JP6366221B2 - Transparent electrode and electronic device - Google Patents

Description

  The present invention relates to a transparent electrode and an electronic device, and more particularly, to a transparent electrode having both conductivity and light transmittance, and an electronic device using the transparent electrode.

  An organic electroluminescent element (so-called organic EL element) using electroluminescence (hereinafter referred to as EL) of an organic material is a thin-film type completely solid element capable of emitting light at a low voltage of several V to several tens V. It has many excellent features such as high brightness, high luminous efficiency, thinness, and light weight. 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 electroluminescent element has a configuration in which a light emitting layer composed of an organic material is sandwiched between two electrodes, and emitted light generated in the light emitting layer passes through the electrode and is extracted outside. For this reason, at least one of the two electrodes is configured as a transparent electrode.

As the transparent electrode, indium tin oxide is _{(SnO 2 -In 2 O 3:} : Indium Tin Oxide ITO) oxide semiconductor-based material such as is commonly used, low by laminating the ITO and silver Studies aiming at resistance have also been made (for example, see Patent Documents 1 and 2 below). However, since ITO uses rare metal indium, the material cost is high, and it is necessary to anneal at about 300 ° C. after film formation in order to reduce resistance. Therefore, a configuration in which a metal material such as silver having high electrical conductivity is thinned, and a configuration in which conductivity is ensured with a thinner film thickness than silver alone by mixing aluminum with silver (for example, the following patent documents) 3).

JP 2002-15623 A Japanese Unexamined Patent Publication No. 2006-164961 JP 2009-151963 A

  However, it has been difficult to achieve both sufficient conductivity and light transmittance even with a transparent electrode composed of silver or aluminum having high electrical conductivity.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a transparent electrode having sufficient conductivity and light transmittance, and to provide an electronic device whose performance is improved by using this transparent electrode.

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

1. A transparent electrode comprising an aluminum-containing layer and an electrode layer mainly composed of silver provided adjacent to the aluminum-containing layer.

2. 2. The transparent electrode according to 1, wherein the aluminum-containing layer is provided between the electrode layer and a high refractive index layer made of a metal oxide.

3. 3. The transparent electrode according to ₂ , wherein the high refractive index layer is composed of titanium dioxide (TiO ₂ ).

4). 4. The transparent electrode according to any one of 1 to 3, wherein the aluminum-containing layer has a thickness of 5 nm or less.

5. The transparent electrode according to any one of 1 to 4, wherein the aluminum-containing layer is made of aluminum.

6). The transparent electrode according to any one of 1 to 4, wherein the aluminum-containing layer is made of an alloy containing aluminum as a main component.

7). The transparent electrode according to any one of 1 to 4, wherein the aluminum-containing layer is composed of an aluminum oxide.

8). 5. The transparent electrode according to any one of 1 to 4, wherein the aluminum-containing layer is made of aluminum nitride.

9. The electronic device which has a transparent electrode in any one of said 1-8.

10. 10. The electronic device according to 9, wherein the electronic device is an organic electroluminescent element.

  The transparent electrode configured as described above has a configuration in which an electrode layer mainly composed of silver is provided adjacent to an aluminum-containing layer. Thereby, the silver atom which comprises an electrode layer interacts with the aluminum atom which comprises an aluminum containing layer, the diffusion distance in the aluminum containing layer surface of a silver atom reduces, and aggregation of silver is suppressed. For this reason, the electrode layer is generally a single-layer growth type (Frank-van der Merwe: FM type) that is easily isolated in an island shape by film growth of a nuclear growth type (Volume-Weber: VW type). ) Film growth. Accordingly, an electrode layer having a uniform film thickness can be obtained even though the film thickness is small. As a result, it is possible to obtain a transparent electrode in which conductivity is ensured by having a uniform film thickness while ensuring light transmittance by having a thin film thickness.

  As described above, according to the present invention, it is possible to achieve both improvement in conductivity and light transmission in the transparent electrode, and improvement in performance of an electronic device using the transparent electrode. It becomes possible.

It is a cross-sectional schematic diagram which shows the structure of the transparent electrode of this invention. It is a section lineblock diagram showing the 1st example of an organic electroluminescent element using a transparent electrode of the present invention. It is a cross-sectional block diagram which shows the 2nd example of the organic electroluminescent element using the transparent electrode of this invention. It is a cross-sectional block diagram which shows the 3rd example of the organic electroluminescent element using the transparent electrode of this invention. It is a cross-sectional block diagram which shows the 4th example of the organic electroluminescent element using the transparent electrode of this invention. 4 is a cross-sectional configuration diagram illustrating a bottom emission type organic electroluminescence device manufactured in Example 2. FIG.

Hereinafter, embodiments of the present invention will be described in the following order based on the drawings.
1. 1. Transparent electrode 2. Use of transparent electrode First example of organic electroluminescence device (bottom emission type)
4). Second example of organic electroluminescence device (top emission type)
5. Third example of organic electroluminescence device (double-sided light emission type)
6). Fourth example of organic electroluminescence device (reverse stacking configuration)
7). Use of organic electroluminescence device8. Lighting device-1
9. Illumination device-2
In addition, in each embodiment, the same code | symbol is attached | subjected to a common component, and the overlapping description is abbreviate | omitted.

<< 1. Transparent electrode >>
FIG. 1 is a schematic cross-sectional view showing the configuration of the transparent electrode of the embodiment. As shown in this figure, the transparent electrode 1 has a three-layer structure in which a high refractive index layer H, an aluminum-containing layer 1a, and an electrode layer 1b are laminated. For example, the high refractive index layer H, The aluminum-containing layer 1a and the electrode layer 1b are provided in this order. Among these, the electrode layer 1b which is an electrode part in the transparent electrode 1 is characterized by being composed mainly of silver (Ag). Further, the aluminum-containing layer 1a adjacent to the electrode layer 1b is characterized in that it contains aluminum that is stably bonded to silver which is the main material constituting the electrode layer 1b.

  Below, a detailed structure is demonstrated in order of the base material 11 with which the transparent electrode 1 of such a laminated structure is provided, the high refractive index layer H which comprises the transparent electrode 1, the aluminum containing layer 1a, and the electrode layer 1b. In addition, the transparency of the transparent electrode 1 of the present invention means that the light transmittance at a wavelength of 550 nm is 50% or more.

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

  Examples of the glass include silica glass, soda-lime silica glass, lead glass, borosilicate glass, and alkali-free glass. From the viewpoints of adhesion, durability, and smoothness to the aluminum-containing layer 1a, the surface of these glass materials is subjected to physical treatment such as polishing, a coating made of an inorganic material or an organic material, if necessary, A hybrid film combining these films is formed.

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

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

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

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

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

<High refractive index layer H>
The high refractive index layer H is a layer made of a metal oxide provided with the aluminum-containing layer 1a sandwiched between the electrode layer 1b. The refractive index of the high refractive index layer H is 2.0 or more at a wavelength of 550 nm. For such a high refractive index layer H, a metal oxide or the like is mainly used. For example, titanium dioxide (TiO ₂ : n = 2.3 to 2.4), zirconium oxide (ZrO ₂ : n = 2.4). ), Cadmium oxide (CdO: n = 2.49), indium tin oxide (ITO: n = 2.1 to 2.2), hafnium oxide (HfO ₂ : n = 2.1), tantalum pentoxide (Ta ₂₎ O ₅ : n = 2.16), niobium oxide (Nb ₂ O ₅ : n = 2.2 to 2.4), cerium oxide (CeO ₂ : n = 2.2), etc. High refractive index material is used.

<Aluminum-containing layer 1a>
The aluminum-containing layer 1a is a layer configured using, for example, aluminum or an aluminum-containing compound. Since the aluminum-containing layer 1a interacts with aluminum atoms and silver atoms constituting the adjacent electrode layer 1b, the aluminum content is large in the entire layer, particularly on the interface side with the electrode layer 1b. Is preferred.

Examples of the aluminum-containing compound include aluminum alloys, aluminum oxides, and aluminum nitrides. Among these, the aluminum alloy is an alloy containing aluminum as a main component, and the aluminum content is preferably 50 atm% or more, and examples include aluminum titanium (TiAl). Examples of the aluminum oxide include aluminum oxide (Al ₂ O ₃ ). Examples of the aluminum nitride include aluminum nitride (AlN).

  Moreover, the aluminum containing layer 1a should just be comprised using the aluminum or the aluminum containing compound mentioned above, may be comprised using 2 or more types of these, or may contain the material which does not contain aluminum. . As a material not containing aluminum, silver (Ag), magnesium (Mg), copper (Cu), indium (In), iridium (Ir), lithium (Li), or the like is used.

  It is important that the aluminum-containing layer 1a as described above has a thin film thickness that does not hinder the light transmittance of the transparent electrode 1, and a preferable film thickness is 5 nm or less. On the other hand, the aluminum-containing layer 1a needs to have a film thickness that can ensure the conductivity of the transparent electrode 1, for example, has a film thickness that is at least a single-layer stack of aluminum atoms, and is a continuous film. Is preferred.

  In addition, although the film-forming method of such an aluminum content layer 1a is not specifically limited, a vapor deposition method (EB, resistance heating) and a sputtering method are applied preferably.

<Electrode layer 1b>
The electrode layer 1b is a layer composed mainly of silver, is composed of silver or an alloy composed mainly of silver, and is a layer formed adjacent to the aluminum-containing layer 1a. Such an electrode layer 1 b functions as a substantial electrode portion of the transparent electrode 1.

  As a method for forming the electrode layer 1b, a wet process such as a coating method, an inkjet method, a coating method, or a dip method, a dry process such as a vapor deposition method (resistance heating, EB method, etc.), a sputtering method, a CVD method, or the like is used. And the like. Of these, vapor deposition (resistance heating, EB, etc.) or sputtering is preferably applied. In addition, the electrode layer 1b is formed on the aluminum-containing layer 1a, so that it has sufficient conductivity even without high-temperature annealing after the film formation. The film may be subjected to a high temperature annealing treatment after the film.

