Solar cell unit and method for manufacturing solar cell unit

Abstract

Provided are a solar cell unit capable of preventing short circuit at shingled connection and a manufacturing method thereof. In a solar cell unit (1) of one aspect of the present invention, a first semiconductor layer (20) of a conductive type different from that of a semiconductor substrate (10) has a main functional portion (21) and an isolation portion (22), the main functional portion has a first electrode pattern (40) laminated thereon, has a first base end portion (23) formed so as to extend over the entire length of a second direction at an end portion of the first direction side of the semiconductor substrate (10), and has a first collection portion (24) extending and protruding from the first base end portion (23) toward the other side of the first direction, the isolation portion is formed in a linear shape so as to extend over the entire length of the second direction at an end portion of the other side of the first direction of the semiconductor substrate (10), and does not have the first electrode pattern (40) laminated thereon, and a second semiconductor layer (30) of the same conductive type as the semiconductor substrate (10) has a second base end portion (31) contiguous to the first direction side of the isolation portion (22) and extending in the second direction, and has a plurality of second collection portions (32) extending and protruding from the second base end portion (31) toward the first direction side.

Description

TECHNICAL FIELD

[0001] The present application relates to a solar cell and a method for manufacturing a solar cell. BACKGROUND

[0002] A back contact type solar cell is known in which a pair of semiconductor layers having different conduction types are formed on a complementary region on the back surface side of a semiconductor substrate, and an electrode pattern is laminated on each semiconductor layer. In the back contact type solar cell, in order to reduce the moving distance of carriers, it is preferable to configure a structure in which band-shaped semiconductor films having different polarities are alternately arranged in a plan view, and the band-shaped semiconductor films having the same polarity are connected. If a module is formed by connecting a plurality of solar cells, a structure can be assumed in which each band-shaped semiconductor film is arranged to extend in a solar cell connection direction, a base end portion connecting an end portion of a band-shaped semiconductor of one conduction type is provided on one side in the solar cell connection direction, and a base end portion connecting an end portion of a band-shaped semiconductor of the other conduction type is provided on the other side in the solar cell connection direction, that is, the pair of semiconductor layers are formed in a comb shape, respectively, and are arranged so that the teeth engage each other (for example, refer to Patent Literature 1).

[0003] In Patent Literature 1, a manufacturing method is disclosed in which, in a semiconductor wafer, a cell structure (semiconductor layer and electrode) of a pair of solar cells is formed in a mirror image (line symmetry) with the connection portion of one semiconductor layer adjacent, and the semiconductor wafer is cut at the boundary of the cell structure, thereby obtaining two solar cells. In Patent Literature 1, two solar cells are formed by cutting an octagonal semiconductor wafer having a chamfered portion at the four corners in the center, as a result of which each solar cell has an asymmetric shape in which the corner portion on the side on which the base end portion of one semiconductor layer is formed is chamfered.

[0004] In a case where a solar cell module is formed using a plurality of solar cells, a plurality of solar cell strings each formed by arranging a plurality of solar cells in a row are generally arranged in a row. Since the shape of the solar cell in the solar cell module described in Patent Literature 1 is asymmetric, the orientation of the solar cell in the solar cell string can be easily confirmed. The orientation of the solar cell string is determined depending on the electrical connection, so in the solar cell module of Patent Literature 1, the orientation of every other row of solar cells is reversed. Therefore, if a plurality of solar cells are formed in the semiconductor wafer in such a manner that they are oriented in the same orientation, solar cells having the polarity of the semiconductor layer reversed can be obtained, so it is possible to unify the chamfered portions in the solar cell module to the same side.

