Crystalline silicon solar cell and surface selective texturing method thereof

Abstract

The invention discloses a crystalline silicon solar cell and a surface selective texturing method thereof, and the method comprises the steps: carrying out the irradiation of a laser with a specific wavelength on a grid line pattern region before texturing, enabling the region to form a larger pyramid structure after texturing, and enabling the texturing of the region to be more uniform, thereby achieving the selective texturing of the surface of the crystalline silicon solar cell. Therefore, the contact between the slurry and the cell is improved, and the ohmic contact performance of the crystalline silicon solar cell is improved. Meanwhile, the texture form of the non-laser area is not affected, a good light absorption effect is kept, and the cell piece has a better light trapping effect and ohmic contact at the same time; selective texturing on the surface of the crystalline silicon solar cell is realized by adopting laser with specific wavelength and selective texturing treatment; compared with a traditional texturing method, the method can more accurately control the structure and the performance of the surface of the crystalline silicon solar cell, so that the conversion efficiency of the crystalline silicon solar cell is improved.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a crystalline silicon solar cell and a method for surface selective texturing thereof. Background Art

[0002] At present, in the solar energy industry, as an important optoelectronic conversion device, the performance improvement of crystalline silicon solar cells is crucial for improving the utilization efficiency of solar energy. In the preparation process of crystalline silicon solar cells, surface texturing is a key link, which can effectively improve the light absorption efficiency of the cells, thereby enhancing the photoelectric conversion efficiency of the cells. However, the traditional texturing method uniformly treats the entire silicon wafer surface, making it difficult to achieve fine control of specific areas; with the continuous development of solar cell technology, the requirements for the performance of crystalline silicon cells are getting higher and higher, and the existing cell preparation methods are difficult to meet the need for differential treatment of different areas while improving the cell performance. Summary of the Invention

[0003] The main object of the present invention is to provide a method for surface selective texturing of a crystalline silicon solar cell, aiming to solve the problem that the existing cell preparation methods cannot perform fine control on specific areas and are difficult to perform differential treatment on different areas while improving the cell performance.

[0004] To achieve the above object, the present invention proposes a method for surface selective texturing of a crystalline silicon solar cell, and the method for surface selective texturing of the crystalline silicon solar cell includes: S1. Irradiate the cell wafer with a laser of a specific wavelength; S2. Perform selective texturing treatment on the cell wafer after laser irradiation; S3. Perform junction formation and passivation treatment on the cell wafer after selective texturing treatment; S4. Screen print the cell wafer to prepare a crystalline silicon solar cell.

[0005] In an embodiment, the laser irradiation method in step S1 is: Determine the position and size of the grid line pattern area of the cell wafer; Set the laser parameters of the laser device according to the position and size of the grid line pattern; Irradiate the grid line pattern area with a laser of a specific wavelength through the laser device.

[0006] In an embodiment, the selective texturing treatment method in step S2 is: Select a texturing additive; Set the texturing parameters of the texturing device according to the performance of the texturing additive; The texturing process is performed on the cell by the texturing equipment.

[0007] In one embodiment, the texturing additive is a high-texture texturing additive.

[0008] In one embodiment, the screen printing method in step S4 is as follows: Place the cell in the screen printing equipment, and capture the position and angle of the cell; Set the printing parameters of the screen printing equipment according to the size of the cell; Perform printing on the cell by the screen printing equipment.

[0009] The present invention also provides a crystalline silicon solar cell, which is obtained by the surface selective texturing method of the crystalline silicon solar cell described above.

[0010] The technical solution of the present invention irradiates the grid line pattern area with a laser of a specific wavelength before texturing, so that a larger pyramid structure is formed in this area after texturing, thereby improving the contact between the paste and the cell to improve the ohmic contact performance of the crystalline silicon solar cell; at the same time, the surface morphology of the non-laser area is not affected, maintaining a good light absorption effect, so that the cell has both better light trapping effect and ohmic contact; by using a laser of a specific wavelength and selective texturing treatment, selective texturing of the surface of the crystalline silicon solar cell is realized; compared with the traditional texturing method, this method can more precisely control the structure and performance of the surface of the crystalline silicon solar cell, thereby improving the conversion efficiency of the crystalline silicon solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic flow chart of the surface selective texturing method of the crystalline silicon solar cell of the present invention; Figure 2 It is a schematic structural diagram of the crystalline silicon solar cell of the present invention; In the figure: 1 - back electrode grid line, 2 - front electrode grid line, 3 - back film doping layer and passivation layer, 4 - front doping layer and passivation layer, 5 - Si substrate, 6 - non-laser area, 7 - laser selective texturing area. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0013] Accordingly, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0014] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not require further definition and explanation in subsequent drawings.

[0015] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is usually placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0016] In addition, the terms "first", "second", etc. are only used for descriptive distinction and should not be construed as indicating or implying relative importance.

