JP2001044474A - Solar cell module - Google Patents

Abstract

(57) [Summary] [Problem] To provide a solar cell module in which the light receiving surface side of the solar cell module can be made to have a black color tone so as to be particularly suitable for a black clock face or the like, and the function is not deteriorated. I do. SOLUTION: In a solar cell module having silicon and having a photoelectric conversion unit for converting incident light incident from a light receiving surface into electricity, a portion located on the light receiving surface side of silicon of the photoelectric conversion unit is provided. A solar cell module provided with a black coloring layer and a blue coloring layer at a portion between the black coloring layer and the silicon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable solar cell module typified by an electronic device mounted with a solar cell, and more particularly to a solar cell module as a photovoltaic device. The present invention relates to a solar cell module in a case where a jet-black and uniform black color tone is required from a design point of view, such as a black dial of a watch or the like.

[0002]

2. Description of the Related Art Solar cells are used in various electronic devices as a power source replacing dry cells and the like. In particular, electronic devices with low power consumption, such as electronic desk calculators, clocks, and portable electronic devices (cameras, mobile phones, consumer radar detectors), etc., can be sufficiently driven by the electromotive force of the solar cell, and the battery needs to be replaced. Is attracting attention because it can be operated semi-permanently and is environmentally clean.

However, when such a solar cell is mounted on an electronic device, it is necessary to consider the design. In particular, recent electronic devices are unlikely to be superior or inferior in performance, and consumers' preferences for products often depend on the quality of design. Due to the structure of the solar cell, the mechanism of the light receiving surface is visually recognized from the outside. For this reason, the lightness difference and color difference between the photoelectric conversion unit having the photoelectric conversion function of the light receiving surface and other parts, such as electrodes and partition walls, have a large effect on the design. In general, when these structures are recognized from the outside, they often have a bad influence on design.

Japanese Patent Application Laid-Open No. 60-148174 discloses a light in a wavelength range that selectively reflects light of a specific wavelength of visible light, transmits the remaining light, and contributes to power generation of the solar cell on the front surface of the solar cell. A selective reflection layer (a multilayer interference filter such as a dichroic mirror) transmitting at least a part of
Further, a solar cell provided with a light diffusion layer on its front surface is described. With such a configuration, the dark-colored solar cell is the lowermost layer, a “selective reflection layer” is provided on the light-receiving surface side, and the color tone is changed to a desired color. To make the color of the reflected light brighter,
There is a description that the dark color of the solar cell is reduced so that the color tone can be controlled to some extent, the degree of freedom in design design including the color tone of the mounting system can be given, and a sense of incongruity in product design due to the mounting of the solar cell can be reduced.

Japanese Patent Publication No. 5-38464 (corresponding to Japanese Patent Application Laid-Open No. 60-148172) discloses a color filter which is provided on the front surface of a solar cell and transmits light in a wavelength range that contributes to power generation of the solar cell. And a solar cell provided between the solar cell and the color filter, having a color diffusion layer including a scattering layer that transmits part of the light transmitted by the color filter and scatters the remainder in all directions. Has been described. With such a configuration, a part of the light transmitted by the color filter can be transmitted by the scattering layer, and the rest can be scattered in all directions by the scattering layer. There is a statement that the solar cell can be seen from any position and the color of the solar cell looks like a color filter, expanding its use as a colorful exterior product.

In Japanese Utility Model Publication No. Hei 7-29646,
On the front surface of the solar cell, light of a specific wavelength of visible light including light in a wavelength range that contributes to the power generation of the solar cell is scattered in all directions, and a part of the scattered light reaches an observer and the scattering is performed. A solar cell provided with a wavelength-selective scattering layer that transmits another part of light and light other than the specific wavelength is described. And with such a configuration, the wavelength selective scattering layer does not absorb the external light, and the external light either reaches the eyes of the observer or is used for power generation, so the solar cell looks colorful. Moreover, there is a description that the use efficiency of external light can be increased.

In a solar cell module currently in practical use, a photovoltaic force obtained from a photoelectric conversion film is applied to a comb-shaped collecting electrode such as an Ag conductive film formed on a transparent electrode or the like via a transparent electrode or the like. It has conductive films such as Ag, Cu, Ni, Mo and their alloys, carbon black, and graphitized carbon black as part wiring electrodes. As the transparent conductive film, SnO ₂ -doped ITO (tin-doped indium oxide) film, SnO ₂ film (including Sb, F-doped type), ZnO film (including In, Al, Si-doped type) and the like are known. Among them, ITO is generally used, but when laminating an α-Si layer by a plasma CVD method under a reducing atmosphere, a ZnO film is laminated on ITO, and an α-Si layer of a photoelectric conversion film is laminated thereon. Is more preferred. In addition, in addition to this, a multi-stage cell structure for obtaining a desired high voltage on a single substrate, a printed insulating film for patterning necessary for series connection, a dry process, etc. The laser scribe pattern to be formed is performed, and an insulating resin is printed thereon to form a partition wall, or a conductive ink is similarly printed to provide a laser bonding structure. In particular, it is more remarkable than a film solar cell in which an integrated structure is easily formed.) The color tone as viewed from the light receiving surface of the solar cell is such that the interference color of the transparent electrode thin film (which determines most of the color tone of the solar cell) and the color tone of the α-Si photoelectric conversion film are superimposed on a uniform color surface. Patterns of various line widths having optical characteristics such as high light reflectance, high light absorption, high light transmittance, specific wavelength range absorptivity, etc. resulting from the formation of the integrated structure intermingle with each other to hinder harmony of color tone in design. That is the reality.

There is a patterning method in which a transparent electrode formed by a sputtering method, a photoelectric conversion film formed by a plasma CVD method, a metal electrode formed by a sputtering method, and the like are integrated on a substrate using a metal mask without using screen printing or laser scribe. Among these, the metal electrode on the mask shielding part shows a particularly high reflectance, so the high contrast with the light conversion film part of the non-mask shielding part prevents the discomfort even if it is shielded by providing a diffusion transmission layer on the cell top. It is extremely difficult to do.

Therefore, even if a selective reflection layer, a diffusion transmission layer, and the like described in the above-mentioned publication are provided on the upper layer on the light-receiving surface side of the solar cell, the lightness and the lightness are reduced due to the respective optical characteristics.
Various pattern lines differing in color tone, reflectance, and sharpness enter a uniform color surface and appear to rise. Making these various pattern lines inconspicuous is a point that eliminates discomfort in product design due to solar cell mounting,
The solar cell design lacked consideration to give the degree of freedom in product design design up to that point. In particular, the requirements for design are severe, such as in the case of a "solar watch" that can drive a movement by solar cell electromotive force even at low indoor illuminance. Further, when a clock face mainly having a white color and a black color but also having a selective reflection layer of various colors and a diffusion transmission layer is provided in the upper layer on the solar cell light receiving surface side, the gap is also thin. For this reason, it is necessary to make the contact state almost close to the contact state, but it is necessary to satisfy the above-mentioned problem even in such a use condition.

Further, the solar cell module improves the power generation efficiency by using a light source and an illuminance to be used, and improves the battery performance by increasing the voltage according to the requirements of the device to be used by using a multi-stage integrated structure. Technology to expand the solar cell market as a clean energy source, while providing the solar cell product itself or the freedom of design design in consideration of harmony with the surrounding environment. It is an issue.

[0011] In order to solve such a problem, the present applicant has first provided an insulating colored film for reducing the color difference from the photoelectric conversion portion in a portion outside the photoelectric conversion portion on the light receiving surface of the solar cell module. (Japanese Patent Application No. 11-79472). By the way, a solar watch designed using a black dial is popular for outdoor use, especially for sports diver watches and the like. In addition to watches, not only in watches, but also in products with solar cells in general, some consumers prefer black, and white and black dials are the mainstream among various dials. Occupy.

It is considered that a black filter may be simply used to blacken the solar cell mounting portion including the black dial portion of the timepiece. However, in order to increase the blackness, a filter having a strong blackness is used. When the (dial) is used, the black filter absorbs a large amount of light over the entire light wavelength range of 400 to 700 nm, which corresponds to a visible color sensation, and is cut by the upper dial before reaching the solar cell, and the illuminance of light Is extremely small, and there is a problem that the amount of power generation as a solar cell is very small and the function is deteriorated.
Therefore, it is not merely necessary to use a black filter, but it is necessary to achieve both blackness and solar cell function. For this purpose, a black filter with translucency is used as the dial, and the light necessary to operate electronic devices such as watch movements, while maintaining the black dial's visible reflectance and base concealment. Transmission must also be ensured. Black color that looks like jet black is required for design, but for applications such as solar watches using solar cells, a light transmittance of at least 25 to 40% is secured, and photovoltaic properties and design are required. It is indispensable to ensure the blackness of the filter and the concealing property without being aware of the existence of the filter base, especially the solar cell.

As a method of obtaining a colored solar cell, there is also a proposal of providing a white diffusing means or a specific wavelength absorbing light diffusing layer between the color filter and the solar cell.
No. 9646, No. 5-38464, No. 7-17
No. 6799). However, in this method, the diffused layer, in which the incident light is white or white due to Rayleigh scattering or the like, is inserted directly below the filter. It has a color tone that deviates from jet black, which is desired for its design.

[0014]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photovoltaic module having a light-receiving surface having a black color tone so as to be suitable for a black clock face, etc. In addition, the harmony in design is maintained, there is no sense of incongruity, the degree of freedom in design design is provided, it is stable against environmental changes such as temperature and humidity outdoors and indoors, and the dimensional accuracy is high It is to provide a solar cell module.

[0015]

According to the present invention, a slightly blue-colored non-diffusible layer having a transmittance of preferably 80% or more in a visible light wavelength region is replaced with a black light-diffusing layer in place of the above-mentioned light diffusing layer. It is provided between the filter and the photoelectric conversion layer of the solar cell. As a method that can be expected to have the same effect as the above-mentioned non-diffusible layer, a transparent collector electrode thin film (thickness of about 500 to 900 °) provided on a photoelectric conversion film using an α-Si layer, which is provided thereon, can be obtained. Utilizing the color tone (for example, blue-violet) developed on the thick side due to interference reflection of light and the transparent brown color of the photoelectric conversion film itself, for example, utilizing a blue-violet black, the black design and the power generation characteristics of the solar cell Has been realized.

In this case, the inorganic thin film such as the transparent conductive film and the α-Si photoelectric conversion film exhibits a slightly metallic luster color and a portion other than the photoelectric conversion portion on the light receiving surface of the cell, although not as much as the metal base electrode. Meets the design requirement that the black color tone becomes uniform when the entire insulating colored film is as close to the color difference as possible when viewed from the light-receiving surface through the dial, and does not degrade the power generation characteristics and does not diffuse blue Fine particles of white pigments (silicon oxide, calcium carbonate, alumina, titanium oxide, etc.) to such an extent that the excellent black color of the conductive layer is not impaired (for example, total light transmittance of 85%, diffuse transmittance of 44% or less, haze of 52% or less). May be uniformly mixed in the blue non-diffusion layer, or a layer in which fine particles are uniformly mixed together with a binder may be provided below and between the photoelectric conversion unit.

