JP2009283724A - Solar battery and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar battery wherein a photoelectric conversion layer is composed of a thin film, which can improve the electric conductivity of a light incident-side electrode without reducing light use efficiency. <P>SOLUTION: In the solar battery, a transparent electrode layer 4, the photoelectric conversion layer 5 for performing photoelectric conversion, and a rear-face electrode layer 6 are stacked in order on a translucent insulation substrate 1, and a plurality of rectangular unit solar battery cells 2, each having a first side formed longer than a second side, are formed so as to be connected to each other along a direction of the second side. In an area on the translucent insulation substrate 1 whereon the unit solar battery cells 2 are to be formed, metal electrode layers 3 are provided which have a triangular cross-section and extend in the direction of the second side and are formed at predetermined intervals in a direction of the first side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a solar cell in which a photoelectric conversion layer is formed of a thin film and a method for manufacturing the solar cell.

  In solar cells, a device for introducing more light into a semiconductor layer serving as a power generation layer has been devised. For example, in a solar cell composed of a photoelectric substrate made of a photoelectric material, an incident-side metal electrode attached to a part of the substrate light-receiving surface, and a back electrode, the incident-side metal electrode has an inclined surface or a curved surface with respect to incident light. And a structure in which at least a part of incident light is reflected to the light receiving surface of the photoelectric substrate to improve the light use efficiency has been proposed (for example, see Patent Document 1).

  In addition to this, in a thin film solar cell, a light-incident formed on a light-transmitting insulating substrate in order to introduce a light into the semiconductor layer by forming a semiconductor layer as a power generation layer on the light-transmitting insulating substrate. A transparent electrode is used for the side electrode. However, the transparent conductive thin film forming the transparent electrode has low conductivity, and when a long distance current flows in the transparent electrode, a decrease in energy conversion efficiency due to Joule loss cannot be ignored. Therefore, conventionally, a groove having a trapezoidal cross section is formed in a light-transmitting insulating substrate, and a conductive electrode or lead is embedded in the groove, and the light-transmitting insulating material in which the conductive electrode or lead is embedded. A thin film solar cell having a structure in which a transparent electrode, a semiconductor layer having a PIN junction, and a back electrode are formed on a substrate to increase the conductivity of the light incident side electrode has been proposed (for example, see Patent Document 2).

Japanese Utility Model Publication No. 62-74349 JP 58-14873 A

  However, in the technique described in Patent Document 1, since the incident-side metal electrode is exposed on the surface of the solar cell, it is affected by deformation or surface corrosion due to external force, and as a result, the reflection reaching the light receiving surface. There was a problem that light decreased. In addition, the shape of the incident-side metal electrode part is ideally a triangle having a smooth surface and a sharp apex angle in the cross-sectional shape. There is also a problem that it is difficult to form the side metal electrode.

  Further, in the technique described in Patent Document 2, the cross-sectional shape of the metal electrode embedded in the translucent insulating substrate is a trapezoidal shape with a tapered side wall, and most of the light incident on the metal electrode is Since the light is reflected on the upper side and is not introduced into the semiconductor layer as the power generation layer, there is a problem that the light use efficiency is lowered and the energy conversion efficiency of the thin film solar cell is lowered.

  The present invention has been made in view of the above, and in a solar cell in which a photoelectric conversion layer is formed of a thin film, the solar cell can increase the conductivity of the light incident side electrode without reducing the light use efficiency. And its manufacturing method.

  In order to achieve the above object, a solar cell according to the present invention includes a plurality of units in which a transparent electrode layer, a photoelectric conversion layer that performs photoelectric conversion, and a back electrode layer are sequentially stacked on a translucent insulating substrate. In the solar cell in which the solar cells are connected in series in a predetermined direction, the translucent insulating substrate has a V-groove in a region where the unit solar cell is formed, and the transparent electrode layer is formed in the V-groove. A metal electrode layer in contact with the electrode is embedded.

  According to the present invention, a metal electrode layer having a V-shaped cross section is embedded in a light-transmitting insulating substrate, and a unit solar cell including a transparent electrode layer, a photoelectric conversion layer, and a back electrode layer is formed thereon. Since the light incident on the metal electrode layer is also reflected by the inclined surface and introduced into the photoelectric conversion layer, the conductivity of the light incident side electrode can be increased without lowering the light utilization efficiency. In addition, since the photocurrent generated in the photoelectric conversion layer passes through the metal electrode layer from the transparent electrode layer, the Joule loss can be reduced as compared with the case where the conventional light incident side electrode is composed of the transparent electrode layer, The energy conversion efficiency of the thin film solar cell can be increased. Furthermore, since the metal electrode part is formed in the groove part in the translucent substrate, the metal electrode part is not exposed to the atmosphere, and there is an effect that the influence of deformation or surface corrosion due to external force or the like can be suppressed.

