JP5888096B2 - Display device - Google Patents

Description

  The present invention relates to a display device, and more particularly, to a display device using an organic electroluminescent element having a tandem structure in which a plurality of light emitting units each having a light emitting layer formed using an organic material are stacked.

  An organic electroluminescent element (so-called organic EL element) using electroluminescence (hereinafter referred to as EL) of an organic material is a thin-film type completely solid element capable of emitting light at a low voltage of several V to several tens V. It has many excellent features such as high brightness, high luminous efficiency, thinness, and light weight. A display device using such an organic electroluminescent element is notable for being thin and lightweight, and has attracted attention as being capable of realizing a display device having flexible flexibility.

In recent years, a display device using such an organic electroluminescent element has a configuration in which an organic electroluminescent element having a tandem structure in which light emitting units of a plurality of colors are stacked is aimed at miniaturization of pixels. Proposed. In this case, it is necessary to dispose an intermediate electrode for controlling light emission in each light emitting unit between the light emitting units, and this intermediate electrode is required to have light transmittance with suppressed absorption of emitted light. As such an intermediate electrode, a metal layer having a small work function such as Mg, Mg / Ag, and arsenic (As), and indium tin oxide (SnO ₂ —In ₂ O ₃ : Indium Tin Oxide: ITO) A laminate is disclosed (see Patent Document 1 below).

Japanese Patent No. 3496681

  However, an intermediate electrode composed of a laminated structure of a metal layer and ITO is difficult to achieve both sufficient electrical conductivity and light transmission, which causes a decrease in color reproducibility in a display device. ing.

  Accordingly, the present invention provides a display device with excellent color reproducibility by using an intermediate electrode that has both sufficient conductivity and light transmission, thereby providing excellent color tone controllability in a tandem organic electroluminescent device. The purpose is to provide.

  The above object of the present invention is achieved by the following configurations.

1. A pair of electrodes;
A plurality of light emitting units each having a light emitting layer of a different light emission color configured using an organic material, and arranged in an overlapping manner between the electrodes;
Composed of silver or a silver-based alloy, and a transparent conductive layer disposed between the light emitting units;
Composed of a compound containing nitrogen atoms, and a nitrogen-containing layer disposed adjacent to the transparent conductive layer;
A display device comprising:

2. The display device according to 1, wherein the compound constituting the nitrogen-containing layer has an effective action energy ΔEef with silver represented by the following formula (1) satisfying the following formula (2).

3. The display device according to 1 or 2, wherein the compound includes a compound represented by the following general formula (1).
[In General Formula (1), Y5 represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof.
E51 to E66 and E71 to E88 each represent -C (R3) = or -N =, and R3 represents a hydrogen atom or a substituent.
At least one of E71 to E79 and at least one of E80 to E88 represent -N =. n3 and n4 represent an integer of 0 to 4, but n3 + n4 is an integer of 2 or more. ]

4). The display device according to 1 or 2, wherein the compound includes a compound represented by the following general formula (2).
[However, in General Formula (2), at least one of T11 and T12 is a nitrogen atom, at least one of T21 to T25 is a nitrogen atom, and at least one of T31 to T35 is a nitrogen atom. .
R represents a substituent. ]

5. The display according to any one of 1 to 4, wherein the plurality of light emitting units are a light emitting unit that obtains blue emitted light, a light emitting unit that obtains green emitted light, and a light emitting unit that obtains red emitted light. apparatus.

6). One of the pair of electrodes is configured as a transparent electrode on the light extraction side,
The display device according to any one of 1 to 5, wherein the plurality of light emitting units has a shorter emission wavelength as being arranged closer to the light extraction side.

7). One of the pair of electrodes is configured as a plurality of electrode patterns extending in one direction,
Each of the other of the pair of electrodes and the transparent conductive layer is configured as a plurality of electrode patterns extending in the other direction intersecting the one direction,
The display device according to any one of 1 to 6, wherein the light emitting unit is formed as a continuous film between the pair of electrodes and the transparent conductive layer.

8). One of the pair of electrodes and the transparent conductive layer are configured as a plurality of pixel electrodes,
The other of the pair of electrodes is disposed to be opposed to the plurality of pixel electrodes as a common electrode,
The display device according to any one of 1 to 6, wherein the light emitting unit is formed as a continuous film between the plurality of pixel electrodes and the common electrode.

  In the display device of the present invention configured as described above, a transparent conductive layer composed of silver or an alloy containing silver as a main component and a nitrogen-containing layer adjacent thereto are sandwiched between light emitting units. It is a configuration. Here, in the transparent conductive layer adjacent to the nitrogen-containing layer, the silver atoms constituting this interact with the nitrogen atoms constituting the nitrogen-containing layer, the diffusion distance on the surface of the nitrogen-containing layer is reduced, and silver aggregation occurs. It will be suppressed. For this reason, the transparent conductive layer is generally a single-layer growth type (Frank-van der Merwe: FW) which is easily isolated in an island shape by film growth of a nuclear growth type (Volume-Weber: VW type). The film is formed by the film growth of the mold, thereby forming a thin film having a uniform film thickness. Therefore, between the light emitting units, a transparent conductive layer in which conductivity is secured while sandwiching the light transmittance with a thinner film thickness is sandwiched.

  As a result, by using the transparent conductive layer as an intermediate electrode, it is possible to prevent absorption of emitted light in the transparent conductive layer while controlling light emission in the plurality of light emitting units with high accuracy.

  As described above, according to the present invention, it is possible to prevent the absorption of the emitted light in the transparent conductive layer while controlling the light emission in the plurality of light emitting units with high accuracy. Color tone controllability is improved without reducing the light extraction efficiency from each light emitting unit stacked in the organic electroluminescent element, and as a result, the brightness and color reproducibility of the display device using this organic electroluminescent element is improved. Can be achieved.

It is a cross-sectional schematic diagram which shows the structure of the transparent conductive layer used for the display apparatus of embodiment. It is a cross-sectional schematic diagram of the principal part for demonstrating the structure of the organic electroluminescent element of the tandem structure used for the display apparatus of embodiment. It is a plane schematic diagram for demonstrating the structure of the passive matrix type display apparatus using an organic electroluminescent element. It is a cross-sectional schematic diagram for 3 pixels in the display apparatus of FIG. It is a plane schematic diagram for demonstrating the structure of the active matrix type display apparatus using an organic electroluminescent element. It is a cross-sectional schematic diagram for 3 pixels in the display apparatus of FIG. It is a cross-sectional schematic diagram for 3 pixels for demonstrating the structure of the other active matrix type display apparatus using an organic electroluminescent element. It is a graph which shows the relationship between effective action energy (DELTA) Eef and sheet resistance in the transparent electrode produced in the Example.

Hereinafter, embodiments of the present invention will be described in the following order based on the drawings.
1. 1. Configuration of transparent conductive layer used in display device 2. Configuration of organic electroluminescent element used in display device 3. Passive matrix type display device using organic electroluminescence device. 4. Active matrix display device using organic electroluminescence device 5. Other active matrix type display devices using organic electroluminescent elements Modification 1
7). Modification 2

<< 1. Configuration of transparent conductive layer used in display device >>
FIG. 1 is a schematic cross-sectional view showing a configuration of a transparent conductive layer used in an organic electroluminescent device having a tandem structure. As shown in this figure, the transparent conductive layer 1b is characterized by being provided adjacent to the nitrogen-containing layer 1a. The transparent conductive layer 1b is made of silver (Ag) or an alloy containing silver as a main component. The nitrogen-containing layer 1a is composed of a compound containing a nitrogen atom, and the effective action energy ΔEef described below has a specific relationship with silver, which is the main material constituting the transparent conductive layer 1b. It is characterized by being a layer composed of a material having the same.

<Nitrogen-containing layer 1a>
The nitrogen-containing layer 1a is a layer formed using a compound having a specific relationship with silver (Ag), which is a main material constituting the transparent conductive layer 1b, among compounds containing nitrogen atoms. . Here, the effective action energy ΔEef represented by the following formula (1) is defined as the energy that interacts between the compound and silver. And this effective action energy (DELTA) Eef comprises the nitrogen-containing layer 1a using the compound which has the specific relationship which satisfy | fills following formula (2).

  The number of nitrogen atoms in the compound that stably binds to silver [n] is selected from the nitrogen atoms contained in the compound as the specific nitrogen atom only from the nitrogen atoms that stably bind to silver Is the number counted. The nitrogen atoms to be selected are all nitrogen atoms contained in the compound, and are not limited to the nitrogen atoms constituting the heterocyclic ring. The selection of a specific nitrogen atom out of all the nitrogen atoms contained in such a compound is, for example, the bond distance [r (Ag · Ag · N)], or the angle between the nitrogen atom and silver, that is, the dihedral angle [D], relative to the ring containing the nitrogen atom in the compound, is performed as follows. The molecular orbital calculation is performed using, for example, Gaussian 03 (Gaussian, Inc., Wallingford, CT, 2003).

  First, when the bond distance [r (Ag · N)] is used as an index, considering the steric structure of each compound, the distance at which the nitrogen atom and silver are stably bonded in the compound is expressed as “stable bond distance”. ”Is set. Then, for each nitrogen atom contained in the compound, a bond distance [r (Ag · N)] is calculated using a molecular orbital calculation method. A nitrogen atom having a calculated bond distance [r (Ag · N)] close to the “stable bond distance” is selected as a specific nitrogen atom. Such selection of a nitrogen atom is applied to a compound containing many nitrogen atoms constituting a heterocyclic ring and a compound containing many nitrogen atoms not constituting a heterocyclic ring.

  When the dihedral angle [D] is used as an index, the dihedral angle [D] described above is calculated using a molecular orbital calculation method. And the nitrogen atom in which the calculated dihedral angle [D] makes a predetermined angle is selected as a specific nitrogen atom. Here, for example, a nitrogen atom having D <10 degrees is selected as a specific nitrogen atom. Such selection of a nitrogen atom using the dihedral angle [D] as an index is applied to a compound containing a large number of nitrogen atoms constituting a heterocyclic ring. In the selection of the nitrogen atom, the reason why the threshold value of the dihedral angle [D] is set to 10 degrees is as follows. That is, when the transparent conductive layer 1b is formed of a thin film having light transmittance adjacent to the nitrogen-containing layer 1a configured using a compound having a dihedral angle [D] of nitrogen atoms of 10 degrees or more, It was confirmed that the sheet resistance value cannot be measured in the transparent conductive layer 1b. From this, it is estimated that the nitrogen atom whose dihedral angle [D] is 10 degrees or more does not participate in the interaction with silver. For this reason, when the dihedral angle [D] is used as an index, only a nitrogen atom having a dihedral angle [D] of D <10 degrees is selected as a specific nitrogen atom.

  The interaction energy [ΔE] between silver (Ag) and nitrogen (N) in the compound can be calculated by a molecular orbital calculation method, and the mutual energy between nitrogen and silver selected as described above. The energy of action.

  Furthermore, the surface area [s] is calculated using Tencube / WM (manufactured by Tencube Co., Ltd.).

  The effective action energy ΔEef defined as described above is more preferably within a range satisfying the following formula (3).

  Moreover, as a compound containing the nitrogen atom which comprises the nitrogen containing layer 1a, the compound containing the heterocyclic ring which used the nitrogen atom (N) as the hetero atom, for example is used. Heterocycles having a nitrogen atom (N) as a hetero atom include aziridine, azirine, azetidine, azeto, azolidine, azole, azinane, pyridine, azepane, azepine, imidazole, pyrazole, oxazole, thiazole, imidazoline, pyrazine, pyridazine, pyrimidine Morpholine, thiazine, indole, isoindole, benzimidazole, purine, quinoline, isoquinoline, quinoxaline, cinnoline, pteridine, acridine, carbazole, benzo-C-cinnoline, porphyrin, chlorin, choline and the like. Among these, heterocyclic compounds containing one or two nitrogen atoms are exemplified.

  Moreover, as a compound which has a heterocyclic ring which used the nitrogen atom as the hetero atom, the compound preferably used is, for example, a compound represented by the following general formula (1) or a compound represented by the following general formula (2). Is done. In the present invention, the nitrogen-containing layer 1a provided adjacent to the transparent conductive layer 1b is selected from compounds represented by the above formula (1) or formula (2) among these general formulas (1) or (2). ) Is selected and used.

  In the formula of the general formula (1), Y5 represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof. E51 to E66 and E71 to E88 each represent -C (R3) = or -N =, and R3 represents a hydrogen atom or a substituent. However, at least one of E71 to E79 and at least one of E80 to E88 represents -N =. n3 and n4 represent an integer of 0 to 4, but n3 + n4 is an integer of 2 or more.

