TWI533461B - Transparent electrode substrate, method for producing the same, electronic device and solar cell having the transparent electrode substrate - Google Patents

Description

Transparent electrode substrate, method of manufacturing the same, electronic device having the same, and solar cell

The present invention relates to a transparent electrode substrate, a method of manufacturing the same, and a solar cell having the transparent electrode substrate. More specifically, the present invention relates to a transparent electrode substrate having a high light transmittance, a method of manufacturing the same, an electronic device having the transparent electrode substrate, and a solar cell.

In recent years, transparent electrode substrates having a transparent conductive layer have been actively explored in organic electroluminescence (organic EL), various solar cells including organic solar cells, touch panels, mobile phones, and electronic paper.

In general, a transparent electrode substrate in which a transparent conductive layer is formed on a substrate such as a glass substrate is used as an electrode of an electronic device such as a solar cell or an organic EL. However, a transparent electrode substrate using a metal oxide layer such as tin-doped indium oxide (hereinafter referred to as ITO) as a transparent conductive layer has a high volume resistivity of ITO itself except that the surface resistivity is not low. . A transparent conductive substrate such as an organic EL, various solar cells, a touch panel, a mobile phone, or an electronic paper is required to have a transparent conductive substrate having a surface resistivity of, for example, about 5 Ω/□.

For such a request, a transparent electrode substrate using a metal material layer having a volume resistivity lower than that of a transparent conductive layer as an auxiliary electrode has been considered.

For example, Patent Document 1 discloses a substrate having a transparent conductive film formed by sequentially laminating a transparent oxide layer, a metal layer, and a transparent oxide layer on a substrate. However, in such a configuration, the light transmittance is low, and it is not practical as a transparent electrode substrate of a thin film device. Further, since the metal layer is laminated on the entire surface of the transparent oxide layer, there is a problem that the durability of the thin film device using the substrate with the transparent conductive film is a problem due to deterioration of the metal layer.

Further, Patent Document 2 discloses an electroluminescence panel comprising: an elongated or mesh-shaped auxiliary electrode layer containing a metal formed on a first electrode of ITO formed on a substrate; The light-emitting layer of the light-emitting region and the second electrode formed thereon are defined.

Further, Patent Document 3 discloses an organic thin film solar cell including a transparent substrate, a mesh electrode including a metal film laminated on the transparent substrate in a different order, and a transparent electrode, and the mesh electrode and the transparent electrode. The photoelectric conversion layer formed on the upper surface and the counter electrode formed on the photoelectric conversion layer.

However, in such a configuration, there is a possibility of causing problems such as deterioration due to metal corrosion.

Patent Document 4 discloses a transparent conductive film which has a base metal or a conductive metal mesh layer containing a base metal on at least one side surface of a transparent base material sheet, and a transparent conductive layer including a conductive polymer layer. Conductive layer; Patent Document 5 discloses a transparent conductive film having a transparent conductive film having a mesh-like conductive layer formed of at least one metal on a transparent support, and having a migration on the conductive layer A transparent conductive layer for a preventive agent, and an electrode for a dye-sensitized solar cell, which is an electrode for a dye-sensitized solar cell comprising a transparent conductive film formed on a substrate, is disclosed in Patent Document 6 An electric conductor having a lower resistance value than the transparent conductive film is disposed between the transparent conductive film and the transparent conductive film.

However, as an electrode of an electronic device such as a solar cell or an organic EL device, transparency, conductivity, and durability are further improved in the transparent electrode substrate.

Prior technical literature Patent literature

Patent Document 1 Japanese Special Kaiping 10-241464

Patent Document 2 Japanese Special Open 2008-103305

Patent Document 3 Japanese Special Open 2010-157681

Patent Document 4 Japanese Special Open 2009-081104

Patent Document 5 Japanese Special Open 2009-146678

Patent Document 6 Japanese Special Open 2004-296669

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a transparent electrode substrate having high light transmittance and excellent electrical conductivity, a method of manufacturing the same, and a transparent electrode substrate. Electronic device.

In order to solve the problems as described above, the inventors of the present invention have found that the above problems can be solved by creating a layer structure as follows, and thus the present invention has been completed.

That is, the present invention provides the following:

(1) A transparent electrode substrate comprising a transparent conductive layer in which a conductive metal mesh layer is laminated on one side of a transparent substrate.

(2) The transparent electrode substrate according to (1) above, wherein the transparent conductive layer is a layer composed of a metal oxide.

(3) The transparent electrode substrate according to (1) above, wherein the conductive metal mesh layer has a thickness of from 1 to 100 nm.