[0017] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, terms such as "arrangement", "connection", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] During the preparation process of crystalline silicon solar cells, surface texturing can effectively improve the light absorption efficiency of the cells, thereby enhancing the photoelectric conversion efficiency of the cells. However, with the continuous development of solar cell technology, the existing texturing methods can only uniformly process the entire silicon wafer surface and are difficult to achieve fine control of specific regions, that is, the existing cell preparation methods are difficult to achieve differential treatment of different regions while improving the cell performance.

[0019] To solve the above problems, the present invention proposes a method for surface selective texturing of crystalline silicon solar cells. The following will be a detailed description of the specific embodiments of the present invention with reference to the drawings.

[0020] As Figure 1-2As shown, the method for surface selective texturing of a crystalline silicon solar cell includes the following steps: S1. Irradiate the cell with a laser of a specific wavelength; S2. Perform selective texturing on the cell irradiated with the laser; S3. Perform junction formation and passivation on the cell after selective texturing; S4. Screen-print the cell to fabricate a crystalline silicon solar cell.

[0021] In this embodiment, the cell in step S1 is a silicon wafer or a semi-finished cell of corresponding specifications and types selected according to different photovoltaic cell process requirements; the junction formation and passivation in step S3 are processes such as PN junction process and passivation process completed according to different photovoltaic cell process requirements.

[0022] The method for surface selective texturing of the crystalline silicon solar cell of the present invention irradiates the grid pattern area with a laser of a specific wavelength before texturing, so that a larger pyramid structure is formed in this area after texturing, thereby improving the contact between the paste and the cell to enhance the ohmic contact performance of the crystalline silicon solar cell; meanwhile, the surface texture morphology of the non-laser area is not affected, maintaining a good light absorption effect, enabling the cell to have better light trapping effect and ohmic contact at the same time; by using a laser of a specific wavelength and selective texturing treatment, selective texturing of the surface of the crystalline silicon solar cell is realized; compared with the traditional texturing method, this method can more precisely control the structure and performance of the surface of the crystalline silicon solar cell, thereby improving the conversion efficiency of the crystalline silicon solar cell.

[0023] In one embodiment, the laser irradiation method in step S1 is as follows: Determine the position and size of the grid pattern area of the cell; Set the laser parameters of the laser equipment according to the position and size of the grid pattern; Irradiate the grid pattern area with a laser of a specific wavelength through the laser equipment.

[0024] In this embodiment, the specific steps of laser irradiation include: First, determine the position and size of the grid line pattern area: Through precise lithography technology or other positioning methods, determine the position and size of the grid line pattern area on the solar cell according to the pre-designed pattern; Then, adjust the laser parameters: Adjust the laser parameters such as wavelength, power, scanning speed, focusing degree, etc. according to the material characteristics of the crystalline silicon solar cell and the requirements of the grid line pattern area to ensure that the laser can accurately irradiate the grid line pattern area and avoid affecting other areas; Finally, perform the laser irradiation operation: Use a laser device to irradiate the grid line pattern area of the solar cell. It should be noted that during the irradiation process, ensure the stability and uniformity of the laser to perform precise laser irradiation on the grid line pattern area and avoid local overheating or uneven irradiation. This embodiment uses a laser with a specific wavelength to irradiate the grid line pattern area to perform differential processing on different areas, realizing fine control of specific areas through selective texturing, so that the crystalline silicon solar cell simultaneously has better light trapping effect and ohmic contact performance.

[0025] In one embodiment, the selective texturing treatment method in step S2 is as follows: Select a texturing additive; Set the texturing parameters of the texturing equipment according to the performance of the texturing additive; Perform texturing treatment on the solar cell through the texturing equipment.

[0026] Furthermore, the texturing additive is a high-texture texturing additive.

[0027] In this embodiment, the specific steps of selective texturing treatment include: First, select a texturing additive: Select a suitable texturing additive according to the surface characteristics of the solar cell after laser irradiation and the texturing requirements. In this embodiment, a high-texture texturing additive is selected, which can form larger pyramid structures in the laser-irradiated area, is easily filled with paste, and the non-laser area maintains a good light-trapping velvet surface morphology, thereby improving the performance of the crystalline silicon solar cell; Then, adjust the texturing process parameters: Adjust the texturing process parameters such as temperature, time, solution concentration, etc. according to the material characteristics of the crystalline silicon solar cell and the performance of the texturing additive to ensure the stability and uniformity of the texturing process and obtain the best texturing effect; Finally, perform the texturing operation: Put the solar cell irradiated by the laser into the texturing equipment for texturing operation. It should be noted that during the texturing process, closely monitor the texturing effect and timely adjust the texturing process parameters to ensure the texturing quality.

[0028] In one embodiment, the screen printing method in step S4 is as follows: Place the solar cell in a screen printing equipment and capture the position and angle of the solar cell; Set the printing parameters of the screen printing equipment according to the size of the cell. Print the cell through the screen printing equipment.