  For example, an alloy containing silver (Ag) as a main component constituting the electrode layer 1b is silver magnesium (AgMg), silver copper (AgCu), silver palladium (AgPd), silver palladium copper (AgPdCu), silver indium (AgIn). Silver neodymium (AgNd), silver carbon (AgC), silver zinc (AgZn), silver aluminum (AgAl), and the like.

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

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

  The transparent electrode 1 having a laminated structure composed of the high refractive index layer H, the aluminum-containing layer 1a, and the electrode layer 1b provided adjacent to the high refractive index layer H as described above is covered with a protective film at the top of the electrode layer 1b. Or another conductive layer may be laminated. In this case, it is preferable that the protective film and the conductive layer have light transmittance so as not to impair the light transmittance of the transparent electrode 1. Moreover, it is good also as a structure which provided the layer as needed also under the high refractive index layer H, ie, between the high refractive index layer H and the base material 11. FIG.

<Effect of transparent electrode 1>
The transparent electrode 1 configured as described above has a configuration in which an electrode layer 1b mainly composed of silver is provided adjacent to the aluminum-containing layer 1a. Thus, when the electrode layer 1b is formed adjacent to the aluminum-containing layer 1a, the silver atoms constituting the electrode layer 1b interact with the aluminum atoms constituting the aluminum-containing layer 1a, so that the aluminum content of silver atoms The diffusion distance on the surface of the layer 1a is reduced, and silver aggregation is suppressed. Therefore, in general, a silver thin film that is easily isolated in an island shape by film growth of a nuclear growth type (Volume-Weber: VW type) is a single-layer growth type (Frank-van der Merwe: FM type). As a result, a film is formed. Therefore, the electrode layer 1b having a uniform film thickness can be obtained even though the film thickness is small. As a result, it is possible to reliably obtain the electrode layer 1b in which conductivity is ensured by having a uniform film thickness while ensuring light transmittance by having a thin film thickness, and a transparent electrode using silver It is possible to achieve both the improvement in conductivity and the improvement in light transmission in 1.

  The transparent electrode 1 has a high refractive index layer H in addition to the aluminum-containing layer 1a and the electrode layer 1b. Thereby, the reflection which arises in the electrode layer 1b which has silver as a main component is suppressed. As a result, the light transmittance in the transparent electrode 1 is further improved.

  Further, such a transparent electrode 1 is low in cost because it does not use indium (In), which is a rare metal, and has excellent long-term reliability because it does not use a chemically unstable material such as ZnO. Yes.

  In addition, although the structure laminated | stacked in order of the high refractive index layer H, the aluminum containing layer 1a, and the electrode layer 1b was demonstrated as an example of the transparent electrode 1, it is not restricted to this. That is, any arrangement relationship in which the aluminum-containing layer 1a is sandwiched between the electrode layer 1b and the high-refractive index layer H may be used regardless of the order of lamination. For example, the transparent electrode 1 may be configured by laminating the electrode layer 1b, the aluminum-containing layer 1a, and the high refractive index layer H in this order. In this case, since the high refractive index layer H using a metal oxide is laminated on the electrode layer 1b containing silver as a main component via the aluminum-containing layer 1a, oxygen atoms and silver atoms that are difficult to bond are combined. Can be avoided. For this reason, compared with the case where the high refractive index layer H is directly formed on the electrode layer 1b, the high refractive index layer H with good film quality can be formed. Therefore, the high refractive index layer H can satisfactorily perform the function of suppressing the reflection generated in the electrode layer 1b, and the light transmittance in the transparent electrode 1 can be further improved.

  Moreover, although the transparent electrode 1 of the three-layer structure was demonstrated as shown in FIG. 1, the transparent electrode of this invention is a two-layer structure by the aluminum containing layer 1a and the electrode layer 1b except the high refractive index layer H. There may be. As will be described later in Examples, it has been confirmed that even a transparent electrode having such a two-layer structure can realize a transparent electrode that achieves both improved conductivity and improved light transmission. Further, it has been confirmed that the light transmittance is further improved by adopting a three-layer structure to which the high refractive index layer H is added.

≪2. Applications of transparent electrodes >>
The transparent electrode 1 having the above-described configuration can be used for various electronic devices. Examples of electronic devices include organic electroluminescent elements, LEDs (Light Emitting Diodes), liquid crystal elements, solar cells, touch panels, etc. As electrode members that require light transmission in these electronic devices, A transparent electrode 1 can be used.
Hereinafter, as an example of the application, an embodiment of an organic electroluminescent element using transparent electrodes as an anode and a cathode will be described.

≪3. First example of organic electroluminescence device (bottom emission type) >>
<Configuration of organic electroluminescent element EL-1>
FIG. 2 is a cross-sectional configuration diagram illustrating a first example of an organic electroluminescent element using the transparent electrode 1 described above as an example of the electronic device of the present invention. The configuration of the organic electroluminescent element will be described below based on this figure.

  The organic electroluminescent element EL-1 shown in FIG. 2 is provided on the transparent substrate 13 ′, and in order from the transparent substrate 13 ′ side, the transparent electrode 1 serving as the anode, the light emitting functional layer 3, and the counter electrode serving as the cathode. 5-1 are stacked. Of these, the transparent electrode 1 is characterized in that the transparent electrode 1 of the present invention described above is used. Therefore, the organic electroluminescent element EL-1 is configured as a bottom emission type in which generated light (hereinafter referred to as emitted light h) is extracted from at least the transparent substrate 13 'side.

  Further, the overall layer structure of the organic electroluminescent element EL-1 is not limited and may be a general layer structure. Here, the transparent electrode 1 is disposed on the anode (ie, anode) side, and the electrode layer 1b mainly functions as an anode, while the counter electrode 5-1 functions as a cathode (ie, 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 on the transparent electrode 1 serving as the anode. Of these, it is essential to have the light emitting layer 3c composed of 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. Among these light emitting functional layers 3, for example, the electron injection layer 3e may be made of an inorganic material.

  In addition to these layers, the light-emitting functional layer 3 may be laminated with a hole blocking layer, an electron blocking layer, and the like as necessary. Furthermore, the light emitting layer 3c has each color light emitting layer for generating emitted light in each wavelength region, and each color light emitting layer may be laminated through a non-light emitting intermediate layer to form a light emitting layer unit. good. The intermediate layer may function as a hole blocking layer and an electron blocking layer. Further, the counter electrode 5-1 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 1 and the counter electrode 5-1 becomes a light emitting region in the organic electroluminescent element EL-1.

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

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

  Hereinafter, the details of the main layers for constituting the organic electroluminescent element EL-1 described above are as follows: the transparent substrate 13 ′, the transparent electrode 1, the counter electrode 5-1, the light emitting layer 3c of the light emitting functional layer 3, and the light emitting functional layer 3. The other layers, the auxiliary electrode, and the sealing material will be described in this order. Thereafter, a method for producing the organic electroluminescent element EL-1 will be described.

[Transparent substrate 13 ']
As the transparent substrate 13 ′, a transparent substrate having light permeability is used among the substrates on which the transparent electrode 1 of the present invention described above is provided.

[Transparent electrode 1 (anode side)]
The transparent electrode 1 is the transparent electrode 1 of the present invention described above, and has a configuration in which a high refractive index layer H, an aluminum-containing layer 1a, and an electrode layer 1b are sequentially formed from the transparent substrate 13 ′ side. Here, in particular, the electrode layer 1b constituting the transparent electrode 1 is a substantial anode.

[Counter electrode 5-1 (cathode)]
The counter electrode 5-1 is an electrode film that functions as a cathode for supplying electrons to the light emitting functional layer 3, 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 5-1 can be produced by forming a thin film of these conductive materials by a method such as vapor deposition or sputtering. Further, the sheet resistance as the counter electrode 5-1 is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 5 nm to 5 μm, preferably 5 nm to 200 nm.

  If the organic electroluminescent element EL-1 is a double-sided light emitting type that takes out the emitted light h from the counter electrode 5-1 side, a conductive material having good light transmittance among the conductive materials described above is used. The counter electrode 5-1 may be configured by selection.

[Light emitting layer 3c]
The light emitting layer 3c used in the present invention contains, for example, a phosphorescent compound as a light emitting material.

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

  There is no restriction | limiting in particular in the structure as such a light emitting layer 3c, if the light emitting material contained satisfies the light emission requirements. Moreover, there may be a plurality of layers having the same emission spectrum and emission maximum wavelength. In this case, it is preferable to have a non-light emitting intermediate layer (not shown) between the light emitting layers 3c.

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

  In the case of the light emitting layer 3c 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 blue, green, and red light emitting colors, there is no particular limitation on the relationship between the film thicknesses of the blue, green, and red light emitting layers.

  The light emitting layer 3c 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. be able to.

  The light emitting layer 3c 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 3c.

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

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

  As a host compound, a well-known host compound may be used independently, or multiple types may be used. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the efficiency of the organic electroluminescent element EL-1 can be increased. 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 high molecular compound having a polymerizable group such as a vinyl group or an epoxy group (evaporation polymerizable light emitting host). .

  As the known host compound, a compound having a hole transporting ability and an electron transporting ability, preventing an increase in emission wavelength, and having a high Tg (glass transition temperature) compound is preferable. The glass transition point (Tg) here is a value obtained by a method based on JIS-K-7121 using DSC (Differential Scanning Colorimetry).

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

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

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

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

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

  There are two types of light emission principles of the phosphorescent compound. One is that recombination of carriers occurs on the host compound to which carriers are transported to generate an excited state of the host compound, and this energy is transferred to the phosphorescent compound to obtain light emission from the phosphorescent compound. The other is a carrier trap type in which the phosphorescent compound becomes a carrier trap, and carriers are recombined on the phosphorescent compound to emit light from the phosphorescent compound. In either case, it is a condition that the excited state energy of the phosphorescent compound is lower than the excited state energy of the host compound.

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

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

  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 3c.

(Compound represented by the general formula (1))
The compound (phosphorescent compound) contained in the light emitting layer 3c is preferably a compound represented by the following general formula (1).

