JP2012064645A - Organic photoelectric conversion element and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-weight and large-area organic photoelectric conversion element with high power generation efficiency and high durability by restraining the deterioration of a transparent electrode in the organic photoelectric conversion element caused by high-temperature treatment at around 150 degrees, improving high adhesiveness between a transparent plastic substrate and the transparent electrode, and by restraining the penetration of at least one of water vapor and oxygen of the transparent plastic substrate.SOLUTION: In the organic photoelectric conversion element in which at least the transparent plastic substrate, the transparent electrode, an organic semiconductor layer, and a counter electrode are layered in the order, the transparent electrode is formed by layering at least a transparent conductive thin-film layer, a metal thin-film layer and a transparent conductive thin-film layer in the order. In addition, a barrier layer is provided between the substrate and the transparent electrode.

Description

  The present invention relates to a solar cell, and more particularly to a solar cell having an insulating layer between a substrate and a transparent electrode.

  As a practical application study of a solar cell, a photoelectric conversion element is enlarged to obtain a large current. As the photoelectric conversion element becomes larger, the distance between the current extraction part and the photoelectric conversion element central part also becomes longer. In connection with this, the fall of the conversion efficiency by the surface resistance of a transparent electrode when a photoelectric conversion element is enlarged becomes a problem. In addition, when glass is used for the solar cell substrate, there is a drawback that the weight increases as the area increases.

  Conventionally, tin-doped indium oxide electrodes (ITO) have been used as transparent electrodes for organic photoelectric conversion elements. When ITO is crystallized, the conductivity is remarkably increased, the surface resistance is lowered, and the chemical stability is also improved. In order to crystallize ITO, it can be obtained by heating the substrate to a high temperature of usually 150 ° C. or higher and forming a vacuum film by a sputtering method or the like, or by heating to 150 ° C. or higher after forming the film at a low temperature. However, there are protrusions of about 50 nm at the maximum on the surface of the crystallized ITO.

By the way, the thickness of the photoelectric conversion layer of the organic photoelectric conversion element is about 100 nm, and if there are large protrusions on the electrode, the leakage current between the upper and lower electrodes increases, resulting in a decrease in conversion efficiency. Therefore, it is important to use an electrode having a small surface irregularity for the organic photoelectric conversion element.
An oxide-based transparent conductive thin film using amorphous ITO is known as a transparent electrode having a small surface unevenness. However, the organic photoelectric conversion element may be processed at a high temperature of about 150 ° C. during production in order to improve power generation efficiency. In this case, amorphous ITO crystallizes, and there is a possibility that irregularities are generated on the surface.

An amorphous oxide-based transparent conductive thin film having a crystallization temperature higher than 150 ° C. and high conductivity is known. Such a device includes an indium oxide electrode doped with zinc (IZO, Patent Document 1) and an indium oxide electrode doped with tungsten (IWO, Patent Document 2).
However, even if IZO or IWO is used, in order to obtain a low-resistance electrode, a film thickness of about 200 nm is usually required, but it is known that if the oxide-based transparent conductive thin film is thickened, cracks are likely to occur due to heating. It has been. In order to solve this drawback, it has been proposed to use a transparent thin film electrode in which both sides of a silver thin film are sandwiched between oxide-based transparent conductive thin films (Non-Patent Document 1).

However, when using a lightweight substrate such as a plastic film to reduce the weight of the solar cell, the adhesion between the inorganic oxide-based transparent conductive thin film and the substrate is poor, and the transparent conductive thin film may be peeled off. As a result of this, there is a concern that the photoelectric conversion efficiency is lowered and the durability is inferior.
Furthermore, a plastic film has a property of having higher transmittance of water vapor, oxygen, and the like than a glass substrate. Since it is known that the photoelectric conversion efficiency of the organic photoelectric conversion element decreases when the organic photoelectric conversion element comes into contact with water vapor or oxygen, such a property is not preferable when used as a substrate, and thus needs to be improved. There is sex.

JP 06-234565 A JP2004-6221

Journal of Vacuum Science and Technology A 28 (1) 41-47 (2010).

  The present invention has been made in view of the above-described conventional situation, and suppresses deterioration of the transparent electrode of the organic photoelectric conversion element by high-temperature treatment of about 150 degrees, improves the adhesion between the transparent plastic substrate and the transparent electrode, It is an object of the present invention to provide a light-weight and large-area organic photoelectric conversion element with high power generation efficiency and durability by suppressing permeation of at least one of water vapor and oxygen.

As a result of intensive studies by the present inventors, a transparent electrode having a low surface resistance, a transparent conductive thin film layer, a metal layer, and a transparent conductive thin film layer laminated in that order, and an inorganic compound between the transparent plastic substrate and the transparent electrode are used. It has been found that the above problem can be solved by providing a layer, and the present invention has been achieved.
That is, the present invention is as follows.
[1] In an organic photoelectric conversion element in which at least a transparent plastic substrate, a transparent electrode, an organic semiconductor layer, and a counter electrode are stacked in that order, the transparent electrode has at least a transparent conductive thin film layer, a metal thin film layer, and a transparent conductive thin film layer stacked in that order. An organic photoelectric conversion element, wherein a barrier layer is provided between the substrate and the transparent electrode.
[2] The organic photoelectric conversion device according to [1], wherein a metal oxide layer is provided between the transparent electrode and the organic semiconductor layer.
[3] The crystal transition temperature (Tc) of the transparent conductive thin film layer is 150 ° C. or more, and the specific resistance is 5 × 10 ⁻³ Ω / m or less, according to [1] or [2] Organic photoelectric conversion element.
[4] The organic photoelectric conversion element according to any one of [1] to [3], wherein the transparent electrode has a surface resistance of 10Ω / □ or less.
[5] The organic photoelectric conversion element according to any one of [1] to [4], wherein the transparent conductive thin film layer is indium oxide doped with zinc or indium oxide doped with tungsten.
[6] A solar cell module comprising the organic photoelectric conversion element according to any one of claims 1 to 5.

  According to the present invention, by suppressing deterioration of the transparent electrode of the organic photoelectric conversion element by high-temperature treatment of about 150 degrees, improving adhesion between the transparent plastic substrate and the transparent electrode, and suppressing permeation of at least one of water vapor and oxygen of the transparent plastic substrate, It has become possible to provide a light-weight, large-area organic photoelectric conversion element that is efficient and has improved durability, particularly PCE change rate and repeated bending resistance.

It is sectional drawing which shows typically the structure of the organic photoelectric conversion element as one Embodiment of this invention. It is sectional drawing which shows typically the structure of the solar cell as one Embodiment of this invention. It is sectional drawing which shows typically the structure of the solar cell module as one Embodiment of this invention.

Hereinafter, the present invention will be described in detail with reference to embodiments, examples, etc., but the present invention is not limited to the following embodiments, examples, etc., and can be arbitrarily set within the scope of the present invention. Can be changed and implemented.
<Organic photoelectric conversion element>
The organic photoelectric conversion device according to the present invention includes at least a transparent plastic substrate, a barrier layer, a transparent electrode, an organic semiconductor layer, and a counter electrode. Although FIG. 1 shows the organic photoelectric conversion element used for a general organic thin film solar cell, it is not necessarily restricted to this.

<Transparent plastic substrate>
The transparent plastic substrate is a support member that supports the organic photoelectric conversion element. The material for forming the substrate is transparent plastic, specifically, polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, fluororesin film, poly Organic materials such as vinyl chloride, polyethylene, polypropylene, cyclic polyolefin, cellulose, acetyl cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, poly (meth) acrylic resin, phenol resin, epoxy resin, polyarylate, polynorbornene Etc.

Among these, polyethylene terephthalate, polyethylene naphthalate, polyimide, and poly (meth) acrylic resin film are preferable from the viewpoint of easy formation of the organic photoelectric conversion element.
In addition, the material of a transparent plastic substrate may use 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Further, these plastic materials may contain reinforcing fibers such as carbon fibers and glass fibers to reinforce the mechanical strength.

As for the transparency of the transparent plastic substrate, the visible light transmittance defined by JIS R 3106 is 70% or more, preferably 80% or more.
The thickness of the transparent plastic substrate is not particularly limited as long as the transparency is satisfied, but from the viewpoint of ease of handling, it is usually 20 μm or more, preferably 50 μm or more, and usually 1000 μm or less, preferably 500 μm or less. More preferably, it is 200 μm or less.

<Barrier layer>
The organic photoelectric conversion element according to the present invention has a barrier layer between a transparent plastic substrate and a transparent electrode described later. By having the barrier layer, degassing from the transparent plastic substrate during film formation of the transparent conductive thin film layer described later is suppressed, the film formability of the transparent conductive thin film layer is improved, and the heat resistance of the transparent plastic substrate is Since plasma resistance arises, it is preferable.

At least one barrier layer may be formed on the surface of the transparent plastic substrate opposite to the transparent electrode. With this configuration, the barrier layer has an effect of suppressing the ingress of moisture and oxygen from the outside, suppresses deformation of the substrate due to stress during film formation, and has flexibility. This is preferable.
The material of the barrier layer is not particularly limited as long as it can form a dense film, and specifically, silicon oxide, silicon nitride, silicon carbide, aluminum oxide, aluminum nitride, indium oxide, oxide Examples thereof include transparent inorganic compounds such as tin and zinc oxide, or mixed compounds thereof. Among these, silicon oxide, silicon nitride and a mixture thereof, and aluminum oxide, aluminum nitride and a mixture thereof are preferable.

The thickness of the barrier layer is not particularly limited as long as the thickness is such that the transparency is not impaired, the gas barrier property is maintained, and the adhesion with the transparent plastic substrate is ensured, and usually 10 nm or more. , Preferably 20 nm or more, while usually 500 nm or less, preferably 100 nm or less. If the barrier layer is too thin, it is difficult to obtain a uniform and continuous film. If the barrier layer is too thick, the adhesion to the substrate is reduced, the thin film layer is easily broken, or it is colored by light interference. It is not preferable.

The water vapor permeability of a transparent plastic substrate with a barrier layer of 100 nm is usually 1 × 10 ⁻⁵ g / m ² / day or more, while usually 1 g / m ² / day or less, preferably 1 × 10 ⁻¹ g. / M ² / day or less, more preferably 1 × 10 ⁻² g / m ² / day or less. It is preferable from the point of the manufacturing cost of a barrier film that the water-vapor-permeation rate of a barrier layer is 1 * 10 < ^-5 > g / m < ² > / day or more. Moreover, it is preferable from the point of durability of an organic photoelectric conversion element that the water vapor transmission rate of a barrier layer is 1 g / m < ² > / day or less. The water vapor transmission rate is measured in a 40 degree 90% RH environment by a measurement using an apparatus equipped with a humidity sensor, an infrared sensor, a gas chromatograph according to JIS K7129, or by a cup method (JIS Z0208).

The barrier layer may be formed by a conventionally known method such as a vacuum deposition method, an ion plating method, or a sputtering method.
Further, an anchor layer may be provided between the transparent plastic substrate and the barrier layer. Since stress can be relaxed and flexibility can be obtained, the surface shape can be flattened, and high gas barrier properties can be obtained. In addition, the adhesion between the barrier layer and the substrate can be improved.

  Examples of the material for the anchor layer include a polymer of a compound containing at least an acrylate group, but a polymer of a compound containing a urethane group, an isocyanate group, an epoxy group, a methacrylate group, an amide group, an imide group, or the like, an organic siloxane Any type can be used as long as flatness such as a polymer of a polymer is obtained. Among these polymers, those suitably used from the viewpoint of film forming workability, gas barrier properties, and adhesion to the substrate are urethane acrylate polymers and polymers comprising a polyol and a compound containing an isocyanate group. is there.

The thickness of the anchor layer is not particularly limited as long as the thickness is such that the transparency is not impaired and the gas barrier property is maintained and the adhesion between the transparent plastic substrate and the barrier layer is ensured. Usually, it is 10 nm or more, preferably 20 nm or more, and is usually 3 μm or less, preferably 1 μm or less. By setting the thickness of the anchor layer to 10 nm or more and 3 μm or less, it is preferable to prevent peeling due to internal stress while ensuring adhesion, gas barrier properties, and transparency.
The anchor layer may be formed by a conventionally known method such as microgravure coating.

