JP2016219126A - Transparent electrode and organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent electrode suppressed in voltage fluctuations and luminance fluctuations with the lapse of time.SOLUTION: A transparent electrode of the present invention includes a conductive layer and at least one layer of an intermediate layer provided to be adjacent to the conductive layer. The conductive layer contains silver and an element selected from among oxygen, sulfur, bromine, chloride and iodine, as a trace element.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transparent electrode and an organic electroluminescence element. In particular, the present invention relates to a transparent electrode in which voltage fluctuation and luminance fluctuation with time are suppressed, and an organic electroluminescence element including the transparent electrode.

  An organic EL element (also referred to as organic electroluminescence, organic LED, or OLED) using electroluminescence of an organic material having conductivity is a low voltage of about several V to several tens V. It is a thin-film, completely solid-state device capable of emitting a large amount of light, and has excellent characteristics such as high brightness, high light emission efficiency, thinness, light weight, surface light emission, wide viewing angle, and flexibility. For this reason, it has been attracting attention in recent years as surface light emitters such as backlights for various displays, display boards such as signboards and emergency lights, and illumination light sources.

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

As the transparent electrode, generally metal oxide semiconductor based material are well known, indium tin oxide is particularly indium tin oxide _{(SnO 2 -In 2 O 3:} Indium Tin Oxide: ITO) is It is often used, and studies aiming at lowering resistance by laminating ITO and silver have been made (for example, see Patent Documents 1 and 2). However, ITO uses indium, which is a rare metal, and therefore has a high material cost. In order to reduce resistance, it is necessary to perform heat treatment at about 300 ° C. after film formation, which damages organic materials and resins used as flexible substrates. May give.

  Therefore, a technique for achieving both light transmittance and conductivity by forming a thin film using an alloy of silver (Ag) and magnesium (Mg) having high electrical conductivity (see, for example, Patent Document 3). Etc. have been proposed. However, the resistance value of the electrode disclosed in Patent Document 3 is at most about 100Ω / □, which is insufficient as the conductivity of the electrode. In addition, since magnesium is easily oxidized, there is a problem that deterioration with time is remarkable. there were.

  On the other hand, a technique related to an organic EL element in which silver is deposited as a cathode at a thickness of 15 nm has been proposed (see, for example, Patent Document 4). However, in the silver film disclosed in Patent Document 4, when the film is thinned, it is difficult to maintain the electrode characteristics because silver easily migrates.

For this, a method of suppressing the silver migration by providing an intermediate layer such as an organic substance between the substrate and the electrode is conceivable. However, even an electrode manufactured in this way has a large voltage / luminance change over time, and it may be difficult to maintain required electrode characteristics.
The inventors diligently studied that the deterioration of the electrode characteristics over time is due to the influence of outgas from residual oxygen, residual moisture, grease, etc. in the vacuum environment during film formation, and the outside air after the device is manufactured. This is considered to be due to the effects of contamination. In particular, the residual components in the apparatus are generated due to the performance of the vacuum pump, the chamber during vapor deposition, the material boat, the outgas emitted from the crucible, and the like, and it is difficult to strictly control this.

JP 2002-015623 A Japanese Unexamined Patent Publication No. 2006-164961 JP 2006-344497 A US Patent Application Publication No. 2011/0260148

  The present invention has been made in view of the above problems and situations, and a solution to the problem is to provide a transparent electrode in which voltage fluctuation and luminance fluctuation with time are suppressed, and an organic electroluminescence device including the transparent electrode. It is.

As a result of examining the cause of the above-mentioned problem in order to solve the above-mentioned problem according to the present invention, the transparent electrode comprises a conductive layer and at least one intermediate layer provided adjacent to the conductive layer, It has been found that when the conductive layer contains silver and a predetermined element as a trace element, voltage fluctuation and luminance fluctuation with time can be suppressed.
That is, the subject concerning this invention is solved by the following means.

1. A conductive layer, and at least one intermediate layer provided adjacent to the conductive layer,
The said conductive layer contains silver and the element chosen from oxygen, sulfur, bromine, chlorine, and iodine as a trace amount element, The transparent electrode characterized by the above-mentioned.

  2. 2. The transparent electrode according to item 1, wherein the conductive layer contains the trace element in an amount of 1% by mass or less.

  3. 3. The transparent electrode according to item 1 or 2, wherein the conductive layer contains 0.001 to 0.5% by mass of the trace element.

  4). 4. The transparent electrode according to any one of items 1 to 3, wherein the conductive layer contains 0.001 to 0.1% by mass of the trace element.

  5. An organic electroluminescence device comprising the transparent electrode according to any one of items 1 to 4.

ADVANTAGE OF THE INVENTION According to this invention, the organic electroluminescent element provided with the transparent electrode by which the voltage fluctuation and brightness | luminance fluctuation | variation with time were suppressed, and this transparent electrode can be provided.
The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
Unlike a metal oxide semiconductor such as ITO, a pure silver electrode is easily transformed into an oxide, sulfide, or the like when its surface reacts with oxygen, sulfur, or the like. For this reason, it is presumed that an electrode made of pure silver is likely to cause voltage fluctuation and luminance fluctuation over time, which was not seen with an ITO electrode. That is, it is considered that the luminance changes in accordance with the change in voltage due to the change in the amount of electrons or holes injected over time after energization due to the change in the electrode.
In the present invention, the conductive layer contains silver and an element selected from oxygen, sulfur, bromine, chlorine and iodine as trace elements in advance, thereby causing contamination by residual gas and outgas in the apparatus. It is estimated that the change to the injection amount of electrons or holes is reduced, and as a result, the performance of the device is not deteriorated and the stability is improved.
In addition, it is presumed that the surface contamination of the electrode over time is the main factor of the voltage / brightness variation from the result that the state in which the trace element is present on the surface has less voltage / brightness variation and higher stability. Therefore, it is considered that the fluctuation rate of the film quality can be reduced by preliminarily contaminating the electrode surface by containing trace elements in the surface.

Schematic sectional view showing an example of the transparent electrode of the present invention Schematic sectional view showing an example of the organic EL device of the present invention

The transparent electrode of the present invention comprises a conductive layer and at least one intermediate layer provided adjacent to the conductive layer, and the conductive layer contains silver and oxygen, sulfur as a trace element, And an element selected from bromine, chlorine and iodine. This feature is a technical feature common to or corresponding to each of claims 1 to 5.
In the present invention, it is preferable that the conductive layer contains 1% by mass or less of the trace amount element in order to express the effect of the present invention.
Moreover, in this invention, when expressing the effect of this invention, it is preferable that the said electroconductive layer contains the said trace amount containing element 0.001-0.5 mass%.
Moreover, in this invention, when expressing the effect of this invention, it is preferable that the said electroconductive layer contains the said trace amount containing element 0.001-0.1 mass%.
Moreover, the organic electroluminescent element of this invention is equipped with the transparent electrode of this invention, It is characterized by the above-mentioned.

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

<Outline of transparent electrode>
As shown in FIG. 1, the transparent electrode 10 of the present invention includes a conductive layer 1b and at least one intermediate layer 1a provided adjacent to the conductive layer 1b, and the conductive layer 1b is made of silver. And an element selected from oxygen, sulfur, bromine, chlorine and iodine as a trace element. In addition, the transparent electrode 10 of the present invention is preferably provided on the transparent substrate 11, and in that case, the surface of the intermediate layer 1 a opposite to the conductive layer 1 b is disposed so as to face the transparent substrate 11. The
In addition, the transparency of the transparent electrode and transparent substrate of this invention means that the light transmittance in wavelength 550nm is 50% or more.

  The transparent electrode 10 may be covered with a protective film in a state where the conductive layer 1b and the intermediate layer 1a are sandwiched between the transparent substrate 11 and a conductive layer different from the conductive layer 1b. May be further laminated. In this case, it is preferable that the protective film has light transmittance so as not to impair the light transmittance of the transparent electrode 10.

<Transparent substrate>
The transparent substrate is composed of a substrate material having optical transparency, and examples thereof include glass, quartz, and a transparent resin film, but are not limited thereto.

  Examples of the glass include silica glass, soda-lime silica glass, lead glass, borosilicate glass, and alkali-free glass. The surface of these glass materials may be subjected to physical treatment such as polishing, if necessary, from the viewpoint of adhesion with the intermediate layer, durability and smoothness, and is made of an inorganic or organic material. A film or a hybrid film combining these films may be formed.

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

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

  The material for forming the gas 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, etc. Can be used. Furthermore, in order to improve the brittleness of the gas 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 gas barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used, but the method based on the atmospheric pressure plasma polymerization method described in JP-A-2004-68143 is particularly preferable.

  The transparent substrate preferably has an average transmittance of light having a wavelength of 450 to 800 nm of 70% or more, more preferably 80% or more, and further preferably 85% or more. When the average light transmittance of the transparent substrate is low, the average light transmittance of the entire transparent electrode is lowered. Moreover, it is preferable that the average absorption factor of the light with a wavelength of 450-800 nm of a transparent substrate is 10% or less, More preferably, it is 5% or less, More preferably, it is 3% or less.

  The average transmittance of the transparent substrate is a value measured by allowing measurement light to enter from an angle inclined by 5 ° with respect to the front surface of the transparent substrate. On the other hand, the average absorptance is a value calculated as [average absorptance = 100− (average transmittance + average reflectance)] by measuring the average reflectance of the transparent substrate in the same manner as the average transmittance. Average transmittance and average reflectance are measured with a spectrophotometer.

  The refractive index of the transparent substrate is preferably 1.40 to 1.95, more preferably 1.45 to 1.75, and still more preferably 1.45 to 1.70. The refractive index of the transparent substrate is usually determined by the material of the transparent substrate. The refractive index of the transparent substrate is the refractive index of light having a wavelength of 510 nm, and is measured with an ellipsometer.

