Connected solar-cell structure

Abstract

A connected solar-cell structure (10) according to an embodiment includes solar cell elements (1) and wiring lines (17, 18). Each solar cell element (1) has a monolithic structure and has extraction electrodes (7, 8) at both ends along a first direction (Y). The wiring lines (17, 18) are connected to the extraction electrodes (7, 8) and extend in a second direction (X) crossing the first direction (Y). A plurality of solar cell elements (1) are arranged side by side in the first direction (Y). Solar cell elements (1) adjacent to each other in the first direction (Y) are arranged so that the extraction electrodes (7, 8) having the same polarity are adjacent to each other along the first direction (Y). The wiring lines (17, 18) are connected to both the extraction electrodes (7, 8) having the same polarity which are adjacent to each other along the first direction (Y).

Description

Solar cell connector

[0001] SUMMARY OF THE INVENTION An embodiment of the present invention relates to a solar cell assembly.

[0002] A solar cell assembly includes a plurality of solar cell elements arranged side by side and wiring. The wiring connects the plurality of solar cell elements in series or in parallel. The solar cell assembly is required to have a reduced number of wirings.

[0003] Japanese Patent Application Laid-Open No. 2003-282903

[0004] The problem to be solved by the present invention is to provide a solar cell assembly that can reduce the number of wires.

[0005] A solar cell assembly according to a first aspect of the embodiment includes a solar cell element and wiring. The solar cell element has a monolithic structure and has extraction electrodes at both ends in a first direction. The wiring is connected to the extraction electrodes and extends in a second direction intersecting the first direction. A plurality of solar cell elements are arranged side by side in the first direction. Solar cell elements adjacent in the first direction are arranged such that extraction electrodes of the same polarity are adjacent in the first direction. The wiring is connected across the extraction electrodes of the same polarity adjacent in the first direction.

[0006] In the solar cell assembly of Aspect 2, the solar cell assembly of Aspect 1 includes a plurality of solar cell elements arranged side by side in a first direction and a second direction. The solar cell elements adjacent to each other in the second direction are arranged such that the extraction electrodes of the same polarity are adjacent to each other in the second direction. The wiring is continuously connected to the extraction electrodes of the same polarity adjacent to each other in the second direction.

[0007] In the solar cell assembly of Aspect 3, the solar cell elements adjacent to each other in the first direction in the solar cell assembly of Aspect 1 or 2 are arranged adjacent to each other in the first direction with an electrical insulator interposed therebetween.

[0008] In the solar cell assembly of embodiment 4, the electrical insulator in the solar cell assembly of embodiment 3 is integrated with the wiring.

[0009] The solar cell assembly of Aspect 5 is the solar cell assembly of any one of Aspects 1 to 4, further comprising end wiring connected only to the extraction electrode located at the end in the first direction. The width of the end wiring in the first direction is smaller than the width of the wiring in the first direction.

[0010] A solar cell assembly of Aspect 6 is the solar cell assembly of any one of Aspects 1 to 5, wherein the solar cell element includes a transparent cuprous oxide semiconductor.

[0011] In the solar cell assembly of Aspect 7, in the solar cell assembly of any one of Aspects 1 to 5, the solar cell element includes a perovskite semiconductor.

[0012] 1. A solar cell assembly according to an embodiment. A solar cell element according to an embodiment. A part of a side cross-sectional view taken along line III-III in FIG. 2. A part of a side cross-sectional view taken along line IV-IV in FIG. 1. An explanatory diagram of a solar cell assembly according to a first modified example of the embodiment.

[0013] Hereinafter, a solar cell assembly according to an embodiment will be described with reference to the drawings. Fig. 1 is a plan view of a solar cell assembly 10. The solar cell assembly 10 has a solar cell element (solar cell) 1. Fig. 2 is a plan view of the solar cell element 1. Fig. 3 is a part of a side cross-sectional view taken along line III-III in Fig. 2. The solar cell element 1 has a substrate 2, a semiconductor layer 3, a scribe line 5, a positive electrode (extraction electrode) 7, and a negative electrode (extraction electrode) 8.