That is, the present invention is as follows. (1) In a solar cell module having silicon and having a photoelectric conversion unit for converting incident light incident from the light receiving surface into electricity, a portion of the solar cell module located on the light receiving surface side with respect to the silicon of the photoelectric conversion unit has a black color. A solar cell module having a colored layer and a blue colored layer between the black colored layer and the silicon. (2) The total visible light transmittance of the blue colored layer is 7
5-90%, diffuse transmittance 1.0-45%, haze 1.
The solar cell module according to the above (1), which is a non-diffusible layer of 0 to 60%. (3) The total visible light transmittance of the blue colored layer is 8
The solar cell module according to the above (2), which is a non-diffusible layer having 0 to 90%, a diffuse transmittance of 1.0 to 9.0%, and a haze of 1.5 to 9.0%. (4) The solar cell module according to any one of (1) to (3), wherein the blue colored layer has a light transmittance of 70% or more in a wavelength range of 400 to 650 nm. (5) The solar cell module according to any one of (1) to (3), wherein the blue colored layer has a light transmittance of 80% or more in a wavelength region of 400 to 700 nm. (6) The total visible light transmittance of the black colored layer is 2
The solar cell module according to any one of the above (1) to (5), wherein the solar cell module is a layer having 5 to 40%, a diffusion transmittance of 0.5 to 26%, and a haze of 2.0 to 82%. (7) The total visible light transmittance of the black colored layer is 2
The solar cell module according to the above (6), which is a layer having a thickness of 5 to 37%, a diffuse transmittance of 0.5 to 13%, and a haze of 2.0 to 35%. (8) The solar cell module according to any one of (1) to (7), wherein the blue colored layer is provided as a resin film or sheet. (9) The solar cell module according to any one of (1) to (7), wherein the blue colored layer is a protective coating film provided on the photoelectric conversion unit. (10) The solar cell module according to any one of (1) to (9), wherein the thickness of the blue colored layer is 5 to 100 μm.

(11) The solar cell module according to any one of (1) to (10), wherein the black colored layer is provided as a resin film or sheet. (12) The thickness of the black colored layer is 300 to 1000 μ
m, the solar cell module according to any one of the above (1) to (11). (13) An insulating colored film is provided at a portion other than the black colored layer and the photoelectric conversion portion, and the insulating colored film reduces a color difference between the photoelectric conversion portion and a portion other than the photoelectric conversion portion. The solar cell module according to any one of 1) to (12). (14) The insulating colored film according to (1), wherein pigment particles and / or dyes are dispersed in a binder.
3) The solar cell module. (15) The solar cell module according to (14), wherein the insulating colored film also serves as a blue colored layer in which blue pigment particles and / or dyes are dispersed in a binder. (16) The above (14) or (1) having a white fine particle pigment as the pigment particles dispersed in the insulating colored film.
5) The solar cell module. (17) The solar cell module according to any one of (1) to (16), wherein the photoelectric conversion unit is a non-single-crystal silicon film. (18) The above-mentioned (1), wherein the photoelectric conversion unit includes a transparent conductive film. The solar cell module according to any one of (17) to (17). (19) The interference color of the transparent conductive film caused by the interference reflection of the light reflected on the film surface of the transparent conductive film and the light reflected at the interface between the film and the other film of the photoelectric conversion unit. The solar cell module according to the above (18), wherein the transparent conductive film has a function of controlling the color tone of the blue coloring layer. (20) The transparent conductive film has a refractive index of 1.9 to 2.2.
Wherein the thickness is 500 to 900 Å.

(21) The solar cell according to any one of the above (18) to (20), further comprising an insulating colored film on the transparent conductive film for reducing a color difference between the photoelectric conversion part and a part other than the photoelectric conversion part. Battery module. (22) The solar cell module according to the above (21), wherein the insulating colored film for reducing the color difference has a function of controlling the color tone of the blue colored layer. (23) The above (1) to (22) having a protective coating film having translucency and heat resistance on the photoelectric conversion unit.
Any of the solar cell modules. (24) translucent and heat-resistant resin, glass,
And the solar cell module according to any one of the above (1) to (23), having any one of stainless steel base materials. (25) translucent and heat-resistant resin, glass,
The solar cell module according to the above (24), wherein a hot melt material having a buffer adhesive layer containing a thermosetting resin or a thermoplastic resin is laminated on at least one surface of any one of stainless steel substrates. (26) The solar cell module according to the above (25), wherein the hot melt material is a blue colored layer. (27) The solar cell module according to the above (25) or (26), wherein the hot melt material is laminated on the light-transmitting and heat-resistant protective coating film. (28) The solar cell module according to any one of (1) to (27) used for a timepiece.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The solar cell module of the present invention has silicon, and has a photoelectric conversion unit that converts incident light incident from the light receiving surface into electricity, and a portion located on the light receiving surface side of the photoelectric conversion unit is colored black. A layer is provided, and a blue coloring layer is provided between the black coloring layer and silicon. In this case, the blue colored layer has a total visible light transmittance of 75%.
~ 90%, diffuse transmittance is 1.0 ~ 45%, haze is 1.
It is preferably 0 to 60%, and is a non-diffusible layer having good transparency and low haze. More preferably, the total light transmittance is 80 to 90%, and the diffuse transmittance is 1.0 to 9.0.
% And haze are 1.5 to 9.0%. On the other hand, the black colored layer preferably has a total visible light transmittance of 25 to 40%, a diffuse transmittance of 0.5 to 26%, and a haze of 2.0 to 82%. More preferably, the diffusion transmittance is 0.5 to 9.0%, and the haze is 2.0 to 35%.

Here, the total light transmittance and the diffuse transmittance are JI
The haze was measured in accordance with S K 7105, and the haze was determined from these in accordance with the following formula. Haze (%) = [diffuse light transmittance / total light transmittance] × 1
00

By using such a blue coloring layer and a black coloring layer together, the light receiving surface side of the solar cell, such as a black dial of a watch, is brought to a black color tone, particularly a black color tone close to jet black. be able to. At this time, for example, as compared with a case where a black color tone is obtained using only a black filter, it is easier to increase the degree of blackness without substantially lowering the characteristics as a solar cell. That is, if a filter having a larger blackness suitable for the purpose is used in order to obtain a sufficient blackness, the absorption of light by this filter increases, the light reaching the photoelectric conversion unit of the solar cell is reduced, and the power generation performance is reduced. The problem of deterioration is solved by using the blue non-diffusible layer of the present invention. Although the black colored layer (black filter) used in the present invention has a light transmittance enough to maintain the power generation performance at a practical level, the shortage of the blackness is superimposed on a blue non-diffusion layer having a low color density. There is a feature of the present invention in the supplement. In addition, the blue non-diffusible layer has almost no effect of lowering the power generation performance by controlling the light density and wavelength characteristics of the light to the photoelectric change portion. In particular, in the present invention, amorphous silicon (α-Si) is preferably used as a power generation layer in the photoelectric conversion portion, and the quantum efficiency of the amorphous silicon is maximized in light having a wavelength around 550 nm. The blue non-diffusible layer almost transmits light having a wavelength in the vicinity. The blue colored layer is 4
Light transmittance of 70 to 650 nm (visible region)
% Or more, and preferably has a light transmittance of 80% or more in a wavelength range of 400 to 700 nm (visible region). Further, by subtly changing the blue color of the blue non-diffusion layer, the black color tone can be changed.

This is presumed to be related to the wavelength characteristics of human luminosity, but the reason is not clear.

First, the black colored layer of the present invention will be described. The black colored layer of the present invention is preferably a resin film or sheet (plate), and its thickness varies depending on the purpose and application.
000 μm, and preferably around 500 μm.

[0025] The resin material of such a resin film is not particularly limited, but a resin that is hard and has high optical transparency and does not undergo discoloration and devitrification due to long-term use, particularly, polymethyl methacrylate resin (PMMA). It is often used because of its transparency, hardness and the like. In addition, amorphous polyolefins (ARTON (norbornene resin): manufactured by Nippon Synthetic Rubber Co., Ltd., Zeonor: manufactured by Nippon Zeon Co., Ltd., APO: manufactured by Mitsui Chemicals, Inc.), polyether sulfone (PES: manufactured by Sumitomo Bakelite Co., Ltd.) , Polycarbonate (manufactured by Teijin Chemicals), polyarylate resin (PAR: ELMEC: manufactured by Kanebuchi Chemical Co., Ltd.), and the like.

In order to obtain a black color, a black pigment or a black dye may be kneaded into the film, or a coating solution containing the black pigment or the black dye may be coated on the film or sheet. These pigments and dyes may be uniformly present in the film or the coating print layer, or may be unevenly distributed. In any case, there is no particular limitation as long as the above characteristics are satisfied.

Examples of black pigments include carbon black, fine-particle graphite, chromium oxide, viridian, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, dioxazine pigments, slen pigments, perylene pigments, and perinones. Pigments, thioindigo pigments, quinophthalone pigments, metal complex pigments, and the like.

The average primary particle size of the pigment is 0.1.
It is about 01 to 0.8 μm.

Examples of black dyes include azo dyes, metal complex dyes, naphthol dyes, anthraquinone dyes, indigo dyes, carbonium dyes, quinone imine dyes, xanthene dyes, cyanine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, and naphthoquinone dyes. And oil-soluble dyes such as phthalocyanine dyes and metal phthalocyanine dyes.

These may be used alone or in combination of two or more.

Since the black colored layer (black filter) is often used for outdoor use watches, in general, a fine-particle pigment system well dispersed in a resin is more advantageous than a dye in terms of light resistance or weather resistance. It is.

Further, a commercially available black filter which is suitable for the present invention may be selected and used.

Next, the blue colored layer of the present invention will be described. The blue colored layer of the present invention may be a resin film (or sheet), or may also serve as a protective coating film on a light receiving surface provided with a photoelectric conversion unit. The protective coating film may be a laminate material.
The protective coating film will be described later.

The thickness of the blue colored layer is 5 to 100 μm, regardless of whether it is used as a resin film or a protective coating film, depending on the purpose and application. Is preferred.

When used as a resin film, it may be disposed via an air layer or may be bonded by an adhesive layer.
As the adhesive layer, the same one as the buffer adhesive layer of the hot melt material can be used.

The resin material of such a resin film is not particularly limited, but may be the same as a base material of a hot melt material described later. In particular, polyester films such as polyethylene terephthalate film and polyethylene naphthalate film are preferably used.

Further, to obtain a blue color, a blue pigment or a blue dye may be kneaded into the film, or a coating solution containing the blue pigment or the blue dye may be coated on the film. In any case, it is preferable that these pigments and dyes are uniformly present in the film or the coating layer.

On the other hand, when the protective coating film is to be a blue colored layer, the protective coating film may be formed by incorporating a blue pigment or a blue dye into the coating liquid for the protective coating film. When the laminating material is formed into a blue colored layer, the laminating material may be kneaded into a resin substrate or may be incorporated into the buffer adhesive layer. Further, when a coating film is further provided on the laminate material, a blue pigment or a blue dye may be contained in the coating liquid for coating.

Examples of blue pigments include viridian, ultramarine blue, Prussian blue, cobalt blue, azo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, dioxazine pigments, sllen pigments, perylene pigments, Examples include perinone pigments, thioindigo pigments, quinophthalone pigments, metal complex pigments, and the like.

The average primary particle size of the pigment is 0.1.
It is about 01 to 0.8 μm.

Examples of blue dyes include azo dyes, metal complex dyes, naphthol dyes, anthraquinone dyes, indigo dyes, carbonium dyes, quinone imine dyes, xanthene dyes, cyanine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, and naphthoquinone dyes. And oil-soluble dyes such as phthalocyanine dyes and metal phthalocyanine dyes.

These may be used alone or in combination of two or more.

Of these, phthalocyanine pigments (particularly copper phthalocyanine pigments) are preferably used. Specific examples of phthalocyanine pigments include CI Pigment Blue 16,
Blue 15, Blue 15: 2, Blue 15: 3, Blue 15: 4, Blue 15:
5, Blue 15: 6, Blue 15: 1 and the like. Further, β-type copper phthalocyanine (Cyanine Blue) manufactured by Dainichi Seika is also included.