<Transparent electrode>
In the transparent electrode of the present invention, a transparent conductive thin film layer, a metal layer, and a transparent conductive thin film layer are laminated in that order. The material of the transparent conductive thin film layer that sandwiches the metal layer may be the same or different. As a material used for a transparent conductive thin film layer, it is preferable that it is as excellent in transparency and conductivity as possible. Here, excellent transparency means that when a thin film having a thickness of about 100 nm is formed, the visible light transmittance of the thin film is 60% or more, and excellent conductivity means that the thickness is about 100 nm. When the thin film is formed, the surface resistance value of the thin film is 1 × 10 ⁷ Ω / □ or less. These may be mixed with impurities depending on the application. Examples of materials that can be suitably used for the transparent conductive thin film layer include indium oxide doped with tin (ITO), indium oxide doped with zinc (IZO), indium oxide doped with tungsten (IWO), Cadmium and tin oxide (CTO), aluminum oxide (Al ₂ O ₃ ), zinc oxide (ZnO), zinc and aluminum oxide (AZO), magnesium oxide (MgO), thorium oxide (ThO ₂ ), Tin oxide (SnO ₂ ), lanthanum oxide (La ₂ O ₃ ), indium oxide (In ₂ O ₃ ), niobium oxide (Nb ₂ O ₃ ), antimony oxide (Sb ₂ O ₃ ), zirconium oxide (ZrO ₂ ), Cerium oxide (C
eO ₂ ), titanium oxide (TiO ₂ ), bismuth oxide (BiO ₂ ), and the like. A transparent high refractive index sulfide may be used. Specific examples include zinc sulfide (ZnS), cadmium sulfide (CdS), antimony sulfide (Sb ₂ S ₃ ), and the like. Etc. Among them, amorphous oxides such as zinc-doped indium oxide (IZO) and tungsten-doped indium oxide (IWO) are preferable, and do not crystallize even at a high temperature treatment of about 150 ° C. It is preferable because the possibility of unevenness on the surface is low.

  The crystal transition temperature (Tc) of the transparent conductive thin film layer is usually 150 ° C. or higher, preferably 180 ° C. or higher, more preferably 200 ° C. or higher, and usually 300 ° C. or lower, preferably 250 ° C. or lower. The crystal transition temperature (Tc) of the transparent conductive thin film layer is preferably 150 ° C. or more and 250 ° C. or less, which is preferable in that the surface unevenness of the transparent conductive thin film layer does not occur when an organic photoelectric conversion element is formed on a transparent plastic substrate. . The crystal transition temperature can be measured by a measuring method such as differential calorimetry.

The thickness of the transparent conductive thin film layer is determined in consideration of the transparency and electrical conductivity of the entire transparent electrode. Usually 10 nm or more, preferably 20 nm or more, on the other hand, usually 60 nm or less, preferably 50 nm or less. The transparent conductive thin film layer of the present invention has a specific resistance of usually 1 × 10 ⁻⁷ Ω / m or more, preferably 1 × 10 ⁻⁶ Ω / m or more, and usually 5 × 10 ⁻³ Ω / m.
Hereinafter, it is preferably 5 × 10 ⁻³ Ω / m or less, more preferably 1 × 10 ⁻⁴ Ω / m or less. In advance, a transparent conductive high-refractive-index thin film layer is formed on a glass substrate, and a film formation condition is determined by obtaining a specific resistance value from the film thickness and surface resistance. It is formed by stacking. The specific resistance of the transparent conductive thin film layer in the present invention can be easily estimated by examining the surface resistance of the transparent electrode. When the specific resistance value of the thin film layer is larger than 1 × 10 ² Ω · cm, the surface resistance of the transparent electrode is 1 × 10 ⁶ Ω · cm or more, and the surface is in an insulating state.

The surface resistance of the transparent electrode is usually 0.01Ω / □ or more, preferably 0.1Ω / □ or more, and usually 50Ω / □ or less, preferably 10Ω / □ or less. The surface resistance of the transparent electrode is 0.1Ω / □ or less. The value of □ or more and 10 Ω / □ or less is preferable in that the organic photoelectric conversion element is monolithically serialized and does not cause cost loss and cause no efficiency loss.
The specific resistance of the transparent conductive thin film layer can be measured by a measuring device such as Loresta (trademark) manufactured by Mitsubishi Chemical Analytics.

The roughness (Ra) of the transparent electrode can be measured using a Detek (trademark) 6M apparatus manufactured by Veeco.
The surface roughness of the transparent electrode is usually 0.01 nm or more, preferably 0.1 nm or more, on the other hand, usually 10 nm or less, preferably 5 nm or less, and the roughness (Ra) of the transparent electrode is 0.1 nm or more and 5 nm or less. By this, it is preferable at the point which prevents the short circuit of an organic photoelectric conversion element.

The material for the metal thin film layer used in the present invention is preferably a material having as good electrical conductivity as possible, and silver or a silver alloy is used. Silver has a specific resistance of 1.59 × 10 ⁻⁶ Ω · cm, and is most preferably used because it has the highest electrical conductivity among all materials and the visible light transmittance of the thin film. However, silver lacks stability when formed into a thin film and has a problem that it is susceptible to sulfidation and chlorination. Therefore, in order to increase the stability, instead of silver, an alloy of silver and gold, an alloy of silver and copper, an alloy of silver and palladium, an alloy of silver, copper and palladium, an alloy of silver and platinum, etc. are used. Also good. The thickness of the metal thin film layer is determined in consideration of the transparency and electrical conductivity of the entire transparent electrode. Usually 0.5 nm or more and 30 nm or less.

The total film thickness of the transparent conductive thin film layer, the metal thin film layer made of silver or silver alloy, and the transparent electrode formed by laminating the transparent conductive thin film layer is determined in consideration of optical characteristics and electrical characteristics, and the film thickness of each layer is determined.
It is obtained as the sum. The film thickness of the transparent electrode of the present invention is usually 60 nm or more and 100 nm or less. By setting the film thickness of the transparent electrode to 60 nm or more and 100 nm or less, the unevenness of the surface is not increased, and the contact resistance value between the transparent electrode outermost surface and the transparent electrode contact surface is relatively small, which is preferable.

  By providing a barrier layer between the transparent plastic substrate and the transparent electrode in which at least the transparent conductive thin film layer, the metal thin film layer, and the transparent conductive thin film layer are laminated in that order, the gap between the transparent conductive thin film layer and the transparent plastic substrate is provided. It is preferable at the point which improves the adhesiveness and durability of an organic photoelectric conversion element.

<Counter electrode>
The counter electrode can be formed of any material having conductivity. Examples of electrode materials include metals such as platinum, gold, silver, aluminum, chromium, nickel, copper, titanium, magnesium, calcium, barium, sodium, and alloys thereof; metal oxides such as indium oxide and tin oxide. Or alloys thereof (ITO, etc.); conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene, etc .; acids such as hydrochloric acid, sulfuric acid, sulfonic acid, Lewis acids such as FeCl ₃ , iodine, etc. Containing dopants such as halogen atoms, metal atoms such as sodium and potassium; conductive composite materials in which conductive particles such as metal particles, carbon black, fullerene and carbon nanotubes are dispersed in a matrix such as a polymer binder Can be mentioned. Especially, the material which has a deep work function, such as Au and ITO, is preferable for the electrode which collects holes. On the other hand, a material having a shallow work function such as Al or Ag is preferable for the electrode for collecting electrons. By optimizing the work function, there is an advantage of favorably collecting holes and electrons generated by light absorption.

In addition, there is no restriction | limiting in the formation method of a transparent conductive thin film layer, a metal thin film layer, and a counter electrode. For example, it can be formed by a dry process such as vacuum deposition or sputtering. Further, for example, it can be formed by a wet process using a conductive ink or the like. At this time, any conductive ink can be used. For example, a conductive polymer, a metal particle dispersion, or the like can be used.
Furthermore, two or more electrodes may be laminated, and characteristics such as electrical characteristics and wetting characteristics may be improved by surface treatment.

<Organic semiconductor layer>
The organic semiconductor layer according to the present invention may include other layers in addition to the active layer described later. In addition, the position which forms other layers is arbitrary unless the electric power generation of a solar cell element is inhibited. As the other layers, buffer layers are exemplified.

<Active layer>
It can be formed of any organic semiconductor. Organic semiconductors are classified into p-type and n-type depending on semiconductor characteristics. The p-type and n-type indicate whether it is a hole or an electron that contributes to electrical conduction, and depends on the electronic state, doping state, and trap state of the material. Accordingly, examples of organic semiconductors will be given below. However, p-type and n-type may not always be clearly classified, and some of the same substances exhibit both p-type and n-type characteristics.

Examples of p-type semiconductors include porphyrin compounds such as tetrabenzoporphyrin, tetrabenzocopper porphyrin, tetrabenzozinc porphyrin; phthalocyanine compounds such as phthalocyanine, copper phthalocyanine, zinc phthalocyanine; naphthalocyanine compounds; polyacenes of tetracene and pentacene; Examples thereof include oligothiophene and derivatives containing these compounds as a skeleton. Furthermore, polymers such as polythiophene, polyfluorene, polyphenylene vinylene, polytriallylamine, polyacetylene, polyaniline, polypyrrole and the like including poly (3-alkylthiophene) are exemplified.

Examples of n-type semiconductors include fullerene (C60, C70, C76); octaazaporphyrin; perfluoro compound of the above p-type semiconductor; naphthalenetetracarboxylic acid anhydride, naphthalenetetracarboxylic acid diimide, perylenetetracarboxylic acid anhydride, perylene. And aromatic carboxylic acid anhydrides such as tetracarboxylic acid diimides and imidized products thereof; and derivatives containing these compounds as a skeleton.

  The specific configuration of the organic semiconductor layer is arbitrary as long as at least a p-type semiconductor and an n-type semiconductor are contained. It may be constituted only by a single layer film or may be constituted by two or more laminated films. For example, an n-type semiconductor and a p-type semiconductor may be contained in separate films, or an n-type semiconductor and a p-type semiconductor may be contained in the same film. In addition, each of the n-type semiconductor and the p-type semiconductor may be used alone or in combination of two or more in any combination and ratio.

As a specific configuration example of the organic semiconductor layer, a bulk heterojunction type having a layer (i layer) in which a p-type semiconductor and an n-type semiconductor are phase-separated in the layer, a layer containing a p-type semiconductor (p layer), and n, respectively. Examples include a stacked type (hetero pn junction type) in which a layer containing a p-type semiconductor (p layer) has an interface, a Schottky type, and a combination thereof. Among these, a bulk heterojunction type and a combination of a bulk heterojunction type and a stacked type (p-i-n junction type) are preferable because they exhibit high performance.

Although there is no restriction | limiting in the thickness of each layer of the p layer of the organic-semiconductor layer, i layer, and n layer, Usually, it is preferable to set it as 3 nm or more, especially 10 nm or more, and usually 200 nm or less, especially 100 nm or less. Increasing the layer thickness tends to increase the uniformity of the film, and decreasing the thickness tends to improve the transmittance and decrease the series resistance.

<Buffer layer>
The buffer layer is a layer provided, for example, at the electrode interface facing the organic semiconductor layer in order to improve electrical characteristics. They can be classified into a hole extraction layer and an electron extraction layer, and can be provided between the active layer and an electrode for collecting holes or an electrode for collecting electrons, respectively.
Specific examples of the material for the buffer layer include poly (ethylenedioxythiophene): poly (styrenesulfonic acid) (PEDOT: PSS), lithium fluoride, 2,9 dimethyl-4,7-diphenyl-1,10- Examples include phenanthroline, phosphine oxide compounds, phosphine sulfide compounds, metal oxides, and the like. Preferred are poly (ethylenedioxythiophene): poly (styrene sulfonic acid) (PEDOT: PSS), phosphine oxide compound, phosphine sulfide compound, and metal oxide.

  As the phosphine oxide compound and phosphine sulfide compound, a phosphine oxide compound substituted with an aryl group and a phosphine sulfide compound substituted with an aryl group, more preferably a triarylphosphine oxide compound, a triarylphosphine sulfide compound, and a diarylphosphine Aromatic hydrocarbon compounds having two or more oxide units, aromatic hydrocarbon compounds having two or more diarylphosphine sulfide units, triarylphosphine oxide compounds composed of aryl substituted with fluorine atoms or perfluoroalkyl groups, diarylphosphine An aromatic hydrocarbon compound having two or more oxide units. In addition to the above materials, alkali metal or alkaline earth metal may be doped.

Examples of the metal oxide include titanium oxide (TiO ₂ ), zinc oxide (ZnO), zinc oxide doped with aluminum (AZO), indium oxide (In ₂ O ₃ ), nickel oxide (N
iO), molybdenum oxide (MoO ₃ ), indium oxide doped with gallium and zinc (IGZO), and the like. Among these, as the electron extraction layer, titanium oxide (TiO ₂ ), zinc oxide (ZnO) and zinc oxide doped with aluminum (AZO) and indium oxide are preferable, and as the hole extraction layer, nickel oxide (NiO), Molybdenum oxide (MoO ₃ ), indium oxide doped with gallium and zinc (IGZO) are preferable.