(4) The transparent electrode substrate according to (1) above, wherein an opening ratio of the opening of the conductive metal mesh layer is 75% or more.

(5) The transparent electrode substrate according to (1) above, wherein the transparent conductive layer is a layer containing indium oxide as a main component.

(6) The transparent electrode substrate according to (1) above, wherein the conductive metal mesh layer is a layer composed of at least one selected from the group consisting of gold, silver, copper, platinum, aluminum, nickel, and chromium.

(7) A method of producing a transparent electrode substrate, wherein a first transparent conductive layer is formed on one side surface of a transparent substrate, a conductive metal layer is formed on the transparent conductive layer, and the conductive metal is patterned by photoresist A conductive metal mesh layer is formed in a layer, and a second transparent conductive layer is formed on the surface of the metal mesh layer, and the conductive metal mesh layer is coated through the transparent conductive layer.

(8) The method for producing a transparent electrode substrate according to (7) above, wherein the first transparent conductive layer formed on one side surface of the transparent substrate has a thickness of 10 to 1000 nm.

(9) The method for producing a transparent electrode substrate according to (7) or (8) above, wherein the second transparent conductive layer formed on the surface of the metal mesh layer has a thickness of 1 to 200 nm.

(10) An electronic device comprising the transparent electrode substrate according to any one of the above (1) to (6).

(11) A solar cell comprising the transparent electrode substrate according to any one of the above (1) to (6).

The transparent electrode substrate of the present invention maintains light transmittance at a high level, and has a low surface resistivity and excellent electrical conductivity. Further, in the solar cell using the transparent electrode substrate of the present invention, high photoelectric conversion efficiency can be obtained.

[Formation for implementing the invention]

Hereinafter, the present invention will be described in detail.

<Transparent electrode substrate>

The transparent electrode substrate of the present invention comprises a transparent conductive layer in which a conductive metal mesh layer is laminated on one side of a transparent substrate.

Hereinafter, the material of the transparent electrode substrate of the present invention will be described.

[Transparent substrate]

In the transparent substrate, from the viewpoint of transparency, the total light transmittance is preferably 85% or more. As such a transparent substrate, glass (plate), a plastic film, or the like is generally used.

For example, as a kind of plastic film, polyethylene terephthalate, polyethylene naphthalate, triethylene sulfonate, syndiotactic polystyrene, poly benzene may be exemplified. A plastic film such as thioether, polycarbonate, polyarylate, polyfluorene, polyester oxime, polyether quinone, or cyclic polyolefin. Among them, as a superior mechanical strength, durability, transparency, versatility, etc., it is preferable to contain glass (plate) or polyethylene terephthalate, polyethylene naphthalate, poly aromatic A plastic film such as an ester. The thickness of the substrate is preferably from 3 μm to 5 mm, more preferably from 5 μm to 3 mm, particularly preferably from 10 μm to 1 mm, from the viewpoint of equalizing mechanical strength, durability, and transparency.

[Transparent Conductive Layer]

The material of the transparent conductive layer is not particularly limited, and examples thereof include conductive metal oxides such as oxides such as indium, tin, zinc, and gallium, and composite oxides of these elements.

More specifically, tin-doped indium oxide (ITO), yttrium oxide (IrO ₂ ), indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), fluorine-doped tin oxide (FTO), Indium oxide-zinc oxide (IZO), zinc oxide (ZnO), gallium-doped zinc oxide (GZO), aluminum-doped zinc oxide (AZO), molybdenum oxide (MoO ₃ ), titanium oxide (TiO ₂ ), and the like.

The thickness of the transparent conductive layer is preferably from 20 to 1200 nm, further preferably from 30 to 1000 nm, and particularly preferably from 35 to 700 nm.

The method of forming the transparent conductive layer on the transparent substrate is not particularly limited, and a conventional method can be used. For example, PVD (physical vapor deposition) such as vacuum deposition, sputtering, ion plating, or dry process such as thermal CVD, atomic layer deposition (ALD), or the like can be used or wet. The transparent conductive layer material is formed by a conventional method such as a jet method or a screen printing method, and is appropriately selected depending on the material of the transparent substrate or the transparent conductive layer.

The surface resistivity of the transparent conductive layer is preferably 50 Ω/□ or less, and more preferably 10 Ω/□ or less.

When the surface resistivity exceeds 50 Ω/□, for example, when a transparent electrode substrate is applied to a thin film solar cell, since the internal resistance is large, the photoelectric conversion efficiency is not preferable.

In the transparent electrode substrate of the present invention, the transparent conductive layer is laminated on one side surface of the transparent substrate by a shape in which a conductive metal mesh layer is buried.