  The thickness of the transparent substrate is preferably 1 μm to 20 mm, more preferably 10 μm to 2 mm. When the thickness of the transparent substrate is greater than 1 μm, the strength of the transparent substrate is increased, and damage is suppressed when an element is formed on the transparent substrate. On the other hand, if the thickness of the transparent substrate is too thick, the flexibility and light transmission of the transparent conductor may be reduced.

<< Conductive layer >>
The conductive layer is a layer made of silver or an alloy containing silver as a main component, and contains an element selected from oxygen, sulfur, bromine, chlorine and iodine as a trace element. Here, the alloy containing silver as a main component means an alloy containing 50% by mass or more of silver.

  The trace element contained in the conductive layer may contain the above element alone, may be contained as a silver compound in combination with silver, or may be contained as other compounds. good. Further, the conductive layer may contain two or more elements among oxygen, sulfur, bromine, chlorine and iodine.

  Examples of the silver-based alloy include silver magnesium (AgMg), silver copper (AgCu), silver palladium (AgPd), silver palladium copper (AgPdCu), silver indium (AgIn), silver aluminum (AgAl), Examples include silver molybdenum (AgMo).

  The conductive layer preferably has a layer thickness in the range of 4 to 12 nm. The layer 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 electrode can be maintained. Further, when the layer thickness is 4 nm or more, the conductivity of the layer is also ensured.

  Note that the conductive layer may have a structure in which a plurality of layers are laminated as necessary.

(Content of trace elements)
The content of the trace amount element in the conductive layer is preferably in the range of 1% by mass or less in the conductive layer from the viewpoint of expressing the effect of the present invention, and is 0.001 to 0.5% by mass. More preferably, it is in the range of 0.001 to 0.1% by mass.

(Method for measuring the content of trace elements in the conductive layer)
In the present invention, as a method for obtaining the content of a trace amount element in the conductive layer, after performing ion etching with an ion beam on a transparent electrode or an element including the transparent electrode, and scraping to the conductive layer, X-ray photoelectron spectroscopy (hereinafter referred to as XPS), secondary ion mass spectrometry (hereinafter referred to as SIMS), glow discharge mass spectrometry (GD-MS), glow discharge emission spectrometry (GD-OES) ) And the like. In particular, XPS or SIMS is preferable from the viewpoint of analysis accuracy.

  SIMS is classified into dynamic-SIMS and static-SIMS based on the current density of primary ions used. In the present invention, it is a static mode, in particular, TOF-SIMS (time-of-flight type secondary, which has a high ion transmittance). An ion mass spectrometer) is used. In the measurement, a raw material powder having a known content of any one of the above elements to be observed in advance, such as oxygen and sulfur, is applied or adhered onto a silicon wafer to serve as a reference sample. The reference sample and the element are measured under the same conditions, and the ion signal intensity of the element to be observed obtained from the reference sample measurement is compared with the signal intensity of the element to be observed obtained from the element. Calculate the content of the element you want to observe.

(Method for forming conductive layer)
As a method for forming the conductive layer, a dry process such as a vacuum evaporation method (resistance heating, EB method, etc.), a sputtering method, a CVD method, or the like is used, and the vacuum evaporation method is particularly preferable.

  As a method for forming the conductive layer containing the trace element, for example, in any of the above methods, a state in which the gas of each element as the trace element is introduced into the deposition environment or in the deposition environment There is a method of forming a film after the degree of vacuum is lowered. In addition, for example, after forming a silver layer by any of the above methods, the gas of each element as a trace element is brought into contact with the silver layer, or the degree of vacuum of the film formation environment of the silver layer is lowered (open to the atmosphere). And a method of exposing the silver layer to oxygen or water vapor in the air.

  For example, in the case of forming a conductive layer using a sputtering method, a sputtering target made of silver or an alloy containing silver as a main component is prepared, and the conductive film is formed by performing sputtering film formation using this sputtering target. A layer can be formed.

  In the case of the vapor deposition method, it is possible to adjust the additive concentration of the alloy component with respect to silver by adjusting the vapor deposition rate of silver and the vapor deposition rate of the alloy containing silver as a main component for co-evaporation.

  In addition, the conductive layer is formed on the intermediate layer, so that it is sufficiently conductive even without high-temperature annealing after the film formation, etc. It may be subjected to a high temperature annealing treatment or the like later.

《Middle layer》
The intermediate layer is provided on the transparent substrate as a base of the conductive layer. Such an intermediate layer is a layer containing a substance that interacts with silver, and is disposed adjacent to the conductive layer. Such an intermediate layer may be a layer containing a substance that interacts with silver, and may contain an inorganic material or an organic material.

When the intermediate layer contains an organic material, it preferably contains a Lewis base.
Moreover, when an intermediate | middle layer contains an inorganic material, it is preferable as a substance which interacts with silver to contain the high surface energy material whose sublimation heat enthalpy is larger than silver.

  Further, the intermediate layer may have a structure in which the above-described layer containing an organic material and a layer containing an inorganic material layer are stacked. In this case, the intermediate layer preferably has a configuration in which a layer containing an inorganic material and a layer containing an organic material are arranged in this order from the conductive layer side.

[Intermediate layer containing organic materials]
The intermediate layer may be a layer containing an organic material.
Such an intermediate layer is preferably composed of a compound having a Lewis base, that is, a compound including an atom having an unshared electron pair. Examples of such a compound having a Lewis base include a compound having an element selected from nitrogen and sulfur, that is, a nitrogen-containing compound or a sulfur-containing compound.

  As an example, the intermediate layer is a layer configured using at least one or both of a nitrogen-containing compound and a sulfur-containing compound, and each of the intermediate layers may contain a plurality of types of compounds. Moreover, the compound which comprises an intermediate | middle layer may be a compound containing both nitrogen and sulfur.

  The nitrogen-containing compound constituting the intermediate layer may be a compound containing a nitrogen atom (N), but is particularly preferably an organic compound containing a nitrogen atom having an unshared electron pair. The sulfur-containing compound constituting the intermediate layer may be a compound containing sulfur (S), but is particularly preferably an organic compound containing a sulfur atom having an unshared electron pair.

  Further, even if the intermediate layer is made of a conductive material, it does not become a main electrode. For this reason, the intermediate layer does not need to have a layer thickness required as an electrode, and has a layer thickness appropriately set depending on the arrangement state of the transparent electrode in an electronic device in which the transparent electrode having the intermediate layer is used. If you do.

  Next, the detail of the compound which comprises an intermediate | middle layer is demonstrated in order of the formation method of a nitrogen containing compound (1), a nitrogen containing compound (2), a nitrogen containing compound (3), a sulfur containing compound, and an intermediate | middle layer.

(Nitrogen-containing compound (1))
The nitrogen-containing compound constituting the intermediate layer may be a compound containing a nitrogen atom (N), but is particularly an organic compound containing a nitrogen atom having an unshared electron pair, and may be the following compound: preferable. In other words, the nitrogen-containing compound constituting the intermediate layer has an effective pair of nitrogen atoms that are stably bonded to silver, which is the main material constituting the conductive layer, among the nitrogen atoms contained in the compound. In the case of [unshared electron pair], it is preferable that the content of [effective unshared electron pair] is within a predetermined range.

  Here, the “effective unshared electron pair” is an unshared electron pair that does not participate in aromaticity and is not coordinated to the metal among the unshared electron pairs of the nitrogen atom contained in the compound. I will do it. The aromaticity here refers to an unsaturated cyclic structure in which atoms having π electrons are arranged in a ring, and is aromatic according to the so-called “Hückel's rule”. The condition is that the number is “4n + 2” (n = 0 or a natural number).

  [Effective unshared electron pair] as described above refers to an unshared electron pair possessed by a nitrogen atom regardless of whether or not the nitrogen atom itself provided with the unshared electron pair is a hetero atom constituting an aromatic ring. Is selected depending on whether or not is involved in aromaticity. For example, even if a nitrogen atom is a heteroatom constituting an aromatic ring, an unshared electron pair of the nitrogen atom that does not directly participate as an essential element in aromaticity, that is, a conjugated unsaturated ring structure If an unshared electron pair is not involved in the delocalized π-electron system on the (aromatic ring) as an essential element for the expression of aromaticity, the unshared electron pair is [effective unshared electron pair. ] Is counted. On the other hand, even if a nitrogen atom is not a heteroatom constituting an aromatic ring, if the lone pair of the nitrogen atom is involved in aromaticity, the lone pair of the nitrogen atom Are not counted as [valid unshared electron pairs]. In each compound, the number n of [effective unshared electron pairs] described above coincides with the number of nitrogen atoms having [effective unshared electron pairs].

  Next, the [effective unshared electron pair] described above will be described in detail with a specific example.

  The nitrogen atom is a Group 15 element and has 5 electrons in the outermost shell. Of these, three unpaired electrons are used for covalent bonds with other atoms, and the remaining two become a pair of unshared electron pairs. For this reason, the number of bonds of nitrogen atoms is usually three.

For example, as a group having a nitrogen atom, an amino group (—NR ¹ R ² ), an amide group (—C (═O) NR ¹ R ² ), a nitro group (—NO ₂ ), a cyano group (—CN), diazo Group (—N ₂ ), azide group (—N ₃ ), urea bond (—NR ¹ C═ONR ² —), isothiocyanate group (—N═C═S), thioamide group (—C (═S) NR ¹ R ² ) and the like. R ¹ and R ² are each a hydrogen atom (H) or a substituent. The non-shared electron pair of the nitrogen atom constituting these groups does not participate in aromaticity and is not coordinated to the metal, and thus corresponds to [effective unshared electron pair]. Among these, the unshared electron pair possessed by the nitrogen atom of the nitro group (—NO ₂ ) is used for the resonance structure with the oxygen atom, but has a good effect as shown in the following examples. Therefore, it is considered that it exists on nitrogen as an [effective unshared electron pair] that is not involved in aromaticity and coordinated to a metal.

  A nitrogen atom can also create a fourth bond by using an unshared electron pair.

