JP2007141967A - Photovoltaic element, photovoltaic module, and method of manufacturing photovoltaic element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photovoltaic element capable of suppressing connection failures when mounting a connection electrode to a collector electrode while suppressing complication in manufacturing processes, a photovoltaic module, and to provide a method of manufacturing the photovoltaic element. <P>SOLUTION: A surface side collector electrode 5 composed of a bus bar electrode 5b and a finger electrode 5a is formed on the surface corresponding to a power-generating region 18 of a translucent conductive film 4 in the photovoltaic element 11. A protective layer 10 for protecting the surface is formed on the surface corresponding to the power-generating region 18 of the translucent conductive film 4. The protective layer 10 is formed so as to be spaced apart at a distance L without contacting with both side-face parts of the bus bar electrode 5b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a photovoltaic element, a photovoltaic module, and a method for manufacturing a photovoltaic element, and more particularly, to a photovoltaic element having a protective layer formed in a power generation region, a photovoltaic module, and a photovoltaic element. Regarding the method.

  Conventionally, a photovoltaic device capable of protecting the surface of the photoelectric conversion layer from scratches and humidity by forming a protective layer on the surface of the photoelectric conversion layer, and thereby suppressing deterioration of device characteristics, and the photovoltaic device Manufacturing methods are known. FIG. 10 is a cross-sectional view of a photovoltaic element according to a conventional example. FIG. 11 is a plan view of the photovoltaic element according to the conventional example shown in FIG. FIG. 12 is a cross-sectional view showing a state in which a plurality of photovoltaic elements according to the conventional example shown in FIG. 10 are connected. First, the structure of a photovoltaic device 100 according to a conventional example will be described with reference to FIGS.

  As shown in FIGS. 10 and 11, a photovoltaic device 100 according to a conventional example has a collector electrode 102 formed on the upper surface of a photoelectric conversion layer 101. As shown in FIG. 11, the collector electrode 102 includes a finger electrode portion 102a for collecting current generated by the photoelectric conversion layer 101, and a bus bar electrode portion 102b for further collecting current flowing through the finger electrode portion 102a. And is composed of. Further, a collector electrode (not shown) similar to the collector electrode 102 formed on the upper surface of the photoelectric conversion layer 101 is also formed on the lower surface of the photoelectric conversion layer 101.

  Further, in the photovoltaic element 100 according to the conventional example, as shown in FIG. 10, a protective layer 103 is formed on the upper surface (light incident surface side) of the photoelectric conversion layer 101. The protective layer 103 has a function of suppressing the surface of the photoelectric conversion layer 101 from being scratched and a function of blocking the surface of the photoelectric conversion layer 101 from coming into contact with the atmosphere. That is, the protective layer 103 suppresses deterioration of the element characteristics of the photoelectric conversion layer 101 due to scratches on the surface of the photoelectric conversion layer 101, and the constituent material of the photoelectric conversion layer 101 is ionized by humidity in the air. Thus, it has a function of suppressing deterioration of element characteristics. Further, in the region where the protective layer 103 is in contact with the side surface of the collector electrode 102, the thickness of the protective layer 103 is increased to the same thickness as the collector electrode 102 due to surface tension.

  Further, on the upper surface of the bus bar electrode portion 102b of the photovoltaic element 100, as shown in FIGS. 10 to 12, one end of a tab electrode 104 for electrically connecting adjacent photovoltaic elements 100 to each other is provided. It is connected. The other end of the tab electrode 104 is electrically connected to a bus bar electrode portion (not shown) of the collector electrode formed on the back side of the adjacent photovoltaic element 100.

  13 and 14 are cross-sectional views for explaining a method of forming a protective layer on the surface of the photovoltaic element according to the conventional example shown in FIG. Next, a method for forming the protective layer 103 on the top surface of the photoelectric conversion layer 101 will be described with reference to FIGS. 10 and 12 to 14.

  First, as shown in FIG. 13, a mask layer 105 is formed on the upper surface of the bus bar electrode portion 102 b of the photovoltaic element 100. Next, as illustrated in FIG. 14, a resin material constituting the protective layer 103 is coated on the surface of the photoelectric conversion layer 101 by spraying using the mask layer 105 as a mask. Thereafter, the mask layer 105 is removed. In this way, the photovoltaic element 100 according to the conventional example shown in FIG. 10 is formed.

  Subsequently, one end of the tab electrode 104 is connected to the upper surface of the bus bar electrode portion 102b, and the other end of the tab electrode 104 is connected to a bus bar electrode portion (not shown) on the back side of the adjacent photovoltaic element 100. To do. Thereby, a plurality of photovoltaic elements 100 according to the conventional example shown in FIG. 12 are connected. Thereafter, the plurality of connected photovoltaic elements 100 are filled with a filler (not shown) to be modularized.

  Further, conventionally, in order to suppress the internal bubbles from entering the protective layer, the photovoltaic element configured so that the thickness of the protective layer formed on the light receiving surface of the photovoltaic element does not become larger than the average thickness, and the photovoltaic element A manufacturing method is known (see, for example, Patent Document 1).

