JP6330543B2 - 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 further to an electronic device using the transparent electrode.

  In recent years, low-resistance transparent electrodes have been demanded as electrodes for various electronic devices such as liquid crystal displays, plasma displays, display devices such as inorganic and organic electroluminescence displays, touch panels, and solar cells.

  In addition, organic electroluminescent elements (so-called organic EL) using electroluminescence (hereinafter referred to as EL) of organic materials as surface light emitters such as backlights of various displays, display boards such as signboards and emergency lights, and illumination light sources. Device) has attracted attention. An organic EL element is a thin-film type completely solid element that can emit light at a low voltage of about several volts to several tens of volts, and has many excellent features such as high brightness, high luminous efficiency, thinness, and light weight.

  Such an organic EL 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 required to be a transparent electrode having low resistance and high light transmittance.

Here, the transparent electrode, having high light transmittance of indium tin oxide is _{(SnO 2 -In 2 O 3:} : Indium Tin Oxide ITO) oxide semiconductor-based material such as is commonly used, ITO Studies have been made aiming at lowering resistance by laminating silver and silver (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 lower the resistance, and there is a limit to further low resistance.

  In general, when a transparent electrode is made of a metal material such as silver having a high electrical conductivity, a metal film growth in a vacuum usually takes a Volmer-Weber growth mode. , The nuclei grow and the nuclei coalesce to form a continuous film. For this reason, when the film thickness of the transparent electrode is made thin, the film tends to be isolated like islands, and when it is grown to a continuous film, the film thickness becomes thick, and the conductivity and light transmittance The trade-off cannot be resolved.

  Therefore, by providing an electrode layer using silver or an alloy containing silver as a main component adjacent to the nitrogen-containing layer, a transparent electrode having low resistance while maintaining light transmittance, and an organic EL using the transparent electrode An element has been proposed (see, for example, Patent Document 3 below).

JP 2002-15623 A Japanese Unexamined Patent Publication No. 2006-164961 International Publication No. 2013/073356

However, even in such a transparent electrode, it cannot be said that both conductivity and light transmittance are sufficient.
Therefore, in the transparent electrode, further compatibility between electrical conductivity and light transmittance is required.

  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.

In order to achieve such an object, the transparent electrode of the present invention is in contact with a transparent substrate, a conductive layer mainly composed of silver, and the conductive layer between the transparent substrate and the conductive layer. A calcium layer made of metallic calcium (Ca) provided, the film thickness ratio of the conductive layer to the calcium layer is in the range of 10: 1 to 30: 1 , and the conductive layer is closest to the transparent substrate It constitutes an electrode.

  The electronic device of the present invention is characterized by having the transparent electrode having the above-described configuration. The electronic device is, for example, an organic electroluminescent element.

  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 to improve the 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 (3 layer structure) which concerns on the 1st Embodiment of this invention. It is a cross-sectional schematic diagram which shows the structure of the transparent electrode (4 layer structure) which concerns on the 2nd Embodiment of this invention. It is a cross-sectional schematic diagram which shows the structure of the transparent electrode (5 layer structure) which concerns on the 3rd Embodiment of this invention. It is a section lineblock diagram showing an example of an electronic device (organic EL element) using a transparent electrode of the present invention. 2 is an SEM image of a transparent electrode of a sample 101 produced in Example 1. 2 is a SEM image of a transparent electrode of a sample 111 produced in Example 1. 2 is an SEM image of a transparent electrode of a sample 112 produced in Example 1. 2 is a SEM image of a transparent electrode 124 'produced in Example 1. 2 is an SEM image of a transparent electrode of a sample 124 produced in Example 1. 2 is a SEM image of a transparent electrode of a sample 124 ″ produced in Example 1. 2 is an SEM image of a transparent electrode after high-temperature storage of a sample 124 ′ produced in Example 1. It is the SEM image of the transparent electrode after the high temperature preservation | save of the sample 124 produced in Example 1 (the 1). It is the SEM image of the transparent electrode after the high temperature preservation | save of the sample 124 produced in Example 1 (the 2). 2 is a SEM image of a transparent electrode after high-temperature storage of a sample 124 ″ produced in Example 1. 4 is a cross-sectional configuration diagram illustrating a bottom emission type organic EL element manufactured in Example 2. FIG.

Hereinafter, embodiments of the present invention will be described in the following order based on the drawings.
1. 1. First embodiment: transparent electrode having a three-layer structure 2. Second embodiment: a transparent electrode having a four-layer structure provided with a base layer 3. Third embodiment: a transparent electrode having a five-layer structure provided with an optical adjustment layer 4. Fourth embodiment: Use of transparent electrode Fifth embodiment: electronic device (organic EL element)
6). Sixth Embodiment: Applications of electronic devices (organic EL elements)

<< 1. First Embodiment: Transparent Electrode with Three-Layer Structure >>
FIG. 1 is a schematic cross-sectional view showing the configuration of the transparent electrode (three-layer structure) according to the first embodiment of the present invention. As shown in this figure, the transparent electrode 10 has a three-layer structure in which a transparent substrate 11, a calcium-containing layer 1, and a conductive layer 2 mainly composed of silver are laminated. That is, for example, the calcium-containing layer 1 and the conductive layer 2 are provided in this order on the transparent substrate 11. Among these, the electroconductive layer 2 which comprises the electrode part in the transparent electrode 10 is a layer comprised mainly by silver (Ag). Further, the calcium-containing layer 1 adjacent to the conductive layer 2 is characterized by containing calcium (Ca) for improving the film quality of the conductive layer 2.

  Below, the detail of each component which comprises the transparent electrode 10 of such a laminated structure is demonstrated in order of the transparent substrate 11, the calcium containing layer 1, and the electroconductive layer 2. FIG. In addition, the transparency of the transparent electrode 10 of the present invention means that the light transmittance at a wavelength of 550 nm is 50% or more.

<Transparent substrate>
Examples of the transparent substrate 11 include, but are not limited to, 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 viewpoint of adhesion, durability, and smoothness with the calcium-containing layer 1, the surface of these glass materials is subjected to physical treatment such as polishing, or a coating made of an inorganic or 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 (TAC), cellulose acetate butyrate, cellulose acetate propionate ( CAP), cellulose esters such as cellulose acetate phthalate, cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Is mentioned.

On the surface of the resin film, a film made of an inorganic material or an organic material or a hybrid film combining these films may be formed. Such coatings and hybrid coatings have a water vapor transmission rate (25 ± 0.5 ° C., relative humidity 90 ± 2% RH) 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 a material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, etc. Can be used. Furthermore, in order to improve the brittleness of the 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.

<Calcium-containing layer>
The calcium-containing layer 1 is configured to contain calcium (Ca) and is provided between the transparent substrate 11 and the conductive layer 2 so as to be in contact with the conductive layer 2. Such a calcium-containing layer 1 is a layer for improving the film quality of the conductive layer 2 as shown in Examples described later, and has a thickness of 2.0 nm or less. It is characteristic that the two bases are arranged adjacent to each other.

  It is important that the calcium-containing layer 1 as described above has such a thickness that the interaction with the conductive layer 2 can be obtained without inhibiting the light transmittance of the transparent electrode 10. For this reason, the calcium-containing layer 1 may be an island-like film having, for example, one or more atomic layers of calcium (Ca) on the transparent substrate 11, or a film having a plurality of holes. Alternatively, it may be a continuous film.

  The calcium-containing layer 1 is not particularly limited as long as it contains calcium (Ca), and may be formed of a single material of calcium (Ca) or may be a mixed material with other compounds. For example, the calcium-containing layer 1 may include not only calcium (Ca) but also calcium oxide (CaO) partially or entirely. Further, for example, the calcium-containing layer 1 may further include a metal material such as silver (Ag) that constitutes the conductive layer 2.

  The calcium-containing layer 1 is preferably a layer composed mainly of calcium (Ca) from the viewpoint of stabilizing the film quality of the conductive layer 2. The main component as used in the field of this invention means that the mass ratio of the calcium (Ca) with respect to the total mass of the calcium content layer 1 is 50 mass% or more, Preferably it is 70 mass% or more.

  The film thickness of the calcium-containing layer 1 is preferably in the range of 2.0 nm or less, and more preferably in the range of 0.5 to 2.0 nm. In addition, the film thickness here is an average thickness. Moreover, this film thickness shall be the film thickness adjusted with the formation speed and formation time of the calcium content layer 1, for example.

By setting the film thickness of the calcium-containing layer 1 to 0.5 nm or more, the transparent electrode 10 has a reduced surface resistance and improved transmittance as shown in Examples described later. Moreover, sufficient interaction with the silver atom which comprises the electroconductive layer 2 can be acquired, without inhibiting the optical characteristic of the transparent electrode 10 by the film thickness of the calcium containing layer 1 being 2.0 nm or less. .
Thereby, the conductive layer 2 on the calcium-containing layer 1 can be formed to have a stable film quality with a uniform thickness even though it is thin.