  For example, tetrabutylammonium chloride (TBAC) is a quaternary ammonium salt in which one of four butyl groups is ionically bonded to a nitrogen atom and has a chloride ion as a counter ion. In this case, one of the electrons constituting the unshared electron pair of the nitrogen atom is donated to the ionic bond with the butyl group. For this reason, the nitrogen atom of TBAC is equivalent to the absence of an unshared electron pair in the first place. Therefore, the unshared electron pair of the nitrogen atom constituting TBAC does not correspond to the [effective unshared electron pair] that is not involved in aromaticity and coordinated to the metal.

For example, tris (2-phenylpyridine) iridium (III) (Ir (ppy) ₃ ) is a neutral metal complex in which an iridium atom and a nitrogen atom are coordinated. The unshared electron pair of the nitrogen atom constituting this Ir (ppy) ₃ is coordinated to the iridium atom, and is utilized for coordination bonding. Therefore, the unshared electron pair of the nitrogen atom constituting Ir (ppy) ₃ does not correspond to the [effective unshared electron pair] that is not involved in aromaticity and coordinated to the metal.

  Moreover, a nitrogen atom is general as a hetero atom which can comprise an aromatic ring, and can contribute to the expression of aromaticity. Examples of the “nitrogen-containing aromatic ring” include pyridine ring, pyrazine ring, pyrimidine ring, triazine ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring, tetrazole ring and the like.

  For example, in a conjugated (resonant) unsaturated ring structure in which a pyridine ring is arranged in a 6-membered ring, the number of delocalized π electrons is 6, so the Hückel rule of 4n + 2 (n = 0 or a natural number) is satisfied. Fulfill. Since the nitrogen atom in the 6-membered ring is substituted with —CH═, only one unpaired electron is mobilized to the 6π-electron system, and the unshared electron pair is essential for the expression of aromaticity. Not involved as a thing.

  Therefore, the unshared electron pair of the nitrogen atom constituting the pyridine ring corresponds to an [effective unshared electron pair] that does not participate in aromaticity and is not coordinated to the metal.

  In addition, for example, a pyrrole ring has a structure in which one of carbon atoms constituting a 5-membered ring is substituted with a nitrogen atom, but the number of π electrons is 6 and the nitrogen-containing material satisfies the Hückel rule. It is an aromatic ring. Since the nitrogen atom of the pyrrole ring is also bonded to a hydrogen atom, an unshared electron pair is mobilized to the 6π electron system.

  Therefore, although the nitrogen atom of the pyrrole ring has an unshared electron pair, since this unshared electron pair is used as an essential element for the expression of aromaticity, it does not participate in aromaticity and is a metal. It does not fall under [Effective unshared electron pairs] that are not coordinated to.

  Further, for example, the imidazole ring is a nitrogen-containing aromatic ring having a structure in which two nitrogen atoms are substituted at positions 1 and 3 in a 5-membered ring, and also has 6 π electrons. One of these nitrogen atoms is a pyridine ring-type nitrogen atom in which only one unpaired electron is mobilized to the 6π-electron system, and the unshared electron pair is not utilized for aromaticity expression. The unshared electron pair of the nitrogen atom corresponds to [effective unshared electron pair]. On the other hand, the other nitrogen atom is a pyrrole-ring-type nitrogen atom that mobilizes the unshared electron pair to the 6π electron system, and therefore, the unshared electron pair of the other nitrogen atom is [effective unshared electron. It does not correspond to [pair].

  Accordingly, in the imidazole ring, only the unshared electron pair of one of the two nitrogen atoms constituting the ring corresponds to [effective unshared electron pair].

  The selection of the unshared electron pair at the nitrogen atom of the “nitrogen-containing aromatic ring” as described above is similarly applied to a condensed ring compound having a nitrogen-containing aromatic ring skeleton.

  For example, the δ-carboline ring is a condensed ring compound having a nitrogen-containing aromatic ring skeleton, and is an azacarbazole compound in which a benzene ring skeleton, a pyrrole ring skeleton, and a pyridine ring skeleton are condensed in this order. Of these, the nitrogen atom of the pyridine ring mobilizes only one unpaired electron to the π-electron system, and the nitrogen atom of the pyrrole ring mobilizes an unshared electron pair to the π-electron system, forming a ring. Together with 11 π electrons from carbon atoms, the total number of π electrons is 14 aromatic rings.

  Therefore, among the two nitrogen atoms of the δ-carboline ring, the unshared electron pair of the nitrogen atom constituting the pyridine ring corresponds to [effective unshared electron pair], but the unshared electron of the nitrogen atom constituting the pyrrole ring. The pair does not fall under [Effective unshared electron pair].

  In this way, the unshared electron pair of the nitrogen atom constituting the condensed ring compound is involved in the bond in the condensed ring compound as well as the bond in the monocyclic compound such as pyridine ring and pyrrole ring constituting the condensed ring compound. To do.

  The [effective unshared electron pair] described above is important for exhibiting a strong interaction with silver which is the main component of the conductive layer. The nitrogen atom having such an [effective unshared electron pair] is preferably a nitrogen atom in the nitrogen-containing aromatic ring from the viewpoint of stability and durability. Therefore, the compound contained in the intermediate layer preferably has an aromatic heterocycle having a nitrogen atom having [effective unshared electron pair] as a heteroatom.

In particular, in this embodiment, the number n of [effective unshared electron pairs] with respect to the molecular weight M of such a compound is defined as, for example, the effective unshared electron pair content [n / M]. And it is preferable that the intermediate | middle layer is comprised using the compound selected so that this [n / M] may be 2.0 * 10 < ^-3 ><= [n / M]. Further, the intermediate layer is more preferable if the effective unshared electron pair content [n / M] defined as described above is in the range of 3.9 × 10 ⁻³ ≦ [n / M]. More preferably, the range is 5 × 10 ⁻³ ≦ [n / M].

  The intermediate layer is preferably composed of a nitrogen-containing compound whose effective unshared electron pair content [n / M] is within the predetermined range described above, and even if it is composed of only such a compound. Alternatively, such a compound and another compound may be mixed and used. The other compound may or may not contain a nitrogen atom, and the effective unshared electron pair content [n / M] may not be within the predetermined range described above.

  When the intermediate layer is composed of a plurality of compounds, for example, based on the mixing ratio of the compounds, the molecular weight M of the mixed compound obtained by mixing these compounds is obtained, and [effective non-shared electrons for this molecular weight M are determined. The total number n of pairs is determined as an average value of the effective unshared electron pair content [n / M], and this value is preferably within the predetermined range described above. That is, the effective unshared electron pair content [n / M] of the intermediate layer itself is preferably within a predetermined range.

  In addition, when the intermediate layer is configured using a plurality of compounds and the mixing ratio (content ratio) of the compounds is different in the layer thickness direction, the intermediate layer on the side in contact with the conductive layer The effective unshared electron pair content [n / M] in the surface layer may be in a predetermined range.

The intermediate layer is formed using a compound having the above-mentioned effective unshared electron pair content [n / M] of 2.0 × 10 ⁻³ ≦ [n / M] as a compound constituting the nitrogen-containing compound. Thus, it is possible to provide an intermediate layer that can reliably obtain the effect of “suppressing aggregation of silver” of the conductive layer. This is confirmed from the fact that a conductive layer capable of measuring sheet resistance is formed on such an intermediate layer, although it is an extremely thin film of 9 nm, for example.

Specific examples of nitrogen-containing compounds satisfying the above-described effective unshared electron pair content [n / M] of 2.0 × 10 ⁻³ ≦ [n / M] as nitrogen-containing compounds constituting the intermediate layer ( No. 1 to No. 48). Each nitrogen-containing compound No. 1-No. 48 is marked with a circle with respect to a nitrogen atom having [effective unshared electron pair]. Table 1 below shows these nitrogen-containing compound Nos. 1-No. The molecular weight M of 48, the number n of [effective unshared electron pairs], and the effective unshared electron pair content [n / M] are shown. The following nitrogen-containing compound no. In 33 copper phthalocyanines, unshared electron pairs that are not coordinated to copper among the unshared electron pairs of the nitrogen atom are counted as [effective unshared electron pairs].

  Table 1 shows the corresponding general formulas when these exemplified nitrogen-containing compounds also belong to the general formulas (1) to (8a) representing other nitrogen-containing compounds (2) described below. It was.

(Nitrogen-containing compound (2))
Further, the nitrogen-containing compound constituting the intermediate layer is not limited to the nitrogen-containing compound (1) in which the effective unshared electron pair content [n / M] is within the predetermined range described above, and other nitrogen A contained compound may be used. As the other nitrogen-containing compound used in the intermediate layer, a compound containing a nitrogen atom is preferably used regardless of whether the effective unshared electron pair content [n / M] is within the predetermined range described above. Among them, the compound containing a nitrogen atom having the [effective unshared electron pair] described above is particularly preferably used. Further, as the other nitrogen-containing compound used in the intermediate layer, a compound having properties required for each electronic device to which the transparent electrode provided with the intermediate layer is applied is used. For example, when this transparent electrode is used as an electrode of an organic EL element, from the viewpoint of film formability, the nitrogen-containing compound constituting the intermediate layer is represented by the following general formulas (1) to (8a). A nitrogen-containing compound (2) having the structure represented is used.

  Among the nitrogen-containing compounds (2) having a structure represented by these general formulas (1) to (8a), nitrogen-containing compounds that fall within the range of the effective unshared electron pair content [n / M] described above Such a nitrogen-containing compound can be used alone as a nitrogen-containing compound constituting the intermediate layer (see Table 1 above). On the other hand, if the compound having the structure represented by the following general formulas (1) to (8a) is a nitrogen-containing compound that does not fall within the range of the effective unshared electron pair content [n / M] described above, It is preferably used as a compound constituting the intermediate layer by mixing with a nitrogen-containing compound having a shared electron pair content [n / M] in the range described above.