  In the general formula (1), examples of the arylene group represented by Y5 include o-phenylene group, p-phenylene group, naphthalenediyl group, anthracenediyl group, naphthacenediyl group, pyrenediyl group, naphthylnaphthalenediyl group, and biphenyldiyl. Groups (for example, [1,1′-biphenyl] -4,4′-diyl group, 3,3′-biphenyldiyl group, 3,6-biphenyldiyl group, etc.), terphenyldiyl group, quaterphenyldiyl group And kinkphenyldiyl group, sexiphenyldiyl group, septiphenyldiyl group, octiphenyldiyl group, nobiphenyldiyl group, deciphenyldiyl group and the like.

  In the general formula (1), examples of the heteroarylene group represented by Y5 include a carbazole ring, a carboline ring, a diazacarbazole ring (also referred to as a monoazacarboline ring, and one of the carbon atoms constituting the carboline ring is nitrogen. The ring structure is replaced by an atom), a triazole ring, a pyrrole ring, a pyridine ring, a pyrazine ring, a quinoxaline ring, a thiophene ring, an oxadiazole ring, a dibenzofuran ring, a dibenzothiophene ring, and an indole ring. And the like.

  As a preferred embodiment of the divalent linking group comprising an arylene group, a heteroarylene group or a combination thereof represented by Y5, among the heteroarylene groups, a condensed aromatic heterocycle formed by condensation of three or more rings. A group derived from a condensed aromatic heterocyclic ring formed by condensing three or more rings is preferably included, and a group derived from a dibenzofuran ring or a dibenzothiophene ring is preferable. Are preferred.

  In the general formula (1), examples of the substituent represented by R3 of —C (R3) ═ represented by E51 to E66 and E71 to E88 are alkyl groups (for example, methyl group, ethyl group, propyl group). Group, isopropyl group, tert-butyl group, 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 (aromatic carbocyclic group, aryl group, etc.), for example, phenyl group, p-chlorophenyl group Mesityl, tolyl, xylyl, naphthyl, anthryl, azulenyl, acenaphthenyl, fluore Group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group), 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, carbazolyl group, carbolinyl group, diazacarbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a phthalazinyl group, etc.) , Heterocyclic groups (for example, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy groups (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group) Group), cycloalkoxy (Eg, 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.), cycloalkylthio group (eg cyclopentylthio group, cyclohexylthio group etc.), arylthio group (eg phenylthio group, naphthylthio group etc.), alkoxycarbonyl group (eg methyloxycarbonyl group, ethyloxycarbonyl group) Butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), Rufamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthyl) Aminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (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) Butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonyl) Amino 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 Nyl group, 2-ethylhexylaminocarbonyl 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, ethylsulfonyl 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) Group, piperidyl group (also referred to as piperidinyl group), 2,2,6,6-tetramethylpiperidinyl group), halogen atom (for example, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group ( For example, fluorome Group, trifluoromethyl group, pentafluoroethyl 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.), phosphoric acid ester groups (eg, dihexyl phosphoryl group, etc.), phosphite ester groups (eg, diphenylphosphinyl group, etc.), phosphono groups, and the like.

  Some of these substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

  In general formula (1), it is preferable that 6 or more of E51 to E58 and 6 or more of E59 to E66 are each represented by -C (R3) =.

  In General formula (1), it is preferable that at least 1 of E75-E79 and at least 1 of E84-E88 represent -N =.

  Furthermore, in General formula (1), it is preferable that any one of E75-E79 and any one of E84-E88 represent -N =.

  Moreover, in General formula (1), it is mentioned as a preferable aspect that E71-E74 and E80-E83 are each represented by -C (R3) =.

  Furthermore, in the compound represented by the general formula (1), it is preferable that E53 is represented by -C (R3) = and R3 represents a linking site, and E61 is also represented by -C (R3) =. And R3 preferably represents a linking site.

  Further, E75 and E84 are preferably represented by -N =, and E71 to E74 and E80 to E83 are each preferably represented by -C (R3) =.

Moreover, the compound represented by following General formula (2) is used as another example of the compound which comprises the nitrogen containing layer 1a.

  In the general formula (2), at least one of T11 and T12 is a nitrogen atom, at least one of T21 to T25 is a nitrogen atom, and at least one of T31 to T35 is Nitrogen atom.

  In the general formula (2), R represents a substituent. As an example of a substituent, the substituent illustrated as R3 of General formula (1) is applied similarly.

  When the nitrogen-containing layer 1a as described above is formed on a substrate, the film forming method includes a method using a wet process such as a coating method, an inkjet method, a coating method, a dip method, or a vapor deposition method. (Resistance heating, EB method, etc.), a method using a dry process such as a sputtering method, a CVD method, or the like. Of these, the vapor deposition method is preferably applied.

[Specific examples of compounds]
Although the specific example (1-118) of the compound which comprises the nitrogen containing layer 1a below is shown, it is not limited to these. In addition, the compound which is not contained in the said General formula (1) and General formula (2) here is illustrated here. Further, in the present invention, the nitrogen-containing layer 1a provided adjacent to the transparent conductive layer 1b is composed of a compound applicable to the above formula (1) or formula (2) among the compounds (1 to 118) exemplified below. Select and use.

[Examples of compound synthesis]
Specific examples of the synthesis of compound 5 are shown below as typical synthesis examples of the compound, but are not limited thereto.

Step 1: (Synthesis of Intermediate 1)
Under a nitrogen atmosphere, 2,8-dibromodibenzofuran (1.0 mol), carbazole (2.0 mol), copper powder (3.0 mol), potassium carbonate (1.5 mol), DMAc (dimethylacetamide) 300 ml Mixed in and stirred at 130 ° C. for 24 hours. The reaction solution thus obtained was cooled to room temperature, 1 L of toluene was added, washed with distilled water three times, the solvent was distilled off from the washed product under a reduced pressure atmosphere, and the residue was subjected to silica gel flash chromatography (n-heptane: Purification was performed using toluene = 4: 1 to 3: 1), and Intermediate 1 was obtained with a yield of 85%.

Step 2: (Synthesis of Intermediate 2)
Intermediate 1 (0.5 mol) was dissolved in 100 ml of DMF (dimethylformamide) at room temperature under air, NBS (N-bromosuccinimide) (2.0 mol) was added, and the mixture was stirred overnight at room temperature. The resulting precipitate was filtered and washed with methanol, yielding intermediate 2 in 92% yield.

Step 3: (Synthesis of Compound 5)
Under a nitrogen atmosphere, intermediate 2 (0.25 mol), 2-phenylpyridine (1.0 mol), ruthenium complex [(η ₆ -C ₆ H ₆ ) RuCl ₂ ] ₂ (0.05 mol), triphenyl Phosphine (0.2 mol) and potassium carbonate (12 mol) were mixed in 3 L of NMP (N-methyl-2-pyrrolidone) and stirred at 140 ° C. overnight.

After cooling the reaction solution to room temperature, 5 L of dichloromethane was added, and the reaction solution was filtered. Next, the solvent was distilled off from the filtrate under reduced pressure (800 Pa, 80 ° C.), and the residue was purified by silica gel flash chromatography (CH ₂ Cl ₂ : Et ₃ N = 20: 1 to 10: 1).

  After distilling off the solvent from the purified product under reduced pressure, the residue was dissolved again in dichloromethane and washed three times with water. The material obtained by washing was dried over anhydrous magnesium sulfate, and the solvent was distilled off from the dried material in a reduced-pressure atmosphere to obtain Compound 5 in a yield of 68%.

<Transparent conductive layer 1b>
The transparent conductive layer 1b is a layer formed using silver or an alloy containing silver as a main component, and is a layer formed adjacent to the nitrogen-containing layer 1a.

  In the case where the transparent conductive layer 1b is made of silver (Ag), Ag is contained at 98 atms% or more. Moreover, when the transparent conductive layer 1b is comprised with the alloy which has silver (Ag) as a main component, it shall contain 50 atms% or more of silver (Ag). Metals used in combination with silver (Ag) are aluminum (Al), indium (In), tin (Sn), copper (Cu), palladium (Pd), gold (Au), platinum (Pt), magnesium (Mg) ) Etc.

  The transparent conductive layer 1b as described above may have a structure in which silver or an alloy layer mainly composed of silver is divided into a plurality of layers as necessary.

  Furthermore, the transparent conductive layer 1b preferably has a thickness in the range of 4 to 12 nm. The film thickness of 12 nm or less is preferable because the absorption component or reflection component of the layer can be kept low and the light transmittance of the transparent conductive layer can be maintained. Moreover, the electroconductivity of a layer is also ensured because a film thickness is 4 nm or more.

  As a method for forming such a transparent 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, or a CVD method is used. And a method using a dry process such as Of these, the vapor deposition method is preferably applied. In addition, the transparent conductive layer 1b is formed on the nitrogen-containing layer 1a so that it has sufficient conductivity even without high-temperature annealing after the film formation, etc. It may be one that has been subjected to high-temperature annealing after film formation.

<Effect of transparent conductive layer>
The transparent conductive layer 1b configured as described above is provided using silver or an alloy containing silver as a main component adjacent to the nitrogen-containing layer 1a configured using a compound containing nitrogen atoms. It is. Thus, when forming the transparent conductive layer 1b adjacent to the nitrogen-containing layer 1a, the silver atoms constituting the transparent conductive layer 1b interact with the compound containing nitrogen atoms constituting the nitrogen-containing layer 1a. The diffusion distance of silver atoms on the surface of the nitrogen-containing layer 1a is reduced, and aggregation of silver is suppressed. Therefore, in general, a silver thin film that is easily isolated in an island shape by film growth of a nuclear growth type (Volume-Weber: VW type) is a single-layer growth type (Frank-van der Merwe: FW type) film growth. As a result, a film is formed. Therefore, the transparent conductive layer 1b having a uniform film thickness can be obtained even though the film thickness is small.

  In particular, the effective action energy ΔEef shown in the above formula (1) is defined as the energy that interacts between the compound that forms the nitrogen-containing layer 1a and the silver that forms the transparent conductive layer 1b. The nitrogen-containing layer 1a is configured using a compound satisfying −0.5 ≦ ΔEef ≦ −0.10. This makes it possible to form the nitrogen-containing layer 1a using a compound that can reliably obtain the effect of “suppressing the aggregation of silver” as described above. This is because, as will be described in detail in a later embodiment, on such a nitrogen-containing layer 1a, there is a transparent conductive layer 1b that can measure sheet resistance by the four-probe method while being an extremely thin film. It was also confirmed from the formation.

  As a result, the transparent conductive layer 1b which is adjacent to such a nitrogen-containing layer 1a and has a uniform film thickness while ensuring light transmission while having a thin film thickness is ensured. Therefore, it is possible to achieve both improvement in conductivity and improvement in light transmission in the transparent conductive layer 1b using silver.

  Further, such a transparent conductive layer 1b is low-cost because it does not use indium (In), which is a rare metal, as a main component, and long-term reliability because it does not use a chemically unstable material such as ZnO. Also excellent.

≪2. Configuration of organic electroluminescent element used in display device >>
FIG. 2 is a schematic cross-sectional view of a main part for explaining the configuration of an organic electroluminescent element EL having a tandem structure using the above-described transparent conductive layer 1b. Hereinafter, the configuration of the organic electroluminescent element EL will be described with reference to this figure.

<Configuration of organic electroluminescence element EL>
The organic electroluminescent element EL shown in FIG. 2 is provided on the substrate 11, and in order from the substrate 11 side, the first electrode 5, the first light emitting unit 3-1, the nitrogen-containing layer 1a-1, the transparent conductive material. The layer 1b-1, the second light emitting unit 3-2, the nitrogen-containing layer 1a-2, the transparent conductive layer 1b-2, the third light emitting unit 3-3, and the second electrode 7 are laminated in this order. It is configured. In this organic electroluminescent element EL, a laminated body of a nitrogen-containing layer 1a-1 and a transparent conductive layer 1b-1 is sandwiched between the light emitting units 3-1, 3-2, and the light emitting units 3-2, 3- 3 is characterized in that a laminate of a nitrogen-containing layer 1a-2 and a transparent conductive layer 1b-2 is sandwiched.

  Hereinafter, details of the main layers constituting the organic electroluminescent element EL will be described in detail with respect to the substrate 11, the first electrode 5 and the second electrode 7, the nitrogen-containing layers 1a-1, 1a-2, and the transparent conductive layers 1b-1, 1b-2. The light emitting units 3-1, 3-2, 3-3, other components, and the method for manufacturing the organic electroluminescent element will be described in this order.