In order to finely adjust the blue color tone,
Red quinacridone pigments, synchasia red, synchasia purple and the like may be used in combination.

Further, a commercially available blue filter which is compatible with the present invention may be selected and used.

In the present invention, an insulative colored film (which may also serve as a protective coating film) described later in detail may be used as a functional film as a so-called non-diffusively permeable spacer filter as described above. . When an insulative colored film is used for this purpose, it is preferably provided also on the transparent conductive film of the photoelectric conversion portion, and is preferably provided so as to cover the entire cell. Fine particles of a white pigment (silicon oxide, calcium carbonate, alumina, titanium oxide, etc.) are uniformly mixed or white to the extent that the optical properties of the blue non-diffusible layer having a ratio of 44% or less and a haze of 52% or less can be maintained. A binder layer in which pigment fine particles are uniformly dispersed may be provided as a lower layer (however, an upper layer above the photoelectric conversion unit). The specific configuration is as described below, except for the optical characteristics and the pigment used. The pigment used here may be selected from those described below. The upper limit of the total light transmittance, the lower limit of the diffuse transmittance and the lower limit of the haze are the same as described above.

In the present invention, the transparent conductive film is used as it is, and the blue interference color (that is, the light reflected on the surface of the transparent conductive film and the interface between the transparent conductive film and the underlayer) is obtained by controlling the film thickness. (Obtained by interference reflection of reflected light) may be used as a functional film of a non-diffusible blue colored layer. When utilizing the blue interference color, about 800 for ITO
It must be about と す る thick. Also in such an embodiment, it is visually recognized that the black filter exhibits a color tone with a high degree of blackness by being placed. In this case, if necessary, a film functioning as a non-diffusible spacer filter or a protective coating film may be used in combination.

For applications requiring blackness rather than using a black filter on the uppermost light-receiving surface side, it is preferable to use a blue non-diffusible filter layer. In addition to the film filter layer, a surface protective resin film of a cell photoelectric conversion film is preferably used. Is also effective. Examples of such protective resin film materials include epoxy resins, phenoxy resins, saturated polyester resins, fluorinated solvents, melamine resins such as n-butylated melamine and methylated melamine, and hexamethylene diisocyanate. Non-yellowing trimeric polyfunctional isocyanates such as isophorone diisocyanate, and low-temperature reactive blocked isocyanates obtained by blocking methyl ethyl ketone (MEK) oxime and ethyl acetoacetate exhibiting keto-enol type tautomerism with polyfunctional isocyanates The colored film of the cross-linkable light-transmitting protective film is also effective. Further, a method using an interference transparent reflection film of an ITO transparent conductive film used as a photoelectric conversion film of a solar cell is also effective for coloring without deteriorating characteristics, and a micro-reflection spectral film thickness meter (FTM-1000 manufactured by Otsuka Electronics Co., Ltd.) The ITO film provided on the Al reflective film of the base electrode by
Å indicates blue reflected interference light.

It should be noted that α-
When silicon is used, the wavelength range in which the quantum efficiency is maximized is around 550 nm, so that a colored layer with less absorption of light of such a wavelength is provided as an upper layer on the light-receiving surface side,
It is preferable because the tint can be added without lowering the battery performance. As such a colored layer, a green to green-yellow colored layer is promising. The green to green-yellow colored layer has a total visible light transmittance of 60 to 80% and a diffuse transmittance of 1.5 to 2.5.
%, And a layer having optical characteristics of haze of 2.0 to 4.0%.

Such a colored layer is preferably a resin film layer, and its thickness varies depending on the purpose and application.
In particular, the thickness is preferably 5 to 100 μm for use in a clock face.

As a resin material of such a resin film layer,
Although there is no particular limitation, a film film similar to a substrate of a hot-melt material to be described later, or a film material of the same material as a photoelectric conversion film layer and a protective film layer of a solar cell may be used. In particular, as the film layer material, a polyester film such as a polyethylene terephthalate film or a polyethylene naphthalate film is preferable in terms of versatility and economy. In particular, when optical transparency is required, polyethersulfone (PES), amorphous polyolefin and the like are preferable. For extremely severe environmental resistance use, polymethyl methacrylate resin (PMMA) having ultraviolet light cut property, tetrafluoride Ethylene-ethylene copolymer (ETFE), polyvinylidene fluoride (PFVD) and the like are used.

In order to obtain a green color, a green pigment or a green dye may be kneaded into the film, or a coating solution containing the green pigment or the green dye may be coated on the film.

Green pigments include titanium cobalt green, viridian, azo pigments, phthalocyanine pigments (for example, CI Pigment Green 7, Green 36), quinacridone pigments, isoindolinone pigments, dioxazine pigments, sulene pigments, There are perylene pigments, perinone pigments, thioindigo pigments, quinophthalone pigments, metal complex pigments and the like.

The average primary particle size of the pigment is 0.1.
It is about 01 to 0.8 μm.

Green dyes include azo dyes, metal complex dyes, naphthol dyes, anthraquinone dyes, indigo dyes, carbonium dyes, quinone imine dyes, xanthene dyes, cyanine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes And oil-soluble dyes such as phthalocyanine dyes and metal phthalocyanine dyes.

These may be used alone or in combination of two or more.

For outdoor applications, pigments are preferred.

Further, a commercially available green filter which is suitable for the present invention may be selected and used.

Further, as a method for coloring the solar cell, an interference color obtained by changing the thickness of the transparent conductive film may be used.
By controlling the film thickness from about Å to about 800 は じ め for the first time, coloring such as red, purple, magenta and blue becomes possible.

When ITO is used for the transparent conductive film, the color tone of the solar cell is determined by the interference reflection color of the ITO film. When the interference reflection color of the ITO film is used, the color of the ITO film (that is, the solar cell) is used. The relationship between the color tone and the thickness of the ITO film is shown. When ZnO is used for the transparent conductive film, the refractive index n is almost equal to that of ITO and is about n = 2, and therefore, it is considered that ZnO exhibits the same color tone.

Color of ITO film (that is, solar cell) Thickness of corresponding ITO film (Å) Brown 530 Brown purple 600 Purple 700 Blue 800 Light blue 900

The thickness of the transparent conductive film (transparent electrode) in the solar cell module of the present invention is 500 to 900 °.
And the refractive index is preferably 1.9 to 2.2.

The solar cell module of the present invention has a photoelectric conversion unit for converting incident light into electricity, and the photoelectric conversion unit contains silicon. It is preferable that an insulating colored film is provided at a portion other than the photoelectric conversion portion, and the insulating colored film reduces a color difference from a photoelectric conversion portion obtained by reflection of at least light containing light in a visible light region. Let me.

The photoelectric conversion portion corresponds to a so-called power generation layer. In a solar cell, usually, a single crystal Si or a polycrystal S
i, or amorphous Si (α-Si) or the like,
A predetermined impurity is added to this and a pn junction or pi junction is added.
An n-junction is formed. Above all, polycrystalline Si, α
-Si is preferred, and α-Si is particularly preferred.

The light receiving surface of the solar cell is a surface on which light necessary for light-to-electric conversion is incident.

The portion other than the photoelectric conversion portion refers to various structures or structural films required for the power generation function of the solar cell other than the photoelectric conversion portion, and is, for example, an insulating pattern or a conductive pattern. More specifically, a collecting electrode such as Ag / graphite / carbon conductive film, or Ag as an outer peripheral wiring electrode
(Cu, Cu compound, Ni, Mo, Al used together with Ag
Thin films and fine particle dispersion films of carbon black, graphitized carbon black, etc., and conductive films in which the metal fine particles and carbon fine particles are mixed, ITO (tin-doped) Indium oxide), ZnO, S
It is a transparent electrode such as nO ₂ , a printed insulating film or the like.

The insulative colored film reduces the color difference from the photoelectric conversion unit. Specifically, the color difference ΔE is preferably 3.0 or less, more preferably 2.5 or less when the black resin plate is installed, and the lower limit is not particularly limited. That is, this insulating colored film
When the film formation surface is observed from the outside together with the color and the reflectance of the base portion, the color difference ΔE from the photoelectric conversion unit is preferably adjusted to be 3.0 or less. A close color insulating ink is applied and formed.

Also, a conductive pattern as a portion other than the photoelectric conversion portion, more specifically, a comb-shaped collecting electrode such as an Ag conductive film, or Ag (Cu, Cu used in combination with Ag) as an outer peripheral wiring electrode Compound, metal thin film represented by Ni, Mo, Al and conductive film of fine metal particles), carbon black, graphitized carbon black, etc., a thin film or fine particle dispersed film by dry process, and a mixture of the fine metal particles and fine carbon particles. The color of these conductive films themselves may be adjusted so that the color difference between the conductive film and the photoelectric conversion unit falls within the above range.

The color difference ΔE is generally expressed in NBS units (National
Bureau Standards), L ^* , a ^* , b
^* Display system brightness on (JIS-Z8722, JIS-Z8727 tristimulus values x defined by, y, index can be calculated from z) L ^*, redness a ^*, blue b ^*, each, Difference ΔL, Δ between the part where the insulating colored film is applied and the photoelectric conversion part
a and Δb can be obtained as follows.

ΔE = [(ΔL) ² + (Δa) ² + (Δb) ² ] ^1/2 The smaller the value of ΔE, the closer they are to each other. Usually, when ΔE exceeds 3.0, a difference is clearly recognized, and when ΔE is 12.0 or more, a completely different kind of color is considered.

The insulating colored film is preferably such that pigment particles are dispersed in a binder. A pigment particle dispersion film having low reflectance and diffusely reflecting even in the presence of reflected light is particularly preferred.

As the binder, some weather resistance,
Various structures required for the power generation function of the solar cell other than the photoelectric conversion portion, such as light resistance, etc., are particularly limited as long as they have good binding properties with the structural film and good dispersibility of the pigment particles. Not something. When a portion other than the photoelectric conversion portion is covered by patterning by a screen printing method, an oil-soluble resin is more desirable than a water-based emulsion in terms of good wettability with a dry lower layer of the film. As the oil-soluble resin, for example, an epoxy resin, particularly a phenoxy resin, an amorphous polyolefin resin (for example, Arton: manufactured by Nippon Synthetic Rubber Co., Ltd.), desirably a polyisobutylene resin or a vinyl resin, desirably ethylene -Vinyl acetate copolymer resin, vinyl chloride-
Vinyl acetate copolymer resin or vinyl acetate resin or ethylene-vinyl chloride-vinyl acetate resin; and acrylic resin, preferably methacrylate resin, polyacrylate resin, ethylene-ethyl acrylate copolymer resin or ethylene-methacrylic acid copolymer. Phenolic resin; polyurethane resin; polyamide resin; polyester resin (especially saturated polyester resin)
Or; ketone resin; alkyd resin; rosin resin;
Hydrogenated rosin resin, petroleum resin, hydrogenated petroleum resin, maleic acid resin, butyral resin, terpene resin, hydrogenated terpene resin, chroman-indene resin, and the like. Particularly, phenoxy resin, Epoxy resins, urethane resins, saturated polyester resins and the like are preferred. These include weather resistance obtained by the crosslinking, mechanical strength as a composite material film in which the material is dispersed, organic materials such as an ink film and a base film serving as a base, and inorganic materials such as ITO and α-Si. It is an excellent resin in terms of adhesion to a thin film, stability against environmental changes during long-term use, and the like, and has a great degree of freedom in designing a molecular structure. These resins (polymer materials) may be used alone or in combination of two or more.

