Thin film photovoltaic module and method for improving photoelectric conversion efficiency of thin film photovoltaic module
By scribing lines on the front electrode layer and power generation layer of the thin-film photovoltaic module, sub-cell blocks are divided and abnormal sub-cells are screened. By controlling the scribing lines on the back electrode layer to avoid abnormal sub-cells, the problem of individual abnormal sub-cells affecting the electrical performance of the thin-film photovoltaic module is solved, and the photoelectric conversion efficiency is improved.
Patent Information
- Application Number
- CN202511083140.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-04
- Publication Date
- 2025-12-12
AI Technical Summary
In existing thin-film photovoltaic modules, some sub-cells experience abnormalities during the manufacturing process, affecting the electrical performance parameters of the entire module.
P1 and P2 lines are etched on the front electrode layer and power generation layer of the thin-film photovoltaic module to divide it into multiple independent sub-cell blocks. The current of these sub-cell blocks is tested and abnormal sub-cell blocks are screened out. When P3 lines are etched on the back electrode layer, the laser lines of the abnormal sub-cell blocks are skipped.
It improves the photoelectric conversion efficiency of thin-film photovoltaic modules, solves the power reduction problem caused by individual cell abnormalities, and enhances the overall performance of the modules.
Smart Images
Figure CN121126964A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electronic technology, and in particular to a thin-film photovoltaic module and a method for improving its photoelectric conversion efficiency. Background Technology
[0002] Solar energy is one of the main clean and renewable energy sources to replace fossil fuels in the future. Thin-film solar cells, as a promising and relatively mature type of solar cell, have advantages such as material savings, low cost, good absorption in weak light, and the ability to produce large-area cells. Laser scribing is an essential step in the production process of thin-film solar modules. Laser scribing serves two main purposes: to subdivide the continuous film layer into individual cells, and then to establish a series connection between these individual cells. The number of scribing lines varies depending on the manufacturer's design. There are typically three types of scribing: scribing on the front electrode (P1), scribing on the absorber layer (P2), and scribing on the back electrode (P3).
[0003] Currently, the mainstream connection technology for thin-film photovoltaic modules uses internal series connection. However, if some sub-cells in the series connection experience abnormalities during manufacturing, it can affect the electrical performance parameters of the entire thin-film photovoltaic module.
[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention
[0005] The main objective of this invention is to provide a thin-film photovoltaic module and a method for improving its photoelectric conversion efficiency, aiming to solve the technical problem in the prior art that when some sub-cells in a series-connected thin-film photovoltaic module are abnormal during the manufacturing process, the electrical performance parameters of the entire thin-film photovoltaic module will be affected.
[0006] To achieve the above objectives, the present invention provides a method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module, wherein the thin-film photovoltaic module comprises a glass layer, a front electrode layer, a power generation layer, and a back electrode layer stacked sequentially, and the method for improving the photoelectric conversion efficiency of the thin-film photovoltaic module includes:
[0007] P1 and P2 lines are sequentially etched on the front electrode layer and power generation layer of the thin-film photovoltaic module, dividing it into multiple phase-independent sub-cell blocks;
[0008] The light emitted by the light source is controlled to pass through multiple independent sub-cell blocks obtained by the P1 and P2 markings, so that the light is absorbed, converted into electronic energy, and generates current.
[0009] The current of multiple independent sub-cells is tested separately, and the current of each sub-cell is compared with the current threshold to screen out abnormal sub-cells whose current is less than the current threshold.
[0010] P3 lines are controlled to be made on the back electrode layer of the thin-film photovoltaic module, and abnormal sub-cells are ignored when P3 lines are made.
[0011] Preferably, in the method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module, the step of controlling the P3 marking on the back electrode layer of the thin-film photovoltaic module, and omitting the selected abnormal sub-cell blocks during the P3 marking, includes:
[0012] P3 lines are etched on the back electrode layer of the thin-film photovoltaic module, and the corresponding P3 laser lines above the screened abnormal sub-cells are removed.