  X11 in the general formula (1) represents -N (R11)-or -O-. In addition, E101 to E108 in the general formula (1) each represent -C (R12) = or -N =. At least one of E101 to E108 is -N =. R11 and R12 each represent a hydrogen atom (H) or a substituent.

  Examples of this substituent include alkyl groups (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group). Etc.), cycloalkyl groups (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl groups (for example, vinyl group, allyl group, etc.), alkynyl groups (for example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon groups (aromatic Also called group carbocyclic group, aryl group, etc., for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl 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 Any carbon atom constituting the carboline ring is replaced with a nitrogen atom.), Phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (For example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (For example, Enoxy 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 groups (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl groups (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryl Oxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfo group) Nyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl 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 group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, Carbonyl group, etc.), amide groups (eg, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octyl) Carbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, Cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylamino Sulfonyl 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 (eg, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (eg, amino group, ethylamino group) Dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, piperidyl group (also referred to as piperidinyl group), 2,2,6, 6-tetramethylpiperidinyl group etc.), halogen atoms (eg fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon groups (eg fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, penta Fluorophenyl group), cyano group Nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphate ester group (for example, dihexyl phosphoryl group, etc.), phosphorous acid An ester group (for example, diphenylphosphinyl group etc.), a phosphono group etc. are mentioned.

  Some of these substituents may be further substituted with the above substituents. A plurality of these substituents may be bonded to each other to form a ring. As these substituents, those which do not inhibit the interaction between the compound and silver (Ag) are preferably used, and those having a nitrogen atom having an effective unshared electron pair described above are particularly preferably applied. . In addition, the description regarding the above substituent applies similarly to the substituent shown in description of general formula (2)-(8a) demonstrated below.

  The nitrogen-containing compound having the structure represented by the general formula (1) as described above is preferable because a strong interaction can be expressed between the nitrogen atom in the compound and silver constituting the conductive layer.

  The compound having the structure represented by the general formula (1a) is one form of the compound having the structure represented by the general formula (1), and X11 in the general formula (1) is represented by —N (R11) —. It is the compound which was made. Such a nitrogen-containing compound is preferable because the interaction can be expressed more strongly.

  The compound having the structure represented by the general formula (1a-1) is one form of the compound having the structure represented by the general formula (1a), and E104 in the general formula (1a) is set to -N =. A compound. Such a nitrogen-containing compound is preferable because the above interaction can be expressed more effectively.

  The compound having the structure represented by the general formula (1a-2) is another embodiment of the compound having the structure represented by the general formula (1a), and E103 and E106 in the general formula (1a) are represented by -N = is a compound. Such a nitrogen-containing compound is preferable because it has a larger number of nitrogen atoms and can express the above interaction more strongly.

  The compound having the structure represented by the general formula (1b) is another embodiment of the compound having the structure represented by the general formula (1), and X11 in the general formula (1) is -O-. , E104 is a compound in which -N =. Such a compound is preferable because the above interaction can be expressed more effectively.

  Furthermore, a compound having a structure represented by the following general formulas (2) to (8a) is preferable because the interaction can be expressed more effectively.

  The general formula (2) is also an embodiment of the general formula (1). In the general formula (2), Y21 represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof. E201 to E216 and E221 to E238 each represent -C (R21) = or -N =. R21 represents a hydrogen atom (H) or a substituent. However, at least one of E221 to E229 and at least one of E230 to E238 represents -N =. k21 and k22 represent an integer of 0 to 4, but k21 + k22 is an integer of 2 or more.

  In the general formula (2), examples of the arylene group represented by Y21 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 (2), examples of the heteroarylene group represented by Y21 include a carbazole ring, a carboline ring, a diazacarbazole ring (also referred to as a monoazacarboline ring, and one of carbon atoms constituting the carboline ring). A ring structure with a nitrogen atom replaced.), Triazole ring, pyrrole ring, pyridine ring, pyrazine ring, quinoxaline ring, thiophene ring, oxadiazole ring, dibenzofuran ring, dibenzothiophene ring, indole ring Examples are derived divalent groups and the like.

  As a preferred embodiment of the divalent linking group consisting of an arylene group, heteroarylene group or a combination thereof represented by Y21, 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 (2), when R21 of —C (R21) ═ represented by E201 to E216 and E221 to E238 is a substituent, examples of the substituent include R11 of the general formula (1), The substituents exemplified as R12 apply similarly.

  In General formula (2), it is preferable that 6 or more of E201-E208 and 6 or more of E209-E216 are each represented by -C (R21) =.

  In the general formula (2), it is preferable that at least one of E225 to E229 and at least one of E234 to E238 represent -N =.

  Furthermore, in General formula (2), it is preferable that any one of E225-E229 and any one of E234-E238 represent -N =.

  Moreover, in General formula (2), it is mentioned as a preferable aspect that E221-E224 and E230-E233 are each represented by -C (R21) =.

  Further, in the compound having the structure represented by the general formula (2), it is preferable that E203 is represented by -C (R21) = and R21 represents a linking site, and E211 is also represented by -C (R21 ) = And R21 preferably represents a linking site.

  Further, E225 and E234 are preferably represented by -N =, and E221 to E224 and E230 to E233 are each preferably represented by -C (R21) =.

  The general formula (3) is also an embodiment of the general formula (1a-2). In the general formula (3), E301 to E312 each represent -C (R31) =, and R31 represents a hydrogen atom (H) or a substituent. Y31 represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof.

  In the general formula (3), when R31 of —C (R31) ═ represented by E301 to E312 is a substituent, examples of the substituent include R11 and R12 of the general formula (1). The same substituents apply as well.

  Moreover, in General formula (3), as a preferable aspect of the bivalent coupling group which consists of an arylene group represented by Y31, heteroarylene group, or those combinations, the thing similar to Y21 of General formula (2) is mentioned. It is done.

  The general formula (4) is also an embodiment of the general formula (1a-1). In the general formula (4), E401 to E414 each represent -C (R41) =, and R41 represents a hydrogen atom (H) or a substituent. Ar41 represents a substituted or unsubstituted aromatic hydrocarbon ring or aromatic heterocyclic ring. Furthermore, k41 represents an integer of 3 or more.

  In the general formula (4), when R41 of —C (R41) ═ represented by E401 to E414 is a substituent, examples of the substituent are exemplified as R11 and R12 in the general formula (1). The same substituents apply as well.

  In the general formula (4), when Ar41 represents an aromatic hydrocarbon ring, examples of the aromatic hydrocarbon ring include a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an anthracene ring, a phenanthrene ring, and 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. These rings may further have the substituents exemplified as R11 and R12 in the general formula (1).

  In the general formula (4), when Ar41 represents an aromatic heterocycle, examples of the aromatic heterocycle include a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, Pyrazine ring, 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 ring and the like. The azacarbazole ring refers to one in which at least one carbon atom of the benzene ring constituting the carbazole ring is replaced with a nitrogen atom. These rings may further have the substituents exemplified as R11 and R12 in the general formula (1).

  In the general formula (5), R51 represents a substituent. E501, E502, E511 to E515, and E521 to E525 each represent -C (R52) = or -N =. E503 to E505 each represent -C (R52) =. R52 represents a hydrogen atom (H) or a substituent. At least one of E501 and E502 is -N =, at least one of E511-E515 is -N =, and at least one of E521-E525 is -N =.

  In the general formula (5), when R51 represents a substituent and R52 represents a substituent, examples of these substituents are the same as those exemplified as R11 and R12 in the general formula (1). The

  In the general formula (6), E601 to E612 each represent —C (R61) ═ or —N═, and R61 represents a hydrogen atom (H) or a substituent. Ar61 represents a substituted or unsubstituted aromatic hydrocarbon ring or aromatic heterocyclic ring.

  In the general formula (6), when R61 of —C (R61) ═ represented by E601 to E612 is a substituent, examples of the substituent include R11 and R12 of the general formula (1). The same substituents apply as well.

  In the general formula (6), the substituted or unsubstituted aromatic hydrocarbon ring or aromatic heterocyclic ring represented by Ar61 includes the same as Ar41 in the general formula (4).

  In the general formula (7), R71 to R73 each represents a hydrogen atom (H) or a substituent, and Ar71 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group.

  In addition, in the general formula (7), examples of the aromatic hydrocarbon ring or aromatic heterocycle represented by Ar71 include those similar to Ar41 in the general formula (4).

  The general formula (8) is also a form of the general formula (7). In the general formula (8), R81 to R86 each represent a hydrogen atom (H) or a substituent. E801 to E803 each represent -C (R87) = or -N =, and R87 represents a hydrogen atom (H) or a substituent. Ar81 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group.

  In the general formula (8), the aromatic hydrocarbon ring or aromatic heterocyclic ring represented by Ar81 may be the same as Ar41 in the general formula (4).

  The nitrogen-containing compound having the structure represented by the general formula (8a) is one form of the nitrogen-containing compound having the structure represented by the general formula (8), and Ar81 in the general formula (8) is a carbazole derivative. . In the general formula (8a), E804 to E811 each represent —C (R88) ═ or —N═, and R88 represents a hydrogen atom (H) or a substituent. At least one of E808 to E811 is -N =, and E804 to E807 and E808 to E811 may be bonded to each other to form a new ring.

(Nitrogen-containing compound (3))
In addition to the compounds represented by the general formulas (1) to (8a) and other general formulas as other nitrogen-containing compounds (3) constituting the intermediate layer, specific examples are shown below. Compounds 1-166 are exemplified. These compounds are materials having an electron transport property or an electron injection property. In addition, in these compounds 1-166, the compound applicable to the range of the above-mentioned effective unshared electron pair content [n / M] is also included, and you may use as a compound which comprises an intermediate | middle layer independently. Further, among these compounds 1 to 166, there are compounds that fall under the general formulas (1) to (8a) described above and other general formulas.

(Sulfur-containing compounds)
The sulfur-containing compound contained in the intermediate layer may be a compound containing sulfur (S), but is particularly preferably an organic compound containing a sulfur atom having an unshared electron pair, and a divalent sulfur atom. The following general formula (9), general formula (10), general formula (11) or general formula (12) is more preferable.

