Production process of solar cell and solar cell
By using laser etching in the production process of solar cell cells, etching grooves are formed to isolate the PN junction conduction, the problem of leakage risk of battery cells is solved, the cost of chemicals and sewage treatment is reduced, and more environmentally friendly Production process.
Patent Information
- Application Number
- CN202411448764.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-17
- Publication Date
- 2025-02-07
AI Technical Summary
In the production process of conventional crystalline silicon TOPCon solar cells, there is a risk of leakage in the etching around the cell, and low-concentration alkali chemical etching methods increase the cost of chemicals and wastewater treatment.
Using laser etching technology, an etching groove is formed on the front side of the cell along the circumference of the cell to isolate the PN junction on the front and back sides of the cell to conduct the PN junction.
It effectively reduces the risk of battery cell leakage, reduces the cost of chemicals and sewage treatment, and reduces environmental pressure.
Smart Images
Figure CN119403262A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of solar cell production, and in particular to a solar cell production process and a solar cell. Background Art
[0002] In the production process of conventional crystalline silicon TOPCon solar cells, the four sides of the cell need to be etched to remove the PN junction around the cell to avoid leakage between the front and back sides.
[0003] Currently, etching around the battery cell is generally performed in the RCA cleaning process using a low concentration of alkali to selectively react silicon oxide and silicon. However, there is a risk of battery cell leakage in the RCA cleaning process. How to effectively reduce the risk of battery cell leakage has become an urgent problem to be solved. Summary of the invention
[0004] The purpose of the present application includes, for example, providing a production process for solar cells and solar cells, which can effectively reduce the risk of cell leakage.
[0005] The embodiments of the present application can be implemented as follows:
[0006] An embodiment of the present application provides a solar cell production process, which includes:
[0007] Pre-process the battery cells;
[0008] Screen printing of the battery cells;
[0009] The battery cell is laser etched to form an etched groove on the front side of the battery cell along the circumference of the battery cell.
[0010] Optionally, the distance between the etching groove and the edge of the battery cell is 0.1-0.4 mm, and the depth of the etching groove is 10-40 μm.
[0011] Optionally, the etched groove is a V-shaped groove, and the maximum width of the etched groove is 20-50 μm.
[0012] Optionally, the step of laser etching the cell to form an etching groove on the front side of the cell along the circumference of the cell includes:
[0013] In a first preset time, laser etching is performed on a single cell using a laser having a wavelength of 400-600 nm.
[0014] Optionally, the first preset time is 1.4-1.8s.
[0015] Optionally, the step of pre-processing the battery cell includes:
[0016] Clean and texture the battery cells;
[0017] Boron diffusion is performed on the battery cell;
[0018] Remove the borosilicate glass on the surface of the cell;
[0019] Depositing a polysilicon layer on the back of the cell;
[0020] Remove borosilicate glass and phosphosilicate glass from the surface of the cell;
[0021] Depositing an aluminum oxide layer on the front and / or back side of the cell;
[0022] Film layers are deposited on the front and back of the cell.
[0023] Optionally, the step of removing borosilicate glass and phosphosilicate glass on the surface of the cell includes:
[0024] During the second preset time, the borosilicate glass and phosphosilicate glass on the surface of the battery cell are removed by using an HF solution, wherein the volume fraction of the HF solution is 7.6%-8.0%.
[0025] Optionally, in the step of removing the borosilicate glass and phosphosilicate glass on the surface of the battery cell, the ambient temperature is set to room temperature.
[0026] Optionally, the second preset time is 100-200s.
[0027] The present application also provides a solar cell, which is manufactured by the solar cell production process.