  That is, as shown in an SEM image of an example described later, the film formation state of the conductive layer 2 on the calcium-containing layer 1 becomes favorable. Further, even in a SEM image after storage at a high temperature, the conductive layer 2 having a stable film quality can be formed with a uniform thickness even though it is thin without spreading minute defects at the time of film formation.

  In addition, the method for forming the calcium-containing layer 1 is not particularly limited, but a dry process such as a vapor deposition method (resistance heating, EB method, etc.) is preferably applied from the viewpoint of stabilizing the film quality.

<Conductive layer>
The conductive layer 2 is a layer composed mainly of silver, is composed of silver or an alloy composed mainly of silver, and is formed on one main surface of the transparent substrate 11 via the calcium-containing layer 1. It is a layer provided.

  The conductive layer 2 is preferably a layer composed mainly of silver or silver (Ag) from the viewpoint of low intrinsic absorption and high electrical conductivity. The alloy mainly composed of silver (Ag) constituting the conductive layer 2 is preferably an alloy containing 50% by mass or more of silver. Examples of the alloy mainly composed of silver (Ag) include silver magnesium (AgMg), silver copper (AgCu), silver palladium (AgPd), silver palladium copper (AgPdCu), silver indium (AgIn), and silver aluminum (AgAl). ), Silver gold (AgAu), and the like.

  The conductive layer 2 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.

  The film thickness of the conductive layer 2 is preferably in the range of 6 to 20 nm, and more preferably 6 to 15 nm. By setting the film thickness of the conductive layer 2 to 6 nm or more, the conductivity of the conductive layer 2 is sufficiently ensured. Further, it is preferable to set the film thickness of the conductive layer 2 to 20 nm or less because the absorption component or the reflection component of the conductive layer 2 can be kept low and the light transmittance of the transparent electrode 10 is maintained. Furthermore, the thickness of 15 nm or less is preferable because the light transmittance of the transparent electrode 10 is further improved.

  That is, the conductive layer 2 has a good film formation state as shown in SEM images of examples described later. Further, even in an SEM image after storage at high temperature, a fine defect portion at the time of film formation does not spread, and a thin but uniform thickness provides a stable film quality.

  Furthermore, in order not to inhibit the light transmittance of the transparent electrode 10, the thickness of the conductive layer 2 may be set so that the total thickness of the conductive layer 2 and the calcium-containing layer 1 is 22 nm or less. In particular, the total thickness is preferably 17 nm or less. By making the total thickness of the conductive layer 2 and the calcium-containing layer 1 22 nm or less, the absorption component and the reflection component of the two layers can be suppressed low, and the light transmittance of the transparent electrode 10 is maintained, which is preferable. . In particular, it is preferable to set the total thickness of the conductive layer 2 and the calcium-containing layer 1 to 17 nm or less because the light transmittance of the transparent electrode 10 is further improved.

  The film thickness ratio between the conductive layer 2 and the calcium-containing layer 1 is preferably in the range of 10: 1 to 30: 1. Thereby, the calcium (Ca) atom of the calcium-containing layer 1 and the silver (Ag) atom of the conductive layer are more likely to interact.

  As a method for forming the conductive layer 2 as described above, a method using a wet process such as a coating method, an inkjet method, a coating method, a dip method, a vapor deposition method (resistance heating, EB method, etc.), a sputtering method, a CVD method, or the like. And a method using a dry process such as a method.

  For example, in the case of forming the conductive layer 2 to which the sputtering method is applied, a sputter target of an alloy containing silver as a main component is prepared, and the sputter film formation is performed using the sputter gate. In all of the above-described alloys, the conductive layer 2 is formed by sputtering, and in particular, silver copper (AgCu), silver palladium (AgPd), or silver palladium copper (AgPdCu) is formed. In this case, the conductive layer 2 is formed by applying a sputtering method.

  In particular, in the case where silver aluminum (AgAl), silver magnesium (AgMg), or silver indium (AgIn) is formed, the conductive layer 2 to which the vapor deposition method is applied is preferably formed. In the case of a vapor deposition method, an alloy component and silver (Ag) are co-deposited. Under the present circumstances, the vapor deposition film which adjusted the addition density | concentration of the alloy component with respect to silver (Ag) which is a main material by adjusting the vapor deposition rate of an alloy component and the vapor deposition rate of silver (Ag), respectively is performed.

  In addition, the conductive layer 2 is formed on the calcium-containing layer 1 so that it has sufficient conductivity even without high-temperature annealing after the film formation, etc. It may be one that has been subjected to high-temperature annealing after film formation.

  The transparent electrode 10 having a three-layer structure in which the transparent substrate 11, the calcium-containing layer 1, and the conductive layer 2 are laminated as described above has an upper portion of the conductive layer 2 covered with a protective film, Another conductive layer (auxiliary electrode) may be laminated. In this case, it is preferable that the protective film and the other conductive layer have light transmittance so as not to impair the light transmittance of the transparent electrode 10. Moreover, it is good also as a structure which provided the layer as needed also in the lower part of the calcium containing layer 1, ie, between the calcium containing layer 1 and the transparent substrate 11, for example.

<Effect>
The transparent electrode 10 configured as described above is configured such that the calcium-containing layer 1 is provided adjacent to the conductive layer 2 between the transparent substrate 11 and the conductive layer 2 mainly composed of silver. . As a result, the transparent electrode has a lower surface resistance and improved transmittance as compared with a transparent electrode having a structure not provided with the calcium-containing layer 1 as shown in Examples described later. It becomes. In particular, as shown in the SEM images of the examples to be described later, the film-forming state of the conductive layer 2 containing silver as a main component is good, and also in the SEM image after high-temperature storage, The conductive layer 2 having a stable film quality can be formed with a uniform thickness even though it is thin without spreading minute defects.

  That is, according to such a configuration, when the conductive layer 2 is formed on the calcium-containing layer 1, the silver or silver alloy constituting the conductive layer 2 interacts at the interface with the calcium-containing layer 1. By doing so, the surface diffusion distance is reduced and aggregation is suppressed. That is, since the number of nuclei (growth nuclei) for growing the film of the conductive layer 2 is larger than usual, a continuous film having a thin but uniform thickness can be formed starting from the growth nuclei. . Still further, the interaction between calcium (Ca) constituting the calcium-containing layer 1 and silver or silver alloy constituting the conductive layer 2 suppresses migration of silver atoms, for example, by heat from the outside. The conductive layer 2 has a stable film quality.

  Therefore, the transparent electrode 10 of the present embodiment has a thin but uniform thickness and has a stable film quality conductive layer 2, and it is possible to achieve both improvement in conductivity and improvement in light transmission. It becomes possible.

  Such a transparent electrode 10 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. It will be.

≪2. Second Embodiment: Four-layered transparent electrode provided with a base layer >>
FIG. 2 is a schematic cross-sectional view showing a configuration of a transparent electrode (four-layer structure) according to the second embodiment of the present invention. The transparent electrode 20 shown in this figure is different from the transparent electrode 10 described with reference to FIG. 1 except that a base layer (optical adjustment layer) is provided between the transparent substrate 11 and the calcium-containing layer 1. The layer structure is the same, and the other configurations are the same. For this reason, the same code | symbol is attached | subjected to the same component and the overlapping description is abbreviate | omitted.

  That is, the transparent electrode 20 having a four-layer structure is provided on the transparent substrate 11 in the order of the base layer 21, the calcium-containing layer 1, and the conductive layer 2, for example.

<Underlayer>
The foundation layer 21 is a layer provided between the transparent substrate 11 and the calcium-containing layer 1. Such an underlayer 21 is a layer for improving the conductivity and light transmittance of the transparent electrode 20 as shown in Examples described later, and is disposed adjacent to the calcium-containing layer 1. However, it is characteristic.

The underlayer 21 as described above is not particularly limited, but can be appropriately selected according to the purpose. By constituting the layer with a high refractive index or a low refractive index, the light transmittance (optical) of the transparent electrode 20 is achieved. It may be a layer for adjusting (admittance). Further, there may be a layer for improving the smoothness and film quality of the conductive layer 2. The underlayer 21 may be made of an inorganic material or an organic material.
Among these, from the viewpoint of adjusting the optical characteristics such as reflectance and transmittance of the conductive layer 2 and improving the light transmittance of the transparent electrode 20, the base layer 21 is preferably an optical adjustment layer.

[1. Optical adjustment layer]
The optical adjustment layer is a layer for adjusting optical characteristics such as reflectance and transmittance of the conductive layer 2. Such an optical adjustment layer is preferably a layer having a refractive index higher than that of the transparent substrate 11 (high refractive index layer).

  The refractive index of the high refractive index layer is preferably 1.8 or more, more preferably 2.1 or more and 2.5 or less. When the refractive index of the high refractive index layer is higher than 1.8, the light transmittance of the conductive layer 2 tends to increase. Further, the refractive index of the high refractive index layer is preferably larger than the refractive index of the transparent substrate 11 by 0.1 to 1.1 or more, more preferably 0.4 to 1.0 or more. The refractive index of the high refractive index layer is the refractive index of light having a wavelength of 510 nm, and is measured with an ellipsometer. The refractive index of the high refractive index layer is adjusted by the material constituting the high refractive index layer, the density of the material in the high refractive index layer, and the like.

