A back electrode functional film and a method for leading out a positive electrode of a thin film photovoltaic module
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- QUZHOU MICROQUANTA RENEWABLE ENERGY TECHN CO LTD
- Filing Date
- 2022-02-22
- Publication Date
- 2026-07-14
Smart Images
Figure CN116682867B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of thin-film photovoltaic module manufacturing technology, and specifically relates to a back electrode functional film, a thin-film photovoltaic module, and a method for leading out the positive electrode. Background Technology
[0002] A back electrode functional film is set inside the thin-film photovoltaic module, and the busbars, which serve as the positive and negative electrode leads, are generally directly attached to the back electrode functional film. The traditional methods of leading out the positive and negative electrodes of thin-film photovoltaic modules are mostly limited by the width of the busbars. In particular, the positive electrode is a non-power-generating area, and the proportion of effective area occupied by it often affects the power generation of the thin-film photovoltaic module. Summary of the Invention
[0003] The technical problem to be solved by the present invention is to provide a back electrode functional film, a thin-film photovoltaic module, and a method for leading out the positive electrode, which reduces the area of the positive electrode of the module without changing the size of the busbar, thereby increasing the power generation of the thin-film photovoltaic module.
[0004] This invention is implemented as follows: a back electrode functional film is provided, comprising a substrate and a back electrode layer disposed on the surface of the substrate. The back electrode layer includes a battery region located in the middle and an edge region located around the battery region. Multiple scribe lines are formed within the battery region to divide it into multiple independently separated sub-battery regions. The leftmost sub-battery region is the positive electrode region, and the rightmost sub-battery region is the negative electrode region, with the width of the positive electrode region being smaller than the width of the negative electrode region. A positive electrode busbar start-up area, a positive electrode busbar end-up area, a negative electrode busbar start-up area, and a negative electrode busbar end-up area are respectively provided at the upper and lower ends of the positive and negative electrode regions, wherein the positive electrode busbar start-up area... The positive electrode busbar termination area and the positive electrode busbar termination area are stepped with large and small ends, respectively. The small end is electrically connected to the positive cell area it is located in. The width of the small end is not greater than the width of the positive electrode area it is located in and does not exceed the position of the adjacent scribed groove. The width of the large end is not greater than the width of the sub-cell area. Except for retaining the back electrode layer of the positive electrode busbar termination area and the positive electrode busbar start-end area and the positive electrode busbar termination area, the back electrode layer at other positions in the edge area is removed to expose the substrate. Busbars as positive and negative electrode leads are respectively set on the large end areas of the positive electrode busbar start-end area and the positive electrode busbar termination area. The width of the positive electrode busbar start-end area and the positive electrode busbar termination area is not less than the width of the busbar.
[0005] Furthermore, the width of the starting and ending lead-out areas of the negative electrode busbar is not greater than the width of the negative electrode area and does not exceed the location of the adjacent scribing groove.
[0006] Furthermore, the sum of the heights of the large and small ends of the positive electrode busbar starting area and the positive electrode busbar ending area is less than the height of the edge area; the ratio of the heights of the large and small ends of the positive electrode busbar starting area and the positive electrode busbar ending area is 1:1 to 1:4.
[0007] This invention is implemented as follows, and also provides a thin-film photovoltaic module having a back electrode functional film as described above disposed inside it.
[0008] This invention is implemented as follows, and also provides a method for leading out the positive electrode, comprising the following steps:
[0009] Step 1: The substrate with the pre-formed front electrode layer includes a battery region in the middle and an edge region around the battery region. Multiple P1 grooves are formed on the battery region using P1 scribe lines, with the bottom of each P1 groove exposed on the substrate. These parallel P1 grooves divide the front electrode layer of the battery region into several independent sub-battery regions. The leftmost sub-battery region is the positive electrode region, and the rightmost sub-battery region is the negative electrode region. The width of the positive electrode region is smaller than the width of the negative electrode region. Then, the front electrode layers at the top and bottom of the positive and negative electrode regions are removed respectively. The electrode layer is exposed to the substrate, resulting in the P1 positive electrode start end clearing region, P1 positive electrode end clearing region, P1 negative electrode start end clearing region, and P1 negative electrode end clearing region. The P1 positive electrode start end clearing region and P1 positive electrode end clearing region are stepped with large and small ends, respectively. The small end is electrically connected to the positive cell region where it is located. The width of the small end is not greater than the width of the positive electrode region where it is located and does not exceed the location of the adjacent P1 wire groove. The width of the large end is not greater than the width of the sub-cell region and is not less than the width of the busbar to be set later.