[0028] The production process of solar cells and the beneficial effects of solar cells provided in the embodiments of the present application include, for example: in order to effectively reduce the risk of battery cell leakage, a production process of solar cells is designed. In the production process, the battery cells are first pre-treated, then the pre-treated battery cells are screen-printed, and finally the screen-printed battery cells are laser etched to form an etching groove on the front side of the battery cell along the circumference of the battery cell. The etching groove can effectively isolate the PN junction on the front and back sides of the battery cell from being turned on. Compared with the original method of chemical etching using low-concentration alkali, laser etching can effectively reduce the risk of battery cell leakage. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0030] Figure 1 This is a flow chart of steps S1-S3 in the production process of a solar cell according to an embodiment of the present application;
[0031] Figure 2 Flow chart of sub-steps S11 - S17 in the production process of a solar cell according to an embodiment of the present application. DETAILED DESCRIPTION
[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.
[0033] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0034] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0035] In the description of the present application, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, it is based on the orientation or position relationship shown in the drawings, or is the orientation or position relationship in which the product of the invention is usually placed when used. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.
[0036] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.
[0037] It should be noted that, in the absence of conflict, the features in the embodiments of the present application may be combined with each other.
[0038] The inventor of the present application has found that etching around the cell is currently generally performed in the RCA cleaning process using low-concentration alkali to selectively react silicon oxide and silicon, and there is a risk of cell leakage in the RCA cleaning process, and the chemical reaction etching using low-concentration alkali will increase the cost of chemicals on the one hand, and on the other hand, it will also lead to an increase in sewage treatment costs and environmental pressure. The embodiments of the present application provide a solar cell production process and solar cell, which can at least solve the above technical problems.
[0039] Please refer to Figure 1 , an embodiment of the present application provides a production process of a solar cell, comprising:
[0040] Step S1, pre-processing the battery cell.
[0041] Step S2: screen printing the battery cell.
[0042] Step S3: laser-etching the battery cell to form an etched groove on the front side of the battery cell along the circumference of the battery cell.
[0043] It should be noted that screen printing is to print metal paste on the front and back of the battery cell to form electrodes. Laser etching is performed by laser equipment. Compared with the method of chemical reaction etching using low-concentration alkali, it effectively reduces the risk of battery cell leakage, reduces chemical costs and sewage treatment costs, and reduces environmental pressure.
[0044] The shape of the battery cell can be determined according to the actual working conditions. For example, when the battery cell is rectangular, the process of laser etching the battery cell is to etch a rectangular ring-shaped etching groove on the front side of the battery cell; when the battery cell is round, the process of laser etching the battery cell is to etch a circular ring-shaped etching groove on the front side of the battery cell.
[0045] In this production process, the battery cells are first pretreated, then screen-printed, and finally laser-etched to form an etched groove on the front side of the battery cell along the circumference of the battery cell. The etched groove can effectively isolate the PN junction on the front and back sides of the battery cell from being turned on. Compared with the original method of chemical etching using low-concentration alkali, laser etching can effectively reduce the risk of battery leakage.
[0046] In an optional embodiment, the distance between the etching groove and the edge of the battery cell is 0.1-0.4 mm, and the depth of the etching groove is 10-40 μm.
[0047] The distance between the etching groove and the edge of the battery cell and the depth of the etching groove can be set on the laser equipment. After the setting is completed, the laser equipment can be turned on to perform laser etching according to the set distance between the etching groove and the edge of the battery cell and the depth of the etching groove.
[0048] Exemplarily, the distance between the etching groove and the edge of the battery cell can be selected to be 0.1mm, 0.2mm, 0.3mm or 0.4mm, and the depth of the etching groove can be selected to be 10μm, 20μm, 30μm or 40μm. It can be understood that the distance between the etching groove and the edge of the battery cell and the depth of the etching groove can be set within the above range according to actual working conditions.
[0049] In an optional embodiment, the etched groove is a V-shaped groove, and the maximum width of the etched groove is 20-50 μm.
[0050] It should be noted that laser etching of V-shaped grooves on the battery cell causes less damage to the battery cell, and the laser etching operation is also relatively easy; when the etched groove is a V-shaped groove, the maximum width of the etched groove refers to the width of the etched groove at the surface of the battery cell; the maximum width of the etched groove can also be set on the laser equipment. After the setting is completed, turning on the laser equipment can perform laser etching according to the set maximum width of the etched groove.