The high refractive index layer is preferably configured to include a dielectric material or an oxide semiconductor material. Moreover, it is preferable that the material which comprises a high refractive index layer is a metal oxide or a metal sulfide. Examples of the metal oxide or metal sulfide include titanium oxide (TiO ₂ : n = 2.1 to 2.4), indium tin oxide (ITO: n = 1.9 to 2.2), zinc oxide (ZnO : N = 1.9 to 2.0), zinc sulfide (ZnS: n = 2.0 to 2.2), niobium oxide (Nb ₂ O ₅ : n = 2.2 to 2.4), zirconium oxide ( ZrO ₂ : n = 2.0.-2.1), cerium oxide (CeO ₂ : n = 1.9-2.2), tantalum pentoxide (Ta ₂ O ₅ : n = 1.9-2.2) ), Tin oxide (SnO ₂ : n = 1.8 to 2.0), indium zinc oxide (IZO: 1.9 to 2.4), etc., and TiO ₂ and Nb from the viewpoint of refractive index and productivity. ₂ O ₅ is preferred. The high refractive index layer may include only one type of dielectric material or oxide semiconductor material, or may include two or more types.

  The thickness of the high refractive index layer is preferably 10 to 150 nm, more preferably 20 to 80 nm. Here, when the thickness of the high refractive index layer is less than 10 nm, it is difficult to sufficiently increase the light transmittance of the conductive layer 2. On the other hand, when the thickness of the high refractive index layer exceeds 150 nm, the transparency (antireflection property) of the conductive layer 2 does not increase. The thickness of the high refractive index layer is measured with an ellipsometer.

The optical adjustment layer may be a layer having a refractive index lower than that of the transparent substrate 11 (low refractive index layer). In addition to the above-described high refractive index layer, a low refractive index layer may be further provided, or a plurality of high refractive index layers and low refractive index layers may be stacked. By forming such a low refractive index layer adjacent to the high refractive index layer, the light transmittance of the transparent electrode 20 is further improved.
If the optical adjustment layer is composed of a high refractive index layer and a low refractive index layer, the high refractive index layer and the low refractive index layer are laminated in this order on the transparent substrate 11. .

The low refractive index layer is a layer having a refractive index lower than that of the transparent substrate 11 and is a layer having a refractive index lower than that of the transparent substrate 11 and the high refractive index layer when used together with the high refractive index layer.
In this case, it is preferable that the transparent substrate 11 is made of a material having a refractive index lower than that of the high refractive index layer, and the refractive index of the low refractive index layer is particularly 0.1 or more lower than that of the transparent substrate 11 at a wavelength of 510 nm. Such a low refractive index layer is not particularly limited, and includes a material having a refractive index lower than that of the material constituting the transparent substrate 11.

(Method for forming optical adjustment layer)
When the optical adjustment layer as described above is formed on the transparent substrate 11, examples of the film formation method include vapor deposition methods (resistance heating, EB method, etc.) or sputtering methods. In particular, a method using ion assist is suitable for EB deposition. As a method for forming such an optical adjustment layer, an appropriate method is selected depending on the material constituting the optical adjustment layer. For example, a vapor deposition method is preferably applied as long as the optical adjustment layer is formed using zinc oxide (ZnO) or titanium oxide (TiO ₂ ). A sputtering method is preferably applied as long as the optical adjustment layer is formed using indium oxide (In ₂ O ₃ ), indium tin oxide (ITO), or niobium oxide (Nb ₂ O ₅ ).

[2. Other layers]
The foundation layer 21 may be a smooth layer for improving the smoothness of the conductive layer 2, for example. The underlayer 21 may be a layer composed of a compound that interacts with the silver atoms constituting the conductive layer 2 and is stably bonded. For example, a nitrogen-containing compound containing nitrogen is used. It is done. By providing such a layer on the base of the calcium-containing layer 1, it is possible to improve the film quality due to the smoothness of the conductive layer 2 and the synergistic effect with the calcium-containing layer.

  The transparent electrode 20 having the four-layer structure in which the transparent substrate 11, the base layer 21, the calcium-containing layer 1, and the conductive layer 2 are stacked as described above has a protective film on the top of the conductive layer 2. It may be covered or another conductive layer may be laminated. In this case, it is preferable that the protective film and the other conductive layer have light transmittance so as not to impair the light transmittance of the transparent electrode 20. Further, a configuration in which a layer according to need is provided below the base layer 21, that is, between the base layer 21 and the transparent substrate 11, for example, may be employed.

<Effect>
The transparent electrode 20 configured as described above has a four-layer structure in which a base layer (optical adjustment layer) 21 is provided between the transparent substrate 11 and the calcium-containing layer 1 in the transparent electrode 10 shown in FIG. It is. Thereby, in addition to the effect of 1st Embodiment, the transparent electrode 20 can aim at coexistence with the improvement of electroconductivity, and the improvement of light transmittance, and the improvement of the reliability was achieved.

  In particular, when the base layer 21 is formed of an optical adjustment layer, it is possible to adjust optical characteristics such as reflectance and transmittance of the conductive layer 2 and reduce the original absorption of the metal material. . That is, the optical admittance of the conductive layer 2 can be adjusted in accordance with the medium on the light incident side of the conductive layer 2, and reflection at the interface with the medium can be prevented. As a result, the transparent electrode 20 is further improved in light transmittance and improved viewing angle characteristics of chromaticity. In addition, when a plurality of optical adjustment layers are used, the range in which the optical admittance of the transparent electrode 20 can be optimized is widened, so that the degree of freedom in design is improved.

≪3. Third Embodiment: Five-layered transparent electrode provided with an optical adjustment layer >>
FIG. 3 is a schematic cross-sectional view showing the configuration of a transparent electrode (five-layer structure) according to the third embodiment of the present invention. The transparent electrode 30 shown in this figure is different from the transparent electrode 20 described with reference to FIG. 2 in that an optical adjustment layer is provided on the surface of the conductive layer opposite to the side where the calcium-containing layer is provided. The other structure is the same. For this reason, the same code | symbol is attached | subjected to the same component and the overlapping description is abbreviate | omitted.

  That is, the transparent electrode 30 having a five-layer structure is provided on the transparent substrate 11 in the order of the base layer 21, the calcium-containing layer 1, the conductive layer 2, and the optical adjustment layer 31, for example.

<Optical adjustment layer>
The optical adjustment layer 31 may be the same as the optical adjustment layer in the base layer 21 used in the transparent electrode 20 having the four-layer structure shown in FIG. In other words, the optical adjustment layer 31 is a layer that adjusts light transmittance (optical admittance) by being composed of a high refractive index layer or a low refractive index layer. When the optical adjustment layer 31 is composed of a high refractive index layer and a low refractive index layer, a configuration in which the high refractive index layer and the low refractive index layer are laminated in this order on the conductive layer 2. And

  Further, as the material constituting the optical adjustment layer 31, the material exemplified when the base layer 21 shown in FIG. 2 is the optical adjustment layer is also used, but the optical adjustment arranged with the conductive layer 2 interposed therebetween. The layers may be composed of the same material as each other or may be composed of different materials.

  Further, the thickness of the optical adjustment layer 31 may be the same as or different from that of the optical adjustment layer of the base layer 21 shown in FIG. 2, but is formed with a thickness of 10 to 100 nm. It is preferable. By setting the thickness within this range, reflection at the interface between the conductive layer 2 and the optical adjustment layer 31 can be prevented. In particular, by setting the thickness to 20 nm or more, it is effective for suppressing reflection.

  Here, the optical adjustment layer 31 is a layer formed on the conductive layer 2. For this reason, when such a transparent electrode 30 is used for an electronic device, the optical adjustment layer 31 is provided between the conductive layer 2 that is the main body of the electrode and an element or electronic component that is disposed on the transparent electrode 30. It becomes the structure which intervenes. Thus, even when the optical adjustment layer 31 is interposed, the optical adjustment layer 31 does not affect the conductivity of the electronic device using the transparent electrode 30. This is because the optical adjustment layer 31 hardly affects the conductivity of the transparent electrode 30 because silver or a silver alloy constituting the conductive layer 2 has very high conductivity.

For example, even when the resistance value in the surface direction of the optical adjustment layer 31 is high, the conductivity in the surface direction of the transparent electrode 30 is influenced by the optical adjustment layer 31 because the conductivity of the conductive layer 2 is very high. Not receive.
That is, the resistance in the thickness direction of the optical adjustment layer 31 is very small at the thickness of the optical adjustment layer 31 and the conductivity of the conductive layer 2 is very high. Conductivity is not affected.

  In addition, what is necessary is just to set the film thickness of the optical adjustment layer 31 to the value suitably set with the electronic device comprised using this transparent electrode 30, if it is in the range mentioned above.

  Further, the optical adjustment layer 31 can be formed into a dense layer by using, for example, the above-described vapor deposition method (resistance heating, EB method, etc.) or a sputtering method. Thus, by forming the dense optical adjustment layer 31 in contact with the conductive layer 2, silver or a silver alloy constituting the conductive layer 2 can be stabilized (immobilized). For this reason, the reliability of the conductive layer 2 is improved, and the reliability of the transparent electrode 30 and the performance of the electronic device including the transparent electrode 30 are improved.

