JP2010109207A - Photovoltaic device and vehicle using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To overcome the problem that weight reduction is hard to contrive in photovoltaic devices in the prior art because a solar cell is formed on a glass substrate. <P>SOLUTION: In a photovoltaic device, there are formed a back electrode 10, a semiconductor optical active layer 11, a transparent surface electrode 7, and a current-collecting wiring layer 8 on an insulating film substrate 1. By using series connection regions W2 and W3 to form holes 2 and 9, a see-through structure is achieved. By this structure, the weight of the photovoltaic device 6 is reduced. Furthermore, no short circuit is caused between the back electrode 10 and the transparent surface electrode 7 in the region where the holes 2 and 9 are formed, so as to allow the photovoltaic device 6 to have a structure excellent in product quality. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a see-through photovoltaic device using a film material and an on-vehicle device in which the photovoltaic device is installed on a window glass.

  As an example of a conventional thin film solar cell, a structure shown in FIG. 5 is known. FIG. 5 is a cross-sectional view of a thin film solar cell.

As illustrated, a transparent electrode layer 42 is formed on the glass substrate 41. The transparent electrode layer 42 is made of, for example, tin oxide, and is processed into a strip shape by laser scribing. An amorphous photoelectric conversion unit layer 43 and a crystalline photoelectric conversion unit layer 44 are formed on the transparent electrode layer 42. Similarly, the amorphous photoelectric conversion unit layer 43 and the crystalline photoelectric conversion unit layer 44 are also processed into strips by laser scribing. Then, the back electrode layer 45 is formed by depositing a silver layer or the like. The back electrode layer 45 is also processed into a strip shape by laser scribing. The transparent electrode layer 42 and the back electrode layer 45 are electrically connected using the grooves 46 and 47 (see, for example, Patent Document 1).
JP 2001-308362 A (page 4-5, FIG. 2)

  In a conventional thin film solar cell, a transparent electrode layer 42, an amorphous photoelectric conversion unit layer 43, a crystalline photoelectric conversion unit layer 44, and a back electrode layer 45 are formed on a glass substrate 41. With this structure, the use of the glass plate 41 is excellent in light translucency, but there is a problem that it is difficult to reduce the weight. And when installing a thin film solar cell in window glass, such as a vehicle, glass will be bonded together to a window glass, and there exists a problem that it is difficult to reduce the total weight of a vehicle. In addition, when the impact is applied to the thin film solar cell, the glass substrate 41 is crushed and scattered, and there is a problem in safety.

  Moreover, in the conventional thin film solar cell, the division | segmentation groove | channels 48 and 49 which penetrate the amorphous photoelectric conversion unit layer 43, the crystalline photoelectric conversion unit layer 44, and the back surface electrode layer 45 are formed. The thin film solar cell has a structure in which the transparent electrode layer 42 and the back electrode layer 45 sandwich the upper and lower surfaces of the thin amorphous photoelectric conversion unit layer 43 and the crystalline photoelectric conversion unit layer 44. In order to obtain a see-through type thin film solar cell, it is necessary to form a plurality of holes (in order to increase the aperture ratio and improve the visibility) in the cell region at the center of the drawing. The transparent electrode layer 42 and the back electrode layer 45 may short-circuit due to burrs or dielectric breakdown due to static electricity when forming the holes. In this cell structure, since different potentials are applied to the transparent electrode layer 42 and the back electrode layer 45, there is a problem that the cell region does not function.

  The photovoltaic device of the present invention is made in view of the above circumstances, and covers the insulating film substrate, the back electrode layer formed on the insulating film substrate, and the back electrode layer. In a photovoltaic device having a semiconductor photoactive layer formed on the insulating film substrate and a translucent surface electrode layer formed on the semiconductor photoactive layer, the semiconductor photoactive layer and The translucent surface electrode layer is divided into a plurality of cell regions by a first slit, and the back electrode layer is divided into a plurality of back electrodes corresponding to the cell region by a second slit and adjacent to each other. The back electrode corresponding to the cell region extends to the other adjacent cell region, and the extended region of the back electrode intersects the translucent surface electrode layer of the other cell region. Series connection area And, holes through at least the insulating film substrate is characterized in that through said series connection region. Therefore, in the present invention, a see-through hole is formed using the series connection region, so that a photovoltaic device having excellent product quality can be realized.

