JP2016225628A - Organic Thin Film Solar Cell Module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic thin film solar cell module which enhances workability and designability after construction.SOLUTION: In an organic thin film solar cell module where a first gas barrier layer 2, a first sealing layer 4, an organic thin film solar cell element 9, a second sealing layer 3, and a second gas barrier layer 1 are laminated sequentially, and a collection wire 11 connected electrically with the organic thin film solar cell element 9 is provided between the first sealing layer 4 and the organic thin film solar cell element 9, the thickness x (μm) of the organic thin film solar cell module in the center of a collection wire installation region 13 in the width direction of the collection wire 11, and the thickness y (μm) of the thin film solar cell module at a part of 5 mm outside from the outer peripheral edge of the organic thin film solar cell 9 satisfy a following formula: (x-y)≤90 (I).SELECTED DRAWING: Figure 2

Description

  The present invention relates to an organic thin film solar cell module.

  In recent years, transparent film solar cell modules using dye-sensitized solar cells, organic thin film solar cells, and the like have been developed. In particular, since a transparent film type solar cell module is lightweight and flexible, it is considered to be installed in a building or the like. For example, Patent Document 1 proposes a solar power generation film that is used by being attached to a window glass of a building as a product to which a transparent film type solar cell module is applied.

JP 2012-186310 A

  Since the solar power generation film as described above is installed and used near a human eye such as a window glass, the solar power generation film is required to have high designability. Therefore, it is thought that the finishing of the thin film solar cell module on the glass or the like and the handling of the solar cell module at the time of construction are important.

  A general wind film is attached to glass by a method called water sticking. This method of sticking with water is to stick the film on the glass surface by spraying water containing a small amount of neutral detergent on the adhesive surface and glass surface of the film with a sprayer, and then squeegeeing the film surface sequentially. Rub uniformly to bring the film and glass into close contact. As a result, water and air bubbles between the film and the glass are expelled from the end of the film, and a good bonding surface free from wrinkles and air bubbles can be obtained.

However, the present inventors created an organic thin film solar cell module having the same configuration as that of Patent Document 1 except that a collector wire was installed on the organic thin film solar cell element, and affixed to the window glass by water bonding. As a result, water bubbles between the glass and the organic thin-film solar cell module remained outside the installation location of the current collector.
This is because the thickness of the current collector installed portion increases corresponding to the thickness of the current collector, while the peripheral portion of the organic thin film solar cell module becomes thinner because the organic thin film solar cell elements are not stacked, resulting in the organic thin film. This is because the solar cell module has regions with different thicknesses, and water bubbles were not properly removed by the squeegee.

Furthermore, since an organic thin film solar cell module has a barrier layer in order to suppress deterioration of an organic thin film solar cell element, it is difficult for water bubbles to be removed by evaporation.
For these reasons, it was found that when the current collector was sealed together with the organic thin film solar cell element, the design after the organic thin film solar cell module was installed on glass deteriorated.

In order to solve the above-mentioned problems, the present inventors have intensively studied paying attention to the thickness of the barrier layer and the sealing layer. As a result, the organic thin film solar cell in the region where the current collector is further installed in the organic thin film solar cell element. The present invention finds that the above problem can be solved by making the difference between the thickness of the module and the thickness of the organic thin film solar cell module in the region where the organic thin film solar cell element is not sealed within a certain range. Was completed. That is, the gist of the present invention is as follows.

[1] A first gas barrier layer, a first sealing layer, an organic thin film solar cell element, a second sealing layer, and a second gas barrier layer are sequentially laminated, and between the first sealing layer and the organic thin film solar cell element. An organic thin film solar cell module having a collector wire electrically connected to the organic thin film solar cell element,
The thickness x (μm) of the organic thin film solar cell module at the center in the width direction of the current collection line in the current collection line installation region, and the thickness y (μm) of the thin film solar cell module 5 mm outside from the outer peripheral edge of the organic thin film solar cell element Satisfies the following formula (I): an organic thin film solar cell module.
(Xy) ≦ 90 (I)
[2] The organic thin film solar cell module according to [1], which sequentially includes a first gas barrier layer, a first sealing layer, an organic thin film solar cell element, a second sealing layer, a second gas barrier layer, and an adhesive layer.

  According to the present invention, it is possible to provide an organic thin-film solar cell module that maintains its design properties even after water application.

It is a schematic cross section which shows the layer structure of the organic thin-film solar cell module as one Embodiment of this invention. It is a schematic cross section which shows the layer structure of the organic thin-film solar cell module as one Embodiment of this invention. It is a schematic cross section which shows the organic thin film solar cell module as one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail. The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to these contents unless it exceeds the gist.

1. 1. Organic Thin Film Solar Cell Module 1.1 Configuration The layer configuration of the organic thin film solar cell module according to one embodiment of the present invention is as shown in the schematic cross-sectional view of FIG. It has the organic thin-film solar cell element 9, the 2nd sealing layer 3, and the 2nd gas barrier layer 1 in order. Moreover, when taking out electricity from an organic thin-film solar cell element, normally, the collector electrode for electricity extraction (not shown in FIG. 1) is connected to the upper electrode or lower electrode of each solar battery cell forming the organic thin-film solar cell. Is installed.
When using as a wind film, it is preferable to install a collector wire only on one surface of the organic thin-film solar cell element. That is, it is preferable that either a pair of current collectors is installed on the upper electrode of the organic thin film solar cell element, or any current collector is installed on the lower electrode of the organic thin film solar cell element. Is preferably installed on the upper electrode of the organic thin film solar cell element. That is, it is preferable to have a current collector electrically connected to the organic thin film solar cell element between the first sealing layer and the organic thin film solar cell element.

The first sealing layer 4 and the second sealing layer 3 (hereinafter, the first sealing layer and the second sealing layer may be collectively referred to as a sealing layer) seal the organic thin film solar cell element 9. The organic thin-film solar cell element 9 is usually completely covered with the first sealing layer 4 and the second sealing layer 3. It is sealed by being provided. The first gas barrier layer 2 and the second gas barrier layer 1 (hereinafter, the first gas barrier layer and the second gas barrier layer may be collectively referred to as a gas barrier layer) and the positional relationship and relative size of the sealing layer are not particularly limited. Usually, the sealing layer and the gas barrier layer are laminated with the same size and the same shape, with the ends aligned, or the gas barrier layer covers the entire surface of the sealing layer and the gas barrier layer is sealed. Laminated larger than the layer. In order to prevent deterioration due to moisture or oxygen and maintain the performance of the solar cell element over a long period of time, the end surface of the gas barrier layer is set so that the distance between the end surface of the gas barrier layer and the end surface of the solar cell element substrate is 5 mm or more. Is preferably placed outside the end face of the solar cell element substrate.
Moreover, it is preferable that the organic thin film solar cell module in this embodiment contains the adhesion layer for sticking to a construction target object in the outermost layer, and is installed in a window etc. by this adhesion layer.

For example, as shown in FIG. 2, the adhesive layer 10 is provided on the second gas barrier layer 1, and the first gas barrier layer 2, the first sealing layer 4, the organic thin film solar cell element 9, the second sealing layer 3, the second It can be set as the structure which has the gas barrier layer 1 and the adhesion layer 10 one by one. A conventionally known pressure-sensitive adhesive can be used for the pressure-sensitive adhesive layer 10, but an acrylic pressure-sensitive adhesive is preferably used from the viewpoint of weather resistance and transparency. The adhesive layer can be provided by a known method on the outermost layer on the substrate side (light receiving surface) or the photoelectric conversion layer side (non-light receiving surface) of the organic thin film solar cell element used in the organic thin film solar cell module. From the viewpoint of power generation efficiency of the thin-film solar cell element, it is preferable to provide the outermost layer on the substrate side (light-receiving surface) of the organic thin-film solar cell element.
The adhesive layer 10 is attached to a construction object such as a glass window, so that the organic thin film solar cell module is installed on the construction object.

  The organic thin film solar cell module preferably has translucency. As for the translucency of the organic thin film solar cell module, the visible light transmittance measured by a method according to JIS R 3106 is usually 3% or more, preferably 5% or more, more preferably 8% or more, still more preferably 10% or more. Particularly preferably, it is 20% or more, usually 80% or less, preferably 60% or less, more preferably 50% or less. It is preferable that it is at least the above lower limit in that the daylighting property can be improved. It is preferable at the point which can improve electric power generation efficiency by being below the said upper limit.

  The organic thin film solar cell module having translucency is, for example, an organic thin film solar cell element having translucency by using a transparent electrode as an electrode of the organic thin film solar cell element, and an organic thin film other than the organic thin film solar cell element. It is realizable by making the structural member of a solar cell module into the member which has translucency.

In the present embodiment, the thickness x (μm) of the organic thin-film solar cell module in the center in the width direction of the collector line in the collector-installation region and the thickness of the thin-film solar cell module 5 mm outside from the outer peripheral edge of the organic thin-film solar cell element. The depth y (μm) satisfies the following formula (I).
(Xy) ≦ 90 (I)

  In FIG. 2, the current collection line installation region in the present embodiment refers to the left and right ends of the current collection line 11, that is, the surface parallel to the thickness direction of the organic thin film solar cell module in contact with the outer edge of the current collection line. It is a region on the surface of the organic thin film solar cell module surrounded by a line intersecting with the surface, and is a region indicated by a chain line 13. Specifically, the thickness x (μm) of the organic thin film solar cell module at the center in the width direction of the current collection line in the current collection line installation region 13 is, for example, an organic thin film solar cell at the position of BB ′ dashed line in FIG. The thickness of the module. The thickness y (μm) of the thin-film solar cell module 5 mm outside from the outer peripheral end of the organic thin-film solar cell element (the position of the C—C ′ two-dot chain line) is the organic thin-film solar cell module from the end face of the organic thin-film solar cell element The thickness of the organic thin-film solar cell module at the position of the DD ′ dotted line in FIG. In addition, the AA 'chain line in a figure shows the center part of an organic thin film solar cell module.

The thickness of the organic thin film solar cell module is the shortest distance between the surface on the second gas barrier layer side and the surface on the first gas barrier layer side with respect to the organic thin film solar cell element of the organic thin film solar module. It means the length of the organic thin film solar module in the normal direction with respect to the surface on the two gas barrier layer side. The thickness of the organic thin film solar cell module can be measured using, for example, a contact thickness meter (KG601A, manufactured by Anritsu Corporation).
In the present embodiment, the above formula (I) is a range in which water and bubbles can be easily removed from between the organic thin film solar cell module and the construction object when the organic thin film solar cell module is attached to the construction object by water adhesion. Is specified.

  When affixing a wind film to a construction object such as glass, in order to remove water and air bubbles between the wind film and the glass, rubbing with a squeegee while applying pressure uniformly from the center of the film surface to the outside. Therefore, it is necessary to adhere the film and the glass. In the present embodiment, the organic thin film solar cell module can have a step on its surface due to the sealed collector wire or organic thin film solar cell element. When there is a step on the surface of the organic thin film solar cell module, the pressure of the squeegee becomes weak, especially in the step region where the squeegee moves from a thick part to a thin part of the organic thin film solar cell module. It is difficult to apply uniform pressure to the module, and water and bubbles cannot be expelled.