  Note that the transparent electrode 30 having the five-layer structure in which the transparent substrate 11, the base layer 21, the calcium-containing layer 1, the conductive layer 2, and the optical adjustment layer 31 are stacked as described above is the optical adjustment layer 31. May be covered with a protective film, or another conductive layer may be laminated. In this case, it is preferable that the protective film and the other conductive layer have light transmittance so that the light transmittance of the transparent electrode 30 is not impaired. Further, a configuration in which a layer according to need is provided below the base layer 21, that is, between the base layer 21 and the transparent substrate 11 may be employed.

  Moreover, although this embodiment demonstrated the structure which provides the optical adjustment layer 31 in the transparent electrode 20 shown in FIG. 2, you may combine with the transparent electrode 10 shown in FIG.

<Effect>
The transparent electrode 30 configured as described above has five layers in which the optical adjustment layer 31 is provided on the surface of the transparent electrode 20 shown in FIG. 2 opposite to the side on which the calcium-containing layer 1 is provided. This is a structured structure. Thereby, in addition to the effect of 2nd Embodiment, the transparent electrode 30 can aim at the improvement of a light transmittance further.

  That is, according to such a configuration, reflection at the interface between the conductive layer 2 and the optical adjustment layer 31 can be prevented. Further, in the case of the optical adjustment layer 31 using a high refractive index layer, the material of the high refractive index layer described above generally has a dense film quality, and thus is disposed adjacent to the conductive layer 2. Thus, migration of silver (Ag) constituting the conductive layer 2 can be prevented. As a result, the reliability is further improved.

  In particular, when the base layer 21 is formed of an optical adjustment layer, the transparent electrode 30 has a configuration in which the conductive layer 2 and the calcium-containing layer 1 are sandwiched between the optical adjustment layers. Thereby, it becomes possible to adjust optical characteristics, such as a reflectance of the electroconductive layer 2, and a transmittance | permeability, and metal material original absorption can be reduced. That is, the optical admittance of the conductive layer 2 can be adjusted in accordance with the medium on the light incident side of the conductive layer 2, and reflection at the interface with the medium can be prevented. As a result, the transparent electrode 30 is further improved in light transmittance and improved viewing angle characteristics of chromaticity.

  Further, the transparent electrode in the case where the present embodiment and the first embodiment are combined can further improve the light transmittance in addition to the effects of the first embodiment, and the reliability can be further improved. It will be.

<< 4. Fourth Embodiment: Use of Transparent Electrode >>
The transparent electrode of the first to third embodiments described above can be used for various electronic devices. Examples of electronic devices include organic EL elements, LEDs (light emitting diodes), liquid crystal elements, solar cells, touch panels, and the like. And when a light transmittance is required as an electrode member of these electronic devices, the transparent electrode of 1st-3rd embodiment can be used preferably.

  Hereinafter, as an example of the application, an embodiment of an electronic device (organic EL element) using the transparent electrode of the present invention as an anode or / and a cathode will be described. Here, the transparent electrode 10 according to the first embodiment will be described as an example of the transparent electrode of the present invention.

≪5. Fifth Embodiment: Electronic Device (Organic EL Element) >>
<Configuration of organic EL element>
FIG. 4 is a cross-sectional configuration diagram showing a configuration example of an organic EL element using the transparent electrode 10 described above as an example of the electronic device of the present invention. Below, the structure of the organic EL element 40 is demonstrated based on this figure.

  In the organic EL element 40 shown in FIG. 4, the light emitting functional layer 3 and the counter electrode 5 are laminated in order from the conductive layer 2 side of the transparent electrode 10. The light emitting functional layer 3 includes a light emitting layer 3a made of at least an organic material. Therefore, the organic EL element 40 is configured as a bottom emission type that takes out the emitted light h from at least the transparent substrate 11 side.

  The organic EL element 40 is sealed on the transparent substrate 11 with a sealing material described later for the purpose of preventing deterioration of the light emitting functional layer 3 formed using an organic material or the like. This sealing material is fixed to the transparent substrate 11 side through an adhesive. However, it is assumed that the terminal portions of the transparent electrode 10 and the counter electrode 5 are provided on the transparent substrate 11 so as to be exposed from the sealing material while being insulated from each other by the light emitting functional layer 3.

  Hereinafter, the detail of each main layer for comprising the organic EL element 40 mentioned above is demonstrated in order of the transparent electrode 10, the light emission functional layer 3, the counter electrode 5, a sealing material, and a protection member. Thereafter, a method for producing the organic EL element 40 will be described.

[1. Transparent electrode]
The transparent electrode is the transparent electrode 10 of the present invention described above and is an electrode constituting the anode or the cathode of the organic EL element 40 and provided on the side from which the emitted light h generated in the light emitting functional layer 3 is extracted. Electrode. The transparent electrode 10 has a configuration in which a calcium-containing layer 1 and a conductive layer 2 are provided in this order on the transparent substrate 11. Here, in particular, the layer constituting the conductive layer 2 is a substantial electrode.

  In addition, although the transparent electrode in the organic EL element 40 of this embodiment is demonstrated using the transparent electrode 10 shown in FIG. 1, for example, in the case of the transparent electrode 30 shown in FIG. The optical adjustment layer 31 is arranged between the conductive layer 2 used as a typical electrode. Thus, even in the transparent electrode 30 in which the optical adjustment layer 31 is interposed between the light emitting functional layer 3, the conductivity of the conductive layer 2 mainly composed of silver (Ag) is extremely high. No conductivity is required for 31. Therefore, the material of the optical adjustment layer 31 may be appropriately selected.

  The optical adjustment layer 31 does not need to have a film thickness necessary as an electrode, and is appropriately set depending on the arrangement state of the transparent electrode 30 in the organic EL element in which the transparent electrode 30 including the optical adjustment layer 31 is used. What is necessary is just to have the made film thickness.

[2. Light emitting functional layer]
The light emitting functional layer 3 is a layer including a light emitting layer 3a composed of at least an organic material. The overall layer structure of the light emitting functional layer 3 is not limited and may be a general layer structure. In addition, as an example, the light emitting functional layer 3 includes, in order from the electrode side used as the anode among the transparent electrode 10 and the counter electrode 5 [hole injection layer / hole transport layer / light emitting layer 3a / electron transport layer / electron injection layer]. ] Is laminated, but layers other than the light emitting layer 3a are provided as necessary.

  Among these, the light emitting layer 3a is a layer that emits light by recombination of electrons injected from the cathode side and holes injected from the anode side, and the light emitting portion is in the layer of the light emitting layer 3a. May also be an interface with an adjacent layer in the light emitting layer 3a. Such a light emitting layer 3a may contain a phosphorescent light emitting material as a light emitting material, may contain a fluorescent light emitting material, or may contain both a phosphorescent light emitting material and a fluorescent light emitting material. In addition, the light emitting layer 3a preferably has a structure in which these light emitting materials are used as guest materials and further contain a host material.

  The hole injection layer and the hole transport layer may be provided as a hole transport injection layer having a hole transport property and a hole injection property. When the optical adjustment layer 31 is made of a metal oxide, many of the exemplified metal oxides have a hole transport property or a hole injection property. It can also be used as a hole transport layer or a hole transport injection layer.

  The electron transport layer and the electron injection layer may be provided as an electron transport injection layer having electron transport properties and electron injection properties. Among these layers, for example, the hole injection layer and the electron injection layer 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.

  Further, the light emitting functional layer 3 may have a structure in which a plurality of light emitting functional layers including each color light emitting layer 3a that generates light emitted in each wavelength region are stacked. Each light emitting functional layer may have a different layer structure, and may be laminated directly or via an intermediate layer. The intermediate layer is generally one of an intermediate electrode, an intermediate conductive layer, a charge generation layer, an electron extraction layer, a connection layer, and an intermediate insulating layer. Electrons are positively connected to the anode side adjacent layer and positive to the cathode side adjacent layer. A known material configuration can be used as long as the layer has a function of supplying holes.

(Method for forming light emitting functional layer)
The light emitting functional layer 3 as described above is formed by sequentially forming a material constituting each layer by a known thin film forming method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, an ink jet method, and a printing method. Can be obtained. The vacuum deposition method or the spin coating method is particularly preferable from the viewpoint that a homogeneous film is easily obtained and pinholes are hardly generated. 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 select each condition as appropriate within 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 nm to 5 μm.

[3. Counter electrode]
The counter electrode 5 is provided in a state in which the light emitting functional layer 3 is sandwiched between the transparent electrode 10 and is used as a cathode when the transparent electrode 10 is an anode, and an anode when the transparent electrode 10 is a cathode. Used as The counter electrode 5 is configured using a conductive material appropriately selected in consideration of a work function from among metals, alloys, organic or inorganic conductive compounds, and mixtures thereof. 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 .