The pigment particles are not particularly limited as long as they can obtain a predetermined color close to the color of the material of the photoelectric conversion portion. One or more pigments having high hiding power and coloring power can be used. It may be adjusted by using. Specifically, high hiding power, titanium dioxide or a white or nearly colorless fine particle pigment, zinc oxide, kaolin, clay,
Calcium carbonate, barium carbonate, calcium sulfate, barium sulfate, magnesium carbonate, silica, alumina, diatomaceous earth, etc., as well as high coloring power such as red iron oxide, carbon black, fine graphite, Prussian blue, cobalt blue, phthalocyanine pigment, and synchasia red , Synchasia violet and the like are preferably used in combination. In particular, rutile titanium dioxide (Ti) having high hiding power and high whiteness
When O ₂ ) is mixed, it is possible to obtain a pastel intermediate color that is effective for hiding the light-receiving surface serving as a base and is close to a diffusive hue of the base color.

The iron oxide fine particles having coloring power are used to match the color tone of a solar cell having a structure in which an ITO transparent electrode is laminated on an amorphous silicon thin film or the like.
It is preferable because it has a wide selection range of brown, red, and black tones and has light resistance and weather resistance like titanium dioxide.

By controlling the color tone by using such a coating film in which pigments or pigment particles are dispersed, incident light is diffused and reflected appropriately, which is advantageous for unifying the color tone of the entire cell. For example, in order to prevent a large contrast difference between the site due to the high reflectance of the metal-based colored thin film of the non-photoelectric conversion site concealed by the mask pattern by the dry process and the photoelectric conversion site, the non-photoelectric conversion site is used. It is preferable to provide a pigment-dispersed color tone control coating film on the light receiving side uppermost portion of the cell by a screen printing method so as to cover the cell.

In addition, if necessary, carbon black, cadmium red, molybdenum red, chrome yellow, cadmium yellow, titanium yellow,
Chromium oxide, viridian, titanium cobalt green, ultramarine blue, Prussian blue, cobalt blue, azo pigment, phthalocyanine pigment, quinacridone pigment, isoindolinone pigment, dioxazine pigment, sllen pigment, perylene pigment, perinone Pigments,
The color may be adjusted using a conventionally known pigment such as a thioindigo pigment, a quinophthalone pigment, a perylene malene pigment, or a metal complex pigment.

For example, monocrystalline silicon as a solar cell,
When using polycrystalline silicon, Prussian blue,
It is effective to use a cobalt blue or phthalocyanine pigment alone or as a main component pigment for uniform color tone.

A dye may be used in place of or in combination with the above pigment, but it is preferable to use a pigment. As the dye, azo dye, metal complex dye, naphthol dye, anthraquinone dye, indigo dye, carbonium dye, quinone imine dye, xanthene dye, cyanine dye, quinoline dye, nitro dye, nitroso dye, benzoquinone dye, naphthoquinone dye, phthalocyanine dye, Examples thereof include oil-soluble dyes such as metal phthalocyanine dyes.

The average particle size of the primary particles of the pigment is set to 0.1.
It is about 01 to 0.8 μm. The mixing amount of the pigment with respect to the binder is preferably about 30 to 500 wt%, more preferably about 50 to 380 wt%.

As means for providing an insulating colored film, a color insulating ink obtained by dissolving and dispersing the above binder and pigment particles in a dispersion medium is applied to a predetermined region of the light receiving surface of the solar cell.
It may be applied by a screen printing method or the like. The thickness of the coating film is about 5 to 30 μm when the base is other than the Ag paste electrode film having a high reflectance, and when the base is other than metal,
It is about 3 to 25 μm.

The dispersion medium is preferably a solvent capable of dissolving and dispersing the above-mentioned binder, pigment and the like, and not dissolving or corroding the structure on the surface of the solar cell. Specifically, cyclohexanone, isophorone, γ-butyrolactone, N-methylpyrrolidone, terpineol, octane, isooctane, decane, isodecane, decalin, nonane, dodecane, isododecane, cyclooctane, cyclodecane, benzene, toluene, xylene, mesitylene, isoperene E, Isopar G, Isopar H, Isopar L (Isoper; trade name of Exxon), Shelsol 70, Shersol 71 (Shelsol, trade name of Shell Oil), AMSCO OMS, AMSCO 460
Solvents (Amsco; trade name of Spirits), acetates such as butyl carbitol acetate, butyl cellosolve acetate, and the like. These may be used alone or in combination of two or more. The amount of the binder and the pigment added to the dispersion medium is about 40 to 180% by weight.

In addition to these, if necessary, a dispersant,
Additives such as an antifoaming agent and a leveling agent may be mixed. These additives are usually added in a total amount of about 20% by weight or less.

Next, the solar cell of the solar cell module of the present invention will be described. For example, as shown in FIG. 4, the solar cell of the present invention includes a lower electrode 2
It has a silicon-containing layer 3 such as α-Si having an n-junction, a pin junction, or the like, an insulating layer 4, and a transparent electrode 5 such as ITO. Also, a first element isolation layer 6 and a second element isolation layer 7
And a wiring electrode 8 and a lower extraction electrode 9. FIG. 4 is a partial cross-sectional view showing one configuration example of the solar battery cell.

In such a solar cell, the light incident on the photoelectric conversion portion via the transparent electrode 5 reaches the silicon-containing layer 3 and the electromotive force generated inside the silicon-containing layer 3 causes the lower electrode 2
And a region that can be extracted through the transparent electrode 5. The other portions refer to the insulating layer 4, the first element isolation layer 6, the second element isolation layer 7, the wiring electrode 8, and the like.
These portions do not contribute to power generation and are made of a material different from that of the photoelectric conversion unit. For this reason, these structural members are in a region visible from the outside, and if the difference is clear, control over the design will be impaired.
Therefore, the insulating colored film 11 is provided in these portions,
By controlling the color difference to a predetermined value or less, control and harmony in design can be ensured. A non-diffusible blue colored layer (not shown) is provided thereon as a protective film or a film, and a black colored layer (not shown) is further provided. This is the same in FIG. However, when the transparent electrode 5 functions as a non-diffusible blue colored layer, the provision of the non-diffusible blue colored layer may be omitted.

Further, as shown in FIG. 5, for example, in a circular solar cell 21, a photoelectric conversion unit 22 and an element for separating the photoelectric conversion unit into a series connection structure for increasing the voltage of the cell. The separation unit 23, the connection units 27, 28, and 29 having a serially connected wiring structure, the extraction electrode unit 25,
26. The element separating section 23 is usually
2, the color becomes lighter, and the connection parts 27, 28, 29,
Extraction electrode portions 25, 2 partially penetrating the bottom surface
6 is a metal color for a wiring electrode having a high reflectivity when a conductive Ag paste is used. Even when such a structure is located at a site that can be visually recognized from the outside, the design control is impaired. In particular, when using solar cells for the clock face, the requirements required for design are strict,
More control and harmony is required. Therefore, by providing the insulating colored film also at these portions, the color difference can be reduced to a predetermined value or less, and control and harmony in design can be ensured. In the case where the reflectance of the base is high, such as a metal portion, an ink film having a high concealing property including overcoating may be used, for example, a thick film of about 30 μm.

After the solar cell is provided with the insulating colored film, a surface coating member or a sealing member is provided to protect the cell structural member from mechanical damage, oxidation, corrosion and the like. Is preferred. Among these protective members, it is particularly preferable to seal with a lamination film. As a particularly preferable lamination film, there is a sealing using a hot melt material described below.

In order to reduce the cost of the solar cell module, a transparent resin protective coating may be used in an allowable field in view of the balance with the environmental resistance of the cell. That is, for example, the protective film may be formed using only a transparent insulating film or the like disclosed in JP-A-11-140147, which is obtained by thermosetting a phenoxy resin with a melamine resin.

When lamination is performed and a lamination film layer is formed on the surface of the solar cell,
At least only the thick portion of the transparent laminate film substrate (for example, 50 to about 100 μm) has the same effect as providing a gap between the outermost surface of the light receiving portion of the cell body and the back of the dial. Thus, the degree to which the color tone of the solar battery cell is transmitted through the dial and visually recognized is reduced by the light diffusion effect of the dial, which is advantageous. Therefore, in the solar battery cell in which such lamination sealing is performed, the significance of providing the insulating colored film is particularly significant.

The hot-melt material used in the present invention has a buffer adhesive layer containing a thermosetting resin on at least one surface of a substrate made of a resin having a light transmitting property and heat resistance. In addition, the substrate may be glass or stainless steel.

By providing a buffer adhesive layer of a thermosetting polymer having rubber elasticity, which is a soft resin having a high cross-linking density between polymer molecular chains, on a resin base material, buffer adhesion to temperature and humidity changes can be achieved. Since the change rate of the mechanical properties of the layer is small and the change is slow, the function as the buffer adhesive layer can be maintained for a long time. Further, the resin protective film has a glass transition point Tg of 65 ° C. or more or a heat-resistant or continuous operating temperature of 8 ° C.
Since a resin film that satisfies one or both of 0 ° C. or more and has a light-transmitting property is used, the performance does not deteriorate even when directly exposed to a light source such as sunlight and heated.

As the resin base material having a glass transition point Tg of 65 ° C. or more and / or a heat-resistant temperature of 80 ° C. or more and having light-transmitting and heat-resistant properties, polyethylene terephthalate film (Tg 69 ° C.), polyethylene naphthalate heat-resistant film (Tg 113 ° C.) ); Fluorinated ethylene resin [PC
TFE: NEOFLON CTFE (manufactured by Daikin Industries, Ltd.)]
(Heat-resistant temperature 150 ° C), polyvinylidene fluoride [PVDF: Denka DX film (manufactured by Denki Kagaku Kogyo)] (heat-resistant temperature 150 ° C: Tg 50 ° C), polyvinyl fluoride (PVF: Tedlar PVF film (manufactured by DuPont)) (A heat-resistant temperature of 100 ° C.), an ethylene tetrafluoride-perfluorovinyl ether copolymer [PFA: neoflon: PFA film (manufactured by Daikin Industries, Ltd.) (heat-resistant temperature: 260 ° C.), ethylene tetrafluoride-6-fluoro Propylene copolymer [FEP: TOYOFLON film FEP type (manufactured by Toray Industries, Inc.)] (heat resistant temperature 200
° C), ethylene tetrafluoride-ethylene copolymer [ETF
E: Tefzel ETFE film (manufactured by DuPont) (heat resistant temperature: 150 ° C.), AFLEX film (manufactured by Asahi Glass: T
g83 ° C.)]; aromatic dicarboxylic acid-bisphenol copolymer aromatic polyester polyarylate film (PAR: casting (ELMEC, manufactured by Kaneka Chemical Co., Ltd.) (heat-resistant temperature: 290 ° C .: T
g 215 ° C.), [Polymethyl methacrylate film [PMMA: Technoroy R526: Tg: 101 ° C. (manufactured by Sumitomo Chemical Co., Ltd.)]]; polysulfone [PSF: Sumilite F
S-1200 (manufactured by Sumitomo Bakelite)] (Tg190
℃), polyether sulfone (PES: Sumilite FS)
-1300 (Sumitomo Bakelite)] (Tg 223 ° C); polycarbonate film [PC: Panlite (manufactured by Teijin Chemicals Ltd.)] (Tg150
° C); functional norbornene resin [ARTO
N (Japanese synthetic rubber)] (Heat-resistant temperature 164 ° C: Tg171
° C); polymethacrylate resin (PMMA) (Tg93
C); olefin-maleimide copolymer [TI-160
(Manufactured by Tosoh Corporation)] (Tg 150 ° C or more), para-aramid (Aramika R: Asahi Kasei) (heat-resistant temperature 200 ° C), fluorinated polyimide (heat-resistant temperature 200 ° C or more), polystyrene (Tg 90 ° C), polyvinyl chloride (Tg 70 to 80)
° C) and cellulose triacetate (Tg 107 ° C). Above all, polyethylene naphthalate heat-resistant film (Tg 113 ° C) has less heat resistance (Tg), heat resistance for long-term use, Young's modulus (stiffness), breaking strength, heat shrinkage, less oligomers, and gas barrier properties when compared with PET. Has excellent performance in terms of hydrolysis resistance, water vapor transmission rate, thermal expansion coefficient, physical property deterioration due to light, etc., and when compared to other polymers, breaking strength, heat resistance, dimensional stability, moisture permeability It is excellent and preferable in terms of overall balance of cost and the like.