  The above formula (I) defines the upper limit of the difference between the thickness x (μm) of the thickest portion and the thickness y (μm) of the thinnest portion of the organic thin film solar cell module. That is, in the organic thin-film solar cell module according to the configuration of the present embodiment, the central portion (corresponding to x) of the current collection line installation region in the current collection line installation region is usually the thinnest place as the thinnest place. This defines a position (corresponding to y) 5 mm from the outer peripheral edge of the organic thin film solar cell element toward the module edge.

  In this embodiment, (xy) (μm) is 90 or less, preferably 80 or less, more preferably 70 or less, still more preferably 60 or less, and particularly preferably 50 or less. The lower limit is not limited and is ideally zero, but since the current collector has a thickness, the value of (xy) is too small that the organic thin-film solar cell element is pressed against the current collector Usually 0.5 or more, preferably 1 or more, more preferably 3 or more, more preferably 5 or more.

  The range of x (μm) is not limited, but is usually 200 or more, preferably 300 or more, more preferably 330 or more, and still more preferably 340 or more, in order to prevent the organic thin film solar cell module from being broken. 350 or more is most preferable. On the other hand, in order to obtain a flexible solar cell, x (μm) is usually 2000 or less. However, it is easy to make (xy) (μm) small and to apply pressure uniformly to the organic thin film solar cell module during squeegee construction, between the organic thin film solar cell module and the glass that is the construction object. X (μm) is preferably 900 or less, more preferably 700 or less, and particularly preferably 500 or less.

  The range of y (μm) is not particularly limited as long as (xy) (μm) is 90 or less, but is usually 130 or more, preferably 230 or more, more preferably 280 or more, and 320 or more. Is most preferred. The organic thin film solar cell module has a large recess in the area within 5 mm from the outer peripheral edge of the organic thin film solar cell element toward the module end, and pressure can be applied uniformly during squeegee construction. Water and air bubbles between the module and the construction object can be removed. y (μm) can be controlled, for example, by making the thicknesses of the first barrier layer and the second barrier layer thicker than the sum of the organic thin film solar cell element and the current collector.

By being below the above upper limit, when the surface of the organic thin film solar cell module is rubbed with the squeegee sequentially while applying pressure uniformly, the pressure is evenly applied to the step portion of the surface of the organic thin film solar cell module. Water and air bubbles between the organic thin-film solar cell module and the glass that is the object of construction can be expelled efficiently. Moreover, by being more than the said minimum, the choice of the kind of electrical power collection line used for an organic thin film solar cell module increases. When increasing the voltage and / or current to be extracted from the organic thin film solar cell element, it is necessary to increase the thickness of the current collector. Therefore, increasing the options for the current collector increases the degree of freedom in designing the organic thin film solar cell module. be able to. Moreover, since the freedom degree of the lamination conditions at the time of manufacturing an organic thin film solar cell module goes up, it is preferable. Furthermore, the freedom degree of the organic thin-film solar cell element arrangement | sequence within an organic thin-film solar cell module can also be raised.

  The value of (xy) (μm) is, for example, the thickness of the sealing layer, the current collector, and / or the organic thin film solar cell element, or the heat applied in the stacking conditions of the organic thin film solar cell module It can be controlled by adjusting the pressure. For example, the thickness of the second sealing layer is made thicker than the thickness of the current collector connected to the organic thin film solar cell element, or the sum of the thicknesses of the first sealing layer and the second sealing layer is set to the organic thin film By making it larger than the sum of the thicknesses of the solar cell element and the collector line, the upper limit can be made below.

Hereinafter, the structural member of the organic thin film solar cell module of this invention is demonstrated.
1.2 Component 1.2.1 Gas barrier layer (first gas barrier layer and second gas barrier layer)
The gas barrier layer is a layer that prevents permeation of water and oxygen.
By the gas barrier layer, the organic thin film solar cell element can be prevented from being deteriorated by moisture or oxygen, and the performance can be maintained over a long period of time. Since design properties such as light transmittance and transparency can be improved in addition to the long-term durability described above, it is more preferable that the gas barrier layer also serves as a protective layer described later.

  Organic thin-film solar cell elements tend to be deteriorated by moisture and oxygen. In particular, transparent electrodes such as ZnO: Al and organic semiconductor layers constituting organic thin-film solar cells tend to be deteriorated by moisture and oxygen. Therefore, by covering the organic thin film solar cell element with the gas barrier layer, the organic thin film solar cell element can be protected from water and oxygen, and the power generation performance can be kept high.

The degree of moisture-proof capability required for the gas barrier layer is that the water vapor permeability per unit area (1 m ² ) per day is 1 × 10 ⁻¹ g / m ² / day or less in a 40 ° C. and 90% RH environment. 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. As the permeation of water vapor is suppressed, deterioration due to the reaction of the organic thin film solar cell element and the transparent electrode such as ZnO: Al of the element with moisture is suppressed, so that the lifetime is extended by maintaining the power generation efficiency.

The degree of oxygen permeability required for the gas barrier layer is such that the oxygen permeability per day of a unit area (1 m ² ) at a thickness of 100 μm in an environment of 25 ° C. is 1 × 10 ⁻¹ cc / m ² / day / It is preferably atm or less, more preferably 1 × 10 ⁻² cc / m ² / day / atm or less, even more preferably 1 × 10 ⁻³ cc / m ² / day / atm or less, It is particularly preferably 1 × 10 ⁻⁴ cc / m ² / day / atm or less, particularly preferably 1 × 10 ⁻⁵ cc / m ² / day / atm or less, and 1 × 10 ⁻⁶ cc / m. ² / day / atm or less is particularly preferable. The deterioration due to oxidation of the organic thin-film solar cell element and the transparent electrode such as ZnO: Al of the element is suppressed as oxygen does not permeate.

  By applying such a gas barrier layer, it becomes easy to implement an organic thin film solar cell module utilizing the excellent properties of the organic solar cell element.

Further, the gas barrier layer is preferably one that transmits visible light from the viewpoint of not hindering light absorption of the organic thin film solar cell element. For example, the transmittance of visible light (wavelength 360 to 830 nm) measured by a method according to JIS R 3106 is usually 60% or more, preferably 70% or more, more preferably 75% or more, still more preferably 80% or more, Among them, preferably 85% or more, particularly preferably 90% or more, particularly preferably 95% or more, and particularly preferably 97% or more. This is to convert more sunlight into electrical energy.

  Furthermore, the gas barrier layer preferably has a low haze from the viewpoint of design properties such as a sense of unity with the construction object and appearance. For example, the haze value when using a D65 light source defined by JIS K 7136 is usually 10 or less, preferably 5 or less, more preferably 2 or less, and even more preferably 1 or less.

  Further, since the organic thin film solar cell module is often heated by receiving light, it is preferable that the gas barrier layer also has heat resistance. From this viewpoint, the melting point of the constituent material of the gas barrier layer is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and usually 350 ° C. or lower, preferably 320 ° C. or lower, more preferably 300 It is below ℃. By increasing the melting point, it is possible to reduce the possibility that the gas barrier layer melts and deteriorates when the organic thin film solar cell module is used.

  The specific configuration of the gas barrier layer is arbitrary as long as the organic thin-film solar cell element 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 layer increases, it is preferable to use an appropriate material in consideration of these points comprehensively. Specifically, a structure in which an inorganic layer is laminated on a resin base material is preferable.

  The material for forming the resin substrate is not particularly limited. For example, a polyolefin resin such as a homopolymer or copolymer such as ethylene, propylene, or butene; an amorphous polyolefin resin such as a cyclic polyolefin; polyethylene terephthalate Polyester resins such as (PET) and polyethylene naphthalate (PEN); Polyamide resins such as nylon 6, nylon 66, nylon 12, copolymer nylon; ethylene-vinyl acetate copolymer partial hydrolyzate (EVOH), polyimide Resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyether ether ketone resin, polycarbonate resin, polyvinyl butyral resin, polyarylate resin, fluororesin, acrylic resin, biodegradable Examples thereof include resins. In addition, the resin base material may be formed with 2 or more types of materials, and may be a laminated structure. Among these, from the viewpoint of film properties, polyester resins are preferable, and polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) is particularly preferable.

The material for forming the inorganic layer is not particularly limited, but silicon, aluminum, magnesium, zinc, tin, nickel, titanium, or oxides, carbides, nitrides, oxycarbides, oxynitrides, oxycarbonitrides of these Products, diamond-like carbon, or a mixture thereof. Moreover, the inorganic layer may be formed of two or more kinds of materials, or may have a laminated structure. Among these, in order to prevent current leakage, the material constituting the inorganic layer is silicon oxide, silicon oxycarbide, silicon oxynitride, silicon oxycarbonitride, aluminum oxide, aluminum oxycarbide, aluminum oxynitride, silicon nitride, Aluminum nitride, diamond-like carbon and mixtures thereof are preferred. Further, among these, silicon oxide, silicon oxycarbide, silicon oxynitride, silicon oxycarbonitride, silicon nitride, aluminum oxide, aluminum oxycarbide, aluminum oxynitride, and aluminum nitride are able to stably maintain high moisture resistance. And mixtures thereof are particularly preferred. The inorganic layer may be composed of a plurality of inorganic materials. Moreover, you may have a some inorganic layer. Also in this case, the plurality of inorganic layers may be formed of the same material or may be formed of different materials. In addition, from the viewpoint of the design properties of the organic thin film solar cell module, the optical physical properties are preferably more transparent,
Silicon oxide, silicon oxynitride, and silicon nitride are preferable, and silicon oxide is particularly preferable.

Among the above, a preferable gas barrier layer includes a film obtained by vacuum-depositing silicon oxide (SiOx) on a base film such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN).
Note that the gas barrier layer may be formed of one kind of material or two or more kinds of materials. The gas barrier layer may be a single layer or a laminate of two or more layers.

  The thickness of the gas barrier layer is not particularly defined, but is usually 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, and usually 200 μm or less, preferably 180 μm or less, more preferably 150 μm or less. Increasing the thickness tends to increase gas barrier properties, and decreasing the thickness tends to increase flexibility and improve visible light transmittance.

The storage modulus of the gas barrier layer at 25 ° C. and a frequency of 10 Hz is not particularly limited, but is 1.0 × 10 ⁸ Pa or more, preferably 3.0 × 10 ⁸ Pa or more, on the other hand, 6.0 × 10 ⁹ Pa or less. In the case of 4.0 × 10 ⁹ Pa or less, the present invention can exert the effect more remarkably for the following reasons. When the storage elastic modulus of the gas barrier layer is less than or equal to the above upper limit value, the pressure of the squeegee during squeegee tends to have a greater effect on the organic thin film solar cell element, and the storage elastic modulus of the gas barrier layer has the above lower limit value. When it is below, delamination in the organic thin-film solar cell element tends to occur due to stress when the thin-film solar cell module is bent. Therefore, when the gas barrier layer is used, the present invention can exhibit the effect more remarkably.