  Exemplary embodiments of a solar cell and a method for manufacturing the solar cell according to the present invention will be explained below in detail with reference to the accompanying drawings. Note that the present invention is not limited to these embodiments. Moreover, the cross-sectional views of the solar cells used in the following embodiments are schematic, and the relationship between the thickness and width of the layers, the ratio of the thicknesses of the layers, and the like are different from the actual ones.

Embodiment 1 FIG.
1 is a plan view showing an example of the configuration of Embodiment 1 of a solar cell according to the present invention, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. It is B sectional drawing. In FIG. 1, the left-right direction on the paper surface is defined as the X-axis direction, and the direction perpendicular to the X-axis in the paper surface is defined as the Y-axis.

  In this solar cell, a plurality of strip-shaped (rectangular) unit solar cells 2 are arranged on a translucent insulating substrate 1 with the long axis direction aligned with the Y-axis direction and a predetermined distance in the X-axis direction. It has an arranged structure. Moreover, the thin film photovoltaic module is comprised by connecting the unit photovoltaic cell 2 arranged in the X-axis direction in series.

The unit solar cell 2 has a configuration in which a transparent electrode layer 4, a photoelectric conversion layer 5, and a back electrode layer 6 are sequentially laminated on a translucent insulating substrate 1. Here, the transparent electrode layer 4 is composed of a transparent conductive oxide film such as ZnO, ITO (Indium Tin Oxide), SnO _2, or a film obtained by adding a metal material such as Al to these transparent conductive oxide films. The

The photoelectric conversion layer 5 has a PN junction or a PIN junction, and has a structure in which one or more thin film semiconductor layers that generate power by incident light are stacked. As the thin film semiconductor layer, hydrogenated amorphous silicon, microcrystalline silicon, amorphous silicon germanium, microcrystalline silicon germanium, amorphous silicon carbide, microcrystalline silicon carbide, or the like can be used. Furthermore, when the photoelectric conversion layer 5 is composed of a laminated film of a plurality of thin film semiconductor layers, conductivity is improved by doping a transparent conductive film such as ITO or ZnO or impurities between different thin film semiconductor layers. A silicon compound film such as SiO ₂ or SiN may be inserted as an intermediate layer.

  As the back electrode layer 6, it is desirable to use a material having high conductivity and high light reflectance, and a laminated film of silver and aluminum, or a metal such as gold, chromium, titanium, or nickel can be used.

  Since this solar cell has a structure in which the transparent electrode layer 4 and the back electrode layer 6 are connected between adjacent unit solar cells 2, in the unit solar cell 2, the formation position of the transparent electrode layer 4 and the photoelectric The formation positions of the conversion layer 5 and the back electrode layer 6 are shifted in the X direction. Specifically, referring to FIG. 2, the unit solar cell 2-1 has a photoelectric conversion layer on the transparent electrode layer 4-1 having a structure separated from the adjacent transparent electrode layer 4-2 by the groove 8. A laminate of 5-1 and the back electrode layer 6-1 is formed, and this laminate is adjacent to the transparent electrode layer 4-1 of the unit solar cell 2-1 to which it belongs and on the right side in the X-axis direction. It is formed so as to straddle part of the transparent electrode layer 4-2 of the unit solar battery cell 2-2. Moreover, in the position which overlaps with the transparent electrode layer 4-2 of the adjacent unit solar cell 2-2 of the photoelectric conversion layer 5-1, the transparent electrode layer 4-2 of the adjacent unit solar cell 2-2 and its own A connection groove 9 for connecting the back electrode layer 6-1 of the unit solar cell 2-1 to which it belongs is formed. And by embedding the same material as the conductive material for forming the back electrode layer 6-1 in the connection groove 9, the back electrode layer 6-1 of the unit solar cell 2-1 is adjacent to the unit solar cell 2 -2 transparent electrode layer 4-2.