  PEDOT: PSS is usually used by applying a strongly acidic aqueous dispersion, which dissolves the transparent conductive thin film layer such as indium oxide and does not operate as a solar cell, or the conversion efficiency decreases with time, Although there is a possibility of accelerating the deterioration of a weak organic semiconductor, a metal oxide is preferable because the above problem does not occur.

<Layer structure of organic photoelectric conversion element>
The layer structure of the organic photoelectric conversion element of the present invention is not particularly limited, but is transparent plastic substrate / barrier layer / transparent electrode / organic semiconductor layer / counter electrode, transparent plastic substrate / anchor layer / barrier layer / transparent electrode / organic. Semiconductor layer / counter electrode, barrier layer / transparent plastic substrate / barrier layer / transparent electrode / organic semiconductor layer / counter electrode, barrier layer / anchor layer / transparent plastic substrate / anchor layer / barrier layer / transparent electrode / organic semiconductor layer / opposite It may be an electrode. In the above structure, a buffer layer (a hole extraction layer or an electron extraction layer) may be appropriately inserted between the transparent electrode or the counter electrode and the organic semiconductor layer.

<Solar cell module>
The organic photoelectric conversion device of the present invention is preferably used as a thin film solar cell as a solar cell device.
FIG. 2 is a cross-sectional view schematically showing the configuration of a thin film solar cell as one embodiment of the present invention.
As shown in FIG. 2, the thin film solar cell 14 of this embodiment includes a weather-resistant protective film 1, an ultraviolet cut film 2, a gas barrier film 3, a getter material film 4, a sealing material 5, and a solar cell element. 6, a sealing material 7, a getter material film 8, a gas barrier film 9, and a back sheet 10 in this order, and further a sealing material 11 that seals the edges of the weatherproof protective film 1 and the back sheet 10. I have. And light is irradiated from the side (downward in the figure) where the weather-resistant protective film 1 is formed, and the solar cell element 6 generates power. In addition, when using the sheet | seat with high waterproofness, such as a sheet | seat which adhere | attached the fluorine resin film on both surfaces of the aluminum foil as the back sheet | seat 10 mentioned later, it is not necessary to use the getter material film 8 and the gas barrier film 9 by use. Good.

[Weather-resistant protective film 1]
The weather-resistant protective film 1 is a film that protects the solar cell element 6 from weather changes. Some components of the solar cell element 6 are deteriorated by temperature change, humidity change, natural light, erosion caused by wind and rain, and the like. Therefore, by covering the solar cell element 6 with the weather-resistant protective film 1, the solar cell element 6 and the like are protected from weather changes and the power generation capacity is kept high.

Since the weather-resistant protective film 1 is located on the outermost layer of the thin-film solar cell 14, it is suitable as a surface covering material for the thin-film solar cell 14 such as weather resistance, heat resistance, transparency, water repellency, stain resistance and mechanical strength. It is preferable that it has a good performance and has the property of maintaining it for a long period of time in outdoor exposure.
Moreover, the weather-resistant protective film 1 is preferably one that transmits visible light from the viewpoint of not preventing the solar cell element 6 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is preferably 80% or more, more preferably 90% or more, and particularly preferably 95%.

  Furthermore, since the thin-film solar cell 14 is often heated by receiving light, it is preferable that the weather-resistant protective film 1 also has heat resistance. From this viewpoint, the melting point of the constituent material of the weather-resistant protective film 1 is usually preferably 100 ° C. or higher, more preferably 120 ° C. or higher, further preferably 130 ° C. or higher, usually 350 ° C. or lower, preferably 320 ° C. or lower. More preferred is 300 ° C. or lower. By increasing the melting point, it is possible to reduce the possibility that the weather resistant protective film 1 is melted and deteriorated when the thin film solar cell 14 is used.

  The material which comprises the weather-resistant protective film 1 is arbitrary as long as it can protect the solar cell element 6 from a weather change. Examples of the material include polyethylene resin, polypropylene resin, cyclic polyolefin resin, AS (acrylonitrile-styrene) resin, ABS (acrylonitrile-butadiene-styrene) resin, polyvinyl chloride resin, fluorine resin, polyethylene terephthalate, polyethylene naphthalate. Examples thereof include polyester resins such as phthalate, phenol resins, polyacrylic resins, polyamide resins such as various nylons, polyimide resins, polyamide-imide resins, polyurethane resins, cellulose resins, silicon resins, and polycarbonate resins.

  Of these, fluorine resins are preferred, and specific examples thereof include polytetrafluoroethylene (PTFE), 4-fluorinated ethylene-perchloroalkoxy copolymer (PFA), 4-fluorinated ethylene-6-fluoropropylene copolymer. Examples thereof include coalescence (FEP), 2-ethylene-4-fluorinated ethylene copolymer (ETFE), poly-3-fluoroethylene chloride (PCTFE), polyvinylidene fluoride (PVDF), and polyvinyl fluoride (PVF).

In addition, the weather-resistant protective film 1 may be formed with 1 type of material, and may be formed with 2 or more types of materials. Moreover, although the weather-resistant protective film 1 may be formed with the single layer film, the laminated | multilayer film provided with the film of two or more layers may be sufficient as it.
Although the thickness of the weather-resistant protective film 1 is not particularly defined, it is usually preferably 10 μm or more, more preferably 15 μm or more, and further preferably 20 μm or more. Further, it is usually preferably 200 μm or less, more preferably 180 μm or less, and further preferably 150 μm or less. When the thickness is 10 μm or more, the mechanical strength tends to increase, and when the thickness is 200 μm or less, the flexibility tends to increase.

Moreover, you may perform surface treatments, such as a corona treatment and a plasma treatment, for the weather-resistant protective film 1 in order to improve adhesiveness with another film.
The weatherproof protective film 1 is preferably provided on the outer side as much as possible in the thin-film solar cell 14. This is because more of the constituent members of the thin-film solar cell 14 can be protected.

[UV cut film 2]
The ultraviolet cut film 2 is a film that prevents the transmission of ultraviolet rays.
Some components of the thin film solar cell 14 are deteriorated by ultraviolet rays. Some of the gas barrier films 3 and 9 are deteriorated by ultraviolet rays depending on the type. Therefore, the ultraviolet cut film 2 is provided in the light receiving portion of the thin-film solar cell 14, and the ultraviolet cut film 2 covers the light receiving surface 6a of the solar cell element 6, so that the solar cell element 6 and, if necessary, the gas barrier films 3, 9 etc. Can be protected from ultraviolet rays and the power generation capacity can be kept high.

The degree of the ability to suppress the transmission of ultraviolet rays required for the ultraviolet cut film 2 is such that the transmittance of ultraviolet rays (for example, wavelength 300 nm) is preferably 50% or less, more preferably 30% or less, and more preferably 10% or less. Is particularly preferred.
Further, the ultraviolet cut film 2 is preferably one that transmits visible light from the viewpoint of not preventing the solar cell element 6 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more.

  Furthermore, since the thin film solar cell 14 is often heated by receiving light, the ultraviolet cut film 2 preferably has heat resistance. From this viewpoint, the melting point of the constituent material of the ultraviolet cut film 2 is usually preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and further preferably 130 ° C. or higher. Moreover, 350 degrees C or less is preferable normally, 320 degrees C or less is more preferable, and 300 degrees C or less is especially preferable. By setting the melting point to 100 ° C. or higher, the ultraviolet cut film 2 can be prevented from melting when the thin film solar cell 14 is used.

Moreover, the ultraviolet cut film 2 has a high softness | flexibility, its adhesiveness with an adjacent film is favorable, and what can cut water vapor | steam and oxygen is preferable.
The material which comprises the ultraviolet cut film 2 is arbitrary if the intensity | strength of an ultraviolet-ray can be weakened. Examples of the material include a film formed by blending an ultraviolet absorber with an epoxy, acrylic, urethane, or ester resin. Alternatively, a film in which a layer of an ultraviolet absorbent dispersed or dissolved in a resin (hereinafter referred to as “ultraviolet absorbing layer” as appropriate) is formed on a base film may be used.

As the ultraviolet absorber, for example, salicylic acid-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ones can be used. Of these, benzophenone and benzotriazole are preferred.
Examples of this include various aromatic organic compounds such as benzophenone and benzotriazole. In addition, a ultraviolet absorber may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

As described above, a film in which an ultraviolet absorbing layer is formed on a base film can be used as the ultraviolet absorbing film. Such a film can be produced, for example, by applying a coating solution containing an ultraviolet absorber on a substrate film and drying it.
Although the material of a base film is not specifically limited, For example, polyester is mentioned at the point from which the balance of heat resistance and a softness | flexibility is obtained.

  Application | coating can be performed by arbitrary methods. Examples include reverse roll coating, gravure coating, kiss coating, roll brushing, spray coating, air knife coating, wire barber coating, pipe doctor method, impregnation / coating method, and curtain coating method. In addition, these methods may be performed alone or in any combination of two or more.

The solvent used in the coating solution is not particularly limited as long as it can uniformly dissolve or disperse the UV absorber. For example, a liquid resin can be used as a solvent, and examples thereof include various synthetic resins such as polyester-based, acrylic-based, polyamide-based, polyurethane-based, polyolefin-based, polycarbonate-based, and polystyrene-based resins.
Further, for example, natural polymers such as gelatin and cellulose derivatives, water, and alcohol mixed solutions such as water and ethanol can also be used as the solvent. Further, an organic solvent may be used as the solvent. If an organic solvent is used, it becomes possible to dissolve or disperse the pigment and the resin, and to improve the coatability. In addition, 1 type may be used for a solvent and it may use 2 or more types together by arbitrary combinations and a ratio.

The coating solution may further contain a surfactant. Use of the surfactant improves the dispersibility of the ultraviolet absorbing dye in the resin. Thereby, in an ultraviolet absorption layer, generation | occurrence | production of the dent by adhesion of foreign matters etc. by a fine bubble, the repelling in a drying process, etc. are suppressed.
As the surfactant, known surfactants (cationic surfactants, anionic surfactants, and nonionic surfactants) can be used. Of these, silicon surfactants and fluorine surfactants are preferable. In addition, 1 type may be used for surfactant and it may use 2 or more types together by arbitrary combinations and a ratio.

In addition, the drying after apply | coating a coating liquid to a base film can employ | adopt well-known drying methods, such as hot air drying and drying by an infrared heater, for example. Among these, hot air drying with a high drying speed is preferable.
Examples of specific products of the ultraviolet cut film 2 include Cut Ace (MKV Plastic Co., Ltd.).

The ultraviolet cut film 2 may be formed of one kind of material or may be formed of two or more kinds of materials. Further, the ultraviolet cut film 2 may be formed of a single layer film, but may be a laminated film including two or more layers.
The thickness of the ultraviolet cut film 2 is not particularly limited, but is usually preferably 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more. Further, it is usually preferably 200 μm or less, more preferably 180 μm or less, and further preferably 150 μm or less. When the thickness is 5 μm or more, the absorption of ultraviolet rays tends to be increased, and when the thickness is 200 μm or less, the visible light transmittance tends to be increased.

Although the ultraviolet cut film 2 should just be provided in the position which covers at least one part of the light-receiving surface 6a of the solar cell element 6, Preferably it is provided in the position which covers all the light-receiving surfaces 6a of the solar cell element 6. FIG.
However, the ultraviolet cut film 2 may be provided at a position other than the position covering the light receiving surface 6 a of the solar cell element 6.

[Gas barrier film 3]
The gas barrier film 3 is a film that prevents permeation of water and oxygen.
The solar cell element 6 tends to be vulnerable to moisture and oxygen. In particular, transparent electrodes such as ZnO: Al, compound semiconductor solar cell elements, and organic solar cell elements may be deteriorated by moisture and oxygen. Therefore, by covering the solar cell element 6 with the gas barrier film 3, the solar cell element 6 can be protected from water and oxygen, and the power generation capacity can be kept high.
The degree of moisture resistance required for the gas barrier film 3 varies depending on the type of the solar cell element 6 and the like. For example, when the solar cell element 6 is a compound semiconductor solar cell element, the water vapor permeability per unit area (1 m ² ) per day is 1 × 10 ⁻¹ g / m ² / day or less. Is preferably 1 × 10 ⁻² g / m ² / day or less, more preferably 1 × 10 ⁻³ g / m ² / day or less, and further preferably 1 × 10 ⁻⁴ g / m ^2. / Day or less is particularly preferable, 1 × 10 ⁻⁵ g / m ² / day or less is particularly preferable, and 1 × 10 ⁻⁶ g / m ² / day or less is particularly preferable.