<Substrate 11>
Examples of the substrate 11 on which the organic electroluminescent element EL is provided include glass and plastic, but are not limited thereto. The substrate 11 may be transparent or opaque. In the case where the organic electroluminescent element EL is a bottom emission type in which light is extracted from the substrate 11 side, the substrate 11 is preferably transparent. Examples of the transparent substrate 11 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. As will be described later, when the first electrode 5 also has a laminated structure of a nitrogen-containing layer and a transparent conductive layer, the surface of these glass materials has adhesion, durability, and smoothness to the nitrogen-containing layer. From this point of view, if necessary, physical treatment such as polishing is performed, a film made of an inorganic material or an organic material, or a hybrid film combining these films is formed.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate propionate (CAP), Cellulose esters such as cellulose acetate phthalate (TAC) and 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) of 0.01 g / (measured by a method according to JIS-K-7129-1992. 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 10 ⁻³ ml / (m ² · 24 hours · atm) or less, and the water vapor permeability is 10 ⁻⁵ g / (m ² · 24 hours) or less high barrier film is preferable.

  The material for forming the barrier film as described above may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like is used. be able to. 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. A combination method, a plasma CVD method, 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 is particularly preferable.

  On the other hand, when the substrate 11 is opaque, for example, a metal substrate such as aluminum or stainless steel, an opaque resin substrate, a ceramic substrate, or the like can be used. These substrates may be in the form of a film that bends flexibly.

<First electrode 5 and second electrode 7>
One of the first electrode 5 and the second electrode 7 functions as an anode for supplying holes to the light emitting units 3-1, 3-2, and 3-3, and either one of them is the light emitting unit 3-1. , 3-2 and 3-3 function as a cathode for supplying electrons. Here, as an example, the first electrode 5 on the substrate 11 side is an anode, the opposite second electrode 7 is a cathode, and a driving voltage is applied to each.

  The first electrode 5 and the second electrode 7 are electrode layers in which at least one or both functions as a transparent electrode. For example, when the first electrode 5 on the substrate 11 side is configured as a transparent electrode, the emitted light h generated in the light emitting units 3-1, 3-2 and 3-3 is extracted from the substrate 11 side, and this organic electric field The light emitting element EL is a bottom emission type. On the other hand, when the second electrode 7 is configured as a transparent electrode, the emitted light h generated by the light emitting units 3-1, 3-2, 3-3 is extracted from the side opposite to the substrate 11, and this organic electroluminescent element is obtained. EL is a top emission type. In the above case, the other electrode may be an electrode film that functions as a reflective electrode. On the other hand, when both the 1st electrode 5 and the 2nd electrode 7 are comprised as a transparent electrode, this organic electroluminescent element EL becomes a double-sided light emission type | mold. Here, for example, it is assumed that the first electrode 5 is configured as a transparent electrode.

For the first electrode 5 and the second electrode 7 as described above, for example, a metal, an alloy, an organic or inorganic conductive compound, and a mixture thereof are used. Specifically, gold, 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 and oxide semiconductors such as SnO ₂ . The first electrode 5 and the second electrode 7 are configured by selecting a material suitable as a cathode material or an anode material from these materials.

Of the first electrode 5 and the second electrode 7, the electrode on the light extraction side (here, the first electrode) is composed of a material having good light transmittance among these materials. To do. Examples of such a material include oxide semiconductors such as ITO, ZnO, TiO ₂ , and SnO ₂ .

  The first electrode 5 and the second electrode 7 may have a laminated structure as necessary. In such a configuration, only a portion where the light emitting units 3-1, 3-2, and 3-3 are sandwiched between the first electrode 5 and the second electrode 7 is a light emitting region in the organic electroluminescent element EL.

  The first electrode 5 and the second electrode 7 as described above can be produced by forming a thin film from these conductive materials by a method such as vapor deposition or sputtering. At this time, the sheet resistance as the first electrode 5 and the second electrode 7 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 nm to 200 nm. Further, the vapor deposition method is applied to the second electrode 7 on the upper part of the light emitting unit 3-3.

<Nitrogen-containing layers 1a-1, 1a-2 and transparent conductive layers 1b-1, 1b-2>
The nitrogen-containing layers 1a-1 and 1a-2 and the transparent conductive layers 1b-1 and 1b-2 have the structures described above. Here, for example, the nitrogen-containing layer 1a-1 and the transparent layer are sequentially formed from the substrate 11 side. A conductive layer 1b-1 is disposed, and similarly, a nitrogen-containing layer 1a-2 and a transparent conductive layer 1b-2 are disposed. When the first electrode 5 is an anode and the second electrode 7 is a cathode, the transparent conductive layer 1b-1 functions as a cathode for the light emitting unit 3-1 on the first electrode (anode) 5 side. Further, it functions as an anode for the light emitting unit 3-2 on the second electrode (cathode) 7 side. The same applies to the transparent conductive layer 1b-2.

  The nitrogen-containing layer 1a-1 sandwiched between the light emitting unit 3-1 and the transparent conductive layer 1b-1 is also regarded as a layer constituting a part of the light emitting unit 3-1. Similarly, the nitrogen-containing layer 1a-2 sandwiched between the light emitting unit 3-2 and the transparent conductive layer 1b-2 is regarded as a layer constituting a part of the light emitting unit 3-2.

  In this case, the transparent conductive layer 1b-1 functions as a cathode for the light emitting unit 3-1, and the transparent conductive layer 1b-2 functions as a cathode for the light emitting unit 3-2. Therefore, the nitrogen-containing layers 1a-1 and 1a-2 are configured by using a material having an electron transporting property or an electron injecting property from materials satisfying the above-described formula (1) or (2). Is preferred. Further, such nitrogen-containing layers 1a-1 and 1a-2 may be configured using a material satisfying the formula (1) or the formula (2) among the materials exemplified as the electron transport material hereinafter. .

  As described above, when the nitrogen-containing layers 1a-1 and 1a-2 are used as layers having an electron transport property or an electron injection property, these nitrogen-containing layers 1a-1 and 1a-2 include alkali metals and alkali metals. A salt, or an alkaline earth metal or alkaline earth metal salt may be mixed and contained. Specific examples include metals such as lithium, potassium, sodium, cesium, magnesium, calcium, and strontium, and salts thereof. As a method of mixing and adding, preferred is co-evaporation with a nitrogen-containing compound. Thereby, the moving speed to the light emitting layer of the electron inject | poured from the cathode can be improved, and luminous efficiency can be improved.

  If the first electrode 5 is a cathode and the second electrode 7 is an anode, the transparent conductive layer 1b-1 functions as an anode for the light emitting unit 3-1 on the first electrode (cathode) 5 side. Therefore, the nitrogen-containing layer 1a-1 between the transparent conductive layer 1b-1 and the light emitting unit 3-1 is preferably configured using a material having a hole transporting property or a hole injecting property. The same applies to the transparent conductive layer 1b-2 and the nitrogen-containing layer 1a-2.

  A driving voltage is applied to the transparent conductive layers 1 b-1 and 1 b-2 together with the first electrode 5 and the second electrode 7.

<Light-emitting units 3-1, 3-2, 3-3>
The light emitting units 3-1, 3-2, and 3-3 are not limited in the overall layer structure, and each may have a general layer structure. As an example, a configuration in which [hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer] is stacked in order from the anode side is exemplified, and among these, at least an organic material is used. It is essential to have a light emitting layer. The hole injection layer and the hole transport layer may be provided as a hole transport / injection layer. The electron transport layer and the electron injection layer may be provided as an electron transport / injection layer. Of the layers constituting each light emitting unit 3-1, 3-2, 3-3, for example, the electron injection layer may be composed of an inorganic material.

  In addition to these layers, the light emitting units 3-1, 3-2, and 3-3 may have a hole blocking layer, an electron blocking layer, and the like stacked as necessary. Furthermore, the light emitting layer may be formed as a light emitting layer unit by laminating a plurality of light emitting layers via a non-light emitting intermediate layer. The intermediate layer may function as a hole blocking layer and an electron blocking layer.

  In particular, each of the light emitting units 3-1, 3-2, and 3-3 is configured to obtain emitted light h of a different color. For example, the light emitting unit 3-1 that obtains blue (B) emitted light hb, green A light emitting unit 3-2 from which (G) emitted light hg is obtained and a light emitting unit 3-3 from which red (R) emitted light hr is obtained. These light emitting units 3-1, 3-2, and 3-3 are assumed to have a shorter emission wavelength of the emitted light h as they are arranged closer to the light extraction side. Therefore, here, in order from the substrate 11 side, the light emitting unit 3-1 that can obtain the blue (B) emitted light hb, the light emitting unit 3-2 that can obtain the green (G) emitted light hg, and the red (R) A light emitting unit 3-3 from which the emitted light hr can be obtained is stacked.

  Thereby, the configuration of the light emitting layer in the green (G) light emitting unit 3-2 and the red (R) light emitting unit 3-3 arranged on the emission side by the blue (B) light emitting light hb having high energy. It is possible to prevent the substance from being excited, and light emission of a light emission color with good controllability is extracted from the substrate 11 side.

  Hereinafter, each layer constituting the light emitting units 3-1, 3-2, and 3-3 will be described in the order of the light emitting layer, the injection layer, the hole transport layer, the electron transport layer, and the blocking layer.

[Light emitting layer]
The light emitting layer used in the present invention contains, for example, a phosphorescent light emitting compound as a light emitting material.

  This light emitting layer is a layer that emits light by recombination of electrons injected from the electrode or the electron transport layer and holes injected from the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. Alternatively, it may be the interface between the light emitting layer and the adjacent layer.

  As such a light emitting layer, there is no restriction | limiting in particular in the structure, if the light emitting material contained satisfy | fills 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 intermediate layer (not shown) between the light emitting layers.

  The total thickness of the light emitting layers is preferably in the range of 1 to 100 nm, and more preferably 1 to 30 nm because a lower driving voltage can be obtained. Note that the total film thickness of the light emitting layer is a film thickness including the intermediate layer when a non-light emitting intermediate layer exists between the light emitting layers.

  In the case of a light emitting layer having a configuration in which a plurality of layers are laminated, the thickness of each light emitting layer is preferably adjusted to a range of 1 to 50 nm, more preferably adjusted to a range of 1 to 20 nm.

  The light emitting layer as described above is formed by forming a light emitting material or a host compound 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 do.

  In the light emitting layer, a plurality of light emitting materials may be mixed, and a phosphorescent light emitting material and a fluorescent light emitting material (also referred to as a fluorescent dopant or a fluorescent compound) may be mixed and used in the same light emitting layer.

  As a structure of the light emitting layer, it is preferable that a light emitting material contains 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) and emits light.

(Host compound)
As the host compound contained in the light emitting layer, 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 a light emitting layer.

  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 efficiency of the organic electroluminescent element EL can be improved. 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, preventing an increase in emission wavelength, and having a high Tg (glass transition temperature) compound is preferable. The glass transition point (Tg) here is a value obtained by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).

  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 compounds H68 to H79, x and y represent the ratio of the random copolymer. The ratio can be, for example, x: y = 1: 10.

  As specific examples of known host compounds, compounds described in the following documents may be used. 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.

(Luminescent material)
As a light-emitting material that can be used in the present invention, a phosphorescent compound (also referred to as a phosphorescent compound or a phosphorescent material) can be given.

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

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of the Fourth Edition Experimental Chemistry Course 7. Although the phosphorescence quantum yield in a solution can be measured using various solvents, when using a phosphorescent compound in the present invention, the above phosphorescence quantum yield (0.01 or more) is achieved in any solvent. It only has to be done.

  There are two types of light emission principles of the phosphorescent compound. One is that recombination of carriers occurs on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent compound to obtain light emission from the phosphorescent compound. The other is a carrier trap type in which the phosphorescent compound becomes a carrier trap, and carriers are recombined on the phosphorescent compound to emit light from the phosphorescent compound. In either case, it is a condition 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 electroluminescence device, but preferably contains a metal of group 8 to 10 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 may contain two or more phosphorescent compounds, and the concentration ratio of the phosphorescent compounds in the light emitting layer may vary in the thickness direction of the light emitting layer. Good.

  The phosphorescent compound is preferably 0.1% by volume or more and less than 30% by volume based on the total amount of the light emitting layer.

(Compound represented by the general formula (3))
The compound (phosphorescent compound) contained in the light emitting layer is preferably a compound represented by the following general formula (3).

  Note that the phosphorescent compound represented by the general formula (3) (also referred to as a phosphorescent metal complex) is preferably contained as a light emitting dopant in the light emitting layer of the organic electroluminescent element EL. It may be contained in a light emitting functional layer other than the light emitting layer.