  The phosphorescent compound represented by the general formula (1) (also referred to as a phosphorescent metal complex) is preferably contained as a light emitting dopant in the light emitting layer 3c of the organic electroluminescent element EL-1. However, it may be contained in a light emitting functional layer other than the light emitting layer 3c.

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

  In the general formula (1), P and Q each represent a carbon atom or a nitrogen atom.

  In the general formula (1), the aromatic hydrocarbon ring that A1 forms with P—C includes a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a chrysene ring, Naphthacene ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, Examples include a picene ring, a pyrene ring, a pyranthrene ring, and an anthraanthrene ring.

  These rings may further have a substituent exemplified below. 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 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 substituted 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, Nonoxy 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, dimethylaminosulfonyl group) 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, phenyl group Carbonyloxy group, etc.), amide groups (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonyl) Amino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexyl) Aminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl Bonyl 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 called piperidinyl group), 2,2,6,6 -Tetramethylpiperidinyl group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluoro) Phenyl group, etc.), cyano group Nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphate ester 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. In addition, a plurality of these substituents may be bonded to each other to form a ring.

  In the general formula (1), as the aromatic heterocycle formed by A1 together with PC, furan ring, thiophene ring, oxazole ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, Benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring, azacarbazole A ring etc. are mentioned.

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

  These rings may further have the substituents exemplified above.

  In the general formula (1), the aromatic heterocycle formed by A2 together with QN includes an oxazole ring, an oxadiazole ring, an oxatriazole ring, an isoxazole ring, a tetrazole ring, a thiadiazole ring, a thiatriazole ring, Examples include a thiazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, a pyrazole ring, and a triazole ring.

  These rings may further have the substituents exemplified above.

  In the general formula (1), P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2.

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

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

  In the general formula (1), M1 is a transition metal element of group 8 to group 10 (also simply referred to as a transition metal) in the periodic table, and iridium is particularly preferable.

(Compound represented by the general formula (2))
Among the compounds represented by the general formula (1), a compound represented by the following general formula (2) is more preferable.

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

  In the general formula (2), examples of the hydrocarbon ring group represented by Z include a non-aromatic hydrocarbon ring group and an aromatic hydrocarbon ring group, and examples of the non-aromatic hydrocarbon ring group include a cyclopropyl group. , Cyclopentyl group, cyclohexyl group and the like. These groups may be unsubstituted or may have the substituent exemplified in the general formula (1).

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

  These groups may be unsubstituted or may have the substituents exemplified in the general formula (1).

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

  These groups may be unsubstituted or may have the substituents exemplified in the general formula (1).

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

  These groups may be unsubstituted or may have the substituents exemplified in the general formula (1).

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

  In the general formula (2), the aromatic hydrocarbon ring that A1 forms with P—C includes a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a chrysene ring, and a naphthacene ring. , Triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring , Pyrene ring, pyranthrene ring, anthraanthrene ring and the like.

  These rings may further have the substituent exemplified in the general formula (1).

  In the general formula (2), the aromatic heterocycle formed by A1 together with P—C includes furan ring, thiophene ring, oxazole ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzo Imidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring, carboline ring, And azacarbazole ring.

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

  These rings may further have the substituent exemplified in the general formula (1).

  In -C (R01) = C (R02)-, -N = C (R02)-, and -C (R01) = N- represented by A3 in the general formula (2), each represented by R01 and R02 These substituents are synonymous with the substituents exemplified as R11 and R12 in the general formula (1).

  In the general formula (2), examples of the bidentate ligand represented by P1-L1-P2 include phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabole, acetylacetone, and picolinic acid. .

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

  In General Formula (2), Group 8 to Group 10 transition metal elements in the periodic table of elements represented by M1 (also simply referred to as transition metals) in General Formula (1) in the periodic table of elements represented by M1 It is synonymous with the transition metal element of Group 8-10.

(Compound represented by the general formula (3))
One preferred embodiment of the compound represented by the general formula (2) is a compound represented by the following general formula (3).

In the general formula (3), R ₀₃ represents a substituent, R ₀₄ represents a hydrogen atom or a substituent, and a plurality of R ₀₄ may be bonded to each other to form a ring. n01 represents an integer of 1 to 4. R ₀₅ represents a hydrogen atom or a substituent, and a plurality of R ₀₅ may be bonded to each other to form a ring. n02 represents an integer of 1 to 2. R ₀₆ represents a hydrogen atom or a substituent, and may combine with each other to form a ring. n03 represents an integer of 1 to 4. Z1 represents an atomic group necessary for forming a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocycle together with C—C. Z2 represents an atomic group necessary for forming a hydrocarbon ring group or a heterocyclic group. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element in the periodic table. R ₀₃ and R ₀₆ , R ₀₄ and R _06, and R ₀₅ and R ₀₆ may be bonded to each other to form a ring.

In General Formula (3), each of the substituents represented by R ₀₃ , R ₀₄ , R ₀₅ , and R ₀₆ may have the substituent exemplified in General Formula (1).

  In the general formula (3), examples of the 6-membered aromatic hydrocarbon ring formed by Z1 together with C—C include a benzene ring.

  These rings may further have the substituent exemplified in the general formula (1).

  In the general formula (3), examples of the 5-membered or 6-membered aromatic heterocycle formed by Z1 together with C—C include an oxazole ring, an oxadiazole ring, an oxatriazole ring, an isoxazole ring, a tetrazole ring, and a thiadiazole. And a ring, a thiatriazole ring, an isothiazole ring, a thiophene ring, a furan ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, a pyrazole ring, and a triazole ring.

  These rings may further have the substituent exemplified in the general formula (1).

  In the general formula (3), examples of the hydrocarbon ring group represented by Z2 include a non-aromatic hydrocarbon ring group and an aromatic hydrocarbon ring group, and examples of the non-aromatic hydrocarbon ring group include a cyclopropyl group. , Cyclopentyl group, cyclohexyl group and the like. These groups may be unsubstituted or may have the substituent exemplified in the general formula (1).

  Examples of the aromatic hydrocarbon ring group (also referred to as aromatic hydrocarbon group, aryl group, etc.) include, for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl. Group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group and the like. These groups may be unsubstituted or may have the substituents exemplified in the general formula (1).

  In the general formula (3), examples of the heterocyclic group represented by Z2 include a non-aromatic heterocyclic group and an aromatic heterocyclic group. Examples of the non-aromatic heterocyclic group include an epoxy ring and an aziridine group. Ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε- Caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydropyran ring, 1,3-dioxane ring, 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine Ring, thiomorpholine-1,1-dioxy And groups derived from a dodo ring, a pyranose ring, a diazabicyclo [2,2,2] -octane ring, and the like. These groups may be unsubstituted or may have the substituent exemplified in the general formula (1).

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

  These rings may be unsubstituted and may further have the substituent exemplified in the general formula (1).

  In the general formula (3), the group formed by Z1 and Z2 is preferably a benzene ring.

  In the general formula (3), the bidentate ligand represented by P1-L1-P2 has the same meaning as the bidentate ligand represented by P1-L1-P2 in the general formula (1). .

  In the general formula (3), the transition metal element of group 8 to group 10 in the periodic table of elements represented by M1 is the transition of group 8 to group 10 in the periodic table of elements represented by M1 in general formula (1). Synonymous with metal element.

  The phosphorescent compound can be appropriately selected from known materials used for the light emitting layer 3c of the organic electroluminescent element EL-1.

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

  Specific examples (Pt-1 to Pt-3, A-1, Ir-1 to Ir-50) of the phosphorescent compound according to the present invention are shown below, but the present invention is not limited thereto. In these compounds, m and n represent the number of repetitions.

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

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

[Injection layer: hole injection layer 3a, electron injection layer 3e]
The injection layer is a layer provided between the electrode and the light emitting layer 3c in order to lower the driving voltage and improve the light emission luminance. “The organic EL element and the forefront of its industrialization (November 30, 1998, NT. 2) Chapter 2 “Electrode Materials” (pages 123 to 166) of the 2nd volume of “S. Co., Ltd.”, which includes a hole injection layer 3a and an electron injection layer 3e.

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

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

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

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

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

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

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole, as well as two of those described in US Pat. No. 5,061,569 Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the like.

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

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

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

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

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

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

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

  In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq3), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum. Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metals of these metal complexes are In, Mg, A metal complex replaced with Cu, Ca, Sn, Ga, or Pb can also be used as the material of the electron transport layer 3d.

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

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

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

(Compound represented by the general formula (4))
As the material (electron transporting compound) of the electron transport layer 3d, a compound represented by the following general formula (4) can be preferably used.

(Ar1) n1-Y1 ... General formula (4)

  In the formula (4), n1 represents an integer of 1 or more, Y1 represents a substituent when n1 is 1, and represents a simple bond or an n1-valent linking group when n1 is 2 or more. Ar1 represents a group represented by the general formula (A) described later. When n1 is 2 or more, a plurality of Ar1s may be the same or different. However, the compound represented by the general formula (4) has at least two condensed aromatic heterocycles in which three or more rings are condensed in the molecule.

  In General formula (4), as an example of the substituent represented by Y1, it is synonymous with the substituent illustrated by General formula (1).

  In the general formula (4), specific examples of the n1-valent linking group represented by Y1 include a divalent linking group, a trivalent linking group, and a tetravalent linking group.

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

  In the general formula (4), examples of the trivalent linking group represented by Y1 include ethanetriyl, propanetriyl, butanetriyl, pentanetriyl, hexanetriyl, heptanetriyl, and octanetriyl. Group, nonanetriyl group, decanetriyl group, undecanetriyl group, dodecanetriyl group, cyclohexanetriyl group, cyclopentanetriyl group, benzenetriyl group, naphthalenetriyl group, pyridinetriyl group, carbazoletriyl group, etc. Can be mentioned.

