JP3920468B2 - Photovoltaic device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photovoltaic device that can be cut at a predetermined position after manufacturing.
[0002]
[Prior art]
Photovoltaic devices are factory produced in a size suitable for the application. However, in all applications, it may not be possible to use the shape as it is produced in the factory. In such a case, a thin photovoltaic device can be processed into a shape optimal for the application by cutting a part at a construction site after production in a factory. For example, a photovoltaic device installed in a building, such as a roof for a private house, can be conveniently constructed if a part of the photovoltaic device can be cut in accordance with the shape of the building.
[0003]
However, when the photovoltaic device is cut, the electrodes arranged opposite to each other at the cutting edge may short-circuit each other. This is because the photovoltaic device has a structure in which a semiconductor thin film photoactive layer thinner than 1/1000 m is sandwiched between the first electrode layer and the second electrode layer. For example, as shown in FIG. 1, when the photovoltaic device is cut by the blade 9, the cutting edge is curved in the cutting direction of the blade 9, as shown in FIG. 2, and the first electrode layer 2 and the second electrode are cut. The layer 3 may be short-circuited.
[0004]
A technique for solving this problem is described in Japanese Patent Laid-Open No. 4-355973. In the method described in this publication, the cut photovoltaic device is heat-treated or etched to prevent a short circuit. As shown in FIG. 2, the heat treatment corrects the cut edge of the photovoltaic device that has been cut and bent flat. Since the photovoltaic device to be heat-treated has the resin layers 10 laminated on both sides, the resin layer 10 is softened by heat treatment, for example, by heating to 50 to 100 ° C. for 60 minutes and then cooling. By repeating the expansion and the heat contraction, the curved portion can be corrected to be flat. By this treatment, the short circuit between the first electrode layer 2 and the second electrode layer 3 is eliminated.
[0005]
In the etching method, the cut and curved portion is removed over, for example, several hundred to several thousand μm. Remove the shorted part by bending to eliminate the short.
[0006]
[Problems to be solved by the invention]
The method for eliminating the short-circuit at the cut portion by the above method has a drawback that it cannot be easily processed. For example, it is very difficult to perform a special process for eliminating a short circuit after cutting at a construction site where a photovoltaic device is installed. This is because a heat treatment furnace is required for heat treatment, and an etching tank is required for etching. Furthermore, both heat treatment and etching require time and effort, so that there is a disadvantage that the treatment cannot be performed quickly. Furthermore, if the heat treatment and etching cannot be completed completely, there is a disadvantage that the short circuit at the cut portion cannot be solved reliably.
[0007]
The present invention has been developed for the purpose of solving such drawbacks. An important object of the present invention is to provide a photovoltaic device that can be disconnected without causing the photovoltaic device to be short-circuited, and that can eliminate the process of eliminating the short circuit after the disconnection.
[0008]
[Means for Solving the Problems]
In the photovoltaic device of the present invention, a first electrode layer 2 and a second electrode layer 3 are laminated on both surfaces of a semiconductor thin film photoactive layer 1 that generates power when irradiated with light. Electric power generated in the semiconductor thin film photoactive layer 1 is output from the first electrode layer 2 and the second electrode layer 3. Furthermore, in the photovoltaic device according to claim 1 of the present invention, the first electrode layer 2 and the second electrode layer 3 are arranged in the cut portion 6 so as not to face each other.
[0009]
In the photovoltaic device according to claim 2 of the present invention, the cut portions 6 are arranged linearly.
In the photovoltaic device according to claim 3 of the present invention, the cut portions 6 are provided in a plurality of rows.
In the photovoltaic device according to claim 4 of the present invention, the first electrode layer 2 and the second electrode layer 3 are provided intermittently at the cut portion 6 so as not to face each other.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. However, the examples shown below exemplify a photovoltaic device for embodying the technical idea of the present invention, and the present invention does not specify the photovoltaic device as follows.
[0011]
Further, in this specification, in order to facilitate understanding of the scope of claims, the numbers corresponding to the members shown in the examples are referred to as “the scope of claims” and “the means for solving the problems”. It is added to the member shown by. However, the members shown in the claims are not limited to the members in the embodiments.
[0012]
The photovoltaic device shown in the plan view of FIG. 3 and the cross-sectional views of FIGS. 4 to 6 has a first electrode layer 2 and a second electrode on both surfaces of a semiconductor thin film photoactive layer 1 that generates power when irradiated with light. The layer 3 is stacked, and the power generated in the semiconductor thin film photoactive layer 1 is output from the first electrode layer 2 and the second electrode layer 3.