The transparent conductive layer in which the conductive metal mesh layer is embedded is formed on one side of the transparent substrate, and the conductive metal mesh layer is preferably buried on the side opposite to the transparent substrate side and the opposite side of the transparent conductive layer.

That is, the conductive metal mesh layer has a thickness of 100% as a whole of the transparent conductive layer, and is preferably embedded in a range of 50 to 99% of the transparent substrate side from the entire thickness of the transparent conductive layer.

When the position where the conductive metal mesh layer is buried is in this range, the conductivity is good. This is considered to be because the conductive metal mesh layer having excellent conductivity is buried on the surface opposite to the transparent substrate of the transparent conductive layer, whereby the surface resistivity of the transparent conductive layer can be lowered and the conductivity can be improved.

[Electrically conductive metal mesh layer]

In the transparent electrode substrate of the present invention, the conductive metal mesh layer is made of a metal or an alloy and is embedded in a transparent conductive layer formed on one side of the transparent substrate. As the conductive metal mesh layer, a layer of a fine mesh structure due to a metal gate pattern can be exemplified.

The conductive metal mesh layer has an opening penetrating through the thickness direction.

The aperture ratio of the opening portion is preferably 75% or more, more preferably 80% or more, and still more preferably 90% or more from the viewpoint of transparency. The aperture ratio is obtained as follows:

The aperture ratio (%) = [area of the opening / (area of the conductive metal mesh layer + area of the opening)] × 100%.

The shape of the conductive metal mesh layer preferably has an opening, but is not particularly limited. For example, a periodic mesh shape such as a square, a rectangle, or a hexagon as shown in FIG. 2 may be mentioned.

The distance between the openings is preferably from 0.1 to 10 mm, more preferably from 0.5 to 5 mm. When the distance between the openings is less than 0.1 mm, the transparency is lowered. When it exceeds 10 mm, it is difficult to obtain an effect of improving the conductivity.

The line width of the conductive metal mesh layer is preferably from 10 nm to 1000 μm, more preferably from 20 nm to 500 μm. When the line width exceeds 1000 μm, the transparency is lowered because the aperture ratio is lowered, and when it is less than 10 nm, it is difficult to obtain an effect of improving conductivity.

The thickness of the conductive metal mesh layer is preferably from 1 to 100 nm, more preferably from about 2 to 50 nm. When the thickness is 1 nm or more, the conductivity can be maintained, and when the thickness is 100 nm or less, the overall thickness can be kept thin, and waste of materials can be saved.

As a material for forming the conductive metal mesh layer, a metal or an alloy can be exemplified. For example: gold, silver, copper, aluminum, titanium, chromium, iron, cobalt, nickel, zinc, tin, antimony, indium, tungsten, molybdenum, platinum, rhodium, ruthenium, osmium, iridium, tungsten, magnesium, etc. The metal of the body is an alloy or the like mainly composed of at least one of metals including such groups. Among these, from the viewpoint of corrosion resistance and high conductivity, metals such as gold, silver, copper, platinum, aluminum, titanium, nickel, and chromium are preferable, and gold, silver, copper, platinum, and aluminum are more preferable. , nickel and chromium.

As the alloy, stainless steel, nickel-chromium, Inconel (trade name), bronze, phosphor bronze, brass, hard aluminum, white copper, invar, and monel alloy can be appropriately selected ( Monel), a metal phosphorus compound such as a nickel phosphorus alloy; a metal boron compound such as nickel boron; a metal nitride such as titanium nitride. In particular, copper-based alloys, nickel-based alloys, cobalt-based alloys, chromium-based alloys, and aluminum-based alloys have superior electrical conductivity and processability. Good is used.

The conductive metal mesh layer may be a single layer made of a metal or an alloy, or may have a multilayer structure in which a layer composed of at least two kinds of metals or alloys is laminated.

Next, a method of embedding a conductive metal mesh layer inside the transparent conductive layer provided on the transparent substrate will be described.

The method of embedding the conductive metal mesh layer is not particularly limited, and a conventional method can be appropriately selected and used according to the material of the conductive metal mesh layer and the mesh shape. For example, a method of attaching a preformed conductive metal mesh layer to a transparent conductive layer provided on a transparent substrate using an adhesive or a conductive paste or the like, and further forming a transparent conductive layer thereon may be exemplified; or A method of forming a conductive metal mesh layer on a transparent conductive layer provided on a transparent substrate by an inkjet method, a screen printing method, or the like, and further forming a transparent conductive layer thereon; and, otherwise, performing mesh processing A conductive metal layer (hereinafter, simply referred to as a conductive metal layer) is formed on a transparent conductive layer provided on a transparent substrate, and the conductive metal layer is processed into a mesh shape to form a conductive metal mesh layer. Further, a method of forming a transparent conductive layer thereon or the like.