Moreover, when the solar cell element 6 is an organic solar cell element, it is preferable that the water vapor permeability per unit area (1 m ² ) per day is 1 × 10 ⁻¹ g / m ² / day or less. It is more preferably 1 × 10 ⁻² g / m ² / day or less, further preferably 1 × 10 ⁻³ g / m ² / day or less, and further preferably 1 × 10 ⁻⁴ g / m ² / day. Among them, the following is particularly preferable, and it is particularly preferably 1 × 10 ⁻⁵ g / m ² / day or less, and particularly preferably 1 × 10 ⁻⁶ g / m ² / day or less. The more water vapor has to pass through, the lower the degradation caused by the reaction of the solar cell element 6 and the transparent electrode such as ZnO: Al of the element 6 with moisture, thus increasing the power generation efficiency and extending the life.

The degree of oxygen permeability required for the gas barrier film 3 varies depending on the type of the solar cell element 6 and the like. For example, when the solar cell element 6 is a compound semiconductor solar cell element, the oxygen permeability per unit area (1 m ² ) per day is 1 × 10 ⁻¹ cc / m ² / day / atm or less. Preferably, it is 1 × 10 ⁻² cc / m ² / day / atm or less, more preferably 1 × 10 ⁻³ cc / m ² / day / atm or less, and further preferably 1 × 10 2. ⁻⁴ cc / m ² / day / atm or less is particularly preferable, and 1 × 10 ⁻⁵ cc / m ² / day / atm or less is particularly preferable, and 1 × 10 ⁻⁶ cc / m ² / day. / Atm or less is particularly preferable.

For example, when the solar cell element 6 is an organic solar cell element, the oxygen permeability per unit area (1 m ² ) per day is 1 × 10 ⁻¹ cc / m ² / day / atm or less. Preferably, it is 1 × 10 ⁻² cc / m ² / day / atm or less, more preferably 1 × 10 ⁻³ cc / m ² / day / atm or less, and further preferably 1 × 10 2. ⁻⁴ cc / m ² / day / atm or less is particularly preferable, and 1 × 10 ⁻⁵ cc / m ² / day / atm or less is particularly preferable, and 1 × 10 ⁻⁶ cc / m ² / day. / Atm or less is particularly preferable. The deterioration due to oxidation of the solar cell element 6 and the transparent electrode such as ZnO: Al of the element 6 is suppressed as the oxygen does not permeate.

  Conventionally, it has been difficult to mount the gas barrier film 3 having such a high moisture-proof and oxygen-blocking capability, so that a solar cell including an excellent solar cell element such as a compound semiconductor solar cell element and an organic solar cell element is realized. Although it was difficult to carry out, implementation of the thin film solar cell 14 which utilized the outstanding properties, such as a compound semiconductor type solar cell element and an organic solar cell element, becomes easy by applying such a gas barrier film 3.

  Further, the gas barrier film 3 is preferably one that transmits visible light from the viewpoint of not preventing the light absorption of the solar cell element 6. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually preferably 60% or more, preferably 70% or more, more preferably 75% or more, particularly preferably 80% or more, and 85% or more. Is particularly preferable, particularly preferably 90% or more, particularly preferably 95% or more, and most preferably 97% or more. This is to convert more sunlight into electrical energy.

  Furthermore, since the thin film solar cell 14 is often heated by receiving light, it is preferable that the gas barrier film 3 also has heat resistance. From this viewpoint, the melting point of the constituent material of the gas barrier film 3 is usually preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and further preferably 130 ° C. or higher. Moreover, 350 degrees C or less is preferable normally, 320 degrees C or less is more preferable, and 300 degrees C or less is further more preferable. By setting the melting point to 100 ° C. or higher, the possibility that the gas barrier film 3 is melted and deteriorated when the thin film solar cell 14 is used can be reduced.

The specific configuration of the gas barrier film 3 is arbitrary as long as the solar cell element 6 can be protected from water. However, since the manufacturing cost increases as the amount of water vapor or oxygen that can permeate the gas barrier film 3 increases, it is preferable to use an appropriate film considering these points comprehensively.
Hereinafter, the configuration of the gas barrier film 3 will be described with examples.
Two examples of the configuration of the gas barrier film 3 are preferable.

The first example is a film in which an inorganic barrier layer is disposed on a plastic film substrate.
In this case, the inorganic barrier layer may be formed only on one side of the plastic film substrate, or may be formed on both sides of the plastic film substrate. When forming on both surfaces, the number of inorganic barrier layers formed on both surfaces may be the same or different.

The second example is a film in which a unit layer composed of two layers in which an inorganic barrier layer and a polymer layer are arranged adjacent to each other is formed on a plastic film substrate. At this time, a unit layer composed of two layers in which an inorganic barrier layer and a polymer layer are arranged adjacent to each other is regarded as one unit, and this unit layer is composed of one unit (one inorganic barrier layer and one polymer layer are combined into one unit). (Meaning of unit) may be formed, but two or more units may be formed. For example, 2 to 5 units may be laminated.

The unit layer may be formed only on one side of the plastic film substrate, or may be formed on both sides of the plastic film substrate. When forming on both surfaces, the numbers of inorganic barrier layers and polymer layers formed on both surfaces may be the same or different.
In addition, when forming a unit layer on a plastic film substrate, an inorganic barrier layer may be formed and then a polymer layer may be formed thereon, or after forming a polymer layer and forming an inorganic barrier layer. Also good.

(Plastic film substrate)
The plastic film substrate used for the gas barrier film 3 is not particularly limited as long as it is a film capable of holding the above-described inorganic barrier layer and polymer layer, and can be appropriately selected from the purpose of use of the gas barrier film 3 and the like.
Examples of the plastic film base material include polyester resin, polyarylate resin, polyethersulfone resin, fluorene ring-modified polycarbonate resin, alicyclic modified polycarbonate resin, and acryloyl compound.

It is also preferable to use a condensation polymer containing spirobiindane and spirobichroman. Among the polyester resins, biaxially stretched polyethylene terephthalate (PET) and biaxially stretched polyethylene naphthalate (PEN) are preferably used as a plastic film substrate because they are excellent in thermal dimensional stability.
In addition, 1 type may be used for the material of a plastic film base material, and 2 or more types may be used together by arbitrary combinations and a ratio.

  The thickness of the plastic film substrate is not particularly defined, but is usually preferably 10 μm or more, more preferably 15 μm or more, and further preferably 20 μm or more. Further, it is usually preferably 200 μm or less, more preferably 180 μm or less, and further preferably 150 μm or less. Increasing the thickness tends to increase mechanical strength, and decreasing the thickness tends to increase flexibility.

  The plastic film substrate is preferably one that transmits visible light from the viewpoint of not preventing the solar cell element 6 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually preferably 60% or more, more preferably 70% or more, further preferably 75% or more, particularly preferably 80% or more, and particularly preferably 85% or more. Preferably, 90% or more is particularly preferable, 95% or more is particularly preferable, and 97% or more is most preferable. This is to convert more sunlight into electrical energy.

An anchor coat agent layer (anchor coat layer) may be formed on the plastic film substrate in order to improve adhesion to the inorganic barrier layer. Usually, the anchor coat layer is formed by applying an anchor coat agent.
Examples of the anchor coating agent include polyester resins, urethane resins, acrylic resins, oxazoline group-containing resins, carbodiimide group-containing resins, epoxy group-containing resins and isocyanate-containing resins, and copolymers thereof.

Among them, a combination of at least one of a polyester resin, a urethane resin, and an acrylic resin and at least one of an oxazoline group-containing resin, a carbodiimide group-containing resin, an epoxy group-containing resin, and an isocyanate group-containing resin is preferable. In addition, an anchor coat agent may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.
The thickness of the anchor coat layer is usually preferably 0.005 μm or more, more preferably 0.01 μm or more, usually 5 μm or less, and more preferably 1 μm or less. If the thickness is less than or equal to the upper limit of this range, the slipperiness is good, and there is almost no peeling from the plastic film substrate due to the internal stress of the anchor coat layer itself. Moreover, if it is the thickness more than the lower limit of this range, a uniform thickness can be maintained and it is preferable.

  In addition, in order to improve the applicability and adhesion of the anchor coating agent to the plastic film substrate, the plastic film substrate may be subjected to a surface treatment such as normal chemical treatment or electric discharge treatment before application of the anchor coating agent. Good.

(Inorganic barrier layer)
The inorganic barrier layer is usually a layer formed of a metal oxide, nitride or oxynitride. In addition, the metal oxide, nitride, and oxynitride which form an inorganic barrier layer may be 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  Examples of the metal oxide include oxides such as Si, Al, Mg, In, Ni, Sn, Zn, Ti, Cu, Ce, and Ta, nitrides, and oxynitrides. Among these, in order to achieve both high barrier properties and high transparency, it is preferable to include aluminum oxide or silicon oxide, and it is particularly preferable to include silicon oxide from the viewpoint of moisture permeability and light transmittance.

The ratio of each metal atom to oxygen atom is also arbitrary, but in order to improve the transparency of the inorganic barrier layer and prevent coloring, the oxygen atom ratio should be extremely small from the stoichiometric ratio of the oxide. Is preferred. On the other hand, in order to improve the denseness of the inorganic barrier layer and increase the barrier property, it is preferable to reduce oxygen atoms.
From this viewpoint, for example, when SiO _x is used as the metal oxide, the value of x is particularly preferably 1.5 to 1.8. For example, when AlO _x is used as the metal oxide, the value of x is particularly preferably 1.0 to 1.4.

Moreover, when an inorganic barrier layer is comprised from 2 or more types of metal oxides, it is preferable that an aluminum oxide and a silicon oxide are included as a metal oxide. Among them, when the inorganic barrier layer is made of aluminum oxide and silicon oxide, the ratio of aluminum and silicon in the inorganic barrier layer can be arbitrarily set, but the ratio of Si / Al is usually preferably 1/9 or more, 2/8 or more is more preferable. Moreover, 9/1 or less is preferable normally and 2/8 or less is more preferable.

  When the thickness of the inorganic barrier layer is increased, the barrier property tends to be increased. However, in order to prevent cracking and prevent cracking when bent, it is preferable to reduce the thickness. Therefore, the appropriate thickness of the inorganic barrier layer is usually preferably 5 nm or more, and more preferably 10 nm or more. Moreover, 1000 nm or less is preferable normally and 200 nm or less is more preferable.

  Although there is no restriction | limiting in the film-forming method of an inorganic barrier layer, Generally, it can carry out by sputtering method, a vacuum evaporation method, an ion plating method, plasma CVD method, etc. For example, the sputtering method can be formed by a reactive sputtering method using plasma using one or more metal targets and oxygen gas as raw materials.

(Polymer layer)
Any polymer can be used for the polymer layer, and for example, a film that can be formed in a vacuum chamber can be used. In addition, the polymer which comprises a polymer layer may use 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.
A wide variety of compounds can be used as the compound that gives the polymer, and examples include the following (i) to (vii). In addition, 1 type may be used for a monomer and it may use 2 or more types together by arbitrary combinations and a ratio.

  (I) Examples include siloxanes such as hexamethyldisiloxane. An example of a method for forming a polymer layer in the case of using hexamethyldisiloxane is to introduce hexamethyldisiloxane as a vapor into a parallel plate type plasma apparatus using an RF electrode, to cause a polymerization reaction in the plasma, The polymer layer can be formed as a polysiloxane thin film by being deposited on a plastic film substrate.

  (Ii) Examples include paraxylylene such as diparaxylylene. As an example of a method for forming a polymer layer in the case of using diparaxylylene, first, the vapor of diparaxylylene is heated at 650 ° C. to 700 ° C. in a high vacuum to generate thermal radicals. Then, the radical monomer vapor is introduced into the chamber and adsorbed to the plastic film substrate, and at the same time, the radical polymerization reaction proceeds to deposit polyparaxylylene to form a polymer layer.

  (Iii) For example, a monomer capable of alternately repeating addition polymerization of two kinds of monomers can be mentioned. The polymer thus obtained is a polyaddition polymer. Examples of the polyaddition polymer include polyurethane (diisocyanate / glycol), polyurea (diisocyanate / diamine), polythiourea (dithioisocyanate / diamine), polythioether urethane (bisethyleneurethane / dithiol), polyimine ( Bisepoxy / primary amine), polypeptide amide (bisazolactone / diamine) and polyamide (diolefin / diamide).

(Iv) Examples include acrylate monomers. The acrylate monomer includes monofunctional, bifunctional and polyfunctional acrylate monomers, and any of them may be used. However, in order to obtain an appropriate evaporation rate, degree of cure, cure rate, and the like, it is preferable to use a combination of two or more of the above acrylate monomers.
Examples of the monofunctional acrylate monomer include aliphatic acrylate monomers, alicyclic acrylate monomers, ether acrylate monomers, cyclic ether acrylate monomers, aromatic acrylate monomers, hydroxyl group-containing acrylate monomers, and carboxy group-containing acrylate monomers. Any of these can be used.