  FIG. 15 is a plan view of a photovoltaic element according to another conventional example described in Patent Document 1. In FIG. 16 is a cross-sectional view taken along line 300-300 in FIG. First, with reference to FIG. 15 and FIG. 16, the structure of the photovoltaic element 200 by another example of the prior art described in patent document 1 is demonstrated.

  As shown in FIG. 15, a photovoltaic element 200 according to another conventional example described in Patent Document 1 is provided at both end portions in the Y direction on the upper surface of the photovoltaic element plate 201 (photoelectric conversion layer). Insulating member 202 is provided. Moreover, as shown in FIG. 16, the mold release agent 202a is apply | coated to the side part by the side of the electric power generation area | region 203 of the insulating member 202. As shown in FIG. The release agent 202 a has a function of reducing the surface tension of the protective layer 207 that contacts the side surface of the insulating member 202. Further, as shown in FIG. 15, a plurality of current collecting electrodes 204 (finger electrodes) for collecting current generated by the photovoltaic element plate 201 extend in the Y direction on the upper surface of the power generation region 203. Is provided.

  Further, a conductive foil body 205 (bus bar electrode) is provided separately from the current collecting electrode 204 on the upper surface of the insulating member 202. The conductive foil body 205 is connected to the current collecting electrode 204 on the upper surface of the insulating member 202. Further, the conductive foil body 205 has a function of further collecting a current flowing through the current collecting electrode 204. Further, as shown in FIG. 16, conductive foil bodies 206 are respectively provided at both end portions of the lower surface of the photovoltaic element plate 201 which is a position facing the conductive foil body 205.

  Further, a protective layer 207 (see FIG. 16) for protecting the photovoltaic element plate 201 from scratches and humidity is formed on the upper surface (light incident surface side) of the power generation region 203 of the photovoltaic element plate 201. Has been. The protective layer 207 is in contact with the release agent 202 a provided on the side surface of the insulating member 202. Therefore, in the vicinity of the side surface portion of the insulating member 202, as shown in FIG. 16, the protective layer 207 is repelled by the release agent 202a, and the thickness of the protective layer 207 is smaller than the average thickness.

  Next, with reference to FIG. 15 and FIG. 16, a manufacturing method of the photovoltaic element 200 according to another example of the prior art described in Patent Document 1 will be described. First, a release agent 202a is applied to one side surface of the insulating member 202. Next, the insulating member 202 is affixed to both ends of the photovoltaic element plate 201 in the Y direction (see FIG. 15) so that the surface to which the release agent 202a is applied is on the power generation region 203 side. Next, a conductive adhesive is applied to the plurality of collector electrodes 204 made of copper wire, and is adhered to the upper surface of the power generation region 203 of the photovoltaic element plate 201 so as to extend in the Y direction. At that time, the current collecting electrode 204 is bonded so that the end of the current collecting electrode 204 is positioned on the upper surface of the insulating member 202. Thereafter, the conductive foil body (bus bar electrode) 205 is attached to the upper surface of the insulating member 202 to connect the conductive foil body (bus bar electrode) 205 to the current collecting electrode 204.

  Next, the conductive foil body 206 is affixed to the both side edge parts of the lower surface of the photovoltaic element plate 201 at a position facing the conductive foil body 205.

  Subsequently, the resin material constituting the protective layer 207 is coated on the power generation region 203 on the upper surface (light incident surface side) of the photovoltaic element plate 201 by spraying. In addition, in the structure of patent document 1, when attaching the tab electrode (not shown) for electrically connecting the adjacent photovoltaic element 200 on the upper surface of the conductive foil body 205, it is conductive foil. It is necessary to suppress the formation of the protective layer 207 on the upper surface of the body 205. In this case, it is considered that the mask layer 208 is formed on the upper surface of the conductive foil body 205 when coating the resin material. When the tab electrode is formed, the mask layer 208 is removed after the protective layer 207 is formed, and then the tab electrode is attached to the upper surface of the conductive foil body 205.

JP 2004-228333 A

  However, in the photovoltaic device 100 according to the conventional example shown in FIGS. 10 to 14, as described above, the thickness of the protective layer 103 is the region where the protective layer 103 is in contact with the side surface portion of the collector electrode 102. Since the thickness is about the same as the thickness of the (bus bar electrode portion 102b), the mask layer 105 and the bus bar electrode portion 102b formed on the upper surface of the bus bar electrode portion 102b of the collector electrode 102 when the protective layer 103 is formed. There is an inconvenience that the resin material constituting the protective layer 103 enters the gap in the boundary portion. For this reason, when the mask layer 105 is removed after the protective layer 103 is formed, the protective layer 103 is formed on a part of the upper surface of the bus bar electrode portion 102b. Therefore, the tab electrode 104 is formed on the upper surface of the bus bar electrode portion 102b. There is a problem that connection failure may occur in the tab electrode 104 when connecting the two.