[0010] Step 2: Continue fabricating a light-absorbing layer on the surface of the front electrode layer. Multiple P2 grooves are obtained by etching P2 lines on the light-absorbing layer. Each P2 groove is located close to its corresponding P1 groove. The bottom of each P2 groove exposes the front electrode layer. Then, the light-absorbing layers at the top and bottom ends corresponding to the positive and negative electrode regions are removed to expose the front electrode layer, resulting in the P2 positive electrode start-end clearing region, P2 positive electrode end-end clearing region, P2 negative electrode start-end clearing region, and P2 negative electrode end-end clearing region. The P2 positive electrode start-end clearing region and... The width of the edge clearing area at the termination end of the P2 positive electrode is consistent with the width of the larger ends of the corresponding edge clearing areas at the beginning and termination ends of the P1 positive electrode. The height of the edge clearing areas at the beginning and termination ends of the P2 positive electrode is less than the height of the corresponding edge clearing areas at the beginning and termination ends of the P1 positive electrode. The height of the edge clearing areas at the beginning and termination ends of the P2 positive electrode does not exceed the position of the smaller ends of the corresponding edge clearing areas at the beginning and termination ends of the P1 positive electrode.
[0011] Step 3: Continue fabricating a back electrode layer on the surface of the light-absorbing layer. Multiple P3 grooves are obtained by etching P3 lines on the back electrode layer. Each P3 groove is located close to its corresponding P2 groove, with the bottom of each P3 groove exposing the light-absorbing layer. Positive electrode busbar start-up area, positive electrode busbar end-up area, negative electrode busbar start-up area, and negative electrode busbar end-up area are respectively set at the upper and lower ends corresponding to the positive electrode region and the negative electrode region. The shapes of the positive electrode busbar start-up area and the positive electrode busbar end-up area are consistent with the shapes of their corresponding P1 positive electrode start-up edge clearing area and P1 positive electrode end-up edge clearing area, respectively. Each of the two structures is stepped, with its smaller end electrically connected to the positive cell region. The width of the smaller end is no greater than the width of the positive electrode region and does not exceed the location of the adjacent P3 slot. The width of the larger end is consistent with the width of the corresponding P1 positive electrode start-end clearing area and P1 positive electrode end clearing area. Except for retaining the back electrode layer of the positive electrode busbar start-end lead-out area and the positive electrode busbar end lead-out area, the back electrode layer in other positions in the edge area is removed to expose the light-absorbing layer to obtain the P3 clearing area. Busbars serving as positive and negative electrode lead-out ends are respectively set on the larger end areas of the positive electrode busbar start-end lead-out area and the positive electrode busbar end lead-out area.
[0012] Furthermore, the positive electrode extraction method further includes: in step one, the width of the starting end clearing area and the ending end clearing area of the P1 negative electrode are not greater than the width of the negative electrode area and do not exceed the location of the adjacent P1 slot; in step two, the width of the starting end clearing area and the ending end clearing area of the P2 negative electrode are not greater than the width of the negative electrode area and do not exceed the location of the adjacent P2 slot; in step three, the width of the starting end extraction area and the ending end extraction area of the negative electrode busbar are not greater than the width of the negative electrode area and do not exceed the location of the adjacent P3 slot.
[0013] Furthermore, the sum of the heights of the large and small ends of the positive electrode busbar starting and ending regions is less than the height of the edge region.
[0014] Furthermore, the height ratio of the large end to the small end of the positive electrode busbar starting area and the large end of the positive electrode busbar ending area is 1:1 to 1:4.
[0015] Furthermore, the processing methods for the P1, P2, and P3 etch lines are laser etching or mask etching, respectively.
[0016] Furthermore, the processing methods for the P1 edge clearing area, P2 edge clearing area, and busbar lead-out area are laser etching or mask plate processing, respectively.