In the general formula (9), R ₉₁ and R ₉₂ represent a substituent. As the substituents represented by R ₉₁ and R ₉₂ , the substituents exemplified as R11 and R12 in the general formula (1) are similarly applied.

In the general formula (10), R ₉₃ and R ₉₄ represent a substituent. As the substituents represented by R ₉₃ and R ₉₄ , the substituents exemplified as R11 and R12 in the general formula (1) are similarly applied.

In the above general formula (11), R ₉₅ represents a substituent. Examples of the substituent represented by R _95, exemplified substituents R11, as R12 of the general formula (1) is applied in the same manner.

In the above general formula (12), R ₉₆ represents a substituent. Examples of the substituent represented by R _96, exemplified substituents R11, as R12 of the general formula (1) is applied in the same manner.

  Specific examples of the sulfur-containing compound contained in the intermediate layer are shown below, but the sulfur-containing compound is not limited to these exemplified compounds.

  The following compound is mentioned as a specific example of the compound represented by General formula (9) which has a bivalent sulfur atom among the organic compounds (sulfur-containing compound) containing the sulfur atom which has an unshared electron pair.

  Moreover, the following compound is mentioned as a specific example of a compound represented by General formula (10).

  Moreover, the following compound is mentioned as a specific example of a compound represented by General formula (11).

  Moreover, the following compound is mentioned as a specific example of a compound represented by General formula (12).

In addition to the compounds exemplified above, the sulfur-containing compound constituting the intermediate layer has an effective unshared electron pair content [n / M] of 2.0 × 10 ⁻³ ≦ [ n / M] may be used, and a range of 3.9 × 10 ⁻³ ≦ [n / M] is more preferable.

  Here, the effective unshared electron pair content [n / M] is the same as defined in the nitrogen-containing compound (1). That is, among the sulfur atoms contained in the sulfur-containing compound, in particular, when the unshared electron pair of the sulfur atom that stably binds to silver, which is the main material constituting the conductive layer, is [effective unshared electron pair] The number of [effective unshared electron pairs] with respect to the molecular weight M of the compound is n.

(Method for forming intermediate layer)
As the method for forming the intermediate layer as described above, for example, a method using a wet process such as a coating method, an inkjet method, a coating method, a dip method, a vapor deposition method (resistance heating method, EB method, etc.), sputtering method, CVD, etc. And a method using a dry process such as a method. Of these, the vapor deposition method is preferably applied.

  In particular, in the case of forming an intermediate layer using a plurality of compounds, co-evaporation in which a plurality of compounds are simultaneously supplied from a plurality of evaporation sources is applied. Moreover, if a polymer material is used as the compound, a coating method is preferably applied. In this case, a coating solution in which the compound is dissolved in a solvent is used. The solvent in which the compound is dissolved is not limited. Furthermore, if the intermediate layer is formed using a plurality of compounds, the coating solution may be prepared using a solvent capable of dissolving the plurality of compounds.

[Intermediate layer containing inorganic material]
The intermediate layer may be a layer containing an inorganic material.
When the intermediate layer contains an inorganic material, the intermediate layer is a layer made of a high surface energy material having a higher sublimation heat enthalpy than silver (Ag) constituting the conductive layer, and the conductive layer includes Provided in contact. Materials having a higher sublimation heat enthalpy than silver (Ag) (high surface energy materials) include aluminum (Al), titanium (Ti), gold (Au), platinum (Pt), palladium (Pd), indium (In ), Mo (molybdenum), copper (Cu), and the like.

  In the case where the intermediate layer contains an inorganic material, the intermediate layer may be configured using at least one of the above materials, and may contain these materials as a main component and other materials. As other materials, silver (Ag), magnesium (Mg), copper (Cu), indium (In), lithium (Li), or the like is used.

These materials may be contained in the intermediate layer in an oxide state. For example, molybdenum (Mo) may be contained as molybdenum oxide (MoO ₂ , MoO ₃ ).

  The intermediate layer containing the inorganic material as described above is preferably formed with a layer thickness having optical transparency. Such an intermediate layer does not need to be configured as a continuous film, and may have an island shape or a shape having a plurality of holes. In particular, when the intermediate layer contains a metal material, this intermediate layer constitutes a transparent electrode of the organic EL element together with the adjacent conductive layer. Even in this case, it is important that the intermediate layer has a layer thickness that is extremely thin enough to have optical transparency.

<< Structure of organic electroluminescence element >>
FIG. 2 is a cross-sectional configuration diagram showing a configuration example of the organic EL element using the transparent electrode described above. Hereinafter, the configuration of the organic EL element will be described with reference to this figure. Here, a configuration in which the transparent electrode 10 is applied as a transparent electrode will be described.

  The organic EL element 100 shown in FIG. 2 is configured by laminating a light emitting functional layer 3 and a counter electrode 5 in this order on a transparent electrode 10. For this reason, the organic EL element 100 is configured as a bottom emission type in which the emitted light h is extracted from at least the transparent substrate 11 side.

  Further, the overall layer structure of the organic EL element 100 is not limited and may be a general layer structure. Here, the transparent electrode 10 is disposed on the anode (that is, anode) side, and the conductive layer 1b mainly functions as an anode, while the counter electrode 5 functions as a cathode (that is, cathode).

  In this case, for example, the light emitting functional layer 3 is formed by stacking [hole injection layer 3a / hole transport layer 3b / light emitting layer 3c / electron transport layer 3d / electron injection layer 3e] in this order from the transparent electrode 10 side serving as an anode. Although the configuration is exemplified, it is essential to have the light emitting layer 3c configured using at least an organic material. The hole injection layer 3a and the hole transport layer 3b may be provided as a hole transport / injection layer having a hole transport property and a hole injection property. The electron transport layer 3d and the electron injection layer 3e may be provided as a single layer having electron transport properties and electron injection properties. Of these light emitting functional layers 3, for example, the electron injection layer 3e may be composed of an inorganic material.

  If the conductive layer 1b in the transparent electrode 10 is a cathode and the counter electrode 5 is an anode, the stacking order of the light emitting functional layers 3 from the transparent electrode 10 side may be reversed.

  Further, in addition to these layers, the light emitting functional layer 3 may be laminated with a hole blocking layer, an electron blocking layer, or the like as necessary. Further, the light emitting layer 3c has each color light emitting layer for generating light emission in each wavelength region, and each color light emitting layer may be laminated through a non-light emitting layer to form a light emitting layer unit. good. The non-light emitting layer may function as a hole blocking layer or an electron blocking layer. Furthermore, the counter electrode 5 as a cathode may also have a laminated structure as required. In such a configuration, only a portion where the light emitting functional layer 3 is sandwiched between the transparent electrode 10 and the counter electrode 5 is a light emitting region in the organic EL element 100.

  The organic EL element 100 having the above configuration is provided with a sealing material 17 to be described later on the transparent substrate 11 for the purpose of preventing deterioration of the light emitting functional layer 3 configured using an organic material or the like. Yes. The sealing material 17 is fixed to the transparent substrate 11 side with an adhesive 19. However, it is assumed that the terminal portions of the transparent electrode 10 and the counter electrode 5 are provided on the transparent substrate 11 so as to be exposed from the sealing material 17 while being insulated from each other by the light emitting functional layer 3.

  Hereinafter, the detail of each main layer for comprising the organic EL element 100 mentioned above is demonstrated.

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

  This light-emitting layer is a layer that emits light by recombination of electrons injected from the cathode side and holes injected from the anode side. Even if the light-emitting portion is within the layer of the light-emitting layer, It may be an interface with an adjacent layer.

  Such a light emitting layer is not particularly limited in its configuration as long as the contained light emitting material satisfies the light emission requirements. 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 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 sum of the thicknesses of the light emitting layers is a layer thickness including a non-light emitting layer between the light emitting layers.

  In the case of a light emitting layer having a structure 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. When the plurality of stacked light emitting layers correspond to the respective emission colors of blue, green, and red, there is no particular limitation on the relationship between the thicknesses of the blue, green, and red light emitting layers.

  The light emitting layer 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.

  The light-emitting layer may be a mixture of a plurality of light-emitting materials, or 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. .

  The light-emitting layer preferably includes a host compound (also referred to as a light-emitting host) and a light-emitting material (also referred to as a light-emitting dopant compound or a guest material) and emits light from the light-emitting material.

(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 organic EL element can be made highly efficient. In addition, by using a plurality of kinds of light emitting materials described later, it is possible to mix different light emission, thereby obtaining an arbitrary light emission color.

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

  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).

  Specific examples of the host compound applicable to the organic EL element include compounds H1 to H79 described in paragraphs 0163 to 0178 of JP2013-4245A.

  In addition, as specific examples of other 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, it is a compound that emits phosphorescence at room temperature (25 ° C.), and the phosphorescence quantum yield is 0 at 25 ° C. A preferred phosphorescence quantum yield is 0.1 or more, although it is defined as 0.01 or more compounds.

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

  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 emit light from the phosphorescent compound. Energy transfer type. The other is a carrier trap type in which the phosphorescent compound becomes a carrier trap, and recombination of carriers occurs on the phosphorescent compound, and light emission from the phosphorescent compound is obtained. In either case, the condition is that the excited state energy of the phosphorescent compound is lower than the excited state energy of the host compound.

  The phosphorescent compound can be appropriately selected from known compounds used for the light emitting layer of a general organic EL device, but preferably contains a group 8-10 metal in the periodic table of elements. More preferred are iridium compounds, more preferably 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 varies in the thickness direction of the light emitting layer. May be.

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

  Examples of phosphorescent compounds applicable to the present invention include those represented by general formula (4), general formula (5) or general formula (6) described in paragraphs 0185 to 0244 of JP2013-4245A. Preferred examples of the compound and the exemplified compounds thereof are given below. As other exemplary compounds, for example, Ir-46 to Ir-50 are shown below.