  (V) For example, a monomer capable of obtaining a photocationically cured polymer such as an epoxy-based resin and an oxetane-based polymer can be used. As an epoxy-type monomer, an alicyclic epoxy-type monomer, a bifunctional monomer, a polyfunctional oligomer, etc. are mentioned, for example. Examples of the oxetane monomer include monofunctional oxetane, bifunctional oxetane, and oxetane having a silsesquioxane structure.

(Vi) An example is vinyl acetate. When vinyl acetate is used as a monomer, polyvinyl alcohol is obtained by saponifying the polymer, and this polyvinyl alcohol can be used as a polymer.
(Vii) Examples thereof include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, monoethyl maleate, maleic anhydride and itaconic anhydride.

These constitute a copolymer with ethylene, and the copolymer can be used as a polymer. Furthermore, a mixture thereof, a mixture obtained by mixing a glycidyl ether compound, and a mixture with an epoxy compound can also be used as the polymer.
There is no restriction | limiting in the polymerization method of a monomer when superposing | polymerizing the said monomer and producing | generating a polymer. However, the polymerization is usually carried out after a composition containing a monomer is applied or deposited to form a film. As an example of the polymerization method, when a thermal polymerization initiator is used, the polymerization is started by contact heating with a heater or the like; radiation heating with infrared rays or microwaves; Moreover, when a photoinitiator is used, an active energy ray is irradiated and polymerization is started.

Various light sources can be used when irradiating active energy rays, such as mercury arc lamps, xenon arc lamps, fluorescent lamps, carbon arc lamps, tungsten-halogen radiation lamps, and sunlight irradiation light. Can do. Further, electron beam irradiation or atmospheric pressure plasma treatment can also be performed.
Examples of the method for forming the polymer layer include a coating method and a vacuum film forming method.

  When the polymer layer is formed by a coating method, for example, methods such as roll coating, gravure coating, knife coating, dip coating, curtain flow coating, spray coating, and bar coating can be used. Moreover, you may make it apply | coat the coating liquid for polymer layer formation in mist form. In this case, the average particle diameter of the droplets may be adjusted to an appropriate range. For example, in the case of forming a coating liquid containing a polymerizable monomer in the form of a mist on a plastic film substrate, the droplets The average particle size is preferably 5 μm or less, and more preferably 1 μm or less.

On the other hand, when forming a polymer layer by a vacuum film-forming method, film-forming methods, such as vapor deposition and plasma CVD, are mentioned, for example.
Although there is no limitation in particular about the thickness of a polymer layer, 10 nm or more is preferable normally. Moreover, 5000 nm or less is preferable normally, 2000 nm or less is more preferable, and 1000 nm or less is especially preferable.

By setting the thickness of the polymer layer to 10 nm or more, the uniformity of the thickness can be easily obtained, and structural defects of the inorganic barrier layer can be efficiently filled with the polymer layer, and the barrier property tends to be improved. Moreover, since the polymer layer itself becomes difficult to generate | occur | produce a crack by external force, such as a bending, by making the thickness of a polymer layer 5000 nm or less, barrier property can improve.
Particularly suitable gas barrier film 3 includes, for example, a film obtained by vacuum-depositing SiO _x on a base film such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN).

In addition, the gas barrier film 3 may be formed with 1 type of material, and may be formed with 2 or more types of materials. The gas barrier film 3 may be formed of a single layer film, but may be a laminated film including two or more layers.
The thickness of the gas barrier film 3 is not particularly defined, but is usually preferably 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more. Further, it is usually preferably 200 μm or less, more preferably 180 μm or less, and further preferably 150 μm or less. When the thickness is 5 μm or more, gas barrier properties tend to be increased, and when the thickness is 200 μm or less, flexibility is increased and visible light transmittance tends to be improved.

As long as the gas barrier film 3 covers the solar cell element 6 and can be protected from moisture and oxygen, the formation position is not limited. However, the front surface of the solar cell element 6 (surface on the light receiving surface side, lower surface in FIG. 2) and It is preferable to cover the back surface (the surface opposite to the light receiving surface; the upper surface in FIG. 2).
This is because the front and back surfaces of the thin film solar cell 14 are often formed in a larger area than the other surfaces. In this embodiment, the gas barrier film 3 covers the front surface of the solar cell element 6, and a gas barrier film 9 described later covers the back surface of the solar cell element 6.

  Then, the edges of the gas barrier films 3 and 9 are sealed with the sealing material 11, and the solar cell elements 6 are placed in the space surrounded by the gas barrier films 3 and 9 and the sealing material 11, so that the solar cell elements 6 It can be protected from oxygen. In addition, when using a highly waterproof sheet such as a sheet in which a fluororesin film is bonded to both surfaces of an aluminum foil as the back sheet 10 described later, it is not necessary to use at least one of the getter material film 8 and the gas barrier film 9 depending on the application. Good.

[Getter material film 4]
The getter material film 4 is a film that absorbs at least one of moisture and oxygen. Some components of the solar cell element 6 are deteriorated by moisture as described above, and some are deteriorated by oxygen. Therefore, by covering the solar cell element 6 with the getter material film 4, the solar cell element 6 and the like are protected from at least one of moisture and oxygen, and the power generation capacity is kept high.

  Here, unlike the gas barrier film 3 as described above, the getter material film 4 does not prevent moisture permeation but absorbs moisture. By using a film that absorbs moisture, when the solar cell element 6 is covered with the gas barrier film 3 or the like, the getter material film 4 absorbs moisture that slightly enters the space formed by the gas barrier films 3 and 9 and the sealing material 11. Can be captured and the influence of moisture on the solar cell element 6 can be eliminated.

The degree of water absorption capacity of the getter material film 4 is preferably usually 0.1 mg / cm ² or more, 0.5 mg / cm ² or more, more preferably, 1 mg / cm ² or more is more preferable. The higher this value, the higher the water absorption capacity, and the deterioration of the solar cell element 6 can be suppressed. Moreover, although there is no restriction | limiting in an upper limit, it is usually 10 mg / cm < ² > or less.
Further, when the getter material film 4 absorbs oxygen, when the solar cell element 6 is covered with the gas barrier films 3, 9, etc., it slightly enters the space formed by the gas barrier films 3, 9 and the seal material 11. Oxygen is captured by the getter material film 4 and the influence of the oxygen on the solar cell element 6 can be eliminated.

  Furthermore, the getter material film 4 is preferably one that transmits visible light from the viewpoint of not preventing the solar cell element 6 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually preferably 60% or more, more preferably 70% or more, further preferably 75% or more, particularly preferably 80% or more, and particularly preferably 85% or more. Preferably, 90% or more is particularly preferable, 95% or more is particularly preferable, and 97% or more is most preferable. This is to convert more sunlight into electrical energy.

  Furthermore, since the thin film solar cell 14 is often heated by receiving light, the getter material film 4 preferably has heat resistance. From this viewpoint, the melting point of the constituent material of the getter material film 4 is usually preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and further preferably 130 ° C. or higher. Moreover, 350 degrees C or less is preferable normally, 320 degrees C or less is more preferable, and 300 degrees C or less is further more preferable. By increasing the melting point, it is possible to reduce the possibility that the getter material film 4 melts and deteriorates when the thin-film solar cell 14 is used.

  The material constituting the getter material film 4 is arbitrary as long as it can absorb at least one of moisture and oxygen. As the material, for example, as a substance that absorbs moisture, alkali metal, alkaline earth metal, oxide of alkaline earth metal, hydroxide of alkali metal and alkaline earth metal, silica gel, zeolite compound, magnesium sulfate And sulfates such as sodium sulfate and nickel sulfate, and organometallic compounds such as aluminum metal complexes and aluminum oxide octylates.

Specifically, examples of the alkaline earth metal include Ca, Sr, and Ba. Examples of the alkaline earth metal oxide include CaO, SrO and BaO. Other examples include Zr—Al—BaO and aluminum metal complexes. Specific product names include, for example, OleDry (Futaba Electronics).
Examples of the substance that absorbs oxygen include activated carbon, silica gel, activated alumina, molecular sieve, magnesium oxide, and iron oxide. In addition, Fe, Mn and Zn and inorganic salts such as sulfate, chloride and nitrate of these metals are also included.

In addition, the getter material film 4 may be formed of one type of material or may be formed of two or more types of materials. The getter material film 4 may be formed of a single layer film, but may be a laminated film including two or more layers.
Although the thickness of the getter material film 4 is not particularly defined, it is usually preferably 5 μm or more, more preferably 10 μm or more, and further preferably 15 μm or more. Further, it is usually preferably 200 μm or less, more preferably 180 μm or less, and further preferably 150 μm or less. Increasing the thickness tends to increase mechanical strength, and decreasing the thickness tends to increase flexibility.

If the getter material film 4 is in the space formed by the gas barrier films 3, 9 and the sealing material 11, the formation position is not limited. However, the front surface of the solar cell element 6 (surface on the light receiving surface side; lower in FIG. 2). Side surface) and the back surface (surface opposite to the light receiving surface; upper surface in FIG. 2) are preferably covered.
This is because, in the thin film solar cell 14, the front and back surfaces are often formed in a larger area than the other surfaces, and therefore moisture and oxygen tend to enter through these surfaces. From this viewpoint, the getter material film 4 is preferably provided between the gas barrier film 3 and the solar cell element 6.

In this embodiment, the getter material film 4 covers the front surface of the solar cell element 6, a getter material film 8 described later covers the back surface of the solar cell element 6, and the getter material films 4 and 8 are respectively the solar cell element 6 and the gas barrier film 3. , 9 are located between them.
In addition, when using a highly waterproof sheet such as a sheet in which a fluororesin film is bonded to both surfaces of an aluminum foil as the back sheet 10 described later, it is not necessary to use at least one of the getter material film 8 and the gas barrier film 9 depending on the application. Good.

  The getter material film 4 can be formed by any method depending on the type of the water-absorbing agent or desiccant. For example, a method of attaching a film in which the water-absorbing agent or desiccant is dispersed with an adhesive, water-absorbing agent or desiccant A method of applying the solution by a spin coating method, an inkjet method, a dispenser method, or the like can be used. A film forming method such as a vacuum evaporation method or a sputtering method may be used.

As a film for a water absorbing agent or a desiccant, for example, polyethylene resin, polypropylene resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine resin, poly (meth) acrylic resin, polycarbonate resin, and the like can be used.
Among them, polyethylene resin, fluorine resin, cyclic polyolefin resin, and polycarbonate resin film are preferable. In addition, the said resin may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

[Sealing material 5]
The sealing material 5 is a film that reinforces the solar cell element 6. Since the solar cell element 6 is thin, the strength is usually weak, and thus the strength of the thin film solar cell tends to be weak. However, the strength can be maintained high by the sealing material 5.
Moreover, it is preferable that the sealing material 5 has high strength from the viewpoint of maintaining strength of the thin-film solar cell 14.
The specific strength is related to the strength of the weatherproof protective film 1 or the backsheet 10 other than the sealing material 5 and is difficult to define in general, but the entire thin-film solar cell 14 has good bending workability. In addition, it is preferable to have a strength that does not cause peeling of the bent portion.

  In addition, the sealing material 5 is preferably one that transmits visible light from the viewpoint of not preventing the solar cell element 6 from absorbing light. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually preferably 60% or more, more preferably 70% or more, further preferably 75% or more, particularly preferably 80% or more, and particularly preferably 85% or more. Preferably, 90% or more is particularly preferable, 95% or more is particularly preferable, and 97% or more is most preferable. This is to convert more sunlight into electrical energy.

  Furthermore, since the thin film solar cell 14 is often heated by receiving light, it is preferable that the sealing material 5 also has heat resistance. From this viewpoint, the melting point of the constituent material of the sealing material 5 is preferably preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and further preferably 130 ° C. or higher. Moreover, 350 degrees C or less is preferable normally, 320 degrees C or less is more preferable, and 300 degrees C or less is further more preferable. By increasing the melting point, it is possible to reduce the possibility that the sealing material 5 melts and deteriorates when the thin film solar cell 14 is used.

The thickness of the sealing material 5 is not particularly defined, but is usually preferably 100 μm or more, more preferably 150 μm or more, and further preferably 200 μm or more. Moreover, usually 700 micrometers or less are preferable, 600 micrometers or less are more preferable, and 500 micrometers or less are further more preferable. Increasing the thickness tends to increase the strength of the thin-film solar cell 14 as a whole, and decreasing the thickness tends to increase flexibility and improve visible light transmittance.
As a material which comprises the sealing material 5, what used the ethylene-vinyl acetate copolymer (EVA) resin composition for the film (EVA film) etc. can be used, for example. In order to improve weather resistance, the EVA film is usually blended with a crosslinking agent to form a crosslinked structure.