[0051] Exemplarily, the maximum width of the etched groove may be selected to be 20 μm, 30 μm, 40 μm or 50 μm. It is understandable that the maximum width of the etched groove may be set within the above range according to actual working conditions.
[0052] Further, step S3 includes:
[0053] In the first preset time, a single cell is laser-etched using a laser having a wavelength of 400-600 nm.
[0054] It should be noted that the wavelength of the laser in the laser device is set at 400-600nm. After the laser device is started, an etching groove is formed on the front side of the battery cell along the circumference of the battery cell. The time to complete the etching of a single battery cell is the first preset time. The first preset time can also be set in the laser device, so as to control the etching rate of the battery cell within a reasonable range.
[0055] Exemplarily, the wavelength of the laser in the laser device can be selected to be 400 nm, 500 nm or 600 nm. It can be understood that the wavelength of the laser in the laser device can be set within the above range according to actual working conditions.
[0056] The first preset time is 1.4-1.8s. It should be noted that controlling the etching time of a single cell within 1.4-1.8s can better ensure the etching rate of the cell on the one hand, and also ensure the quality of the cell on the other hand.
[0057] Exemplarily, the first preset time may be selected as 1.4s, 1.5s, 1.6s, 1.7s or 1.8s. It is understandable that the first preset time may be set within the above range according to actual working conditions.
[0058] Please refer to Figure 2 , step S1 comprises:
[0059] Sub-step S11, cleaning and texturing the battery cells.
[0060] Sub-step S12: performing boron diffusion on the battery cell.
[0061] Sub-step S13: removing the borosilicate glass on the surface of the cell.
[0062] Sub-step S14: depositing a polysilicon layer on the back side of the cell.
[0063] Sub-step S15, removing the borosilicate glass and phosphosilicate glass on the surface of the battery cell.
[0064] Sub-step S16: depositing an aluminum oxide layer on the front and / or back of the battery cell.
[0065] Sub-step S17: depositing film layers on the front and back sides of the battery cell.
[0066] It should be noted that cleaning and texturing is to remove the damage on the surface of the cell after cutting and form a pyramid structure to increase light absorption and improve the minority carrier lifetime; boron diffusion needs to be carried out at high temperature to form a PN junction on the cell, providing a basis for the electrical performance of the battery, and a borosilicate glass layer will be formed on the surface of the cell during the boron diffusion process. After the boron diffusion, the borosilicate glass on the surface of the cell needs to be removed. The process of removing the borosilicate glass can be done by alkali polishing.
[0067] In order to form a passivation contact structure, it is necessary to deposit a polysilicon layer on the back of the battery cell. Specifically, a layer of doped amorphous silicon film is first deposited on the back of the battery cell, and then high-temperature annealing is performed. The doped amorphous silicon film will change from an amorphous state to a polycrystalline state during the annealing process. The high-temperature annealing process can activate the passivation performance, passivate the interface between the polysilicon layer and the silicon wafer substrate, reduce the recombination of electron-hole pairs, and increase the open circuit voltage and short-circuit current of the battery.
[0068] Since the production process of the solar cell of the embodiment of the present application eliminates the original RCA cleaning process, the phosphosilicate glass and residual borosilicate glass are removed after the polysilicon layer is formed. The original process needs to use RCA slot equipment in the RCA process. The process time of the RCA slot equipment is about 45 minutes. The elimination of the RCA slot equipment can reduce the process time, increase the battery output, and reduce the probability of forming process complex centers, thereby improving efficiency. Moreover, in a low-concentration alkaline solution, the reaction ratio of silicon oxide and silicon is about 1:7, and there is a slight reaction to silicon oxide, which causes damage to the pyramid structure formed on the battery cell, thereby reducing the conversion efficiency. The production process of the embodiment of the present application can effectively reduce the damage to the pyramid structure formed on the battery cell, thereby improving the conversion efficiency.