[0013]
In the photovoltaic device shown in the figure, the first electrode layer 2, the semiconductor thin film photoactive layer 1, and the second electrode layer 3 are stacked and fixed on the surface of the substrate 4. The substrate 4 is a film having a thickness of about 10 to 2000 μm made of a heat-resistant resin such as polyimide having flexibility, a metal plate such as stainless steel, or a hard plastic plate having no flexibility.
[0014]
The first electrode layer 2 is a metal foil. The metal foil used for the first electrode layer 2 is a thin film made of aluminum, titanium, nickel, steel or the like having a thickness of about 0.1 to 1.0 μm. Alternatively, the first electrode layer 2 may be a metal film having a laminated structure of aluminum / titanium or a laminated structure of tungsten / aluminum / titanium from the substrate 4 side.
[0015]
The semiconductor thin film photoactive layer 1 is a thin film in which amorphous silicon, amorphous silicon carbide, amorphous silicon germanium, or the like is laminated on pn or pin. The film thickness of the semiconductor thin film photoactive layer 1 is about 0.1 to 1.0 μm.
[0016]
The second electrode layer 3 is a transparent conductive film. As the transparent conductive film used for the second electrode layer 3, zinc oxide (ZnO), indium tin oxide (ITO), tin oxide (SnO ₂ ), or the like can be used.
[0017]
Furthermore, the photovoltaic device can protect the surface by forming a film-like transparent protective resin film 5 on the entire surface of the second electrode layer 3 as indicated by a chain line in FIG. 5 of FIG. Further, the protective resin film 5 can be provided on the entire back surface of the substrate 4 to protect the back surface. For the protective resin film 5, polyethylene terephthalate (PET), a fluororesin material, or the like can be used. The protective resin film 5 is provided by laminating and adhering films having a thickness of about 25 to 1000 μm. The protective resin film 5 can be easily laminated and adhered as a film in which an adhesive layer made of a thermoplastic resin is deposited on one side. This film can be laminated and adhered to the surface of the substrate 4 and the second electrode layer 3 by passing between the heat rollers. The protective resin film 5 can be laminated and bonded by using a vacuum thermocompression bonding method in which pressure is applied in a vacuum while heating, instead of the laminating method using a heat roller. A thermoplastic plastic such as ethylene-vinyl acetate copolymer (EVA) or polyvinyl butyral (PVB) can be used as an adhesive layer for adhering the protective resin film 5.
[0018]
In the photovoltaic device shown in the figure, this portion is a cut portion 6 so that it can be cut at a position indicated by a two-dot chain line. The cut portion 6 is disposed so that the first electrode layer 2 and the second electrode layer 3 do not face each other so that the first electrode layer 2 and the second electrode layer 3 do not short-circuit when cut here. is doing.
[0019]
The photovoltaic device shown in the figure has a through-hole 7 in the first electrode layer 2 and the second electrode layer 3 along the straight cut portion 6, and the first electrode layer 2 and the second electrode layer. 3 are arranged so as not to face each other. The through-holes 7 in the first electrode layer 2 and the second electrode layer 3 are oblong rectangles in the longitudinal direction of the cut portion 6, and the width of the through-hole 7 in the second electrode layer 3 is set to the through-hole 7 in the first electrode layer 2. Than wider. Furthermore, as shown in FIG. 6, the through-hole 7 is provided in a shape that wraps both ends so that the first electrode layer 2 and the second electrode layer 3 do not face each other.
[0020]
The photovoltaic device shown in the above figures is provided with the cut portions 6 in one row. However, the photovoltaic device of the present invention can be provided with two rows of cut portions 6 as shown in FIG. 7, and can also be provided with three or more rows of cut portions (not shown). The photovoltaic device provided with the cutting portions in a plurality of rows has a feature that the cutting position is not specified in one place and can be cut into an optimum shape at a plurality of positions.
[0021]
Furthermore, although the photovoltaic device shown in the figure is provided with the linear cut portion 6, the cut portion may be curved.
[0022]
The first electrode layer 2 is laminated on the surface of the substrate 4 and then irradiated with a laser beam or etched to provide a through hole 7. The width of the through hole 7 is, for example, 1 to 20 mm, preferably about 1 to 10 mm, and more preferably 1 to 5 mm so that the through hole 7 can be accurately cut when being cut. When the width of the through hole 7 is narrowed, the substantial power generation area of the semiconductor thin film photoactive layer 1 can be increased. Further, when the width of the through hole 7 is widened, there is a feature that the cutting position can be changed somewhat.