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2018-163988 SUMMARY

[0006] In Patent Literature 1, a gap is formed between solar cell units, and as a structure for improving the output per unit area of a module, there is a case where a so-called shingling configuration is adopted in which the end portions of the solar cell units are overlapped in a constant direction. In this case, the electrode configuration of the end portion of the solar cell unit on the surface side is in abutment with the semiconductor substrate (light-receiving surface) of the solar cell unit on the back surface side. In the case where the polarity of the abutment portion of the electrode configuration of the solar cell unit on the surface side is equal to the polarity of the semiconductor substrate on the back surface side, there is a possibility that the solar cell unit will short-circuit. As described above, when a plurality of solar cell units are formed on a semiconductor wafer in such a manner that they are oriented in the same direction, due to errors in the cutting position, there is a possibility that a minute semiconductor layer having an undesirable polarity will be formed at the end portion of the solar cell unit. Therefore, if a plurality of solar cell units are formed on a semiconductor wafer in such a manner that they are oriented in the same direction, there is a risk that a short circuit will occur at the time of shingling connection. In view of this situation, an object of the present application is to provide a solar cell unit capable of preventing a short circuit at the time of shingling connection and a method for manufacturing the same.

[0007] A solar cell unit according to one aspect of the present application includes a semiconductor substrate having a first conductivity type; a first semiconductor layer and a second semiconductor layer formed on a back surface of the semiconductor substrate, the first semiconductor layer having a different conductivity type from the semiconductor substrate, and the second semiconductor layer having the same conductivity type as the semiconductor substrate; and a first electrode pattern and a second electrode pattern, the first electrode pattern being laminated to the first semiconductor layer, and the second electrode pattern being laminated to the second semiconductor layer, the first semiconductor layer having a main functional portion and an isolation portion, the main functional portion having a first base end portion and a plurality of first collecting portions, and the first electrode pattern being laminated thereto, the first base end portion being formed at an end portion on one side in a first direction of the semiconductor substrate so as to extend in a second direction intersecting the first direction, the plurality of first collecting portions extending and protruding from the first base end portion toward the other side in the first direction, and the isolation portion being formed in a linear shape at an end portion on the other side in the first direction of the semiconductor substrate so as to extend in the entire length of the second direction, and the first electrode pattern not being laminated thereto, the second semiconductor layer having a second base end portion and a plurality of second collecting portions, the second base end portion being adjacent to the one side in the first direction of the isolation portion and extending in the second direction, and the plurality of second collecting portions extending and protruding from the second base end portion toward the one side in the first direction.

[0008] In the solar battery cell, the average width of the first direction of the isolation portion can be less than the average width of the second direction of the first collecting portion, and the average width of the second direction of the first collecting portion can be less than the average width of the first direction of the first base end portion.

[0009] In the solar battery cell, the average width of the first direction of the isolation portion can be 2000 μm or less.

[0010] A solar battery cell manufacturing method according to an aspect includes: forming a plurality of unit structures on a back surface of a semiconductor wafer having a first conductive type, the plurality of unit structures each having a first semiconductor layer, a second semiconductor layer, a first electrode pattern, and a second electrode pattern, the first semiconductor layer having a different conductive type from the semiconductor wafer, the second semiconductor layer having the same conductive type as the semiconductor wafer, the first electrode pattern being laminated to the first semiconductor layer, and the second electrode pattern being laminated to the second semiconductor layer; and cutting the semiconductor wafer at boundaries of the unit structures, the plurality of unit structures being arranged in a first direction and formed in the same direction, the first semiconductor layer having a main functional portion and an isolation portion, the main functional portion having a first base end portion and a plurality of second collecting portions, and the first electrode pattern being laminated thereto, the first base end portion being formed at an end portion of the first direction of the unit structure on one side thereof to extend in a second direction intersecting the first direction, the plurality of second collecting portions extending and protruding from the first base end portion toward the other side of the first direction, and the isolation portion being formed in a linear shape at an end portion of the first direction of the unit structure on the other side thereof to extend in the second direction, and the first electrode pattern not being laminated thereto, the main functional portion and the isolation portion of the unit structure adjacent on the one side of the first direction being formed to be continuous in the forming of the unit structures, and the main functional portion and the isolation portion of the unit structure adjacent on the one side of the first direction being separated from each other in the cutting of the semiconductor wafer.

[0011] According to the present application, a solar battery cell capable of preventing short circuit at shingled connection can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a back surface view of a solar battery cell according to an embodiment of the present application.