  Further, in the photovoltaic device 200 according to another conventional example described in Patent Document 1 shown in FIGS. 15 and 16, the thickness of the protective layer 207 is a region where the protective layer 207 is in contact with the side surface portion of the insulating member 202. Does not become larger than the average thickness, so that the problem as in the photovoltaic element 100 according to the conventional example does not occur. On the other hand, Patent Document 1 has a disadvantage that it is necessary to apply a release agent 202a to the side surface of the insulating member 202 in order to make the thickness of the protective layer 207 smaller than the average thickness. For this reason, in the manufacturing process of the photovoltaic element 200, since the process of apply | coating the mold release agent 202a to the side part of the insulating member 202 is needed, there exists a problem that a manufacturing process becomes complicated.

  The present invention has been made in order to solve the above-described problems, and one object of the present invention is to connect a connection electrode to a collector electrode while suppressing a complicated manufacturing process. To provide a photovoltaic device, a photovoltaic module, and a method for manufacturing a photovoltaic device capable of suppressing defects.

Means for Solving the Problems and Effects of the Invention

  To achieve the above object, a photovoltaic device according to a first aspect of the present invention is formed on a power generation region including a photoelectric conversion layer, a collector electrode formed on one surface of the power generation region, and a power generation region. And at least a part of the protective layer is formed at a predetermined interval from the side surface without contacting the side surface of the collector electrode.

  In the photovoltaic element according to the first aspect, as described above, by forming at least a part of the protective layer at a predetermined interval from the side surface without contacting the side surface of the collector electrode, Unlike the case where the protective layer is in contact with the side surface portion of the collector electrode, the thickness of the protective layer near the side surface portion of the collector electrode can be suppressed from becoming larger than the average thickness due to surface tension. For this reason, since it can suppress that a protective layer is formed in the part to which the connection electrode of a collector electrode is attached resulting from the thickness of a protective layer becoming larger than average thickness, by formation of a protective layer Occurrence of poor connection can be suppressed. As a result, it is possible to suppress the occurrence of connection failure when the connection electrode is attached to the collector electrode. Further, by forming the protective layer at a predetermined interval from the side surface without contacting the side surface of the collector electrode, the thickness of the protective layer is averaged without applying a release agent to the side surface of the collector electrode. Since it can suppress becoming larger than thickness, the process of apply | coating a mold release agent can be skipped. For this reason, it can suppress that a manufacturing process becomes complicated. Therefore, in the photovoltaic device according to the first aspect, it is possible to suppress a connection failure when the connection electrode is attached to the collector electrode while suppressing a complicated manufacturing process.

  In the photovoltaic element according to the first aspect, preferably, the protective layer is formed at a predetermined interval from both side portions of the predetermined portion without contacting both side portions of the predetermined portion of the collector electrode. Yes. If comprised in this way, since it can suppress that the thickness of the protective layer near the side part of both the predetermined parts of a collector electrode becomes larger than average thickness, it protects in the part to which the connection electrode of a collector electrode is attached It is possible to more effectively suppress the formation of the layer. As a result, it is possible to more effectively suppress the occurrence of connection failure when the connection electrode is attached to the collector electrode.

  In the photovoltaic element according to the first aspect, preferably, the collector electrode includes a finger electrode portion for collecting current generated in the power generation region, and a bus bar electrode portion for further collecting current flowing through the finger electrode portion. The protective layer is formed at a predetermined distance from both side surfaces without contacting both side surfaces of the bus bar electrode portion. If comprised in this way, since it can suppress that the thickness of the protective layer of both the side part vicinity of a bus-bar electrode part becomes larger than average thickness, it is a protective layer in the part to which the connection electrode of a bus-bar electrode part is attached Can be more effectively suppressed. As a result, it is possible to more effectively suppress the occurrence of connection failure when the connection electrode is attached to the bus bar electrode portion.

  The photovoltaic device according to the first aspect preferably further includes a light-transmitting conductive film formed on the surface of the photoelectric conversion layer, and the protective layer and the collector electrode are on the surface of the light-transmitting conductive film. Is formed. If comprised in this way, while being able to protect the surface of a translucent electrically conductive film with a protective layer, the electric power generated by the photoelectric converting layer can be efficiently collected with the collector electrode to which a connection electrode is attached.

  A photovoltaic module according to a second aspect of the present invention is a photovoltaic module including the photovoltaic element according to the first aspect. If comprised in this way, the photovoltaic module which can suppress the connection defect at the time of attaching a connection electrode to a collector electrode can be obtained easily, suppressing a complicated manufacturing process.

  According to a third aspect of the present invention, there is provided a method for manufacturing a photovoltaic device comprising: a step of forming a power generation region including a photoelectric conversion layer; a step of forming a collecting electrode on the surface of the power generation region; and a surface of the power generation region. And a step of forming a protective layer so as not to come into contact with the side surface portion of the predetermined portion of the collector electrode and to be spaced from the side surface portion by a predetermined distance. In this third aspect, “so as not to contact the side portion” has a broad meaning including not only the case where it does not completely contact the side portion but also the case where it does not substantially contact the side portion.