  In the general formula (4), as the tetravalent linking group represented by Y1, one trivalent group is added to the above trivalent group, and examples thereof include a propanediylidene group and 1,3-propane. Diyl-2-ylidene group, butanediylidene group, pentanediylidene group, hexanediylidene group, heptanediylidene group, octanediylidene group, nonanediylidene group, decandiylidene group, undecandiylidene group, dodecandiylidene group, cyclohexanediylidene group , Cyclopentanediylidene group, benzenetetrayl group, naphthalenetetrayl group, pyridinetetrayl group, carbazoletetrayl group and the like.

  In addition, said bivalent coupling group, a trivalent coupling group, and a tetravalent coupling group may have the substituent further illustrated by General formula (1) respectively.

  As a preferred embodiment of the compound represented by the general formula (4), Y1 preferably represents a group derived from a condensed aromatic heterocyclic ring formed by condensation of three or more rings, and the three or more rings. As the condensed aromatic heterocyclic ring formed by condensing, a dibenzofuran ring or a dibenzothiophene ring is preferable. Further, n1 is preferably 2 or more.

  Furthermore, the compound represented by the general formula (4) has at least two condensed aromatic heterocycles obtained by condensing the above three or more rings in the molecule.

  When Y1 represents an n1-valent linking group, Y1 is preferably non-conjugated in order to keep the triplet excitation energy of the compound represented by the general formula (4) high, and further, Tg (glass transition In view of improving the point, also referred to as glass transition temperature, it is preferably composed of an aromatic ring (aromatic hydrocarbon ring + aromatic heterocycle).

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

[Group represented by general formula (A)]
Ar1 in the general formula (4) represents a group represented by the following general formula (A).

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

  Here, in —N (R) — or —Si (R) (R ′) — represented by X in the general formula (A), and —C (R1) = represented by E1 to E8, The substituent represented by each of R, R ′ and R1 has the same meaning as the substituent exemplified in Formula (1).

  In the general formula (A), the divalent linking group represented by Y2 has the same meaning as the divalent linking group represented by Y1 in the general formula (4).

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

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

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

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

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

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

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

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

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

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

  In —N (R) — or —Si (R) (R ′) — represented by X in any of the groups represented by formulas (A-1) to (A-4), E1 to E8 In —C (R1) ═ represented by the general formula (1), the substituents represented by R, R ′, and R1 have the same meanings as the substituents exemplified in the general formula (1).

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

  E11 to E20 of the general formula (A-1), E21 to E30 of the general formula (A-2), E31 to E40 of the general formula (A-3), E41 to E50 of the general formula (A-4), respectively. The substituent represented by R2 in —C (R2) ═ is synonymous with the substituent exemplified in Formula (1).

(Compound represented by the general formula (5))
Among the compounds represented by the general formula (4), compounds represented by the following general formula (5) are preferable.

  In the general formula (5), Y5 represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof. E51 to E66 each represent -C (R3) = or -N =, and R3 represents a hydrogen atom or a substituent. Y6 to Y9 each represents a group derived from an aromatic hydrocarbon ring or a group derived from an aromatic heterocycle, and at least one of Y6 or Y7 and at least one of Y8 or Y9 is an aromatic group containing an N atom. Represents a group derived from a group heterocycle. n3 and n4 represent an integer of 0 to 4, but n3 + n4 is an integer of 2 or more.

  In the general formula (5), examples of the arylene group represented by Y5 include an o-phenylene group, a p-phenylene group, a naphthalenediyl group, an anthracenediyl group, a naphthacenediyl group, a pyrenediyl group, a naphthylnaphthalenediyl group, and a biphenyldiyl group. 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 (5), examples of the heteroarylene group represented by Y5 include a carbazole ring, a carboline ring, and a diazacarbazole ring (also referred to as a monoazacarboline ring, in which one of carbon atoms constituting the carboline ring is nitrogen. The ring structure is replaced by an atom), a triazole ring, a pyrrole ring, a pyridine ring, a pyrazine ring, a quinoxaline ring, a thiophene ring, an oxadiazole ring, a dibenzofuran ring, a dibenzothiophene ring, and an indole ring. And the like.

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

  In the general formula (5), when R3 in —C (R3) ═ represented by E51 to E66 is a substituent, examples of the substituent are the same as those exemplified in the general formula (1). Applies to

  In the general formula (5), as groups represented by E51 to E66, 6 or more of E51 to E58 and 6 or more of E59 to E66 are each represented by -C (R3) =. It is preferable.

  In the general formula (5), Y6 to Y9 are each an aromatic hydrocarbon ring used for forming a group derived from an aromatic hydrocarbon ring, such as a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, and an anthracene ring. Phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring , Pentacene ring, perylene ring, pentaphen ring, picene ring, pyrene ring, pyranthrene ring, anthraanthrene ring, and the like.

  Furthermore, the aromatic hydrocarbon ring may have a substituent exemplified in the general formula (1).

  In the general formula (5), Y6 to Y9 are each an aromatic heterocycle used for forming a group derived from an aromatic heterocycle, for example, a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, or a pyridine ring. , Pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole Ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, diazacarbazole ring (one of the carbon atoms constituting the carboline ring is further substituted with a nitrogen atom) Shows the ring that is) It is below.

  Furthermore, the aromatic hydrocarbon ring may have a substituent exemplified in the general formula (1).

  In the general formula (5), an aromatic heterocycle containing an N atom used for forming a group derived from an aromatic heterocycle containing an N atom represented by at least one of Y6 or Y7 and at least one of Y8 or Y9. Examples of the ring include oxazole ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring. , Indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, diazacarbazole ring (carboline ring) Composing charcoal It shows a ring in which one atom is further substituted with a nitrogen atom), and the like.

  In the general formula (5), the groups represented by Y7 and Y9 each preferably represent a group derived from a pyridine ring.

  In general formula (5), the groups represented by Y6 and Y8 each preferably represent a group derived from a benzene ring.

(Compound represented by the general formula (6))
Among the compounds represented by the general formula (5), compounds represented by the following general formula (6) are preferable.

  In the general formula (6), 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 =, and R21 represents a hydrogen atom 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.

  Y21 in the general formula (6) has the same meaning as Y5 in the general formula (5).

  In the general formula (6), when R21 of —C (R21) = represented by E201 to E216 and E221 to E238 is a substituent, examples of the substituent are exemplified in the general formula (1). Substituents apply as well.

  In General formula (6), 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 (6), 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 (6), it is preferable that any one of E225-E229 and any one of E234-E238 represent -N =.

  Moreover, in General formula (6), it is mentioned as a preferable aspect that E221-E224 and E230-E233 are each represented by -C (R21) =.

  Further, in the compound represented by the general formula (6), 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) =.

  Specific examples of the compound represented by the general formula (4), (5), or (6) as described above include the following compounds (1 to 118).

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

  On the other hand, the electron blocking layer has the function of the hole transport layer 3b in a broad sense. The electron blocking layer is made of a material that has 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 3b mentioned later can be used as an electron blocking layer as needed. The thickness of the blocking layer according to the present invention is preferably 3 to 100 nm, and more preferably 5 to 30 nm.

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

[Encapsulant]
The sealing material covers the organic electroluminescent element EL-1 and may be a plate-shaped (film-shaped) sealing member that is fixed to the transparent substrate 13 ′ side by an adhesive. A sealing film may be used. This sealing material is provided in a state of covering at least the light emitting functional layer 3 in a state in which the terminal portions of the transparent electrode 1 and the counter electrode 5-1 in the organic electroluminescent element EL-1 are exposed. Further, an electrode may be provided on the sealing material so that the transparent electrode 1 of the organic electroluminescent element EL-1 and the terminal portions of the counter electrode 5-1 are electrically connected to this electrode.

  Specific examples of the plate-like (film-like) sealing material include a glass substrate and a polymer substrate, and these substrate materials may be used in the form of a thin film. Examples of the glass substrate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer substrate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone.

  Especially, 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 of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less measured by a method according to JIS K 7126-1987, and JIS K 7129-1992. The water vapor transmission rate (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by a method based on the above is 1 × 10 ⁻³ g / (m ² · 24 h) or less. It is preferable.

  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, not only this but a metal material may 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 electroluminescent element can be thinned.

  An adhesive for fixing such a plate-shaped sealing material to the transparent substrate 13 ′ side seals the organic electroluminescent element EL-1 sandwiched between the sealing material and the transparent substrate 13 ′. It is used as a sealing agent. Specifically, such adhesives include acrylic acid oligomers, photocuring and thermosetting adhesives having reactive vinyl groups of methacrylic acid oligomers, and moisture curable adhesives such as 2-cyanoacrylates. Mention may be made of adhesives.

  Examples of such an adhesive include epoxy-based heat and chemical curing types (two-component mixing). Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, the organic material which comprises organic electroluminescent element EL-1 may deteriorate with heat processing. For this reason, an adhesive that can be adhesively cured from room temperature to 80 ° C. is preferable. Further, a desiccant may be dispersed in the adhesive.

  Application of the adhesive to the bonding portion between the sealing material and the transparent substrate 13 ′ may be performed using a commercially available dispenser or may be printed like screen printing.

  Further, when a gap is formed between the plate-shaped sealing material, the transparent substrate 13 ′, and the adhesive, this gap may be an inert gas such as nitrogen or argon or fluorinated carbonization in the gas phase and the liquid phase. It is preferable to inject an inert liquid such as hydrogen or silicon oil. A vacuum is also possible. Moreover, a hygroscopic compound can also be enclosed inside.

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

  On the other hand, when a sealing film is used as the sealing material, the light emitting functional layer 3 in the organic electroluminescent element EL-1 is completely covered, and the terminals of the transparent electrode 1 and the counter electrode 5-1 in the organic electroluminescent element EL-1 are used. A sealing film is provided on the transparent substrate 13 ′ with the portion exposed.

  Such a sealing film is configured using an inorganic material or an organic material. In particular, it is made of a material having a function of suppressing entry of a substance that causes deterioration of the light emitting functional layer 3 in the organic electroluminescent element EL-1, such as moisture and oxygen. As such a material, for example, an inorganic material such as silicon oxide, silicon dioxide, or silicon nitride is used. Furthermore, in order to improve the brittleness of the sealing film, a laminated structure may be formed by using a film made of an organic material together with a film made of these inorganic materials.