[0013] Figure 2 is Figure 1 is an A-A line sectional view of the solar battery cell of

[0014] Figure 3 is a view showing Figure 1A flowchart of the sequence of the manufacturing method of the solar cell unit.

[0015] Figure 4 Figure 3 A cross-sectional view of the semiconductor wafer after the unit configuration forming step of the solar cell unit.

[0016] Figure 5 Figure 1 A cross-sectional view of the solar cell module of the solar cell unit. DETAILED DESCRIPTION

[0017] Hereinafter, each embodiment of the present application will be described with reference to the drawings. In addition, in each drawing, the same reference numerals are attached to the same or equivalent portions. In addition, there are cases where the illustration of components, reference numerals, and the like are omitted in order to simplify. In this case, reference is made to other drawings. In addition, the shape and size of each component in the drawings are adjusted for easy observation.

[0018] <Solar Cell Unit>

[0019] Figure 1 is a back surface view of the solar cell unit 1 according to one embodiment of the present application. Figure 2 is a cross-sectional view of the solar cell unit 1. The solar cell unit 1 includes a semiconductor substrate 10 having a first conductive type; a first semiconductor layer 20 and a second semiconductor layer 30 formed on the back surface (the surface on the side opposite to the light-receiving surface) of the semiconductor substrate 10, the first semiconductor layer 20 having a different conductive type from the semiconductor substrate 10, and the second semiconductor layer 30 having the same conductive type as the semiconductor substrate 10; and a first electrode pattern 40 and a second electrode pattern 50, the first electrode pattern 40 being laminated on the first semiconductor layer 20, and the second electrode pattern 50 being laminated on the second semiconductor layer 30.

[0020] The semiconductor substrate 10 can be formed of a crystalline silicon material such as monocrystalline silicon or polycrystalline silicon. In addition, it can be formed of another semiconductor material such as gallium arsenide (GaAs). The semiconductor substrate 10 is, for example, an n-type semiconductor substrate formed by doping an n-type dopant in a crystalline silicon material. As the n-type dopant, for example, phosphorus (P) can be given. The semiconductor substrate 10 functions as a photoelectric conversion substrate that absorbs incident light from the light-receiving surface side and generates photo-carriers (electrons and holes). By using crystalline silicon as the material of the semiconductor substrate 10, even in a case where the dark current is small and the intensity of the incident light is low, a relatively high output (stable output independent of illuminance) can be obtained.

[0021] ​​The first semiconductor layer 20 and the second semiconductor layer 30 induce carriers of mutually different polarities from the inside of the semiconductor substrate 10, thereby generating and collecting electric charges of different polarities. Specifically, in the case where the semiconductor substrate 10 is of n-type, the first semiconductor layer 20 is formed of a p-type semiconductor, and the second semiconductor layer 30 is formed of an n-type semiconductor. The first semiconductor layer 20 and the second semiconductor layer 30 can be formed of, for example, amorphous silicon material containing a dopant that imparts a desired conduction type. As a p-type dopant, boron (B) can be given as an example, and as an n-type dopant, phosphorus (P) can be given as an example.

[0022] The first semiconductor layer 20 and the second semiconductor layer 30 are formed in substantially complementary shapes on the back surface of the semiconductor substrate 10. That is, substantially the entire area of the back surface of the semiconductor substrate 10 is covered with either the first semiconductor layer 20 or the second semiconductor layer 30.

[0023] The first semiconductor layer 20 has a main functional portion 21 in which the first electrode pattern 40 is laminated, and an isolated portion 22 that is isolated from the main functional portion 21 and in which the first electrode pattern 40 is not laminated. The main functional portion 21 has a first base end portion 23 formed at an end portion on the first direction side of the semiconductor substrate 10 over substantially the entire length in the second direction intersecting the first direction, and a plurality of first collection portions 24 extending and protruding from the first base end portion 23 toward the other side of the first direction. The isolated portion 22 is formed in a linear shape over the entire length in the second direction at an end portion on the other side of the first direction of the semiconductor substrate 10.