  In this invention, an invalid area | region is arrange | positioned between the effective areas of a photovoltaic cell, and an effective area | region and an invalid area | region are arrange | positioned alternately on an insulating film substrate. And a through-hole is arrange | positioned in an invalid area | region and a see-through structure is implement | achieved.

  Moreover, in this invention, an insulating film board | substrate is used as a support substrate of a photovoltaic cell. With this structure, weight reduction and safety are improved as compared with the case of a glass substrate.

  Moreover, in this invention, the invalid area | region of a photovoltaic cell is a series connection area | region between photovoltaic cells, and is used as an area | region which arrange | positions the hole for see-through. With this structure, it is possible to prevent a short circuit between the electrodes of the adjacent solar cells in the series connection region.

  Moreover, in this invention, the total weight of a vehicle can be reduced because the photovoltaic cell using an insulating film board | substrate is installed in the window glass of a vehicle.

  Below, the photovoltaic apparatus which is the 1st Embodiment of this invention is demonstrated in detail with reference to FIGS. 1-3. FIG. 1A is a plan view for explaining an insulating film substrate used in the photovoltaic device of this embodiment. FIG. 1B is a cross-sectional view for explaining the AA line direction of the insulating film substrate shown in FIG. FIG. 2A is a plan view for explaining the photovoltaic device of this embodiment. FIG. 2B is a cross-sectional view for explaining an electrode structure constituting the photovoltaic device. FIG. 3A is a plan view for explaining individual solar cells constituting the photovoltaic device shown in FIG. FIG. 3B is a perspective view for explaining individual solar cells constituting the photovoltaic device shown in FIG.

  As shown in FIG. 1A, the insulating film substrate 1 is made of a film material having excellent heat resistance such as polyethylene naphthalate, polycarbonate, polyethylene terephthalate, polyvinyl propylal, polyimide and the like. In the insulating film substrate 1, for example, a plurality of holes 2 are formed at regular intervals in the Y-axis direction (the short side direction of the substrate 1). And the row | line | column which consists of the hole 2 of the paper surface Y-axis direction is formed in the paper surface X-axis direction (long-side direction of a board | substrate) at fixed intervals. The interval in the X-axis direction is determined according to the size of individual solar cells formed on the insulating film substrate 1. In addition, when an opaque material such as polyimide is used as the insulating film substrate 1, a see-through effect is obtained.

  Further, the diameter and the total number of the holes 2 are determined so that the total area of the holes 2 with respect to the area of the solar cells formed on the insulating film substrate 1, that is, the aperture ratio is 10.0%, for example. . The aperture ratio can be arbitrarily changed depending on the usage method, for example, a usage method that places importance on visibility or a usage method that places importance on high output as a photovoltaic device.

  As shown in FIG. 1B, the insulating film substrate 1 has a thickness of about 5 to 300 μm, and is used as a support substrate for forming solar cells. And the insulating film board | substrate 1 consists of a film raw material, and compared with the case of a glass substrate, the weight reduction and size reduction of a photovoltaic apparatus are implement | achieved. Further, the insulating film substrate 1 is not broken like a glass substrate, and safety is improved. Then, the lead terminals 3 and 4 are fixed to the insulating film substrate 1 at both ends in the X-axis direction of the paper with a conductive adhesive 5 such as an Ag paste. The lead terminals 3 and 4 are connected to the transparent surface electrode 7 (see FIG. 2B) and the back electrode 10 (see FIG. 2B) formed on the insulating film substrate 1, respectively.