  In the general formula (3), P and Q each represent a carbon atom or a nitrogen atom, and A1 represents an atomic group that forms an aromatic hydrocarbon ring or an aromatic heterocyclic ring together with P—C. A2 represents an atomic group which forms an aromatic heterocycle with QN. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element in the periodic table.

  In general formula (3), P and Q each represent a carbon atom or a nitrogen atom.

  In the general formula (3), the aromatic hydrocarbon ring that A1 forms with P—C includes a 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, Examples include a picene ring, a pyrene ring, a pyranthrene ring, and an anthraanthrene ring.

  These rings may further have a substituent represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1).

  In the general formula (3), the aromatic heterocycle formed by A1 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, 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, azacarbazole A ring etc. are mentioned.

  Here, the azacarbazole ring refers to one in which one or more carbon atoms of the benzene ring constituting the carbazole ring are replaced with a nitrogen atom.

  These rings may further have a substituent represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1).

  In the general formula (3), examples of the aromatic heterocycle formed by A2 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 a thiazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, a pyrazole ring, and a triazole ring.

  These rings may further have a substituent represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1).

  In the general formula (3), P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2.

  Examples of the bidentate ligand represented by P1-L1-P2 include phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabol, acetylacetone, and picolinic acid.

  In general formula (3), 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 the general formula (3), M1 is a transition metal element of Group 8 to Group 10 (also simply referred to as a transition metal) in the periodic table, and is preferably iridium.

(Compound represented by the general formula (4))
Among the compounds represented by the general formula (3), a compound represented by the following general formula (4) is more preferable.

  In the general formula (4), Z represents a hydrocarbon ring group or a heterocyclic group. P and Q each represent a carbon atom or a nitrogen atom, and A1 represents an atomic group that forms an aromatic hydrocarbon ring or an aromatic heterocyclic ring together with PC. A3 represents -C (R01) = C (R02)-, -N = C (R02)-, -C (R01) = N- or -N = N-, and each of R01 and R02 represents a hydrogen atom or a substituent. Represents a group. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element in the periodic table.

  In the general formula (4), 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 may have a substituent exemplified as R3 in the general formula (1).

  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 represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1).

  In the general formula (4), examples of the heterocyclic group represented by Z include a non-aromatic heterocyclic group and an aromatic heterocyclic group. Examples of the non-aromatic heterocyclic group include an epoxy ring and an aziridine group. 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, 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine Ring, thiomorpholine-1,1-dioxide And groups derived from a ring, a pyranose ring, a diazabicyclo [2,2,2] -octane ring, and the like.

  These groups may be unsubstituted or may have a substituent represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1).

  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 (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is 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 represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1).

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

  In the general formula (4), the aromatic hydrocarbon ring that A1 forms with P—C includes a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a chrysene ring, and a 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 represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1).

  In the general formula (4), the aromatic heterocycle formed by A1 together with PC includes furan ring, thiophene ring, oxazole ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzo Imidazole 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, And azacarbazole ring.

  Here, the azacarbazole ring refers to one in which one or more carbon atoms of the benzene ring constituting the carbazole ring are replaced with a nitrogen atom.

  These rings may further have a substituent represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1).

  In -C (R01) = C (R02)-, -N = C (R02)-, and -C (R01) = N- represented by A3 in the general formula (4), each represented by R01 and R02 In general formula (1), the substituent is synonymous with the substituent represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88.

  In the general formula (4), examples of the bidentate ligand represented by P1-L1-P2 include phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabole, acetylacetone, and picolinic acid. .

  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 General Formula (4), Group 8 to Group 10 transition metal elements in the periodic table of elements represented by M1 (also simply referred to as transition metals) in General Formula (3) are represented in the periodic table of elements represented by M1. It is synonymous with the transition metal element of Group 8-10.

(Compound represented by the general formula (5))
One preferred embodiment of the compound represented by the general formula (4) is a compound represented by the following general formula (5).

In the general formula (5), 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. Z1 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. Z2 represents an atomic group necessary for forming a hydrocarbon ring group or a heterocyclic group. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element 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 (5), each of the substituents represented by R ₀₃ , R ₀₄ , R ₀₅ , and R ₀₆ is represented by —C (R 3) represented by E51 to E66 and E71 to E88, respectively, in the general formula (1). ) = Synonymous with the substituent represented by R3.

  In the general formula (5), examples of the 6-membered aromatic hydrocarbon ring formed by Z1 together with C—C include a benzene ring.

  These rings may further have a substituent represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1).

  In the general formula (5), examples of the 5- or 6-membered aromatic heterocycle formed by Z1 together with C—C include an oxazole ring, an oxadiazole ring, an oxatriazole ring, an isoxazole ring, a tetrazole ring, and a thiadiazole. And a ring, a thiatriazole ring, an isothiazole ring, a thiophene ring, a furan ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, a pyrazole ring, and a triazole ring.

  These rings may further have a substituent represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1).

  In the general formula (5), examples of the hydrocarbon ring group represented by Z2 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 may have a substituent exemplified as R3 in the general formula (1).

  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 represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88, respectively, in the general formula (1).

  In the general formula (5), examples of the heterocyclic group represented by Z2 include a non-aromatic heterocyclic group and an aromatic heterocyclic group. Examples of the non-aromatic heterocyclic group include an epoxy ring and an aziridine group. 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, 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine Ring, thiomorpholine-1,1-dioxy And groups derived from a dodo ring, a pyranose ring, a diazabicyclo [2,2,2] -octane ring, and the like. These groups may be unsubstituted or may have a substituent represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1). .

  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 (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), quinoxalinyl Group, pyridazinyl group, triazinyl group, key Zoriniru group, phthalazinyl group, and the like.

  These rings may be unsubstituted, and may further have a substituent represented by R3 of -C (R3) = represented by E51 to E66 and E71 to E88 in the general formula (1). .

  In the general formula (5), the group formed by Z1 and Z2 is preferably a benzene ring.

  In the general formula (5), the bidentate ligand represented by P1-L1-P2 has the same meaning as the bidentate ligand represented by P1-L1-P2 in the general formula (3). .

  In general formula (5), the transition metal element of group 8 to group 10 in the periodic table of elements represented by M1 is the transition of group 8 to group 10 in the periodic table of elements represented by M1 in general formula (3). Synonymous with metal element.

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

  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 compound). Rare earth complexes, most preferably iridium compounds.

  Specific examples (Pt-1 to Pt-3, A-1, Ir-1 to Ir-50) 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 above phosphorescent compounds (also referred to as phosphorescent metal complexes and the like) are 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: hole injection layer, electron injection layer]
An injection layer is a layer provided between an electrode and a light-emitting layer in order to lower drive voltage or improve light emission luminance. “An organic EL element and its forefront of industrialization (November 30, 1998, NTS) (Published by the company) "Chapter 2 Chapter 2" Electrode Material "(pages 123-166) in detail, there are a hole injection layer and an electron injection layer.

  The injection layer can be provided as necessary. If it is a hole injection layer, it may be present between the anode and the light emitting layer or the hole transport layer, and if it is an electron injection layer, it may be present between the cathode and the light emitting layer or the electron transport layer.

  The details of the hole injection layer are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069, and the like. As a specific example, a phthalocyanine layer represented by copper phthalocyanine And 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 are also described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like, and specifically, metals represented by strontium, aluminum and the like. Examples thereof include 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. The electron injection layer of the present invention is desirably a very thin film, and although it depends on the material, the film thickness is preferably in the range of 1 nm to 10 μm.

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

  The hole transport material has any one 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 (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; 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, as well as two of those described in US Pat. No. 5,061,569 Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the like.

  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 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. Can do. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. This hole transport layer may have a single layer structure composed of one or more of the above materials.

  In addition, the hole transport layer material can be doped with impurities to increase the p property. 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 because an element with lower power consumption can be manufactured.

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

  As an electron transport material (also serving as a hole blocking material) constituting a layer portion adjacent to the light emitting layer in the electron transport layer having a single layer structure and the electron transport layer having a multilayer structure, electrons injected from the cathode are used as the light emitting layer. What is necessary is just to have the function to transmit. 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. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the 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 can also be used as a material for the electron transport layer. it can. 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.

  Also, metal complexes of 8-quinolinol derivatives, such as tris (8-quinolinol) aluminum (Alq3), 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 (Znq), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga, or Pb can also be used as the material for the electron transport layer.

  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. Further, distyrylpyrazine derivatives exemplified as the material of the light emitting layer can also be used as the material of the electron transport layer, and n-type-Si, n-type-SiC, etc. as well as the hole injection layer and the hole transport layer. These inorganic semiconductors can also be used as a material for the electron transport layer.

  The electron transport layer 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 inkjet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  In addition, the electron transport layer 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 potassium, a potassium compound, etc. are contained in an electron carrying layer. As the potassium compound, for example, potassium fluoride can be used. Thus, when the n property of the electron transport layer is increased, an element with lower power consumption can be manufactured.

  Moreover, as a material (electron transport compound) of an electron carrying layer, Preferably, the compound represented by following General formula (6) can be used.

(Ar1) n1-Y1 General formula (6)

  In the formula (6), n1 represents an integer of 1 or more, Y1 represents a substituent when n1 is 1, and represents a single bond or an n1-valent linking group when n1 is 2 or more. Ar1 represents a group represented by the general formula (A) described later. When n1 is 2 or more, a plurality of Ar1s may be the same or different. However, the compound represented by the general formula (6) has at least two condensed aromatic heterocycles in which three or more rings are condensed in the molecule.

  In the general formula (6), examples of the substituent represented by Y1 are represented by E51 to E66 and E71 to E88 in the general formula (1) shown as the compounds constituting the nitrogen-containing layer 1a described above. It is synonymous with the substituent represented by R3 of -C (R3) =.

  Specific examples of the n1-valent linking group represented by Y1 in the general formula (6) include a divalent linking group, a trivalent linking group, and a tetravalent linking group.

In the general formula (6), as the divalent linking group represented by Y1, an alkylene group (for example, ethylene group, trimethylene group, tetramethylene group, propylene group, ethylethylene group, pentamethylene group, hexamethylene group, 2,2,4-trimethylhexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, cyclohexylene group (for example, 1,6-cyclohexanediyl group, etc.), Cyclopentylene group (for example, 1,5-cyclopentanediyl group and the like), alkenylene group (for example, vinylene group, propenylene group, butenylene group, pentenylene group, 1-methylvinylene group, 1-methylpropenylene group, 2-methylpropenylene group, 1-methylpentenylene group, 3-methyl Ntenylene group, 1-ethylvinylene group, 1-ethylpropenylene group, 1-ethylbutenylene group, 3-ethylbutenylene group, etc.), alkynylene group (for example, ethynylene group, 1-propynylene group, 1-butynylene group, 1-pentynylene group) 1-hexynylene group, 2-butynylene group, 2-pentynylene group, 1-methylethynylene group, 3-methyl-1-propynylene group, 3-methyl-1-butynylene group, etc.), arylene group (for example, o-phenylene group) , P-phenylene group, naphthalenediyl group, anthracenediyl group, naphthacenediyl group, pyrenediyl group, naphthylnaphthalenediyl group, biphenyldiyl group (for example, [1,1′-biphenyl] -4,4′-diyl group, 3, 3′-biphenyldiyl group, 3,6-biphenyldiyl group, etc.), terfeni Diyl group, quaterphenyldiyl group, kinkphenyldiyl group, sexiphenyldiyl group, septiphenyldiyl group, octiphenyldiyl group, nobiphenyldiyl group, deciphenyldiyl group, etc.), heteroarylene group (for example, carbazole) Ring, carboline ring, diazacarbazole ring (also called monoazacarboline ring, which shows a ring structure in which one of carbon atoms constituting carboline ring is replaced by nitrogen atom), triazole ring, pyrrole ring, pyridine ring, pyrazine Ring, quinoxaline ring, thiophene ring, oxadiazole ring, dibenzofuran ring, dibenzothiophene ring, divalent group derived from the group consisting of indole ring, etc.), chalcogen atom such as oxygen and sulfur, 3 or more rings A group derived from a condensed aromatic heterocycle formed by condensation (here, The condensed aromatic heterocyclic ring formed by condensing three or more rings is preferably an aromatic heterocyclic condensed ring containing a hetero atom selected from N, O and S as an element constituting the condensed ring. Specifically, acridine ring, benzoquinoline ring, carbazole ring, phenazine ring, phenanthridine ring, phenanthroline ring, carboline ring, cyclazine ring, quindrine ring, tepenidine ring, quinindrine ring, triphenodithiazine ring , Triphenodioxazine ring, phenanthrazine ring, anthrazine ring, perimidine ring, diazacarbazole ring (representing any one of carbon atoms constituting a carboline ring replaced by a nitrogen atom), phenanthroline ring, dibenzofuran ring, Dibenzothiophene ring, naphthofuran ring, naphthothiophene ring, ben Difuran ring, benzodithiophene ring, naphthodifuran ring, naphthodithiophene ring, anthrafuran ring, anthradifuran ring, anthrathiophene ring, anthradithiophene ring, thianthrene ring, phenoxathiin ring, thiophanthrene ring (naphthothiophene ring) ) Etc.).