  As the crosslinking agent, an organic peroxide that generates radicals at 100 ° C. or higher is generally used. Examples of such an organic peroxide include 2,5-dimethylhexane; 2,5-dihydroperoxide; 2,5-dimethyl-2,5-di (t-butylperoxy) hexane; Di-t-butyl peroxide or the like can be used. The blending amount of these organic peroxides is usually preferably 5 parts by weight or less, more preferably 3 parts by weight or less, and usually 1 part by weight or more with respect to 100 parts by weight of the EVA resin. In addition, 1 type may be used for a crosslinking agent and it may use 2 or more types together by arbitrary combinations and a ratio.

  This EVA resin composition may contain a silane coupling agent for the purpose of improving the adhesive strength. Examples of silane coupling agents used for this purpose include γ-chloropropyltrimethoxysilane; vinyltrichlorosilane; vinyltriethoxysilane; vinyl-tris- (β-methoxyethoxy) silane; γ-methacryloxypropyltri Methoxysilane; β- (3,4-ethoxycyclohexyl) ethyltrimethoxysilane and the like can be mentioned. The blending amount of these silane coupling agents is usually preferably 5 parts by weight or less, more preferably 2 parts by weight or less, and usually 0.1 parts by weight or more with respect to 100 parts by weight of EVA resin.

In addition, 1 type may be used for a silane coupling agent and it may use 2 or more types together by arbitrary combinations and a ratio.
Furthermore, in order to improve the gel fraction of the EVA resin and improve the durability, a crosslinking aid may be included in the EVA resin composition. Examples of the crosslinking aid provided for this purpose include monofunctional crosslinking aids such as trifunctional crosslinking aids such as triallyl isocyanurate and triallyl isocyanate.

The amount of these crosslinking aids is usually preferably 10 parts by weight or less and more preferably 5 parts by weight or less with respect to 100 parts by weight of the EVA resin. Moreover, usually 1 weight part or more is preferable. In addition, 1 type may be used for a crosslinking adjuvant, and 2 or more types may be used together by arbitrary combinations and a ratio.
Furthermore, for the purpose of improving the stability of the EVA resin, the EVA resin composition may contain, for example, hydroquinone; hydroquinone monomethyl ether; p-benzoquinone; methyl hydroquinone. These compounding amounts are usually preferably 5 parts by weight or less with respect to 100 parts by weight of the EVA resin.

However, since the EVA resin cross-linking process requires a relatively long time of about 1 to 2 hours, it may cause a reduction in the production rate and production efficiency of the thin-film solar cell 14. Further, when used for a long period of time, the decomposition gas (acetic acid gas) of the EVA resin composition or the vinyl acetate group of the EVA resin itself may adversely affect the solar cell element 6 and reduce the power generation efficiency.
Therefore, as the sealing material 5, in addition to the EVA film, a copolymer film made of a propylene / ethylene / α-olefin copolymer can also be used. As this copolymer, the thermoplastic resin composition with which the following component 1 and the component 2 were mix | blended is mentioned, for example.

Component 1: The propylene polymer is usually preferably 0 part by weight or more, and more preferably 10 parts by weight or more. Moreover, 70 weight part or less is preferable normally, and 50 weight part or less is more preferable.
Component 2: The soft propylene-based copolymer is preferably 30 parts by weight or more, and more preferably 50 parts by weight or more. Moreover, 100 weight part or less is preferable normally, and 90 weight part or less is more preferable.

The total amount of component 1 and component 2 is 100 parts by weight. As described above, when component 1 and component 2 are in a preferred range, the moldability of the encapsulant 5 into a sheet is good, and the resulting encapsulant 5 has good heat resistance, transparency, and flexibility. Therefore, it is suitable for the thin film solar cell 14.
The thermoplastic resin composition in which the above component 1 and component 2 are blended preferably has a melt flow rate (ASTM D 1238, 230 degrees, load 2.16 g), usually 0.0001 g / 10 min or more. Moreover, 1000 g / 10min or less is preferable normally, 900 g / 10 min or less is more preferable, and 800 g / 10 min or less is further more preferable.

The melting point of the thermoplastic resin composition in which Component 1 and Component 2 are blended is usually preferably 100 ° C. or higher, and more preferably 110 ° C. or higher. Moreover, 140 degrees C or less is preferable normally, and 135 degrees C or less is more preferable.
Density of The thermoplastic resin composition Components 1 and 2 were compounded is preferably from 0.98 g / cm ³ or less, more preferably 0.95 g / cm ³ or less, more preferably 0.94 g / cm ³ or less .

In this sealing material 5, it is possible to mix | blend a coupling agent with the said component 1 and component 2 as an adhesion promoter with respect to a plastics. As the coupling agent, silane-based, titanate-based, and chromium-based coupling agents are preferably used, and in particular, a silane-based coupling agent (silane coupling agent) is preferably used.
Known silane coupling agents can be used and are not particularly limited. For example, vinyltriethoxysilane, vinyltrimethoxysilane, vinyltris (β-methoxy-ethoxysilane), γ-glycidoxypropyl-tri Examples include piltrimethoxysilane and γ-aminopropyltriethoxysilane. In addition, 1 type may be used for a coupling agent and it may use 2 or more types together by arbitrary combinations and a ratio.

In addition, the content of the silane coupling agent is preferably 0.1 parts by weight or more and usually 5 parts by weight or less with respect to 100 parts by weight of the thermoplastic resin composition (total amount of Component 1 and Component 2). Is preferable, and it is more preferable to contain 3 parts by weight or less.
The coupling agent may be grafted to the thermoplastic resin composition using an organic peroxide. In this case, it is preferable that 0.1-5 weight part of said coupling agents are included with respect to 100 weight part of thermoplastic resin compositions (total amount of component 1 and component 2). Even if a silane-grafted thermoplastic resin composition is used, the same or better adhesiveness as that of the silane coupling agent blend can be obtained for glass and plastic.

When the organic peroxide is used, the organic peroxide is usually preferably 0.001 part by weight or more with respect to 100 parts by weight of the thermoplastic resin composition (total amount of Component 1 and Component 2), and 0.01% by weight. Part or more is more preferable. Moreover, 5 weight part or less is preferable normally, and 3 weight part or less is more preferable.
Further, a copolymer made of an ethylene / α-olefin copolymer can be used as the sealing material 5. Examples of the copolymer include a laminate film having a hot tack property of 5 to 25 ° C., which is formed by laminating a resin composition for a sealing material comprising the following components A and B and a substrate.

Component A: ethylene resin.
Component B: a copolymer of ethylene and an α-olefin having the following properties (a) to (d).
(A) Density is 0.86-0.935 g / cm ³ .
(B) Melt flow rate (MFR) is 1 to 50 g / 10 min.
(C) There is one peak in the elution curve obtained by temperature rising elution fractionation (TREF); the peak temperature is 100 ° C. or lower.
(D) The integrated elution amount by temperature rising elution fractionation (TREF) is 90% or more at 90 ° C.

  The blending ratio of component A and component B (component A / component B) is generally preferably 50/50 or more, more preferably 55/45 or more, and still more preferably 60/40 or more in terms of weight ratio. Moreover, 99/1 or less is preferable normally, 90/10 or less is more preferable, and 85/15 or less is further more preferable. Increasing the amount of component B tends to increase transparency and heat sealability, and decreasing the amount of component B tends to increase the workability of the film.

  The melt flow rate (MFR) of the resin composition for a sealing material produced by blending component A and component B is usually preferably 2 g / 10 min or more, more preferably 3 g / 10 min or more, and usually 50 g / 10. Minutes or less is preferable, and 40 g / 10 minutes or less is more preferable. In addition, the measurement and evaluation of MFR can be implemented by the method based on JISK7210 (190 degreeC, 2.16kg load).

The melting point of the encapsulant resin composition is preferably 50 ° C. or higher, more preferably 55 ° C. or higher, usually 300 ° C. or lower, more preferably 250 ° C. or lower, and further preferably 200 ° C. or lower. By increasing the melting point, the possibility of melting and deterioration during use of the thin-film solar cell 14 can be reduced.
The density of the resin composition for a sealing material is preferably 0.80 g / cm ³ or more, and 0.85 g / cm.
³ or more is more preferable, 0.98 g / cm ³ or less is preferable, 0.95 g / cm ³ or less is more preferable, and 0.94 g / cm ³ or less is more preferable. The measurement and evaluation of density can be performed by a method based on JIS K7112.

Further, in the encapsulant 5 using the ethylene / α-olefin copolymer, a coupling agent can be used as in the case of using the propylene / ethylene / α-olefin copolymer.
Since the sealing material 5 described above does not generate a decomposition gas derived from the material, the solar cell element 6 is not adversely affected, and has good heat resistance, mechanical strength, flexibility (solar cell sealing property), and transparency. Have sex. Further, since no material cross-linking step is required, the manufacturing time of the thin film solar cell 100 during sheet molding can be greatly reduced, and the thin film solar cell 14 after use can be easily recycled.

In addition, the sealing material 5 may be formed with 1 type of material, and may be formed with 2 or more types of materials. Moreover, although the sealing material 5 may be formed with the single layer film, the laminated | multilayer film provided with the film of 2 or more layers may be sufficient as it.
The thickness of the sealing material 5 is usually preferably 2 μm or more, more preferably 5 μm or more, and further preferably 10 μm or more. Moreover, 500 micrometers or less are preferable normally, 300 micrometers or less are more preferable, and 100 micrometers or less are further more preferable. . Increasing the thickness tends to increase mechanical strength, and decreasing the thickness tends to increase flexibility and light transmittance.
Although there is no restriction | limiting in the position which provides the sealing material 5, Usually, it provides so that the solar cell element 6 may be inserted | pinched. This is for reliably protecting the solar cell element 6. In this embodiment, the sealing material 5 and the sealing material 7 are provided on the front surface and the back surface of the solar cell element 6, respectively.

[Solar cell element 6]
The solar cell element 6 is the same as the organic photoelectric conversion element described above.
・ Connection between solar cell elements
Although only one solar cell element 6 may be provided for each thin film solar cell 14, usually two or more solar cell elements 6 are provided. The specific number of solar cell elements 6 may be set arbitrarily. When a plurality of solar cell elements 6 are provided, the solar cell elements 6 are often arranged in an array.

When a plurality of solar cell elements 6 are provided, the solar cell elements 6 are usually electrically connected to each other, and electricity generated from the connected group of solar cell elements 6 is taken out from a terminal (not shown). At this time, in order to increase the voltage, the solar cell elements are usually connected in series.
Thus, when connecting the solar cell elements 6, it is preferable that the distance between the solar cell elements 6 is small, and the clearance between the solar cell element 6 and the solar cell element 6 is preferably narrow. This is because the light receiving area of the solar cell element 6 is widened to increase the amount of received light, and the amount of power generated by the thin film solar cell 14 is increased.

[Encapsulant 7]
The sealing material 7 is a film similar to the sealing material 5 described above, and the same material as the sealing material 7 can be used in the same manner except that the arrangement position is different.
Moreover, since the constituent member on the back side of the solar cell element 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

[Getter material film 8]
The getter material film 8 is the same film as the getter material film 4 described above, and the same material as the getter material film 4 can be used as necessary, except for the arrangement position.
Moreover, since the constituent member on the back side of the solar cell element 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used. It is also possible to use a film containing more water or oxygen absorbent than the getter material film 4. Examples of such absorbents include CaO, BaO, Zr-Al-BaO as moisture absorbents, and activated carbon, molecular sieves, etc. as oxygen absorbents.

[Gas barrier film 9]
The gas barrier film 9 is the same film as the gas barrier film 3 described above, and the same material as the gas barrier film 9 can be used as necessary except that the arrangement position is different.
Moreover, since the constituent member on the back side of the solar cell element 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

[Backsheet 10]
The back sheet 10 is the same film as the weather-resistant protective film 1 described above, and the same material as the weather-resistant protective film 1 can be used in the same manner except that the arrangement position is different. In addition, if the back sheet 10 is difficult to permeate water and oxygen, the back sheet 10 can also function as a gas barrier layer.
Moreover, since the constituent member on the back side of the solar cell element 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used. For this reason, it is particularly preferable to use the following (i) to (iv) as the backsheet 10.

  (I) As the back sheet 10, various resin films or sheets excellent in strength and excellent in weather resistance, heat resistance, water resistance, and light resistance can be used. For example, polyethylene resin, polypropylene resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine Resins, poly (meth) acrylic resins, polycarbonate resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyamide resins such as various nylons, polyimide resins, polyamideimide resins, polyarylphthalate resins , Silicone resin, polysulfone resin, polyphenylene sulfide resin, polyethersulfone resin, polyurethane resin, acetal resin, cellulose resin, and other various resin sheets It can be used.