  These phosphorescent compounds (also referred to as phosphorescent metal complexes) are preferably contained in the light emitting layer as a light emitting dopant, but are contained in each functional layer other than the light emitting layer. May be.

  In addition, the phosphorescent compound can be appropriately selected from known compounds used for the light emitting layer.

  The phosphorescent compound (also referred to as a phosphorescent metal complex or the like) is described in, for example, Organic Letters, 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. 26, 1171 (2002), European Journal of Organic Chemistry, Vol. 4, pages 695-709 (2004), and further synthesized 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 exist between the anode and the light emitting layer or the hole transport layer, and if it is an electron injection layer, it may exist 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 according to the present invention is desirably an extremely thin film, and the layer thickness is preferably in the range of 1 nm to 10 μm although it depends on the material.

《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, and also two fused aromatic rings described in US Pat. No. 5,061,569. In the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308688 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (MTDATA) in which three triphenylamine units described in the publication are linked in a starburst type Etc.

  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 layer thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The 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 multi-layer structure.

  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. It suffices if it has a function of transmitting to. 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.

In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq ₃ ), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) Aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., 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. In addition, distyrylpyrazine derivatives exemplified as the material of the light emitting layer can also be used as the material of the electron transport layer, and inorganic materials such as n-type Si and n-type SiC can be used as well as the hole injection layer and the hole transport layer. A semiconductor 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 layer 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.

Examples of the material (electron transporting compound) of the electron transporting layer include the above-mentioned compound No. 1-No. It is preferable to use 48 nitrogen-containing compounds, nitrogen-containing compounds represented by the above general formulas (1) to (8a), and nitrogen-containing compounds 1 to 166 described above.
Moreover, the sulfur containing compound represented by General formula (9)-General formula (12), the above-mentioned 1-1 to 1-9, 2-1 to 2-11, 3-1 to 3-23, and 4 It is preferable to use a sulfur-containing compound of -1.

<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 transport layer described above can be used as a hole blocking layer according to the present invention, if necessary. 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 above can be used as an electron blocking layer as needed. The layer thickness of the blocking layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

《Counter electrode (cathode)》
The counter electrode is disposed as an upper electrode on the light emitting functional layer. This counter electrode is an electrode film that functions as a cathode for supplying electrons to the light emitting functional layer, and 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 counter electrode as described above can be produced by forming a thin film of these conductive materials by a method such as vapor deposition or sputtering. It is preferred to be membraned. The sheet resistance as the counter electrode is several hundred Ω / sq. The following is preferable, and the thickness is usually selected in the range of 5 nm to 5 μm, preferably 5 to 200 nm.

  If the organic EL element is a double-sided light emitting type that also takes out the emitted light h from the counter electrode side, a counter electrode is configured by selecting a conductive material having good light transmittance from the above-described conductive materials. Just do it.

<< Sealant >>
The sealing material covers the transparent electrode, the light emitting functional layer, the counter electrode, and the like, and may or may not have optical transparency. Such a sealing material may be a plate-like (film-like) sealing member that is fixed to the transparent substrate side by an adhesive, or may be a sealing film.

  Examples of the plate-like (film-like) sealing material include, but are not limited to, a glass substrate and a polymer substrate. Further, these substrate materials may be used in the form of a thinner film.

  Examples of the glass substrate include soda lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer substrate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone.

  Among them, since the element can be thinned, a thin film-like polymer substrate can be preferably used as the sealing material.

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

  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, what was comprised with the metal material as another example of a plate-shaped sealing material can be used. Examples of the metal material 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. . By using such a metal material as a sealing material in the form of a thin film, the entire light-emitting panel provided with the organic EL element can be thinned.

  Further, the adhesive for fixing the plate-shaped sealing material as described above to the transparent substrate side is a sealing agent for sealing the light emitting functional layer or the like sandwiched between the sealing material and the transparent substrate. Used as 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.

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

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

  Application | coating of the adhesive agent to the adhesion part of a sealing material and a transparent substrate may use commercially available dispenser, and may print like screen printing. As shown in the figure, this adhesive may be provided only on the periphery of the sealing material, or if it is a material having sufficient light transmittance after curing, it is filled without any gap between the sealing material and the transparent substrate. May be.

  In addition, when a gap is formed between the plate-shaped sealing material, the transparent substrate, and the adhesive, the gap includes an inert gas such as nitrogen or argon or a fluorinated hydrocarbon in the gas phase and the liquid phase. Preferably, an inert liquid such as silicon oil is injected. A vacuum can also be used. Moreover, a hygroscopic compound can also be enclosed inside.

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

  On the other hand, when a sealing film is used as a sealing material, the light emitting functional layer in the organic EL element is completely covered, and the transparent electrode and the counter electrode terminal part in the organic EL element are exposed and sealed on the transparent substrate. A membrane is provided.

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

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

  The sealing material as described above is provided in a state in which the terminal portions of the transparent electrode and the counter electrode in the organic EL element are exposed and at least the light emitting functional layer is covered. Further, an electrode may be provided on the sealing material so that the transparent electrode of the organic EL element and the terminal portion of the counter electrode are electrically connected to this electrode.

  In the case where the organic EL element is one that takes out the emitted light h from the counter electrode side, the sealing material is a transparent sealing having light transmittance from the above-described plate-shaped sealing member or sealing film. A material is used, and the surface of the sealing material also serves as a light extraction surface from which the emitted light h of the organic EL element is extracted.

《Auxiliary electrode》
Furthermore, although illustration is omitted here, in the above configuration, an auxiliary electrode may be provided in contact with the conductive layer of the transparent electrode for the purpose of reducing the resistance of the transparent electrode. . The auxiliary electrode is provided for the purpose of reducing the resistance of the transparent electrode, and is provided in contact with the conductive layer 1b of the transparent electrode. The material for forming the auxiliary electrode is preferably a metal with low resistance, such as gold, platinum, silver, copper, and 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, for example, 50 μm or less from the viewpoint of the aperture ratio for extracting light, and the thickness of the auxiliary electrode is preferably, for example, 1 μm or more from the viewpoint of conductivity.

<< Method for Manufacturing Organic EL Element >>
The manufacture of the organic EL element 100 as described above is performed as follows.

  First, the intermediate layer 1 a and the conductive layer 1 b are formed on one main surface of the transparent substrate 11. Here, the method described above can be used as a method of forming the intermediate layer 1a and the conductive layer 1b.

  In addition, after forming the intermediate | middle layer 1a and the electroconductive layer 1b, you may pattern each formed layer in a predetermined shape. Further, before and after the formation of the conductive layer 1b, an auxiliary electrode pattern may be formed as necessary.

Next, a hole injection layer 3 a, a hole transport layer 3 b, a light emitting layer 3 c, an electron transport layer 3 d, and an electron injection layer 3 e are formed in this order to form the light emitting functional layer 3. These layers can be formed by, for example, a spin coating method, a casting method, an ink jet method, a vapor deposition method, a sputtering method, a printing method, or the like. Among these, the vacuum deposition method or the spin coating method is particularly preferable from the viewpoints that a homogeneous film is easily obtained and pinholes are hardly generated. Further, different formation methods may be applied for each layer. When employing a vapor deposition method for forming each of these layers, the vapor deposition conditions vary depending on the type of compound used, etc., but generally the boat heating temperature storing the compound is 50 to 450 ° C., the degree of vacuum is 10 ⁻⁶ to 10 ⁻² Pa, It is desirable to appropriately select each condition in the range of a deposition rate of 0.01 to 50 nm / second, a substrate temperature of −50 to 300 ° C., and a layer thickness of 0.1 to 5 μm.

  Next, the counter electrode 5 serving as a cathode is formed by an appropriate forming method such as vapor deposition or sputtering.

  In the formation of each layer as described above, film formation using, for example, a mask is performed as necessary, or after each layer is formed, each formed layer is patterned into a predetermined shape. Thereby, while maintaining the insulation state between the transparent electrode 10 and the counter electrode 5 by the light emitting functional layer 3, each layer is patterned in a shape in which the terminal portions of the transparent electrode 10 and the counter electrode 5 are drawn out on the periphery of the transparent substrate 11. Can do.

  Thereafter, a sealing material 17 that covers at least the light emitting functional layer 3 is provided in a state where the terminal portions of the transparent electrode 10 and the counter electrode 5 in the organic EL element 100 are exposed. At this time, the sealing material 17 is bonded to the transparent substrate 11 side using the adhesive 19, and the light emitting functional layer 3 and the like are sealed between the sealing material 17 and the transparent substrate 11.

  As described above, the bottom emission type organic EL element 100 that extracts the emitted light h from the transparent substrate 11 side (light extraction surface 13a) provided with the transparent electrode 10 is obtained. In the production of such an organic EL element 100, it is preferable to produce from the light emitting functional layer 3 to the counter electrode 5 consistently by a single evacuation. However, the transparent substrate 11 is taken out from the vacuum atmosphere in the middle and differently formed. A film method may be applied. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  When a DC voltage is applied to the organic EL element 100 thus obtained, the transparent electrode 10 (conductive layer 1b) as an anode has a positive polarity and the counter electrode 5 as a cathode has a negative polarity. When a voltage of about 2 to 40 V is applied, light emission can be observed. Moreover, you may apply an alternating voltage. The alternating current waveform to be applied may be arbitrary.

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

<< Production of Organic EL Element 1 >>
(Formation of transparent electrode)
First, a non-alkali glass transparent substrate was prepared and fixed to a substrate holder of a commercially available vacuum deposition apparatus. In addition, a resistance heating boat made of molybdenum or tungsten was filled with a constituent material of each layer constituting the organic EL element by an amount optimal for layer formation. These substrate holders and resistance heating boats were attached to the first vacuum chamber of the vacuum deposition apparatus. Moreover, silver was put into the resistance heating boat made from molybdenum or tungsten, and it attached to the 2nd vacuum chamber.