[0023]
An insulating paste 8 is applied to the through hole 7 of the first electrode layer 2. As the insulating paste 8, a polyimide resin or a phenol-based binder containing fine powder of an inorganic material such as silica (particle size: about 1.5 to 7.0 μm) is used. The insulating paste 8 is patterned and applied by a screen printing method, and then baked at 250 to 300 ° C. to be attached.
[0024]
Similarly to the first electrode layer 2, the second electrode layer 3 is also irradiated with a laser beam or etched to open the through hole 7. Similarly to the first electrode layer 2, the through-hole 7 of the second electrode layer 3 is coated with the insulating paste 8 and the protective resin film 5 is laminated on the surface thereof.
[0025]
8 and 9 show a state where the photovoltaic device having the above structure is cut at the cut portion. 8 shows a cross section at the cut portion 6 of the photovoltaic device shown in FIG. 4, and FIG. 9 shows a cross section at the cut portion 6 of the photovoltaic device shown in FIG. As shown in these figures, the photovoltaic device is cut at the first electrode layer 2 or at the portion of the through-hole 7 of the second electrode layer 3, so that the first electrode layer 2 and the second electrode layer 3 can be cut without short-circuiting. Further, as shown in FIG. 6, the photovoltaic device is provided with the through holes 7 of the first electrode layer 2 and the second electrode layer 3 in a state in which both ends are wrapped with each other. It is possible to reliably prevent the first electrode layer 2 and the second electrode layer 3 from being short-circuited by including at least one of the through holes 7.
[0026]
The photovoltaic device shown in the above figure has a single power generation region. However, the photovoltaic device of the present invention has a plurality of power generation regions connected in series with each other or connected in parallel. It can also have.
[0027]
【The invention's effect】
The photovoltaic device of the present invention has an excellent feature that it can be cut without causing a short circuit. This is because the photovoltaic device of the present invention has the first electrode layer and the second electrode layer laminated on both sides of the semiconductor thin film photoactive layer so as not to face each other at the cut portion. It is. In the cut portion, the first electrode layer and the second electrode layer that are not opposed to each other can reliably prevent a short circuit in the cut portion without contacting even if the cut edge is curved.
[0028]
In addition, since the photovoltaic device of the present invention does not cause a short circuit in a disconnected state, it takes a lot of time and labor after cutting at a construction site as in the past, so that a special short circuit due to heat treatment or etching is eliminated. There is no need to process. That is, the photovoltaic device of the present invention is characterized in that it can be easily processed at the construction site by omitting the process of eliminating the short circuit after cutting, and the time required for the construction can be shortened and the cost can be reduced.
[Brief description of the drawings]
1 is a cross-sectional view of a conventional photovoltaic device. FIG. 2 is a cross-sectional view showing a state where the photovoltaic device shown in FIG. 1 is cut. FIG. 3 is a plan view of a photovoltaic device according to an embodiment of the present invention. 4 is a cross-sectional view taken along line AA of the photovoltaic device shown in FIG. 3. FIG. 5 is a cross-sectional view taken along line BB of the photovoltaic device shown in FIG. 3. FIG. 6 is a photovoltaic device shown in FIG. FIG. 7 is a plan view of a photovoltaic device according to another embodiment of the present invention. FIG. 8 is a sectional view showing a state in which the photovoltaic device shown in FIG. FIG. 9 is a cross-sectional view showing a state where the photovoltaic device shown in FIG. 5 is cut at a cut portion.
DESCRIPTION OF SYMBOLS 1 ... Semiconductor thin film photoactive layer 2 ... 1st electrode layer 3 ... 2nd electrode layer 4 ... Substrate 5 ... Protective resin film 6 ... Cutting part 7 ... Through-hole 8 ... Insulating paste 9 ... Blade 10 ... Resin layer

Claims (1)

A semiconductor thin film photoactive layer that generates power when irradiated with light; a first electrode layer laminated on one surface of the semiconductor thin film photoactive layer; and a first electrode layer laminated on the other surface of the semiconductor thin film photoactive layer. and a second electrode layer, the power generated in the semiconductor thin photoactive layer, in the photovoltaic device to be outputted from the second electrode layer and the first electrode layer,
Along the cut portion, through holes are alternately provided in the first electrode layer and the second electrode layer so that the first electrode layer and the second electrode layer are not opposed to each other by the through hole. A photovoltaic device characterized by being arranged.

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