Among these resin sheets, it is preferable to use sheets of fluorine resin, cyclic polyolefin resin, polycarbonate resin, poly (meth) acrylic resin, polyamide resin, and polyester resin. In addition, these may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.
(Ii) As the back sheet 10, a metal thin film can also be used. For example, corrosion-resistant aluminum metal foil, stainless steel thin film, and the like can be mentioned. In addition, the said metal may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

(Iii) As the back sheet 10, for example, a highly waterproof sheet in which a fluorine resin film is bonded to both surfaces of an aluminum foil may be used. Examples of the fluorine resin include ethylene monofluoride (trade name: Tedlar, manufactured by DuPont), polytetrafluoroethylene (PTFE), a copolymer of tetrafluoroethylene and ethylene or propylene (ETFE), and vinylidene fluoride resin. (PVDF) and vinyl fluoride resin (PVF). In addition, 1 type may be used for fluororesin and it may use 2 or more types together by arbitrary combinations and a ratio.

  (Iv) As the back sheet 10, for example, an inorganic oxide vapor-deposited film is provided on one side or both sides of the base film, and further, on both sides of the base film provided with the inorganic oxide vapor-deposited film, You may use what laminated | stacked the heat resistant polypropylene resin film. Usually, when a polypropylene resin film is laminated on the base film, the lamination is performed by laminating with a laminating adhesive. By providing an inorganic oxide vapor-deposited film, it can be used as a back sheet 10 having excellent moisture resistance that prevents intrusion of moisture, oxygen and the like.

・ Base film
Basically, as the base film, various resin films that are excellent in tight adhesion with an inorganic oxide vapor deposition film, etc., excellent in strength, weather resistance, heat resistance, water resistance and light resistance are used. Can be used.
For example, polyethylene resin, polypropylene resin, cyclic polyolefin resin, polystyrene resin, acrylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyvinyl chloride resin, fluorine Resins, poly (meth) acrylic resins, polycarbonate resins, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyamide resins such as various nylons, polyimide resins, polyamideimide resins, polyarylphthalate resins , Silicone resin, polysulfone resin, polyphenylene sulfide resin, polyethersulfone resin, polyurethane resin, acetal resin, cellulose resin, and other various resin fills It can be used.

Among these, it is preferable to use a film of a fluorine resin, a cyclic polyolefin resin, a polycarbonate resin, a poly (meth) acrylic resin, a polyamide resin, or a polyester resin.
Among the various resin films as described above, for example, fluorine resin films such as polytetrafluoroethylene (PTFE), vinylidene fluoride resin (PVDF), and vinyl fluoride resin (PVF) are used. It is more preferable.

Further, among the fluororesin films, in particular, a fluororesin film (PVF); a fluororesin film made of a copolymer of tetrafluoroethylene and ethylene or propylene (ETFE) is particularly preferable from the viewpoint of strength and the like. preferable. In addition, the said resin may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.
Of the various resin films as described above, it is more preferable to use a film of a cyclic polyolefin resin such as cyclopentadiene and a derivative thereof, cyclohexadiene and a derivative thereof.
As a film thickness of a base film, 12 micrometers or more are preferable normally, 20 micrometers or more are more preferable, and 300 micrometers or less are preferable normally, and 200 micrometers or less are more preferable.

・ Deposited film of inorganic oxide
As the inorganic oxide vapor-deposited film, basically any thin film on which a metal oxide is vapor-deposited can be used. For example, a deposited film of an oxide of silicon (Si) or aluminum (Al) can be used. At this time, for example, SiO _x (x = 1.0 to 2.0) can be used as silicon oxide, and for example, AlO _x (x = 0.5 to 1.5) can be used as aluminum oxide. .

In addition, the kind of metal and inorganic oxide to be used may be 1 type, and may use 2 or more types together by arbitrary combinations and ratios.
The thickness of the deposited inorganic oxide film is usually preferably 50 mm or more, more preferably 100 mm or more. Also, it is usually preferably 4000 mm or less, more preferably 1000 mm or less.
As a method for forming the deposited film, a chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a plasma chemical vapor deposition method, a thermal chemical vapor deposition method, or a photochemical vapor deposition method can be used. Specifically, for example, on one surface of the base film, a monomer gas for vapor deposition such as an organosilicon compound is used as a raw material, and an inert gas such as argon gas and helium gas is used as a carrier gas. A vapor deposition film of an inorganic oxide such as silicon oxide can be formed using a low temperature plasma chemical vapor deposition method using oxygen gas or the like as a supply gas and using a low temperature plasma generator or the like.

-Polypropylene resin film As a polypropylene resin, the homopolymer of propylene; the copolymer of a propylene and another monomer (for example, alpha olefin etc.) can be used, for example. Moreover, an isotactic polymer can also be used as a polypropylene resin.
The melting point of the polypropylene-based resin is usually preferably 164 ° C to 170 ° C, the specific gravity is usually preferably 0.90 to 0.91, and the molecular weight is usually preferably 100,000 to 200,000.

Polypropylene resins are largely controlled by their crystallinity, but high isotactic polymers have excellent tensile strength and impact strength, good heat resistance and bending fatigue strength, and workability. Is very good.
·adhesive
When a polypropylene resin film is laminated on the base film, a laminating adhesive is usually used. Thereby, a base film and a polypropylene resin film are laminated | stacked via the adhesive bond layer for lamination.

  Examples of the adhesive constituting the adhesive layer for laminating include, for example, a polyvinyl acetate adhesive, a polyacrylate adhesive, a cyanoacrylate adhesive, an ethylene copolymer adhesive, a cellulose adhesive, and a polyester adhesive. Adhesives, polyamide adhesives, polyimide adhesives, amino resin adhesives, phenol resin adhesives, epoxy adhesives, polyurethane adhesives, reactive (meth) acrylic adhesives, silicon adhesives, etc. Is mentioned. In addition, 1 type may be used for an adhesive agent and it may use 2 or more types together by arbitrary combinations and a ratio.

The composition system of the adhesive may be any composition form such as an aqueous type, a solution type, an emulsion type, and a dispersion type. Further, the property may be any of film / sheet, powder, solid and the like. Furthermore, the bonding mechanism may be any form such as a chemical reaction type, a solvent volatilization type, a heat melting type, and a hot pressure type.
The adhesive can be applied by, for example, a roll coating method, a gravure roll coating method, a kiss coating method, and other coating methods, a printing method, and the like. As the amount of ^{coating, 0.1g / m 2 ~10g / m} 2 is preferable in the dry state.

[Sealant 11]
The sealing material 11 includes the weatherproof protective film 1, the ultraviolet cut film 2, the gas barrier film 3, the getter material film 4, the sealing material 5, the sealing material 7, the getter material film 8, the gas barrier film 9, and the back sheet 10. It is a member that seals the edge so that moisture and oxygen do not enter the space covered with these films.

The degree of moisture capacity required for the sealing member 11 is preferably water vapor transmission rate per day unit area (1 m ²⁾ is not more than ^{0.1g / m 2 / day, 0.05g} / m 2 / More preferably, it is not more than day.
Conventionally, since it has been difficult to mount the sealing material 11 having such a high moisture-proof capability, it is possible to realize a solar cell including an excellent solar cell element such as a compound semiconductor solar cell element and an organic solar cell element. Although it was difficult, the implementation of the thin-film solar cell 14 utilizing the excellent properties of the compound semiconductor solar cell element and the organic solar cell element is facilitated by applying such a sealing material 11.

  Furthermore, since the thin film solar cell 14 is often heated by receiving light, it is preferable that the sealing material 11 also has heat resistance. From this viewpoint, the melting point of the constituent material of the sealing material 11 is usually preferably 100 ° C. or higher, more preferably 120 ° C. or higher, and further preferably 130 ° C. or higher. Further, it is usually preferably 250 ° C. or lower, more preferably 200 ° C. or lower, and further preferably 180 ° C. or lower. By setting the melting point to 100 ° C. or higher, the sealing material 11 can be prevented from melting when the thin film solar cell 14 is used.

Examples of the material constituting the sealing material 11 include polymers such as fluorine resin, silicon resin, and acrylic resin.
In addition, the sealing material 11 may be formed with 1 type of material, and may be formed with 2 or more types of materials.
The sealing material 11 is provided at a position where at least the edges of the gas barrier films 3 and 9 can be sealed. Thereby, the space surrounded by at least the gas barrier films 3 and 9 and the sealing material 11 can be sealed, and moisture and oxygen can be prevented from entering the space.

Although there is no restriction | limiting in the method of forming this sealing material 11, For example, it can form by inject | pouring material between the weather-resistant protective film 1 and the back sheet | seat 10. FIG. Specific examples of the forming method include the following methods.
That is, for example, while the curing of the sealing material 5 proceeds, the semi-cured thin-film solar cell 14 is taken out from the laminating apparatus, and is the outer peripheral portion of the solar cell element 6, which is the weatherproof protective sheet 1 and the back sheet 10. A liquid polymer may be injected into a portion between the two and the polymer may be cured together with the sealing material 5.

  Further, after the sealing material 5 has been cured, it may be taken out from the laminating apparatus and cured alone. The temperature range for crosslinking and curing the polymer is usually preferably 130 ° C. or higher, and more preferably 140 ° C. or higher. Moreover, 180 degrees C or less is preferable normally, and 170 degrees C or less is more preferable.

[Dimensions]
The thin film solar cell 14 of the present embodiment is usually a thin film member. By forming the thin film solar cell 14 as a film-like member in this way, the thin film solar cell 14 can be easily installed in building materials, automobiles, interiors, and the like. The thin-film solar cell 14 is light and difficult to break, and thus a highly safe solar cell can be obtained and can be applied to a curved surface, so that it can be used for more applications. Since it is thin and light, it is preferable in terms of distribution such as transportation and storage. Furthermore, since it is in the form of a film, it can be manufactured in a roll-to-roll manner, and the cost can be greatly reduced.

Although there is no restriction | limiting in the specific dimension of the thin film solar cell 14, As for the thickness, 300 micrometers or more are preferable normally, 500 micrometers or more are more preferable, and 700 micrometers or more are further more preferable. Moreover, 3000 micrometers or less are preferable normally, 2000 micrometers or less are more preferable, and 1500 micrometers or less are further more preferable.
[Production method]
Although there is no restriction | limiting in the manufacturing method of the thin film solar cell 14 of this embodiment, For example, between the weather-resistant protective film 1 and the back sheet | seat 10, the 1 or 2 or more solar cell element 6 was connected in series or in parallel. The product can be manufactured by laminating with a general vacuum laminating apparatus together with the ultraviolet cut film 2, the gas barrier films 3, 9, the getter material films 4, 8 and the sealing materials 5, 7.

In this case, the heating temperature is usually preferably 130 ° C. or higher, and more preferably 140 ° C. or higher. Moreover, 180 degrees C or less is preferable normally, and 170 degrees C or less is more preferable.
The heating time is usually preferably 10 minutes or longer, more preferably 20 minutes or longer. Moreover, 100 minutes or less is preferable normally and 90 minutes or less are more preferable.
The pressure is usually preferably 0.001 MPa or more, and more preferably 0.01 MPa or more. Moreover, 0.2 MPa or less is preferable normally and 0.1 MPa or less is more preferable. By setting the pressure within this range, sealing can be performed reliably, and the sealing materials 5 and 7 from the end can be prevented from protruding and film thickness reduction due to overpressure can be suppressed, and dimensional stability can be ensured.

[Usage]
There is no restriction | limiting in the use of the thin film solar cell 14 mentioned above, It is arbitrary. For example, as schematically shown in FIG. 3, a solar cell module 13 in which a thin film solar cell 14 is provided on a certain base material 12 is prepared and used at a place of use. As a specific example, when a building material plate is used as the base material 12, a thin film solar cell 14 is provided on the surface of the plate material to produce a solar cell panel as the solar cell module 13, and this solar cell panel is attached to the outer wall of the building. It can be installed and used.

  The substrate 12 is a support member that supports the solar cell element 6. Examples of the material for forming the substrate 12 include inorganic materials such as glass, sapphire, and titania; polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, fluorine. Resin films, vinyl chloride, polyethylene, cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, organic materials such as polyurethane, polycarbonate, polyarylate and polynorbornene; paper materials such as paper and synthetic paper; metals such as stainless steel, titanium and aluminum In addition, a composite material such as a material whose surface is coated or laminated in order to impart insulating properties.