  In the photovoltaic element manufacturing method according to the third aspect, as described above, the protective layer is formed on the surface of the power generation region at a predetermined interval from the side surface without contacting the side surface of the collector electrode. Later, by attaching a connection electrode on the upper surface of the collector electrode, the thickness of the protective layer near the side surface portion of the collector electrode is larger than the average thickness due to surface tension, unlike when the protective layer is in contact with the side surface portion of the collector electrode. Therefore, it is possible to suppress the formation of the protective layer in the portion where the connection electrode of the collector electrode is attached due to the thickness of the protective layer being larger than the average thickness. . For this reason, since generation | occurrence | production of the connection failure location by formation of a protective layer can be suppressed, generation | occurrence | production of the connection failure at the time of attaching a connection electrode to a collector electrode can be suppressed. Further, by forming the protective layer at a predetermined interval from the side surface without contacting the side surface of the predetermined portion of the collector electrode, the protective layer can be formed without applying a release agent to the side surface of the collector electrode. Since it can suppress that thickness becomes larger than average thickness, the process of apply | coating a mold release agent can be skipped. For this reason, it can suppress that a manufacturing process becomes complicated. Therefore, in the method for manufacturing a photovoltaic device according to the third aspect, it is possible to suppress a connection failure when the connection electrode is attached to the collector electrode while suppressing a complicated manufacturing process.

  In the method for manufacturing a photovoltaic device according to the third aspect, preferably, a step of forming a mask layer having an opening having a width larger than the width of the predetermined portion of the collector electrode on the surface of the predetermined portion of the collector electrode; Forming a protective layer on the surface of the power generation region using the mask layer as a mask. If comprised in this way, a protective layer can be easily formed in the surface of a photoelectric converting layer at predetermined intervals from the side part, without contacting the side part of the predetermined part of a collector electrode.

  Note that, in the photovoltaic element including the above-described translucent conductive film, the surface of the translucent conductive film may have an uneven shape. With this configuration, the coefficient of friction of the surface of the translucent conductive film can be increased. Therefore, when forming the protective layer, the side surface portion can be easily formed without contacting the side surface portion of the collector electrode. Can be formed at predetermined intervals.

  In the photovoltaic device, the photoelectric conversion layer includes a first semiconductor layer of the first conductivity type, a substantially intrinsic second semiconductor layer formed on one surface of the first semiconductor layer, and a second semiconductor layer. A second semiconductor layer of a second conductivity type formed on the surface of the semiconductor layer; a substantially intrinsic fourth semiconductor layer formed on the other surface of the first semiconductor layer; and a surface of the fourth semiconductor layer. And a fifth semiconductor layer of the first conductivity type formed in the above. By applying a structure in which a protective layer is formed at a predetermined distance from the side surface without contacting the side surface of the collector electrode, the manufacturing process is prevented from becoming complicated. However, connection failure when the connection electrode is attached to the collector electrode can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a plan view showing the structure of a photovoltaic device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line 400-400 in FIG. First, with reference to FIG. 1 and FIG. 2, the structure of the photovoltaic element 11 by one Embodiment of this invention is demonstrated.

  As shown in FIG. 2, the photovoltaic device 11 according to an embodiment of the present invention has an n-type single crystal having a thickness of about 140 μm to about 300 μm and having a texture structure (uneven shape) formed on the upper surface and the lower surface. A substantially intrinsic i-type amorphous silicon layer 2 having a thickness of about 5 nm to about 20 nm is formed on a silicon substrate 1. The n-type single crystal silicon substrate 1 has a function as a power generation layer (photoelectric conversion layer). The n-type single crystal silicon substrate 1 is an example of the “photoelectric conversion layer” and “first semiconductor layer” in the present invention, and the i-type amorphous silicon layer 2 is the “second semiconductor layer” in the present invention. It is an example. A p-type amorphous silicon layer 3 having a thickness of about 5 nm to about 20 nm is formed on the i-type amorphous silicon layer 2. The p-type amorphous silicon layer 3 is an example of the “third semiconductor layer” in the present invention.

  On the p-type amorphous silicon layer 3, a translucent conductive film 4 made of ITO (Indium Tin Oxide) having a thickness of about 30 nm to about 150 nm is formed. In addition, a surface-side collector electrode 5 made of silver (Ag) paste is formed in a predetermined region on the upper surface of the translucent conductive film 4. As shown in FIG. 1, the surface-side collector electrode 5 is collected by a plurality of finger electrode portions 5a formed to extend in parallel to each other in the Y direction at a predetermined interval in the X direction, and the finger electrode portions 5a. And the bus bar electrode portion 5b formed so as to extend in the X direction. The finger electrode portion 5a and the bus bar electrode portion 5b have a thickness of about 10 μm to about 100 μm. The bus bar electrode portion 5b has a width of about 0.5 mm to about 3 mm (for example, about 2 mm). In addition, the surface side (A side in FIG. 2) on which the surface side collector electrode 5 is formed is the light incident surface side of the photovoltaic element 11.