[0024] The second semiconductor layer 30 has a second base end portion 31 adjacent to the first direction side of the isolated portion 22 and extending in the second direction, and a plurality of second collection portions 32 extending and protruding from the second base end portion 31 toward the first direction side.

[0025] The first collecting portion 24 and the second collecting portion 32 are preferably alternately formed in a constant width that is relatively small to the extent that the first electrode pattern 40 or the second electrode pattern 50 to be described later can be stacked, in order to reduce the moving distance of the carriers within the semiconductor substrate 10 to improve the photoelectric conversion efficiency. The first base end portion 23 and the second base end portion 31 are for the flow of the charges taken out by the first collecting portion 24 and the second collecting portion 32, so as to reduce the resistance, and are preferably larger in width than the first collecting portion 24 and the second collecting portion 32. The separation portion 22 does not participate in the photoelectric conversion, so the average width of the second direction of the separation portion 22 is preferably the minimum width that can be formed continuously in the first direction. Therefore, the average width of the first direction of the separation portion 22 is preferably smaller than the average width of the second direction of the first collecting portion 24, and the average width of the second direction of the first collecting portion 24 is preferably smaller than the average width of the first direction of the first base end portion 23. Specifically, as the lower limit of the average width of the first direction of the separation portion, 100 μm is preferable, and 200 μm is more preferable. On the other hand, as the upper limit of the average width of the first direction of the separation portion, 2000 μm is preferable, and 1000 μm is more preferable.

[0026] The first electrode pattern 40 and the second electrode pattern 50 are formed of a material having a relatively high conductivity such as metal. In addition, the first electrode pattern 40 and the second electrode pattern 50 can be a laminate of a transparent electrode layer composed of ITO (Indium Tin Oxide), ZnO (zinc oxide), or the like and a metal electrode layer mainly composed of metal, which is laminated to the first semiconductor layer 20 and the second semiconductor layer 30.

[0027] The first electrode pattern 40 is provided to take out the charges from the first semiconductor layer 20, and the second electrode pattern 50 is provided to take out the charges from the second semiconductor layer 30. The first electrode pattern 40 and the second electrode pattern 50 are laminated so as to leave a margin at the outer edge portions of the first semiconductor layer 20 (the main functional portion 21) and the second semiconductor layer 30, in order to prevent short circuit.

[0028] Specifically, the first electrode pattern 40 has a first bus bar electrode 41 laminated to the first base end portion 23 and extending in the second direction, and a plurality of first finger electrodes 42 extending and protruding from the first bus bar electrode 41 to the other side in the first direction and laminated to the respective first collecting portions 24. The second electrode pattern 50 has a second bus bar electrode 51 laminated to the second base end portion 31 and extending in the second direction, and a plurality of second finger electrodes 52 extending and protruding from the second bus bar electrode 51 to the one side in the first direction and laminated to the respective second collecting portions 32.

[0029] As above, for the solar cell unit 1, the first semiconductor layer 20 having a different conductive type from the semiconductor substrate 10 exists at both ends in the first direction throughout the entire length in the first direction (the first base end portion 23 and the separation portion 22). Therefore, when a plurality of solar cell units 1 are shingled in the first direction, even if the semiconductor substrate 10 contacts the first semiconductor layer 20 of the adjacent solar cell unit 1, the second semiconductor layer 30 is not contacted. Therefore, the solar cell unit 1 does not short-circuit at the time of shingling. Further, in the drawing, it seems that the semiconductor substrate 10 of the solar cell unit 1 on the back surface side and the first semiconductor layer 20 and the second semiconductor layer 30 of the solar cell unit 1 on the surface side do not contact due to the thickness of the first electrode pattern 40 and the second electrode pattern 50, but actually, the thickness of the first electrode pattern 40 and the second electrode pattern 50 is small, so the semiconductor substrate 10 of the solar cell unit 1 on the back surface side can easily contact the separation portion 22 due to a slight tilt or deformation.