Hereinafter, a method of forming a conductive metal mesh layer will be described.

First, a conductive metal layer is formed on the transparent conductive layer provided on the transparent substrate by the above method. The above method is appropriately selected in accordance with the material of the conductive metal layer.

Then, the conductive metal layer to be formed is processed into a mesh shape by various conventional mechanical treatments or chemical treatments such as a method of etching by photolithography and forming a mesh pattern, thereby forming a conductive metal mesh. Floor.

As described above, by forming the transparent conductive layer on the formed conductive metal mesh layer by the above method, it is possible to obtain the form of the present invention in which the conductive metal mesh layer is embedded in the transparent conductive layer. Transparent electrode substrate.

In the present invention, since the conductive metal mesh layer is embedded in the transparent conductive layer, the transparency of the transparent electrode substrate is compared with a structure in which a conductive metal layer which is not subjected to mesh processing is provided between the transparent conductive layers. Sex will increase. Further, a transparent electrode substrate further having a structure in which a transparent conductive layer is directly provided on a transparent substrate as in a conventional one, or a transparent electrode substrate on which a conductive metal mesh layer is directly provided on a transparent substrate and a transparent conductive layer is provided thereon (In other words, the transparent electrode substrate in which the transparent conductive layer of the conductive metal mesh layer is not embedded is provided), the surface resistivity is lower, and the conductivity is superior.

[Method of Manufacturing Transparent Electrode Substrate]

Next, a method of manufacturing the transparent electrode substrate of the present invention will be described.

The method for producing the transparent electrode substrate of the present invention is as follows.

It has the following characteristics: first, a first transparent conductive layer is formed on one side of a transparent substrate, a conductive metal layer is formed on the first transparent conductive layer, and the conductive metal layer or the like is formed by a photoresist pattern. In the conductive metal mesh layer, a second transparent conductive layer is formed on a surface of the metal mesh layer, and the conductive metal mesh layer is covered by the second transparent conductive layer, and then a conductive metal mesh layer is buried in the transparent conductive layer. .

Here, in the photoresist pattern processing, the conductive metal layer is etched by photolithography, and a mesh pattern is formed in the conductive metal layer.

According to this method, the transparent electrode substrate of the present invention comprising the transparent conductive layer in which the conductive metal mesh layer is embedded in one side of the transparent substrate can be efficiently produced.

The material for forming the conductive metal layer may be the same as the material for forming the conductive metal mesh layer described above. As a method of forming the conductive metal layer, the transparent conductive material may be exemplified and formed. The method of the layer is the same, and it is suitably selected according to the material of a conductive metal layer. Specifically, for example, a material such as silver or copper, PVD (physical vapor deposition) such as vacuum evaporation, sputtering, ion plating, or CVD (chemical CVD, atomic layer deposition (ALD), etc.) is used. A conductive process such as a vapor phase vapor deposition method or a conventional method such as a wet process inkjet method or a screen printing method can form a conductive metal layer.

The material for forming the first transparent conductive layer and the second transparent conductive layer may be the same as the material for forming the transparent conductive layer described above.

The material of the first transparent conductive layer formed on one side of the transparent substrate and the second transparent conductive layer formed on the conductive metal mesh may be the same or different, but generally the same material is preferable. By.

The method of forming the first transparent conductive layer and the second transparent conductive layer can be appropriately selected in accordance with the material of the transparent conductive layer, for example, in the same manner as the method of forming the transparent conductive layer described above.

Further, the thickness of the second transparent conductive layer which is usually formed on the conductive metal mesh layer is preferably a thickness of the first transparent conductive layer formed on one side of the transparent substrate.

The thickness of the first transparent conductive layer formed on one side of the transparent substrate is usually from 10 to 1000 nm, preferably from 10 to 500 nm, particularly preferably from 30 to 300 nm, from the viewpoints of transparency and conductivity.

The thickness of the second transparent conductive layer formed on the conductive metal mesh is usually from 1 to 200 nm, preferably from 10 to 200 nm, further preferably from 20 to 100 nm, and particularly preferably from 25 to 50 nm. Since the transparent electrode substrate of the present invention has excellent transparency and conductivity, it can be used as an electrode for various electronic devices.

<electronic device>

The electronic device of the present invention is characterized by having the above-described transparent electrode substrate of the present invention.