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

[Protective film, protective plate]
Although illustration is omitted here, a protective film or a protective plate may be provided between the transparent substrate 13 ′ and the organic electroluminescent element EL and the sealing material. The protective film or the protective plate is for mechanically protecting the organic electroluminescent element EL. In particular, when the sealing material is a sealing film, mechanical protection for the organic electroluminescent element EL is prevented. Since it is not sufficient, it is preferable to provide such a protective film or protective plate.

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

[Method for Fabricating Organic Electroluminescent Device]
Here, as an example, a method of manufacturing the organic electroluminescent element EL-1 shown in FIG. 2 will be described.

  First, the high refractive index layer H is formed on the transparent substrate 13 ′ so as to have a thickness of about 30 nm. Next, the aluminum-containing layer 1a is formed to have a thickness of 10 nm or less, preferably 5 nm or less. Thereafter, an electrode layer 1b made of silver (or an alloy containing silver as a main component) is formed to a thickness of 4 nm to 12 nm, and the anode-side transparent electrode 1 is formed on the transparent substrate 13 '. The high refractive index layer H, the aluminum-containing layer 1a, and the electrode layer 1b can be formed by spin coating, casting, ink jet, vapor deposition, sputtering, printing, etc., but a uniform film can be easily obtained. The vacuum deposition method is particularly preferable from the viewpoint that pinholes are not easily generated. Further, before and after the formation of the electrode layer 1b, an auxiliary electrode pattern is formed as necessary.

Next, a hole injection layer 3a, a hole transport layer 3b, a light emitting layer 3c, an electron transport layer 3d, and an electron injection layer 3e are formed in this order on this, and the light emitting functional layer 3 is formed. The film formation of each of these layers includes spin coating, casting, ink jet, vapor deposition, sputtering, printing, etc., but it is easy to obtain a uniform film and it is difficult to generate pinholes. A vacuum deposition method or a spin coating method is particularly preferable. Further, different film forming methods may be applied for each layer. When a vapor deposition method is employed 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 ° C. to 450 ° C., and the degree of vacuum is 10 ⁻⁶ Pa to 10 ⁻⁶ . It is desirable to appropriately select each condition in the range of ⁻² Pa, vapor deposition rate of 0.01 nm / second to 50 nm / second, substrate temperature of −50 ° C. to 300 ° C., and film thickness of 0.1 μm to 5 μm.

  Next, the counter electrode 5-1 to be a cathode is formed by an appropriate film forming method such as a vapor deposition method or a sputtering method. At this time, a pattern is formed in a shape in which terminal portions are drawn from the upper side of the light emitting functional layer 3 to the periphery of the transparent substrate 13 ′ while maintaining the insulating state with respect to the transparent electrode 1 by the light emitting functional layer 3.

  Thereby, organic electroluminescent element EL-1 is obtained. Thereafter, a sealing material that covers at least the light emitting functional layer 3 is provided in a state where the terminal portions of the transparent electrode 1 and the counter electrode 5-1 in the organic electroluminescent element EL-1 are exposed. At this time, the sealing material is bonded to the transparent substrate 13 ′ using an adhesive, and the organic electroluminescent element EL- 1 is sealed between the sealing material and the transparent substrate 13 ′.

  As a result, a desired organic electroluminescent element EL-1 is obtained on the transparent substrate 13 '. In the production of such an organic electroluminescent element EL-1, it is preferable that the light emitting functional layer 3 is consistently produced from the counter electrode 5-1 by one evacuation, but in the middle of the transparent substrate 13 from the vacuum atmosphere. 'May be taken out and subjected to different film forming methods. 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 electroluminescent element EL-1 thus obtained, the anode electrode layer 1b has a positive polarity, and the cathode opposite electrode 5-1 has a negative polarity. When a voltage of about 2 V to 40 V is applied, light emission can be observed. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

<Effect of organic electroluminescent element EL-1>
The organic electroluminescent element EL-1 described above uses the transparent electrode 1 having both conductivity and light transmittance of the present invention as an anode, and a light emitting functional layer 3 and a counter electrode 5-1 serving as a cathode on the upper part. Are provided in this order. For this reason, a sufficient voltage is applied between the transparent electrode 1 and the counter electrode 5-1 to realize high-intensity light emission in the organic electroluminescent element EL-1, while the emitted light h from the transparent electrode 1 side is emitted. It is possible to increase the luminance by improving the extraction efficiency. Further, it is possible to improve the light emission life by reducing the drive voltage for obtaining a predetermined luminance.

  If the organic electroluminescent element EL-1 is a top emission type that extracts light from the counter electrode 5-1, the transparent electrode 13-1 is made of a transparent material and is reflected instead of the transparent substrate 13 '. Alternatively, a non-transparent substrate may be used, and the emitted light h may be reflected from the substrate and extracted from the counter electrode 5-1 side.

<< 4. Second example of organic electroluminescence device (top emission type) >>
<Configuration of organic electroluminescent element>
FIG. 3 is a cross-sectional configuration diagram showing a second example of the organic electroluminescent element using the transparent electrode described above as an example of the electronic device of the present invention. The organic electroluminescent element EL-2 of the second example shown in this figure is different from the organic electroluminescent element EL-1 of the first example described with reference to FIG. The light emitting functional layer 3 and the transparent electrode 1 are laminated in this order on the upper portion. Hereinafter, a detailed description of the same components as those in the first example will be omitted, and the characteristic configuration of the organic electroluminescence element EL-2 in the second example will be described.

  The organic electroluminescent element EL-2 shown in FIG. 3 is provided on the substrate 13, and the counter electrode 5-2 serving as an anode, the light emitting functional layer 3, and the transparent electrode 1 serving as a cathode are sequentially formed from the substrate 13 side. Are stacked. Of these, the transparent electrode 1 is characterized in that the transparent electrode 1 of the present invention described above is used. For this reason, the organic electroluminescent element EL-2 is configured as a top emission type that extracts the emitted light h from at least the substrate 13 side.

  The transparent electrode 1 is the transparent electrode 1 of the present invention described above, and has a configuration in which an electrode layer 1b, an aluminum-containing layer 1a, and a high refractive index layer H are sequentially formed from the light emitting functional layer 3 side. Here, in particular, the electrode layer 1b constituting the transparent electrode 1 is a substantial cathode.

  The overall layer structure of such an organic electroluminescent element EL-2 is not limited, and may be a general layer structure as in the first example. As an example of the case of the second example, the hole injection layer 3a / hole transport layer 3b / light emitting layer 3c / electron transport layer 3d / electron injection layer 3e are formed on the counter electrode 5-2 functioning as an anode. A configuration in which the transparent electrodes 1 are stacked in this order and the transparent electrode 1 serving as a cathode is stacked on the upper portion is exemplified. However, it is essential to have at least the light emitting layer 3c configured using an organic material. The electron transport layer 3d also serves as the electron injection layer 3e, and may be provided as an electron transport layer 3d having electron injection properties.

  Of such a light emitting functional layer 3, the layer serving as the base of the electrode layer 1 b constituting the transparent electrode 1, here, the electron injection layer 3 e, is configured using an organic material among the materials described in the first example. The Preferably, a nitrogen-containing compound is used. Moreover, if the layer used as the foundation | substrate of the electrode layer 1b is an electron carrying layer or the electron injection layer which served as electron transport property, it will be mentioned as a nitrogen-containing compound. The compounds represented by 4) to (6) and the compounds 1 to 118 shown as specific examples thereof are preferably used.

  In addition to these layers, the light emitting functional layer 3 adopts various configurations as necessary, as described in the first example, and a hole blocking layer and an electron not shown here are omitted. A blocking layer may be provided. In the configuration as described above, only the portion where the light emitting functional layer 3 is sandwiched between the transparent electrode 1 and the counter electrode 5-2 becomes a light emitting region in the organic electroluminescent element EL-2, as in the first example. It is.

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

Further, the counter electrode 5-2 provided as an anode below the light emitting functional layer 3 is made of a metal, an alloy, an organic or inorganic conductive compound, and a mixture thereof. Specific examples include metals such as gold (Au), oxide semiconductors such as copper iodide (CuI), ITO, ZnO, TiO ₂ , and SnO ₂ .

  The counter electrode 5-2 as described above can be produced by forming a thin film of these conductive materials by a method such as vapor deposition or sputtering. Further, the sheet resistance as the counter electrode 5-2 is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 5 nm to 5 μm, preferably 5 nm to 200 nm.

  In addition, the sealing material for sealing the top emission type organic electroluminescent element EL-2 is a transparent sealing material having light transmittance so that the emitted light h can be extracted. For such a transparent sealing material, a light-transmitting material can be used among the materials used in the first example.

  In the case where the organic electroluminescent element EL-2 takes out the emitted light h also from the counter electrode 5-2 side, the material constituting the counter electrode 5-2 is light among the conductive materials described above. A conductive material with good permeability may be selected and used. In this case, as the substrate 13, a transparent substrate having light transparency is used.

  Further, an aluminum-containing layer (not shown) may be provided between the light-emitting functional layer 3 and the electrode layer 1b with a thickness that does not hinder the electron injection property from the electrode layer 1b to the light-emitting functional layer 3. In this configuration, when an aluminum-containing layer is formed on the light emitting functional layer 3, it is preferable to form the film by an evaporation method (EB, resistance heating) or a low energy sputtering method that has little influence on the base.

<Effect of organic electroluminescent element EL-2>
The organic electroluminescent element EL-2 described above uses the transparent electrode 1 having both conductivity and light transmittance according to the present invention as a cathode, and the light emitting functional layer 3 and the anode are disposed on the electrode layer 1b side of the transparent electrode 1. The counter electrode 5-2 is provided in this order. Therefore, as in the first example, a sufficient voltage is applied between the transparent electrode 1 and the counter electrode 5-2 to realize high-luminance light emission in the organic electroluminescent element EL-2, while the transparent electrode 1 It is possible to increase the luminance by improving the extraction efficiency of the emitted light h from the side. Further, it is possible to improve the light emission life by reducing the drive voltage for obtaining a predetermined luminance.