[0013] Preferably, in the method for improving the photoelectric conversion efficiency of thin-film photovoltaic modules, the step of controlling the P3 etching on the back electrode layer of the thin-film photovoltaic module and canceling the corresponding P3 laser lines above the selected abnormal sub-cells includes:
[0014] Draw the corresponding process pattern based on the identified abnormal sub-cell blocks that need to be cancelled;
[0015] Adjust the laser parameter values corresponding to the drawn process pattern;
[0016] Based on the adjusted laser parameter values, P3 lines are etched on the back electrode layer of the thin-film photovoltaic module.
[0017] Preferably, in the method for improving the photoelectric conversion efficiency of thin-film photovoltaic modules, the step of testing the current of multiple independent sub-cell blocks and comparing the current of each sub-cell block with a current threshold to screen out abnormal sub-cell blocks with current less than the current threshold involves measuring the current of multiple independent sub-cell blocks using a multi-channel tester.
[0018] Preferably, in the method for improving the photoelectric conversion efficiency of thin-film photovoltaic modules, the multi-channel tester includes multiple sets of ammeters, the number of which matches the number of effective sub-cells in the thin-film photovoltaic module.
[0019] Preferably, in the method for improving the photoelectric conversion efficiency of thin-film photovoltaic modules, each ammeter of the multi-channel tester corresponds to one effective sub-cell block during testing;
[0020] In this configuration, one probe of the galvanometer contacts the front electrode layer of an effective sub-cell, while the other probe contacts the back electrode layer of the same effective sub-cell.
[0021] Preferably, in the method for improving the photoelectric conversion efficiency of thin-film photovoltaic modules, the step of testing the current of multiple independent sub-cell blocks and comparing the current of each sub-cell block with a current threshold to screen out abnormal sub-cell blocks with currents less than the current threshold includes:
[0022] The current of multiple independent effective sub-cells is tested separately, and the current of each effective sub-cell is compared with a current threshold to screen out abnormal sub-cells whose current is less than the current threshold.
[0023] Preferably, in the method for improving the photoelectric conversion efficiency of thin-film photovoltaic modules, in the step of controlling the light emitted by the light source to pass through multiple independent sub-cell blocks obtained by the P1 and P2 scribe lines, so that the light is absorbed, converted into electronic energy, and generates current, the light source is solar energy test simulation light.
[0024] Preferably, in the method for improving the photoelectric conversion efficiency of thin-film photovoltaic modules, in the step of controlling the light emitted by the light source to pass through multiple independent sub-cell blocks obtained by the P1 and P2 scribe lines, so that the light is absorbed, converted into electronic energy, and generates current, the light intensity of the light source is 1000 W / m. 2 The temperature is 25℃.
[0025] To achieve the above objectives, the present invention provides a thin-film photovoltaic module, wherein the thin-film photovoltaic module is adjusted using the above-described method for improving the photoelectric conversion efficiency of the thin-film photovoltaic module.
[0026] The present invention has at least the following beneficial effects:
[0027] The present invention provides a method for improving the photoelectric conversion efficiency of thin-film photovoltaic modules. P1 and P2 lines are sequentially etched on the front electrode layer and power generation layer of the thin-film photovoltaic module, dividing it into multiple independent sub-cell blocks. Light emitted from a light source is controlled to pass through these independent sub-cell blocks obtained through the P1 and P2 lines, causing the light to be absorbed and converted into electronic energy, generating current. The current of each independent sub-cell block is tested, and the current of each sub-cell block is compared with a current threshold to screen out abnormal sub-cell blocks whose current is less than the current threshold. P3 lines are etched on the back electrode layer of the thin-film photovoltaic module, and the screened abnormal sub-cell blocks are skipped during P3 etching. This solves the technical problem in the prior art where some sub-cells in a series-connected thin-film photovoltaic module, due to manufacturing abnormalities, affect the electrical performance parameters of the entire thin-film photovoltaic module.
[0028] Furthermore, the present invention solves the problem of a significant drop in power caused by current issues in individual battery cells. Attached Figure Description
[0029] Figure 1 A schematic diagram illustrating the method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module provided by the present invention;
[0030] Figure 2 This is a schematic diagram of the thin-film photovoltaic module and multi-channel tester of the present invention;
[0031] Figure 3 A schematic diagram of the internal series connection of the thin-film photovoltaic module provided by the present invention after the removal of an abnormal sub-cell block;
[0032] Figure 4 A schematic diagram illustrating the normal production of the scribing P3 pattern provided by the present invention;
[0033] Figure 5 for Figure 4 A schematic diagram of the P3 pattern after canceling the P3 laser line corresponding to an abnormal sub-cell.