  In the solar cell having such a structure, the first embodiment has a configuration in which the metal electrode layer 3 is formed at a predetermined position on the translucent insulating substrate 1 where the unit solar cell 2 is formed. . The metal electrode layer 3 has a length substantially equal to the length in the X-axis direction on which the photoelectric conversion layer 5 of each unit solar battery cell 2 is formed, and has a predetermined interval in the Y-axis direction. 1 is embedded in the V-groove 7 formed in 1. The cross section in the direction perpendicular to the X-axis direction has a V shape. As the metal electrode layer 3, a metal film having a high reflectance with respect to sunlight, such as Al, and higher conductivity than the transparent electrode layer can be used. In Embodiment 1, the transparent electrode layer 4 of each unit solar battery cell 2 and the metal electrode layer 3 embedded in the translucent insulating substrate 1 are combined to form a light incident side electrode.

  FIG. 4 is a partial cross-sectional view showing an example of a metal electrode having a V-shaped cross section. Here, the V-shaped cross section is defined as a cross section composed of two inclined surfaces whose angle α formed with respect to the main surface of the translucent insulating substrate 1 is larger than 45 degrees as shown in FIG. . The two slopes intersect each other at an acute angle, and the tip of the cross section has an acute angle. Since the metal electrode layer 3 having such a cross-sectional shape has a slope that is steeper than 45 degrees with respect to the light-transmitting insulating substrate 1, light incident perpendicularly from the light-transmitting insulating substrate 1 side is photoelectrically converted by this slope. It can reflect on the layer 5 side. Further, the V groove 7 may not be a groove having a strictly triangular cross section, may be a groove having a slightly curved slope, or may have a slightly rounded tip.

  The angle of sunlight incident on the solar cell varies depending on the position of the sun. FIG. 5 is a partial cross-sectional view showing a positional relationship between a metal electrode having a V-shaped cross section and the sun at the time of south and middle. This will be described in detail with reference to FIG. 5. When the solar cell is installed so as to face the sun 15a in the middle of the spring equinox day and in the autumn equinox day, Sunlight enters perpendicularly to the translucent insulating substrate 1. However, the south-middle altitude of the sun fluctuates depending on the season, the south-middle altitude of the sun 15b is the highest on the day of the summer solstice, and the south-middle altitude of the sun 15c is the lowest on the day of the winter solstice. It will be ± 23.4 degrees with respect to the south-middle altitude of the sun 15a on the day and autumn day. Therefore, in order to reflect the sunlight in the south-central time to the photoelectric conversion layer 5 regardless of the season, the angle formed by the slope of the V-shaped metal electrode layer 3 with respect to the main surface of the insulating translucent substrate 1 It is desirable that α be 56.7 degrees or more.

  Assuming that the metal electrode layer 3 has a V-shaped cross section with the incident surface side as the apex and extends in the X-axis direction, the incident light L is incident on the metal electrode layer 3. Can also be reflected on the surface of the V-shaped metal electrode layer 3 toward the photoelectric conversion layer 5. Further, light having energy equal to or greater than the band gap of the photoelectric conversion layer 5 and light that has passed through the photoelectric conversion layer 5 is reflected again by the back electrode layer 6 to the photoelectric conversion layer 5. In addition, since the ratio of the light which injects into the vertex of the metal electrode layer 3 is very small, compared with the case where the cross-sectional shape of the said patent document 2 forms a trapezoid, the fall of the light utilization efficiency of incident light is reduced. Can be prevented.

  Here, the operation by the solar cell of the first embodiment will be described. When light enters the photoelectric conversion layer 5, a photocurrent is generated and collected by the light incident side electrode and the back electrode layer 6. At this time, the photocurrent generated in the photoelectric conversion layer 5 is collected in the transparent electrode layer 4 and further embedded in the lower part of the metal electrode layer 3 with higher conductivity in the short side direction of the unit solar cell. It flows in the (X-axis direction) and flows to the back electrode layer 6 of the adjacent unit solar cell 2. Thus, by using the metal electrode layer 3 having a high conductivity for the light incident side electrode, the photocurrent passes through the metal electrode layer 3 having a higher conductivity than that of the transparent electrode layer 4. Compared to a conventional thin film solar cell having a current path, Joule loss in the light incident side electrode is reduced, and the energy conversion efficiency of the thin film solar cell can be increased.