  As long as the gas barrier layer can be coated and protected from moisture and oxygen by covering the organic thin film solar cell element, the formation position is not limited, but both sides of the organic thin film solar cell element, specifically, the light receiving surface side (FIG. 1). It is preferable to cover the lower surface) and the surface opposite to the light receiving surface (the upper surface in FIG. 1). This is because in the thin film solar cell module, the light receiving surface side surface and the surface opposite to the light receiving surface are often formed in a larger area than the other surfaces. In the present embodiment, the gas barrier layer is disposed so as to cover the light receiving surface side of the organic thin film solar cell element and the surface opposite to the light receiving surface.

  There are no particular restrictions on the positional relationship and relative size of the gas barrier layer and the sealing layer, but usually the sealing layer and the gas barrier layer are laminated with the same size and the same shape and with the ends aligned. Alternatively, the gas barrier layer covers the entire surface of the sealing layer, and the gas barrier layer is laminated larger than the sealing layer. In order to prevent deterioration due to moisture or oxygen and maintain the performance of the solar cell element over a long period of time, the distance between the end face of the gas barrier layer and the end face of the solar cell element substrate is 5 mm or more, preferably 10 mm or more. Further, it is preferable that the end face of the gas barrier layer is disposed outside the end face of the solar cell element substrate.

  In addition, the gas barrier layer has a hard coat layer to prevent damage when handling the thin film solar cell module, to prevent damage due to a squeegee when applying water to a construction object, and to improve the smoothness of the gas barrier layer. May be provided.

As this hard coat layer, conventionally known ones can be used, such as an ultraviolet curable resin; an electron beam curable resin; an alkoxysilane hydrolytic condensation resin; a melamine resin; a (meth) acrylate alcohol-modified polyfunctional compound; Examples include layers made of acrylic resins such as trimethylolpropane (meth) acrylate, tripropylene glycol diacrylate, pentaerythritol triacrylate, 1,6 hexanediol (meth) acrylate, but are not limited thereto. . The hard coat layer preferably has a pencil hardness of 2H or higher, more preferably 3H or higher. Moreover, it is preferable that the film thickness is 1-10 micrometers. If it is less than 1 μm, the effect of scratch resistance may not be sufficient, and if it is 10 μm or more, the gas barrier layer may curl due to curing shrinkage of the hard coat layer.

1.2.2 Sealing layer (first sealing layer and second sealing layer)
In an embodiment of the present invention, an organic thin film solar cell module is manufactured by connecting an organic thin film solar cell element and a collector wire. At least the organic thin film solar cell element is sealed with a sealing material, and the organic thin film solar cell element is obtained. Is preferably protected. The organic thin-film solar cell element is sealed in order to reinforce the organic thin-film solar cell element and increase impact resistance.

  The sealing layer preferably has a high bending strength from the viewpoint of maintaining the strength of the organic thin film solar cell module. The specific strength is related to the strength of the layers other than the sealing material and is difficult to define in general, but the entire organic thin-film solar cell module has good bending workability and causes peeling of the bent portion. It is desirable to have such bending strength.

  Moreover, when a sealing layer is used for the light-receiving surface side of an organic thin-film solar cell element, what transmits visible light from a viewpoint which does not prevent light absorption is preferable. For example, the transmittance of visible light (wavelength 360 to 830 nm) measured by a method according to JIS R 3106 is usually 75% or more, preferably 80% or more, more preferably 85% or more in a single sealing layer. More preferably, it is 90% or more, more preferably 95% or more, and particularly preferably 97% or more. This is to convert more sunlight into electrical energy.

  Further, the sealing layer preferably has a low haze from the viewpoint of design properties such as a sense of unity with the construction object and appearance. For example, the haze value when using a D65 light source defined by JIS K 7136 is usually 15 or less, preferably 10 or less, more preferably 5 or less, and even more preferably 2 or less in a single sealing layer.

  On the other hand, when a sealing material is used on the side opposite to the light receiving surface of the organic thin film solar cell element, it is not always necessary to transmit visible light and may be opaque, but it is pasted on a transparent construction object such as a window glass. In the case, it is preferable to have the same visible light transmittance and haze as those on the light-receiving surface side of the organic thin-film solar cell element.

  Furthermore, since the organic thin film solar cell module is often heated by receiving light, the sealing layer preferably has heat resistance. From this viewpoint, the melting point of the constituent material of the sealing layer is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and usually 350 ° C. or lower, preferably 320 ° C. or lower, more preferably It is 300 degrees C or less. By increasing the melting point, it is possible to prevent the sealing layer from melting and deteriorating when the organic thin film solar cell module is used.

Further, from the viewpoint of suppressing deformation of the organic thin film solar cell module itself when the organic thin film solar cell module is used, when the melting point is present in the sealing layer, the melting point of the sealing layer may be 50 ° C. or higher. Preferably, it is 80 ° C. or higher, and more preferably 100 ° C. or higher. On the other hand, from the viewpoint of preventing the organic thin-film solar cell module from warping and undulation due to the large thermal expansion and contraction of the members other than the sealing layer during the production of the solar cell module, the melting point of the sealing layer Is preferably 250 ° C. or lower, more preferably 200 ° C. or lower, more preferably 180 ° C. or lower, particularly preferably 160 ° C. or lower, and particularly preferably 140 ° C. or lower. . In addition, when the sealing layer does not have a melting point, in order to ensure sufficient adhesion and adhesion with the organic thin-film solar cell element, the substrate, the gas barrier layer, and other layers, the adhesive layer has adhesiveness in the above temperature range. It is preferable to have.

  When the organic thin-film solar cell module has both the first sealing layer and the second sealing layer, the lower limit of the sum of the thicknesses of the first sealing layer and the second sealing layer is sealed. Although it is not limited from the viewpoint of the remaining squeegee trace of the stop layer, it is usually 40 μm or more, preferably 60 μm or more, more preferably 80 μm or more, and usually 800 μm or less, preferably 400 μm or less, more preferably 300 μm or less, more preferably 200 μm or less. Increasing the thickness tends to increase the strength (koshi) of the entire organic thin-film solar cell module, and decreasing the thickness tends to increase flexibility and improve visible light transmittance. For this reason, it is desirable to set it as the said range as a range which has both advantages. On the other hand, when deviating from the above range, if the sealing layer is too thick, water bubbles remain between the organic thin-film solar cell module and the construction object due to poor workability during squeegee construction when applying water, If the sealing layer is too thin, the organic thin-film solar cell element may be damaged by the squeegee pressure, and the power generation performance of the element may be reduced. In addition, the thickness of the above-mentioned sealing layer and the thickness of the sealing layer described below are cross-sectional observations using a microscope of the cut surface when the organic thin film solar cell module was cut after the organic thin film solar cell module was created. The thickness obtained from the results is shown.

  Each thickness of the first sealing layer or the second sealing layer is not particularly defined, but is usually 20 μm or more, preferably 30 μm or more, more preferably 40 μm or more, further preferably 60 μm or more, and usually 400 μm. Hereinafter, it is preferably 200 μm or less, more preferably 150 μm or less, and still more preferably 100 μm or less. Increasing the thickness can prevent damage to the organic thin-film solar cell element, and decreasing the thickness tends to improve the transmittance of visible light. For this reason, it is desirable to set it as the said range as a range which has both advantages.

  Although the ratio T1 / (T1 + T2) of the thickness T1 of the first sealing layer to the total thickness of the thickness T1 of the first sealing layer and the thickness T2 of the second sealing layer is not particularly defined, it is usually set to 0.8. It is in the range of 3 to 0.7, preferably in the range of 0.4 to 0.6, more preferably 0.5. When the thickness ratio is within this range, the organic thin-film solar cell module can be handled easily, and the remaining water bubbles at the time of water application can be reduced. It becomes possible to suppress the curvature of an organic thin-film solar cell module especially by being below an upper limit, and workability improves.

  The material constituting the sealing layer is not particularly limited, and heat such as a vinyl acetate-ethylene copolymer composition containing a crosslinking agent, a thermosetting resin such as polyurethane and epoxy resin, a polyolefin resin, a polyester, and an acrylic resin. It may be an elastomeric resin such as a plastic resin, butyl rubber, or silicone rubber, or the above composite. Among them, the material constituting the first sealing layer is an epoxy resin, an acrylic resin, or a polyolefin resin because it is easy to control the storage elastic modulus and the bending elastic modulus depending on the viewpoint of transparency and the material composition. Is preferred.

  The sealing layer has a temperature capable of sealing of usually 50 ° C. or higher, preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and usually 250 ° C. or lower, preferably 200 ° C. or lower, more preferably 180 ° C. or lower, still more preferably. Is 160 ° C. or lower, particularly preferably 140 ° C. or lower. When the sealing layer contains the thermosetting resin, it is preferable in that the organic thin film solar cell module is not easily deformed even when exposed to high temperatures. Furthermore, when the sealing layer contains a thermosetting resin such as an epoxy resin, it is preferable because the sealing layer, which is a thermosetting resin, can be simultaneously cured when the organic thin film solar cell module is sealed.

  The curing temperature of the thermosetting resin contained in the sealing layer (that is, the curing temperature of the sealing material containing the thermosetting resin) is usually 50 ° C. or higher, preferably 100 ° C. or higher, and usually 250 ° C. or lower, preferably Is 200 ° C. or lower, more preferably 180 ° C. or lower, still more preferably 160 ° C. or lower, and particularly preferably 140 ° C. or lower.

Note that the sealing layer may be formed of one kind of material or two or more kinds of materials. The sealing layer may be a single layer or a laminate of two or more layers.
The sealing layer is usually provided so as to sandwich the organic thin film solar cell element.
Further, the sealing layer may be provided with functions such as ultraviolet blocking, heat blocking, conductivity, antireflection, antiglare, light diffusion, light scattering, wavelength conversion, and gas barrier properties. In particular, the organic thin film solar cell element may be deteriorated by water or oxygen, and may be deteriorated by ultraviolet rays from sunlight. Therefore, it is preferable to have a gas barrier property and an ultraviolet blocking function.
As a method for imparting such a function, a layer having a function may be laminated on the sealing layer by coating film formation or the like, or a material that exhibits a function may be dissolved and dispersed in the sealing layer. You may make it contain.

Examples of the gas barrier property include those satisfying the following water vapor permeability and oxygen permeability.
As the water vapor transmission rate, the water vapor transmission rate Pd when the sealing material is 100 μm thick is usually 10 ⁻¹ g / m ² / day or less, preferably 10 ⁻² g / m ² / day, in an environment of 40 ° C. and 90% RH. Hereinafter, it is more preferably 10 ⁻³ g / m ² / day or less, still more preferably 10 ⁻⁴ g / m ² / day or less. The water vapor transmission rate is measured in an environment of 40 ° C. and 90% RH by a measurement using an apparatus equipped with a humidity sensor, an infrared sensor, and a gas chromatograph according to JIS K7129, or by a cup method (JIS Z0208).