  If the organic EL element 40 is configured to extract the emitted light h only from the transparent substrate 11 side, a material having a good reflection characteristic of the emitted light h is selected from the conductive materials described above and the counter electrode 5 is selected. It is preferable to constitute. On the other hand, if the organic EL element 40 is a double-sided light emitting type that also takes out the emitted light h from the counter electrode 5 side, a conductive material with good light transmission is selected from the above-described conductive materials, and the counter electrode is selected. 5 may be configured.

  Although the thickness of the counter electrode 5 depends on the material, it is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm in consideration of transparency or reflectivity.

(Counter electrode deposition method)
The counter electrode 5 as described above is formed by a method such as vapor deposition or sputtering of a selected conductive material.

[4. Encapsulant]
The sealing material covers the organic EL element 40 and may or may not have optical transparency. However, when the organic EL element 40 extracts the emitted light h from the counter electrode 5 side, a light-transmitting transparent sealing material is used as the sealing material. Such a sealing material may be a plate-like (film-like) sealing member that is fixed to the transparent substrate 11 side by an adhesive, or may be a sealing film.

  Specific examples of the plate-like (film-like) sealing material include a glass substrate and a polymer substrate as long as they have optical transparency, and these substrate materials are used in the form of a thin film. May be. 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 in accordance with the above is 1 × 10 ⁻³ g / (m ² · 24 h) or less. preferable.

  Further, the above substrate material may be processed into a concave plate shape and used as a sealing material. Moreover, what was comprised with the metal material as another example of a plate-shaped sealing material can be used.

  Further, the adhesive for fixing the plate-shaped sealing material as described above to the transparent substrate 11 side is a seal for sealing the organic EL element 40 sandwiched between the sealing material and the transparent substrate 11. Used as an agent. In addition, the organic material which comprises the organic EL element 40 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.

  Further, when a gap is formed between the plate-shaped sealing material, the transparent substrate 11, and the adhesive, the gap includes an inert gas such as nitrogen or argon or a fluorinated hydrocarbon in the gas phase and the liquid phase. Preferably, an inert liquid such as silicon oil is injected. A vacuum is also possible. Moreover, a hygroscopic compound can also be enclosed inside.

  On the other hand, when a sealing film is used as the sealing material, the transparent functional layer 3 in the organic EL element 40 is completely covered and the transparent electrode 10 and the counter electrode 5 in the organic EL element 40 are exposed, and the transparent film is exposed. A sealing film is provided on the substrate 11.

  Such a sealing film is configured using an inorganic material or an organic material, and in particular, a material having a function of suppressing intrusion of moisture, oxygen, or the like, for example, an inorganic material such as silicon oxide, silicon dioxide, or silicon nitride. 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.

  The sealing material as described above is provided in a state where the terminal portions of the transparent electrode 10 and the counter electrode 5 in the organic EL element 40 are exposed and at least the light emitting functional layer 3 is covered. Moreover, an electrode may be provided on the sealing material so that the transparent electrode 10 of the organic EL element 40 and the terminal portions of the counter electrode 5 are electrically connected to this electrode.

[5. Protective member]
Although illustration is omitted here, a protective member may be provided between the transparent substrate 11 and the organic EL element 40 and a sealing material. This protective member is for mechanically protecting the organic EL element 40, and particularly when the sealing material is a sealing film, mechanical protection for the organic EL element 40 is not sufficient, It is preferable to provide such a protective member.

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

<Method for producing organic EL element>
The production of the organic EL element 40 as described above is performed as follows.

  First, the calcium-containing layer 1 is formed on the transparent substrate 11 so as to have a film thickness of 2 nm or less. Next, the conductive layer 2 made of silver (or an alloy containing silver as a main component) is formed to have a film thickness of 6 nm to 20 nm. In the above film formation, an appropriate film formation method such as the above-described vapor deposition method or sputtering method is applied. In forming the conductive layer 2, the conductive layer 2 is formed in a shape in which a terminal portion is drawn around the periphery of the transparent substrate 11 by performing film formation using, for example, a mask as necessary.

  Next, the light emitting functional layer 3 including the light emitting layer 3 a is formed on the conductive layer 2. Film formation of each layer constituting the light emitting functional layer 3 is performed by applying an appropriately selected film formation method. In forming the light-emitting functional layer 3, the light-emitting functional layer 3 is formed in a shape that exposes the terminal portion of the conductive layer 2 by performing film formation using a mask, for example, as necessary. Each layer is formed.

  Next, the counter electrode 5 is formed on the light emitting functional layer 3. The counter electrode 5 is formed by applying an appropriate film forming method such as vapor deposition or sputtering. Further, in forming the counter electrode 5, for example, by using a mask as necessary, the periphery of the transparent substrate 11 is maintained while maintaining the insulating state between the light emitting functional layer 3 and the conductive layer 2. The terminal part of the counter electrode 5 is formed in a shape drawn out.

  Thus, the bottom emission type organic EL element 40 that takes out the emitted light h from the transparent substrate 11 side is obtained. Thereafter, a sealing material that covers at least the light-emitting functional layer 3 is provided in a state where the conductive layer 2 and the terminal portion of the counter electrode 5 in the organic EL element 40 are exposed. At this time, the sealing material is bonded to the transparent substrate 11 side using an adhesive, and the light emitting functional layer 3 of the organic EL element 40 is sealed between the sealing material and the transparent substrate 11.

  In the production of the organic EL element 40 as described above, it is preferable to produce from the light emitting functional layer 3 to the counter electrode 5 consistently by a single evacuation. However, the transparent substrate 11 is taken out from the vacuum atmosphere on the way and is different. A film forming method may be applied. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  In addition, formation of the calcium containing layer 1-the counter electrode 5 mentioned above may be made to pattern each layer formed into a predetermined shape after forming each layer into a film. In addition, before and after the formation of the conductive layer 2, an auxiliary electrode pattern may be formed as necessary.

  When a direct current voltage is applied to the organic EL element 40 thus obtained, light emission can be observed by applying a voltage of about 2 V to about 40 V between the conductive layer 2 and the counter electrode 5. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

<Effect>
The organic EL element 40 configured as described above uses the transparent electrode 10 having both conductivity and light transmittance as an electrode on the side from which the emitted light h is extracted, and between the calcium-containing layer 1 of the transparent electrode 10. The light emitting functional layer 3 is provided at a position where the conductive layer 2 is sandwiched, and the counter electrode 5 is provided between the transparent electrode 10 and the light emitting functional layer 3.
As a result, the organic EL element 40 has an improved lifetime due to a reduction in driving voltage for obtaining a predetermined luminance and chromaticity as shown in examples described later. Therefore, the device performance is improved.

  That is, the organic EL element 40 is provided with the transparent electrode 10 having good conductivity and light transmissivity, so that the lifetime is improved by reducing the driving voltage for obtaining a predetermined luminance and chromaticity. Improvement will be achieved.

Further, when the transparent electrode 20 shown in FIG. 2 or the transparent electrode 30 shown in FIG. 3 is used as the transparent electrode, the organic EL element can further reduce the driving voltage in addition to the above effects, thereby improving the lifetime. As a result, the performance is further improved.
In particular, when the transparent electrode 20 or the base layer 21 of the transparent electrode 30 is formed of an optical adjustment layer, it is possible to adjust the optical characteristics such as reflectance and transmittance of the conductive layer 2, and a metal material. The original absorption can be reduced. Therefore, in the case of an organic EL device using a transparent electrode having such an optical adjustment layer, the driving voltage can be further suppressed in addition to the above-described effect, thereby improving the lifetime, and in particular, the viewing angle of chromaticity. The characteristics are improved. Therefore, the device performance is further improved.

≪6. Sixth Embodiment: Use of Electronic Device (Organic EL Element) >>
The organic EL element 40 shown in FIG. 4 can be applied as an electronic device such as a display device, a display, and various light emission sources. Examples of light sources include lighting devices such as home lighting and interior lighting, backlights for watches and liquid crystals, lighting for billboard advertisements, light sources for traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, and optical communication. Examples include, but are not limited to, a light source of a processing machine and a light source of an optical sensor. In particular, it can be effectively used as a backlight of a liquid crystal display device combined with a color filter and a light source for illumination.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to a following example.

≪Preparation of transparent electrode≫
As shown in the following Table 1, each of the transparent electrodes of Samples 101 to 138 was fabricated so that the area of the conductive region was 5 cm × 5 cm.

<Procedure for producing transparent electrode of sample 101>
A conductive layer made of silver (Ag) with a thickness of 10 nm was formed as a transparent electrode on a glass transparent substrate as follows.

First, a transparent alkali-free glass substrate was fixed to a substrate holder of a commercially available vacuum deposition apparatus, and silver (Ag) was placed in a resistance heating boat made of tungsten. Next, these substrate holders and a heating boat were mounted in a vacuum chamber. Next, after reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the resistance heating boat was energized and heated, and the deposition rate was 0.1 nm / second to 0.2 nm / second, and the film was formed from 10 nm thick silver (Ag). A conductive layer was formed.

<Procedure for Producing Transparent Electrode of Sample 102>
A transparent electrode of Sample 102 was prepared in the same procedure as Sample 101, except that the transparent substrate was formed of a polyethylene terephthalate (PET) substrate.