[0030] <Manufacturing method of solar cell unit>

[0031] The solar cell unit 1 can be manufactured by the manufacturing method of a solar cell unit according to one embodiment of the present application. Figure 3

[0032] The manufacturing method of a solar cell unit of the present embodiment includes a process of forming a plurality of unit structures C on the back surface of a semiconductor wafer W (step S1: unit structure forming process) and a process of cutting the semiconductor wafer W at the boundaries of the unit structures C (step S2: cutting process). The semiconductor wafer W is a larger plate-shaped semiconductor that can be cut into a plurality of semiconductor substrates 10 by cutting. The unit structure C is a concept that aggregates the constituent elements other than the semiconductor substrate 10 of each solar cell unit, that is, the first semiconductor layer 20, the second semiconductor layer 30, the first electrode pattern 40, and the second electrode pattern 50.

[0033] In the unit structure forming process of step S1, as shown in FIG. 1, a plurality of unit structures C are formed on the semiconductor wafer W in the first direction in alignment and in the same orientation. Figure 4 Figure 4 indicates a cross section at the same position as Figure 2 Figure 1 ​​​A-A line. As is clear from the description of the solar cell unit 1, the first semiconductor layer 20 has a main functional portion 21 and an isolation portion 22, the main functional portion 21 has a first base end portion 23 formed at an end portion of each unit configuration C on the first direction side and extending over the entire length of the second direction intersecting the first direction, and a plurality of first collection portions 24 extending and projecting from the first base end portion 23 toward the other side of the first direction, and the first electrode pattern 40 is stacked, and the isolation portion 22 is formed in a linear shape at an end portion of each unit configuration on the other side of the first direction and extending over the entire length of the second direction, and the first electrode pattern 40 is not stacked.

[0034] In the unit configuration formation step, the main functional portion 21 of the unit configuration C on the other side of the first direction and the isolation portion 22 of the unit configuration C adjacent on the first direction side are formed continuously. That is, by forming the first semiconductor layer 20 so as to extend across the boundary of the unit configuration C (indicated by a dotted line), the main functional portion 21 of the unit configuration C on the other side of the first direction and the isolation portion 22 of the unit configuration C on the first direction side are formed integrally. That is, in the first semiconductor layer 20, Figure 4 In the first semiconductor layer 20 of the unit configuration C on the right side, the first semiconductor layer 20 extends slightly beyond the boundary of the unit configuration C to the unit configuration C on the left side, and the portion beyond the boundary of the unit configuration C constitutes the isolation portion 22 of the unit configuration C on the left side.

[0035] The first semiconductor layer 20 and the second semiconductor layer 30 can be formed by forming a resist pattern and selectively stacking a semiconductor material using a film formation technique such as CVD. The first electrode pattern 40 and the second electrode pattern 50 can be formed, for example, by etching of a metal layer, printing and firing of a conductive paste, and the like, and in the etching of the metal layer, the metal layer is formed by plating using a seed layer formed by sputtering or the like as an attachment body.

[0036] In the cutting step of step S2, the semiconductor wafer W is cut along the boundary of the unit configuration C, thereby separating the main functional portion 21 of the unit configuration C on the other side of the first direction and the isolation portion 22 of the unit configuration C adjacent on the first direction side, and cutting out the solar cell unit 1.

[0037] The cutting of the semiconductor wafer W can be performed by, for example, forming a scribe groove by laser irradiation, milling, or the like, and applying bending to the semiconductor wafer W.

[0038] <Solar Cell Module>

[0039] Figure 5is a sectional view of a solar cell module M having a plurality of solar cell units 1. The solar cell module M has a plurality of solar cell strings 100 each formed by arranging a plurality of solar cell units 1 in a row and connecting them, a plate-shaped surface protection material 200 covering the surface side of the plurality of solar cell strings 100, a plate-shaped or sheet-shaped back surface protection material 300 covering the back surface side of the plurality of solar cell strings 100, and a sealing material 400 filled between the surface protection material 200 and the back surface protection material 300.