[0017] Compared with existing technologies, the back electrode functional film, thin-film photovoltaic module, and positive electrode lead-out method of the present invention set a busbar lead-out area in the edge region of the back electrode layer. The busbar, serving as the positive and negative electrodes, is only connected to the back electrode layer within the busbar lead-out area, and is no longer directly connected to the back electrode layer within the battery area. This leads out the positive and negative electrodes without damaging the original thin-film photovoltaic module structure, and has no adverse effects on the encapsulation and testing of the thin-film photovoltaic module. It reduces the area of the positive electrode of the module without changing the size of the busbar, thereby increasing the power generation of the thin-film photovoltaic module. By changing the connection method between the back electrode layer and the busbar, the required conductivity between the positive and negative electrodes is achieved, avoiding the wear, scratches, and stress aging attenuation problems existing in conventional contact methods, while reducing the cost of the busbar by over 80%. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the planar structure of the back electrode layer of the back electrode functional film of the present invention;
[0019] Figure 2 This is a schematic diagram of the planar structure of the back electrode functional film of the present invention;
[0020] Figure 3 This is a schematic diagram illustrating the principle of step one of the positive electrode extraction method of the present invention;
[0021] Figure 4 This is a schematic diagram illustrating the principle of step two of the positive electrode extraction method of the present invention. Detailed Implementation
[0022] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.
[0023] Please refer to the following at the same time Figure 1 and Figure 2 As shown, the back electrode functional film of the present invention includes a substrate and a back electrode layer 1 disposed on the surface of the substrate.
[0024] The back electrode layer 1 includes a battery region 2 located in the middle and an edge region 3 located around the battery region 2. Multiple scribing grooves 4 are provided in the battery region 2 to divide the battery region 2 into multiple independent sub-battery regions 5. The leftmost sub-battery region 5 is the positive electrode region 6, and the rightmost sub-battery region 5 is the negative electrode region 7. The width of the positive electrode region 6 is smaller than the width of the negative electrode region 7.
[0025] At the upper and lower ends of the positive electrode region 6 and the negative electrode region 7, respectively, are provided a positive electrode busbar start-up area A, a positive electrode busbar end-up area B, a negative electrode busbar start-up area C, and a negative electrode busbar end-up area D. Each lead-up area is located within the edge region 3. The positive electrode busbar start-up area A and the positive electrode busbar end-up area B are stepped in shape with large and small ends, respectively. The small end m is electrically connected to the corresponding positive cell region 6. The width of the small end m is no greater than the width of the corresponding positive electrode region 6 and does not exceed the position of its adjacent scribed groove 4. The width of the large end n is no greater than the width of the sub-cell region 5. Except for retaining the back electrode layer 2 of the positive electrode busbar start-up area A and the positive electrode busbar end-up area B, the back electrode layer 2 at other locations within the edge region 4 is removed to expose the substrate.
[0026] Busbars 8, serving as the positive and negative electrode leads, are respectively installed in the large end n region of the positive electrode busbar starting area A and the positive electrode busbar ending area B. For example... Figure 2 As shown. The widths of the positive electrode busbar start-out area A and the positive electrode busbar end-out area B are not less than the width of busbar 8.
[0027] Specifically, the width of the starting end lead-out area C of the negative electrode busbar and the ending end lead-out area D of the negative electrode busbar are not greater than the width of the negative electrode area 7 and do not exceed the location of the adjacent scribing groove 4.
[0028] The sum of the heights of the large and small ends of the positive electrode busbar starting area A and the positive electrode busbar ending area B is less than the height of the edge area 3.
[0029] The height ratio of the large end to the small end of the positive electrode busbar starting area A and the large end to the small end of the positive electrode busbar ending area B is 1:1 to 1:4.
[0030] Please refer to the following at the same time Figure 1 , Figure 3 as well as Figure 4 As shown, the present invention also discloses a thin-film photovoltaic module, wherein a back electrode functional film as described above is disposed inside. The internal structure of the thin-film photovoltaic module includes a substrate (not shown in the figure), a front electrode layer 10, a light-absorbing layer 11 and a back electrode layer 1 disposed sequentially from bottom to top, wherein the back electrode layer 1 adopts the back electrode functional film as described above.