As an electronic device to which the transparent electrode substrate of the present invention can be applied, an organic device such as a transistor, a memory, an organic EL, an organic thin film solar cell, or the like; a liquid crystal display; an electronic paper; a thin film transistor; an electrochromic display; Learning light-emitting device; touch panel; display; photoelectric conversion device; thermoelectric conversion device; piezoelectric conversion device;

<solar battery>

The solar cell of the present invention is characterized by having the above-described transparent electrode substrate of the present invention.

Examples of the solar cell to which the transparent electrode substrate of the present invention can be applied include an organic thin film solar cell, a thin film germanium solar cell, a hybrid solar cell, a multi-junction solar cell, a spherical germanium solar cell, and an electric field effect solar cell. Various solar cells such as batteries and dye-sensitized solar cells. Among them, the solar cell of the present invention is preferably an organic thin film solar cell having the above-described transparent electrode substrate of the present invention.

Here, an organic thin film solar cell will be described as an example.

Fig. 1 is a cross-sectional view showing an example of a layer of an organic thin film solar cell constituting an example of a solar cell of the present invention. In the first embodiment, a 1st transparent substrate, a 2nd first transparent conductive layer, a 3rd conductive metal mesh layer, a 4th second transparent conductive layer, a 5th photoelectric conversion layer, a 6th electrode, and a 7th substrate are used. Layers, 8 series of transparent conductive layers in which a conductive metal mesh layer is embedded, 9 series of transparent electrode substrates of the present invention, and 10 series organic thin film solar cells.

[Photoelectric conversion layer]

The photoelectric conversion layer (5 in the first drawing) is a layer for photoelectric conversion, and is preferably from the viewpoints of cost reduction, flexibility, ease of formation, high light absorption coefficient, light weight, impact resistance, and the like of the raw material. For organic semiconductors.

The photoelectric conversion layer may be formed of a single layer or a plurality of layers. In the case of a single layer, the photoelectric conversion layer is usually formed of a natural semiconductor (i-type semiconductor).

Further, in the case of a plurality of layers, it is a laminate of (p-type semiconductor layer/n-type semiconductor layer) or (p-type semiconductor layer/negative semiconductor layer/n-type semiconductor layer).

The thickness of the photoelectric conversion layer is generally preferably from 30 nm to 2 μm, particularly preferably from 40 nm to 300 nm, from the viewpoint of the case of a single layer or a plurality of layers, and the difference between the conductivity and the diffusion distance of the excitons.

Hereinafter, the organic semiconductor used in the photoelectric conversion layer will be described.

(1) Intrinsic semiconductor

As a material of the intrinsic semiconductor, at least one of a fullerene, a fullerene derivative, a semiconducting carbon nanotube (CNT), and a CNT compound can be mixed so that the obtained semiconductor becomes an intrinsic semiconductor. A first material and a mixture of a second material comprising a polyphenylene vinylene (PPV) derivative or a polythiophene polymer material.

As the fullerene derivative, for example, [6,6]-phenyl-C ₆₁ -butyric acid methyl ester (PCBM) or the like can be used, and in addition, a fullerene or a base can be used. A fullerene compound such as a metal or an alkaline earth metal. Further, as the CNT, a carbon nanotube or the like in which fullerenes or metal-filled fullerenes are contained can be used. Further, a CNT compound or the like in which various molecules are added to the side wall or the tip end of the CNT can also be used.

As a derivative of polystyrene, it is possible to use poly[2-methoxy-5-(2'-ethylcyclohexyloxy)-p-vinylene] (MEH-PPV) or the like; as a polythiophene For the polymer material, poly(3-alkylthiophene) such as poly-3-hexylthiophene (P3HT), dioctylfluorene-bithiophene copolymer (F8T2), or the like can be used.

As a particularly preferred semiconductor, a mixture of PCBM and P3HT can be exemplified by mixing a mass ratio of 1:0.3 to 1:4.

(2) p-type semiconductor

Examples of the material of the p-type semiconductor include polyalkylthiophene and derivatives thereof, polyphenylene and derivatives thereof, polyphenylene ethylene and derivatives thereof, polydecane and derivatives thereof, and porphyrin derivatives. Anthraquinone derivatives, organometallic polymers, and the like. Among them, polyalkylthiophene and derivatives thereof are preferred. In addition, a mixture of organic materials such as this may also be used. As the conductive polymer compound, poly(3,4)-ethylenedioxythiophene/polystyrene sulfonate (PEDOT:PSS) can be preferably used.

(3) n-type semiconductor

As a material of the n-type semiconductor, a fullerene derivative is particularly preferred. For example, as the fullerene derivative, [6,6]-phenyl-C ₆₁ -butyric acid methyl ester (PCBM) or the like can be used.