[0040] The solar cell string 100 has a plurality of solar cell units 1 arranged in a row in a first direction, and an interconnector 2 connecting between adjacent solar cell units. In the solar cell string 100, the end portion on the first direction side of the solar cell unit 1 is arranged so as to overlap the end portion on the first direction side of the back surface side of the adjacent solar cell unit 1. The interconnector 2 is formed of a conductor such as a metal foil or a metal mesh wire, and connects the first bus bar electrode 41 of the solar cell unit 1 overlapping the surface side and the second bus bar electrode 51 of the solar cell unit 1 overlapping the back surface side.

[0041] In the solar cell string, as shown in the drawing, the interconnector 2 can come into contact with the isolation portion 22 of the first semiconductor layer 20, but the isolation portion 22 and the main functional portion 21 that participates in photoelectric conversion are isolated, so even if the interconnector 2 comes into contact, no adverse situation occurs.

[0042] The surface protection material 200 covers the surface of the solar cell string 100 via the sealing material 400, thereby protecting the solar cell string 100. The surface protection material 200 is preferably formed of a material that is transparent and has damage resistance, such as glass, polycarbonate, acrylic resin, or the like, and has excellent weather resistance. Specifically, as the material of the surface protection material 200, for example, a transparent resin such as acrylic resin or polycarbonate resin, glass, or the like can be given. In addition, the surface of the surface protection material 200 can be processed into a concave-convex shape or covered with an antireflection coating in order to suppress reflection of light. The surface protection material 200 can have a light-shielding region in the outer peripheral portion.

[0043] The surface protection material 200 preferably has a sufficient thickness in order to have strength capable of maintaining the shape of the solar cell module M. In addition, by using a surface protection material 200 that is formed into a desired shape in advance, a solar cell module M of a desired shape can be obtained.

[0044] The solar cell string 100 can be formed to have a length in the first direction that is substantially equal to a length of a light-transmitting region on an inner side of a light-shielding region of the surface protection material 200. Thus, the effective area of the solar cell string 100 that receives light can be increased, and a decrease in photoelectric conversion efficiency caused by light not being incident on a portion of the solar cell unit 1 at the end of the solar cell string 100 can be prevented. In addition, a plurality of solar cell strings 100 can be connected to each other by a wiring material not shown.

[0045] The back surface protection material 300 is a layer that protects the back surface side of the solar cell string 100. The material of the back surface protection material 300 is not particularly limited, but is preferably a material that prevents the penetration of water and the like (high water resistance). Specifically, the back surface protection material 300 can be formed of, for example, a resin such as glass, polyethylene terephthalate (PET), an acrylic resin, polyethylene (PE), an olefin-based resin, a fluorine-containing resin, a silicon-containing resin, or the like. In addition, the back surface protection material 300 can also be a laminate of a layer of a resin and a layer of a metal such as an aluminum foil. In addition, in order to make the gaps between the solar cell strings 100 unnoticeable and improve the aesthetic appearance of the solar cell module M, the color (light reflection characteristics) of the back surface protection material 300 when viewed from the surface side is preferably similar to the color of the surface side of the solar cell unit 1.

[0046] The sealing material 400 seals the solar cell string 100 in the space between the surface protection material 200 and the back surface protection material 300, and suppresses the degradation of the solar cell string 100 due to moisture and the like. The sealing material 400 is formed of a material that has transparency and adhesion to the surface protection material 200 and the solar cell string 100. The material that forms the sealing material 400 is preferably thermoplastic so as to be able to seal the gaps of the surface protection material 200 and the solar cell string 100 by heat pressing. Specifically, as the material that forms the sealing material 400, for example, a resin composition in which an ethylene / vinyl acetate copolymer (EVA), an ethylene / α-olefin copolymer, an ethylene / vinyl acetate / triallyl isocyanurate (EVAT), polyvinyl butyral (PVB), an acrylic resin, a polyurethane resin, a silicone resin, or the like is used as a main component can be used.