The glass transition point Tg of the resin substrate is 65 ° C. or higher, preferably 70 ° C. or higher, more preferably 80 ° C. or higher, and particularly 110 ° C. or higher. The upper limit is not particularly limited, but is usually about 130 ° C. It is. Further, the heat-resistant temperature or the continuous use temperature is 80 ° C. or more, preferably 100 ° C.
As described above, the temperature is preferably 110 ° C. or higher, and the upper limit is preferably higher, and is not particularly limited.
It is about ° C. The thickness of the resin substrate is appropriately determined depending on the member to be laminated, required strength, bending rigidity, and the like, but is usually in the range of 5 to 100 μm, preferably 20 to 90 μm. When the thickness of the resin base material is small, it is difficult to obtain the effect of protecting the surface, and the hot melt material may be deformed after the application of the adhesive layer. When the film thickness increases, the fine particles A
In a film containing l ₂ O ₃ , SiO _2, etc., the light transmittance is reduced, the laminability in a roll state is reduced, and continuous production becomes difficult. Further, the rate of change of the dynamic elastic modulus at 0 ° C. and / or 120 ° C. after thermocompression bonding is preferably within 30%, more preferably within 20%. Its absolute value is 1 × 10 ⁹ to 1 × 10 ¹² dyn / cm ^2.
Is preferable. When the rate of change of the dynamic elastic modulus at 0 ° C. or 120 ° C. after thermocompression bonding exceeds 30, internal stress acts beyond the buffering action of the buffer adhesive layer, resulting in a decrease in adhesive strength, peeling of hot melt material, and laminate. Deformation and the like easily occur.

Note that having translucency means transmitting 70%, preferably 80% or more, of light in the visible light region.

The resin substrate has an MOR showing the degree of molecular orientation.
The value (Molecular Orientation Ratio) is preferably 1.0 to 3.0, more preferably 1.0 to 2.0, and particularly preferably 1.0 to 1.8. When the MOR is within the above range, the deformation of the laminate is reduced. The MOR value indicating the degree of molecular orientation is, for example, Compatec 199
8.3 “Quality control of films and sheets using microwave molecular orientation meter” Shigeyoshi Osaki, Seikei-Kakou Vol.7 No.11
1995 "Molecular orientation behavior associated with biaxial extension" is described in the literature by Yasunobu Zushi, Takahiro Niwa, Sadao Hibii, Shinichi Nagata, Tachi, etc. The greater the MOR value, the greater the anisotropy, with 1.0 being the most isotropic.

Regarding the degree of molecular orientation, even in the same resin film, the MOR value may differ depending on the portion. In particular, in a film manufactured by the biaxial stretching method, the degree of orientation tends to be high at an end portion held for stretching. For this reason, even if the resin is excellent in the degree of molecular orientation, it may be used after checking the degree of molecular orientation in each part of the resin film to be used and confirming that it is within the above-mentioned degree of orientation.

The MOR can be measured, for example, by measuring the transmitted microwave intensity while rotating the sample. That is, the interaction between the microwave electric field of a certain frequency and the dipole constituting the polymer substance is related to the inner product of the vectors of the two, and when the sample is rotated in the microwave polarized electric field, the dielectric constant Due to the anisotropy of
The transmitted microwave intensity changes, and as a result, the degree of molecular orientation can be known. As the microwave used for the measurement,
Although not particularly limited, for example, 4 GHz, 12 GHz
And so on. As a measuring instrument applying such a principle, for example, a molecular orientation meter MOA-50 manufactured by Shin-Oji Paper Co., Ltd.
01A, 5012A, MOA-3001A, 3012A
Etc. In addition, it can also be determined by X-ray diffraction, infrared dichroism, polarized fluorescence, ultrasonic, optical, NMR, or the like.

It is preferable that the above-mentioned degree of molecular orientation be in the above range also for the constituent material of the laminated body using the hot melt material, for example, a flexible substrate.

As the thermosetting resin component of the buffer adhesive layer containing a thermosetting resin and an organic peroxide, an ethylene-vinyl acetate copolymer [EVA (vinyl acetate content of 15 to 5)
About 0%)].

The organic peroxide may be any one as long as it decomposes at a temperature of 80 ° C. or more, particularly 90 ° C. or more to generate radicals. Decomposition temperature for 10 hours is 70 ° C
The above are preferred. As such a thermosetting organic peroxide, for example, 2,5-dimethylhexane-2,5
-Dihydroperoxide; 2,5-dimethyl-2,
5-di (t-butylperoxy) hexane-3; di-t
-Butyl peroxide; 2,5-dimethyl-2,5-
Di (t-butylperoxy) hexane; dicumyl peroxide; α, α'-bis (t-butylperoxyisopropyl) benzene; n-butyl-4,4-bis (t-
Butylperoxy) valerate; 2,2-bis (t-butylperoxy) butane; 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane;
t-butyl peroxybenzate; benzoyl peroxide; and the like. One or more of these may be used in combination, and the mixing ratio at that time is arbitrary. The compounding ratio of the thermosetting organic peroxide to 100 parts by weight of the polymerization component is preferably 10 parts by weight or less, more preferably 0.5 to 6 parts by weight.

Further, in a solar cell used in a living space of a human where the use environment is relatively gentle, some thermoplastic hot melt agents can be used. Examples thereof include (1) polyvinyl butyral resin, (2) ionomer, and (3) low melting point thermoplastic fluororesin (THV manufactured by Dyneon USA): a copolymer of three kinds of monomers of tetrafluoroethylene / hexafluoropropylene / vinylidene fluoride. Polymer). All of these have a high light transmittance in the visible region, do not contain a plasticizer, have good adhesion to the substrate film as a thermoplastic buffer adhesive, and a general-purpose laminator eliminates processing steps such as heat crosslinking and is simple. Thermoplastic sealing can be performed, cell sealing can be performed while maintaining some degree of weather resistance, heat resistance, moisture resistance, surface protection, and the like, and processing cost can be reduced.
In particular, (3) THV manufactured by Dyneon Co. of the United States is superior in “flame retardancy”, “moisture resistance” and “weather resistance” by making use of the characteristics of fluororesin among thermoplastic hot melt agents, and is a general-purpose laminator as compared with ETFE and the like. The advantage of being able to seal the thermoplastic laminate on the surface of the solar cell at a heating temperature of
Absorbent is required).

In order to cover long-term weather resistance such as outdoor exposure, the above-mentioned THV has an electron beam curing property, and a flexible solar cell sheet sealed with a thermoplastic hot-melt material laminated is roll-to-roll. ) Is suitable for the irradiation of the optimal dose by the electron beam irradiation system, especially when the solar cell is manufactured as a building material integrated solar cell.

Further, if necessary, an ultraviolet absorber may be added. By adding an ultraviolet absorber, it is possible to prevent the light resistance of the film itself from ultraviolet light and to prevent the thin film constituting the photoelectric conversion portion such as α-Si from deteriorating due to light. Above all, by adding an ultraviolet absorber, α
The photodegradation phenomenon peculiar to the -Si power generation film also becomes somewhat slow at a low illuminance of 200 Lux (with respect to the light irradiation time). In particular, when the polymer film is disposed on the light-receiving surface side, a benzophenone-based or benzotriazole-based UV absorber having an ultraviolet light shielding function is provided on the light-receiving surface side or inside the polymer, and further, is represented by crosslinkable EVA. Such a buffering adhesive layer, surface treatment or mixing,
It is good to mix.

As the ultraviolet absorber, various aromatic organic compounds can be used. In particular, even if the compounds having the following names or structural formulas are used for a long period of time, yellowing, bleeding out to the film surface, and the like may occur. Less advantageous. Of these, benzotriazoles are particularly preferred. Further, zinc oxide (ZnO) fine particles may be used in the same manner as a chemically stable inorganic ultraviolet absorber.

Further, ZnO fine particles were dispersed in a xylene solution of perhydropolysilazane (number-average molecular weight Mn = 600 to 2,000) (NV120 manufactured by Tonen Co., Ltd.), and a film was formed on the polyether sulfone resin film. 0.5
The coated film is heated to 150 ° C and oxidized with steam at 90 ° C (80% RH) for 1 hour (using a 5 wt% aqueous solution of trimethylamine as a catalyst) to form a dense transparent silica thin film at low temperature. I do. At this time,
If ZnO is added so that SiO ₂ / ZnO = 45/55 (weight ratio) and this is provided as the transparent base material on the uppermost part on the light receiving surface side of the solar cell, inorganic UV cut transparency and protective film can be obtained. It is effective for improving the outdoor weather resistance of the cell. In addition,
This dense transparent silica film is also effective as a passivation film of a hygroscopic film such as polyimide or aramid, or a passivation film of oligomers discharged from polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) to the surface during heat annealing. It is.

[0105]

Embedded image

Further, additives such as a curing accelerator may be added as required. For example, when a hot melt material is laminated on a member to be laminated, an organosilane compound represented by a structure such as RSi (OR) ₃ (R: C ₂ H ₅ ) is used as a foam inhibitor and a defoamer for the buffer adhesive layer. It is also effective to add 6 parts by weight or less in the above mixing ratio. This is heated,
In the pressurizing step, it reacts with the above-mentioned organic peroxide (generates free radicals), becomes a cross-linking agent for the main component ethylene acetic acid copolymer, and is taken into the buffer adhesive layer. In addition, when the hot melt material is stored after being stacked or rolled, it has a function of preventing adhesion between the buffer adhesive layer and the back surface of the base material and facilitating peeling.

The thickness of the buffer adhesive layer may be appropriately adjusted to an optimum thickness depending on the organic peroxide to be used, the use environment, the member to be laminated, etc., and is not particularly limited, but is preferably 3 to 500 μm. More preferably, 3 to 50 μm,
Particularly, the range of 10 to 40 μm is preferable. If the thickness of the buffer adhesive layer is less than 3 μm, it is difficult to obtain a buffering effect, and if the thickness exceeds 500 μm, the light transmittance is reduced, and burrs are easily generated at the time of punching or the like. However, since the adhesive layer has a much higher transmittance than the above-described base material, it can be used up to 10,000 μm when used under high illuminance such as outdoors. The dynamic elastic modulus of the buffer adhesive layer after thermocompression bonding is preferably 5 × 10 ⁹ dyn / cm ² or less at 20 ° C.
1 × 10 ⁶ dyn / cm ² or more at 100 ° C., especially 1 × 10 dyn / cm ^{2 at} 20 ° C.
10 ⁹ -1 × 10 ⁶ dyn / cm ² , 2 × 10 ⁶ -1 at 100 ° C.
A range of × 10 ⁹ dyn / cm ² is preferable. In addition,
The maximum peak value of tan δ preferably appears at 20 ° C or lower, and particularly preferably appears in the range of -100 to + 15 ° C.

The buffer adhesive layer is usually provided only on one surface of the resin substrate, particularly when used as a laminate protective film. Further, when the material of the solar cell substrate and the material of the laminate film substrate are different from each other as described later, and a large difference occurs in the thermal shrinkage rate at the time of temperature rise, it is preferable to provide the solar cell substrate on both front and back sides to flatten the cell. The provision on both sides in this way is advantageous for outdoor use where the environment is severe. When provided on both surfaces of the resin substrate, the thickness of the resin substrate and the buffer adhesive layer is preferably reduced within the above range. Further, the buffer adhesive can be used alone as a sheet unit product having a thickness of 4 to 6 mm.