  In the general formula (6), examples of the trivalent linking group represented by Y1 include ethanetriyl group, propanetriyl group, butanetriyl group, pentanetriyl group, hexanetriyl group, heptanetriyl group, and octanetriyl. Group, nonanetriyl group, decanetriyl group, undecanetriyl group, dodecanetriyl group, cyclohexanetriyl group, cyclopentanetriyl group, benzenetriyl group, naphthalenetriyl group, pyridinetriyl group, carbazoletriyl group, etc. Can be mentioned.

  In the general formula (6), the tetravalent linking group represented by Y1 is a group in which one trivalent group is further added to the above trivalent group, and examples thereof include a propanediylidene group and 1,3-propane. Diyl-2-ylidene group, butanediylidene group, pentanediylidene group, hexanediylidene group, heptanediylidene group, octanediylidene group, nonanediylidene group, decandiylidene group, undecandiylidene group, dodecandiylidene group, cyclohexanediylidene group , Cyclopentanediylidene group, benzenetetrayl group, naphthalenetetrayl group, pyridinetetrayl group, carbazoletetrayl group and the like.

  The divalent linking group, the trivalent linking group, and the tetravalent linking group are each further represented by -51 (E3) to E66 and E71 to E88 in the general formula (1). May have a substituent represented by R3.

  As a preferred embodiment of the compound represented by the general formula (6), Y1 preferably represents a group derived from a condensed aromatic heterocycle formed by condensation of three or more rings, and the three or more rings. As the condensed aromatic heterocyclic ring formed by condensing, a dibenzofuran ring or a dibenzothiophene ring is preferable. Further, n1 is preferably 2 or more.

  Furthermore, the compound represented by the general formula (6) has at least two condensed aromatic heterocycles obtained by condensing the above three or more rings in the molecule.

  When Y1 represents an n1-valent linking group, Y1 is preferably non-conjugated in order to keep the triplet excitation energy of the compound represented by the general formula (6) high, and further, Tg (glass transition In view of improving the point, also referred to as glass transition temperature, it is preferably composed of an aromatic ring (aromatic hydrocarbon ring + aromatic heterocycle).

  Here, the term “non-conjugated” means that the linking group cannot be expressed by repeating a single bond (also referred to as a single bond) and a double bond, or the conjugation between aromatic rings constituting the linking group is sterically cleaved. Means.

(Group represented by general formula (A))
Ar1 in the general formula (6) represents a group represented by the following general formula (A).

  In the formula, X represents —N (R) —, —O—, —S— or —Si (R) (R ′) —, and E1 to E8 represent —C (R1) ═ or —N═. R, R ′ and R1 each represent a hydrogen atom, a substituent or a linking site with Y1. * Represents a linking site with Y1. Y2 represents a simple bond or a divalent linking group. Y3 and Y4 each represent a group derived from a 5-membered or 6-membered aromatic ring, and at least one represents a group derived from an aromatic heterocycle containing a nitrogen atom as a ring constituent atom. n2 represents an integer of 1 to 4.

  Here, in —N (R) — or —Si (R) (R ′) — represented by X in the general formula (A), and —C (R1) = represented by E1 to E8, The substituents represented by R, R ′ and R1 have the same meaning as the substituents represented by R3 of —C (R3) ═ represented by E51 to E66 and E71 to E88 in the general formula (1), respectively. is there.

  In the general formula (A), the divalent linking group represented by Y2 has the same meaning as the divalent linking group represented by Y1 in the general formula (6).

  Further, in the general formula (A), as the 5-membered or 6-membered aromatic ring used for forming a group derived from a 5-membered or 6-membered aromatic ring represented by Y3 and Y4, respectively, Oxazole ring, thiophene ring, furan ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, diazine ring, triazine ring, imidazole ring, isoxazole ring, pyrazole ring, triazole ring and the like.

  Further, at least one of the groups derived from a 5-membered or 6-membered aromatic ring represented by Y3 and Y4 represents a group derived from an aromatic heterocycle containing a nitrogen atom as a ring constituent atom, Examples of the aromatic heterocycle containing a nitrogen atom as the ring constituent atom include an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a diazine ring, a triazine ring, an imidazole ring, an isoxazole ring, a pyrazole ring, Examples include a triazole ring.

(Preferred embodiment of the group represented by Y3)
In the general formula (A), the group represented by Y3 is preferably a group derived from the above 6-membered aromatic ring, and more preferably a group derived from a benzene ring.

(Preferred embodiment of the group represented by Y4)
In general formula (A), the group represented by Y4 is preferably a group derived from the 6-membered aromatic ring, more preferably an aromatic heterocycle containing a nitrogen atom as a ring constituent atom. Particularly preferably, Y4 is a group derived from a pyridine ring.

(Preferred embodiment of the group represented by the general formula (A))
A preferable embodiment of the group represented by the general formula (A) is represented by any one of the following general formulas (A-1), (A-2), (A-3), or (A-4). Groups.

  In the general formula (A-1), X represents —N (R) —, —O—, —S— or —Si (R) (R ′) —, and E1 to E8 represent —C (R1 ) = Or -N =, and R, R 'and R1 each represent a hydrogen atom, a substituent, or a linking site with Y1. Y2 represents a simple bond or a divalent linking group. E11 to E20 represent -C (R2) = or -N =, and at least one represents -N =. R2 represents a hydrogen atom, a substituent or a linking site. However, at least one of E11 and E12 represents -C (R2) =, and R2 represents a linking site. n2 represents an integer of 1 to 4. * Represents a linking site with Y1 in the general formula (6).

  In the general formula (A-2), X represents —N (R) —, —O—, —S— or —Si (R) (R ′) —, and E1 to E8 represent —C (R1 ) = Or -N =, and R, R 'and R1 each represent a hydrogen atom, a substituent, or a linking site with Y1. Y2 represents a simple bond or a divalent linking group. E21 to E25 represent -C (R2) = or -N =, and E26 to E30 represent -C (R2) =, -N =, -O-, -S- or -Si (R3) (R4)-. And at least one of E21 to E30 represents -N =. R2 represents a hydrogen atom, a substituent or a linking site, and R3 and R4 represent a hydrogen atom or a substituent. However, at least one of E21 or E22 represents -C (R2) =, and R2 represents a linking site. n2 represents an integer of 1 to 4. * Represents a linking site with Y1 in the general formula (6).

  In the general formula (A-3), X represents —N (R) —, —O—, —S— or —Si (R) (R ′) —, and E1 to E8 represent —C (R1 ) = Or -N =, and R, R 'and R1 each represent a hydrogen atom, a substituent, or a linking site with Y1. Y2 represents a simple bond or a divalent linking group. E31 to E35 represent -C (R2) =, -N =, -O-, -S- or -Si (R3) (R4)-, and E36 to E40 represent -C (R2) = or -N =. And at least one of E31 to E40 represents -N =. R2 represents a hydrogen atom, a substituent or a linking site, and R3 and R4 represent a hydrogen atom or a substituent. However, at least one of E32 or E33 is represented by -C (R2) =, and R2 represents a linking site. n2 represents an integer of 1 to 4. * Represents a linking site with Y1 in the general formula (6).

  In the general formula (A-4), X represents —N (R) —, —O—, —S— or —Si (R) (R ′) —, and E1 to E8 represent —C (R1 ) = Or -N =, and R, R 'and R1 each represent a hydrogen atom, a substituent, or a linking site with Y1. Y2 represents a simple bond or a divalent linking group. E41 to E50 represent -C (R2) =, -N =, -O-, -S-, or -Si (R3) (R4)-, and at least one represents -N =. R2 represents a hydrogen atom, a substituent or a linking site, and R3 and R4 represent a hydrogen atom or a substituent. However, at least one of E42 or E43 is represented by -C (R2) =, and R2 represents a linking site. n2 represents an integer of 1 to 4. * Represents a linking site with Y1 in the general formula (6).

  Hereinafter, the group represented by any one of the general formulas (A-1) to (A-4) will be described.

  In —N (R) — or —Si (R) (R ′) — represented by X in any of the groups represented by formulas (A-1) to (A-4), E1 to In -C (R1) = represented by E8, the substituents represented by R, R 'and R1 are each represented by -C (R3 represented by E51 to E66 and E71 to E88 in the general formula (1), respectively. ) = Synonymous with the substituent represented by R3.

  In any of the groups represented by the general formulas (A-1) to (A-4), the divalent linking group represented by Y2 is a divalent group represented by Y1 in the general formula (6). It is synonymous with the linking group.

  E11 to E20 of the general formula (A-1), E21 to E30 of the general formula (A-2), E31 to E40 of the general formula (A-3), E41 to E50 of the general formula (A-4), respectively. The substituent represented by R2 of —C (R2) ═ represented by the substitution represented by R3 of —C (R3) ═ represented by E51 to E66 and E71 to E88 in the general formula (1), respectively. Synonymous with group.

  Next, a further preferred embodiment of the compound represented by the general formula (6) according to the present invention will be described.

(Compound represented by the general formula (7))
In the present invention, among the compounds represented by the general formula (6), a compound represented by the following general formula (7) is preferable. The general formula (7) includes the general formula (1) shown as a compound constituting the nitrogen-containing layer 1a. Hereinafter, the compound represented by the general formula (7) will be described.

  In the general formula (7), Y5 represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof. E51 to E66 each represent -C (R3) = or -N =, and R3 represents a hydrogen atom or a substituent. Y6 to Y9 each represents a group derived from an aromatic hydrocarbon ring or a group derived from an aromatic heterocycle, and at least one of Y6 or Y7 and at least one of Y8 or Y9 is an aromatic group containing an N atom. Represents a group derived from a group heterocycle. n3 and n4 represent an integer of 0 to 4, but n3 + n4 is an integer of 2 or more.

  Y5 in General formula (7) is synonymous with Y5 in General formula (1).

  E51 to E66 in the general formula (7) have the same meanings as E51 to E66 in the general formula (1).

  In the general formula (7), as groups represented by E51 to E66, 6 or more of E51 to E58 and 6 or more of E59 to E66 are each represented by -C (R3) =. It is preferable.

  In the general formula (7), Y6 to Y9 are each an aromatic hydrocarbon ring used for forming a group derived from an aromatic hydrocarbon ring, such as a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an 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 ring, pyrene ring, pyranthrene ring, anthraanthrene ring, and the like.

  Furthermore, the aromatic hydrocarbon ring may have a substituent represented by R3 of -C (R3) = represented by E51 to E66 in the general formula (1).

  In the general formula (7), Y6 to Y9 are each an aromatic heterocycle used for forming a group derived from an aromatic heterocycle, for example, a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, or a pyridine ring. , Pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole Ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, diazacarbazole ring (one of the carbon atoms constituting the carboline ring is further substituted with a nitrogen atom) Shows the ring that is) It is below.

  Furthermore, the aromatic hydrocarbon ring may have a substituent represented by R3 of -C (R3) = represented by E51 to E66 in the general formula (1).

  In the general formula (7), an aromatic heterocycle containing an N atom used for forming a group derived from an aromatic heterocycle containing an N atom represented by at least one of Y6 or Y7 and at least one of Y8 or Y9. Examples of the ring include oxazole ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring. , Indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, diazacarbazole ring (carboline ring) Composing charcoal It shows a ring in which one atom is further substituted with a nitrogen atom), and the like.

  In general formula (7), the groups represented by Y7 and Y9 each preferably represent a group derived from a pyridine ring.

  In the general formula (7), the groups represented by Y6 and Y8 each preferably represent a group derived from a benzene ring.

  Among the compounds represented by the general formula (7) as described above, a more preferred embodiment is exemplified by the compound represented by the general formula (1) shown as the compound constituting the nitrogen-containing layer 1a.

  As specific examples of the compound represented by the general formula (6), (7), or general formula (1) as described above, the compounds (1 to 118) exemplified above are shown.

