. ]   4. The transparent electrode according to claim 1, wherein the number of the coordination binding sites in the molecule is larger than the number of the covalent binding sites. 5. The transparent electrode according to any one of claims 1 to 4, wherein the molecular weight of the organic compound is 1200 or less. A second intermediate layer adjacent to the conductive layer and facing the intermediate layer;
The transparent electrode of any one of claims 1 to 5, wherein said conductive layer said an intermediate layer and configurations sandwiched by said second intermediate layer. An electronic device comprising the transparent electrode according to any one of claims 1 to 6 . An organic electroluminescence device comprising the transparent electrode according to any one of claims 1 to 6 .

Images