The means for providing the buffer adhesive layer on the resin substrate can be provided by a known method such as coating or extrusion coating. The thickness of the buffer adhesive layer and the entire resin substrate is preferably 10 to 600 μm, more preferably 10 μm.
１２０120 μm, furthermore 30-90 μm, especially 60-8
A range of 0 μm is preferred.

The hot melt material used in the present invention may be one in which a buffer adhesive layer is embossed or a grain is formed. This embossing or embossing
It is particularly preferably provided when the hot melt material of the present invention is laminated under pressure, and is preferably provided in a streak shape in the same direction as the transport direction during lamination. In addition, when used for bonding, the direction is arbitrary, but an optimum direction may be selected according to the bonding direction or the bonding object. By providing embossing or embossing, an escape path for air bubbles is formed, and mixing of air bubbles is reduced. In particular, when pressure lamination is performed by a roll laminator, when the laminate film is held by the roll of the roll laminator and nipples with the material to be laminated, air bubbles are likely to escape along the laminating direction. The size, interval (or density), etc. of the embossing or embossing are not particularly limited, but, for example, Ra = 0.4 to 10 μm,
The range is preferably 0.6 to 0.8 μm, the average interval between peaks 50 to 180 μm, and particularly preferably 60 to 140 μm. The means for providing the grain is not particularly limited, but it may be embossed or processed once into a release film and then transferred.

Next, a method for manufacturing a solar cell module will be described. An upper surface (light receiving surface) or a surface to be protected of a member to be laminated, such as a solar cell sheet, and a buffer adhesive layer on at least one surface of a resin substrate having a light transmitting property and heat resistance and a glass transition point Tg of 65 ° C. or more And a hot-melt film, preferably a buffer adhesive layer of the above-mentioned hot-melt material, and subjected to thermocompression bonding using a roll laminator or the like at a temperature of preferably 100 to 120 ° C. and a linear pressure of 20 to 70 g / cm. Here, the case of single-sided lamination will be described as an example, but double-sided lamination may be used depending on the member to be laminated or the use environment, in which case the buffer adhesive layer is sandwiched vertically toward the member to be laminated. Then, thermocompression bonding may be performed using a roll laminator or the like.

The obtained composite sheet is cut into a predetermined size and stored in a container equipped with a heating and pressurizing means such as an autoclave, preferably in dry air or in an atmosphere of N ₂ , especially N ₂ , more preferably. Direction perpendicular to the plane of the composite sheet,
In other words, 0.01 to 5.0 kg almost uniformly from the vertical direction,
In particular, a mechanical pressure of 0.1 to 5.0 kg is applied, and 70 ° C. or more, particularly 140 to 180 ° C. (pressure during heating 3 to 15 kg)
/ Cm ² ) by heating and pressurizing for 30 to 120 minutes to thermally crosslink and defoam, improve adhesion, and obtain the laminate of the present invention. In this case, the heating temperature by the heating and pressing means and the hydrostatic pressure can be arbitrarily adjusted depending on the member to be laminated or the hot melt material, and the timing of applying the mechanical pressure is also arbitrary, but the mechanical pressure is preferably after heating. It is preferable to keep the temperature until the temperature is cooled to room temperature. Particularly above the curing temperature of the adhesive layer, more preferably 70
１００100 ° C. and pressurized at 5-10 kg / cm ² ,
After defoaming by holding for 5 to 60 minutes, the temperature is equal to or higher than the curing temperature of the adhesive, more preferably 100 to 170 ° C, particularly 120 to 1
70 ° C., 3 to 15 kg / cm ² , especially 5 to 10 kg / cm ²
For 5 to 60 minutes, particularly 15 to 60 minutes, and heat-cured.

By laminating using a roll laminator in this way, the influence of irregularities on the member to be laminated, such as fine patterning of a comb-shaped electrode of a solar cell or the like, or fine pattern for separating and insulating cells, is obtained. It is hard to receive. In other words, when the structure surface on the member to be laminated and the buffer adhesive layer heated and increased in fluidity are sent while being nippled by the elastic roll of the roll laminator,
Bubbles that are likely to remain in the shadow of the pattern on the structure surface are efficiently pushed out by receiving a hydrodynamic force due to shear stress generated between the elastic rolls.

Further, the air bubbles which cannot be completely removed by the roll laminator are removed in a thermal crosslinking step by the heating and pressurizing means. At that time, preferably, a heat-resistant elastic member sheet is laminated on the upper surface (light receiving surface) of the composite sheet,
Further, a metal plate is further laminated thereon, and a plurality of the metal plates are laminated on the metal plate from above and below (stainless steel (SU)
S) It is preferable to apply pressure mechanically by a pressurizing means such as an air cylinder (via a flat plate having high rigidity such as a plate). As a result, the module, which has been arbitrarily deformed due to thermal shrinkage and internal stress of the various functional thin films laminated on the plastic substrate or the like, is laminated, and the device is corrected to be smooth and flat.

As described above, by applying a mechanical pressure as the above-mentioned laminated structure in the thermal crosslinking step by heating and pressing, α-Si, ITO,
It has the rigidity and thickness of a plurality of different components such as Al alloy, interlayer insulating film, sealing insulating protective film, etc., and by laminating and integrating them, the heat shrinkage rate at the final deposition of each layer, internal Random deformation of composite sheets having different stresses and the like can be easily corrected. Moreover, since a plurality of composite sheets are stacked, a large number of flattening corrections can be performed simultaneously, which is advantageous for mass production. In addition, even when compared with painting or the like, a product having extremely good surface flatness and smoothness and having excellent appearance can be obtained, and can be preferably used for high value-added products.

In addition, despite the fact that the base material, the laminated member and the like occupy most of the members that govern the thickness of the device in the integrated laminate, at least about 100 μm thick rigid metal such as SUS. Flatness and smoothness equivalent to using a glass substrate can be obtained. For this reason, it is possible to perform punching by a simple air press process as compared with a sheet body using such a metal substrate or a glass substrate, and it is also easy to perform through-hole processing with a YAG laser. Can be. Therefore, the productivity is much higher than the sheet body using the metal base or the glass base, and the thin film device can be precisely processed by simple means. Can contribute. In addition, by combining with patterning using a screen printing method, it is possible to quickly respond to a change in device design or the like, thereby reducing costs.

The heat-resistant elastic member sheet to be laminated is not particularly limited as long as it can withstand the above-mentioned heating temperature, and may be appropriately selected from known heat-resistant elastic members. As such an elastic member,
Examples thereof include heat-resistant silicone rubber, fluorine rubber (Viton), and fluorosilicone rubber. The thickness of the elastic member sheet is not particularly limited, but is usually in the range of 0.5 to 10 mm.

Examples of the metal plate to be laminated include aluminum, SUS, brass, steel plate, etc., but aluminum, which is particularly lightweight and has excellent heat conduction characteristics, is preferable. Although the thickness of the metal plate is not particularly limited, it is usually 0.1 mm.
It is in the range of 2-3 mm. These metal plates may be subjected to alumite processing or surface treatment such as plating, painting, or the like of chrome, nickel, nickel chrome, or the like by known means.

Further, in the solar cell module of the present invention,
In order to reduce the cost, a coating film having light resistance and weather resistance may be provided on the surface of the solar cell instead of the hot melt material. Such a resin coating film, although slightly inferior in terms of flatness, weather resistance, etc. as compared with those subjected to the hot lamination, can omit the laminating step and the flattening step, can be manufactured at low cost, and can be mass-produced. Is improved. In particular, it is suitable for a case where it is incorporated in a device or used mainly for indoor use.

[0120] Such a resin coating film has various properties such as transparency, toughness, adhesion to a transparent electrode, surface hardness, heat and cold resistance, low moisture absorption, and low gas barrier properties. Those having excellent characteristics and good balance are preferable. In particular, 2000 to 3000 (M
In order to maintain the mechanical strength of the coating film with a molecular weight of about n) or less, the main resin capable of exhibiting the above-mentioned various properties must be butylated at 200 ° C. or less, which is the heat-resistant temperature of the plastic base material. Melamine resin, methylated melamine resin (both Catalyst 6000: manufactured by Mitsui Chemicals: a small amount of a melamine curing catalyst, etc.), non-yellowing modified isocyanate compound, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI) and isocyanurates thereof Ring-containing trimers or the following blocked isocyanates (low-temperature-curable block isocyanates in which the isocyanate group of a non-yellow-modified isocyanate compound is blocked with an active methylene group of acetylacetone (Duranate “MF-K60X” (Asahi Kasei Corporation)
Thermosetting resin which undergoes a cross-linking reaction with a low-temperature-curable blocked isocyanate blocked with MEK (methyl ethyl ketone) oxime or the like) and polymerizes. The thermosetting resin has excellent transparency, and has little change with time and discoloration due to light deterioration.

For example, as a fluorine-based resin, ethylene trifluoride, ethylene tetrafluoride, and an H portion of an ethylene chain are
-OR (R is alkyl, etc.), -OH, -ORCOOH
(R is an alkylene or the like) and a copolymer of a vinyl monomer and a lumiflon resin (Asahi Glass), an aliphatic or alicyclic type polyester, a polyether prepolymer,
Polyurethane resin by condensation with non-yellowing modified isocyanate compound (for example, Nippon Polyurethane PTMG / Corone HX cured product), saturated polyester resin (copolymer of esters such as ethylene glycol, neopentyl glycol, phthalic acid and adipic acid: for example Toyobo Byron)
A cured product of the above non-yellowing isocyanate, melamine and the like, epoxy resin (for example, oiled shell epicoat: 1
009) or a phenoxy resin (UCC: PKHH) cured product with the above curing agent, a partially saponified acrylic polyol, or a phosphazene monomer having a polymerization reactive functional group, which is cured by the above-mentioned non-yellowing isocyanate ( Light emission: PPZ monomer) and the like.

The coating may be formed by coating, screen printing, spin coating, or the like.

As described above, the various protective coating films, the resin substrate of the hot melt material and the buffer adhesive layer may also serve as the blue colored layer as described above. Further, fine particles of silica (Aerosil # R972, etc.) are co-dispersed in an amount of about 7 wt% or less of the solid content of the coating resin so that the haze value and the diffusion transmittance do not exceed the above-mentioned range and the non-diffusibility is maintained. To further enhance the uniformity of the color tone between the part such as the line surrounding electrode and the photoelectric conversion part with slightly higher reflectance, and secure the blackness seen from the top black filter by the blue coloring layer with a trace amount of blue dispersion pigment. Is also effective.

A blue colored layer may be provided on the surface of the black colored layer (black filter) opposite to the light receiving surface, and a blue coating film is preferably provided so as to seal the light receiving surface on the cell side. . The black filter is provided with a colored coating layer such as a black pigment or dye on one surface of a general-purpose semi-transparent substrate such as polymethyl methacrylate resin (usually opposite to the light-receiving surface) to provide subtle optical characteristics such as light transmittance. In many cases, a blue colored layer is formed on the colored coating layer side (a position farther from the coating layer when viewed from the light receiving surface) by a printing method such as screen printing or pad printing or a coating method. A colorless layer may be provided as a lower layer of the blue colored layer when viewed from the surface.) At this time, in order to prevent dissolution by an ink solvent or the like, it is necessary to sufficiently crosslink with a thermosetting binder or the like to increase the solvent resistance. The blue colored layer provided on the black filter side has a thickness of 1 to 20 μm,
The blue coating film on the cell side preferably has a thickness of 2 to 30 μm. With such a configuration, the color tone of the translucent black optical property control layer and the blue coloring layer thereunder and the blue color of the solar cell blue surface sealing film located thereunder are superimposed, and when viewed from the light receiving surface side, A deeper blackness can be obtained, and for example, in the case of a black dial for a watch, an aesthetic advantage can be obtained.