As the oxygen permeability, for example, generally, the oxygen permeability per day of a unit area (1 m ² ) at a thickness of 100 μm in a 25 ° C. environment is usually 1 cc / m ² / day / atm or less. , 1 is preferably × 10 ^-1 or less ^{cc / m 2 / day / atm} , more preferably not more than ^{1 × 10 -2 cc / m 2} / day / atm, 1 × 10 -3 cc / m ² / day / atm or less is more preferable, 1 × 10 ⁻⁴ cc / m ² / day / atm or less is particularly preferable, and 1 × 10 ⁻⁵ cc / m ² / day / atm or less. It is particularly preferred. There is an advantage that the deterioration due to the oxidation of the element can be suppressed as the oxygen does not permeate. The oxygen permeability can be measured with an apparatus based on a differential pressure method according to JIS K7126A, or an apparatus equipped with an infrared sensor and a gas chromatograph based on an isobaric method according to JIS K7126B.

The sealing layer is usually formed by laminating a sealing material and an organic thin film solar cell element, preferably by laminating a laminate of a gas barrier layer and a sealing layer and an organic thin film solar cell element. Is done. The step of laminating the sealing material on the organic thin-film solar cell element may be performed after the step of installing the current collector on the organic thin-film solar cell element (current collector installation step), or may be performed before the current collector installation step. Good.
In the case of having a step of laminating the sealing material on the organic thin-film solar cell element after the current collector installation step, the sealing material is laminated on the organic thin-film solar cell element on which the current collector is installed, A slit can be formed at a location where the electric wire is taken out, and the current collecting wire can be taken out from the slit. The number of locations where the collector wire is connected to the upper electrode of the organic thin film solar cell element is arbitrary as long as it is one or more. In the case where a plurality of organic thin film solar cell elements are connected in series, a collector wire may be connected to the organic thin film solar cell element so that a desired potential can be taken out.

In the case of having a step of laminating the sealing material on the organic thin film solar cell element before the collecting wire installation step, a slit is formed in the sealing material after sealing, and the upper electrode of the organic thin film solar cell element in the slit Is in an exposed state. And what is necessary is just to connect the upper electrode and collector wire of the position of a slit. Moreover, by providing a slit at a specific position in advance in the sealing material before sealing, the labor of forming the slit after sealing can be saved. Providing slits in advance in this way makes it possible to eliminate the possibility of damage to the organic thin film solar cell element that occurs when the slits are formed after sealing.

1.2.3 Organic thin-film solar cell element An organic thin-film solar cell element usually has a structure in which a lower electrode, an organic photoelectric conversion layer, and an upper electrode are sequentially laminated on a substrate. The organic thin film solar cell element generally has a total film thickness of layers constituting the organic thin film solar cell element including the element substrate of 150 μm or less, and particularly the film thickness of the portion excluding the element substrate is 30 μm or less. It is preferable that

  The organic thin film solar cell element used for the organic thin film solar cell module has characteristics that are strong in handling properties at the time of water application and bending of the organic thin film solar cell module. The organic thin film solar cell element is preferable in that the organic photoelectric conversion layer can be produced by coating and has excellent design properties. By using the organic photoelectric conversion layer, the productivity of the organic thin film solar cell element is particularly excellent, and it is particularly preferable because it meets the object of the present invention.

1.2.3.1 Substrate The substrate is a member that supports the organic thin-film solar cell element. The material of the substrate is not particularly limited as long as the present invention can be applied, and known materials such as inorganic materials, organic materials, paper materials, and composite materials can be used. Specifically, inorganic materials such as quartz, glass, sapphire or titania; polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, fluororesin, vinyl chloride or Polyolefins such as polyethylene; Organic materials such as cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate, polynorbornene or epoxy resin; Paper materials such as paper or synthetic paper; Metals such as stainless steel, titanium or aluminum In addition, a composite material such as a material whose surface is coated or laminated in order to impart insulating properties may be used. Of these, resin substrates using organic materials can provide transparency to the substrate, so both superstrate and substrate structures can be created, and translucent see-through solar cells can be created. Is preferable in that it is possible.

Among these, the substrate is preferably a flexible (flexible) substrate. Because the substrate is flexible, the organic thin film solar cell element can be manufactured by a roll-to-roll method, and the degree of freedom of installation of the organic thin film solar cell element is improved. Moreover, an organic thin film solar cell module can be made flexible. Having flexibility means, for example, that the substrate is not broken (plastically deformed) even when the substrate is bent at a curvature radius of 170 mm.
Among the above materials, the flexible substrate material is preferably an organic material, a paper material, or a composite material, more preferably an organic material or a composite material, and particularly preferably an organic material.

  The organic material usually has Tm (melting temperature) and Tg (glass transition temperature), but the deterioration of the appearance due to deformation of the substrate is suppressed by sealing the organic thin film solar cell element at less than Tm, preferably less than Tg. be able to.

When the substrate is a resin substrate, the glass transition temperature (Tg) of the resin substrate is usually 30 ° C. or higher, preferably 50 ° C. or higher, usually 400 ° C. or lower, preferably 300 ° C. or lower, more preferably 200 ° C. or lower, More preferably, it is 160 degrees C or less. When the glass transition temperature (Tg) is in the above range, it is easy to perform molding when producing a resin substrate, and deformation is less likely to occur during the production of an organic thin film solar cell.
The glass transition temperature in the present specification is a value obtained by differential scanning calorimetry (DSC) defined in JIS K-7121 1987 “Method for measuring plastic transition temperature”.

  Although there is no restriction | limiting in the thickness of a board | substrate, it is 5 micrometers or more normally, Preferably it is 20 micrometers or more, and is 20 mm or less normally, Preferably it is 10 mm or less. It is preferable that the thickness of the substrate is 5 μm or more because the possibility that the strength of the organic thin film solar cell element is insufficient is reduced. It is preferable that the thickness of the substrate is 20 mm or less because the cost is suppressed and the weight does not increase. When the material of the substrate is glass, the thickness is usually 0.01 mm or more, preferably 0.1 mm or more, and is usually 1 cm or less, preferably 0.5 cm or less. It is preferable that the thickness of the substrate is 0.01 mm or more because mechanical strength is increased and cracking is difficult. Moreover, it is preferable that the thickness of the substrate is 0.5 cm or less because the weight does not increase.

The storage elastic modulus of the substrate at 25 ° C. and a frequency of 10 Hz is not particularly limited, but when the thickness of the substrate is 5 μm or more and 20 mm or less, the coefficient of restitution against damage to the organic thin film solar cell element due to external stress is suppressed. Therefore, it is preferably 6.0 × 10 ⁹ Pa or less, and particularly preferably 4.0 × 10 ⁹ Pa or less. On the other hand, in order to prevent damage to the organic thin film solar cell element that may occur during handling of the substrate during the production of the organic thin film solar cell module, the storage elastic modulus at 25 ° C. and a frequency of 10 Hz of the substrate at the film thickness is 1. It is preferably 0 × 10 ⁸ Pa or more, and particularly preferably 3.0 × 10 ⁸ Pa or more.

Although there is no restriction | limiting in the length of a board | substrate, Usually, 10 cm or more, Preferably it is 1 m or more, More preferably, it is 10 m or more, More preferably, it is 50 m or more, Most preferably, it is 100 m or more. The upper limit is usually 10 km or less, preferably 5 km or less, more preferably 1 km or less, still more preferably 500 m or less.
When manufactured by a roll-to-roll method, it is usually 10 m or more, preferably 20 m or more, more preferably 50 m or more, still more preferably 100 m or more, and particularly preferably 200 m or more. Although an upper limit in particular is not restrict | limited, Usually, it is 10 km or less, Preferably it is 5 km or less, More preferably, it is 1 km or less. By setting the length within this range, efficient production by a roll-to-roll system can be performed. In the roll-to-roll method, since it takes time to switch the roll, in order to reduce the time loss due to the switching of the roll, it is preferable that the substrate of one roll is as long as the manufacturing apparatus allows. On the other hand, it should be noted that handling becomes difficult when the roll becomes heavy.

1.2.3.2 Electrodes (lower and upper electrodes)
The organic thin film solar cell element has a pair of electrodes including a lower electrode and an upper electrode. In the present invention, the lower electrode means an electrode arranged on the substrate side, and the upper electrode means an electrode arranged above the lower electrode when the substrate is the bottom. These electrodes have a function of collecting holes and electrons generated by light absorption. Specifically, of the pair of electrodes, one electrode is an electrode suitable for collecting holes (hereinafter sometimes referred to as an anode), and the other electrode is an electrode suitable for collecting electrons ( Hereinafter, it may be described as a cathode). The lower electrode may be an anode, the upper electrode may be a cathode, the lower electrode may be a cathode, and the upper electrode may be an anode. Any one of the lower electrode and the upper electrode may be translucent, and both may be translucent.

In the present invention, the term “translucent” means that the solar ray transmittance, that is, the proportion of sunlight that transmits light having a wavelength of 360 to 830 nm, is usually 40% or more, preferably 50% or more, more preferably. Is 60% or more, more preferably 70% or more.
In addition, it is preferable that the transparent electrode has a solar ray transmittance of usually 70% or more in order to allow light to reach the organic photoelectric conversion layer through the transparent electrode.
These light transmittances are values measured in accordance with JIS 7375: 2008.

The lower electrode and the upper electrode can be formed of a conductive material,
For example, metals such as platinum, gold, silver, aluminum, chromium, nickel, copper, titanium, magnesium, calcium, barium, sodium or alloys thereof; metals such as nickel oxide, indium oxide, tungsten oxide, tin oxide, zinc oxide And oxides or composite oxides such as indium-tin oxide (ITO), indium-zinc oxide (IZO), and indium-tungsten oxide (IWO).

  Especially, it is preferable to use a material with a large work function for the anode. On the other hand, it is preferable to use a material having a small work function for the cathode. By optimizing the work function, there is an advantage of favorably collecting holes and electrons generated by light absorption. In addition, when providing a buffer layer in an organic thin film solar cell element so that it may mention later, a lower electrode and an upper electrode can also be formed using the material of the same work function by adjusting the work function of a buffer layer.

Note that as described above, at least one of the pair of electrodes has translucency, but at least the electrode on the light-receiving surface side has translucency and is preferably transparent. However, the electrode is not necessarily transparent if it does not significantly adversely affect the power generation performance. If the material of a transparent electrode is mentioned, said metal oxide, composite oxide, a metal thin film, etc. will be mentioned, A metal oxide and composite oxide are preferable. Further, the light transmittance of the upper electrode is preferably 80% or more, excluding loss due to partial reflection at the optical interface, considering the power generation efficiency of the organic thin film solar cell element.
In this case, it is preferable that the lower electrode formed on the substrate side has translucency. That is, by using a metal or alloy having a predetermined thickness as the upper electrode, it is easy to install the current collector with respect to the upper electrode, and the resistance between the current collector and the electrode can be easily lowered.