[Blocking layer: hole blocking layer, electron blocking layer]
The 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 a function of an electron transport layer 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 mentioned later can be used as a hole-blocking layer concerning this invention as needed. The hole blocking layer is preferably provided adjacent to the light emitting layer.

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

<Other components>
The organic electroluminescent element EL as described above has the purpose of reducing the resistance of the transparent electrode (for example, the first electrode 5 here) on the light extraction side, and the following auxiliary electrode is in contact with the first electrode 5. It may be provided. Further, for the purpose of preventing deterioration of the light emitting units 3-1, 3-2, and 3-3 configured using an organic material or the like, the substrate 11 is sealed with the following sealing material. Further, the following protective film or protective plate may be provided with the organic electroluminescent element EL and the sealing material sandwiched between the substrate 11 and the substrate 11.

[Auxiliary electrode]
The auxiliary electrode is provided as necessary for the purpose of reducing the resistance of the electrode having optical transparency (for example, the first electrode 5 and the transparent conductive layers 1b-1 and 1b-2 here). And in contact with the transparent conductive layers 1b-1 and 1b-2. The material for forming the auxiliary electrode 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. Examples of a method for forming such an auxiliary electrode 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 is preferably 50 μm or less from the viewpoint of the aperture ratio for extracting light, and the thickness of the auxiliary electrode is preferably 1 μm or more from the viewpoint of conductivity.

<Driving method of organic electroluminescent element EL>
When driving the organic electroluminescent element EL having the above-described configuration, three light emission elements are controlled by controlling the voltages applied to the first electrode 5, the second electrode 7, and the transparent conductive layers 1b-1 and 1b-2. The light emission in the units 3-1, 3-2, and 3-3 is controlled. Thereby, emitted light is extracted from the substrate 11 side with a desired color and brightness.

<Method for Producing Organic Electroluminescent Element EL>
First, the light transmissive first electrode 5 is formed as an anode on the substrate 11 by an appropriate film forming method such as vapor deposition or sputtering. In addition, before and after the formation of the first electrode 5, an auxiliary electrode pattern is formed as necessary.

  Next, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer are sequentially formed thereon to form a light emitting unit 3-1. The light emitting unit 3-1 is formed so as to obtain blue (B) emitted light hb by using a light emitting material (for example, a host compound and a light emitting dopant compound) appropriately selected in the formation of the light emitting layer.

The film formation of each of these layers includes spin coating, casting, ink jet, vapor deposition, sputtering, printing, etc., but it is easy to obtain a uniform film and it is difficult to generate pinholes. A vacuum deposition method or a spin coating method is particularly preferable. Further, different film forming 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, etc., but generally the boat heating temperature is 50 ° C. to 450 ° C., the degree of vacuum is 10 ⁻⁶ Pa to 10 ⁻² Pa, It is desirable to select each condition as appropriate within the range of a deposition rate of 0.01 nm / second to 50 nm / second, a substrate temperature of −50 ° C. to 300 ° C., and a film thickness of 0.1 μm to 5 μm.

  Next, the nitrogen-containing layer 1a-1 made of a compound containing nitrogen atoms is formed to a thickness of 1 μm or less, preferably 10 nm to 100 nm. Thereafter, the transparent conductive layer 1b-1 made of silver (or an alloy containing silver as a main component) is formed to have a thickness of 4 nm to 12 nm. These nitrogen-containing layer 1a and transparent conductive layer 1b can be formed by spin coating, casting, ink jetting, vapor deposition, sputtering, printing, etc., but it is easy to obtain a homogeneous film and has pinholes. The vacuum deposition method is particularly preferable from the viewpoint of difficulty in formation.

  Then, further, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer are formed in this order on the transparent conductive layer 1b-1 to form a light emitting unit 3-2. The light emitting unit 3-2 is formed so as to obtain green (G) emitted light hg by using a light emitting material (for example, a host compound and a light emitting dopant compound) appropriately selected in the formation of the light emitting layer. These layers are formed in the same manner as the light emitting unit 3-1.

  Next, a nitrogen-containing layer 1a-2 and a transparent conductive layer 1b-2 are formed in this order on the light emitting unit 3-2. These are formed in the same manner as the nitrogen-containing layer 1a-1 and the transparent conductive layer 1b-1.

  Thereafter, further, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer are sequentially formed on the transparent conductive layer 1b-2 to form a light emitting unit 3-3. This light emitting unit 3-3 is formed so that red (R) emitted light (hr) can be obtained by using a light emitting material (for example, a host compound and a light emitting dopant compound) appropriately selected in the formation of the light emitting layer. To do. These layers are formed in the same manner as the light emitting unit 3-1.

  After the above, the second electrode 7 is formed as a cathode on the light emitting unit 3-3 by an appropriate film forming method such as vapor deposition or sputtering.

  Thereby, the organic electroluminescent element EL is obtained. In the production of such an organic electroluminescent element EL, it is preferable to produce the light emitting unit 3-1 to the second electrode 7 consistently by a single evacuation, but the substrate 11 is taken out from the vacuum atmosphere in the middle. Different film forming methods may be applied. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

<Effect of organic electroluminescent element EL>
The organic electroluminescent element EL described above includes the transparent conductive layers 1b-1 and 1b-2 having both the conductivity and the light transmission described above between the light emitting units 3-1, 3-2 and 3-3. It is the structure clamped in. For this reason, the light emitting units 3-1, 3-2, 3-3 are injected with sufficient charges from the transparent conductive layers 1b-1, 1b-2 to ensure the light emission efficiency, and the light emitting units 3-1, , 3-2, and 3-3, by suppressing the absorption of the emitted light hb, hg, hr in the transparent conductive layers 1b-1, 1b-2, it is possible to improve the light emission efficiency. This also makes it possible to improve the light emission lifetime by reducing the drive voltage for obtaining a predetermined luminance.

≪3. Passive matrix display device using organic electroluminescence device >>
FIG. 3 is a schematic plan view for explaining the configuration of a passive matrix display device 10a using the above-described tandem organic electroluminescent element EL. FIG. 4 is a schematic cross-sectional view of the main part of the display device 10a, and corresponds to a cross section of three pixels in the horizontal direction in FIG. Hereinafter, the configuration of the display device 10a will be described with reference to these drawings. In addition, the same code | symbol is attached | subjected to the component similar to having demonstrated in FIG. 2, and the overlapping description is abbreviate | omitted.

<Panel Configuration of Display Device 10a>
The display device 10a shown in these drawings has a display region 13 on a main surface of a substrate 11 in which a plurality of pixels a provided with an organic electroluminescent element EL are two-dimensionally arranged. Peripheral circuits such as a vertical drive circuit 15 and a horizontal drive circuit 17 for driving the organic electroluminescent element EL, and a control circuit 19 for controlling these circuits are provided in the peripheral portion of the display area 13. ing. These peripheral circuits may be provided on an external substrate different from the substrate 11 on which the display region 13 is provided.

  Each organic electroluminescent element EL provided in each pixel a has the same configuration as described with reference to FIG. 2, for example. The first electrode 5 and the first light emitting unit 3 are sequentially arranged from the substrate 11 side. -1, nitrogen-containing layer 1a-1, transparent conductive layer 1b-1, second light emitting unit 3-2, nitrogen-containing layer 1a-2, transparent conductive layer 1b-2, third light emitting unit 3-3 , And the second electrode 7 are laminated in this order.

  Among these, the 1st electrode 5 is comprised, for example as a some electrode pattern extended in the perpendicular direction. The formation of the first electrode 5 is appropriately selected depending on the material used as the first electrode 5, and is formed by, for example, mask deposition or patterning of an electrode film using a resist pattern as a mask. These first electrodes 5 are connected to a horizontal drive circuit 17, and drive voltages Vy 1,... Vym are applied from the horizontal drive circuit 17.

  Each of the transparent conductive layers 1b-1 and 1b-2 and the second electrode 7 is configured as a plurality of electrode patterns extending in the horizontal direction, for example. These transparent conductive layers 1 b-1 and 1 b-2 and the second electrode 7 are provided so as to be stacked on each other at a position intersecting with the first electrode 5. The transparent conductive layers 1b-1, 1b-2 and the second electrode 7 are formed by mask vapor deposition, for example. The transparent conductive layers 1b-1, 1b-2 and the second electrode 7 are individually connected to the vertical drive circuit 15, and the drive voltages V1x1, V2x1, V3x1,. V2xn and V3xn are applied.

  The light emitting units 3-1, 3-2, 3-3 are formed as a continuous film between the first electrode 5, the transparent conductive layers 1b-1, 1b-2, and the second electrode 7. These light emitting units 3-1, 3-2, 3-3 need only be provided so as to cover the display area 13, and need not be patterned in the display area 13. For this reason, it is formed by mask deposition covering the first electrode 5 already formed in the lower layer and the terminal portions of the transparent conductive layers 1b-1 and 1b-2 as necessary.

<Sealing configuration of display device 10a>
In the display device 10a having the panel configuration as described above, a sealing material and a protective material, which are not shown here, are provided so as to cover the organic electroluminescent element EL. Next, the detail of a sealing material and a protective material is demonstrated.

[Encapsulant]
The sealing material is provided so as to cover the display region 13 in which the organic electroluminescent element EL is provided. Such a sealing material may be a plate-shaped (film-shaped) sealing member that is fixed to the substrate 11 side by an adhesive, or may be a sealing film. Further, this sealing material may be provided so as to cover the vertical drive circuit 15, the horizontal drive circuit 17, and further the control circuit 19 as necessary.

  Specific examples of the plate-like (film-like) sealing material include those composed of a glass substrate, a polymer substrate, and a metal material substrate, and these substrate materials are further thinned and flexibly bent. May be used.

  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. Further, examples of the metal material 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. .

  In particular, since the entire display device 10a can be thinned, a thin film-like polymer substrate or metal material substrate can be preferably used as the sealing material. However, when the organic electroluminescent element EL is one that extracts light also from the second electrode 7 side opposite to the substrate 11, a glass substrate or polymer substrate having optical transparency is used as the sealing material.

The polymer substrate made into 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, and conforms to JIS K 7129-1992. The water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by the method is preferably 1 × 10 ⁻³ g / (m ² · 24 h) or less. .

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

  Moreover, the adhesive for fixing such a plate-shaped sealing material to the substrate 11 side is a sealing agent for sealing the organic electroluminescence element EL sandwiched between the sealing material and the substrate 11. Used. Specifically, such adhesives include acrylic acid oligomers, photocuring and thermosetting adhesives having reactive vinyl groups of methacrylic acid oligomers, and moisture curable adhesives such as 2-cyanoacrylates. Mention may be made of adhesives.

  Examples of such an adhesive include epoxy-based heat and chemical curing types (two-component mixing). 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 organic electroluminescent element EL-1 may deteriorate with heat processing. For this reason, an adhesive that can be adhesively cured from room temperature to 80 ° C. is preferable. Further, a desiccant may be dispersed in the adhesive.

  Application | coating of the adhesive agent to the adhesion part of the sealing material and the board | substrate 11 may use commercially available dispenser, and may print it like screen printing.

  Further, when a gap is formed between the plate-shaped sealing material, the substrate 11, and the adhesive, the gap includes an inert gas such as nitrogen and argon, a fluorinated hydrocarbon, It is preferable to inject an inert liquid such as silicone oil. A vacuum is also possible. 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, it is important that the sealing film is provided in a state of completely covering the light emitting units 3-1, 3-2, and 3-3 in the organic electroluminescent element EL.

  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 entry of substances such as moisture and oxygen that cause deterioration of the light emitting units 3-1, 3-2, and 3-3 in the organic electroluminescent element EL-1. As such a material, for example, an inorganic material such as silicon oxide, silicon dioxide, or silicon nitride is used. Furthermore, in order to improve the brittleness of the sealing film, a laminated structure may be formed by using a film made of an organic material together with a film made of these inorganic materials.

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

  In addition, the sealing material mentioned above may be further provided with an electrode, and is configured to electrically connect the terminal portions of the first electrode 5 and the second electrode 7 of the organic electroluminescent element EL to this electrode. Also good.

[Protective film, protective plate]
The protective film or the protective plate is for mechanically protecting the organic electroluminescent element EL, and particularly when the sealing material is a sealing film, sufficient mechanical protection is provided for the organic electroluminescent element EL. Therefore, it is preferable to provide such a protective film or protective plate.