  As shown in FIG. 2 (A), on the insulating film substrate 1, a back electrode 10 (see FIG. 2 (B)), a semiconductor photoactive layer 11 (see FIG. 2 (B)), a transparent surface electrode 7 and a collector. The electric wiring layer 8 is formed, and the photovoltaic device 6 is formed. Then, a plurality of holes 9 penetrating the back electrode 10, the semiconductor photoactive layer 11, and the transparent surface electrode 7 are formed, for example, at regular intervals in the Y-axis direction (the short side direction of the substrate). The rows of the plurality of holes 9 are also formed at regular intervals in the X-axis direction (the long side direction of the substrate). As described above, the holes 9 are continuously formed corresponding to the holes 2 (see FIG. 1A) of the insulating film substrate 1, and the see-through structure of the photovoltaic device 6 is realized. The holes 2 and 9 are evenly arranged on the entire surface of the insulating film substrate 1 and the semiconductor photoactive layer 11, so that the background over the photovoltaic device 6 is not biased and the visibility is high. Be improved. In addition, the current collection wiring layer 8 may be arrange | positioned in the position shown in the figure, and may not be arrange | positioned.

  As shown in FIG. 2B, the back electrode 10 is formed on the insulating film substrate 1. The film thickness of the back electrode 10 is, for example, 0.05 to 1.0 μm. And the back surface electrode 10 consists of metal films, such as tungsten, aluminum, titanium, nickel, copper. The back electrode 10 may be a combination of transparent electrodes made of indium tin oxide or the like.

  A semiconductor photoactive layer 11 is formed on the insulating film substrate 1 so as to cover the back electrode 10. The film thickness of the semiconductor photoactive layer 11 is, for example, 0.3 to 1.0 μm. The semiconductor photoactive layer 11 is formed using amorphous silicon, amorphous silicon carbide, amorphous silicon germanium, or the like, and the semiconductor photoactive layer 11 is formed with a PN junction or a PIN junction.

  A transparent surface electrode 7 is formed on the semiconductor photoactive layer 11. The film thickness of the transparent surface electrode 7 is, for example, 0.03 to 1.0 μm. The transparent surface electrode 7 is made of zinc oxide, indium tin oxide, tin oxide or the like. In addition, the transparent surface electrode 7 should just be a film | membrane excellent in translucency, and does not necessarily need to be colorless and transparent.

  The first slit 12 is formed so as to penetrate the semiconductor photoactive layer 11 and the transparent surface electrode 7 by, for example, laser scribing. As shown in FIG. 2A, for example, the first slits 12 extend in the Y-axis direction on the paper surface and are arranged at regular intervals in the X-axis direction on the paper surface, so that the semiconductor photoactive layer 11 and the transparent surface The electrode 7 is divided into strips. The semiconductor photoactive layer 11 and the transparent surface electrode 7 are divided by the first slit 12 as a plurality of solar cells in the X-axis direction on the paper surface.

  An insulating resin 13 is formed between the first slit 12 and the back electrode 10, and even when a conductive material is embedded in the first slit 12, the back electrode 10 and the transparent electrode are adjacent to each other in adjacent solar cells. A short circuit with the surface electrode 7 is prevented. The first slit 12 may be left in a spatial state, or an insulating resin or the like may be embedded in the first slit 12.

  The second slit 14 is formed so as to penetrate the back electrode 10 by, for example, laser scribing. As shown in FIG. 2A, for example, the second slits 14 extend in the Y-axis direction on the paper surface and are arranged at regular intervals in the X-axis direction on the paper surface, thereby dividing the back electrode 10 into strips. To do. And the some back surface electrode 10 divided | segmented respond | corresponds to the said photovoltaic cell, respectively, and becomes a structure which pinches | interposes a semiconductor photoactive layer with the transparent surface electrode 7 and the back surface electrode 10. FIG. On the other hand, a part of the separated back electrode extends to the adjacent solar battery cell and has a region facing a part of the transparent surface electrode 7 of the adjacent solar battery cell. In addition, although mentioned later for details, this opposing area | region becomes an area | region for the adjacent photovoltaic cell to connect in series.