FIG. 6 is a diagram schematically showing the relationship between the interval between the metal electrode layers embedded in the unit solar cell formation position and the length of the short side of the unit solar cell. As shown in FIG. 6, the interval between the metal electrode layers 3 embedded in the unit solar cell 2 (the distance between the adjacent sides between the adjacent metal electrode layers 3) is d, and the unit solar cell. When the length of the short side 2 (side parallel to the X-axis direction) is W, it is desirable to set the distance d between the metal electrode layers 3 so as to satisfy the relationship of the following formula (1).
d ≦ 2W (1)

  With this relationship, the current path until the current generated in the photoelectric conversion layer 5 flows through the transparent electrode layer 4 and reaches the metal electrode layer 3 is W or less at the longest. Since the longest current path in the unit solar battery cell 2 when the metal electrode layer 3 is not embedded is W, the metal electrode layer 3 is arranged as described above so that it is more conductive than the metal electrode layer 3. The current path in the transparent electrode layer 4 having a low rate can be shortened, and the generated Joule loss can be reduced.

  Further, in the conventional solar cell in which the light incident side electrode is only the transparent electrode layer 4, in order to reduce the Joule loss in the transparent electrode layer 4, the short side (side parallel to the X axis) of the unit solar cell 2 is used. It was necessary to limit the length of this to about 20 mm at the maximum. However, in combination with the metal electrode layer 3 as in the first embodiment, the limitation due to Joule loss is relaxed and the shape of the unit solar cell 2 can be made wider.

  Next, a method for manufacturing a solar cell having such a structure will be described. FIGS. 7-1 to 7-6 are partial cross-sectional views showing an example of a method for manufacturing a solar cell in the AA cross section of FIG. 1, and FIGS. 8-1 to 8-9 are FIGS. It is a partial cross section figure which shows an example of the manufacturing method of the solar cell in -B cross section.

  First, flat white glass is used here as the translucent insulating substrate 1 (FIGS. 7-1 and 8-1). On this translucent insulating substrate 1, V-shaped grooves 7 having a V-shaped cross section perpendicular to the Y-axis are formed in a band shape at intervals d in the Y-axis direction (FIGS. 7-2 and 8-2). However, the V-groove 7 is divided so as to have a length W in the X-axis direction. That is, a plurality of unit solar cell formation regions in which the V-grooves 7 having a length W in the X-axis direction are formed at intervals d in the Y-axis direction are arranged at predetermined intervals in the X-axis direction.

  9A to 9B are diagrams illustrating an example of a V-groove forming method. As shown in FIG. 9A, a stencil mask 11 having an opening 11a having a width W is disposed on a translucent insulating substrate 1, and the plasma is oscillated with the same width as the width W of the opening 11a. Dry etching is performed inside. Since the depth of the etching groove processed in the translucent insulating substrate 1 is substantially determined by the time exposed to the plasma, as shown in FIG. 9-2, a V-groove 7 having a base (width) of 2 W is formed. Is done. Furthermore, it is desirable to smooth the surface of the V groove 7 by performing light etching after the V groove 7 is formed. As another processing method of the V-groove 7, the V-groove 7 may be formed by using precision cutting using a V-shaped blade, or a softer material such as a polyimide film is used for translucent insulation. When used as the substrate 1, the V-groove 7 may be formed by an imprint method.

  Thereafter, the ink in which silver particles are diffused in the V groove 7 is printed and then baked to form the metal electrode layer 3 so as to fill the V groove 7 (FIGS. 7-3 and 8-3). In addition to silver, metals such as aluminum (Al), gold, chromium, nickel, and titanium may be used as the electrode material constituting the metal electrode layer 3. In addition, a metal film having a high light reflectance is formed only on the surface in the V-groove 7, and a conductive material having a low light reflectance such as solder is formed in the center of the V-groove 7 (the center of the metal electrode layer 3). It may be formed. Furthermore, as a method for forming the metal electrode layer 3, an electroless plating method or a method of directly injecting molten metal into the V groove 7 may be used. In addition, after forming the metal electrode layer 3, it is desirable to perform a process such as polishing in order to reduce the level difference between the translucent insulating substrate 1 and the metal electrode layer 3.

Next, a ZnO film to which Al is added as the transparent electrode layer 4 is formed on the translucent insulating substrate 1 on which the metal electrode layer 3 is formed by a sputtering method (FIGS. 7-4 and 8-4). As an electrode material constituting the transparent electrode layer 4, in addition to the ZnO film, a conductive oxide film of ITO or SnO ₂ or a film in which a metal such as Al is added to these conductive oxide films in order to improve conductivity is used. be able to. Further, another film formation method such as a CVD method may be used as the film formation method. Further, in this example, the transparent electrode layer 4 is formed after forming the metal electrode layer 3 on the translucent insulating substrate 1, but the metal electrode is formed after forming the transparent electrode layer 4 on the translucent insulating substrate 1. Layer 3 may be formed.