  Further, as shown in FIG. 2, a substantially intrinsic i-type amorphous silicon layer 6 having a thickness of about 5 nm to about 20 nm and a thickness of about 5 nm to about 5 nm are formed on the lower surface of the n-type single crystal silicon substrate 1. An n-type amorphous silicon layer 7 having a thickness of 20 nm is sequentially formed. The i-type amorphous silicon layer 6 is an example of the “fourth semiconductor layer” in the present invention, and the n-type amorphous silicon layer 7 is an example of the “fifth semiconductor layer” in the present invention. On the lower surface of the n-type amorphous silicon layer 7, a translucent conductive film 8 made of an ITO film having a thickness of about 30 nm to about 150 nm is formed. Further, on the lower surface of the translucent conductive film 8, a back side collector electrode 9 similar to the front side collector electrode 5 is formed. The front-side collector electrode 5 and the back-side collector electrode 9 are examples of the “collector electrode” in the present invention.

  Further, as shown in FIG. 2, a protective layer 10 made of an acrylic resin to which silicon oxide is added as an additive is formed on the surface corresponding to the power generation region 18 of the translucent conductive film 4 on the light incident surface side. Has been. The protective layer 10 has a function of suppressing the surface of the translucent conductive film 4 from being scratched and a function of blocking the surface of the translucent conductive film 4 from coming into contact with the atmosphere. . That is, the protective layer 10 is formed on the surface of the element on the power generation region 13 and suppresses deterioration of the element characteristics of the photovoltaic element 11 due to scratches on the surface of the light-transmitting conductive film 4. The power generation region 13 of the photovoltaic element 11 is damaged by the humidity inside, and thus has a function of suppressing deterioration of element characteristics. The power generation region 18 refers to a planar region where power can be generated by the n-type single crystal silicon substrate 1 as a photoelectric conversion layer.

  Here, in this embodiment, as shown in FIG. 2, the protective layer 10 is separated from the side surface portion of the bus bar electrode portion 5b by a distance L (about 2 mm) without contacting both side surface portions of the bus bar electrode portion 5b. Is formed. For this reason, a region where the protective layer 10 is not formed is formed in the vicinity of both side surfaces of the bus bar electrode portion 5b in the surface of the translucent conductive film 4. A protective layer 10 is formed in a region on the upper surface of the finger electrode portion 5a other than the vicinity of both side portions of the bus bar electrode portion 5b. In addition, an uneven shape is formed on the surface of the translucent conductive film 4 so as to reflect the texture structure (uneven shape) of the n-type single crystal silicon substrate 1.

  As shown in FIGS. 1 and 2, a tab electrode 12 made of a copper foil for electrically connecting a plurality of photovoltaic elements 11 is formed on the upper surface of the bus bar electrode portion 5 b of the front-side collector electrode 5. Are connected at one end. Further, on the lower surface of the bus bar electrode portion 5b of the back surface side collector electrode 9, as shown in FIGS. 2 and 3, it is connected to the bus bar electrode portion 5b of the front surface side collector electrode 5 of the adjacent photovoltaic element 11. The other end side of the tab electrode 12 is connected. The tab electrode 12 is an example of the “connection electrode” in the present invention.

  FIG. 3 is a cross-sectional view showing the structure of a photovoltaic module including the photovoltaic device according to the embodiment shown in FIG. Next, the structure of the photovoltaic module according to one embodiment will be described with reference to FIG. The photovoltaic module according to one embodiment includes a plurality of photovoltaic elements 11, and each of the plurality of photovoltaic elements 11 is connected to adjacent light via a tab electrode 12 bent in a step shape. It is connected to the electromotive force element 11. The photovoltaic element 11 connected via the tab electrode 12 is sealed with a filler 13 made of EVA (Ethylene Vinyl Acetate) resin. A surface protective material 14 made of white glass for surface protection is disposed on the upper surface (light incident surface side) of the filler 13 encapsulating the plurality of photovoltaic elements 11. A PET film 15 and an Al foil 16 are arranged in this order from the photovoltaic element 11 side on the lower surface of the filler 13 encapsulating the plurality of photovoltaic elements 11.

  In the present embodiment, as described above, at least a part of the protective layer 10 is formed at a distance L from the side surface portion without contacting both side surface portions of the bus bar electrode portion 5b of the surface side collector electrode 5. Thus, unlike the case where the protective layer 10 is in contact with the side surface portion of the bus bar electrode portion 5b, the thickness of the protective layer 10 in the vicinity of the side surface portion of the bus bar electrode portion 5b is suppressed from being larger than the average thickness due to surface tension. Can do. For this reason, it is suppressed that the protective layer 10 is formed in the part on the upper surface where the tab electrode 12 of the bus-bar electrode part 5b is attached resulting from the thickness of the protective layer 10 becoming larger than average thickness. Therefore, it is possible to suppress the occurrence of defective connection portions of the tab electrode 12 due to the formation of the protective layer 10. As a result, it is possible to suppress the occurrence of poor connection when the tab electrode 12 is attached to the bus bar electrode portion 5b.