[0014] In the present application, the X direction, Y direction, and Z direction of the Cartesian coordinate system are defined as follows. The X direction (second direction) is parallel to the surface of the solar cell element 1 and is the direction in which the positive electrode 7 and the negative electrode 8 extend. The X direction is the left-right direction of the paper in FIG. 2 , with the +X direction being the left direction of the paper and the −X direction being the right direction of the paper. The Y direction (first direction) is parallel to the surface of the solar cell element 1 and is the direction in which the positive electrode 7 and the negative electrode 8 are aligned. The +Y direction is the direction from the positive electrode 7 to the negative electrode 8, and the −Y direction is the direction from the negative electrode 8 to the positive electrode 7. The Z direction is a direction perpendicular to the surface of the solar cell element 1. As shown in FIG. 3 , the +Z direction is the direction in which the semiconductor layer 3 is formed on the substrate 2, and the −Z direction is the opposite direction to the +Z direction.

[0015] The substrate 2 is a glass substrate or a flexible film substrate. The semiconductor layer 3 is a transparent cuprous oxide (CuO) ２ O) semiconductors, perovskite semiconductors, etc. A back surface transparent electrode 4a is disposed in the −Z direction of the semiconductor layer 3, and a front surface transparent electrode 4b is disposed in the +Z direction. A metal collecting electrode and an anti-reflection film (both not shown) are disposed in this order in the +Z direction of the front surface transparent electrode 4b.

[0016] The semiconductor layer 3 containing a transparent cuprous oxide semiconductor is formed by stacking p-type Cu ２ The rear transparent electrode 4a includes a p-type CuO layer, an n-type ZnGeO (ZGO: zinc germanate) layer, and a second n-type layer (not shown). ２ The O layer is formed by reactive sputtering using a Cu target with oxygen gas added. The n-type ZGO is formed by atomic layer deposition. The p-type Cu ２ The O layer and the n-type ZGO form a hetero pn junction.

[0017] Perovskite semiconductors at least partially contain a perovskite structure. The perovskite structure is one of the crystal structures, and is the same as the perovskite. A typical perovskite structure is composed of ions A, B, and X, and is represented by the following general formula (1): ABX ３ ... (1)

[0018] A primary ammonium ion can be used as A. Specifically, CH ３ NH ３ ＋ , C ２ H ５ NH ３ ＋ , C ３ H ７ NH ３ ＋ , C ４ H ９ NH ３ ＋ , and HC(NH ２ ) ２ ＋ and CH ３ NH ３ ＋is preferable, but not limited to this. ＋ , Rb ＋ , 1,1,1-trifluoro-ethylammonium iodide (FEAI) are also preferred, but are not limited to these. ２＋ or Sn ２＋ Examples of divalent metal ions that can be used include, but are not limited to, Cl. － ,Br － or I － The materials constituting the ions A, B, and X may be single or mixed. The constituting ions are ABX ３ It can function without necessarily matching the stoichiometric ratio.

[0019] The scribe lines 5 are P1, P2, and P3 scribes of a so-called monolithic structure. That is, a rear transparent electrode 4a is formed in the +Z direction of the substrate 2, and the rear transparent electrode 4a is divided by the P1 scribe. Next, a semiconductor layer 3 is formed in the +Z direction of the rear transparent electrode 4a, and the semiconductor layer 3 is divided by the P2 scribe. Next, a front transparent electrode 4b is formed in the +Z direction of the semiconductor layer 3, and the front transparent electrode 4b is divided by the P3 scribe.

[0020] As shown in Fig. 2, the scribe lines 5 extend in the X direction. A plurality of scribe lines 5 are formed side by side in the Y direction. The semiconductor layer 3 is divided by the scribe lines 5 into a plurality of cells lined up in the Y direction. As shown in Fig. 3, the plurality of cells are electrically connected in series to form a so-called monolithic module. The power generation voltage of the solar cell element 1 is adjusted by the number of cells divided by the scribe lines 5.