The materials for the lower electrode and the upper electrode may be used alone or in combination of two or more in any combination and ratio. Further, each of the lower electrode and / or the upper electrode may be a single layer or a stacked layer. In particular, the translucent electrode is preferably formed of a metal oxide or a composite oxide among the above materials, but in order to improve conductivity, the translucency is not lost. A structure in which a thin metal layer is stacked on these oxide layers may be employed.
In addition, when either one of an upper electrode and a lower electrode is translucent, it is preferable that the lower electrode formed in the board | substrate side has translucency. That is, by using a metal or alloy having a predetermined thickness as the upper electrode, it is easy to install the current collector with respect to the upper electrode, and the resistance between the current collector and the electrode can be easily lowered.
Moreover, this embodiment can be used conveniently when the electrode which installs a current collection line is formed including the metal or the alloy. When a current collector is installed via a metal paste on a metal or alloy, especially an electrode formed containing a metal, the metal forming the electrode reacts with the components contained in the metal paste to deform the electrode. And problems such as discoloration may occur. According to this embodiment, such a problem can be solved and the organic thin-film solar cell excellent in the external appearance can be provided.

  There is no restriction | limiting in the formation method of a lower electrode and an upper electrode, According to the material to be used, it can form by a well-known method. For example, it can be formed by a dry process such as vacuum deposition or sputtering. It can also be formed by a wet process using conductive ink or the like. As this conductive ink, 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 (electric characteristics, wetting characteristics, etc.) due to surface treatment may be improved.

The thicknesses of the upper electrode and the lower electrode are not particularly limited, but are usually 5 nm or more, preferably 10 nm or more, more preferably 20 nm or more, and further preferably 50 nm or more. On the other hand, it is usually 400 μm or less, preferably 10 μm or less, more preferably 1 μm or less, and further preferably 500 nm or less. When the thickness of the electrode is equal to or more than the lower limit, sheet resistance is suppressed and sufficient conduction is possible. On the other hand, by being below the above upper limit, flexibility can be maintained. When the electrode is a transparent electrode, it is necessary to select a film thickness that can achieve both light transmittance and sheet resistance.
The sheet resistance of the electrode is not particularly limited, but is usually 1Ω / □ or more, usually 1000Ω / □ or less, preferably 500Ω / □ or less, more preferably 100Ω / □ or less.

1.2.3.3 Organic Photoelectric Conversion Layer The photoelectric conversion layer of the organic thin film solar cell element is formed including an organic semiconductor compound, and usually contains a p-type semiconductor compound and an n-type semiconductor compound. Note that p-type and n-type indicate whether holes or electrons contribute to electrical conduction, and depend on the electronic state, doping state, and trap state of the material. Therefore, there are cases where p-type and n-type cannot always be clearly classified, and there are cases where the same substance exhibits both p-type and n-type characteristics. When the photoelectric conversion layer includes a p-type semiconductor compound and an n-type semiconductor compound, it is preferable that at least the p-type semiconductor compound is an organic semiconductor compound, and both the p-type semiconductor compound and the n-type semiconductor compound are organic semiconductor compounds. Preferably there is.

  As a specific configuration example of the photoelectric conversion 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. A layered type (hetero pn junction type) in which a layer containing an n-type semiconductor (n layer) has an interface, or a Schottky type having only one of a p-type semiconductor layer and an n-type semiconductor layer, and combinations thereof It is done. Among these, a bulk heterojunction type or a combination of a bulk heterojunction type and a stacked type (p-i-n junction type) is preferable because it exhibits high performance.

Examples of the p-type semiconductor include a p-type high molecular organic semiconductor compound or a p-type low molecular organic semiconductor compound.
The p-type organic polymer semiconductor compound is not particularly limited, and is a conjugated polymer semiconductor such as polythiophene, polyfluorene, polyphenylene vinylene, polythienylene vinylene, polyacetylene, or polyaniline; oligothiophene substituted with an alkyl group or other substituent Polymer semiconductors such as; and the like. Moreover, the semiconductor polymer which copolymerized 2 or more types of monomer units is also mentioned. As the conjugated polymer, for example, Handbook of
Conducting Polymers, 3rd Ed. (2 volumes), 2007, Materials Science and Engineering, 2001, 32, 1-40, Pure Appl. Chem. 2002, 74, 2031-3044, Handbook of THIOPHENE-BASED MATERIALS (2 volumes), 2009, International Publication No. 2011-016430, International Publication No. 2013/180243, Japanese Unexamined Patent Publication No. 2012-191194, etc. Polymers that can be synthesized by a combination of polymers described in known literatures and derivatives thereof, and monomers described therein can be used. The polymer organic semiconductor compound used as the p-type semiconductor compound may be a single compound or a mixture of a plurality of compounds.

The p-type low-molecular organic semiconductor compound is not particularly limited as long as it can function as a p-type semiconductor material. Specifically, condensed aromatic hydrocarbons such as naphthacene, pentacene or pyrene; α-sexi Oligothiophenes containing 4 or more thiophene rings such as thiophene; including at least one of thiophene ring, benzene ring, fluorene ring, naphthalene ring, anthracene ring, thiazole ring, thiadiazole ring and benzothiazole ring, and a total of 4 One or more linked ones; a phthalocyanine compound and a metal complex thereof, or a porphyrin compound such as tetrabenzoporphyrin and a metal complex thereof, or a macrocyclic compound. Preferably, they are a phthalocyanine compound and its metal complex, or a porphyrin compound and its metal complex. The molecular weight of the low-molecular organic semiconductor compound is not particularly limited both at the upper limit and the lower limit, but is usually 5000 or less, preferably 2000 or less, and is usually 100 or more, preferably 200 or more. In addition, when forming a p-type semiconductor layer by application | coating, a low molecular organic-semiconductor compound precursor can be converted into a low-molecular-weight organic semiconductor compound after application | coating. A method using a low molecular weight organic semiconductor compound precursor is more preferable in that coating film formation is easier. A low molecular organic semiconductor compound precursor is a compound that changes its chemical structure and is converted into a low molecular organic semiconductor compound by applying an external stimulus such as heating or light irradiation. A low molecular organic semiconductor compound precursor is preferable in that it has excellent film-forming properties.

  The n-type semiconductor is not particularly limited, and specifically, fullerene; fullerene compound; quinolinol derivative metal complex represented by 8-hydroxyquinoline aluminum; naphthalene tetracarboxylic acid anhydride; naphthalene tetracarboxylic acid diimide or Condensed ring tetracarboxylic acid diimides such as perylenetetracarboxylic acid diimide; perylene diimide derivatives, terpyridine metal complexes, tropolone metal complexes, flavonol metal complexes, perinone derivatives, benzimidazole derivatives, benzoxazole derivatives, thiazole derivatives, benzthiazole derivatives, benzo Thiadiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, aldazine derivatives, bisstyryl derivatives, pyrazine derivatives, phenanthroline derivatives Quinoxaline derivatives, benzoquinoline derivatives, bipyridine derivatives, borane derivatives, anthracene, pyrene, total fluoride condensed polycyclic aromatic hydrocarbons such as naphthacene or pentacene; single-walled carbon nanotubes, and the like.

  Among these, n-type semiconductor compounds include fullerene compounds, borane derivatives, thiazole derivatives, benzothiazole derivatives, benzothiadiazole derivatives, N-alkyl-substituted naphthalenetetracarboxylic acid diimides and N-alkyl-substituted perylene diimide derivatives. Preferably, fullerene compounds, N-alkyl-substituted perylene diimide derivatives and N-alkyl-substituted naphthalene tetracarboxylic acid diimides are more preferable. One of the above compounds may be used, or a mixture of a plurality of compounds may be used. An n-type semiconductor is also included as an n-type semiconductor.

  Each of the n-type semiconductor compound and the p-type semiconductor compound may be used alone, or two or more thereof may be used in any combination and ratio.

  Although there is no restriction | limiting in particular as a preparation method of an organic photoelectric converting layer, A coating method is preferable and especially a wet coating method is preferable. As the coating method, any method can be used, for example, spin coating method, reverse roll coating method, gravure coating method, kiss coating method, roll brush method, spray coating method, air knife coating method, wire barber coating method, Examples include the pipe doctor method, the impregnation / coating method, and the curtain coating method. In the case where the photoelectric conversion layer is formed by a roll-to-roll method, it is preferable to apply a wet coating method because the apparatus is simple, the cost is low, and the photoelectric conversion layer can be formed quickly in large quantities. When performing the wet coating method, it is preferable to select a solvent that does not dissolve the coating layer.

  The film thickness of the organic photoelectric conversion layer is not particularly limited, but is usually 50 nm or more, preferably 100 nm or more in order to increase the photocurrent, while it is usually 1000 nm or less in order to suppress series resistance. Yes, it is 500 nm or less.

1.2.3.4 Buffer Layer The organic thin-film solar cell element in the present embodiment may include a buffer layer between the lower electrode and the photoelectric conversion layer and / or the upper electrode and the photoelectric conversion layer. The buffer layer refers to an electron extraction layer and / or a hole extraction layer. The buffer layer is not essential in the organic thin film solar cell element according to the present invention, and may include only one of an electron extraction layer and a hole extraction layer. The electron extraction layer is preferably present between the cathode and the organic photoelectric conversion layer,
The hole extraction layer is preferably present between the anode and the organic photoelectric conversion layer.

Specifically, when the upper electrode is an anode, the lower electrode is a cathode, and the organic thin-film solar cell element has both an electron extraction layer and a hole extraction layer as buffer layers, the organic thin-film solar cell element is It is preferable to have a lower electrode, an electron extraction layer, a photoelectric conversion layer, a hole extraction layer, and an upper electrode in this order. When the organic thin film solar cell element has an electron extraction layer and does not have a hole extraction layer, the organic thin film solar cell element has a lower electrode, an electron extraction layer, a photoelectric conversion layer, and an upper electrode in this order. preferable. Similarly, when the organic thin film solar cell element has a hole extraction layer and does not have an electron extraction layer, the organic thin film solar cell element has a lower electrode, a photoelectric conversion layer, a hole extraction layer, and an upper electrode. It is preferable to have this order.
Further, at least one of the electron extraction layer and the hole extraction layer may be composed of a plurality of different layers.

[Electronic extraction layer]
The material of the electron extraction layer is not particularly limited as long as it is a material that improves the efficiency of extracting electrons from the photoelectric conversion layer to the cathode, and examples thereof include inorganic compounds and organic compounds.

  Examples of the material of the inorganic compound include salts of alkali metals such as Li, Na, K or Cs; n-type semiconductor oxides such as titanium oxide (TiOx) and zinc oxide (ZnO). Among them, the alkali metal salt is preferably a fluoride salt such as LiF, NaF, KF or CsF, and the n-type semiconductor oxide is preferably zinc oxide (ZnO). Although the operation mechanism of such materials is unknown, it is possible to reduce the work function of the cathode when combined with a cathode made of Al or the like and increase the voltage applied to the inside of the organic thin film solar cell element. It is done.