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

<Driving Method of Display Device 10a>
In driving the display device 10a having such a configuration, the horizontal drive circuit 17 controls the voltage application to the first electrodes 5 while the vertical drive circuit 15 controls the transparent conductive layers 1b-1, 1b-2, Each voltage corresponding to the display signal is applied to the second electrode 7. At this time, voltage application to the first electrode 5 is scanned by at least one of the horizontal drive circuit 17 and the vertical drive circuit 15, or voltage application to the transparent conductive layers 1 b-1 and 1 b-2 and the second electrode 7 is performed. To scan.

  Thus, application to the first electrode 5, the transparent conductive layers 1b-1, 1b-2, and the second electrode 7 in the organic electroluminescence element EL of each pixel a arranged in the selected vertical direction or horizontal direction. The emitted lights hb, hg, hr are generated with a desired color and brightness according to the voltage, and these emitted lights hb, hg, hr are extracted from the substrate 11 side.

<Effect of display device 10a>
As described with reference to FIG. 2, the display device 10 a configured as described above includes the transparent conductive layers 1 b-1 and 1 b-2 having both conductivity and light transmittance, and the light emitting units 3-1 and 3-1. It is configured using an organic electroluminescent element EL sandwiched between 3-2 and 3-3. That is, the display device 10a emits each light emission while sufficiently injecting charges from the transparent conductive layers 1b-1 and 1b-2 to the light emitting units 3-1, 3-2, and 3-3 to ensure the light emission efficiency. Luminous efficiency was improved by suppressing absorption in the transparent conductive layers 1b-1 and 1b-2 of the emitted lights hb, hg and hr generated by the units 3-1, 3-2 and 3-3. It is comprised by the organic electroluminescent element EL. Therefore, the controllability of the color tone is improved without reducing the light extraction efficiency from the light emitting units 3-1, 3-2, 3-3 stacked in the tandem organic electroluminescent element EL. In the display device 10a using the organic electroluminescent element EL, it is possible to perform display with high brightness and good color reproducibility.

<< 4. Active matrix display device using organic electroluminescence device >>
FIG. 5 is a schematic plan view for explaining the configuration of an active matrix display device 10b using the above-described tandem organic electroluminescent element EL. FIG. 6 is a schematic cross-sectional view of the main part of the display device 10b, which corresponds to the cross section of three pixels in the horizontal direction in FIG. Hereinafter, the configuration of the display device 10b will be described based on these drawings. In addition, the same code | symbol is attached | subjected to the component similar to having demonstrated in FIG. 2, and the overlapping description is abbreviate | omitted.

<Panel Configuration of Display Device 10b>
A display device 10b shown in these drawings has a display region 13 on a main surface of a substrate 11 in which a plurality of pixels a provided with organic electroluminescent elements EL are two-dimensionally arranged. Peripheral circuits such as a vertical drive circuit 15 and a horizontal drive circuit 17 for driving the organic electroluminescent element EL, and a control circuit 19 for controlling these circuits are provided in the peripheral portion of the display area 13. ing. These peripheral circuits may be provided on an external substrate different from the substrate 11 on which the display region 13 is provided.

  A plurality of scanning lines 21 are wired in the display area 13 in the horizontal direction. These scanning lines 21 are connected to the vertical drive circuit 15. The display area 13 is provided with a plurality of signal line sets each including three signal lines 23-1, 23-2, and 23-3 in the vertical direction. These signal lines 23-1, 23-2, 23-3 are connected to the horizontal drive circuit 17. The pixel a is arranged at each intersection of the scanning line 21 and the signal lines 23-1, 23-2, 23-3.

  Each organic electroluminescent element EL provided in each pixel a has the same configuration as described with reference to FIG. 2, for example. The first electrode 5 and the first light emitting unit 3 are sequentially arranged from the substrate 11 side. -1, nitrogen-containing layer 1a-1, transparent conductive layer 1b-1, second light emitting unit 3-2, nitrogen-containing layer 1a-2, transparent conductive layer 1b-2, third light emitting unit 3-3 , And the second electrode 7 are laminated in this order.

  Among these, the 1st electrode 5 is arrange | positioned in the state of the continuous film in all the pixels a as a common electrode which covers the display area 13. FIG. The formation of the first electrode 5 is appropriately selected depending on the material used for the first electrode 5. When patterning is necessary, for example, mask deposition covering an unnecessary portion or a resist pattern is used as a mask. It is formed by patterning the electrode film. For example, a fixed voltage V is applied to the first electrode 5.

  On the other hand, each of the transparent conductive layers 1b-1, 1b-2 and the second electrode 7 is provided as a pixel electrode patterned for each pixel a, and is laminated in each pixel a. The transparent conductive layers 1b-1, 1b-2 and the second electrode 7 are formed by mask vapor deposition, for example.

  The light emitting units 3-1, 3-2, 3-3 are formed as a continuous film between the first electrode 5, the transparent conductive layers 1b-1, 1b-2, and the second electrode 7. These light emitting units 3-1, 3-2, 3-3 need only be provided so as to cover the display area 13, and need not be patterned in the display area 13. For this reason, it forms by mask vapor deposition which covered the unnecessary part.

  From each scanning line 21, three branch wirings 21-1, 21-2, and 21-3 are branched and provided corresponding to one pixel a. Among these, each branch wiring 21-1 is connected to the transparent conductive layer 1b-1 in the corresponding pixel a. Each branch line 21-2 is connected to the transparent conductive layer 1b-2 in the corresponding pixel a. Each branch line 21-3 is connected to the second electrode 7 in the corresponding pixel a.

  Further, the branch wiring 21-1 of each pixel a arranged along this is connected to each signal line 23-1. In addition, each signal line 23-2 is connected to a branch wiring 21-2 of each pixel a arranged along the signal line 23-2. Each signal line 23-3 is connected to a branch wiring 21-3 of each pixel a arranged along the signal line 23-3.

  As shown in FIG. 6, the scanning line 21, the branch wirings 21-1, 21-2, 21-3, and the signal lines 23-1, 23-2, 23-3 cover the organic electroluminescent element EL. It is assumed that the wiring is formed on the substrate 11 while being insulated from each other by the provided insulating films 25 and 27. These insulating films 25 and 27 are preferably films having good sealing properties such as a silicon nitride film.

  The formation of the scanning line 21, the branch wirings 21-1, 21-2, 21-3, and the signal lines 23-1, 23-2, 23-3 is appropriately selected depending on the material used for the first electrode 5. For example, it is formed by mask vapor deposition or patterning of an electrode film using a resist pattern as a mask. Further, the branch wirings 21-1, 21-2, 21-3, the signal lines 23-1, 23-2, 23-3, the transparent conductive layers 1b-1, 1b-2, and the second electrode 7 are mutually connected. The vias 29 are formed by embedding a conductive material in connection holes formed in the insulating films 25 and 27 and the light emitting units 3-2 and 3-3. However, the step after forming the light emitting unit 3-3 is preferably performed by a low temperature process.

  As described above, the transparent conductive layers 1b-1 and 1b-2 and the second electrode 7 configured as pixel electrodes are each connected to the vertical drive circuit 15 via the scanning line 21 and the signal line 23-1. , 23-2, 23-3, and is connected to the horizontal drive circuit 17.

<Sealing configuration of display device 10b>
In the display device 10b having the panel configuration as described above, similarly to the display device 10a described above with reference to FIGS. 3 and 4, the display device 10b is sealed with a sealing material, and further, if necessary, a protective film or It shall be protected using a protective plate.

<Driving Method of Display Device 10b>
In driving the display device 10 b having such a configuration, a common fixed voltage V is applied to the first electrode 5. In this state, the horizontal drive circuit 17 sends a signal line 23-to the transparent conductive layers 1 b-1 and 1 b-2 and the second electrode 7 provided in each pixel a of the row selected by the vertical drive circuit 15. Each voltage according to the display signal is applied via 1, 23-2, 23-3. As a result, emitted light hb, hg, hr is generated in a desired color and brightness according to the voltage applied to the transparent conductive layers 1b-1, 1b-2 and the second electrode 7, and these emitted light from the substrate 11 side. Lights hb, hg, and hr are extracted.

<Effect of display device 10b>
As described with reference to FIG. 2, the display device 10 b configured as described above includes the transparent conductive layers 1 b-1 and 1 b-2 having both conductivity and light transmission, and the light emitting units 3-1 and 3-1. It is configured using an organic electroluminescent element EL sandwiched between 3-2 and 3-3. Therefore, similarly to the display device 10a described above, it is possible to perform display with high brightness and good color reproducibility.

≪5. Other active matrix type display devices using organic electroluminescent elements >>
FIG. 7 is a schematic cross-sectional view of three pixels for explaining the configuration of another active matrix display device 10c using the above-described organic electroluminescent element EL having a tandem structure. Hereinafter, the configuration of the display device 10c will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the component similar to having demonstrated in FIG. 2, and the overlapping description is abbreviate | omitted.

<Panel Configuration of Display Device 10c>
A display device 10c shown in these drawings has a display region 13 on a main surface of a substrate 11 in which a plurality of pixels a provided with an organic electroluminescent element EL are two-dimensionally arranged. In the peripheral portion of the display area 13, there are provided peripheral circuits such as a vertical drive circuit and a horizontal drive circuit (not shown here), and a control circuit for controlling these circuits. These peripheral circuits may be provided on an external substrate different from the substrate 11.

  Each pixel a on the substrate 11 is provided with a pixel circuit configured using a thin film transistor Tr. These pixel circuits are connected to a scanning line not shown here and a signal line extending in a direction perpendicular to the scanning line. Each scanning line is connected to the vertical drive circuit described above. On the other hand, each signal line is connected to the horizontal drive circuit described above. Pixel circuits, scanning lines, and signal lines using these thin film transistors Tr are covered with an interlayer insulating film 31.

  Each organic electroluminescent element EL is disposed in each pixel a on the interlayer insulating film 31. Each organic electroluminescent element EL provided in each pixel a has the same configuration as described with reference to FIG. 2, for example. The first electrode 5 and the first light emitting unit 3 are sequentially arranged from the substrate 11 side. -1, nitrogen-containing layer 1a-1, transparent conductive layer 1b-1, second light emitting unit 3-2, nitrogen-containing layer 1a-2, transparent conductive layer 1b-2, third light emitting unit 3-3 , And the second electrode 7 are laminated in this order.

  Among these, the first electrode 5 and the transparent conductive layers 1b-1 and 1b-2 are each provided as a pixel electrode patterned for each pixel a, and are stacked in each pixel a. The formation of the first electrode 5 is appropriately selected depending on the material used as the first electrode 5, and is formed by, for example, mask deposition or patterning of an electrode film using a resist pattern as a mask. The transparent conductive layers 1b-1 and 1b-2 are formed by, for example, mask vapor deposition. The first electrode 5 and the transparent conductive layers 1b-1 and 1b-2 are individually connected to the thin film transistor Tr constituting the pixel circuit. Thus, the first electrode 5 and the transparent conductive layers 1b-1 and 1b-2 are connected to the peripheral circuit via the pixel circuit, the scanning line, and the signal line.

  On the other hand, the second electrode 7 is arranged as a common electrode covering the display area 13 in a continuous film state in all the pixels a. The formation of the second electrode 7 is appropriately selected depending on the material used as the first electrode 5. When patterning is necessary, for example, mask deposition covering an unnecessary portion or a resist pattern is used as a mask. It is formed by patterning the electrode film. For example, a fixed voltage V is applied to the second electrode 7.

  The light emitting units 3-1, 3-2, 3-3 are formed as a continuous film between the first electrode 5, the transparent conductive layers 1b-1, 1b-2, and the second electrode 7. These light emitting units 3-1, 3-2, 3-3 need only be provided so as to cover the display area 13, and need not be patterned in the display area 13. For this reason, it forms by mask vapor deposition which covered the unnecessary part.

  Each thin film transistor Tr is connected to the first electrode 5 and the transparent conductive layers 1b-1 and 1b-2 by a conductive material in the connection holes formed in the light emitting units 3-2 and 3-1, and the interlayer insulating film 31. It is assumed that it is made by the via 33 formed by embedding with.

  As described above, each of the first electrode 5 and the transparent conductive layers 1b-1 and 1b-2 configured as the pixel electrode is in a state of being connected to the thin film transistor Tr configuring the pixel circuit.

<Sealing configuration of display device 10c>
In the display device 10c having the panel configuration as described above, similarly to the display device 10a described above with reference to FIGS. 3 and 4, the display device 10c is sealed using a sealing material, and further, a protective film or It shall be protected using a protective plate.