The colorant such as a blue color pigment at this time is as described above. However, in a black dial clock and the like often used in outdoor use,
Blue fluorescent dye (for example, UV wavelength conversion dye, SDPK
Derivatives Nippon Soda Co., Ltd. 3-Amino-6-benzoyl amino-2,5-
2,2'- of dicyano pyrazin (the following structural formula) and lanthanide
Bipyridine, 1,10-Phenanthroline complex), luminous pigment (Blue Luminova, manufactured by Nemoto Special Chemical Co., Ltd.) and the like are also effective.

[0126]

Embedded image

Further, the total light transmittance 70-85%, the diffuse transmittance 50-65%, the haze 65
A non-diffusible blue colored layer may be provided thereon, and a black colored layer (black filter) may be provided as an uppermost layer via a transparent adhesive layer, if necessary. The blue coloring layer may be provided as a whole sealing film. The light diffusion layer may be a printing sealing film in which the ultrafine silica (Aerosil: primary particle average diameter of about 15 to 20 nm) described above is dispersed in a phenoxy transparent resin. 5 to 2 containing 5 to 10 wt% of Aerosil
A dispersion film having a thickness of 0 μm has a total light transmittance of 82 to 86%, a diffuse transmittance of 39 to 50%, and a haze of 46 to 60%.
In this case, the thickness is preferably 5 to 30 μm. Further, the light diffusion layer may be provided as a laminate protective film. In this case, polyethylene naphthalate containing fine particles (alumina or the like) (Theonex: manufactured by Teijin Limited: 75 μm thick, total light transmittance 84%, diffuse transmittance 19%, haze 23
%Met. ), Porous high molecular weight polyethylene (Sun Map: manufactured by Nitto Denko Corporation) and the like.
Its thickness is preferably from 50 to 200 μm. The transparent adhesive layer may be the same as the buffer adhesive layer described above, and preferably has a thickness of 5 to 30 μm. With such a configuration, the degree of blackness is increased, and the light diffusion layer slightly transmits light, particularly under high illuminance conditions, and serves as an antireflection film, thereby improving battery characteristics.

[0128]

The present invention will be specifically described below with reference to examples. <Example 1> [Creation method] As shown in FIG. 1, a lower electrode layer 2, an amorphous silicon layer 3 having a pn junction, a pin junction, etc., an insulating layer 4, an ITO transparent electrode layer 5 on a flexible substrate 1. The through-hole 10 and the groove 10a were formed by laser processing on the solar cell body on which was formed.

Then, as shown in FIG. 2, a first element isolation layer 6 is formed on the ITO transparent electrode 5 having the groove 10a formed thereon.
And a second element isolation layer 7 were formed, and a wiring electrode layer 8 was formed on the first element isolation layer 6 and the through hole 10 as shown in FIG.

Next, as shown in FIG.
A color insulating ink prepared from the following color insulating resin composition 1 was printed thereon to form an insulating colored film 11. In addition, the bottom extraction electrode 9 was obtained by printing the conductive carbon paste on the back surface of the through hole at the very end after the insulating sealing film was applied to the entire surface, and the cell was turned over.

Color close to the surface color of the solar cell photoelectric conversion unit
If the insulating resin composition 1 is the solar cell of FIG.
Insulating film (primary printing resin) 4, element isolation layers 6 and 7 (secondary printing resin) exposed on the surface of the solar cell, carbon paste of wiring electrode 8 (to suppress the electrode from becoming extremely black) Or the like was used after being applied over the surface. The details will be described below.

Color insulating resin composition 1 Phenoxy resin (manufactured by UCC: PKHH Mn = 15400) 16 parts by weight Cyclohexanone 17 parts by weight Isophorone 17 parts by weight High resistance carbon black (manufactured by Degussa: average particle diameter 25 nm) 2 parts by weight Part: rutile-titanium dioxide (manufactured by Ishihara Sangyo: average particle diameter: 270 nm) 20 parts by weight Bengala (manufactured by Toda Kogyo: average particle diameter: 300 nm, CI No. 77499) 15 parts by weight Aerosil (manufactured by Degussa: average particle diameter: 25 nm) 4 parts by weight Dispersant (oleic acid) 3 parts by weight Antifoaming agent (Toshiba Silicone: TSA-720) 1 part by weight Leveling agent (Shin-Etsu Silicone: KS-66) 1 part by weight

A phenoxy resin was completely dissolved in a mixed solvent (cyclohexanone / isophorone) to obtain carbon black,
It was dispersed for 48 hours by a zirconia ball mill together with titanium dioxide, red iron oxide, aerosil and a dispersant. Thereafter, an antifoam leveling agent was added and mixed for another 2 hours.

Next, the following thermal crosslinking reaction components were added,
The mixture was further mixed and dispersed for 20 minutes to obtain a resin composition for a color insulating film.

5 parts by weight of n-butylated melamine resin (manufactured by Mitsui Toatsu Chemicals: Uvan 21R) 0.03 part by weight of curing accelerator (manufactured by Mitsui Toatsu Chemicals: Catalyst 6000)

The obtained color insulating resin composition ink was
After the primary printing with a 150 mesh stainless screen as the insulating layer 4 shown in FIG. 1, it was thermally cured in a 160 ° C. oven for 10 minutes. Next, an ITO transparent electrode layer 5 was formed on this insulating film by Ar gas sputtering.
In this sputtering step, no damage was observed in the insulating film, and a uniform ITO transparent electrode layer 5 could be laminated. Also, the sputtering time is lengthened and the I-
A TO transparent electrode layer was formed to obtain a solar cell having a dark purple appearance. Through holes 10 and open grooves 10a were formed in the cell body by laser processing.

Next, the first and second element isolation layers 6 and 7 shown in FIG. 2 were also formed by the screen printing pattern of the color insulating resin composition ink. A color insulating ink was also printed on the wiring electrode 8 shown in FIG. 4 using a 150-mesh stainless screen, and was thermally cured in a 160 ° C. oven for 10 minutes. As described above, the color insulating resin composition ink is printed on the insulating layer 4, the element isolation layers 6, 7 by the patterning method by the screen printing method, and is used to suppress the extreme blackness of the wiring electrode 8 by the carbon paste. Flexible amorphous Si solar cell with uniform color with almost the same color as the surface of the photoelectric conversion layer by covering the entire surface layer of the solar cell except the photoelectric conversion part with color insulating ink by applying multiple coats etc. I got a cell.

Next, the light-receiving surface of the solar cell has good translucency, is excellent in environmental reliability, has excellent physical strength, and can be expected to reduce the manufacturing cost by simplifying the process.
According to the transparent surface protective film disclosed in JP-A-140147, a sealing film was formed by screen printing. Here, a small amount of blue pigment is added and dispersed to have the function of a blue coloring layer, and further, fine particle silicon oxide (Aerosil) is also added, and the “diffuse transmittance” within the scope of the present invention, the “haze value” If the black colored layer is located at the top of the light-receiving surface when the generated light is captured as a non-diffusive layer, when viewed from the light-receiving surface side,
The purpose of the present invention is to make the presence of the photoelectric conversion portion of the solar cell more inconspicuous and present a deeper black color.

The raw material composition of the “blue insulating non-diffusible surface protective film” is as follows. Phenoxy resin (manufactured by UCC: PKHH Mn = 15,400) 20 parts by weight Cyclohexanone 40 parts by weight Isophorone 30 parts by weight Aerosil (manufactured by Degussa: average particle diameter 25 nm) 6.5 parts by weight β-type copper phthalocyanine (manufactured by Dainichi Seika) 0 1 part by weight Dispersant (oleic acid) 3 parts by weight Antifoaming agent (TSA-720 made by Toshiba Silicone) 1 part by weight Leveling agent (KS-66 made by Toshiba Silicone) 1 part by weight

In the above raw materials, the phenoxy resin was completely dissolved in a mixed solvent of cyclohexanone / isophorone and dispersed with aerosil and copper phthalocyanine in a zirconia ball mill for 48 hours. Next, an antifoaming agent and a leveling agent were added, and the mixture was further mixed for 2 hours, and the following heat-crosslinkable reaction components were added.

5 parts by weight of n-butylated melamine resin (manufactured by Mitsui Chemicals, Inc .: Coban 21R, weight average molecular weight: about 7,000) 0.03 parts by weight of curing accelerator (manufactured by Mitsui Chemicals, Catalyst 6000)

These were further mixed and dispersed for 20 minutes to obtain a blue insulating resin composition. The whole was subjected to encapsulation printing on the upper side of the light receiving surface in FIG. 5 using a 150 mesh polyester screen. After printing, in a 160 ° C. oven
The composition was thermally cured for 1 minute to obtain a blue insulating transparent resin composition. The film thickness at that time was about 10 μm. By adding Aerosil, the above film is coated on a 10 μm thick optical grade transparent PET film (total light transmittance 90%, diffuse transmittance 2%, haze 2%) in the range of non-diffusive transmission film. As a result of examining the optical characteristics, the total light transmittance was 84.8.
%, Diffuse transmittance 44% and haze 52%.

As a result, the color difference between the photoelectric conversion portion of the ITO coherent reflection color having a slightly higher reflectance in dark red purple and the other portion is further reduced. The degree of blackness is deepened, and the inside of the solar cell (in this case, the resin plate has a total light transmittance of 33%, a diffuse transmittance of 10%,
The haze was 32%. ) A more uniform black appearance was exhibited. In addition, the function as a solar cell was sufficient, and it turned out that it works without trouble even when assembling a watch. In addition,
Total light transmittance, diffuse transmittance and haze are JISK 710
5.

The above-mentioned photovoltaic cell on which a black plate having a uniform color tone of the photoelectric conversion unit was installed was measured using a high-speed colorimetric spectrophotometer (CMS-35sp) manufactured by Murakami Color Research Laboratory Co., Ltd. The colorimetry of the "stimulus value""L ^* a ^* b ^* color system (indicating lightness / redness / blueness, respectively)" was performed.

The value obtained by calculating the surface color of the photoelectric conversion portion from the L ^* a ^* b ^* value and the reflection color difference value ΔE with respect to the natural light incident on the insulating resin layer formed above was 2.5. Was.

As the method for forming the “blue non-diffusing surface protective film”, the first layer was obtained by the same method except that only “copper phthalocyanine” was used in the above-mentioned blue insulating non-diffusing surface protective film composition. . The protective film over the entire surface was an almost transparent non-diffusible permeable film having a thickness of 5 μm. This melamine crosslinkable protective film had a total light transmittance of 85.2% and a diffuse transmittance of 3
9.3% and haze 46.1%.

Next, a second layer, which is the uppermost layer on the light receiving surface side, is formed thereon.
Of the blue insulating non-diffusing surface protective film composition, "Aerosi
The same method was used except for "l". This overall sealing protective film showed a slightly pale blue color, was a highly transparent, non-diffusive, and not very noticeable wavelength-selective film having a light transmittance of 85 to 90% at 400 to 700 nm and a thickness of 5 μm. . Both the haze and the diffuse transmittance were less than 2%. Total light transmittance is 84
% And high. By providing such a two-layer protective film, I
The difference between the photoelectric conversion part and other parts of the TO interference reflection color was further reduced, and the blackness was deepened by placing a 0.5 mm thick black resin plate, and the black uniformity of the solar cell surface was further increased. . In this way, the blue layer is at the top of the cell (light receiving section)
Is effective to visually deepen the blackness, and the total light transmittance of the black resin plate used is low (30%
Below), diffuse transmittance (5% or less), and haze (15% or less), the blackness is further increased by making the second layer 10 μm thick except for the first layer.