<Procedure for Producing Transparent Electrode of Sample 103>
A transparent electrode of Sample 103 was prepared in the same procedure as Sample 101 except that the transparent substrate was formed of a polyethylene naphthalate (PEN) substrate.

<Procedure for Producing Transparent Electrode of Sample 104>
A transparent electrode of Sample 104 was prepared in the same manner as Sample 101 except that a base layer composed of titanium oxide (TiO ₂ ) was formed before forming the conductive layer as follows. .

First, a transparent substrate made of glass was fixed to a substrate holder of a commercially available electron beam evaporation apparatus, and titanium oxide (TiO ₂ ) was placed in a hearth liner made of copper (Cu). Next, these substrate holders and hearth liners were mounted in a vacuum chamber of an electron beam evaporation apparatus. Moreover, silver (Ag) was put into the resistance heating boat made from tungsten, and it attached to the vacuum chamber of a commercially available vacuum evaporation system.

Next, the vacuum chamber of the electron beam evaporation apparatus is depressurized to 2 × 10 ⁻² Pa, and then a copper (Cu) hearth liner containing titanium oxide (TiO ₂ ) is irradiated with an electron beam and heated to evaporate the film. An underlayer composed of titanium oxide (TiO ₂ ) having a thickness of 30 nm and a thickness of 0.1 nm / second to 0.2 nm / second was provided.

  Next, a conductive layer made of silver was formed on the transparent substrate formed up to the base layer by the same procedure as described in the procedure for manufacturing the sample 101.

<Procedure for Producing Transparent Electrode of Sample 105>
The transparent electrode of the sample 105 was formed in the same manner as the sample 101 except that the base layer composed of niobium oxide (Nb ₂ O ₅ ) was formed before forming the conductive layer as follows. Produced.

First, a glass transparent substrate was fixed to a substrate holder of a commercially available sputter deposition apparatus, and a sputter target composed of niobium oxide (Nb ₂ O ₅ ) was attached to a vacuum chamber of the sputter deposition apparatus. Moreover, silver (Ag) was put into the resistance heating boat made from tungsten, and it attached to the vacuum chamber of a commercially available vacuum evaporation system.

Next, after reducing the vacuum chamber of the sputter deposition apparatus to 4 × 10 ⁻⁴ Pa, argon gas is introduced, the inside of the vacuum chamber is adjusted to 0.4 Pa, RF (high frequency) bias is 300 W, and the deposition rate is increased. An underlayer composed of niobium oxide (Nb ₂ O ₅ ) with a thickness of 30 nm and a thickness of 0.2 nm / second was provided.

  Next, a conductive layer made of silver was formed on the transparent substrate formed up to the base layer by the same procedure as described in the procedure for manufacturing the sample 101.

<Procedure for producing transparent electrodes of samples 106 to 110>
Transparent electrodes of Samples 106 to 110 were prepared in the same procedure as Sample 105 except that the underlayer was formed of each compound shown in Table 1 below.

<Procedure for Producing Transparent Electrodes of Samples 111 and 112>
The transparent electrodes of Samples 111 and 112 were processed in the same manner as Sample 101, except that a base layer composed of each compound shown in Table 1 was formed before forming the conductive layer as follows. Was made.

  First, a transparent substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, and each compound shown in Table 1 below is placed in a resistance heating boat made of tantalum, and these substrate holder and resistance heating boat are connected to the first of the vacuum deposition apparatus. Installed in a vacuum chamber. Moreover, silver (Ag) was put into the resistance heating boat made from tungsten, and it attached in the 2nd vacuum chamber of a vacuum evaporation system.

  The organic material A and the organic material B of the compound used here are nitrogen-containing compounds containing nitrogen.

Next, after reducing the pressure in the first vacuum tank to 4 × 10 ⁻⁴ Pa, the heating boat containing the respective compounds was energized and heated, and on the transparent substrate at a deposition rate of 0.1 nm / second to 0.2 nm / second. An underlayer having a thickness of 30 nm was formed on the substrate.

  Next, the transparent substrate formed up to the base layer was transferred to the second vacuum chamber in a vacuum, and a conductive layer made of silver was formed in the same procedure as described in the procedure for manufacturing the sample 101.

<Procedure for Producing Transparent Electrode of Sample 113>
The transparent electrode of the sample 113 was formed in the same procedure as the transparent electrode of the sample 101 except that a calcium-containing layer composed of calcium (Ca) was formed before forming the conductive layer as follows. Produced.

  First, a transparent substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, calcium (Ca) is placed in a resistance heating boat made of tantalum, and these substrate holder and resistance heating boat are placed in the first vacuum chamber of the vacuum deposition apparatus. Attached to. Moreover, silver (Ag) was put into the resistance heating boat made from tungsten, and it attached in the 2nd vacuum chamber of a vacuum evaporation system.

Next, after reducing the pressure of the first vacuum tank to 4 × 10 ⁻⁴ Pa, the heating boat containing calcium (Ca) is energized and heated, and transparent at a deposition rate of 0.1 nm / second to 0.2 nm / second. A calcium-containing layer having a thickness of 1 nm was formed on the substrate.

  Next, the transparent substrate formed up to the calcium-containing layer was transferred to the second vacuum chamber in a vacuum, and a conductive layer made of silver was formed in the same procedure as described in the procedure for preparing Sample 101.

<Procedure for producing transparent electrodes of samples 114 and 115>
Transparent electrodes of Samples 114 and 115 were produced in the same procedure as Sample 113 except that the transparent substrate was formed of the material shown in Table 1 below.

<Procedure for Producing Transparent Electrodes of Samples 116-122>
After forming the base layer in the procedure of Samples 104 to 110, a calcium-containing layer composed of calcium (Ca) was formed before forming the conductive layer, and transparent electrodes of Samples 116 to 122 were produced. The calcium-containing layer was produced using the same procedure as that of the sample 113.

<Procedure for Producing Transparent Electrodes of Samples 123 and 124>
After forming the base layer in the procedures of Samples 111 and 112, before forming the conductive layer, a calcium-containing layer composed of calcium (Ca) was formed, and transparent electrodes of Samples 123 and 124 were manufactured. The calcium-containing layer was produced using the same procedure as that of the sample 113.

<Procedure for producing transparent electrode of sample 125>
A transparent electrode of Sample 125 was produced in the same manner as Sample 117 except that the conductive layer was formed of silver palladium (AgPd) as follows.

First, a glass transparent substrate was fixed to a substrate holder of a commercially available sputter deposition apparatus, and a sputter target composed of niobium oxide (Nb ₂ O ₅ ) was attached to a vacuum chamber of the sputter deposition apparatus. Moreover, calcium (Ca) is put into a resistance heating boat made of tantalum and attached in the first vacuum tank of the vacuum evaporation apparatus, and silver (Ag) and palladium (Pd) are put into each resistance heating boat made of tungsten, and vacuum evaporation is performed. Installed in the second vacuum chamber of the apparatus.

Next, an underlayer composed of niobium oxide (Nb ₂ O ₅ ) was formed in the vacuum chamber of the sputter deposition apparatus in the same procedure as described in the procedure for manufacturing the sample 105.

  Next, a calcium-containing layer composed of calcium (Ca) in the first vacuum chamber of the vacuum evaporation apparatus was formed in the same procedure as described in the procedure for manufacturing the sample 113.

Next, after depressurizing the second vacuum tank of the vacuum evaporation system to 4 × 10 ⁻⁴ Pa, palladium (Pd) was added to Ag at 5 atm% by co-evaporation with the evaporation rate adjusted by adjusting the current to the resistance heating boat. A conductive layer was formed.

<Procedure for Producing Transparent Electrodes of Samples 126 and 127>
Transparent electrodes of Samples 126 and 127 were prepared in the same procedure as Sample 125 except that the conductive layer was formed of each compound shown in Table 1 below.

<Procedure for Producing Transparent Electrodes of Samples 128 to 132>
Transparent electrodes of Samples 128 to 132 were prepared in the same procedure as Sample 117 except that the calcium-containing layer was formed with each film thickness shown in Table 1 below.

<Procedure for Producing Transparent Electrodes of Samples 133 to 137>
Transparent electrodes of Samples 133 to 137 were prepared in the same procedure as Sample 117 except that the conductive layers were formed with respective film thicknesses shown in Table 1 below.

<Procedure for Producing Transparent Electrode of Sample 138>
A transparent electrode of Sample 138 was prepared in the same procedure as Sample 117 except that an optical adjustment layer composed of niobium oxide (Nb ₂ O ₅ ) was formed after the conductive layer was formed. Note that the optical adjustment layer made of niobium oxide (Nb ₂ O ₅ ) was prepared using the same procedure as that for the underlayer of the sample 105.

<Procedure for Producing Sample 124 ', 124 "Transparent Electrode>
Transparent electrodes of Samples 124 ′ and 124 ″ were prepared in the same procedure as Sample 124 except that the calcium-containing layers were formed with thicknesses of 0.1 nm and 3.0 nm, respectively.