  In the present embodiment, at least a part of the protective layer 10 is formed on the side surface portion of the bus bar electrode portion 5b by forming a distance L from the side surface portion without contacting both side surface portions of the bus bar electrode portion 5b. Since it can suppress that the thickness of the protective layer 10 becomes larger than average thickness, without applying a mold release agent, the process of apply | coating a mold release agent can be skipped. For this reason, it can suppress that a manufacturing process becomes complicated. Therefore, in this embodiment, it is possible to suppress a connection failure when the tab electrode 12 is connected to the bus bar electrode portion 5b while suppressing the manufacturing process from becoming complicated.

  In the present embodiment, the light-transmitting conductive film 4 is formed on the surface of the light-transmitting conductive film 4 by forming the protective layer 10 and the surface-side collector electrode 5 to which the tab electrode 12 is attached. The current generated by the photovoltaic element 11 can be efficiently collected by the surface-side collector electrode 5 to which the tab electrode 12 is attached.

  Moreover, in this embodiment, since the surface of the translucent conductive film 4 is configured to have an uneven shape, the friction coefficient of the surface of the translucent conductive film 4 can be increased, so that the protective layer 10 When forming the protective layer 10, it is possible to easily form the protective layer 10 at a distance L from the side surface portion without contacting the side surface portions of the bus bar electrode portion 5b.

  4-7 is a figure for demonstrating the manufacturing method of the photovoltaic device by one Embodiment shown in FIG. 1 and FIG. Next, a manufacturing process of the photovoltaic element 11 according to the above-described embodiment will be described with reference to FIGS.

  First, as shown in FIG. 4, on the upper surface of the n-type single crystal silicon substrate 1 having a thickness of about 140 μm to about 300 μm, an RF plasma CVD method is used to substantially have a thickness of about 5 nm to about 20 nm. An intrinsic i-type amorphous silicon layer 2 and a p-type amorphous silicon layer 3 having a thickness of about 5 nm to about 20 nm are sequentially formed. Next, a substantially intrinsic i-type amorphous silicon layer 6 having a thickness of about 5 nm to about 20 nm and a thickness of about 5 nm are formed on the lower surface of the n-type single crystal silicon substrate 1 using an RF plasma CVD method. An n-type amorphous silicon layer 7 having a thickness of about 20 nm is sequentially formed.

  Then, the transparent conductive films 4 and 8 having a thickness of about 30 nm to about 150 nm are formed on the surfaces of the p-type amorphous silicon layer 3 and the n-type amorphous silicon layer 7 by using magnetron sputtering. Form.

  Next, an Ag paste having a thickness of about 10 μm to about 100 μm is formed in each predetermined region on the upper surface of the translucent conductive film 4 and the lower surface of the translucent conductive film 8 by screen printing. Comb-shaped front-side collector electrode 5 and back-side collector electrode 9 are respectively formed. As shown in FIG. 1, the surface-side collector electrode 5 includes a plurality of finger electrode portions 5a extending in parallel to each other in the Y direction at predetermined intervals in the X direction, and currents collected by the finger electrode portions 5a. And a bus bar electrode portion 5b extending in the X direction. Further, the back-side collector electrode 9 is formed in the same manner as the front-side collector electrode 5.

  Next, as shown in FIGS. 5 and 6, a mask layer 17 made of polyester having a thickness of about 50 μm is formed on the upper surface of the bus bar electrode portion 5 b of the front-side collector electrode 5.

  Here, in this embodiment, the mask layer 17 is formed to have an opening width of about 6 mm, which is larger than the width (about 2 mm) of the bus bar electrode portion 5b.

  Next, as shown in FIG. 6, an acrylic resin to which silicon oxide is added as an additive is coated on the upper surface of the light-transmitting conductive film 4 on the light incident surface side of the photovoltaic element 11 by spraying. Thereby, the protective layer 10 is formed on the upper surface of the translucent conductive film 4, and the region where the protective layer 10 is not formed in the vicinity of both side portions of the bus bar electrode portion 5b by the mask by the mask layer 17. Is formed. For this reason, the protective layer 10 is formed on the surface corresponding to the power generation region 18 of the translucent conductive film 4 at a predetermined distance from the side surface portion without contacting both side surface portions of the bus bar electrode portion 5b. .

  Since the protective layer 10 is not cured immediately after the protective layer 10 is formed, as shown in FIG. 7, the protective layer 10 slightly expands on the side surface side of the bus bar electrode portion 5b, and then the protective layer 10 is cured. . The distance L between the protective layer 10 after the protective layer 10 is cured and the side surface portion of the bus bar electrode portion 5b is about 2 mm.

  Finally, by removing the mask layer 17 formed on the bus bar electrode portion 5b, the photovoltaic element 11 according to the present invention shown in FIG. 2 is formed.