[0034] 1-Glass layer, 2-Front electrode layer, 3-Power generation layer, 4-Back electrode layer, 5-Multi-channel tester.
[0035] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0036] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.
[0037] In this embodiment of the invention, the term "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following associated objects have an "or" relationship.
[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.
[0039] In this embodiment of the invention, the term "multiple" refers to two or more, and other quantifiers are similar.
[0040] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.
[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of the present invention to facilitate a better understanding of the invention. However, the technical solutions claimed in the present invention can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined with and referenced by each other without contradiction.
[0042] Currently, the mainstream connection technology for thin-film photovoltaic modules uses internal series connection. However, if some sub-cells in the series connection experience abnormalities during manufacturing, it can affect the electrical performance parameters of the entire thin-film photovoltaic module.
[0043] Taking a thin-film photovoltaic module with 194 sub-cells as an example, with each sub-cell having a working voltage of 0.9V and a working current of 0.68A, the power is 0.9 * 0.68 * 194 = 118.7W.
[0044] Suppose that when these 194 sub-cells are connected in series, one sub-cell has a manufacturing defect resulting in a current of 0.6A. The current of the 194 sub-cells connected in series will then be determined by the current of this sub-cell with the smallest current. Therefore, the total current of the entire module after series connection will be 0.6A, and the power will be 0.9 * 0.6 * 194 = 104.7W. This represents a power loss of 14W, which would lower the product's quality level, for example, by three grades.
[0045] To address the above problems, this invention provides a method for improving the photoelectric conversion efficiency of thin-film photovoltaic modules, such as... Figure 2 As shown, the thin-film photovoltaic module includes a glass layer 1, a front electrode layer 2, a power generation layer 3, and a back electrode layer 4, which are stacked sequentially. Figure 1 The diagram illustrates a method for improving the photoelectric conversion efficiency of thin-film photovoltaic modules provided by the present invention.
[0046] In step S100, P1 and P2 lines are sequentially etched on the front electrode layer 2 and power generation layer 3 of the thin-film photovoltaic module, dividing it into multiple independent sub-cell blocks.
[0047] Laser etching (P1, P2, P3) is a core step in achieving internal electrical connections and improving photoelectric conversion efficiency in thin-film solar cells. Its principle is based on the high energy density of lasers. By precisely removing thin-film layers in specific areas, conductive channels or isolation regions are formed, ultimately connecting multiple sub-cells in series to create a complete cell with a practical voltage. P1 etching involves creating parallel lines on the front electrode layer 2 of the thin-film photovoltaic module, dividing it into multiple independent strip-shaped regions to prepare for subsequent electrical connections with the power generation layer 3. P2 etching penetrates the power generation layer 3 and etches it down to the front electrode layer 2 below, creating an electrical connection between the power generation layer 3 of the current sub-cell and the front electrode layer 2 of the next sub-cell, thus achieving series connection of the sub-cells. P3 etching involves etching lines on the back electrode layer 4, dividing it into strip-shaped regions corresponding to the P1 etching lines. This ensures that the back electrode layer 4 of each sub-cell is only connected to its own power generation layer 3, and is connected in series with the front electrode layer 2 of the next sub-cell through the P2 etching lines, ultimately forming a complete series circuit.
[0048] Traditional thin-film photovoltaic (PV) module manufacturing processes involve performing the P3 laser process immediately after the PVD coating is completed. However, this invention, after sequentially etching the front electrode layer 2 and the power generation layer 3 with P1 and P2 lines, does not immediately perform the P3 etching. Instead, it first conducts performance parameter pre-tests on the multiple independent sub-cell blocks obtained through the P1 and P2 etching, and determines the specific pattern of the P3 etching based on the pre-test results.
[0049] In step S200, the light emitted by the light source passes through multiple independent sub-cell blocks obtained by marking lines P1 and P2, causing the light to be absorbed, converted into electronic energy, and generating an electric current. In some embodiments, the light emitted by the light source is a simulated solar energy test light, for example, 1000 W / m². 2 At 25℃, the light emitted by the light source passes through multiple independent sub-cell blocks obtained by the P1 and P2 scribe lines. The light is absorbed by the thin-film photovoltaic module and converted into electronic energy, causing electrons to migrate and flow in the material, generating an electric current.