[0031] Please refer to the following at the same time Figures 1 to 4 As shown, the present invention also discloses a preferred embodiment of a method for drawing out a positive electrode, comprising the following steps:
[0032] like Figure 3As shown, in step one, the substrate with the pre-electrode layer 10 includes a battery region 12 in the middle and an edge region 13 around the battery region 12. Multiple P1 grooves 14 are formed on the battery region 12 by P1 scribe lines. The bottom of each P1 groove 14 exposes the substrate. The multiple parallel P1 grooves 14 divide the front electrode layer 10 of the battery region 12 into multiple independently separated sub-battery regions 15. The leftmost sub-battery region is the positive electrode region 16, and the rightmost sub-battery region is the negative electrode region 17. The width of the positive electrode region 16 is smaller than the width of the negative electrode region 17.
[0033] Next, the front electrode layers 10 at the top and bottom ends of the positive electrode region 16 and the negative electrode region 17 are removed to expose the substrate, resulting in the P1 positive electrode starting end clearing region E, the P1 positive electrode ending end clearing region F, the P1 negative electrode starting end clearing region G, and the P1 negative electrode ending end clearing region H. Each clearing region is located within the edge region 13. The P1 positive electrode starting end clearing region E and the P1 positive electrode ending end clearing region F are stepped in shape with large and small ends, respectively. The small end m′ is electrically connected to the positive battery region 16. The width of the small end m′ is not greater than the width of the positive electrode region 16 and does not exceed the location of the adjacent P1 slot 14 to prevent it from affecting the adjacent second sub-battery region and causing a short circuit. The width of the large end n′ is not greater than the width of the sub-battery region 15 and not less than the width of the busbar 18 to be installed later.
[0034] The purpose of removing the front electrode layer 10 located at the upper and lower ends of the positive electrode region 16 and the negative electrode region 17 is to prevent the subsequent back electrode layer 1 from connecting with it and causing a short circuit.
[0035] The battery region 12 and edge region 13 on the front electrode layer 10 correspond to and are the same as the battery region 2 and edge region 3 on the back electrode layer 1, respectively. The small end m′ and large end n′ of the P1 positive electrode start end clearing region E and the P1 positive electrode end clearing region F also correspond to and are the same as the small end m and large end n of the positive electrode busbar start end lead-out region A and the positive electrode busbar end lead-out region B, respectively.
[0036] like Figure 4As shown, in step two, a light-absorbing layer 11 is further prepared on the surface of the front electrode layer 10. Multiple P2 grooves 18 are obtained by scriber P2 lines on the light-absorbing layer 11. Each P2 groove 18 is located close to its corresponding P1 groove 14, and the bottom of each P2 groove 18 exposes the front electrode layer 10. Then, the light-absorbing layers 11 at the top and bottom ends corresponding to the positive electrode region 16 and the negative electrode region 17 are removed, exposing the front electrode layer 10, resulting in the P2 positive electrode start-end clearing region I, the P2 positive electrode end-end clearing region J, the P2 negative electrode start-end clearing region K, and the P2 negative electrode end-end clearing region L, respectively. Each clearing region is located within the edge region 13. Among them, the widths of the starting edge clearing region I and the ending edge clearing region J of the P2 positive electrode are consistent with the widths of the larger ends of the corresponding starting edge clearing region E and ending edge clearing region F of the P1 positive electrode, respectively. The heights of the starting edge clearing region I and the ending edge clearing region J of the P2 positive electrode are less than the heights of the corresponding starting edge clearing region E and ending edge clearing region F of the P1 positive electrode, respectively. The heights of the starting edge clearing region I and the ending edge clearing region J of the P2 positive electrode do not exceed the positions of the smaller ends m′ of the starting edge clearing region E and the ending edge clearing region F of the P1 positive electrode, respectively.
[0037] A light-absorbing layer 11 is retained in the edge clearing area I at the beginning end of the positive electrode P2 and the edge clearing area J at the end of the positive electrode P2, as well as the corresponding positive electrode area 16 and negative electrode area 17. The light-absorbing layer 11 is used to cover the front electrode layer 10 in step one to prevent short circuits between it and the subsequent back electrode layer 1.