In addition, 1 type may be used for the material of a base material, and 2 or more types may be used together by arbitrary combinations and a ratio. Moreover, carbon fiber may be included in these organic materials or paper materials to reinforce the mechanical strength.
Examples of fields to which the thin film solar cell of the present invention is applied include solar cells for building materials, solar cells for automobiles, solar cells for interiors, solar cells for railways, solar cells for ships, solar cells for airplanes, solar cells for spacecraft. It is suitable for use in batteries, solar cells for home appliances, solar cells for mobile phones, solar cells for toys, and the like. Specific examples include the following.

1. Architectural use
1.1 Solar cell as house roofing material
When a roof plate or the like is used as the base material, a thin film solar cell is provided on the surface of the plate material to produce a solar cell panel as a solar cell module, and this solar cell panel is installed on the roof of the house. That's fine. Moreover, a roof tile can also be used directly as a base material. The solar cell of the present invention is suitable because it can be brought into close contact with the roof tiles by taking advantage of its flexibility.

1.2 Rooftop
It can also be installed on the roof of a building. A solar cell module in which a thin film solar cell is provided on a substrate can be prepared and installed on the roof of a building. At this time, it is preferable to use a waterproof sheet together with the base material to have a waterproof action. Furthermore, taking advantage of the property that the thin film solar cell of the present invention has flexibility, it can be brought into close contact with a roof that is not flat, for example, a folded roof. Also in this case, it is preferable to use a waterproof sheet in combination.

1.3 Toplight The thin-film solar cell of the present invention can also be used as an exterior at the entrance or at the atrium. Curves are often used for entrances and the like that have undergone some design processing, and in such a case, the flexibility of the thin film solar cell of the present invention is utilized. In addition, there is a case of see-through in an entrance or the like. In such a case, the green color of the organic solar cell is suitable because a design aesthetic can be obtained in an era when environmental measures are regarded as important.

1.4 Wall
When a building material plate is used as a base material, a thin film solar cell is provided on the surface of the plate material to produce a solar cell panel as a solar cell module, and the solar cell panel may be installed on the outer wall of a building and used. . It can also be installed on curtain walls. In addition, it can be attached to a spandrel or a vertical.

In this case, although there is no restriction | limiting in the shape of a base material, Usually, a board | plate material is used. Moreover, what is necessary is just to set the material of a base material, a dimension, etc. arbitrarily according to the use environment. As an example of such a substrate, Alpolic (registered trademark; manufactured by Mitsubishi Plastics) and the like can be mentioned.
1.5 windows
It can also be used for see-through windows. The green color of the organic solar cell is preferable because a design aesthetic can be obtained in an era when environmental measures are important.

1.6 Other
It can also be used for eaves, louvers, handrails, etc. Even in such a case, the flexibility of the thin film solar cell of the present invention is suitable for these applications.
2. Interior
The thin film solar cell of the present invention can also be attached to a blind slat. Since the thin-film solar cell of the present invention is lightweight and rich in flexibility, such a use is possible. Further, the contents window can be used by utilizing the characteristic that the organic solar cell element is see-through.

3. Vegetable factory
The number of plant factories that use illumination light such as fluorescent lamps is increasing, but the current situation is that it is difficult to reduce cultivation costs due to the cost of lighting and replacement of light sources. Then, the thin film solar cell of this invention can be installed in a vegetable factory, and the illumination system combined with LED or the fluorescent lamp can be produced.

At this time, it is preferable to use an illumination system that combines an LED having a longer life than a fluorescent lamp and the solar cell of the present invention, because the cost required for illumination can be reduced by about 30% compared to the current situation. Moreover, the solar cell of this invention can also be used for the roof and side wall of the reefer container (reefer container) which conveys vegetables etc. at fixed temperature.
4). Road Material / Civil Engineering The thin film solar cell of the present invention can also be used for an outer wall of a parking lot, a sound insulation wall of an expressway, an outer wall of a water purification plant, and the like.

5. Car
The thin film solar cell of the present invention can be used on the surfaces of automobile bonnets, roofs, trunk lids, doors, front fenders, rear fenders, pillars, bumpers, rearview mirrors, and the like. The obtained electric power can be supplied to any of a traveling motor, a motor driving battery, an electrical component, and an electrical component battery. By providing the power generation status in the solar cell panel and the control means for selecting according to the power usage status in the motor for driving, the battery for driving the motor, the electrical equipment, and the battery for electrical equipment, the obtained power is Can be used properly and efficiently
In the above case, the shape of the substrate 12 is not limited, but a plate material is usually used. Moreover, what is necessary is just to set the material of the base material 12, a dimension, etc. arbitrarily according to the use environment.
Examples of such a substrate 12 include Alpolic (registered trademark; manufactured by Mitsubishi Plastics).

<Performance evaluation of solar cell module>
The solar cell module according to the present invention is characterized by having the following performance.
For example, in the case of an organic thin-film solar cell, performance can be evaluated by performing the acceleration test shown below and comparing changes in photoelectric conversion characteristics before and after the test.

Evaluation method: The acceleration test is performed in an environment tester (for example, SH-241 manufactured by Espec Corp.) in a high-temperature and high-humidity environment. The high temperature and high humidity environment is preferably 40 ° C. 90% RH or 85 ° C. 85% RH. The test period can be appropriately selected depending on the device constituent material, but it is preferable to carry out the test for 24 hours or more. As for the photoelectric conversion characteristics, the current and voltage characteristics are measured by irradiating an organic thin-film solar cell with AM1.5G light with an irradiation intensity of 100 mW / cm ² using a solar simulator. Energy conversion efficiency (PCE), short-circuit current, open-circuit voltage, FF (fill factor), series resistance, and shunt resistance can be obtained from a current / voltage curve obtained from such measurement.

As an expression for comparing the photoelectric conversion characteristics before and after the acceleration test, for example, PCE change rate = (PCE after the acceleration test) / (PCE before the acceleration test) can be given.
That is, the energy conversion efficiency (PCE) change rate of the organic electronic device according to the present invention is usually 0.86 or more after the acceleration test with respect to the initial performance, as defined by the above formula, 0.88 or more, more preferably 0.90 or more.

  The solar cell module according to the present invention has good weather resistance. Even if a weather resistance test is performed using an outdoor exposure test or a weather resistance tester, the performance is maintained and high durability performance is exhibited. It is thought that electrode deterioration is suppressed by the presence of the anticorrosion layer. Moreover, when a weather-resistant protective sheet is laminated | stacked, it has higher weather resistance.

Examples The present invention will be described more specifically with reference to examples. However, the present invention is not limited to the description of the following examples unless it exceeds the gist.
<PCE change rate measurement>
The PCE change rate of the organic photoelectric conversion element can be obtained by performing a durability test as follows.
Each of the produced organic photoelectric conversion elements was subjected to an acceleration test, and the change in photoelectric conversion characteristics before and after the test was compared. The acceleration test was carried out for 10 hours at 85 ° C. and 85% RH in a small environmental tester (Espec SH-241), and the photoelectric conversion characteristic value was measured with an organic thin film solar cell using a solar simulator (manufactured by Spectrometer Co., Ltd.). The light conversion efficiency (PCE) is obtained from the obtained current-voltage curve by irradiating light of 5 G condition with an irradiation intensity of 100 mW / cm ² .

Here, the PCE change rate is defined as follows.
PCE change rate = (PCE after acceleration test) / (PCE before acceleration test)
<Repeated bending resistance test>
The prepared organic photoelectric conversion element is repeatedly wound 100 times on a round bar having a diameter of 30 mm with the surface on which the organic photoelectric conversion element is located outside, and then the PCE change rate is obtained by the same method as the PCE change rate measurement.

<Process for producing organic photoelectric conversion element>
A silicon oxide thin film layer having a thickness of 100 nm is formed on one surface of a PEN resin film (Q65 manufactured by Teijin DuPont) by a high frequency plasma sputtering method. For the formation of the silicon oxide thin film layer, silicon oxide is used as a target, and when the degree of vacuum in the chamber reaches 1 × 10 ⁻⁴ Pa or less, 5% oxygen-containing argon gas is introduced to a gas pressure of 0.3 Pa. The sputtering film is formed without heating the substrate. An IZO thin film layer having a thickness of 45 nm is formed on the silicon oxide film by a direct current sputtering method. For forming the IZO thin film layer, a target obtained by mixing and baking zinc oxide and indium oxide at a weight ratio of 1: 9 is used as a target. When the degree of vacuum in the chamber reaches 1 × 10 ⁻⁴ Pa or less, argon gas with a purity of 99.9999 mass% is introduced into the chamber to a gas pressure of 0.6 Pa, and oxygen is contained in 1% film forming gas. Then, sputtering is performed without heating the substrate.

Next, a silver thin film layer having a thickness of 15 nm is formed on the IZO thin film layer by a direct current sputtering method. When the degree of vacuum in the chamber reaches 1 × 10 ⁻⁴ Pa or less, argon gas having a purity of 99.9999 mass% is introduced into the chamber to a gas pressure of 0.6 Pa, and sputtering is performed without heating the substrate. Film.
Next, an IZO thin film layer having a thickness of 45 nm is formed on the silver thin film layer in the same manner as described above.
Next, a 50 nm thick zinc oxide thin film layer is formed as a metal oxide layer on the IZO thin film by DC sputtering. The zinc oxide thin film layer is formed under the same conditions as the IZO thin film layer except that zinc oxide is used as a target.

A photoelectric conversion layer having a thickness of 100 nm is formed on the zinc oxide layer. Poly (3-hexylthiophene) and phenyl C61 butyric acid methyl ester are each dissolved in monochlorobenzene so as to be 1% by weight. The obtained solution is dropped on the zinc oxide buffer layer, and a mixed thin film of poly (3-hexylthiophene) and phenyl C61 butyric acid methyl ester is obtained by spin coating (rotation speed: 500 rpm, time: 60 seconds). Thereafter, heating is performed at 150 ° C. for 15 minutes using a hot plate in a nitrogen atmosphere.

A buffer layer having a thickness of 200 nm is formed on the photoelectric conversion layer. H. C. Clevios ^™ F CPP105D manufactured by Stark Co. is dropped onto the photoelectric conversion layer, and poly (3,4-ethylenedioxythiophene) and poly (styrenesulfonic acid) are mixed by spin coating (rotation speed: 1500 rpm, time: 30 seconds). A thin film consisting of the mixture is obtained. Thereafter, heating is performed at 120 ° C. for 10 minutes using a hot plate in a nitrogen atmosphere.

A silver electrode layer having a thickness of 100 nm is formed on the buffer layer at a deposition rate of 0.1 nm / second by vacuum deposition.
As described above, an organic thin-film solar cell element having a light-receiving area portion having a size of 2 mm × 2 mm is obtained.
[Comparative Example 1]
An organic thin-film solar cell element can be produced in the same manner as in Example 1 except that no silicon oxide film is produced.

  About the organic thin-film solar cell element obtained in Example 1, the PCE change rate measurement and the repeated bending resistance test are performed, respectively, so that the PCE change rate is smaller than that obtained in Comparative Example 1 and the repeated bending resistance is obtained. Things are expected to be obtained.

100 Substrate 200 Barrier layer 300 Transparent electrode 310 Transparent conductive thin film layer 320 Metal thin film layer 330 Transparent conductive thin film layer 400 Organic semiconductor layer 410 Buffer layer (electron extraction layer)
420 Active layer 430 Buffer layer (hole extraction layer)
500 Counter electrode 1 Weatherproof protective film
2 UV cut film
3,9 Gas barrier film
4,8 Getter material film
5,7 Sealing material
6 Solar cell element 10 Back sheet
11 Sealing material
12 Base material
13 Solar cell unit
14 Thin film solar cells

Claims (6)

  In an organic photoelectric conversion element in which at least a transparent plastic substrate, a transparent electrode, an organic semiconductor layer, and a counter electrode are stacked in that order, the transparent electrode is formed by stacking at least a transparent conductive thin film layer, a metal thin film layer, and a transparent conductive thin film layer in that order. An organic photoelectric conversion element, wherein a barrier layer is provided between the substrate and the transparent electrode.   The organic photoelectric conversion element according to claim 1, wherein a metal oxide layer is provided between the transparent electrode and the organic semiconductor layer. The organic photoelectric conversion element according to claim 1, wherein the transparent conductive thin film layer has a crystal transition temperature (Tc) of 150 ° C. or more and a specific resistance of 5 × 10 ⁻³ Ω / m or less.   The organic photoelectric conversion element according to claim 1, wherein the transparent electrode has a surface resistance of 10Ω / □ or less.   The organic photoelectric conversion element according to any one of claims 1 to 4, wherein the transparent conductive thin film layer is indium oxide doped with zinc or indium oxide doped with tungsten.   The solar cell module containing the organic photoelectric conversion element of Claims 1 thru | or 5.

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