<Evaluation 1 of each sample of Example 1>
About each transparent electrode of the samples 101-138 produced above, (1) the light transmittance with respect to the light of wavelength 550nm, and (2) surface resistance were measured.

(1) The light transmittance was measured using a spectrophotometer (U-3300 manufactured by Hitachi, Ltd.) and using the same transparent substrate as the sample as a baseline.
(2) The surface resistance 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 configuration of Samples 101 to 138 and the measurement results of transmittance (%) and sheet resistance (Ω / sq.) Are shown in Table 1 below.

<Evaluation result 1 of Example 1>
As is clear from Table 1, when comparing each transparent electrode of Samples 101 to 103, 113 to 115, that is, each transparent electrode that differs only in having a calcium-containing layer between the transparent substrate and the conductive layer, Although each of the transparent electrodes of the samples 113 to 115 having the containing layer has a light transmittance of 61% or more, the sheet resistance value is also 13.7 Ω / sq. It was confirmed that the transparent electrode was compatible with both improved conductivity and improved light transmission.
This was also confirmed from a comparison of the evaluation results of the transparent electrodes of Samples 104 to 112 and Samples 116 to 124, which differ only in having a calcium-containing layer between the transparent substrate and the conductive layer.

  Moreover, when comparing each transparent electrode of the sample 113 and the samples 116 to 124, that is, each transparent electrode that is different only in having an underlayer between the transparent substrate and the calcium-containing layer, the samples 116 to 124 having the underlayer are compared. Each transparent electrode has a higher transmittance of 62% or more and a sheet resistance of 12.8 Ω / sq. It was confirmed that the following can be further suppressed.

  Further, comparing each transparent electrode of samples 123 and 124, that is, each transparent electrode that is different only in the compound constituting the underlayer, sample 124 having the underlayer composed of organic material B was composed of organic material A. It was confirmed that the sheet resistance was further improved as compared with the sample 123 having the underlayer. From this result, it is considered that the underlayer is preferably an underlayer having a high content of nitrogen that interacts with silver atoms and stably bonds.

  Further, comparing each transparent electrode of Sample 117 and Samples 125 to 127, that is, each transparent electrode that is different only in the compound constituting the conductive layer, Sample 125 having the conductive layer composed of an alloy containing silver as a main component. It was confirmed that each transparent electrode of -127 has a favorable light transmittance. On the other hand, it was confirmed that the transparent electrode of the sample 117 having a conductive layer made of silver had a favorable surface resistance.

  Further, when comparing the transparent electrodes of Sample 117 and Samples 128 to 132, that is, transparent electrodes that differ only in the thickness of the calcium-containing layer, Sample 117 having a calcium-containing layer having a thickness of 2 nm or less. , 128 to 131 have a transmittance as high as 61% or more and a surface resistance of 13.4 Ω / sq. It is suppressed to the following. Further, each of the transparent electrodes of the samples 117 and 129 to 131 in which the film thickness of the calcium-containing layer is in the range of 0.1 to 2 nm has a higher light transmittance and surface resistance than the samples outside this numerical range. It was confirmed that it was suppressed. In particular, in the transparent electrodes of the samples 117, 130, and 131 in which the thickness of the calcium-containing layer is in the range of 0.5 to 2 nm, the light transmittance is higher than that of the sample outside this numerical range. It was confirmed that the resistance was suppressed.

  Moreover, when each transparent electrode of the sample 117 and the samples 133-137, ie, each transparent electrode from which only the film thickness of an electroconductive layer differs is compared, the sample which has the electroconductive layer comprised in the range of 6-20 nm in film thickness Each of the transparent electrodes 117 and 134 to 136 has a transmittance as high as 60% or more and a surface resistance of 11.3 Ω / sq. It is suppressed to the following. Further, in each of the samples 117, 134, and 135 in which the film thickness of the conductive layer is in the range of 6 to 15 nm, the light transmittance is higher and the sheet resistance is suppressed compared to the samples outside this numerical range. It was confirmed that

  From the above results, by setting the calcium-containing layer and the conductive layer to the optimum film thickness, the calcium (Ca) atoms in the calcium-containing layer and the silver (Ag) atoms in the conductive layer are more likely to interact with each other. It is considered that a transparent electrode can be obtained in which both the improvement of the property and the improvement of the light transmittance are achieved.

  Further, when comparing each transparent electrode of Sample 117 and Sample 138, that is, each transparent electrode that is different only in having an optical adjustment layer on the conductive layer, the transparency of Sample 138 having an optical adjustment layer on the conductive layer is compared. It was confirmed that the electrode had higher light transmittance and suppressed sheet resistance.

  The above results were the same whether the transparent substrate was a polyethylene terephthalate (PET) substrate or a polyethylene naphthalate (PEN) substrate.

<Evaluation 2 of each sample of Example 1>
5 to 10 show secondary electron images (SEM image magnification: 100,000 times) of the transparent electrodes of the samples 101, 111, 112, 124, 124 ′, and 124 ″ by a scanning electron microscope.

<Evaluation result 2 of Example 1>
As shown in FIGS. 5 to 10, when comparing the transparent electrodes of the samples 101, 111, 112, 124, 124 ′, 124 ″, as described below, the conductive layer made of silver by the layer configuration of the transparent electrodes It was clear that the film formation states were different.

  That is, as shown in FIGS. 5 to 7, each of the transparent electrodes of the samples 101, 111, and 112 of the comparative example having no calcium-containing layer between the transparent substrate and the conductive layer is silver constituting the conductive layer. The continuity of the (white display portion in the figure) is low, and the portion not covered with the conductive layer (black display portion in the figure) is conspicuous.

  On the other hand, as shown in FIGS. 8 to 10, each transparent electrode of the samples 124, 124 ′, 124 ″ of the present invention having a calcium-containing layer between the transparent substrate and the conductive layer constitutes a conductive layer. Therefore, it was confirmed that a conductive layer having a stable film quality was formed with a uniform thickness even though it was thin.

  In particular, when the transparent electrodes of samples 124, 124 ′, and 124 ″ having the same layer structure and different only the thickness of the calcium-containing layer are compared, the samples 124 and 124 ′ having a calcium-containing layer thickness of 2.0 nm or less are compared. Each transparent electrode has almost no part which is not coat | covered with silver, and it was confirmed that the continuity of the silver which comprises an electroconductive layer is high.

<Evaluation 3 of each sample of Example 1>
FIGS. 11 to 14 show SEM images after the transparent electrodes of samples 124, 124 ′, and 124 ″ are stored for 300 hours under a high temperature environment (temperature of 85 ° C., drying conditions).

<Evaluation result 3 of Example 1>
As shown in FIG. 11 to FIG. 14, when comparing each transparent electrode of the samples 124, 124 ′, 124 ″ after high-temperature storage, as described below, the conductive layer made of silver depends on the thickness of the calcium-containing layer. 13 shows a part of the transparent electrode of the sample 124 in which the thickness of the calcium-containing layer is 1.0 nm.

  That is, as shown in FIGS. 11 to 12, in the transparent electrodes of the samples 124 and 124 ′ having a calcium-containing layer thickness of 2.0 nm or less, fine defects at the time of film formation almost spread after storage at high temperature. It was confirmed that the continuity of the silver constituting the conductive layer was high. However, as shown in FIG. 13, in the transparent electrode of the sample 124, a part of the fine defect portion spread at the time of film formation was confirmed.

  On the other hand, as shown in FIG. 14, the transparent electrode of the sample 124 ″ with the calcium-containing layer having a thickness of 3.0 nm has a defect portion spread during film formation after high temperature storage, and the continuity of the conductive layer is low. The portion not covered with the conductive layer (black display portion in the figure) is conspicuous.

  From the above evaluation results 2 and 3, by setting the calcium-containing layer to the optimum film thickness, the calcium (Ca) atoms of the calcium-containing layer and the silver (Ag) atoms of the conductive layer are more likely to interact and are thin. However, it is considered that a conductive layer having a uniform film thickness and a stable film quality is formed.

  Hereinafter, the present invention will be specifically described based on Example 2, but the present invention is not limited to Example 2 below.

<< Production of bottom emission type organic EL elements >>
The bottom emission type organic EL elements of Samples 201 to 237 were prepared so that the area of the light emitting region was 4.5 cm × 4.5 cm. The manufacturing procedure will be described with reference to FIG. 15 and Table 2 below. In addition, in the following Table 2, the structure of the transparent electrode used for the organic EL element of the samples 201-237 was shown.

[Preparation of transparent electrode 10]
First, in the samples 201 to 237, first, each transparent electrode having the configuration shown in Table 1 was formed. The procedure for forming the transparent electrode of each structure was performed in the same manner as in the production of the transparent electrode having the corresponding structure in Example 1.

[Preparation of Light-Emitting Functional Layer 3]
(Hole transport / injection layer 51)
The heating boat containing the organic material A (α-NPD) having the structural formula shown above as the hole transporting injection material is heated and energized, and serves as both the hole injection layer and the hole transporting layer made of α-NPD. The hole transport / injection layer 51 was formed on the conductive layer 2 of the transparent electrode 10. At this time, the deposition rate was 0.1 nm / second to 0.2 nm / second, and the film thickness was 20 nm.