  Next, with reference to FIG. 1 to FIG. 3, a method of modularizing by connecting a plurality of photovoltaic elements 11 formed as described above will be described. As shown in FIGS. 1-3, the one end side of the tab electrode 12 which consists of copper foil is connected to the bus-bar electrode part 5b of the surface side collector electrode 5 of the several photovoltaic element 11 formed as mentioned above. . And the other end side of the tab electrode 12 is connected to the bus-bar electrode part (not shown) of the back surface side collector electrode 9 of the photovoltaic element 11 which adjoins. In this way, a plurality of photovoltaic elements 11 are connected in series as shown in FIG.

  Next, on the surface protective material 14 made of white glass, an EVA sheet that will later become the filler 13, a plurality of photovoltaic elements 11 that are connected by the tab electrode 12, an EVA sheet that will later become the filler 13, and PET A film 15 and an Al foil 16 are sequentially laminated. Then, the photovoltaic module according to this embodiment shown in FIG. 3 is formed by performing a vacuum laminating process while heating.

  In the present embodiment, as described above, the step of forming the mask layer 17 having an opening having a width larger than the width of the bus bar electrode portion 5b on the upper surface of the bus bar electrode portion 5b of the surface side collector electrode 5, and the mask layer 17 And forming a protective layer 10 on the surface corresponding to the power generation region 18 of the light-transmitting conductive film 4 on the surface corresponding to the power generation region 18 of the light-transmitting conductive film 4, The protective layer 10 can be easily formed at a distance L from the side surface portion without being in contact with both side surface portions of the bus bar electrode portion 5b.

  The embodiments and examples disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments and examples but by the scope of claims for patent, and includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, an example in which a protective layer is formed on the surface of the photovoltaic element on the light incident surface side by coating an acrylic resin to which silicon oxide is added by spraying has been shown. However, the protective layer 21 may be formed on the light incident surface side surface of the photovoltaic element 20 by a screen printing method as in the first modification shown in FIG. In this case, when the protective layer 21 is formed, it is not necessary to form a mask layer on the upper surface of the bus bar electrode portion 5b, so that the manufacturing process can be further simplified. In addition to the screen printing method, various methods such as a dipping method and a roll coater method may be used as a method for forming the protective layer on the light incident surface side surface of the photovoltaic element.

  In the above embodiment, an example in which the protective layer is formed at a distance L from the side surface portion without contacting both side surface portions of the bus bar electrode portion is shown, but the present invention is not limited to this, and FIG. As in the second modification shown, the protective layer 31 may be formed so as to form the contact region 31a where the side surface portion of the bus bar electrode portion 5b and the protective layer 31 are in contact with each other at a predetermined interval.

  Moreover, in the said embodiment, a protective layer is on the surface corresponding to the electric power generation area | region of a translucent electrically conductive film at intervals of about 2 mm (distance L) from a side part, without contacting the side part of a bus-bar electrode part. However, the present invention is not limited to this, and the distance L between the protective layer and the side surface portion of the bus bar electrode portion is not 2 mm as long as the protective layer is formed without contacting the bus bar electrode portion. It may be an interval. The region where the protective layer is formed is preferably almost the entire surface of the power generation region in terms of the protective layer function of preventing damage to the element surface and suppressing contact with the atmosphere on the element surface.

  Moreover, in the said embodiment, although the example comprised so that it had an uneven | corrugated shape on the surface of the transparent conductive film of a photovoltaic device was shown, this invention is not limited to this, The surface of a transparent conductive film An uneven shape may not be provided.

  Moreover, in the said embodiment, although the example which formed the protective layer on the translucent conductive film of the light-incidence surface side of a photovoltaic element was shown, this invention is not limited to this, A translucent conductive film is shown. You may form on the surface corresponding to the electric power generation area | region by the side of the light-incidence surface of the photovoltaic element which is not provided.

  In the above embodiment, an example in which an n-type single crystal silicon substrate having a texture structure (uneven shape) is used on the upper surface and the lower surface is shown. However, the present invention is not limited to this, and the n-type single crystal substrate having no texture structure is used. A crystalline silicon substrate may be used.

  In the above embodiment, the i-type amorphous silicon layer and the p-type amorphous silicon layer and the i-type amorphous silicon layer between the n-type single crystal silicon substrate and the n-type amorphous silicon layer, respectively. Although an example using a photoelectric conversion layer including a silicon layer has been shown, the present invention is not limited to this, and a photoelectric conversion layer not including an i-type amorphous silicon layer may be used. The present invention is not limited to the above photovoltaic elements, but can be applied to various photovoltaic elements such as a single crystal type photovoltaic element and an amorphous type photovoltaic element, as well as photovoltaic elements other than silicon-based photovoltaic elements. It is applicable also to a power element.

  Moreover, in the said embodiment, although the protective layer showed the example comprised from the acrylic resin which added the silicon oxide as an additive, this invention is not limited to this, A protective layer is an acrylic resin, an epoxy resin. , Silicone resin, EVA, PVA (Poly Vinyl Alcohol: polyvinyl alcohol), PVB (Poly Vinyl Butyral), polysilazane, etc., any one kind or a mixture of two or more kinds may be used. You may make it comprise from what added silicon oxide, aluminum oxide, magnesium oxide, titanium oxide, zinc oxide, etc. as an additive at least 1 of these as a main component. Further, the additive may be a substance other than the above as long as it is a metal oxide that does not substantially absorb light having a wavelength that affects the photovoltaic element to absorb and generate power. The additive may be an organic compound.