<Driving Method of Display Device 10c>
In driving the display device 10 c having such a configuration, a common fixed voltage V is applied to the second electrode 7. In this state, a pixel circuit is selected by the peripheral drive circuit, and each voltage corresponding to the display signal is applied to the first electrode 5 connected to the selected pixel circuit and the transparent conductive layers 1b-1 and 1b-2. To do. As a result, emitted light hb, hg, hr is generated with a desired color and brightness according to the voltage applied to the first electrode 5 and the transparent conductive layers 1b-1, 1b-2, and these emitted light from the substrate 11 side. Lights hb, hg, and hr are extracted.

<Effect of display device 10c>
As described with reference to FIG. 2, the display device 10 c configured as described above includes the transparent conductive layers 1 b-1 and 1 b-2 having both conductivity and light transmittance, and the light emitting units 3-1 and 3-1. It is configured using an organic electroluminescent element EL sandwiched between 3-2 and 3-3. Therefore, similarly to the display device 10a described above, it is possible to perform display with high brightness and good color reproducibility.

≪6. Modification 1 >>
In the embodiment of each display device described above, as described with reference to FIG. 2 as an example, the nitrogen-containing layers 1a-1 and 1a-2 and the transparent conductive layer described with reference to FIG. The configuration to which the organic electroluminescent element EL provided with 1b-1 and 1b-2 is applied has been described. However, the organic electroluminescent element used in each display device may further use the transparent conductive layer 1b adjacent to the nitrogen-containing layer 1a described with reference to FIG. 1 as the first electrode 5 on the light extraction side. In this case, the nitrogen-containing layer 1a is provided on the substrate 11 side, and the transparent conductive layer 1b is disposed adjacent to the upper portion.

  Furthermore, if the organic electroluminescent element used for the display device has a top emission structure that extracts emitted light hb, hg, hr from the opposite side to the substrate 11, the structure described with reference to FIG. As the second electrode 7 provided, the transparent conductive layer 1b adjacent to the nitrogen-containing layer 1a described with reference to FIG. 1 may be used. In this case, the nitrogen-containing layer 1a is provided on the light emitting unit 3-3 side, and the transparent conductive layer 1b is disposed adjacent to the upper portion. For this reason, this nitrogen-containing layer 1a is preferably formed as a layer having characteristics suitable for the light emitting unit 3-3 (for example, electron transporting property). Also, with such a configuration, the light emitting unit 3-1 closer to the substrate 11 is set so that the wavelength of the emitted light becomes longer, so that the emission side of the blue (B) emitted light hb has a higher emission side. The constituent material of the light emitting layer in the green (G) light emitting unit 3-2 and the red (R) light emitting unit 3-3 disposed in the substrate can be prevented from being excited, and the light emitting color having good controllability can be emitted. Can be obtained from the second electrode 7 side.

  Further, both the first electrode 5 and the second electrode 7 may be organic electroluminescent elements that emit light on both sides by using the transparent conductive layer 1b adjacent to the nitrogen-containing layer 1a described with reference to FIG. .

≪7. Modification 2 >>
In the embodiments of the display devices described above, as described with reference to FIG. 2 as an example, an organic electroluminescent element EL in which three light emitting units 3-1, 3-2, and 3-3 are stacked is used. Explained the configuration that was. However, the organic electroluminescent element used in each display device may have a configuration in which a fourth light emitting unit is further stacked, or a configuration in which two light emitting units are stacked.

  When four layers of light emitting units are stacked, in addition to the blue (B) light emitting unit 3-1, the green (G) light emitting unit 3-2, and the red (R) light emitting unit 3-3, white A light emitting unit capable of obtaining the emitted light of (W) is used. Such a white (W) light-emitting unit extracts light further than the blue (B) light-emitting unit 3-1 through the transparent conductive layer 1b adjacent to the nitrogen-containing layer 1a described with reference to FIG. It is preferable to provide on the side.

  On the other hand, if only two light emitting units are laminated, the transparent conductive layer 1b in which the two light emitting units having different selected emission wavelengths are adjacent to the nitrogen-containing layer 1a described with reference to FIG. It suffices to stack them. According to such a configuration, a display device capable of color display is obtained.

≪Preparation of transparent conductive layer≫
As described below, each of the transparent conductive layers of Samples 101 to 112 was fabricated such that the area of the conductive region was 5 cm × 5 cm.

  In Sample 101, a transparent conductive layer having a thickness of 5 nm using silver was formed as a single layer. In samples 102 to 112, a nitrogen-containing layer composed of each compound was formed, and a transparent conductive layer having a thickness of 5 nm using silver was formed adjacent to the upper part.

  In the production of the transparent conductive layer of the sample 102, a layer using anthracene (compound No. 01) containing no nitrogen as a compound was formed instead of the nitrogen-containing layer serving as the base.

  On the other hand, in the production of each of the transparent conductive layers of Samples 103 to 112, compounds No. 02 to No. 11 containing nitrogen as shown below were used as compounds constituting the nitrogen-containing layer. Among these compounds, compounds No. 03 and No. 08 are compounds included in the general formula (1), and compound No. 08 is compound 10. Compound No. 11 is a compound included in the general formula (2).

  Table 1 below shows the number of nitrogen atoms [n] and silver (Ag) in the compound that stably binds to silver (Ag) for each of compounds No. 02 to No. 11 used in Samples 103 to 112. And the interaction energy [ΔE] of nitrogen (N) in the compound, the surface area [s] of the compound, and the effective action energy [ΔEef] calculated from these. The dihedral angle [D] and [ΔE] formed by the nitrogen atom and silver with respect to the ring containing the nitrogen atom in the compound for obtaining [n] are Gaussian 03 (Gaussian, Inc., Wallingford, CT , 2003). In addition, in each compound No.02-No.11 used by these samples 103-112, the nitrogen atom which is the range of dihedral angle D <10 degree was counted to several [n].

  In Compound No. 02, the effective energy [ΔEef] indicating the relationship between the nitrogen atom (N) contained in the compound and silver (Ag) constituting the transparent conductive layer is ΔEef> −0.1. On the other hand, the compounds No. 03 to No. 11 satisfy ΔEef ≦ −0.1.

<Procedure for Producing Transparent Conductive Layer of Sample 101>
First, a transparent alkali-free glass substrate was fixed to a substrate holder of a commercially available vacuum deposition apparatus and attached to a vacuum tank of the vacuum deposition apparatus. Moreover, silver (Ag) was put into the resistance heating boat made from tungsten, and it attached in the said vacuum chamber. Next, after depressurizing the vacuum tank to 4 × 10 ⁻⁴ Pa, the resistance heating boat is energized and heated, and the deposition rate is 0.1 nm / second to 0.2 nm / second, and the transparent film is made of silver with a film thickness of 5 nm. A conductive layer was formed on the substrate.

<Procedure for Producing Transparent Conductive Layers of Samples 102-112>
A transparent non-alkali glass substrate was fixed to a substrate holder of a commercially available vacuum deposition apparatus. Moreover, in preparation of each transparent conductive layer, said each compound No.01-No.11 was put into the resistance heating boat made from a tantalum. These substrate holder and heating boat were attached to the first vacuum chamber of the vacuum deposition apparatus. Moreover, silver (Ag) was put into the resistance heating boat made from tungsten, and it attached in the 2nd vacuum chamber.

In this state, first, the first vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa, and then heated by energizing a heating boat containing each compound, at a deposition rate of 0.1 nm / second to 0.2 nm / second. A nitrogen-containing layer composed of each compound having a film thickness of 25 nm was provided on the substrate.

Next, the base material formed up to the nitrogen-containing layer is transferred to the second vacuum chamber while maintaining a vacuum, and after the pressure in the second vacuum chamber is reduced to 4 × 10 ⁻⁴ Pa, the heating boat containing silver is energized and heated. did. Thus, a transparent conductive layer made of silver having a film thickness of 5 nm was formed at a deposition rate of 0.1 nm / second to 0.2 nm / second, and the transparent conductive layers of the samples 102 to 112 were formed adjacent to the nitrogen-containing layer. Obtained.

<Evaluation of Samples in Examples>
The sheet resistance value was measured about each transparent conductive layer of the samples 101-112 produced above. The sheet resistance value was measured by a four-probe constant current application method using a resistivity meter (MCP-T610 manufactured by Mitsubishi Chemical Corporation). The results are shown in Table 1 above.

<Evaluation results of examples>
As apparent from Table 1, the transparent conductive layers of the samples 104 to 112 adjacent to the nitrogen-containing layer using the compounds No. 03 to No. 11 having an effective action energy ΔEef of ΔEef ≦ −0.1 are 5 nm. Although it is an extremely thin film, it is possible to measure the sheet resistance value, and it is confirmed that the film is formed with a substantially uniform film thickness by single-layer growth type (FW type) film growth. It was. On the other hand, the transparent conductive layer of Sample 101 having a single layer structure without a nitrogen-containing layer, the transparent conductive layer of Sample 102 provided adjacent to the underlayer of Compound No. 1 that does not contain nitrogen, and ΔEef> The transparent conductive layer of Sample 103 adjacent to the nitrogen-containing layer using Compound No. 02 that is −0.1 cannot measure sheet resistance.

  FIG. 8 shows the relationship between the effective action energy ΔEef for the compounds No. 03 to No. 11 constituting the nitrogen-containing layer and the sheet resistance measured for each transparent conductive layer adjacent thereto. From FIG. 8, it is apparent that the sheet resistance of the transparent conductive layer tends to decrease as the value of ΔEef decreases in the range where the effective action energy ΔEef is confirmed to be −0.5 ≦ ΔEef ≦ −0.1. Further, when the effective action energy ΔEef is in the range of −0.5 ≦ ΔEef ≦ −0.2, it is more preferable that the sheet resistance is maintained at 1000 [Ω / □] or less.

  From the above, it was confirmed that a transparent conductive layer having a low resistance despite being a thin film can be obtained by selecting and using a compound constituting the nitrogen-containing layer using the effective action energy ΔEef as an index. It was.

  1a-1, 1a-2 ... nitrogen-containing layer, 1b-1, 1b-2 ... transparent conductive layer, 3-1, 3-2, 3-3 light emitting unit, 5 ... first electrode, 7 ... second electrode, 15 ... Vertical drive circuit, 17 ... Horizontal drive circuit

Claims (7)

A pair of electrodes;
A plurality of light emitting units each having a light emitting layer of a different light emission color configured using an organic material, and arranged in an overlapping manner between the electrodes;
Composed of silver or a silver-based alloy, and a transparent conductive layer disposed between the light emitting units;
Comprising a compound containing a nitrogen atom, and comprising a nitrogen-containing layer disposed adjacent to the transparent conductive layer between the transparent conductive layer and the light emitting unit ,
Each of the light emitting units has at least a hole injection layer, a hole transport layer, the light emitting layer, an electron transport layer, and an electron injection layer,
The compound which comprises the said nitrogen containing layer is a display apparatus with which effective action energy (DELTA) Eef with silver represented by following formula (1) satisfy | fills following formula (2) .
The compound includes a compound represented by the following general formula (1)
The display device according to claim 1 .
[In General Formula (1), Y5 represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof.
E51 to E66 and E71 to E88 each represent -C (R3) = or -N =, and R3 represents a hydrogen atom or a substituent.
At least one of E71 to E79 and at least one of E80 to E88 represent -N =. n3 and n4 represent an integer of 0 to 4, but n3 + n4 is an integer of 2 or more. ] The compound includes a compound represented by the following general formula (2)
The display device according to claim 1 .
[However, in General Formula (2), at least one of T11 and T12 is a nitrogen atom, at least one of T21 to T25 is a nitrogen atom, and at least one of T31 to T35 is a nitrogen atom. .
R represents a substituent. ] Wherein the plurality of light emitting units, the light emitting unit emits blue light beam is obtained, a green light-emitting unit emitting light can be obtained, and red emission light is a light emitting unit obtained according to any one of claims 1 to 3 Display device. One of the pair of electrodes is configured as a transparent electrode on the light extraction side,
The display device according to any one of claims 1 to 4 , wherein the plurality of light emitting units has a shorter emission wavelength as being arranged closer to the light extraction side. One of the pair of electrodes is configured as a plurality of electrode patterns extending in one direction,
Each of the other of the pair of electrodes and the transparent conductive layer is configured as a plurality of electrode patterns extending in the other direction intersecting the one direction,
The light emitting unit, a display device according to any one of claims 1-5, which is formed as a continuous film between the transparent conductive layer and the pair of electrodes. One of the pair of electrodes and the transparent conductive layer are configured as a plurality of pixel electrodes,
The other of the pair of electrodes is disposed to be opposed to the plurality of pixel electrodes as a common electrode,
The light emitting unit is formed as a continuous film between the plurality of pixel electrodes and the common electrode.
The display device according to any one of claims 1 to 5 .