As a method of forming the photoelectric conversion layer 5, a dry procedure such as a vacuum deposition method or a sputtering method, or various coating procedures such as dip coating, spin coating, spray coating, and bar coating are appropriately selected.

[electrode]

In comparison with the material (for example, the ITO electrode) which becomes the transparent conductive layer of the counter electrode, the material of the electrode (in FIG. 1 and 6) preferably has a large difference in work function. For example, in addition to metals, metal oxides or alloys of silver, aluminum, platinum, gold, rhodium, chromium, zinc oxide, etc., there may be a composite with the above metals, metal oxides or alloys.

The thickness of the electrode is preferably from 20 nm to 1 μm, particularly preferably from 30 nm to 100 nm.

As a method of forming the electrode 6 on the photoelectric conversion layer 5, PVD (physical vapor deposition) such as vacuum vapor deposition, sputtering, ion plating, or the like can be exemplified, and the material (work function, etc.) of the counter electrode is used. Appropriate choice.

[Substrate layer]

As a base material layer (7 of FIG. 1), a glass (plate) or a plastic film is generally exemplified, and it is suitably selected according to the use of an electronic device. For example, as the plastic film, polyethylene terephthalate, polyethylene naphthalate, tetraethyl cellulose, syndiotactic polystyrene, polyphenylene sulfide, polycarbonate can be exemplified. The film of polyarylate, polyfluorene, polyester oxime, polyether quinone, cyclic polyolefin or the like is preferably one having superior mechanical strength and durability.

[Examples]

Hereinafter, the present invention will be described in more detail by way of Reference Examples, Examples and Comparative Examples, but the invention is not limited thereto.

<Example 1> [Production of Transparent Electrode Substrate]

The substrate having the first transparent conductive layer laminated on one side of the transparent substrate is prepared by Geomatec Co., Ltd. under the product name "Flat ITO" (as a substrate, it is one of the thickness of 0.7 mm glass). A substrate having an ITO film of 250 nm on the side).

Next, on the ITO film of the substrate, silver (Ag) was formed into a film having a thickness of 5 nm by a vacuum deposition method under a reduced pressure of 1 × 10 ^-4 Pa or less to form a conductive metal layer.

Next, the conductive metal layer is subjected to a photoresist pattern treatment, and then an etching treatment (resist pattern processing) is performed to form a conductive metal mesh layer, and a square periodic mesh shape is formed (distance between openings is 1 mm, conductivity) The metal mesh layer has a line width of 30 μm, an aperture ratio of 94.1%, and a thickness of 5 nm.

Next, on the conductive metal mesh layer, ITO having a thickness of 30 nm was deposited by a sputtering method (spraying device manufactured by ULVAC, device name "i-sputter") under a reduced pressure of 1 × 10 ^-4 Pa or less. The film is formed as a second transparent conductive layer, and a transparent electrode substrate of the present invention in which a conductive metal mesh layer is embedded in a transparent conductive layer is obtained.

<Examples 2 to 4>

The transparent electrode substrate of the present invention was obtained in the same manner as in Example 1 except that the thickness of the conductive metal mesh layer (Ag) was changed to the thickness described in Table 1.

<Comparative Examples 1 to 4>

A transparent electrode substrate for comparison was produced in the same manner as in Example 1 except that the thickness of the conductive metal layer (Ag) was changed to the thickness described in Table 1, and the conductive metal was not subjected to the photoresist pattern treatment. That is, a comparative transparent electrode substrate in which a conductive metal layer not subjected to mesh processing is embedded in a transparent conductive layer is obtained.

<Comparative Example 5>

In the same manner as in Example 1, except that the conductive metal layer (Ag) was not formed, the thickness of the second transparent conductive layer was directly formed on the ITO film having a thickness of 250 nm as the first transparent conductive layer. The ITO film was used to prepare a transparent electrode substrate for comparison. That is, a comparative transparent electrode substrate having a structure in which only a transparent conductive layer is provided is obtained.

<Comparative Example 6>

A conductive metal layer having a thickness of 10 nm was formed on one side of a glass plate (manufactured by Kawamura K.K., Ltd., thickness: 3 mm) as a transparent substrate under the same conditions as in Example 2, and a conductive metal layer was formed. The photoresist pattern was processed to form a conductive metal mesh layer having an aperture ratio of 94.1%. Next, in the same manner as in Example 2, an ITO film was formed on the surface of the conductive metal mesh layer as a transparent conductive layer having a thickness of 150 nm to prepare a transparent electrode substrate for comparison. That is, a comparative transparent electrode substrate in which a transparent conductive layer in which a conductive metal mesh layer is not embedded is provided is prepared.