[0021] The solar cell element 1 may be a tandem solar cell (tandem solar cell). A tandem solar cell has a top cell arranged in the +Z direction of the substrate 2 and a bottom cell arranged in the -Z direction. The top cell includes the above-mentioned transparent cuprous oxide semiconductor or perovskite semiconductor. The bottom cell includes a silicon (Si) semiconductor. Transparent electrodes are arranged in the ±Z directions of the silicon semiconductor. The top cell and bottom cell may be electrically insulated from each other.

[0022] As shown in Fig. 2, the extraction electrodes 7, 8 are arranged on the surface of the solar cell element 1 in the +Z direction. The length of the extraction electrodes 7, 8 in the X direction is equal to the length of the solar cell element 1 in the X direction. The extraction electrodes 7, 8 are arranged at both ends of the solar cell element 1 in the Y direction. The positive electrode 7 is arranged on one side in the Y direction, and the negative electrode 8 is arranged on the other side in the Y direction. Electric power generated by the solar cell element 1 is extracted to the outside from the extraction electrodes 7, 8.

[0023] Compared to a typical Si solar cell, the amount of current generated by a solar cell element 1 including a transparent cuprous oxide semiconductor or the like is small. Therefore, in the solar cell assembly 10, a plurality of solar cell elements 1 are connected in parallel.

[0024] 1 , the solar cell connection assembly 10 has a positive electrode wiring (wiring) 17, an end positive electrode wiring (end wiring) 17e, a positive electrode output wiring (output wiring) 12, a negative electrode wiring (wiring) 18, an end negative electrode wiring (end wiring) 18e, and a negative electrode output wiring (output wiring) 13. For example, these wirings are bus bars formed of copper ribbon or the like.

[0025] The positive wire 17 and the end positive wire 17e, as well as the negative wire 18 and the end negative wire 18e, extend in the X direction. The end wires 17e, 18e are arranged at both ends of the solar cell assembly 10 in the Y direction. The wires 17, 18 are arranged inside both ends of the solar cell assembly 10 in the Y direction. The positive wire 17 and the end positive wire 17e are connected to the positive electrode 7 of the solar cell element 1. The negative wire 18 and the end negative wire 18e are connected to the negative electrode 8 of the solar cell element 1.

[0026] The output wires 12, 13 extend in the Y direction. The output wires 12, 13 are arranged at both ends of the solar cell assembly 10 in the X direction. The positive output wire 12 is connected to the positive wire 17 and the end positive wire 17e. The negative output wire 13 is connected to the negative wire 18 and the end negative wire 18e. Electric power generated in the solar cell assembly 10 is extracted to the outside through the output wires 12, 13.

[0027] The solar cell assembly 10 has a plurality of solar cell elements 1. The solar cell elements 1 are arranged side by side in the X direction and the Y direction.

[0028] FIG. 4 is a partial side cross-sectional view taken along line IV-IV in FIG. 1 . Solar cell elements 1 adjacent in the Y direction are arranged so that their extraction electrodes 7, 8 of the same polarity are adjacent in the Y direction. For example, the multiple solar cell elements 1 include a first solar cell element 1a, a second solar cell element 1b, and a third solar cell element 1c arranged side by side from the −Y direction to the +Y direction. The first solar cell element 1a is arranged so that its positive electrode 7 is located at its end in the +Y direction. The second solar cell element 1b is arranged so that its positive electrode 7 is located at its end in the −Y direction and its negative electrode 8 is located at its end in the +Y direction. The third solar cell element 1c is arranged so that its negative electrode 8 is located at its end in the −Y direction. Thus, the first solar cell element 1a and the second solar cell element 1b adjacent in the Y direction are arranged so that their positive electrodes 7 are adjacent in the Y direction. The second solar cell element 1b and the third solar cell element 1c adjacent in the Y direction are arranged so that their negative electrodes 8 are adjacent in the Y direction.