≪5. Third example of organic electroluminescence device (double-sided light emission type) >>
<Configuration of organic electroluminescent element>
FIG. 4 is a cross-sectional configuration diagram illustrating a third example of an organic electroluminescent element using the above-described transparent electrode as an example of the electronic device of the present invention. The organic electroluminescent element EL-3 of the third example shown in this figure is different from the organic electroluminescent element EL-1 of the first example described with reference to FIG. 2 in that a transparent sealing material is used as the sealing material. The light emitting functional layer 3 is sandwiched between the two transparent electrodes 1. Hereinafter, the detailed description of the same components as those in the first example will be omitted, and the characteristic configuration of the organic electroluminescent element EL-3 in the third example will be described.

  The organic electroluminescent element EL-3 shown in FIG. 4 is provided on the transparent substrate 13 ′, and in order from the transparent substrate 13 ′ side, the transparent electrode 1 serving as the anode, the light emitting functional layer 3, and the transparent electrode serving as the cathode. 1 are stacked in this order. Of these, the transparent electrode 1 is characterized in that the transparent electrode 1 of the present invention described above is used. Accordingly, the organic electroluminescent element EL-3 is configured as a double-sided light emitting type in which the emitted light h is extracted from both the transparent substrate 13 'side and the opposite side of the transparent sealing material side.

  The overall layer structure of such an organic electroluminescent element EL-3 is not limited, but may be a general layer structure, as in the first example. As an example of the case of the third example, a hole injection layer 3a / hole transport layer 3b / light emitting layer 3c / electron transport layer 3d / electron injection layer 3e are provided in this order on the transparent electrode 1 serving as an anode. A configuration in which the transparent electrode 1 serving as a cathode is laminated on the upper portion is illustrated.

  Moreover, in the organic electroluminescent element EL-3 of the present embodiment, the transparent electrode 1 provided on the transparent substrate 13 ′ side includes the high refractive index layer H, the aluminum-containing layer 1a, and the electrode layer 1b from the transparent substrate 13 ′ side. It is provided in order. On the other hand, the transparent electrode 1 provided on the light emitting functional layer 3 is provided in the order of the electrode layer 1b, the aluminum-containing layer 1a, and the high refractive index layer H from the light emitting functional layer 3 side. Thus, the light emitting functional layer 3 is sandwiched between the electrode layer 1b substantially functioning as an anode and the electrode layer 1b substantially functioning as a cathode.

  As described in the first example, the light emitting functional layer 3 may have various configurations as necessary, and may be provided with a hole blocking layer or an electron blocking layer that is not shown here. . In the above configuration, only the portion sandwiched between the two transparent electrodes 1 becomes the light emitting region in the organic electroluminescent element EL-3, as in the first example.

  However, of the light emitting functional layer 3, the layer serving as the base of the electrode layer 1b constituting the transparent electrode 1 provided on the light emitting functional layer 3, here the electron injection layer 3e is the material described in the first example. Consists of organic materials. Preferably, a nitrogen-containing compound is used. As the nitrogen-containing compound, the compounds represented by the general formulas (4) to (6) described as the material for the electron transport layer 3d in the first example and the compounds 1 to 118 shown as specific examples thereof are preferably used.

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

  Furthermore, since this organic electroluminescent element EL-3 is a double-sided light emitting type, it is sealed with a transparent sealing material having light transmittance.

  An aluminum-containing layer (not shown) may be provided between the electron injection layer 3e and the electrode layer 1b with a thickness that does not hinder the electron injection property from the electrode layer 1b to the light emitting functional layer 3. In this configuration, when an aluminum-containing layer is formed on the electron injection layer 3e, it is preferable to form the film by an evaporation method (EB, resistance heating) or a low energy sputtering method that has little influence on the base.

<Effect of organic electroluminescent element EL-3>
The organic electroluminescent element EL-3 described above has a configuration in which the transparent electrode 1 having both conductivity and light transmittance of the present invention is used as an anode and a cathode, and the light emitting functional layer 3 is sandwiched therebetween. For this reason, as in the first example, a sufficient voltage is applied between the two transparent electrodes 1 to realize high-intensity light emission in the organic electroluminescent element EL-3, and light emission from the two transparent electrodes 1 side. It is possible to increase the brightness by improving the extraction efficiency of the light h. Further, it is possible to improve the light emission life by reducing the drive voltage for obtaining a predetermined luminance.

≪6. Fourth example of organic electroluminescence device (reverse stacking configuration) >>
<Configuration of organic electroluminescent element>
FIG. 5 is a cross-sectional configuration diagram showing a fourth example of an organic electroluminescent element using the above-described transparent electrode as an example of the electronic device of the present invention. The organic electroluminescent element EL-4 of the fourth example shown in this figure is different from the organic electroluminescent element EL-1 of the first example described with reference to FIG. The electrode 1), the light emitting functional layer 3, and the anode (counter electrode 5-4) are provided and the stacking order is reversed. Hereinafter, a detailed description of the same components as those in the first example will be omitted, and a characteristic configuration of the organic electroluminescence element EL-4 in the fourth example will be described.

  The organic electroluminescent element EL-4 shown in FIG. 5 is provided on the transparent substrate 13 ′, and in order from the transparent substrate 13 ′ side, the transparent electrode 1 serving as the cathode, the light emitting functional layer 3, and the counter electrode serving as the anode. 5-4 are laminated in this order. Of these, the transparent electrode 1 is characterized in that the transparent electrode 1 of the present invention described above is used. For this reason, the organic electroluminescent element EL-4 is configured as a bottom emission type in which the emitted light h is extracted from at least the transparent substrate 13 'side.

  The overall layer structure of such an organic electroluminescent element EL-4 is not limited, and may be a general layer structure as in the first example. As an example of the case of the fourth example, an electron injection layer 3e / electron transport layer 3d / light emitting layer 3c / hole transport layer 3b / hole injection layer 3a are provided in this order on the transparent electrode 1 serving as a cathode. A configuration in which a counter electrode 5-4 serving as an anode is laminated on the upper portion is illustrated.

  As described in the first example, the light emitting functional layer 3 may have various configurations as necessary, and may be provided with a hole blocking layer or an electron blocking layer that is not shown here. . In the configuration as described above, only the portion sandwiched between the transparent electrode 1 and the counter electrode 5-4 becomes a light emitting region in the organic electroluminescent element EL-4, as in the first example.

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

  Further, the counter electrode 5-4 provided as the anode above the light emitting functional layer 3 is made of the same metal, alloy, organic or inorganic conductive compound as the anode of the first example, and a mixture thereof.

<Effect of organic electroluminescent element EL-4>
The organic electroluminescent element EL-4 described above uses the transparent electrode 1 having both conductivity and light transmittance according to the present invention as a cathode, and a light emitting functional layer 3 and a counter electrode 5-4 serving as an anode on the upper side. Are provided in this order. Therefore, as in the first example, a sufficient voltage is applied between the transparent electrode 1 and the counter electrode 5-4 to realize high luminance light emission in the organic electroluminescent element EL-4, while the transparent electrode 1 It is possible to increase the luminance by improving the extraction efficiency of the emitted light h from the side. Further, it is possible to improve the light emission life by reducing the drive voltage for obtaining a predetermined luminance.

≪7. Applications of organic electroluminescent devices >>
Since the organic electroluminescent elements having the above-described configurations are surface light emitters as described above, they can be used as various light emission sources. For example, lighting devices such as home lighting and interior lighting, backlights for clocks and liquid crystals, lighting for billboard advertisements, light sources for traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, Examples include, but are not limited to, a light source of an optical sensor, and can be effectively used as a backlight of a liquid crystal display device combined with a color filter and a light source for illumination.

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

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

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

≪8. Lighting device-1 >>
The illuminating device of this invention has the said organic electroluminescent element.

  The organic electroluminescent element used in the lighting device of the present invention may be designed such that each organic electroluminescent element having the above-described configuration has a resonator structure. Examples of the purpose of use of the organic electroluminescence device configured as a resonator structure include, but are not limited to, a light source of an optical storage medium, a light source of an electrophotographic copying machine, a light source of an optical communication processor, a light source of an optical sensor, and the like. Not. Moreover, you may use for the said use by making a laser oscillation.

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

  In addition, the combination of luminescent materials for obtaining multiple luminescent colors is a combination of multiple phosphorescent or fluorescent materials that emit light, fluorescent materials or phosphorescent materials, and light from the luminescent materials. Any combination with a dye material that emits light as light may be used, but in a white organic electroluminescent element, a combination of a plurality of light-emitting dopants may be used.

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

  Further, the light emitting material used for the light emitting layer of such a white organic electroluminescent element is not particularly limited. For example, a backlight in a liquid crystal display element is adapted to a wavelength range corresponding to the CF (color filter) characteristics. In addition, any metal complex according to the present invention or a known light emitting material may be selected and combined to be whitened.

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

≪9. Lighting device-2 >>
Moreover, the organic electroluminescent element of this invention can be used also as an illuminating device which used multiple and made the light emission surface large area. In this case, the light emitting surface is enlarged by arranging a plurality of light emitting panels provided with organic electroluminescent elements on a transparent substrate on the support substrate (that is, tiling). The support substrate may also serve as a sealing material, and each light emitting panel is tiled in a state where the organic electroluminescent element is sandwiched between the support substrate and the transparent substrate of the light emitting panel. An adhesive may be filled between the support substrate and the transparent substrate, thereby sealing the organic electroluminescent element. Note that the terminals of the transparent electrode and the counter electrode are exposed around the light emitting panel.

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

≪Preparation of transparent electrode≫
The transparent electrodes of Samples 101 to 118 were prepared so that the area of the conductive region was 5 cm × 5 cm. Table 1 below shows the configuration of each layer in each of the transparent electrodes of Samples 101 to 118.