[0047] The above describes embodiments of the present application, but the present application is not limited to the above-described embodiments, and various modifications and alterations can be made. Further, the solar cell unit according to the present application can have a configuration other than the configuration described in the above-described embodiments. For example, the solar cell unit according to the present application can have an intrinsic semiconductor layer that separates the first semiconductor layer and the second semiconductor layer. Further, the planar shape of the main functional portion of the first semiconductor layer and the planar shape of the second semiconductor layer, and even the planar shape of the first electrode pattern and the second electrode pattern, can be appropriately changed.

[0048] Explanation of Reference Signs

[0049] 1...solar cell unit; 2...interconnector; 10...semiconductor substrate; 20...first semiconductor layer; 21...main functional portion; 22...separation portion; 23...first base end portion; 24...first collecting portion; 30...second semiconductor layer; 31...second base end portion; 32...second collecting portion; 40...first electrode pattern; 41...first busbar electrode; 42...first finger electrode; 50...second electrode pattern; 51...second busbar electrode; 52...second finger electrode; 100...solar cell string; 200...surface protective material; 300...back surface protective material; 400...sealing material; C...unit configuration; M...solar cell module; W...semiconductor wafer.

Claims

1. A solar cell unit, characterized in that, have: A semiconductor substrate having a first conductivity type; A first semiconductor layer and a second semiconductor layer are formed on the back side of the semiconductor substrate. The first semiconductor layer has a different conductivity type than the semiconductor substrate, and the second semiconductor layer has the same conductivity type as the semiconductor substrate. as well as A first electrode pattern and a second electrode pattern, wherein the first electrode pattern is stacked on the first semiconductor layer, and the second electrode pattern is stacked on the second semiconductor layer. The first semiconductor layer has: The main functional part has a first base end and a plurality of first collection portions, and the first electrode pattern is stacked thereon. The first base end is formed along the entire length of a second direction that intersects the first direction at one end of the semiconductor substrate in a first direction. The plurality of first collection portions extend and protrude from the first base end to the other side of the first direction. and The isolation portion, extending along the entire length of the second direction from the end on the other side of the first direction of the semiconductor substrate, is linear and does not overlap with the first electrode pattern. The second semiconductor layer has a second base end and a plurality of second collection portions. The second base end is adjacent to the first direction side of the isolation portion and extends in the second direction. The plurality of second collection portions extend and protrude from the second base end towards the first direction side.

2. The solar cell unit according to claim 1, characterized in that, The average width of the isolation portion in the first direction is less than the average width of the first collection portion in the second direction, and the average width of the first collection portion in the second direction is less than the average width of the first base end portion in the first direction.

3. The solar cell unit according to claim 1 or 2, characterized in that, The average width of the isolation portion in the first direction is less than 2000 μm.

4. A method for manufacturing a solar cell unit, characterized in that, It has the following processes: Multiple unit structures are formed on the back side of a semiconductor wafer having a first conductivity type. The multiple unit structures each have a first semiconductor layer and a second semiconductor layer, as well as a first electrode pattern and a second electrode pattern. The first semiconductor layer has a different conductivity type than the semiconductor wafer, and the second semiconductor layer has the same conductivity type as the semiconductor wafer. The first electrode pattern is stacked on the first semiconductor layer, and the second electrode pattern is stacked on the second semiconductor layer. and The semiconductor wafer is cut at the boundary of the cell structure. The plurality of units are arranged in a first direction and formed in the same orientation. The first semiconductor layer has: The main functional unit has a first base end and a plurality of first collection portions, and the first electrode pattern is stacked thereon. The first base end is formed throughout the entire length of a second direction intersecting the first direction at one end of the unit structure in the first direction. The plurality of first collection portions extend and protrude from the first base end to the other side of the first direction. and The isolation section, extending along the entire length of the second direction from the end on the other side of the first direction in the unit structure, is linear and does not overlap with the first electrode pattern. In the process of forming the unit structure, the main functional part and the isolation part of the unit structure adjacent to each other on one side of the first direction are formed continuously. In the process of cutting the semiconductor wafer, the main functional part and the isolation portion constructed by the unit adjacent to it on the first direction side are separated.

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