Next, the first vacuum chamber and the second vacuum chamber were depressurized to 4.0 × 10 ⁻⁴ Pa, and then heated by energizing a resistance heating boat containing the compound 14 exemplified as the nitrogen-containing compound (3). 14 was deposited on the transparent substrate at a deposition rate of 0.1 to 0.2 nm / second to form an intermediate layer having a layer thickness of 25 nm.

Next, a conductive layer was formed by a vacuum vapor deposition method using resistance heating. Specifically, the transparent substrate on which the intermediate layer is formed is transferred to the second vacuum chamber while being kept in a vacuum state, and then heated by energizing a resistance heating boat containing silver, so that the deposition rate of silver is 0.1. Vapor deposition was performed on the intermediate layer at ˜0.2 nm / second to form a conductive layer having a layer thickness of 10 nm. Moreover, when vapor-depositing silver, the mask was used and the electroconductive layer was formed in pattern shape.
In this way, a transparent electrode composed of the intermediate layer and the conductive layer was formed.

(Formation of hole injection transport layer)
Next, the transparent substrate on which the conductive layer is formed is transferred to the first vacuum tank while being kept in a vacuum state, and then heated by energizing a resistance heating boat containing the compound M-2. It vapor-deposited on the transparent electrode with the vapor deposition rate of 0.1 nm / sec, and formed the positive hole injection transport layer with a layer thickness of 40 nm.

(Formation of fluorescent light emitting layer)
Next, the resistance heating boat containing compound BD-1 and compound H-1 is energized and heated, and the content of compound BD-1 in the formed layer is 5% by volume, and the content of compound H-1 Was vapor-deposited on the hole injecting and transporting layer at a deposition rate of 0.1 nm / second to form a fluorescent light emitting layer exhibiting blue light emission with a layer thickness of 15 nm.

(Formation of phosphorescent light emitting layer)
Next, the resistance heating boat containing Compound GD-1, Compound RD-1, and Compound H-2 is energized and heated, and the content of Compound GD-1 in the formed layer is 17% by volume, RD- 1 was co-deposited on the fluorescent light emitting layer at a deposition rate of 0.1 nm / second so that the content of 1 was 0.8% by volume and the content of Compound H-2 was 82.2% by volume. A phosphorescent layer having a yellow color was formed.

(Formation of electron transport layer)
Next, the resistance heating boat containing the compound E-1 is energized and heated, the compound E-1 is deposited on the phosphorescent light emitting layer at a deposition rate of 0.1 nm / second, and an electron transport layer having a layer thickness of 30 nm is formed. Formed.

(Formation of electron injection layer)
Next, a resistance heating boat containing lithium fluoride was energized and heated, and lithium fluoride was deposited on the electron transport layer at a deposition rate of 0.05 nm / second to form an electron injection layer having a layer thickness of 1 nm.
In this way, a light emitting functional layer was formed.

(Formation of cathode)
Furthermore, aluminum was vapor-deposited by a vapor deposition method to form a cathode having a thickness of 10 nm.

(Sealing)
100 parts by mass of “Opanol B50 (manufactured by BASF, Mw: 340,000)” as a polyisobutylene resin, 30 parts by mass of “Nisseki Polybutene Grade HV-1900 (manufactured by Nippon Oil Corporation, Mw: 1900)” as a polybutene resin, hindered amine 0.5 part by weight of “TINUVIN765 (manufactured by BASF Japan, having tertiary hindered amine group)” as a light stabilizer, and “IRGANOX1010 (manufactured by BASF Japan, β of hindered phenol group, as hindered phenol antioxidant) 0.5 parts by mass of both units having a tertiary butyl group) and 50 parts by mass of “Eastotac H-100L Resin (manufactured by Eastman Chemical Co.)” as a cyclic olefin polymer are dissolved in toluene. And an adhesive having a solid content of about 25% by mass The Narubutsu was prepared.

Next, the surface of the aluminum foil side of the 50 μm thick polyethylene terephthalate film on which the aluminum (Al) foil having a thickness of 100 μm was laminated was colored with carbon black to prepare a sealing substrate. Next, the prepared adhesive composition solution is applied to the aluminum side of the sealing substrate so that the thickness of the adhesive layer formed after drying is 20 μm, and dried at 120 ° C. for 2 minutes for adhesion. A layer was formed. Next, as a release sheet, a release treatment surface of a polyethylene terephthalate film subjected to a release treatment with a thickness of 38 μm was attached to the formed adhesive layer surface to produce a sealing member.
The sealing member produced by the above-described method is prepared in a size of 40 mm × 50 mm, the release sheet is removed under a nitrogen atmosphere, dried on a hot plate heated to 120 ° C. for 10 minutes, and then lowered to room temperature. After confirming the above, it was laminated so as to completely cover the formed cathode, and heated at 90 ° C. for 10 minutes and sealed.
Thus, the organic EL element 1 was produced.

<< Production of Organic EL Element 2 >>
In the production of the organic EL element 1, the organic EL element 2 was produced in the same manner except that the thickness of the conductive layer was changed to 15 nm.

<< Production of Organic EL Element 3 >>
In the production of the organic EL element 1, the organic EL element 3 was produced in the same manner except that a transparent substrate showing the production method below was used.

  As a flexible transparent substrate, a commercially available polyethylene terephthalate film (PET film) substrate (thickness 125 μm) is selected, and on the substrate, referring to Example 1 of JP2012-116101A, A gas barrier layer was formed.

Specifically, a UV curable organic material manufactured by JSR Corporation on one side of a polyethylene terephthalate film (Teijin DuPont Films Co., Ltd., ultra-high transparency PET Type K) having a width of 500 mm and a thickness of 125 μm, which is easily bonded on both sides. / Inorganic hybrid hard coat material OPSTAR Z7535 was applied so that the layer thickness after application and drying was 4 μm, then dried at 80 ° C. for 3 minutes, and then cured at 1.0 J / cm ² , air Curing was performed using a high-pressure mercury lamp in an atmosphere to form a bleed-out prevention layer.

Subsequently, a UV curable organic / inorganic hybrid hard coat material OPSTAR Z7501 manufactured by JSR Corporation is applied to the opposite surface of the PET film so that the layer thickness after application and drying is 4 μm, and then drying conditions; 80 After drying at 3 ° C. for 3 minutes, curing was carried out using a high-pressure mercury lamp in an air atmosphere at 1.0 J / cm ² to form a flat layer.

The maximum cross-sectional height Rt (p) of the obtained flat layer was 16 nm with a surface roughness specified by JIS B 0601.
The surface roughness was measured using an AFM (Atomic Force Microscope) SPI3800N DFM manufactured by SII. The measurement range for one time was 10 μm × 10 μm, the measurement location was changed, and the measurement was performed three times. The average of the Rt values obtained in each measurement was taken as the measurement value.

  The total thickness of the PET film on which the bleed-out preventing layer and the flat layer were formed as described above was 133 μm.

  Next, the first gas barrier layer is applied to the surface of the flat layer of the PET film with a coating solution containing an inorganic precursor compound using a vacuum extrusion type coater so that the dry layer thickness is 150 nm. did.

  The coating solution containing the inorganic precursor compound contains a non-catalytic perhydropolysilazane 20% by mass dibutyl ether solution (AZ Electronic Materials Co., Ltd. Aquamica NN120-20) and an amine catalyst in an amount of 5% by mass. Perhydropolysilazane 20% by mass dibutyl ether solution (Aquamica NAX120-20 manufactured by AZ Electronic Materials Co., Ltd.) was mixed and used, and the amine catalyst was adjusted to 1% by mass of solids. A 5% by weight dibutyl ether solution was prepared by dilution.

  After coating, the film was dried under the conditions of a drying temperature of 80 ° C., a drying time of 300 seconds, and a dew point of 5 ° C. in a dry atmosphere.

  After drying, the PET film was gradually cooled to 25 ° C., and the coating surface was subjected to modification treatment by irradiation with vacuum ultraviolet rays under the following modification treatment conditions using the following vacuum ultraviolet irradiation device. A Xe excimer lamp having a double tube structure that irradiates vacuum ultraviolet rays of 172 nm was used as a light source of the vacuum ultraviolet irradiation apparatus.

<Vacuum ultraviolet irradiation device>
Excimer irradiation device MODEL: MECL-M-1-200, wavelength 172 nm, manufactured by M.D.

<Reforming treatment conditions>
Excimer light intensity 3J / cm ² (172nm)
Stage heating temperature 100 ° C
Oxygen concentration in the irradiation device

  After the modification treatment, the PET film on which the gas barrier layer was formed was dried in the same manner as described above, and further subjected to the second modification treatment under the same conditions to form a gas barrier layer having a dry layer thickness of 150 nm.

Next, in the same manner as the first gas barrier layer, a second gas barrier layer was formed on the first gas barrier layer to produce a PET film having a gas barrier layer.
In this way, a transparent substrate was produced.

<< Production of Organic EL Element 4 >>
In the production of the organic EL device 1, a gas having a bromine concentration of 99.9% by volume was introduced into the second vacuum chamber at a rate of 0.1 cc / min during the formation of the conductive layer to form a conductive layer having a thickness of 10 nm. An organic EL element 4 was produced in the same manner except that it was formed.

<< Preparation of organic EL element 5 >>
In the production of the organic EL element 1, an organic EL element 5 was produced in the same manner except that the conductive layer was formed as follows.
Before forming the intermediate layer on the transparent substrate, a resistance heating boat containing powdered iodine is attached to the second vacuum tank. Then, when silver is deposited in the second vacuum chamber after the intermediate layer is formed, simultaneously heating and heating the resistance heating boat containing iodine, the iodine is co-deposited on the intermediate layer at a deposition rate of 0.002 nm / second. A conductive layer having a layer thickness of 10 nm was formed.

<< Production of Organic EL Element 6 >>
In the production of the organic EL element 1, a gas having a chlorine concentration of 99.9% by volume was introduced into the second vacuum chamber at a rate of 0.1 cc / min during the formation of the conductive layer to form a conductive layer having a thickness of 10 nm. An organic EL element 6 was produced in the same manner except that it was formed.