  Examples of organic compound materials include, for example, phosphine compounds having a double bond between a phosphorus atom and a group 16 element such as triarylphosphine oxide compounds; bathocuproin (BCP) or bathophenanthrene (Bphen), A phenanthrene compound which may have a substituent and may be substituted at the 1-position and the 10-position with a heteroatom; a boron compound such as triarylboron; and (8-hydroxyquinolinato) aluminum (Alq3) Organometallic oxide; Compound having 1 or 2 ring structure which may have a substituent such as oxadiazole compound or benzimidazole compound; Naphthalenetetracarboxylic anhydride (NTCDA) or perylenetetracarboxylic acid Of dicarboxylic anhydrides, such as anhydrides (PTCDA) Aromatic compounds having Unachijimigo dicarboxylic acid structure.

  The thickness of the electron extraction layer is not particularly limited, but is usually 0.01 nm or more, preferably 0.1 nm or more, more preferably 0.5 nm or more. On the other hand, it is usually 400 nm or less, preferably 200 nm or less. When the thickness of the electron extraction layer is equal to or more than the above lower limit, the function as a buffer material is achieved. When the thickness of the electron extraction layer is not more than the above upper limit, electrons can be easily extracted and the photoelectric conversion efficiency can be improved.

  There is no restriction | limiting in the formation method of an electronic taking-out layer. For example, when a material having sublimation property is used, it can be formed by a vacuum deposition method or the like. Specifically, for example, when an alkali metal salt is used as a material for the electron extraction layer, the electron extraction layer can be formed by using a vacuum film formation method such as vacuum deposition or sputtering. Especially, it is desirable to form an electron taking-out layer by vacuum vapor deposition by resistance heating. By using vacuum deposition, damage to other layers such as a photoelectric conversion layer can be reduced.

  Further, for example, when using a material soluble in a solvent, the spin coating method, reverse roll coating method, gravure coating method, kiss coating method, roll brush method, spray coating method are used in the same manner as the method for producing the photoelectric conversion layer described above. It can be formed by a wet coating method such as an air knife coating method, a wire barber coating method, a pipe doctor method, an impregnation / coating method, a curtain coating method, or the like.

  On the other hand, for metal oxides of n-type semiconductors, for example, when zinc oxide ZnO is used as the material for the electron extraction layer, a vacuum film formation method such as sputtering can be used. It is desirable to form the extraction layer. For example, Sol-Gel Science, C.I. J. et al. Brinker, G.M. W. According to the sol-gel method described by Scherer, Academic Press (1990), an electron extraction layer composed of zinc oxide can be formed. In this case, the thickness is usually 0.1 nm or more, preferably 2 nm or more, more preferably 5 nm or more, and usually 1 μm or less, preferably 100 nm or less, more preferably 50 nm or less. If the electron extraction layer is too thin, the effect of improving the electron extraction efficiency is not sufficient, and if it is too thick, the electron extraction layer tends to deteriorate the characteristics of the device by acting as a series resistance component.

  In the case where the electron extraction layer is formed by a roll-to-roll method, it is preferable to apply a wet coating method because the apparatus is simple, the cost is low, and the electron extraction layer can be formed quickly in large quantities. When performing the wet coating method, it is preferable to select a solvent that does not dissolve the coating layer.

[Hole extraction layer]
The material for the hole extraction layer is not particularly limited as long as it is a material that can improve the efficiency of extracting holes from the photoelectric conversion layer to the anode. Specifically, a conductive polymer in which polythiophene, polypyrrole, polyacetylene, triphenylenediamine, polyaniline or the like is doped with sulfonic acid and / or iodine, etc .; a conductive organic material such as a polythiophene derivative having a sulfonyl group as a substituent, arylamine or the like Compound: Metal oxide such as copper oxide, nickel oxide, manganese oxide, molybdenum oxide, vanadium oxide or tungsten oxide; Nafion, p-type semiconductor described later, and the like. Among them, a conductive polymer doped with sulfonic acid is preferable, and (3,4-ethylenedioxythiophene) poly (styrenesulfonic acid) (PEDOT: PSS) in which a polythiophene derivative is doped with polystyrene sulfonic acid is more preferable. It is. A thin film of metal such as gold, indium, silver or palladium can also be used. A thin film of metal or the like may be formed alone or in combination with the above organic material.

  The thickness of the hole extraction layer is not particularly limited, but is usually 0.2 nm or more. On the other hand, it is usually 400 nm or less, preferably 200 nm or less. When the thickness of the hole extraction layer is 0.2 nm or more, it functions as a buffer material. When the thickness of the hole extraction layer is 400 nm or less, holes can be easily extracted and the photoelectric conversion efficiency can be improved.

  There is no restriction | limiting in the formation method of a positive hole taking-out layer. For example, when a material having sublimation property is used, it can be formed by a vacuum deposition method or the like. For example, when using a material soluble in a solvent, a spin coating method, a reverse roll coating method, a gravure coating method, a kiss coating method, a roll brush method, a spray coating method, an air knife coating method, a wire barber coating method, a pipe doctor It can be formed by a wet coating method such as a method, an impregnation / coating method, or a curtain coating method. The hole extraction layer is preferably formed by coating. When a semiconductor material is used for the hole extraction layer, the precursor may be converted into a semiconductor compound after the layer is formed using the precursor, similarly to the low-molecular organic semiconductor compound of the organic photoelectric conversion layer described later.

Especially, when using PEDOT: PSS as a material of a hole taking-out layer, it is preferable to form a hole taking-out layer by the method of apply | coating a dispersion liquid. Examples of the dispersion of PEDOT: PSS include CLEVIOSTM series manufactured by Heraeus, ORGACONTM series manufactured by Agfa, and the like.
When the hole extraction layer is formed by a roll-to-roll method, it is preferable to apply a wet coating method because the apparatus is simple, the cost is low, and the hole extraction layer can be formed quickly in large quantities. When performing the wet coating method, it is preferable to select a solvent that does not dissolve the coating layer.

1.2.4 Adhesive Layer The organic thin film solar cell module according to this embodiment preferably has an adhesive layer for installation on a window glass. The adhesive layer is located on the outermost layer of the organic thin film solar cell module, and is a layer for adhering the organic thin film solar cell module to a construction object such as glass.
As the adhesive layer, a known transparent adhesive can be used. For example, acrylic adhesives, polyester adhesives, rubber adhesives, silicone adhesives, polyurethane adhesives and the like can be mentioned. Among these, an acrylic pressure-sensitive adhesive material is preferable from the viewpoint of weather resistance and transparency.

  The adhesive layer can be provided by a known method on the outermost layer of the organic thin film solar cell module on the substrate side (light receiving surface) or photoelectric conversion layer side (non-light receiving surface) of the organic thin film solar cell element. From the viewpoint of power generation efficiency of the solar cell element, it is preferable to provide it on the outermost layer on the substrate side (light receiving surface) of the organic thin film solar cell element.

The adhesive layer can be provided by a known method on the outermost layer on the light receiving surface or non-light receiving surface side of the organic thin film solar cell module. For example, an adhesive material can be provided on a release paper, dry laminated on the outermost layer of the solar cell, and then released by peeling the release paper.
It is preferable that the adhesive layer has sufficient adhesive force and adhesive force so that the glass does not scatter when the window glass is broken. Specifically, a method having a peeling force of about 4.0 N / 25 mm or more can be used by the method shown in JIS A 5759.

  The thickness of the adhesive layer is not particularly limited, but is usually 20 μm or more, preferably 30 μm or more, more preferably 50 μm or more, and usually 500 μm, preferably 300 μm or less, more preferably 200 μm or less. Sufficient adhesiveness is ensured by being more than the said minimum, and the squeegee property at the time of installing in construction objects, such as a window glass, improves by being below the said upper limit.

  In addition, an organic thin film solar cell module can be manufactured by a well-known method using said structural member. For example, it can be manufactured by laminating a gas barrier layer, a sealing layer, a thin film solar cell element and the like, and vacuum-sucking the laminated body and thermocompression bonding. Moreover, you may manufacture by a batch system and can also manufacture by a roll-to-roll system.

1.2.5 Other Layers The organic thin film solar cell module according to the present invention may have constituent members other than those described above. For example, you may have a protective layer, an ultraviolet cut layer, a getter layer, etc. between the surface of a gas barrier layer, between a gas barrier layer and a sealing layer, and between a gas barrier layer and an adhesion layer. These layers can also be used as a gas barrier layer. FIG. 3 shows a configuration example of an organic thin film solar cell module in which the getter layer is provided between the gas barrier layer and the sealing layer. FIG. 3 shows a configuration in which a collecting wire 11 is installed on the upper electrode.

(Getter layer)
The getter layer is a layer that absorbs moisture and / or oxygen. Some components of the thin-film solar cell element are deteriorated by moisture as described above, and some are deteriorated by oxygen. Therefore, by covering the thin film solar cell element with the getter layer, the thin film solar cell element and the like are protected from moisture and / or oxygen, and the power generation performance is maintained high.

  Here, unlike the gas barrier layer as described above, the moisture getter layer does not prevent moisture permeation but absorbs moisture. When a thin film solar cell element is covered with a gas barrier layer or the like by using a layer that absorbs moisture, the getter layer captures the moisture that slightly enters the space formed between the gas barrier layers, and the thin film solar cell element due to moisture The influence on can be eliminated.

The degree of water absorption capacity of the getter layer is usually 0.1 mg / cm ² or more, preferably 0.5 mg / cm ² or more, more preferably 1 mg / cm ² or more. The higher this value, the higher the water absorption capacity, and the deterioration of the thin film solar cell element 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 thin film solar cell element is covered with a gas barrier layer or the like because the getter layer absorbs oxygen, the getter layer captures oxygen that slightly enters the space formed by the gas barrier layer and the thin film solar cell by oxygen The influence on the battery element can be eliminated.

  Further, the getter layer preferably transmits visible light from the viewpoint of not hindering light absorption of the thin film solar cell element. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 60% or more, preferably 70% or more, more preferably 75% or more, still more preferably 80% or more, and particularly preferably 85% or more. Preferably it is 90% or more, Especially preferably, it is 95% or more, Especially preferably, it is 97% or more. This is to convert more sunlight into electrical energy.

  Furthermore, since the organic thin film solar cell module is often heated by receiving light, it is preferable that the getter layer also has heat resistance. From this viewpoint, the melting point of the constituent material of the getter layer is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and usually 350 ° C. or lower, preferably 320 ° C. or lower, more preferably 300 ° C. It is below ℃. By increasing the melting point, it is possible to reduce the possibility that the getter layer will melt and deteriorate when the organic thin film solar cell module is used.

  The material constituting the getter layer is arbitrary as long as it can absorb moisture and / or oxygen. Examples of the material include alkali metal, alkaline earth metal or alkaline earth metal oxides; alkali metal or alkaline earth metal hydroxides; silica gel, zeolitic compounds, 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. In addition, Zr-Al-BaO and aluminum metal complexes are also included. 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, Zn, and inorganic salts such as sulfates, chlorides, and nitrates of these metals are also included.
Note that the getter layer may be formed of one kind of material or may be formed of two or more kinds of materials. In addition, the getter layer may be formed as a single layer, but may be a laminate including two or more layers.