[0038] like Figure 1 and Figure 2As shown, in step three, the back electrode layer 1 is further prepared on the surface of the light-absorbing layer 11. Multiple P3 grooves 9 are obtained by scriber P3 lines on the back electrode layer 1. Each P3 groove 9 is located close to its corresponding P2 groove 18, and the bottom of each P3 groove 9 exposes the light-absorbing layer 11. The multiple P3 grooves 19 divide the battery region 2 into multiple independently separated sub-battery regions 5. The leftmost sub-battery region 5 is the positive electrode region 6, and the rightmost sub-battery region 5 is the negative electrode region 7. The width of the positive electrode region 6 is smaller than the width of the negative electrode region 7. A positive electrode busbar start-up area A, a positive electrode busbar end-up area B, a negative electrode busbar start-up area C, and a negative electrode busbar end-up area D are respectively set at the upper and lower ends corresponding to the positive electrode region 6 and the negative electrode region 7. Each lead-up area is located within the edge region 3. The shapes of the positive electrode busbar starting end lead-out area A and the positive electrode busbar ending end lead-out area B are consistent with the shapes of the corresponding P1 positive electrode starting end clearing area E and P1 positive electrode ending end clearing area F, respectively. They are also stepped shapes with large and small ends. The small end m is electrically connected to the positive cell area 6 where it is located. The width of the small end m is not greater than the width of the positive electrode area 6 where it is located and does not exceed the position of the adjacent P3 slot 9. The width of the large end n is consistent with the width of the corresponding P1 positive electrode starting end clearing area E and P1 positive electrode ending end clearing area F, respectively.
[0039] Except for retaining the back electrode layer 1 at the starting end lead-out region A and the ending end lead-out region B of the positive electrode busbar, the back electrode layer 1 at other positions in the edge region 3 is removed to expose the light-absorbing layer 11, resulting in the P3 edge clearing region 19. Busbars 8, serving as positive and negative electrode lead-out ends, are respectively provided on the large end n regions of the starting end lead-out region A and the ending end lead-out region B of the positive electrode busbar.
[0040] Within the edge region 3 of the back electrode layer 1, a positive electrode busbar start-up area A, a positive electrode busbar end-up area B, a negative electrode busbar start-up area C, and a negative electrode busbar end-up area D are respectively set. The busbars 8, which serve as the positive and negative electrodes, are only connected to the back electrode layer 1 within the busbar lead-up area, and are no longer directly connected to the back electrode layer 1 within the battery region 2. This avoids direct contact between the back electrode layer 1 within the battery region 2 and the busbar 8, reducing the damage from friction and stress aging attenuation, while also reducing the cost of the busbar 8 by more than 80%.
[0041] The positive electrode lead-out method further includes: In step one, the width of the starting end cleaning area G and the ending end cleaning area H of the P1 negative electrode is not greater than the width of the negative electrode area 17 and does not exceed the location of the adjacent P1 slot 14. In step two, the width of the starting end cleaning area K and the ending end cleaning area L of the P2 negative electrode is not greater than the width of the negative electrode area 17 and does not exceed the location of the adjacent P2 slot 18. In step three, the width of the starting end lead-out area C and the ending end lead-out area D of the negative electrode busbar is not greater than the width of the negative electrode area 7 and does not exceed the location of the adjacent P3 slot 9.
[0042] The back electrode functional film as described above is obtained through the above method.
[0043] The sum of the heights of the large and small ends of the positive electrode busbar starting area A and the positive electrode busbar ending area B is less than the height of the edge area 3.
[0044] The height ratio of the larger and smaller ends of the positive electrode busbar starting area A and the positive electrode busbar ending area B is 1:1 to 1:4. In this embodiment, the height ratio of the larger and smaller ends of the positive electrode busbar starting area A and the positive electrode busbar ending area B is 1:3.
[0045] The design structure of the large and small ends of the positive electrode busbar starting end lead-out area A and the positive electrode busbar ending end lead-out area B makes the width of the busbar 8 no longer directly related to the width of the positive electrode of the thin-film photovoltaic module. This effectively reduces the positive electrode area and avoids the appearance defect of inconsistent busbar dimensions between the positive and negative electrodes. It also indirectly reduces the direct contact between the busbar 8 and the back electrode functional film, reducing damage and greatly reducing the material cost of the busbar. It is also aesthetically pleasing and easy to encapsulate.
[0046] The stepped areas of the positive electrode busbar start-up area A and the positive electrode busbar end-up area B can be adjusted according to requirements and have no adverse effect on the testing during thin-film photovoltaic module encapsulation.