On the light receiving surface side of the solar cell, a transparent conductive film such as ITO or ZnO is provided on the light receiving portion side of the photoelectric conversion film and used as a collecting electrode. However, since the thickness of the transparent conductive film is substantially equal to the wavelength of visible light, "light reflected on the surface of the film" and "light reflected on the film and the underlayer (in this case, α-Si) or the SUS / Al interface" Cause interference. For example, when the interference color generated by the interference reflection of the ITO film shows a dark blue color, the non-diffusible blue film is not used and the transparent insulating resin protective film (about 10 μm thick) is provided as it is, as described above. When a translucent black resin plate is provided on the upper part, it is effective because it can match the color tone of a solar cell having a deep blackness. In addition, in providing this transparent insulating resin protective film, in order to soften strong reflection light like metallic luster shown by thin film interference reflection light, ultra-fine silica of about 5 to 10% by weight of the resin is used.
) Makes it easier to balance the color tone.

In the case of ITO, the refractive index is 1.95 and the α of the power generation film is
IT that minimizes absorption at the maximum value of the spectral sensitivity curve of -Si
The O film thickness is about 705 °. However, the interference reflection color tone is slightly brown, and the transmittance is slightly reduced in order to develop the black color tone. However, when the angle is 800 to 850 °, the darkness increases and the color becomes bluish.

However, since the color tone of the interference reflected light changes one after another with a very slight change in thickness, it is extremely strict to control the film thickness to always maintain the dark blue reflected light. If the thickness is 800mm, the color becomes darker, so if the ITO film thickness is strictly suppressed, the non-diffusion type blue filter can be omitted, and the black translucency can be passed through the resin plate from the light-receiving side to achieve a deep black color. It is thought that it can go.

<Example 2> A solar cell coated with a color insulating ink was obtained in the same manner as in Example 1.

Next, a lamination film having a transparent surface and a PEN film having excellent physical strength including environmental reliability as a base material and a buffering adhesive laminated thereon is laminated on the solar cell light receiving surface and sealed. Stop processing was performed.

That is, a PEN film (Tg: 113 ° C.) having a thickness of 50 μm was prepared as a flexible film substrate having a light-transmitting property and heat resistance. Also, an ethylene-vinyl acetate copolymer resin (EVA: a vinyl acetate content of about 15 to 50% by weight) is used as a buffer adhesive layer, and dicumyl peroxide is used as an organic peroxide.
7 parts by weight with respect to parts by weight of the curing agent were added with a small amount of an additive such as a curing accelerator, and this was applied to one surface of the resin film base material so as to have a thickness of 20 μm. A buffer adhesive layer was used.

After lamination, a flattening process was performed to a level that satisfies the watch component specifications, and a watch film solar cell (solar cell) was obtained.

A blue colored resin film (75 μm thick) and a black colored resin plate (500 μm thick) as a clock face were stacked in this order on the above film solar cell, and assembled into a solar watch.

The blue colored resin film and the black colored resin plate were produced as follows. Also, JIS K
The total light transmittance and diffuse transmittance according to 7105 were measured to determine the haze, and these values are also shown. In addition, for a blue colored resin film, 400 to 700 nm
Shows the light transmittance at.

1) Blue colored resin film i) Production method β-type copper phthalocyanine pigment (cyanine blue: Dainichi Seika Co., Ltd.) 0.3 parts by weight Phenoxy resin (YP-505: Toto Kasei Co., Ltd.) 85 parts by weight Oleic acid (dispersant: reagent grade) 1 part by weight Isophorone (solvent) 100 parts by weight Cyclohexanone (solvent) 100 parts by weight (The phenoxy resin was previously dissolved in the above mixed solvent (a mixture of isophorone and cyclohexanone in the above ratio). , 30 wt% lacquer.)

Oleic acid was put into a lacquer, the pigment was well wetted with the oleic acid, and then dispersed well by a three-roll mill. The obtained slurry was dispersed in a zirconia ball mill.
After the dispersion for 0 hour, 600 parts by weight of the mixed solvent was added, and the mixture was further dispersed for 8 hours. To the obtained ink, 15 parts by weight of n-butylated melamine resin (Uban 21R: Mitsui Chemicals, Inc.) Catalyst (Catalyst 6000, 0.01 parts by weight (Mitsui Chemicals, Inc.) were mixed, coated on a PET film having a thickness of 74 μm and having a high permeability and a low diffusion property by a screen printing method at a thickness of 20 μm, and cured by heating at 150 ° C.

Ii) Total light transmittance: 82.8% Diffuse transmittance: 7.0% Haze: 8.4% Light transmittance (400 to 700 nm) 85 to 90%

2) Black Colored Resin Plate i) Production Method A thin plate of 0.5 mm in thickness and having an optical grade specular glass cell cast method and having a predetermined color tone transmittance was obtained. If further optical property control is needed,
PMM with optional optical characteristics by means of silk screen printing, pad printing, etc. with the silk screen ink of the object
An A plate was prepared.

Iii) Total light transmittance: 32.6% Diffuse transmittance: 10.6% Haze: 32.5%

The solar watch thus produced was excellent in black color tone, had no problem in operation of a solar cell, and had no problem in function as a timepiece.

A black resin plate is provided on the light receiving portion as a dial,
Using the high-speed colorimetric spectrophotometer (CMS-35sp) manufactured by Murakami Color Research Laboratory Co., Ltd., the “tristimulus value” and “L ^* a” of the photovoltaic cells uniformized in the color tone of the photoelectric conversion unit are used.
^* b ^* color system (indicating lightness / redness / blueness, respectively) ".

From the L ^* a ^* b ^* value, the surface color of the photoelectric conversion portion and the reflection color difference value ΔE with respect to the natural light incident on the insulating resin layer formed above were 1.51. Was.

[0165]

According to the present invention, the light-receiving surface side of the solar cell module can be made to have a black color tone so as to be suitable for a black clock face and the like, and the solar cell module does not deteriorate in function. A battery module is obtained.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing one manufacturing process of a solar cell used in a solar cell module of the present invention.

FIG. 2 is a partial cross-sectional view showing one manufacturing process of a solar cell used in the solar cell module of the present invention.

FIG. 3 is a partial cross-sectional view showing one manufacturing process of a solar cell used in the solar cell module of the present invention.

FIG. 4 is a partial sectional view showing a solar cell used in the solar cell module of the present invention.

FIG. 5 is a plan view showing one configuration example of a circular solar cell.

[Explanation of symbols]

 Reference Signs List 1 substrate 2 lower electrode layer 3 silicon-containing layer 4 insulating layer (color insulating resin composition) 5 transparent electrode layer 6 element separating layer (color insulating resin composition) 7 element separating layer (color insulating resin composition) 8 wiring electrode 9 Lower extraction electrode 10 Through hole 10a Opening 11 Insulating colored film 21 Solar cell 22 Photoelectric conversion unit 23 Element separation unit 25, 26 Extraction electrode unit 27, 28, 29 Connection unit

Claims (28)

[Claims] 1. A solar cell module having silicon and having a photoelectric conversion unit for converting incident light incident from a light receiving surface into electricity, a portion located on the light receiving surface side of silicon of the photoelectric conversion unit. A solar cell module, wherein a black colored layer is provided on the substrate, and a blue colored layer is provided between the black colored layer and the silicon. 2. The non-diffusible layer in which the blue colored layer has a total visible light transmittance of 75 to 90%, a diffuse transmittance of 1.0 to 45% and a haze of 1.0 to 60%. 1 solar cell module. 3. The non-diffusing property of the blue colored layer having a total visible light transmittance of 80 to 90%, a diffuse transmittance of 1.0 to 9.0%, and a haze of 1.5 to 9.0%. The solar cell module according to claim 2, which is a layer. 4. The solar cell module according to claim 1, wherein the blue colored layer has a light transmittance of 70% or more in a wavelength range of 400 to 650 nm. 5. The solar cell module according to claim 1, wherein the blue colored layer has a light transmittance of 80% or more in a wavelength range of 400 to 700 nm. 6. The black colored layer has a total visible light transmittance of 25 to 40%, a diffuse transmittance of 0.5 to 26%, and a haze of 2.0 to 82%. 5. The solar cell module according to any one of 5. 7. The layer according to claim 6, wherein the black colored layer has a total visible light transmittance of 25 to 37%, a diffuse transmittance of 0.5 to 13%, and a haze of 2.0 to 35%. Solar cell module. 8. The solar cell module according to claim 1, wherein said blue colored layer is provided as a resin film or sheet. 9. The solar cell module according to claim 1, wherein said blue colored layer is a protective coating film provided on said photoelectric conversion unit. 10. The blue colored layer has a thickness of 5 to 100 μm.
m. The solar cell module according to any one of claims 1 to 9, wherein 11. The solar cell module according to claim 1, wherein said black colored layer is provided as a resin film or sheet. 12. The black colored layer having a thickness of 300 to 10
The solar cell module according to any one of claims 1 to 11, which has a thickness of 00 µm. 13. An insulating colored film is provided on a portion other than the black colored layer and the photoelectric conversion portion, and the insulating colored film reduces a color difference between the photoelectric conversion portion and a portion other than the photoelectric conversion portion. The solar cell module according to claim 1. 14. The solar cell module according to claim 13, wherein said insulating colored film is obtained by dispersing pigment particles and / or dye in a binder. 15. The solar cell module according to claim 14, wherein the insulating colored film doubles as a blue colored layer in which blue pigment particles and / or dye are dispersed in a binder. 16. The solar cell module according to claim 14, wherein the pigment particles dispersed in the insulating colored film include a white fine pigment. 17. The solar cell module according to claim 1, wherein the photoelectric conversion unit is a non-single-crystal silicon film. 18. The solar cell module according to claim 1, wherein the photoelectric conversion unit has a transparent conductive film. 19. Interference of the transparent conductive film caused by interference reflection of light reflected on the film surface of the transparent conductive film and light reflected at an interface between the film and a film other than the film included in the photoelectric conversion unit. 19. The solar cell module according to claim 18, wherein the transparent conductive film has a function of controlling a color tone performed by the blue coloring layer by utilizing a color. 20. The transparent conductive film has a refractive index of 1.9 or more.
20. The solar cell module according to claim 19, wherein the solar cell module has a thickness of 500 to 900 angstroms. 21. The solar cell module according to claim 18, further comprising, on said transparent conductive film, an insulating colored film for reducing a color difference between said photoelectric conversion part and a part other than said photoelectric conversion part. 22. The solar cell module according to claim 21, wherein the insulative colored film for reducing the color difference has a function of controlling a color tone performed by a blue colored layer. 23. A light-transmitting and heat-resistant protective coating film on the photoelectric conversion unit.
Any of the solar cell modules. 24. The solar cell module according to any one of claims 1 to 23, wherein the solar cell module has any one of a base material made of a resin having translucency and heat resistance, glass, and stainless steel. 25. A hot plate having a buffer adhesive layer containing a thermosetting resin or a thermoplastic resin on at least one surface of a base material made of a resin having translucency and heat resistance, glass, or stainless steel. The solar cell module according to claim 24, wherein a melt material is laminated. 26. The solar cell module according to claim 25, wherein said hot melt material is a blue colored layer. 27. The solar cell module according to claim 25, wherein the hot melt material is laminated on the light-transmitting and heat-resistant protective coating film. 28. The solar cell module according to claim 1, which is used for a timepiece.