<Comparative Example 7>

In Comparative Example 6, a transparent electrode substrate for comparison was obtained in the same manner except that the thickness of the conductive metal layer (Ag) was changed to 20 nm. That is, a comparative transparent electrode substrate in which a transparent conductive layer in which a conductive metal mesh layer is not embedded is provided is prepared.

<Comparative Example 8>

In Comparative Example 6, a transparent electrode substrate for comparison was obtained in the same manner except that the thickness of the conductive metal layer (Ag) was changed to 30 nm. That is, a comparative transparent electrode substrate in which a transparent conductive layer in which a conductive metal mesh layer is not embedded is provided is prepared.

<Comparative Example 9>

In Comparative Example 6, a transparent electrode substrate for comparison was obtained in the same manner except that the thickness of the conductive metal layer (Ag) was changed to 50 nm. That is, a comparative transparent electrode substrate in which a transparent conductive layer in which a conductive metal mesh layer is not embedded is provided is prepared.

<Comparative Example 10>

In Comparative Example 6, a conductive metal mesh layer (Ag) was not formed, and an ITO film as a transparent conductive layer having a thickness of 150 nm was directly formed on the transparent substrate to obtain a transparent electrode substrate for comparison. That is, a comparative transparent electrode substrate having a structure in which a transparent conductive layer is provided only on a transparent substrate is obtained.

<Comparative Example 11>

A transparent electrode substrate for comparison was produced in the same manner as in Comparative Example 10 except that the thickness of the transparent conductive layer was 250 nm. That is, a comparative transparent electrode substrate having a structure in which only a transparent conductive layer is provided is obtained.

The respective characteristics of the transparent electrode substrate of the present invention obtained in Examples 1 to 4 and the comparative transparent electrode substrate obtained in Comparative Examples 1 to 11 are summarized in Table 1.

The physical properties of the materials described in Table 1 and the characteristics of the transparent electrode substrate were measured as follows.

(1) Thickness

The thickness of the transparent conductive layer, the conductive metal mesh layer, and the conductive metal layer was measured by a probe type surface shape measuring device (manufactured by ULVAC, product name "Dektak 150").

(2) Determination of surface resistivity

The surface resistivity of the surface of the transparent conductive layer of the obtained transparent electrode substrate was measured by a four-terminal method by a surface resistance measuring device (manufactured by Mitsubishi Chemical Corporation, product name "LORESTA GP MCP-T600").

(3) Light transmittance

The total light transmittance of the transparent electrode substrate was measured in accordance with JIS K7361-1 using a light transmittance measuring device [manufactured by Nippon Denshoku Industries Co., Ltd., product name "NDH-5000").

<Example 5> [Production of solar cells]

A solar cell was produced using the transparent electrode substrate of the present invention obtained in Example 3.

On the surface of the transparent conductive layer of the transparent electrode substrate, a polythiophene-based conductive polymer is first mixed with poly(3,4-epoxyethane thiophene) (PEDOT) and polystyrenesulfonic acid (PSS) (PEDOT:PSS). The product name "AI4083" manufactured by HC Stark Co., Ltd. was formed into a film having a thickness of 50 nm by a spin coating method. Next, a mixed solution of two organic materials of poly-3-hexylthiophene (P3HT) and [6,6]-phenyl-C ₆₁ -butyric acid methyl ester (PCBM) (Mohr ratio 1:1) was used. Film formation was carried out by a spin coating method to a thickness of 80 nm. The cathode was formed into a film by vacuum deposition to a thickness of 100 nm. Finally, the solar cell of the present invention was fabricated by sealing with a glass mask.

<Comparative Example 12>

Using the transparent electrode substrate of Comparative Example 5, a solar cell for comparison was obtained in the same manner as in Example 5.

[Evaluation of solar cells]

The solar cells of Example 5 and Comparative Example 12 had an effective area of 12 cm ² , and were irradiated with a simulated solar spectrum by a solar simulator (Wakom Electric Co., Ltd., WXS-50S-1.5). AM 1.5 (100 mW/cm ² )), photoelectric conversion efficiency was measured. The evaluation results of the solar cells are shown in Table 2.

From Tables 1 and 2, confirm the following:

(1) As shown in Examples 1 to 4 of Table 1, it was confirmed that the transparent electrode substrate of the present invention has high total light transmittance, excellent transparency, and also has a low surface resistivity value and is excellent. Electrical conductivity.