The thickness of the getter layer is not particularly defined, but is usually 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more, and usually 200 μm or less, preferably 180 μm.
Hereinafter, it is more preferably 150 μm or less. Increasing the thickness tends to increase mechanical strength, and decreasing the thickness tends to increase flexibility.

The storage elastic modulus of the getter layer at 25 ° C. and a frequency of 10 Hz is not particularly limited, but in order to prevent the organic thin film solar cell element from being damaged due to the deformation of the getter layer when subjected to external stress, 1 is preferably .0 × 10 ⁶ Pa or more, more preferably 5.0 × 10 ⁶ Pa or more, and particularly preferably 1.0 × 10 ⁷ Pa or higher. On the other hand, when the solar cell module is bent, in order to provide a function as a relaxation layer against bending stress applied to the first sealing layer and prevent delamination in the organic thin film solar cell element, the getter layer has a temperature of 25 ° C. The storage elastic modulus at 10 Hz is preferably 5.0 × 10 ⁸ Pa or less, more preferably 3.0 × 10 ⁸ Pa or less, and particularly preferably 1.0 × 10 ⁸ Pa or less. .

  The formation position of the getter layer is not limited as long as it is in the space formed between the gas barrier layers, but both surfaces of the thin film solar cell element, specifically, the light receiving surface side surface (the lower surface in FIG. 3). It is preferable to cover the surface opposite to the light receiving surface (the upper surface in FIG. 3). In organic thin-film solar cell modules, the surface on the light-receiving surface side and the surface opposite to the light-receiving surface side are often formed in a larger area than the other surfaces, so moisture and oxygen enter through these surfaces. Because there is a tendency to. From this viewpoint, the getter layer is preferably provided between the gas barrier layer and the thin film solar cell element.

  The getter layer 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, a solution of the water-absorbing agent or the desiccant The method etc. which apply | coat this by a spin coat method, the inkjet method, or a dispenser method etc. can be used. Further, 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, or the like can be used. Among these, a film of polyethylene resin, fluorine resin, cyclic polyolefin resin or polycarbonate resin is preferable. In addition, the said resin may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

(Protective layer)
As described above, the organic thin-film solar cell module according to the present invention may have a protective layer (surface protective layer and / or back surface protective layer).
A protective layer is a layer which protects an organic thin film solar cell module from the installation environment of an organic thin film solar cell module, such as a temperature change, humidity change, light, and a wind and rain. By covering the surface of the organic thin film solar cell module with the protective layer, the material of the organic thin film solar cell module, in particular, the organic thin film solar cell element is protected, and there is an advantage that high power generation capability can be obtained without deterioration. .

Since the protective layer is located on the outermost layer of the organic thin film solar cell module, it is suitable as a surface covering material for the organic thin film solar cell module such as weather resistance, heat resistance, transparency, water repellency, contamination resistance, mechanical strength, etc. It is preferable to have performance and to maintain it for a long period of time in outdoor exposure.
Moreover, when a protective layer is used for the light-receiving surface side of an organic thin-film solar cell element, it is preferable to transmit visible light from the viewpoint of not preventing light absorption. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 75% or more, preferably 80% or more, more preferably 85% or more, further preferably 90% or more, and particularly preferably 95% or more. Particularly preferably, it is 97% or more. This is to convert more sunlight into electrical energy.
Further, the protective layer preferably has a low haze from the viewpoint of design properties such as a sense of unity with the construction object and appearance. For example, the haze value when using a D65 light source defined by JIS K 7136 is usually 10 or less, preferably 5 or less, more preferably 2 or less, and even more preferably 1 or less.

On the other hand, the protective layer on the side opposite to the light-receiving surface of the thin-film solar cell element does not necessarily need to transmit visible light and may be opaque, but when pasted on a transparent construction object such as a window glass, the thin-film solar cell It is preferable to have the same visible light transmittance and haze as the light receiving surface side of the element.
Furthermore, since the thin film solar cell element is often heated by receiving light, the protective layer preferably has resistance to heat. From this viewpoint, the melting point of the constituent material of the protective layer is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and usually 350 ° C. or lower, preferably 320 ° C. or lower, more preferably 300 It is below ℃. By increasing the melting point, it is possible to reduce the possibility that the protective layer melts and deteriorates when the thin film solar cell element is used.

  The material which comprises a protective layer is arbitrary as long as it can protect an organic thin film solar cell module. 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 Examples thereof include polyester resins such as naphthalate, phenol resins, polyacrylic resins, polyamide resins such as various nylons, polyimide resins, polyamide-imide resins, polyurethane resins, cellulose resins, silicone resins, and polycarbonate resins.

  Among them, fluorine resin is preferable, and specific examples thereof include polytetrafluoroethylene (PTFE), 4-fluoroethylene-perchloroalkoxy copolymer (PFA), 4-fluoroethylene-6-fluoride. Propylene copolymer (FEP), 2-ethylene-4-fluoroethylene copolymer (ETFE), poly-3-fluoroethylene chloride (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), etc. Can be mentioned.

  Note that the protective layer may be formed of one type of material or may be formed of two or more types of materials. The protective layer may be formed of a single layer film, but may be a laminated film including two or more films.

  The thickness of the protective layer is not particularly defined, but is usually 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, further preferably 30 μm or more, particularly preferably 50 μm or more, and usually 200 μm or less, preferably 180 μm or less. More preferably, it is 150 μm or less. It exists in the tendency for the mechanical strength of an organic thin-film solar cell module to increase by being more than the said minimum, and it exists in the tendency for a softness | flexibility to increase by being below the said upper limit. For this reason, it is desirable to set it as the said range as a range which has both advantages.

The protective layer may be subjected to surface treatment such as corona treatment or plasma treatment in order to improve the adhesion with other films.
The protective layer is preferably provided on the outer side of the organic thin film solar cell module as much as possible. This is because more device components can be protected.

In addition, the protective layer has ultraviolet blocking, heat blocking, antifouling, hydrophilic, hydrophobic, antifogging, abrasion resistance, conductivity, antireflection, antiglare, light diffusion, light scattering, wavelength conversion, gas barrier properties Such functions may be given. In particular, in the case of an organic thin film solar cell, since it may be deteriorated by the ultraviolet rays of sunlight, it is preferable to have an ultraviolet blocking function.
As a method for imparting such a function, a layer having a function may be laminated on the protective layer by coating film formation or the like, or a material that exhibits a function may be dissolved and dispersed to be contained in the protective layer. May be.

  In addition, the protective layer is hard-coated to prevent scratches when handling organic thin-film solar cell modules, to prevent scratches due to squeegees when applying water to construction objects, and to improve the smoothness of the protective layer. A layer may be provided.

  As the hard coat layer, conventionally known ones can be used, such as an ultraviolet curable resin; an electron beam curable resin; an alkoxysilane hydrolytic condensation resin; a melamine resin; a (meth) acrylate alcohol-modified polyfunctional compound; Examples include layers made of acrylic resins such as methylolpropane (meth) acrylate, tripropylene glycol diacrylate, pentaerythritol triacrylate, 1,6 hexanediol (meth) acrylate, but are not limited thereto. The hard coat layer preferably has a pencil hardness of 2H or higher, more preferably 3H or higher. Moreover, it is preferable that the film thickness is 1-10 micrometers. If it is less than 1 μm, the effect of scratch resistance may not be sufficient, and if it is 10 μm or more, the protective layer may curl due to curing shrinkage of the hard coat layer.

(UV cut layer)
As described above, the organic thin-film solar cell module according to the present invention may have an ultraviolet cut layer.
The ultraviolet cut layer is a layer that prevents transmission of ultraviolet rays.
Some components of the organic thin film solar cell module are deteriorated by ultraviolet rays. Some gas barrier layers are deteriorated by ultraviolet rays depending on the type. Therefore, an ultraviolet cut layer is provided on the light receiving portion of the organic thin film solar cell module, and the thin film solar cell element and, if necessary, the gas barrier layer are protected from ultraviolet rays by covering the light receiving surface of the thin film solar cell element with the ultraviolet cut layer. The power generation performance can be kept high.

The degree of the ability to suppress the transmission of ultraviolet rays required for the ultraviolet cut layer is such that the transmittance of ultraviolet rays (for example, wavelength of 300 nm) is preferably 50% or less, more preferably 30% or less, and particularly preferably 10 % Or less.
In addition, the ultraviolet cut layer is preferably one that transmits visible light from the viewpoint of not hindering light absorption of the thin film solar cell element. 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.

  Further, since the organic thin film solar cell module is often heated by receiving light, it is preferable that the ultraviolet cut layer also has heat resistance. From this viewpoint, the melting point of the constituent material of the ultraviolet cut layer is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher. Moreover, it is 350 degrees C or less normally, Preferably it is 320 degrees C or less, More preferably, it is 300 degrees C or less. If the melting point is too low, there is a possibility that the ultraviolet cut layer melts when the organic thin film solar cell module is used.

In addition, the ultraviolet cut layer is preferably highly flexible, has good adhesion with an adjacent layer, and can cut water vapor and oxygen.
The material constituting the ultraviolet cut layer is arbitrary as long as it can weaken the intensity of ultraviolet rays. Examples of the material include a layer formed by blending an ultraviolet absorber with an epoxy resin, an acrylic resin, a urethane resin, or an ester resin. Moreover, you may use as a laminated body which formed the layer (henceforth an "ultraviolet absorption layer" suitably) of what disperse | distributed or melt | dissolved the ultraviolet absorber in resin on the base film.

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 preferable. 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 an example of a specific product of the ultraviolet cut layer, cut ace (MKV Plastic Co., Ltd.) and the like can be given.

In addition, the ultraviolet cut layer may be formed of one type of material or may be formed of two or more types of materials. Further, the ultraviolet cut layer may be formed of a single layer film, but may be a laminate including two or more layers.
The thickness of the ultraviolet cut layer is not particularly defined, but is usually 5 μm or more, preferably 10 μm or more, more preferably 15 μm or more. Moreover, it is 200 micrometers or less normally, Preferably it is 180 micrometers or less, More preferably, it is 150 micrometers or less. Increasing the thickness tends to increase the absorption of ultraviolet rays, and decreasing the thickness tends to increase the transmittance of visible light.

  What is necessary is just to provide an ultraviolet-ray cut layer in the position which covers at least one part of the light-receiving surface of a thin film solar cell element. It is preferable to provide it at a position covering the entire light receiving surface of the thin film solar cell element. However, the ultraviolet cut layer may be provided at a position other than the position covering the light receiving surface of the thin film solar cell element.