[0047] By changing the lead-out structure on the positive electrode side of the back electrode functional film, the area of the positive electrode of the thin-film photovoltaic module is reduced without changing the size and lead-out method of the busbar at the positive and negative electrode leads, thus reducing the cost of the busbar by more than 80% and facilitating automated mass production.
[0048] The P1, P2, and P3 lines are processed by laser etching or by masking, respectively.
[0049] The processing methods for the P1 edge clearing area (including the P1 positive electrode start-end clearing area E, P1 positive electrode end-end clearing area F, P1 negative electrode start-end clearing area G, and P1 negative electrode end-end clearing area H), the P2 edge clearing area (including the P2 positive electrode start-end clearing area I, P2 positive electrode end-end clearing area J, P2 negative electrode start-end clearing area K, and P2 negative electrode end-end clearing area L), and the busbar lead-out area (including the positive electrode busbar lead-out area A, positive electrode busbar lead-out area B, negative electrode busbar start-end lead-out area C, and negative electrode busbar lead-out area D) are laser etching or masking, respectively.
[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A back electrode functional film, characterized in that, The system includes a substrate and a back electrode layer disposed on the surface of the substrate. The back electrode layer includes a battery region located in the middle and an edge region surrounding the battery region. Multiple scribe lines are formed within the battery region to divide it into multiple independently separated sub-battery regions. The leftmost sub-battery region is the positive electrode region, and the rightmost sub-battery region is the negative electrode region. The width of the positive electrode region is smaller than the width of the negative electrode region. A positive electrode busbar start-end lead-out area, a positive electrode busbar end-end lead-out area, a negative electrode busbar start-end lead-out area, and a negative electrode busbar end-end lead-out area are respectively provided at the upper and lower ends of the positive and negative electrode regions. The terminal lead-out areas are stepped in shape with large and small ends. The small end is electrically connected to the positive cell area it is located in. The width of the small end is not greater than the width of the positive electrode area it is located in and does not exceed the position of the adjacent scribing groove. The width of the large end is not greater than the width of the sub-cell area. Except for retaining the back electrode layer of the positive electrode busbar start-end lead-out area and the positive electrode busbar end-end lead-out area, the back electrode layer at other positions in the edge area is removed to expose the substrate. Busbars serving as positive and negative electrode lead-out ends are respectively set on the large end areas of the positive electrode busbar start-end lead-out area and the positive electrode busbar end-end lead-out area. The width of the positive electrode busbar start-end lead-out area and the positive electrode busbar end-end lead-out area is not less than the width of the busbar.
2. The back electrode functional film as described in claim 1, characterized in that, The width of the starting and ending lead-out areas of the negative electrode busbar shall not be greater than the width of the negative electrode area and shall not exceed the location of the adjacent scribing groove.
3. The back electrode functional film as described in claim 1, characterized in that, The sum of the heights of the large and small ends of the positive electrode busbar starting and ending regions is less than the height of the edge region; the ratio of the heights of the large and small ends of the positive electrode busbar starting and ending regions is 1:1 to 1:
4.
4. A thin-film photovoltaic module, characterized in that, It has a back electrode functional film as described in claim 1, 2 or 3 disposed inside it.