[0050] It should be noted that, as Figure 2 As shown, in a thin-film photovoltaic module, the left and right side power generation layers 3 are ineffective power generation layers 3, and only the middle power generation layer 3 is an effective power generation layer 3. The effective power generation layer 3, together with its corresponding front electrode layer 2 and back electrode layer 4, forms an effective sub-cell block. Figure 2 For example, the left and right power generation layers 3 are ineffective power generation layers 3, and only the three power generation layers 3 in the middle are effective power generation layers 3. Therefore, the only effective sub-cell blocks are the three in the middle. That is, the second sub-cell block from the left is the first effective sub-cell block.
[0051] In step S300, the current of multiple independent sub-cell blocks is tested separately, and the current of each sub-cell block is compared with a current threshold to filter out abnormal sub-cell blocks whose current is less than the current threshold. It should be noted that during testing, multiple instruments for measuring current can be used to measure the current of multiple sub-cell blocks separately. In some embodiments, a multi-channel tester 5 can be used to measure the current of multiple independent sub-cell blocks. The multi-channel tester 5, by connecting multiple ammeters, can simultaneously monitor the current of multiple areas that need to be measured.
[0052] It is worth noting that the number of ammeters in the multi-channel tester 5 needs to match the number of sub-cell blocks. More specifically, the number of ammeters in the multi-channel tester 5 needs to match the number of effective sub-cell blocks. Figure 2 For example, Figure 2 The number of effective battery cells is 3, so the number of ammeters in the multichannel tester 5 can be three or more.
[0053] During testing, each ammeter in the multi-channel tester 5 corresponds to one effective sub-cell. One probe of the ammeter contacts the front electrode layer 2 of the effective sub-cell that has been cut off, and the other probe contacts the back electrode layer 4 of the effective sub-cell. In this way, the current value of this effective sub-cell can be obtained by the ammeter.
[0054] by Figure 2 For example, suppose Figure 2 There are 194 sub-cells, each with an operating voltage of 0.9V. The second active sub-cell from the left has a current of 0.6A, while the other active sub-cells have a current of 0.68A. Currently, the current value of the second active sub-cell is less than the current threshold, while the current values of the other active sub-cells are greater than or equal to the current threshold. Therefore, the second active sub-cell is considered an abnormal sub-cell. The P3 laser line corresponding to the second active sub-cell needs to be removed. The connection diagram after removal is shown below. Figure 3 As shown, this is equivalent to isolating the second effective sub-cell from the entire internal series system, so the power of the thin-film photovoltaic module is 0.9 * 0.68 * 193 = 118.1 W. This data is much better than including this abnormal sub-cell in the internal series system (the power of this abnormal sub-cell in the internal series system is 0.9 * 0.6 * 194 = 104.7 W).
[0055] Assuming that the thin-film photovoltaic module has 4 abnormal sub-cells that need to be isolated from the internal series system, then the power of the thin-film photovoltaic module is 0.9*0.68*190=116.2W, which is much better than 104.7W.
[0056] In step S400, P3 lines are etched on the back electrode layer 4 of the thin-film photovoltaic module, omitting the selected abnormal sub-cells during the P3 etch. After identifying the abnormal sub-cells to be cancelled, the corresponding P3 laser lines need to be cancelled. Specifically, based on the identified abnormal sub-cells to be cancelled, a corresponding process pattern is drawn; based on the drawn process pattern, the laser parameter values corresponding to the process pattern are adjusted; and based on the adjusted laser parameter values, P3 lines are etched on the back electrode layer 4 of the thin-film photovoltaic module.
[0057] The method for improving the photoelectric conversion efficiency of thin-film photovoltaic modules provided by this invention involves sequentially etching lines P1 and P2 on the front electrode layer 2 and power generation layer 3 of the thin-film photovoltaic module, dividing it into multiple independent sub-cell blocks; controlling the light emitted from the light source to pass through the multiple independent sub-cell blocks obtained by the P1 and P2 etching lines, so that the light is absorbed, converted into electronic energy, and generates current; testing the current of each of the multiple independent sub-cell blocks, comparing the current of each sub-cell block with a current threshold to screen out abnormal sub-cell blocks whose current is less than the current threshold; controlling the P3 etching on the back electrode layer 4 of the thin-film photovoltaic module, and skipping the screened abnormal sub-cell blocks when etching the P3 lines. This solves the technical problem in the prior art where some sub-cells in the series-connected thin-film photovoltaic module are affected by abnormalities in the manufacturing process, which affects the electrical performance parameters of the entire thin-film photovoltaic module.