1.2.6 Current Collector A general thin film solar cell module usually has a current collector for extracting electricity from the thin film solar cell element. As a material for the current collector, metals, alloys, and the like are often used, and among them, it is preferable to use copper, aluminum, silver, gold, nickel, or the like having a low resistivity. Among these, copper and aluminum are particularly preferable because they are inexpensive. In order to prevent rust, the current collector may be plated with tin, silver or the like, the surface may be coated with resin, or a film may be laminated. As the shape of the current collecting wire, there are a rectangular wire, foil, flat plate, and wire shape, but for reasons such as securing a bonding area, it is preferable to use a flat wire, foil, or flat plate shape.
Here, “foil” means a material having a thickness of less than 100 μm, and “plate” means a material having a thickness of 100 μm or more. Further, the “flat wire” refers to a wire whose cross section is rolled to make the cross section into a quadrangle.

  The current collector is not particularly limited as long as it has conductivity, but preferably has a lower electrical resistance value than the upper electrode and lower electrode to be connected, and in particular, by increasing the thickness of the upper electrode and lower electrode. It is preferable to reduce the electric resistance value. The thickness of the current collector is preferably 5 μm or more, more preferably 10 μm or more. Moreover, it is preferable that it is 2 mm or less, More preferably, it is 1 mm or less, More preferably, it is 300 micrometers or less, Most preferably, it is 200 micrometers or less. If the thickness is smaller than the above range, the resistance value of the current collector increases, and the generated power may not be efficiently taken out to the outside. If the thickness is larger than the above range, the weight of the thin-film solar cell module increases and the flexibility decreases, irregularities are easily generated on the module surface, and the production cost increases. There is a fear.

  The width of the current collector is preferably 0.5 mm or more, more preferably 1 mm or more, and particularly preferably 2 mm or more. Moreover, it is preferable that the width | variety of a current collection line is 50 mm or less, More preferably, it is 20 mm or less, Most preferably, it is 10 mm or less. If the width of the current collection line is narrower than the above range, the electrical resistance value of the current collection line will increase, and the generated power may not be taken out efficiently. In addition, the mechanical strength of the current collector decreases, which may cause breakage and the like. Moreover, when the width | variety of a current collection line is wider than the said range, the aperture ratio in the whole module will reduce, and there exists a possibility of leading to the fall of the power generation amount of a module.

  In addition, the shape of the current collector line can be embossed. The embossed shape means a shape formed by embossing some uneven shape. By forming the current collector in an embossed shape, even if an adhesive layer is used, a portion of the embossed unevenness can be in direct contact with or very close to the electrode, so that conductivity is increased.

  The embossing depth is usually 5 to 100 μm, and preferably 10 to 50 μm. The emboss depth means the height of the convex portion formed by embossing, and is specifically a value obtained by subtracting the thickness of the current collector from the thickness including the convex portion. Such an embossing depth is preferable because the embossed convex portion can directly contact the electrode.

  The current collector is connected to the electrode through the conductive adhesive layer. As a conductive adhesive component to be installed on an electrode of a solar cell, a thermosetting composition containing conductive particles, a thermoplastic plastic containing conductive particles, solder, a metal paste, and the like are known, and known conductive adhesion Layers can be used.

2. Organic thin film solar cell module construction method The organic thin film solar cell module construction method can be arbitrarily selected according to the construction object, but the organic thin film solar cell module of this embodiment is suitable as a solar cell integrated wind film. In this case, it can be applied in the same manner as a general window film.
A general wind film is attached to glass by a method called water sticking. This method of sticking with water is to stick the film on the glass surface by spraying water containing a small amount of neutral detergent on the adhesive surface and glass surface of the film with a sprayer, and then squeegeeing the film surface sequentially. Rub evenly to adhere. As a result, water and air bubbles between the film and the glass are expelled from the end of the film, and a good bonding surface free from wrinkles and air bubbles can be obtained.

3. Application The organic thin film solar cell module of the present invention can be used by being attached to an adherend such as glass such as a partition, glass such as a window, a door, a wall surface, or a ceiling, such as a building or a vehicle. At this time, power is generated using sunlight, indoor lighting, indoor sunlight scattered light, etc., and the electric power taken out from the current collector is charged and used using a known current-voltage conversion circuit, storage battery, etc. be able to. In particular, the organic thin film solar cell module of the present invention is excellent in durability and design as a solar cell integrated wind film.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to a following example.
<Evaluation method>
In this example, the organic thin film solar cell module was evaluated by the following method.
[Thickness measurement method]
Using a contact thickness meter (KG601A, manufactured by Anritsu Co., Ltd.), the thickness x (μm) of the organic thin film solar cell module in the center of the current collecting wire width direction in the current collecting wire installation region and the outer peripheral edge of the organic thin film solar cell element The thickness y (μm) of a 5 mm organic thin film solar cell module is measured, and (xy
) (Μm) value was calculated.
[Evaluation method of bubbles after squeegee]
From the observation results of the organic thin-film solar cell module, “◯”, “Δ”, and “x” were determined according to the following criteria.
After producing the organic thin film solar cell module, after one day or more, the presence or absence of water and bubbles between the organic thin film solar cell module and the glass was observed from a position 1 m away and a position 0.1 m away.
○: Water and bubbles are not visible from a position 0.1 m away Δ: Water and bubbles are not visible from a position 1 m away ×: Water and bubbles are visible from a position 1 m away

<Example 1>
An organic thin-film solar cell module having the configuration shown in FIG. 2 was prepared by the following procedure.
As a pre-preparation before stacking, on the upper electrode of the thin-film solar battery cell at both ends of the organic thin-film solar battery element, a collector wire with a conductive thermosetting resin composition (DT101C4, manufactured by Dexerials, Inc.) Epoxy conductive curable resin containing, curing temperature 120 ° C.) 15 μm + copper foil thickness 35 μm, width 4 mm).
A vertical film in which a sealing material (manufactured by ThreeBond, 16 × 134) having a thickness of 40 μm is laminated as a second sealing layer on a barrier film (Mitsubishi Resin, VIEW-BARRIER, VDK3DA) which is a material of the second gas barrier layer. Thickness that is a material for the first gas barrier layer, a total thickness of 120 μm, a length of 150 mm, a width of 100 mm, and an organic thin film solar cell element including an organic thin film solar cell element substrate on which a 300 mm, 200 mm wide film and then a pair of current collectors are installed A 300 mm long and 200 mm wide film in which a 40 μm thick sealing material (manufactured by ThreeBond, 16 × 134) is laminated as a first sealing layer on a 60 μm thick barrier film (Mitsubishi Resin, VIEW-BARRIER, VDK3DA) A laminated body placed so that the stopper is in contact with the organic thin-film solar cell element is attached to a vacuum laminator (NP It installed in C company make, NLM-270 * 400).

  After holding the inside of the vacuum laminator for 14 minutes under reduced pressure, the laminate was held at 140 ° C. for 3 minutes while being brought into a pressure-bonded state at atmospheric pressure. The laminated body taken out from the vacuum laminator was heated for 60 minutes in a 120 ° C. hot air oven (manufactured by Yugrop Co., Ltd.), and after cooling, a commercially available acrylic pressure-sensitive adhesive having a thickness of 120 μm was applied to the surface of the second gas barrier layer using a roll laminator (MCK , MRS630A) to produce an organic thin film solar cell module.

  After spraying a 1% surfactant aqueous solution on the acrylic adhesive, the organic thin film solar cell module was attached to a 3.2 mm thick float glass sprayed with the same 1% surfactant aqueous solution, and acrylic with a nylon squeegee. A 1% aqueous surfactant solution and air bubbles between the adhesive and the float glass were removed, and an organic thin film solar cell module was placed on the float glass.

<Example 2>
An organic thin film solar cell module was produced in the same manner as in Example 1 except that the thickness of each of the first sealing layer and the second sealing layer was 50 μm, and the organic thin film solar cell module was placed on the float glass. .
<Example 3>
An organic thin film solar cell module was produced in the same manner as in Example 1 except that the thickness of each of the first sealing layer and the second sealing layer was 60 μm, and the organic thin film solar cell module was placed on the float glass. .
<Example 4>
An organic thin film solar cell module was produced in the same manner as in Example 1 except that the thickness of the first sealing layer was 30 μm and the thickness of the second sealing layer was 60 μm. Installed on float glass.
<Example 5>
An organic thin film solar cell module was manufactured in the same manner as in Example 1 except that the thickness of the first sealing layer was 60 μm and the thickness of the second sealing layer was 30 μm. Installed on float glass.
<Example 6>
A thin-film solar cell module was produced in the same manner as in Example 1 except that the first and second sealing layers were olefin resins having a thickness of 30 μm (manufactured by Kurabo Industries, Crabetter, M-2).
<Example 7>
A thin-film solar cell module was manufactured in the same manner as in Example 1 except that a butyl rubber adhesive (manufactured by Sumitomo 3M) having a thickness of 30 μm was used as the first and second sealing layers.

<Comparative Example 1>
An organic thin film solar cell module was manufactured in the same manner as in Example 1 except that the thickness of each of the first sealing layer and the second sealing layer was 30 μm, and the temperature at the time of pressure bonding by the vacuum laminator was 120 ° C. The organic thin film solar cell module was installed on the float glass.
<Comparative example 2>
An organic thin film solar cell module is manufactured in the same manner as in Example 1 except that the thickness of each of the first sealing layer and the second sealing layer is 30 μm, and the organic thin film solar cell module is installed on the float glass. did.
<Comparative Example 3>
A thin film solar cell module was manufactured in the same manner as in Example 1 except that 60 μm thick butyl rubber adhesive (manufactured by Sumitomo 3M) was used as the first and second sealing layers.
In Table 1, the evaluation result of the organic thin film solar cell module of Examples 1-7 and Comparative Examples 1-3 is shown.

  From Table 1, it is clear that the thin-film solar cell module according to the present embodiment is a thin-film solar cell module having a good design after squeegeeing during water application.

DESCRIPTION OF SYMBOLS 1 2nd gas barrier layer 2 1st gas barrier layer 3 2nd sealing layer 4 1st sealing layer 5 Element substrate 6 Lower electrode 7 Organic photoelectric conversion layer 8 Upper electrode 9 Organic thin film solar cell element 10 Adhesive layer 11 Current collector 12 Getter Layer 13 Current collector installation area

Claims (2)

The first gas barrier layer, the first sealing layer, the organic thin film solar cell element, the second sealing layer, and the second gas barrier layer are sequentially laminated, and the organic thin film solar is interposed between the first sealing layer and the organic thin film solar cell element. An organic thin film solar cell module having a collector wire electrically connected to a battery element,
The thickness x (μm) of the organic thin film solar cell module at the center in the width direction of the current collection line in the current collection line installation region, and the thickness y (μm) of the thin film solar cell module 5 mm outside from the outer peripheral edge of the organic thin film solar cell element Satisfies the following formula (I): an organic thin film solar cell module.
(Xy) ≦ 90 (I)   The organic thin-film solar cell module of Claim 1 which has a 1st gas barrier layer, a 1st sealing layer, an organic thin-film solar cell element, a 2nd sealing layer, a 2nd gas barrier layer, and an adhesion layer one by one.

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