5. A method for drawing out a positive electrode, characterized in that, Includes the following steps: Step 1: The substrate with the pre-formed front electrode layer includes a battery region in the middle and an edge region around the battery region. Multiple P1 grooves are formed on the battery region using P1 scribe lines, with the bottom of each P1 groove exposed on the substrate. These parallel P1 grooves divide the front electrode layer of the battery region into multiple independent sub-battery regions. The leftmost sub-battery region is the positive electrode region, and the rightmost sub-battery region is the negative electrode region. The width of the positive electrode region is smaller than the width of the negative electrode region. Then, the top and bottom edges of the positive and negative electrode regions are removed respectively. The front electrode layer at the end is exposed to the substrate, and the starting edge clearing area of P1 positive electrode, the ending edge clearing area of P1 positive electrode, the starting edge clearing area of P1 negative electrode, and the ending edge clearing area of P1 negative electrode are obtained respectively. The shapes of the starting edge clearing area of P1 positive electrode and the ending edge clearing area of P1 positive electrode are stepped with large and small ends respectively. The small end is close to the battery area, and the width of the small end is not greater than the width of the positive electrode area and does not exceed the location of the adjacent P1 line groove. The width of the large end is not greater than the width of the sub-battery area and not less than the width of the busbar to be set later. Step 2: Continue fabricating a light-absorbing layer on the surface of the front electrode layer. Multiple P2 grooves are obtained by etching P2 lines on the light-absorbing layer. Each P2 groove is located close to its corresponding P1 groove. The bottom of each P2 groove exposes the front electrode layer. Then, the light-absorbing layers at the top and bottom ends corresponding to the positive and negative electrode regions are removed to expose the front electrode layer, resulting in the P2 positive electrode start-end clearing region, P2 positive electrode end-end clearing region, P2 negative electrode start-end clearing region, and P2 negative electrode end-end clearing region. The P2 positive electrode start-end clearing region and... The width of the edge clearing area at the termination end of the P2 positive electrode is consistent with the width of the larger ends of the corresponding edge clearing areas at the beginning and termination ends of the P1 positive electrode. The height of the edge clearing areas at the beginning and termination ends of the P2 positive electrode is less than the height of the corresponding edge clearing areas at the beginning and termination ends of the P1 positive electrode. The height of the edge clearing areas at the beginning and termination ends of the P2 positive electrode does not exceed the position of the smaller ends of the corresponding edge clearing areas at the beginning and termination ends of the P1 positive electrode. Step 3: Continue fabricating a back electrode layer on the surface of the light-absorbing layer. Multiple P3 grooves are obtained by etching P3 lines on the back electrode layer. Each P3 groove is located close to its corresponding P2 groove, with the bottom of each P3 groove exposing the light-absorbing layer. Positive electrode busbar start-up area, positive electrode busbar end-up area, negative electrode busbar start-up area, and negative electrode busbar end-up area are respectively set at the upper and lower ends corresponding to the positive electrode region and the negative electrode region. The shapes of the positive electrode busbar start-up area and the positive electrode busbar end-up area are consistent with the shapes of their corresponding P1 positive electrode start-up edge clearing area and P1 positive electrode end-up edge clearing area, respectively. Each of the two structures is stepped, with its smaller end electrically connected to the positive cell region. The width of the smaller end is no greater than the width of the positive electrode region and does not exceed the location of the adjacent P3 slot. The width of the larger end is consistent with the width of the corresponding P1 positive electrode start-end clearing area and P1 positive electrode end clearing area. Except for retaining the back electrode layer of the positive electrode busbar start-end lead-out area and the positive electrode busbar end lead-out area, the back electrode layer in other positions in the edge area is removed to expose the light-absorbing layer to obtain the P3 clearing area. Busbars serving as positive and negative electrode lead-out ends are respectively set on the larger end areas of the positive electrode busbar start-end lead-out area and the positive electrode busbar end lead-out area.
6. The method for leading out the positive electrode as described in claim 5, characterized in that, Also includes: In step one, the width of the starting edge cleaning area and the ending edge cleaning area of the P1 negative electrode are not greater than the width of the negative electrode area they are located in and do not exceed the location of the adjacent P1 slot; in step two, the width of the starting edge cleaning area and the ending edge cleaning area of the P2 negative electrode are not greater than the width of the negative electrode area they are located in and do not exceed the location of the adjacent P2 slot; in step three, the width of the starting end lead-out area and the ending end lead-out area of the negative electrode busbar are not greater than the width of the negative electrode area they are located in and do not exceed the location of the adjacent P3 slot.
7. The method for leading out the positive electrode as described in claim 5, characterized in that, The sum of the heights of the large and small ends of the positive electrode busbar starting and ending regions is less than the height of the edge region.
8. The method for leading out the positive electrode as described in claim 5, characterized in that, The height ratio of the large end to the small end of the positive electrode busbar starting area and the large end to the small end of the positive electrode busbar ending area is 1:1 to 1:
4.
9. The method for leading out the positive electrode as described in claim 5, characterized in that, The P1, P2, and P3 lines are processed by laser etching or by masking, respectively.
10. The method for leading out the positive electrode as described in claim 5, characterized in that, The processing methods for the P1 edge clearing area, P2 edge clearing area, and busbar lead-out area are laser etching or masking, respectively.