[0058] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. Based on the embodiments of the present invention, those skilled in the art can make other variations or modifications without creative effort, and all such variations or modifications should fall within the scope of protection of the present invention.
Claims
1. A method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module, the thin-film photovoltaic module comprising a glass layer, a front electrode layer, a power generation layer, and a back electrode layer stacked sequentially, characterized in that, include: P1 and P2 lines are sequentially etched on the front electrode layer and power generation layer of the thin-film photovoltaic module, dividing it into multiple phase-independent sub-cell blocks; The light emitted by the light source is controlled to pass through multiple independent sub-cell blocks obtained by the P1 and P2 markings, so that the light is absorbed, converted into electronic energy, and generates current. The current of multiple independent sub-cells is tested separately, and the current of each sub-cell is compared with the current threshold to screen out abnormal sub-cells whose current is less than the current threshold. P3 lines are controlled to be made on the back electrode layer of the thin-film photovoltaic module, and abnormal sub-cells are ignored when P3 lines are made.
2. The method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module as described in claim 1, characterized in that, The step of controlling the P3 etching on the back electrode layer of the thin-film photovoltaic module, and ignoring the abnormal sub-cell blocks selected during the P3 etching process, includes: P3 lines are etched on the back electrode layer of the thin-film photovoltaic module, and the corresponding P3 laser lines above the screened abnormal sub-cells are removed.
3. The method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module as described in claim 2, characterized in that, The step of controlling the P3 etching on the back electrode layer of the thin-film photovoltaic module and canceling the corresponding P3 laser lines above the selected abnormal sub-cells includes: Draw the corresponding process pattern based on the identified abnormal sub-cell blocks that need to be cancelled; Adjust the laser parameter values corresponding to the drawn process pattern; Based on the adjusted laser parameter values, P3 lines are etched on the back electrode layer of the thin-film photovoltaic module.
4. The method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module as described in claim 1, characterized in that, In the step of testing the current of multiple independent sub-cells separately and comparing the current of each sub-cell with a current threshold to screen out abnormal sub-cells with current less than the current threshold, the current of multiple independent sub-cells is measured by a multi-channel tester.
5. The method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module as described in claim 4, characterized in that, The multi-channel tester includes multiple sets of ammeters, the number of which matches the number of effective sub-cells in the thin-film photovoltaic module.
6. The method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module as described in claim 5, characterized in that, During testing, each ammeter of the multi-channel tester corresponds to one effective sub-cell block. In this configuration, one probe of the galvanometer contacts the front electrode layer of an effective sub-cell, while the other probe contacts the back electrode layer of the same effective sub-cell.
7. The method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module as described in claim 4, characterized in that, The step of testing the current of multiple independent sub-cell blocks separately, and comparing the current of each sub-cell block with a current threshold to filter out abnormal sub-cell blocks with currents less than the current threshold includes: The current of multiple independent effective sub-cells is tested separately, and the current of each effective sub-cell is compared with a current threshold to screen out abnormal sub-cells whose current is less than the current threshold.
8. The method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module as described in claim 1, characterized in that, In the step of controlling the light source to emit light that passes through multiple independent sub-cell blocks obtained by the P1 and P2 markings, so that the light is absorbed, converted into electronic energy, and generates current, the light source is solar energy test simulation light.
9. The method for improving the photoelectric conversion efficiency of a thin-film photovoltaic module as described in claim 1, characterized in that, In the step where the light emitted by the controlled light source passes through multiple independent sub-cell blocks marked with lines P1 and P2, causing the light to be absorbed and converted into electronic energy to generate current, the light intensity of the light source is 1000 W / m². 2 The temperature is 25℃.
10. A thin-film photovoltaic module, characterized in that, The thin-film photovoltaic module is adjusted using the method for improving the photoelectric conversion efficiency of the thin-film photovoltaic module as described in any one of claims 1 to 9.