[0029] The wiring 17, 18 is connected across the extraction electrodes 7, 8 of the same polarity that are adjacent in the Y direction. That is, the positive wiring 17 is connected across the positive electrodes 7 that are adjacent in the Y direction of the solar cell elements 1 that are adjacent in the Y direction. The negative wiring 18 is connected across the negative electrodes 8 that are adjacent in the Y direction of the solar cell elements 1 that are adjacent in the Y direction. The wiring 17, 18 is connected to the extraction electrodes 7, 8 by soldering or the like. The width of the wiring 17, 18 in the Y direction is wider than the distance between the solar cell elements 1 that are adjacent in the Y direction.

[0030] 1 , the end wirings 17e, 18e are connected only to the extraction electrodes 7, 8 located at the Y-direction ends of the solar cell connected body 10. That is, the end positive wiring 17e is connected only to the positive electrode 7 located at the Y-direction end of the solar cell connected body 10. The end negative wiring 18e is connected only to the negative electrode 8 located at the Y-direction end of the solar cell connected body 10. The Y-direction width of the end wirings 17e, 18e is narrower than the Y-direction width of the wirings 17, 18. The respective widths are set according to the current densities of the wirings 17, 18 and the end wirings 17e, 18e.

[0031] As shown in FIG. 1 , solar cell elements 1 adjacent in the X direction are arranged so that extraction electrodes 7, 8 of the same polarity are adjacent in the X direction. For example, the multiple solar cell elements 1 include a fourth solar cell element 1d adjacent in the +X direction to a second solar cell element 1b. As described above, the second solar cell element 1b is arranged so that the positive electrode 7 is located at the end in the −Y direction and the negative electrode 8 is located at the end in the +Y direction. The fourth solar cell element 1d is similarly arranged so that the positive electrode 7 is located at the end in the −Y direction and the negative electrode 8 is located at the end in the +Y direction. As a result, the second solar cell element 1b and the fourth solar cell element 1d adjacent in the X direction are arranged so that their positive electrodes 7 are adjacent in the X direction and their negative electrodes 8 are adjacent in the X direction.

[0032] The wirings 17, 18 and the end wirings 17e, 18e are continuously connected to the extraction electrodes 7, 8 of the same polarity that are adjacent in the X direction. The positive wiring 17 and the end positive wiring 17e are continuously connected to the positive electrodes 7 that are adjacent in the X direction of the solar cell elements 1 that are adjacent in the X direction. The negative wiring 18 and the end negative wiring 18e are continuously connected to the negative electrodes 8 that are adjacent in the X direction of the solar cell elements 1 that are adjacent in the X direction. The wirings 17, 18 and the end wirings 17e, 18e are continuously connected to all the solar cell elements 1 lined up in the X direction. The X-direction ends of the wirings 17, 18 and the end wirings 17e, 18e are connected to the extraction wirings 12, 13.

[0033] As described above in detail, the solar cell assembly 10 of the embodiment has the solar cell element 1 and the wiring 17, 18. The solar cell element 1 has a monolithic structure and has the extraction electrodes 7, 8 at both ends in the Y direction. The wiring 17, 18 is connected to the extraction electrodes 7, 8 and extends in the X direction intersecting the Y direction. A plurality of solar cell elements 1 are arranged side by side in the Y direction. The solar cell elements 1 adjacent in the Y direction are arranged so that the extraction electrodes 7, 8 of the same polarity are adjacent in the Y direction. The wiring 17, 18 is connected across the extraction electrodes 7, 8 of the same polarity adjacent in the Y direction.

[0034] In contrast, in other solar cell connections, solar cell elements adjacent in the Y direction are arranged so that their extraction electrodes of opposite polarities are adjacent in the Y direction. In this solar cell connection, the positive and negative electrodes of the multiple solar cell elements are arranged alternately along the Y direction. The wiring of this solar cell connection is not connected across the extraction electrodes of opposite polarities adjacent in the Y direction. Separate wiring is connected to each of the extraction electrodes of opposite polarities adjacent in the Y direction.