Thereafter, the transparent electrode layer 4 is cut at intervals W in the X-axis direction by a laser scribing method, and the transparent electrode layer 4 is separated into lengths used for each unit solar cell 2 (FIG. 8-5). Thereby, the transparent electrode layer 4 is separated by the groove 8 extending in the Y-axis direction. Next, a thin film semiconductor layer is deposited on the transparent electrode layer 4 by a CVD method to form a photoelectric conversion layer 5 (FIGS. 7-5 and 8-6). Note that as the thin film semiconductor layer, a hydrogenated amorphous silicon film, a microcrystalline silicon film, an amorphous silicon germanium film, a microcrystalline silicon germanium film, an amorphous silicon carbide, a microcrystalline silicon carbide film, or a stacked film thereof may be used. Good. Alternatively, the photoelectric conversion layer 5 may be formed by stacking a plurality of thin film semiconductor layers. In this case, a transparent conductive film such as ITO or ZnO, or a silicon compound film such as an SiO ₂ film or SiN film improved in conductivity by adding impurities may be inserted as an intermediate layer between different thin film semiconductor layers. .

  Next, the photoelectric conversion layer 5 is cut at intervals W in the X-axis direction by a laser scribing method, and the photoelectric conversion layer 5 is separated for each unit solar cell 2 (FIGS. 8-7). In this case, it isolate | separates so that the lower layer transparent electrode layer 4 may be exposed. As a result, the photoelectric conversion layer 5 is formed with a connection groove 9 that is used when the back electrode layer 6 and the transparent electrode layer 4 of the adjacent unit solar cell 2 are electrically connected.

  Thereafter, a back electrode layer 6 made of a laminated film of silver and Al is formed on the photoelectric conversion layer 5 in which the connection grooves 9 are formed by a sputtering method (FIGS. 7-6 and 8-8). At this time, the back electrode layer 6 is formed under the condition that the back electrode layer 6 fills the connection groove 9 formed in the photoelectric conversion layer 5. As the material for the back electrode layer 6, other metals such as gold, chromium, titanium, nickel may be used. Further, as a method for forming the back electrode layer 6, a CVD method, a coating method, or the like may be used.

  Then, by separating the back electrode layer 6 and the photoelectric conversion layer 5 by a predetermined length in the X-axis direction by a laser scribing method, a separation groove 10 that separates the adjacent unit solar cells 2 is formed. The solar battery cell 2 is formed (FIGS. 8-9). Thereby, a solar battery having a structure in which the transparent electrode layer 4 and the back electrode layer 6 are connected in series between the adjacent unit solar battery cells 2 is obtained.

  According to the first embodiment, a V-groove having an acute apex angle is formed on the light incident side in accordance with the formation region of the unit solar cell 2 of the translucent insulating substrate 1, and a metal electrode is formed in the V-groove. Since the unit solar cell 2 including the transparent electrode layer 4, the photoelectric conversion layer 5, and the back electrode layer 6 is formed on the layer 3, the light incident on the metal electrode layer 3 is a metal There is almost no light that is reflected by the surface of the electrode layer 3 to the photoelectric conversion layer 5 and is incident on the apex of the metal electrode layer 3. In addition, after the photocurrent generated by the photoelectric conversion layer 5 reaches the transparent electrode layer 4, the back surface of the adjacent unit solar cell 2 through the metal electrode layer 3 having higher conductivity than the transparent electrode layer 4. It flows to the electrode layer 6. As a result, the Joule loss in the light incident side electrode is reduced as compared with a thin film solar cell having a conventional structure in which the transparent electrode layer 4 serves as a current path, and the efficiency of the thin film solar cell is reduced without reducing the light use efficiency. It has the effect that energy conversion efficiency can be improved. Furthermore, by using the metal electrode layer 3 for the light incident side electrode, the conductivity can be increased, and the transparent electrode layer 4 serves as a current path for the length of the unit solar cells in the arrangement direction of the unit solar cells. Compared with the thin film solar cell of the conventional structure, it also has the effect that it can be lengthened. In addition, since the metal electrode layer 3 is embedded in the translucent insulating substrate 1, there is an effect that the metal electrode layer 3 is hardly affected by deformation or surface corrosion due to external force.