(2) On the other hand, the transparent electrode substrates of Comparative Examples 1 to 4 in which the conductive metal layer not subjected to the mesh processing is embedded in the transparent conductive layer have low total light transmittance and transparency is inferior to those of Examples 1 to 4. .

Further, in comparison with Examples 1 to 4, the transparent electrode substrates of Comparative Examples 5, 10, and 11 in which only the transparent conductive layer was provided on the transparent substrate had a high surface resistivity and poor conductivity.

Further, as shown in Comparative Examples 6 to 9, it was found that the direct conductive metal mesh was directly provided on the transparent substrate, and the conductive metal mesh layer was not embedded, and the total light transmittance was lower than that of Examples 1 to 3. In addition, the value of the surface resistivity is also high, and the transparency and conductivity are poor.

As shown by the results of Table 2, in comparison with the solar cell of Comparative Example 12, the solar cell of Example 5 using the transparent electrode substrate of the present invention can achieve high conversion efficiency and an efficiency of about 17%. By using the transparent electrode substrate having high transparency and low surface resistivity of the present invention, the photoelectric conversion efficiency is improved by the decrease in the internal resistance of the organic solar cell.

[Possibility of industrial use]

Since the transparent electrode substrate of the present invention has high transparency and low surface resistivity, it has excellent balance of transparency and conductivity. The transparent electrode substrate of the present invention can be used for solar cells such as organic thin film solar cells; organic devices such as transistors, memories, and organic EL; liquid crystal displays; electronic paper; thin film transistors; electrochromic displays; Touch panel; display; thermoelectric conversion device; piezoelectric conversion device; electronic device such as power storage device.

1. . . Transparent substrate

2. . . First transparent conductive layer

3. . . Conductive metal mesh layer

4. . . Second transparent conductive layer

5. . . Photoelectric conversion layer

6. . . electrode

7. . . Substrate

8. . . Transparent conductive layer

9. . . Transparent electrode substrate

10. . . Solar battery

Fig. 1 is a schematic view showing a cross section of an organic thin film solar cell which is an example of a solar cell using the transparent electrode substrate of the present invention.

Fig. 2 is a schematic view showing an example of the shape of a conductive metal mesh layer.

1. . . Transparent substrate

2. . . First transparent conductive layer

3. . . Conductive metal mesh layer

4. . . Second transparent conductive layer

5. . . Photoelectric conversion layer

6. . . electrode

7. . . Substrate

8. . . Transparent conductive layer

9. . . Transparent electrode substrate

10. . . Solar battery

Claims (12)

A transparent electrode substrate comprising a transparent conductive layer in which a conductive metal mesh layer is embedded on one side of a transparent substrate; and a conductive metal mesh in a case where the thickness of the entire transparent conductive layer is 100% The layer is embedded in a position ranging from 50 to 99% of the transparent substrate side of the entire thickness of the transparent conductive layer. The transparent electrode substrate of claim 1, wherein the transparent conductive layer is a layer composed of a metal oxide. The transparent electrode substrate of claim 1, wherein the conductive metal mesh layer has a thickness of 1 to 100 nm. The transparent electrode substrate according to claim 1, wherein an opening ratio of the opening of the conductive metal mesh layer is 75% or more. The transparent electrode substrate of claim 1, wherein the transparent conductive layer is a layer containing indium oxide as a main component. The transparent electrode substrate of claim 1, wherein the conductive metal mesh layer is a layer composed of at least one selected from the group consisting of gold, silver, copper, platinum, aluminum, nickel, and chromium. The transparent electrode substrate according to any one of claims 1 to 6, wherein a first transparent conductive layer is provided on one side of the transparent substrate, and a conductive metal mesh layer is provided on the first transparent conductive layer, and the layer is laminated The second transparent conductive layer in which the conductive metal mesh layer is embedded is formed. A method for manufacturing a transparent electrode substrate by using a transparent substrate Forming a first transparent conductive layer on one side surface, forming a conductive metal layer on the transparent conductive layer, patterning the conductive metal layer by a photoresist pattern to form a conductive metal mesh layer, and forming a second surface on the surface of the metal mesh layer The transparent conductive layer is coated with the conductive metal mesh layer via the transparent conductive layer. The method for producing a transparent electrode substrate according to claim 8, wherein the first transparent conductive layer formed on one side of the transparent substrate has a thickness of 10 to 1000 nm. The method for producing a transparent electrode substrate according to claim 8 or 9, wherein the thickness of the second transparent conductive layer formed on the surface of the metal mesh layer is 1 to 200 nm. An electronic device having the transparent electrode substrate according to any one of claims 1 to 7. A solar cell comprising the transparent electrode substrate according to any one of claims 1 to 7.