[0035] In the solar cell assembly 10 of the embodiment described above, the solar cell elements 1 adjacent in the Y direction are arranged so that the extraction electrodes 7, 8 of the same polarity are adjacent in the Y direction. The wiring 17, 18 is connected across the extraction electrodes 7, 8 of the same polarity adjacent in the Y direction. This makes it possible to reduce the number of wiring 17, 18. Accordingly, the cost of the solar cell assembly 10 is reduced.

[0036] In the other solar cell assembly described above, solar cell elements adjacent in the Y direction are arranged so that their extraction electrodes of different polarities are adjacent in the Y direction. To prevent short-circuiting between the extraction electrodes of different polarities, solar cell elements adjacent in the Y direction are arranged with a considerable insulating distance between them. This increases the size of the solar cell assembly and reduces the effective power generation area.

[0037] In contrast, in the solar cell assembly 10 of the embodiment, the solar cell elements 1 adjacent in the Y direction are arranged so that the extraction electrodes 7, 8 of the same polarity are adjacent in the Y direction. Since there is no need to prevent short-circuiting between the extraction electrodes 7, 8 of the same polarity, the solar cell elements 1 adjacent in the Y direction are arranged close to each other. This reduces the size of the solar cell assembly 10 and increases the effective power generation area.

[0038] The wiring of the other solar cell connections described above is not connected across adjacent extraction electrodes of opposite polarity in the Y direction. Therefore, the solar cell connection is not continuous in the Y direction. In contrast, the wiring 17, 18 of the solar cell connection 10 of the embodiment is connected across adjacent extraction electrodes 7, 8 of the same polarity in the Y direction. This makes the solar cell connection 10 continuous and integrated in the Y direction. This makes it easier to manufacture and handle the solar cell connection 10. Furthermore, the structural strength of the solar cell connection 10 is improved.

[0039] In the solar cell assembly 10 of the embodiment, multiple solar cell elements 1 are arranged side by side in the Y and X directions. Solar cell elements 1 adjacent in the X direction are arranged so that the extraction electrodes 7, 8 of the same polarity are adjacent in the X direction. Wiring 17, 18 are continuously connected to the extraction electrodes 7, 8 of the same polarity adjacent in the X direction. This makes the wiring 17, 18 linearly extending in the X direction, thereby reducing the cost of the solar cell assembly 10.

[0040] The solar cell assembly 10 of the embodiment has end wirings 17e, 18e connected only to the extraction electrodes 7, 8 located at the ends in the Y direction. The width of the end wirings 17e, 18e in the Y direction is narrower than the width of the wirings 17, 18 in the Y direction. This reduces the cost of the solar cell assembly 10. Furthermore, the solar cell assembly 10 is made smaller and its effective power generation area is increased.

[0041] The solar cell element 1 may include a transparent cuprous oxide semiconductor. The solar cell element 1 may include a perovskite semiconductor. This allows the solar cell assembly 10 to exhibit high power generation efficiency.

[0042] 5 is an explanatory diagram of a solar cell assembly 10 according to a first modified example of the embodiment. FIG. 5 is a partial side cross-sectional view of a portion corresponding to line IV-IV in FIG. 1 . As described above, in the solar cell assembly 10 according to the embodiment, it is not necessary to prevent short-circuiting between adjacent extracting electrodes 7, 8 of the same polarity in the Y direction between solar cell elements 1 adjacent in the Y direction. However, there is a possibility of short-circuiting occurring between the side surfaces of solar cell elements 1 adjacent in the Y direction. Therefore, as shown in FIG. 4 , solar cell elements 1 adjacent in the Y direction are arranged with a small gap in the Y direction.

[0043] In contrast, in a solar cell assembly 10 of a first modified example shown in Fig. 5, an electrical insulator 20 is disposed between solar cell elements 1 adjacent in the Y direction. The side surfaces of the solar cell elements 1 adjacent in the Y direction are disposed in close contact with the Y-direction side surface of the electrical insulator 20. For example, the electrical insulator 20 is a resin sheet or the like that is separate from the solar cell elements 1. The electrical insulator 20 may also be an insulating film formed on the side surface of the solar cell element 1.