Embodiment 2. FIG.
10-1 to 10-5 are partial cross-sectional views illustrating another example of the method for manufacturing the solar cell in the AA cross section of FIG. Here, a method for forming a metal electrode layer is shown in the method for manufacturing a solar cell.

  Also in the second embodiment, white glass is used for the translucent insulating substrate 1 (FIG. 10-1). By the processing using the ultraviolet laser on the translucent insulating substrate 1, processed grooves 12 extending in the X-axis direction are formed at predetermined intervals in the Y-axis direction (FIG. 10-2). Unlike the case of the first embodiment, the processed groove 12 does not need to have a substantially triangular cross-sectional shape, and the surface may not be smooth. Here, the processing groove 12 is formed using a processing method using an ultraviolet laser, but the processing groove 12 is formed using a method such as mechanical cutting or processing using a photolithography technique and an etching technique (wet etching or dry etching). 12 may be formed.

  Next, a translucent resin 13 such as polyimide is injected into the processed groove 12 (FIG. 10-3). The translucent resin 13 is desirably a material having a value close to the refractive index of the translucent insulating substrate 1 (glass substrate). When a glass substrate is used as the translucent insulating substrate 1, a translucent resin such as polycarbonate may be used.

  Thereafter, a translucent resin formed on the translucent insulating substrate 1 with a mold 14 having a triangular cross section and having protrusions 14a extending in the X-axis direction formed at predetermined intervals in the Y-axis direction. The V-groove 7 whose cross-sectional shape is V-shaped is formed in the translucent resin 13 by an imprinting method that is pressed against the resin 13 (FIG. 10-4). Thus, the surface of the V-groove 7 formed in the translucent resin 13 is smooth, and the apex angle thereof is sharper. The V groove 7 is formed at a predetermined interval in the X axis direction so that the length of the V groove 7 in the X axis direction is equal to the length W of the unit solar battery cell 2 in the X axis direction. The

  Then, the metal electrode layer 3 is formed in the V groove 7 (FIG. 10-5). Thereafter, the solar cell is manufactured by the same processes as those described in the first embodiment after FIGS. 7-4 and FIG. 8-4, and the description thereof is omitted.

  According to the second embodiment, even when a hard glass material is used for the translucent insulating substrate 1, a groove having a substantially triangular cross-sectional shape can be easily processed. Further, since the surface of the cross section is smoother and the shape thereof can be a shape close to a sharper triangle, the light use efficiency can be improved.

  As mentioned above, the manufacturing method of the solar cell concerning this invention is useful when manufacturing the thin film solar cell by which a photoelectric converting layer is comprised with a thin film.