  Moreover, although the example using the mask layer which consists of polyester was shown as said mask layer in the said embodiment, this invention is not limited to this, It masks so that a protective layer may not be formed on the upper surface of a bus-bar electrode part. Any mask layer made of a material other than polyester may be used.

  Moreover, in the said embodiment, although the example using the collector electrode comprised by two bus-bar electrode parts and several finger electrode parts was shown, this invention is not restricted to this, The bus-bar electrode which comprises a collector electrode One or three or more parts may be used. In addition, the collector electrode may have a configuration other than the above, such as a finger electrode portion formed of a wire.

  Moreover, in the said embodiment, while having the function which suppresses a damage | wound on the surface of a translucent conductive film, the protective layer which has a function which interrupts | blocks the surface of a translucent conductive film contacting with air | atmosphere. However, the present invention is not limited to this, and the protective layer on the photovoltaic element according to the present invention is not limited to the above functions. It may be a protective layer having the following functions.

It is the top view which showed the structure of the photovoltaic device by one Embodiment of this invention. FIG. 4 is a cross-sectional view taken along line 400-400 in FIG. 1. It is sectional drawing which showed the structure of the photovoltaic module containing the photovoltaic element by one Embodiment shown in FIG. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic device by one Embodiment shown in FIG. It is a top view for demonstrating the manufacturing method of the photovoltaic element by one Embodiment shown in FIG. FIG. 6 is a cross-sectional view taken along line 500-500 in FIG. 5. It is sectional drawing for demonstrating the manufacturing method of the photovoltaic device by one Embodiment shown in FIG. It is sectional drawing which shows the 1st modification of the photovoltaic element by one Embodiment shown in FIG. It is a top view which shows the 2nd modification of the photovoltaic element by one Embodiment shown in FIG. It is sectional drawing of the photovoltaic device by an example of the past. It is a top view of the photovoltaic device by an example of the prior art shown in FIG. It is sectional drawing which shows the state which connected the photovoltaic element by an example of the prior art shown in FIG. It is sectional drawing for demonstrating the method of forming a protective layer on the surface of the photovoltaic device by an example of the prior art shown in FIG. It is sectional drawing for demonstrating the method of forming a protective layer on the surface of the photovoltaic device by an example of the prior art shown in FIG. FIG. 12 is a plan view of a photovoltaic element according to another example of the prior art described in Patent Document 1. It is sectional drawing along the 300-300 line | wire of FIG.

Explanation of symbols

1 n-type single crystal silicon substrate (first semiconductor layer)
2 i-type amorphous silicon layer (second semiconductor layer)
3 p-type amorphous silicon layer (third semiconductor layer)
4, 8 Translucent conductive film 6 i-type amorphous silicon layer (fourth semiconductor layer)
7 n-type amorphous silicon layer (fifth semiconductor layer)
5 Surface side collector (collector)
5a Finger electrode part 5b Bus bar electrode part 9 Back side collector electrode (collector electrode)
10, 21, 31 Protective layer 11, 20, 30 Photovoltaic element 12 Tab electrode (connection electrode)
13 Filling Material 14 Surface Protection Material 15 PET Film 16 Al Foil 17 Mask Layer 18 Power Generation Area

Claims (7)

A power generation region including a photoelectric conversion layer;
A collector electrode formed on one surface of the power generation region;
A protective layer formed on the power generation region,
The photovoltaic device, wherein at least a part of the protective layer is formed at a predetermined interval from the side surface without contacting the side surface of the collector electrode.   2. The photovoltaic element according to claim 1, wherein the protective layer is formed at a predetermined interval from both side surfaces of the predetermined portion without contacting both side surfaces of the predetermined portion of the collector electrode. . The collector electrode includes a finger electrode part for collecting current generated in the power generation region, and a bus bar electrode part for further collecting current flowing through the finger electrode part,
3. The photovoltaic element according to claim 1, wherein the protective layer is formed at a predetermined distance from both side portions without contacting the both side portions of the bus bar electrode portion. A translucent conductive film formed on the surface of the photoelectric conversion layer;
The photovoltaic device according to any one of claims 1 to 3, wherein the protective layer and the collector electrode are formed on a surface of the translucent conductive film.   A photovoltaic module comprising the photovoltaic element according to claim 1. Forming a power generation region including a photoelectric conversion layer;
Forming a collecting electrode on the surface of the power generation region;
Forming a protective layer on the surface of the power generation region so as not to contact a side surface of a predetermined portion of the collector electrode and at a predetermined interval from the side surface. A method for manufacturing a power element. Forming a mask layer having an opening having a width larger than the width of the predetermined portion of the collector electrode on the surface of the predetermined portion of the collector electrode;
The method for manufacturing a photovoltaic device according to claim 6, further comprising: forming a protective layer on a surface of the power generation region using the mask layer as a mask.

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