<Preparation of Transparent Electrodes of Samples 101 to 103>
As described below, an electrode layer made of silver was formed on a glass substrate with each film thickness shown in Table 1 below.

First, a transparent alkali-free glass substrate was fixed to a substrate holder of a commercially available vacuum deposition apparatus and attached to a vacuum tank of the vacuum deposition apparatus. Moreover, silver (Ag) was put into the resistance heating boat made from tungsten, and it attached in the said vacuum chamber. Next, after depressurizing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the resistance heating boat was energized and heated, and the electrode layers made of silver were respectively deposited at a deposition rate of 0.1 nm / second to 0.2 nm / second. It was formed with a film thickness. Sample 101 was formed with a film thickness of 6 nm, sample 102 was formed with a film thickness of 8 nm, and sample 103 was formed with a film thickness of 15 nm.

<Preparation of transparent electrodes of samples 104 to 106>
In the following manner, a high refractive index layer made of titanium dioxide (TiO ₂ ) is formed on a glass substrate with a film thickness of 30 nm, and an electrode layer made of silver is shown in Table 1 below. The film thickness was formed.

First, a transparent alkali-free glass base material is fixed to a base material holder of a commercially available vacuum deposition apparatus, titanium dioxide (TiO ₂ ) is placed in a heating boat, and these substrate holder and heating boat are connected to the vacuum deposition apparatus. Attached to the first vacuum chamber. Moreover, silver (Ag) was put into the resistance heating boat made from tungsten, and it attached to the 2nd vacuum chamber of the vacuum evaporation system.

Next, after reducing the pressure in the first vacuum tank of the vacuum deposition apparatus to 4 × 10 ⁻⁴ Pa, the heating boat containing titanium dioxide (TiO ₂ ) was irradiated with an electron beam and heated, and the deposition rate was 0.1 nm / second. A high refractive index layer made of titanium dioxide having a film thickness of 30 nm was provided on the substrate at a rate of ˜0.2 nm / second.

Next, the base material formed up to the high refractive index layer is transferred to the second vacuum chamber while being vacuumed, and the vacuum chamber is depressurized to 4 × 10 ⁻⁴ Pa, and then a resistance heating boat containing silver is energized. Heated. Thereby, electrode layers made of silver were formed in respective film thicknesses at a deposition rate of 0.1 nm / second to 0.2 nm / second. The sample 104 was formed with a film thickness of 6 nm, the sample 105 was formed with a film thickness of 8 nm, and the sample 106 was formed with a film thickness of 15 nm.

<Preparation of Transparent Electrodes of Samples 107 to 110>
In the following manner, a high refractive index layer made of titanium dioxide (TiO ₂ ) is formed with a film thickness of 30 nm on a glass substrate, and an aluminum-containing layer made of aluminum is shown in Table 1 below. Each film thickness was formed, and an electrode layer made of silver was formed thereon with a film thickness of 8 nm.

First, a transparent alkali-free glass base material is fixed to a base material holder of a commercially available vacuum deposition apparatus, titanium dioxide (TiO ₂ ) is placed in a heating boat, and these substrate holder and heating boat are connected to the vacuum deposition apparatus. Attached to the first vacuum chamber. Next, aluminum (Al) was put into a resistance heating boat made of tungsten and attached to the second vacuum chamber of the vacuum evaporation apparatus. Moreover, silver (Ag) was put into the resistance heating boat made from tungsten, and it attached to the 3rd vacuum chamber of a vacuum evaporation system.

Next, after reducing the pressure in the first vacuum chamber of the vacuum deposition apparatus to 4 × 10 ⁻⁴ Pa, the heating boat containing titanium dioxide was irradiated with an electron beam and heated to deposit a deposition rate of 0.1 nm / second to 0.2 nm. A high refractive index layer made of titanium dioxide having a thickness of 30 nm was provided on the substrate at a rate of / sec.

Subsequently, the base material formed up to the high refractive index layer is transferred to the second vacuum chamber while being vacuumed, and after the pressure of the second vacuum chamber is reduced to 4 × 10 ⁻⁴ Pa, the resistance heating boat containing aluminum is energized. And heated. Thereby, the aluminum containing layer which consists of aluminum was provided in each film thickness on the high refractive index layer with the vapor deposition rate of 0.1 nm / sec-0.2 nm / sec. Sample 107 was formed with a thickness of 0.1 nm, Sample 108 was formed with a thickness of 1 nm, Sample 109 was formed with a thickness of 5 nm, and Sample 110 was formed with a thickness of 10 nm.

Next, the base material formed up to the aluminum-containing layer was transferred to the third vacuum chamber, and after the pressure in the third vacuum chamber was reduced to 4 × 10 ⁻⁴ Pa, the resistance heating boat containing silver was energized and heated. Thus, an electrode layer made of silver having a film thickness of 8 nm was formed at a deposition rate of 0.1 nm / second to 0.2 nm / second.

<Preparation of Transparent Electrodes of Samples 111 to 113>
Transparent electrodes of Samples 111 to 113 were obtained in the same procedure as Sample 108, except that the materials used for the aluminum-containing layer were the compounds shown in Table 1 below. Note that a TiAl alloy (composition ratio Ti: Al = 1: 1) was used for the aluminum-containing layer of the sample 111.

<Preparation of transparent electrode of sample 114>
A transparent electrode of Sample 114 was obtained in the same procedure as Sample 108, except that polyethylene terephthalate (PET) was used as the substrate.

<Preparation of Transparent Electrodes of Samples 115 to 117>
Transparent electrodes of Samples 115 to 117 were obtained in the same procedure as Sample 108, except that the materials used for the high refractive index layer were the compounds shown in Table 1 below.

<Preparation of Transparent Electrode of Sample 118>
As described below, an aluminum-containing layer made of aluminum was formed with a thickness of 1 nm on a glass substrate, and an electrode layer made of silver was formed thereon with a thickness of 8 nm.

  First, a transparent non-alkali glass base material is fixed to a base material holder of a commercially available vacuum deposition apparatus, aluminum (Al) is placed in a resistance heating boat made of tungsten, and these substrate holders and the heating boat are vacuum-deposited. Attached to the first vacuum chamber of the apparatus. Next, silver (Ag) was put into a resistance heating boat made of tungsten and attached to the second vacuum chamber of the vacuum evaporation apparatus.

Subsequently, the first vacuum tank of the vacuum evaporation apparatus was depressurized to 4 × 10 ⁻⁴ Pa, and then a resistance heating boat containing aluminum was energized and heated. This provided the aluminum containing layer which consists of aluminum with a film thickness of 1 nm on the base material with the vapor deposition rate of 0.1 nm / second to 0.2 nm / second.

Next, the base material formed up to the aluminum-containing layer was transferred to the second vacuum chamber, and after the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa, the resistance heating boat containing silver was energized and heated. Thus, an electrode layer made of silver having a film thickness of 8 nm was formed at a deposition rate of 0.1 nm / second to 0.2 nm / second.

<Evaluation of each sample of Example 1>
About each transparent electrode of the samples 101-118 produced above, the light transmittance and sheet resistance value were measured. The light transmittance was measured using a spectrophotometer (U-3300, manufactured by Hitachi, Ltd.), using the same substrate as the sample as the baseline. The sheet resistance value was measured using a resistivity meter (MCP-T610 manufactured by Mitsubishi Chemical Corporation) by a 4-terminal 4-probe method constant current application method. The results are shown in Table 1 below.

<Evaluation result of Example 1>
As is clear from Table 1, the transparent electrodes of Samples 107 to 117 in which three layers of a high refractive index layer, an aluminum-containing layer, and an electrode layer are laminated in this order are electrodes using silver that carries substantial conductivity. Although the layer is an ultra-thin film of 8 nm, the sheet resistance value can be measured, and the layer is formed with a substantially uniform film thickness by single-layer growth type (Frank-van der Merwe: FM type) film growth. Was confirmed.

  Moreover, it was confirmed that the transparent electrodes of Samples 107 to 117 having these aluminum-containing layers have a light transmittance of 50% or more and can be used as transparent electrodes. This result was the same whether the substrate was glass or plastic material (PET). Furthermore, the same result was obtained even when the material used for the aluminum-containing layer was aluminum, an aluminum alloy, aluminum oxide, or aluminum nitride. Furthermore, similar results were obtained even when the material used for the high refractive index layer was niobium oxide, tantalum oxide, or cerium oxide.

  On the other hand, the transparent electrodes of the samples 101 and 102 having a single-layer structure with only the electrode layer and the samples 104 and 105 having a structure in which the electrode layer is laminated on the high refractive index layer without providing the aluminum-containing layer have a sheet resistance. Measurement was impossible, and it could not be used as an electrode. In Samples 103 and 106, the film thickness of the electrode layer was 15 nm, so that the sheet transmittance was low but the light transmittance was low, so that it could not be used as a transparent electrode.

  The transparent electrodes of Samples 107 to 110 differed only in the thickness of the aluminum-containing layer. The thicker the aluminum-containing layer, the lower the sheet resistance value. This is considered to be because the film quality of silver constituting the electrode layer on the aluminum-containing layer is improved. Of these, the transparent electrodes of Samples 107 to 109, in which the film thickness of the aluminum-containing layer was 5 nm or less, had a favorable light transmittance of 80% or more. Thereby, it was confirmed that the film thickness of the aluminum-containing layer is preferably 5 nm or less.

  The transparent electrodes of Samples 108 and 111 to 113 differ only in the material used for the aluminum-containing layer. When these are compared, the transparent electrode of Sample 112 using aluminum oxide has a light transmittance of less than 80%. The sheet resistance value was 10Ω / □ or more. This includes aluminum atoms that are stably bonded to silver atoms, and oxygen atoms that are difficult to bond to silver atoms, so that some of the silver aggregates, thereby reducing the film quality of the silver that constitutes the electrode layer. The result is considered.