It is a top view which shows an example of a structure of Embodiment 1 of the solar cell by this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a partial sectional view showing an example of a metal electrode having a V-shaped cross section. It is a partial sectional view showing the positional relationship between the metal electrode having a V-shaped cross section and the sun in the middle of the south. It is a figure which shows typically the relationship between the space | interval of the metal electrode layer embedded at the formation position of a unit photovoltaic cell, and the length of the short side of a unit photovoltaic cell. It is a partial cross section figure which shows an example of the manufacturing method of the solar cell in the AA cross section of FIG. 1 (the 1). It is a partial cross section figure which shows an example of the manufacturing method of the solar cell in the AA cross section of FIG. 1 (the 2). FIG. 3 is a partial cross-sectional view showing an example of a method for manufacturing a solar cell in section AA in FIG. 1 (part 3). FIG. 4 is a partial cross-sectional view showing an example of a method for manufacturing a solar cell in section AA in FIG. 1 (No. 4). FIG. 5 is a partial cross-sectional view showing an example of a method for manufacturing a solar cell in section AA in FIG. 1 (No. 5). FIG. 6 is a partial cross-sectional view showing an example of a method for manufacturing a solar cell in section AA in FIG. 1 (No. 6). It is a partial cross section figure which shows an example of the manufacturing method of the solar cell in the BB cross section of FIG. 1 (the 1). It is a partial cross section figure which shows an example of the manufacturing method of the solar cell in the BB cross section of FIG. 1 (the 2). FIG. 3 is a partial cross-sectional view showing an example of a method for manufacturing a solar cell in the B-B cross section of FIG. 1 (part 3). FIG. 8 is a partial cross-sectional view showing an example of a method for manufacturing a solar cell in section BB in FIG. 1 (No. 4). FIG. 5 is a partial cross-sectional view showing an example of a method for manufacturing a solar cell in section BB in FIG. 1 (No. 5). FIG. 6 is a partial cross-sectional view showing an example of a method for manufacturing a solar cell in section BB in FIG. 1 (No. 6). FIG. 7 is a partial cross-sectional view showing an example of a method for manufacturing a solar cell in section BB in FIG. 1 (No. 7). FIG. 8 is a partial cross-sectional view showing an example of a method for manufacturing a solar cell in section BB in FIG. 1 (No. 8). It is a partial cross section figure which shows an example of the manufacturing method of the solar cell in the BB cross section of FIG. 1 (the 9). It is a figure which shows an example of the formation method of the V groove whose cross section is V shape (the 1). It is a figure which shows an example of the formation method of the V groove whose cross section is V shape (the 2). It is a partial cross section figure which shows the other example of the manufacturing method of the solar cell in the AA cross section of FIG. 1 (the 1). It is a partial cross section figure which shows the other example of the manufacturing method of the solar cell in the AA cross section of FIG. 1 (the 2). It is a partial cross section figure which shows the other example of the manufacturing method of the solar cell in the AA cross section of FIG. 1 (the 3). FIG. 10 is a partial cross-sectional view showing another example of the method for manufacturing a solar cell in section AA in FIG. 1 (No. 4). FIG. 9 is a partial cross-sectional view showing another example of the method for manufacturing a solar cell in section AA in FIG. 1 (No. 5).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Translucent insulated substrate 2 Unit solar cell 3 Metal electrode layer 4 Transparent electrode layer 5 Photoelectric conversion layer 6 Back surface electrode layer 7 V groove 8 Groove 9 Connection groove 10 Separation groove 11 Stencil mask 11a Opening part 12 Processing groove 13 Light transmission Resin 14 Mold 14a Protrusion 15a Sun in the middle of the middle
15b The sun in the middle of the middle (at the summer solstice)
15c The sun in the middle of the south (at the winter solstice)

Claims (7)

A solar cell in which a plurality of unit solar cells in which a transparent electrode layer, a photoelectric conversion layer that performs photoelectric conversion, and a back electrode layer are sequentially stacked on a translucent insulating substrate are connected in series in a predetermined direction. In batteries,
The translucent insulating substrate has a V-groove in a region where the unit solar cell is formed,
A solar cell, wherein a metal electrode layer in contact with the transparent electrode layer is embedded in the V-groove.   2. The solar cell according to claim 1, wherein the V-groove is a groove constituted by two inclined surfaces inclined at an angle larger than 56.7 degrees with respect to a main surface of the translucent insulating substrate. . The unit solar cell has a rectangular shape in which the first side is longer than the second side, and a plurality of the unit solar cells are connected in series along the direction of the second side on the translucent insulating substrate. And
2. The solar cell according to claim 1, wherein the metal electrode layer extends in a direction of the second side and is formed at a predetermined interval in the direction of the first side.   The peripheral part of the area | region in which the said metal electrode layer of the said translucent insulated substrate is formed is formed with the translucent resin close | similar to the refractive index of the said translucent insulated substrate. The solar cell as described in any one.   4. The solar cell according to claim 3, wherein an interval in the direction of the first side of the metal electrode layer is not more than twice a length of the second side of the unit solar cell. On the translucent insulating substrate, a groove forming step having a V-shaped cross section in a predetermined direction of a region where unit solar cells are to be formed later,
A metal electrode layer forming step of filling the groove with metal and forming a metal electrode layer;
Forming a unit solar cell including a transparent electrode layer, a photoelectric conversion layer, and a back electrode layer on a formation region of the unit solar cell on the metal electrode layer forming surface side of the translucent insulating substrate; ,
The manufacturing method of the solar cell characterized by including. In the groove forming step,
A first step of forming a groove on the translucent insulating substrate in a predetermined direction in a region where a unit solar cell is to be formed later;
A second step of filling the groove with a transparent resin having a refractive index close to that of the translucent insulating substrate;
The predetermined direction is applied to the transparent resin portion on the translucent insulating substrate using a mold that extends in a predetermined direction of the formation region of the solar cell and has a protrusion having a V-shaped cross section. A second step of forming a groove having a V-shaped cross section extending to
The manufacturing method of the solar cell of Claim 6 characterized by the above-mentioned.

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