[0044] In this way, in the solar cell assembly 10 of the first modified example, the solar cell elements 1 adjacent in the Y direction are arranged adjacent to each other in the Y direction with the electrical insulator 20 interposed therebetween. This makes the distance between the solar cell elements 1 adjacent in the Y direction extremely small. Therefore, the solar cell assembly 10 is made smaller and the effective power generation area is increased.

[0045] The electrical insulator 20 may be integral with the wiring 17, 18. In this case, the electrical insulator 20 is molded integrally with the wiring 17, 18, or is fixed to the wiring 17, 18 with an adhesive or the like. If the electrical insulator 20 is integral with the wiring 17, 18, it becomes easier to attach the electrical insulator 20 to the solar cell connection assembly 10.

[0046] 1 , in the solar cell assembly 10 of the embodiment, the solar cell elements 1 are arranged side by side in the Y direction and the X direction. Alternatively, the solar cell elements 1 may be arranged in a row only in the Y direction.

[0047] As shown in FIG. 1 , between solar cell elements 1 adjacent in the X direction, there is no need to prevent short-circuiting between adjacent extraction electrodes 7, 8 of the same polarity in the X direction. Furthermore, there is little possibility of short-circuiting occurring between the side surfaces of solar cell elements 1 adjacent in the X direction. Therefore, solar cell elements 1 adjacent in the X direction may be arranged with a small gap in the X direction. Note that solar cell elements 1 adjacent in the X direction may be arranged in close contact with each other. Furthermore, solar cell elements 1 adjacent in the X direction may be arranged adjacent to each other in the X direction with an electrical insulator interposed therebetween.

[0048] According to at least one of the embodiments described above, the wirings 17 and 18 are provided so as to be connected across the extraction electrodes 7 and 8 of the same polarity that are adjacent in the Y direction. This makes it possible to reduce the number of wirings 17 and 18.

[0049] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents.

[0050] 1... solar cell element, 7... positive electrode, extraction electrode, 8... negative electrode, extraction electrode, 10... solar cell connection body, 17... positive electrode wiring, wiring, 18... negative electrode wiring, wiring, 17e... end positive electrode wiring, end wiring, 18e... end negative electrode wiring, end wiring, 20... electrical insulator

Claims

1. A solar cell connection comprising: a solar cell element having a monolithic structure and having extraction electrodes at both ends in a first direction; and wiring connected to the extraction electrodes and extending in a second direction intersecting the first direction, wherein a plurality of the solar cell elements are arranged side by side in the first direction, the solar cell elements adjacent in the first direction are arranged such that the extraction electrodes of the same polarity are adjacent in the first direction, and the wiring is connected across the extraction electrodes of the same polarity adjacent in the first direction.

2. The solar cell connection assembly described in claim 1, wherein a plurality of the solar cell elements are arranged side by side in the first direction and the second direction, the solar cell elements adjacent in the second direction are arranged such that the extraction electrodes of the same polarity are adjacent in the second direction, and the wiring is continuously connected to the extraction electrodes of the same polarity adjacent in the second direction.

3. The solar cell connection assembly according to claim 1 or 2, wherein the solar cell elements adjacent in the first direction are arranged adjacent in the first direction with an electrical insulator interposed therebetween.

4. The solar cell connection assembly according to claim 3, wherein the electrical insulator is integral with the wiring.

5. A solar cell connection assembly as described in claim 1 or 2, having end wiring connected only to the extraction electrode located at the end in the first direction, and the width of the end wiring in the first direction is narrower than the width of the wiring in the first direction.

6. The solar cell assembly according to claim 1 or 2, wherein the solar cell element includes a transparent cuprous oxide semiconductor.

7. The solar cell assembly according to claim 1 or 2, wherein the solar cell element includes a perovskite semiconductor.

Images