  Moreover, the transparent electrode of the sample 118 is a transparent electrode in which two layers of an aluminum-containing layer and an electrode layer are laminated in this order, and the electrode layer using silver responsible for substantial conductivity is an extremely thin film of 8 nm. In addition, it was possible to measure the sheet resistance value, and it was confirmed that the film was formed with a substantially uniform film thickness by single-layer growth type (Frank-van der Merwe: FM type) film growth. Further, it was confirmed that the transparent electrode of the sample 118 has a light transmittance of 50% or more and can be used as a transparent electrode.

  The transparent electrode of the sample 108 having the three-layer structure in which the high refractive index layer is added to the transparent electrode of the sample 118 having the two-layer structure is different only in the presence or absence of the high refractive index layer. When these were compared, it was confirmed that the transparent electrode of the sample 108 having a high refractive index layer had a better light transmittance.

≪Fabrication of bottom emission type organic electroluminescence element≫
A bottom emission type organic electroluminescence device was produced in which each transparent electrode having the configuration produced in Example 1 was provided as an anode under the light emitting functional layer. The manufacturing procedure will be described with reference to FIG. In addition, in the following Table 2, the structure of the transparent electrode used for the organic electroluminescent element of samples 201-218 was shown. For each organic electroluminescent element, each transparent electrode of Example 1 in which the last two digits of the sample number coincide was used.

<Procedure for producing organic electroluminescent elements of Samples 201 to 218>
(Formation of transparent electrode 1)
First, in preparation of the samples 201-218, each transparent electrode 1 was formed on the transparent transparent substrate 13 'made of transparent alkali-free glass. Each transparent electrode 1 was formed in the same procedure as the samples 101 to 118 in Example 1. However, in the production of the sample 214, a transparent substrate 13 ′ of polyethylene terephthalate (PET) was used.

(Formation of hole transport / injection layer 31)
First, as a hole transport injection material, a heating boat containing α-NPD represented by the following structural formula is energized and heated, and the hole transport / hole transport layer that serves as both the hole injection layer and the hole transport layer made of α-NPD An injection layer 31 was formed on the transparent electrode 1. At this time, the deposition rate was 0.1 nm / second to 0.2 nm / second, and the film thickness was 20 nm.

(Formation of the light emitting layer 32)
Next, each of the heating boat containing the host compound H4 having the structural formula shown above and the heating boat containing the phosphorescent compound Ir-4 having the structural formula shown above were energized independently to each other. A light emitting layer 32 made of H4 and phosphorescent compound Ir-4 was formed on the hole transport / injection layer 31. At this time, the energization of the heating boat was adjusted so that the deposition rate was the host material H4: phosphorescent compound Ir-4 = 100: 6. The film thickness was 30 nm.

(Formation of hole blocking layer 33)
Next, a heating boat containing BAlq represented by the following structural formula as a hole blocking material was energized and heated to form a hole blocking layer 33 made of BAlq on the light emitting layer 32. At this time, the deposition rate was 0.1 nm / second to 0.2 nm / second, and the film thickness was 10 nm.

(Formation of electron transport / injection layer 34)
Thereafter, a heating boat containing the compound 10 having the structural formula shown above as an electron transporting material and a heating boat containing potassium fluoride were energized independently to inject electrons consisting of the compound 10 and potassium fluoride. An electron transport / injection layer 34 serving as both a layer and an electron transport layer was formed on the hole blocking layer 33. At this time, the energization of the heating boat was adjusted so that the deposition rate was compound 10: potassium fluoride = 75: 25. The film thickness was 30 nm.

(Counter electrode 5-1: formation of cathode)
After the above, the transparent substrate 13 ′ on which the light emitting functional layer 3 is formed is transferred into the second vacuum chamber of the vacuum deposition apparatus, and after the pressure in the second vacuum chamber is reduced to 4 × 10 ⁻⁴ Pa, 2 The heating board containing aluminum attached in the vacuum chamber was energized and heated. Thus, a counter electrode 5-1 made of aluminum having a film thickness of 100 nm was formed at a deposition rate of 0.3 nm / second. The counter electrode 5-1 is used as a cathode. Thus, a bottom emission type organic electroluminescent element EL-1 was formed on the transparent substrate 13 ′.

(Element sealing)
Thereafter, the organic electroluminescent element EL-1 is covered with a sealing material made of a glass substrate having a thickness of 300 μm, and the organic electroluminescent element EL-1 is surrounded between the transparent sealing material and the transparent substrate 13 ′. Adhesive (sealant) was filled. As the adhesive, an epoxy photocurable adhesive (Luxtrac LC0629B manufactured by Toagosei Co., Ltd.) was used. The adhesive filled between the transparent encapsulant and the transparent substrate 13 ′ is irradiated with UV light from the glass substrate (transparent encapsulant) side to cure the adhesive, and the organic electroluminescent element EL-1 Was sealed.

  In forming the organic electroluminescent element EL-1, a vapor deposition mask is used for forming each layer, and the central 4.5 cm × 4.5 cm of the 5 cm × 5 cm transparent substrate 13 ′ is used as the light emitting region. A non-light emitting region having a width of 0.25 cm was provided on the entire circumference. The electrode layer 1b of the transparent electrode 1 serving as the anode and the counter electrode 5-1 serving as the cathode are insulated by the hole transport / injection layer 31 to the electron transport / injection layer 34, and the transparent substrate 13 ′. The terminal part was formed in the shape pulled out to the periphery of the.

  As described above, each light emitting panel of the organic electroluminescent elements of Samples 201 to 218 in which the organic electroluminescent element EL-1 is provided on the transparent substrate 13 ′ and this is sealed with the transparent sealing material and the adhesive. Obtained. In each of these light emitting panels, each color of emitted light h generated in the light emitting layer 32 is extracted from the transparent substrate 13 'side.

<Evaluation of each sample of Example 2>
About the organic electroluminescent element EL-1 (light emission panel) produced with the samples 201-218, the drive voltage and the chromaticity difference were measured. The results are also shown in Table 2 below.

In the measurement of the driving voltage, the voltage when the front luminance on the transparent electrode 1 side (that is, the transparent substrate 13 ′ side) of each organic electroluminescent element EL-1 was 1000 cd / m ² was measured as the driving voltage. A spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used for measuring the luminance. A smaller value of the obtained drive voltage indicates a more favorable result.

In the measurement of the chromaticity difference, a current of ^2.5 mA / cm ² was applied to each organic electroluminescent element EL-1, and the chromaticity in the CIE 1931 color system was measured from a position at a different angle. At this time, the chromaticity was measured at a position of 0 ° which is a normal direction to the light emitting surface on the transparent electrode 1 side and each position of 45 ° in the vertical horizontal (up, down, left and right) directions. The differences in chromaticity measured at different angles are shown in Table 2 below as chromaticity differences. The chromaticity difference represents the viewing angle characteristic of chromaticity, and the smaller the numerical value, the better the result.

<Evaluation results of Example 2>
As is apparent from Table 2, it was confirmed that the organic electroluminescent elements of Samples 207 to 218 having an aluminum-containing layer can emit light with a front luminance of 1000 cd / m ² at a low driving voltage of 7 V or less. Further, it was confirmed that these organic electroluminescent elements were suppressed to have a chromaticity difference of 0.09 or less depending on the viewing angle.

  On the other hand, the organic electroluminescent elements of the samples 201 and 202 having a single-layer structure with only the electrode layer and the samples 204 and 205 having a structure in which the electrode layer is stacked on the high refractive index layer without providing the aluminum-containing layer are as follows: It was confirmed that no luminescence was obtained. Further, it was confirmed that the organic electroluminescent elements of Samples 203 and 206 can emit light with a low driving voltage of 5 V or less because the electrode layer has a film thickness of 15 nm and functions as an electrode. However, it was confirmed that the electrode layer made of thick silver having a low light transmittance has a large chromaticity difference depending on the viewing angle.

  From the above, it was confirmed that the organic electroluminescent element using the transparent electrode having the configuration of the present invention is capable of high luminance emission at a low driving voltage and stable surface emission. In addition, it was confirmed that the driving voltage for obtaining the predetermined luminance can be reduced and the light emission life can be improved.

  DESCRIPTION OF SYMBOLS 1 ... Transparent electrode, 1a ... Aluminum containing layer, 1b ... Electrode layer, H ... High refractive index layer, EL-1, EL-2 ... Organic electroluminescent element (electronic device)

Claims (7)

An aluminum-containing layer having a thickness of 10 nm or less;
Provided in contact with a functional layer constituting an electronic device, an electrode layer mainly composed of silver provided on the aluminum-containing layer adjacent to the aluminum-containing layer,
A high refractive index having a refractive index of 2.0 or more at a wavelength of 550 nm composed of a metal oxide, sandwiching the aluminum-containing layer between the electrode layers and in contact with the aluminum-containing layer A transparent electrode comprising a layer. The transparent electrode according to claim 1, wherein the high refractive index layer is made of titanium dioxide (TiO ₂ ). The transparent electrode according to claim 1, wherein the aluminum-containing layer has a thickness of 5 nm or less. The transparent electrode according to any one of claims 1 to 3,
An electronic device having a functional layer provided in contact with the electrode layer. The electronic device according to claim 4, wherein the electronic device is an organic electroluminescent element. The transparent electrode, a counter electrode disposed to face the transparent electrode, and a light emitting functional layer including at least a light emitting layer disposed between the transparent electrode and the counter electrode,
The distance between the interface between the transparent electrode and the light emitting functional layer and the interface between the counter electrode and the light emitting functional layer is a minute that enhances the light intensity of a specific wavelength among the light emitted from the light emitting layer. Does not constitute a resonator
The electronic device according to claim 4 or 5. The transparent electrode, a counter electrode disposed to face the transparent electrode, a light emitting functional layer including at least a light emitting layer disposed between the transparent electrode and the counter electrode, and a substrate,
From one main surface side of the substrate, the counter electrode, the light emitting functional layer, and the transparent electrode are provided in this order,
  In the transparent electrode, the electrode layer, the aluminum-containing layer, and the high refractive index layer are provided in this order from the light emitting functional layer side.
Light emitted from the light emitting layer is emitted from the transparent electrode side.
The electronic device of any one of Claims 4-6.