[0029] In this embodiment, the specific steps of screen printing include: First, prepare the paste and the screen printing equipment: According to the performance requirements of the crystalline silicon solar cell and the requirements of the screen printing process, select appropriate paste and screen printing equipment to ensure that the quality and performance of the paste meet the requirements, and the accuracy and stability of the screen printing equipment are good; Then, place the cell processed by selective texturing and pre - processing steps on the screen printing equipment, and capture the position and angle of the cell through a high - precision camera to ensure the accuracy and stability of screen overprinting; Next, adjust the printing parameters: Adjust the printing parameters of the screen printing equipment such as pressure, speed, paste thickness, etc. according to the size and performance requirements of the cell to ensure the stability and uniformity of the printing process and obtain the best printing effect; Finally, perform the screen printing operation: Start the screen printing equipment and perform the screen printing operation. It should be noted that during the printing process, closely monitor the printing effect and timely adjust the printing parameters to ensure the printing quality.

[0030] The present invention also provides a crystalline silicon solar cell, which is obtained by the above - mentioned method for surface selective texturing of a crystalline silicon solar cell; The specific steps of the method for surface selective texturing of the crystalline silicon solar cell refer to the above - mentioned embodiment. Since this crystalline silicon solar cell adopts all the technical solutions of all the above - mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above - mentioned embodiments, which will not be elaborated here one by one.

[0031] In this embodiment, the crystalline silicon solar cell prepared by the method for surface selective texturing of a crystalline silicon solar cell includes a back electrode grid line 1, a front electrode grid line 2, a back film doping layer and a passivation layer 3, a front surface doping layer and a passivation layer 4, and an Si substrate 5. The un - laser - treated area 6 and the laser - selective texturing area 7 are as Figure 2 shown. The laser - selective texturing area 7 after being irradiated by laser with a specific wavelength has a pyramid structure to improve the contact between the paste and the silicon wafer. This crystalline silicon solar cell has both good light - trapping effect and ohmic contact performance.

[0032] In the present invention, the surface selective texturing method for crystalline silicon solar cells irradiates the grid pattern area with a laser of a specific wavelength before texturing, so that a larger pyramid structure is formed in this area after texturing, thereby improving the contact between the paste and the silicon wafer and enhancing the ohmic contact performance of the battery. At the same time, the surface morphology of the non-laser area is not affected, maintaining a good light absorption effect, enabling the battery chip to have better light trapping effect and ohmic contact simultaneously. Specifically, the surface selective texturing method for crystalline silicon solar cells in the present invention mainly starts from the following three aspects: Technological innovation: By using a laser of a specific wavelength and a texturing additive higher than the texture, selective texturing of the surface of the crystalline silicon cell is achieved. Compared with the traditional texturing method, the present invention can more precisely control the structure and performance of the battery surface, thereby improving the photoelectric conversion efficiency of the battery; Process innovation: Before texturing, the grid pattern area is irradiated with a laser, then selective texturing is carried out, and finally screen printing is performed. Compared with the traditional texturing method, the process of the present invention can effectively improve the printing contact performance of the battery chip, reduce the use of silver paste, and lower the production cost; Performance innovation: Through selective texturing, the crystalline silicon cell simultaneously has better light trapping effect and ohmic contact performance. Compared with the traditional texturing method, the present invention can improve the photoelectric conversion efficiency of the battery, reduce the production cost, and has higher performance advantages.

[0033] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for surface selective texturing of crystalline silicon solar cells, characterized in that, The method for surface selective texturing of the crystalline silicon solar cell comprises the following steps: S1. Irradiate the cell with a laser of a specific wavelength; S2. Perform selective texturing treatment on the cell irradiated with the laser; S3. Perform junction formation and passivation treatment on the cell after the selective texturing treatment; S4. Screen-print the cell to prepare the crystalline silicon solar cell.

2. The method for surface selective texturing of a crystalline silicon solar cell according to claim 1, wherein The laser irradiation method in the step S1 is as follows: Determine the position and size of the grid line pattern area of the cell; Set the laser parameters of the laser device according to the position and size of the grid line pattern; Irradiate the grid line pattern area with a laser of a specific wavelength through the laser device.

3. The method for surface selective texturing of a crystalline silicon solar cell according to claim 1, wherein, The selective texturing treatment method in the step S2 is as follows: Select a texturing additive; Set the texturing parameters of the texturing device according to the performance of the texturing additive; Perform texturing treatment on the cell through the texturing device.

4. The method for surface selective texturing of a crystalline silicon solar cell according to claim 3, wherein The texturing additive is a high-texture texturing additive.

5. The surface selective texturing method of the crystalline silicon solar cell according to claim 1, characterized in that The screen-printing method in the step S4 is as follows: Place the cell in the screen-printing device and capture the position and angle of the cell; Set the printing parameters of the screen-printing device according to the size of the cell; Print the cell through the screen-printing device.

6. A crystalline silicon solar cell, characterized in that, The crystalline silicon solar cell is obtained by the method for surface selective texturing of the crystalline silicon solar cell according to any one of claims 1-5.

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