  The second slit 14 is embedded with an insulating resin 15 formed on the second slit 14, and a short circuit between adjacent solar cells is prevented. The back electrode layer formed integrally on the insulating film substrate 1 is divided into individual back electrodes 10 by the second slits 14.

  The third slit 16 is formed so as to penetrate the semiconductor photoactive layer 11 by laser scribing, for example. As shown in FIG. 2A, for example, the third slits 16 extend in the Y-axis direction on the paper surface and are arranged at regular intervals in the X-axis direction on the paper surface. The third slit 16 is disposed on the conductive resin 17 formed on the back electrode 10. The third slit 16 is embedded with a material constituting the transparent surface electrode 7, and the transparent surface electrode 7 and the conductive resin 17 are electrically connected. As a result, the back surface electrode 10 and the transparent surface electrode 7 between adjacent solar cells are electrically connected, and a plurality of solar cells on the insulating film substrate 1 are connected in series. And the desired output of the photovoltaic apparatus 6 is implement | achieved by the number of the photovoltaic cells arrange | positioned on the insulating film board | substrate 1. FIG.

  The third slit 16 may be embedded by a conductive member, and the transparent surface electrode 7 and the conductive resin 17 may be electrically connected using the third slit 16. .

  With this structure, each solar cell (area combining the area W1 and the area W2) divided by the first slit 14 has an effective area (area W1) and an ineffective area (area W2). The effective area is an area where light energy such as sunlight is converted into photocurrent. On the other hand, the ineffective region is a region where light energy is not converted into photocurrent, and functions as a series connection region for adjacent solar cells to be connected in series. The region W3 is an ineffective region of the solar battery cell located next to the region W1, and hereinafter, the regions W2 and W3 are referred to as series connection regions. And although demonstrated using FIG. 3 (A) and (B), the serial connection area | regions W2 and W3 become an area | region in which the hole 9 is formed.

  As shown in FIG. 3A, the current collecting wiring layer 8 is made of, for example, a silver layer and is formed on the transparent surface electrode 7. The current collector wiring layer 8 is mainly composed of main wiring layers 18 and 19 extending in the Y-axis direction (short-side direction of the substrate) on the series connection regions W2 and W3, and from the main wiring layers 18 and 19 to the paper surface. And branch wiring layers 20 to 23 extending in the X-axis direction (long-side direction of the substrate). Since the current collection wiring layer 8 becomes a light shielding film from the material, the branch wiring layers 20-23 located on a photovoltaic cell become comb-tooth shape, and efficiently collect the photocurrent which generate | occur | produces in a photovoltaic cell. .

  As shown in FIG. 3 (B), in the series connection regions W2 and W3, the hole 2 penetrating the insulating film substrate 1 and the back electrode 10, the hole 9 penetrating the semiconductor photoactive layer 11 and the transparent surface electrode 7 are arranged. Is done. And after forming the back surface electrode 10, the semiconductor photoactive layer 11, the transparent surface electrode 7, and the current collection wiring layer 8 on the insulating film substrate 1, the holes 2 and 9 are formed in the insulating film substrate 1, The back electrode 10, the semiconductor photoactive layer 11, and the transparent surface electrode 7 are formed by opening them together. Therefore, since the holes 2 and 9 are punched from the front surface side to the back surface side by a single punching process, they are formed as continuous holes. The punching direction of the holes 2 and 9 may be from the back side to the front side.

  As described above, the series connection regions W2 and W3 are invalid regions arranged between effective regions of adjacent solar cells. Further, the series connection regions W2 and W3 are regions where the back surface electrode 10 and the transparent surface electrode 7 of adjacent solar cells are connected. With this structure, when the holes 2 and 9 are formed, there is no problem even when the back electrode 10 and the transparent surface electrode 7 are electrically connected by the generated burr due to the sharp blade of the punch. Similarly, since the solar cell is configured by sandwiching the upper and lower surfaces of the thin semiconductor photoactive layer 11 between the back electrode 10 and the transparent surface electrode 7, dielectric breakdown due to static electricity becomes a problem. However, in the series connection regions W2 and W3, there is no problem even when the back electrode 10 and the transparent surface electrode 7 are conducted due to dielectric breakdown.