<< Preparation of organic EL element 7 >>
In the production of the organic EL device 1, a gas having a sulfur concentration of 99.9% by volume was introduced into the second vacuum chamber at a rate of 0.1 cc / min during the formation of the conductive layer to form a conductive layer having a thickness of 10 nm. An organic EL element 7 was produced in the same manner except that it was formed.

<< Production of Organic EL Element 8 >>
In the production of the organic EL element 1, a gas having an oxygen concentration of 99.9% by volume was introduced into the second vacuum chamber at a rate of 0.1 cc / min during the formation of the conductive layer to form a conductive layer having a thickness of 10 nm. An organic EL element 8 was produced in the same manner except that it was formed.

<< Production of Organic EL Element 9 >>
In the production of the organic EL element 1, the organic EL element 9 was produced in the same manner except that the conductive layer was formed as follows.
After forming the intermediate layer, silver was vapor-deposited to form a silver layer having a thickness of 10 nm, and then the pressure in the second vacuum chamber was increased to atmospheric pressure, and the second vacuum chamber was opened to take in air. Then, after 30 seconds, the second vacuum chamber is closed again, the vacuum is drawn until the degree of vacuum of the second vacuum chamber becomes 4.0 × 10 ⁻⁴ Pa, and the substrate holder is held in the first vacuum chamber while maintaining the vacuum state. Moved to. In this way, a conductive layer having a layer thickness of 10 nm was formed.

<< Production of Organic EL Element 10 >>
In the production of the organic EL element 9, the organic EL element 10 was produced in the same manner except that the standby time from the opening of the second vacuum chamber to the closing of the second vacuum chamber was changed to 10 minutes.

<< Production of Organic EL Element 11 >>
In the production of the organic EL element 9, the organic EL element 11 was produced in the same manner except that the standby time from the opening of the second vacuum chamber to the closing thereof was changed to 15 minutes.

<< Production of Organic EL Element 12 >>
In the production of the organic EL element 9, the organic EL element 12 was produced in the same manner except that the waiting time from when the second vacuum chamber was opened to when it was closed again was changed to 30 minutes.

<< Production of Organic EL Element 13 >>
In the production of the organic EL element 1, an organic EL element 13 was produced in the same manner except that the conductive layer was formed as follows.
After forming the intermediate layer, silver is deposited to form a silver layer having a thickness of 10 nm, and then a mixed gas containing water and nitrogen (2% by volume) until the degree of vacuum of the second vacuum chamber becomes 1.0 × 10 ⁻³ Pa. Nitrogen gas containing water was introduced, and the system was kept in that state for 10 minutes. Thereafter, the vacuum was drawn until the degree of vacuum of the second vacuum chamber became 4.0 × 10 ⁻⁴ Pa, and the substrate holder was moved to the first vacuum chamber while keeping the vacuum state. In this way, a conductive layer having a layer thickness of 10 nm was formed.

<< Production of Organic EL Element 14 >>
In the production of the organic EL element 13, the organic EL element 14 was produced in the same manner except that the thickness of the silver layer was changed to 15 nm and a conductive layer having a layer thickness of 15 nm was formed.

<< Production of Organic EL Element 15 >>
In the production of the organic EL element 13, a mixed gas containing water and nitrogen (nitrogen gas containing 2% by volume of water) was introduced until the degree of vacuum in the second vacuum chamber was 1.0 × 10 ⁻³ Pa. The organic EL element 15 was produced in the same manner except that it waited for 30 minutes in that state.

<< Preparation of Organic EL Element 16 >>
In the production of the organic EL element 13, a mixed gas containing water and nitrogen (nitrogen gas containing 2% by volume of water) was introduced until the degree of vacuum in the second vacuum chamber was 1.0 × 10 ⁻³ Pa. The organic EL element 16 was produced in the same manner except that it waited for 1 hour in this state.

<< Preparation of Organic EL Element 17 >>
In the production of the organic EL element 13, a mixed gas containing water and nitrogen (nitrogen gas containing 2% by volume of water) was introduced until the degree of vacuum in the second vacuum chamber was 1.0 × 10 ⁻³ Pa. The organic EL element 17 was produced in the same manner except that it waited for 1 minute in that state.

<< Production of Organic EL Element 18 >>
In the production of the organic EL element 8, an organic EL element 18 was produced in the same manner except that the transparent substrate used for the production of the organic EL element 3 was used.

<< Preparation of Organic EL Sample 19 >>
In the production of the organic EL element 15, an organic EL element 19 was produced in the same manner except that the transparent substrate used in the production of the organic EL element 3 was used.

<< Production of Organic EL Element 20 >>
In the production of the organic EL element 17, the organic EL element 20 was produced in the same manner except that the transparent substrate used for the production of the organic EL element 3 was used.

<< Production of Organic EL Elements 21-23 >>
In the production of the organic EL element 8, the organic EL element 21 was similarly obtained except that the material of the intermediate layer was changed to the compounds 7, 10, and 40 exemplified as the nitrogen-containing compound (3) as shown in Table 1. ~ 23 were made.

<< Production of Organic EL Element 24 >>
In the production of the organic EL element 13, silver is deposited after forming the intermediate layer to form a silver layer having a thickness of 15 nm, and water and nitrogen are used until the vacuum degree of the second vacuum chamber becomes 1.0 × 10 ⁻³ Pa. An organic EL element 24 was produced in the same manner except that the exhaust was started again immediately after introducing a mixed gas containing nitrogen (nitrogen gas containing 2% by volume of water).

<< Production of Organic EL Element 25 >>
In the production of the organic EL element 13, silver is deposited after forming the intermediate layer to form a silver layer having a thickness of 15 nm, and water and nitrogen are used until the vacuum degree of the second vacuum chamber becomes 1.0 × 10 ⁻³ Pa. An organic EL element 25 was produced in the same manner except that a mixed gas containing nitrogen (nitrogen gas containing 2% by volume of water) was introduced and the system was kept in that state for 10 seconds.

<< Production of Organic EL Element 26 >>
In the production of the organic EL element 13, silver is deposited after forming the intermediate layer to form a silver layer having a thickness of 15 nm, and water and nitrogen are used until the vacuum degree of the second vacuum chamber becomes 1.0 × 10 ⁻³ Pa. An organic EL element 26 was produced in the same manner except that a mixed gas containing nitrogen (nitrogen gas containing 2% by volume of water) was introduced and the system was kept in that state for 30 seconds.

<< Preparation of organic EL element 27 >>
In the production of the organic EL element 9, the organic EL element 27 was produced in the same manner except that a silver layer having a thickness of 15 nm was formed using a sputtering film formation method while introducing Ar gas as a method for forming the silver layer. did.

<< Production of Organic EL Element 28 >>
In the production of the organic EL element 9, an organic EL element 28 was produced in the same manner except that a silver layer having a layer thickness of 15 nm was formed by a vacuum vapor deposition method using electron beam heating as a method for forming the silver layer.

<< Evaluation of Organic EL Elements 1-28 >>
With respect to the produced organic EL elements 1 to 28, changes in voltage and luminance over time were measured. Moreover, the density | concentration of the silver compound contained in the element in each composition was analyzed. The results are shown in Table 2.

(1) Measurement of content of trace amount of element in conductive layer of organic EL element In the production of each of the organic EL elements 1 to 28, the following measuring device was used for the transparent substrate on which only the intermediate layer and the conductive layer were formed. Was used to measure the content of each element under the following measurement conditions to determine the content of each element contained in the conductive layer.

Measuring apparatus: TRIFT-2 (TOF-SIMS, manufactured by US Phi Corp.)
Primary ion: Indium Primary ion acceleration voltage: 15 kV
Primary ion current: 20 nA
Primary ion pulse width: 780 ps (after bunching)
Measurement area: 60 μm square Measurement mass range: 0.5 to 1000

(2) Voltage and luminance fluctuation over time of driving In the evaluation of voltage fluctuation and luminance fluctuation during driving, the current density of each of the organic EL elements 1 to 28 is fixed at 5.0 mA / cm ² , and the initial current-carrying performance is 100 The rate of change in voltage (V) and luminance (cd / m ² ) after the lapse of time was derived. The results were evaluated according to the following criteria. A spectral radiance meter CS-2000 (manufactured by Konica Minolta) was used for measuring the luminance. In addition, it shows that it is so preferable that the obtained voltage and the change rate of a brightness | luminance are small.
◎: Less than 1% ○: 1% or more and less than 3% △: 3% or more and less than 10% ×: 10% or more

  As shown in Table 2, since the organic EL elements 4 to 28 are provided with a transparent electrode containing an element selected from oxygen, sulfur, bromine, chlorine and iodine as a trace element in the conductive layer, before and after driving. The voltage change rate and the luminance change rate are small values. On the other hand, the organic EL elements 1 to 3 of the comparative example have transparent electrodes that do not contain trace amounts of elements in the conductive layer, and the voltage change rate and luminance change rate before and after driving show large values. . Therefore, according to the present invention, it is possible to provide a transparent electrode in which voltage fluctuation and luminance fluctuation with time are suppressed.

1a conductive layer 1b intermediate layer 10 transparent electrode 100 organic EL element

Claims (5)

A conductive layer, and at least one intermediate layer provided adjacent to the conductive layer,
The said conductive layer contains silver and the element chosen from oxygen, sulfur, bromine, chlorine, and iodine as a trace amount element, The transparent electrode characterized by the above-mentioned.   The transparent electrode according to claim 1, wherein the conductive layer contains 1% by mass or less of the trace element.   The transparent electrode according to claim 1, wherein the conductive layer contains 0.001 to 0.5 mass% of the trace element.   The said electroconductive layer contains 0.001-0.1 mass% of said trace amount elements, The transparent electrode as described in any one of Claim 1- Claim 3 characterized by the above-mentioned.   An organic electroluminescence device comprising the transparent electrode according to any one of claims 1 to 4.

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