(Light emitting layer 52)
Next, the heating boat containing the host material H4 represented by the following structural formula and the heating boat containing the phosphorescent compound Ir-4 represented by the following structural formula were respectively energized independently, so that the host material H4 and the phosphorescent light emission were emitted. The light emitting layer 52 made of the photosensitive compound Ir-4 was formed on the hole transport / injection layer 51. 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 of the light emitting layer 52 was 30 nm.

(Hole blocking layer 53)
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 53 made of BAlq on the light emitting layer 52. At this time, the deposition rate was 0.1 nm / second to 0.2 nm / second, and the film thickness was 10 nm.

(Electron transport / injection layer 54)
After that, as the electron transport / injection material, the heating boat containing the organic material B shown in the structural formula and the heating boat containing potassium fluoride were energized independently, respectively, and the organic material B and potassium fluoride were supplied. An electron transport / injection layer 54 serving as both an electron injection layer and an electron transport layer, formed of At this time, the energization of the heating boat was adjusted so that the deposition rate was organic material B: potassium fluoride = 75: 25. The film thickness was 30 nm.

[Preparation of counter electrode 5]
Next, the transparent substrate 11 on which the light emitting functional layer 3 is formed is transferred into a vacuum chamber of a vacuum vapor deposition apparatus, the pressure inside the vacuum chamber is reduced to 4 × 10 ⁻⁴ Pa, and then the aluminum attached in the vacuum chamber is made. The heated boat was energized and heated. Thus, the counter electrode 5 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 is used as a cathode.

(Element sealing)
Thereafter, the organic EL element 50 is covered with a sealing material (not shown) made of a glass substrate having a thickness of 300 μm, and the adhesive is interposed between the sealing material and the transparent substrate 11 so as to surround the organic EL element 50. (Sealing material) was filled. As the adhesive, an epoxy photocurable adhesive (Luxtrac LC0629B manufactured by Toagosei Co., Ltd.) was used. The adhesive filled between the sealing material and the transparent substrate 11 was irradiated with UV light from the side of the sealing material made of a glass substrate, and the adhesive was cured to seal the organic EL element 50.

  In the formation of the organic EL element 50, a vapor deposition mask is used for forming each layer, the central 4.5 cm × 4.5 cm of the 5 cm × 5 cm transparent substrate 11 is used as the light emitting region, and the width of the entire circumference of the light emitting region is wide. A non-light emitting area of 0.25 cm was provided. Further, the conductive layer 2 of the transparent electrode 10 serving as the anode and the counter electrode 5 serving as the cathode are insulated from each other by the hole transport / injection layer 51 to the electron transport / injection layer 54, and the peripheral edge of the transparent substrate 11. The terminal part was formed in the shape pulled out.

  As described above, each light-emitting panel of the organic EL element 50 of Samples 201 to 237 in which the organic EL element 50 was sealed with the sealing material and the adhesive was obtained. In each of these light emitting panels, each color of emitted light h generated in the light emitting layer 52 is extracted from the transparent substrate 11 side.

<Evaluation of each sample of Example 2>
With respect to the organic EL element 50 produced in Samples 201 to 237, (1) driving voltage (V), (2) chromaticity difference (Δxy), and (3) high temperature storage stability (ΔV) were measured. The results are also shown in Table 2 below.

(1) The drive voltage was measured by measuring the voltage when the front luminance on the transparent substrate 11 side of each organic EL element of each of the samples 201 to 237 was 1000 cd / m ² as the drive voltage. A spectral radiance meter CS-2000 (manufactured by Konica Minolta Sensing) was used for the measurement of luminance. A smaller value of the obtained drive voltage indicates a more favorable result.
(2) The color change was measured by applying a current of ^2.5 mA / cm ² to each organic EL element of each of the samples 201 to 237, and measuring the chromaticity in the CIE 1931 color system from positions at different angles. 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 substrate 11 side and each position of 45 ° in the vertical horizontal (up, down, left and right) directions. The difference in chromaticity measured at different angles is shown in Table 2 below as color change (Δxy). The color change represents the viewing angle characteristic of chromaticity, and the smaller the value, the better the result.
(3) In the measurement of high temperature storage stability, the sheet resistance after each organic EL element of Samples 201 to 237 was stored for 300 hours under a high temperature environment (temperature of 85 ° C., drying conditions) was measured. And the resistance increase rate of the sheet resistance after the preservation | save with respect to the sheet resistance before a preservation | save was computed as high temperature preservability ((DELTA) V). The smaller the value obtained, the better the result. The results are also shown in Table 2 below.

  Table 2 below shows the configurations of the samples 201 to 237 and the measurement results of the drive voltage (V), the chromaticity difference (Δxy), and the high temperature storage stability (ΔV).

<Evaluation results of Example 2>
As is apparent from Table 2, each of the organic EL elements of Samples 201 to 203 and Samples 213 to 215, that is, different only in that a transparent electrode having a calcium-containing layer was provided between the transparent substrate and the conductive layer. When the organic EL elements were compared, each of the organic EL elements of Comparative Examples 201 to 203 having no calcium-containing layer did not emit light.
This was also confirmed from a comparison of the evaluation results of the organic EL elements of Samples 204 to 210 and Samples 216 to 222, which differed only in having a transparent electrode having a calcium-containing layer.

  Here, in each organic EL element of the samples 201 to 212 of the comparative example that does not have a calcium-containing layer between the transparent substrate and the conductive layer, the organic EL of the sample 212 having a base layer made of the organic material B Only the device was confirmed to emit light. However, when compared with the organic EL element of the sample 224 of the present invention, the organic EL element of the sample 212 differs only in the configuration having the calcium-containing layer, and sufficient results are not obtained in driving voltage, color change, and high-temperature storage stability. It was.

  In addition, each organic EL element of Samples 217 and 228 to 231 in which the film thickness of the calcium-containing layer of the present invention is 2 nm or less is compared with the organic EL element of Sample 212 of the comparative example. In addition, good results were obtained in high temperature storage stability. Furthermore, the organic EL elements of Samples 217 and 229 to 231 in which the film thickness of the calcium-containing layer was in the range of 0.1 to 2 nm gave better results in color change. In particular, in the organic EL elements of Samples 217, 230, and 231 in which the film thickness of the calcium-containing layer is in the range of 0.5 to 2 nm, better results were obtained with respect to driving voltage and color change.

  Moreover, each organic EL element of the samples 217 and 234 to 236 in which the film thickness of the conductive layer of the present invention is in the range of 6 to 20 nm is different from the organic EL element of the sample 212 of the comparative example as compared with the driving voltage and color change. And good results were obtained in high temperature storage stability. Furthermore, in each of the samples 217, 234, and 235 in which the film thickness of the conductive layer was in the range of 6 to 15 nm, better results were obtained in the color change.

  From the above, it was confirmed that the organic EL device using the transparent electrode having the configuration of the present invention was improved in performance.

  The present invention is not limited to the configuration described in the above-described embodiment, and various modifications and changes can be made without departing from the configuration of the present invention.

  DESCRIPTION OF SYMBOLS 10,20,30 ... Transparent electrode, 11 ... Transparent substrate, 1 ... Calcium containing layer, 2 ... Conductive layer, 21 ... Underlayer, 31 ... Optical adjustment layer, 40, 50 ... Organic EL element, 3 ... Light emission functional layer 3a, 52 ... light emitting layer, 51 ... hole transport / injection layer, 53 ... hole blocking layer, 54 ... electron transport / injection layer

Claims (9)

A transparent substrate;
A conductive layer mainly composed of silver;
Between the transparent substrate and the conductive layer , having a calcium layer made of metallic calcium (Ca) provided so as to be in contact with the conductive layer ,
The film thickness ratio of the conductive layer and the calcium layer is in the range of 10: 1 to 30: 1 ,
A transparent electrode in which the conductive layer constitutes an electrode closest to the transparent substrate . The transparent electrode according to claim 1, wherein the conductive layer has a thickness of 10 to 20 nm. Between the transparent substrate and the calcium layer, having an optical adjustment layer,
The optical adjustment layer, a transparent electrode according to claim 1 or 2 is composed of a metal oxide or metal sulfide. The calcium layer is in contact with the optical adjustment layer
The transparent electrode according to claim 3 . The transparent electrode according to claim 1, wherein the calcium layer has a thickness of 2 nm or less. The transparent electrode according to any one of claims 1 to 5 , wherein the conductive layer and the calcium layer are sandwiched by an optical adjustment layer. Electronic device having a transparent electrode according to claim 1-6. The electronic device is an organic electroluminescent element
The electronic device according to claim 7 . The transparent electrode according to any one of claims 1 to 6 ,
A light emitting functional layer provided on the transparent electrode,
A counter electrode provided in a state of sandwiching the light emitting functional layer between the transparent electrode,
The electronic device according to claim 7 , wherein the light emitting functional layer is provided at a position where the conductive layer is sandwiched between the light emitting functional layer and the calcium layer .