  In addition, although the effective area which functions as a photovoltaic cell decreases and the output as the photovoltaic device 6 decreases due to the increase in the ineffective area, the area of the ineffective area is reduced due to the balance with the aperture ratio as the see-through structure. Any design change is possible.

  Although not shown, an insulating resin layer having excellent translucency may be formed as a protective resin layer on the transparent surface electrode 7 on which the current collecting wiring layer 8 is formed. And the said insulating resin embeds the inside of the holes 2 and 9 of the photovoltaic apparatus 6, and coat | covers on the 1st slit 12, and the permeation of the water | moisture content to a photovoltaic cell is prevented. When the photovoltaic device 6 itself is used in a state of being enclosed in a waterproof package, the insulating resin layer may or may not be formed.

  As described above, in the present embodiment, a case where a plurality of holes 2 are formed in the insulating film substrate 1 and a see-through structure is realized through the holes 2 is described. However, the present invention is not limited to this structure. . For example, as the insulating film substrate 1, a film having heat resistance and high translucency, for example, a transparent film may be used. In this case, it is possible to realize a see-through structure by etching only the film on the glass substrate as in the structure using the conventional glass substrate without forming a hole penetrating the insulating film substrate 1. it can.

  In the present embodiment, the case where the see-through structure is realized by forming the holes 2 and 9 in the photovoltaic device has been described. However, the present invention is not limited to this structure. For example, when the back electrode 10 is formed as a transparent electrode, the see-through structure may be realized by forming the hole 2 in at least the insulating film substrate 1.

  In the present embodiment, the holes 2 and 9 are formed by opening the insulating film substrate 1, the back electrode 10, the semiconductor photoactive layer 11, and the transparent surface electrode 7 together by punching, for example. However, the present invention is not limited to this case. For example, the holes 2 and 9 may be opened collectively by a laser. In this case, the machining accuracy is better than when the holes 2 and 9 are formed by punching, and the width of the series connection regions W2 and W3 can be reduced. And the area of the ineffective area which occupies on the insulating film board | substrate 1 is reduced, and size reduction of a photovoltaic apparatus is implement | achieved, without reducing the output of the photovoltaic apparatus 6. FIG.

  Moreover, although this Embodiment demonstrated the case where a photovoltaic cell was divided in the long side direction of the insulating film board | substrate 1, it does not limit to this case. For example, the case where a solar cell is divided in the long side direction of the insulating film substrate 1 or the case where the solar cell is divided in an oblique direction of the insulating film substrate 1 may be used. Even in these cases, a see-through structure is realized by arranging a series connection region between the effective regions of the solar battery cells and forming a hole in the series connection region. In addition, various modifications can be made without departing from the scope of the present invention.

  Next, a vehicle provided with the photovoltaic device according to the second embodiment of the present invention will be described in detail with reference to FIG. FIG. 4 is a perspective view for explaining a vehicle using the photovoltaic device of the present embodiment.

  As shown in the figure, the vehicle 31 is provided with a front window glass 32, side window glasses 33 and 34, a sunroof window glass 35, a rear window glass (not shown), and the like. The photovoltaic devices 6 described in the first embodiment are installed on the side window glasses 33 and 34, the sunroof window glass 35, and the like. With this structure, during sunny weather, the photovoltaic device 6 receives sunlight and generates in-vehicle power. On the other hand, the photovoltaic device 6 has a see-through structure, and the side window glass 33, 34, the sunroof window glass 35, etc., are daylighted into the vehicle, and the person inside the vehicle is visible through the photovoltaic device 6. Can also enjoy. The in-vehicle power can be directly used as various driving powers such as in-vehicle audio and in-vehicle lights. In addition, by storing the in-vehicle power in the battery, the stored in-vehicle power can be used even when sunlight cannot be obtained in rainy weather, and an energy saving effect can be obtained. In addition, regarding the side window glass 33, it shall be arrange | positioned in the location which does not become a problem by law.

  Further, by adjusting the aperture ratio of the photovoltaic device 6, it is difficult to see the inside from the outside of the vehicle, a light shielding effect and a heat insulating effect can be obtained, and a UV effect can also be obtained by selecting a material for the insulating film substrate. .

  Further, the photovoltaic device 6 is made of an insulating film substrate, so that the weight of the vehicle body can be reduced as compared with the case of a glass substrate. Further, when the window glass is broken due to an accident or the like, the glass fragments are prevented from being scattered and the safety of persons in the vehicle is improved.

  In the present embodiment, the case has been described in which the photovoltaic device 6 is installed in the vehicle window and used as in-vehicle power. However, the present invention is not limited to this case. For example, the photovoltaic device 6 of the present embodiment may be similarly installed in windows of trains, airplanes, houses, buildings, etc., and used as the respective electric power. And also in these cases, weight reduction can be implement | achieved compared with the case of a glass substrate by forming a photovoltaic cell on an insulating film substrate, and safety can also be improved. In addition, various modifications can be made without departing from the scope of the present invention.

It is (A) top view and (B) sectional drawing for demonstrating the insulating film board | substrate used for the photovoltaic apparatus in embodiment of this invention. It is (A) top view for demonstrating the photovoltaic apparatus in embodiment of this invention, (B) It is sectional drawing. It is (A) top view (B) sectional drawing for demonstrating the photovoltaic cell which comprises the photovoltaic apparatus in embodiment of this invention. It is a perspective view for demonstrating the vehicle carrying the photovoltaic apparatus in embodiment of this invention. It is sectional drawing for demonstrating the thin film solar cell in conventional embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulating film substrate 2 Hole 6 Photovoltaic device 7 Transparent surface electrode 8 Current collection wiring layer 9 Hole 10 Back surface electrode 11 Semiconductor photoactive layer 31 Vehicle

Claims (7)

An insulating film substrate, a back electrode layer formed on the insulating film substrate, a semiconductor photoactive layer formed on the insulating film substrate so as to cover the back electrode layer, and the semiconductor photoactive In a photovoltaic device having a translucent surface electrode layer formed on the layer,
The semiconductor photoactive layer and the translucent surface electrode layer are divided into a plurality of cell regions by a first slit, and the back electrode layer is formed into a plurality of back electrodes corresponding to the cell region by a second slit. Divided,
The back electrode corresponding to one of the adjacent cell regions extends to the other adjacent cell region, and the extended region of the back electrode and the translucent surface electrode layer of the other cell region And a series connection region intersecting,
The photovoltaic device according to claim 1, wherein at least a hole penetrating the insulating film substrate passes through the series connection region. The hole penetrates the back electrode, the semiconductor photoactive layer, and the translucent surface electrode located in the series connection region, and a plurality of the holes are arranged in the series connection region. Item 2. The photovoltaic device according to item 1. A third slit is formed in the semiconductor photoactive layer on the extended region of the back electrode, and the third slit is embedded with a conductive material, and the extended region of the back electrode and the other cell The photovoltaic device according to claim 2, wherein the photovoltaic device is electrically connected to the light-transmitting surface electrode layer in a region through the conductive material. 4. The light according to claim 2, wherein the first slit, the second slit, and the third slit are arranged at regular intervals in a longitudinal direction of the insulating film substrate. Electromotive force device. The photovoltaic device according to claim 4, wherein the hole is embedded with an insulating resin. The photovoltaic device according to claim 5, wherein the first slit is embedded with an insulating resin. A vehicle, wherein the photovoltaic device according to any one of claims 1 to 6 is installed on a window glass.

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