[0069] After removing the phosphosilicate glass and the residual borosilicate glass, an aluminum oxide layer needs to be deposited on at least one of the front and back sides of the cell. The process of depositing the aluminum oxide layer can be completed by ALD equipment. After the aluminum oxide layer is deposited, a film layer needs to be deposited on the front and back sides of the cell to enhance the passivation effect of the cell. The completion of the film layer deposition means that the pretreatment of the cell is completed.
[0070] Further, sub-step S15 includes:
[0071] During the second preset time, the borosilicate glass and phosphosilicate glass on the surface of the battery cell are removed by using an HF solution, wherein the volume fraction of the HF solution is 7.6%-8.0%.
[0072] It should be noted that HF solution, i.e. hydrofluoric acid, is an aqueous solution of hydrogen fluoride gas, a colorless, fuming, corrosive liquid with a strong pungent odor. At the same time, hydrofluoric acid is a weak acid with extremely strong corrosiveness, which can strongly corrode metals, glass and silicon-containing objects. Therefore, the embodiments of the present application use HF solution to remove borosilicate glass and phosphosilicate glass on the surface of the battery cell.
[0073] The volume fraction of the HF solution may be 7.6%, 7.7%, 7.8%, 7.9% or 8.0%. It is understood that the volume fraction of the HF solution may be determined according to the proportion of each component in the mixed gas.
[0074] The second preset time is 100-200 seconds. It should be noted that the time for removing the borosilicate glass and phosphosilicate glass on the surface of the cell by the HF solution is controlled within 100-200 seconds, which can better remove the borosilicate glass and phosphosilicate glass on the surface of the cell and ensure the production efficiency of the cell.
[0075] Exemplarily, the second preset time may be selected as 100s, 110s, 120s, 130s, 140s, 150s, 160s, 170s, 180s, 190s or 200s. It will be appreciated that the second preset time may be set within the above range according to actual operating conditions.
[0076] In addition, in sub-step S15, the ambient temperature is set to room temperature, which is conducive to removing the borosilicate glass and phosphosilicate glass on the surface of the battery cell by the HF solution.
[0077] The technical effects of the solar cell production process provided by the embodiment of the present application at least include: adding a laser device after the screen printing process, and laser etching the cell by the laser device, which reduces the cost of chemicals and sewage treatment costs, reduces the environmental burden, and removes the RCA slot equipment required in the RCA process compared to the original process, thereby reducing the machine cost; the etching groove formed on the front of the cell by laser etching can effectively isolate the PN junction conduction on the front and back of the cell, and compared with the original method of chemical etching using a low concentration of alkali, laser etching can effectively reduce the risk of leakage of the cell; the etching time of a single cell is controlled within 1.4-1.8s, which can better ensure the etching rate of the cell on the one hand, and the quality of the cell on the other hand; the time for removing the borosilicate glass and phosphosilicate glass on the surface of the cell by HF solution is controlled within 100-200s, which can better remove the borosilicate glass and phosphosilicate glass on the surface of the cell on the one hand, and the production efficiency of the battery on the other hand.
[0078] The embodiments of the present application also provide a solar cell, which is manufactured by the above-mentioned solar cell production process. The technical effect of the solar cell is substantially the same as the technical effect of the above-mentioned solar cell production process, which will not be described in detail here.
[0079] In summary, the embodiments of the present application provide a production process for solar cells and solar cells. In the production process, the cell cells are first cleaned and textured, and then boron is diffused on the cell cells to form a PN junction on the cell cells to provide an electrical performance basis for the cell, and then the borosilicate glass on the surface of the cell cells is removed, and then a layer of doped amorphous silicon film is deposited on the back of the cell cells, followed by high-temperature annealing to form a polycrystalline silicon layer, and then the phosphosilicate glass and residual borosilicate glass on the surface of the cell cells are removed, and then an aluminum oxide layer is deposited on at least one of the front and back sides of the cell cells, and then a film layer is deposited on the front and back sides of the cell cells to enhance the passivation effect of the cell, and then the cell cells are screen-printed, and finally the screen-printed cell cells are laser etched to form an etching groove on the front side of the cell cells along the circumference of the cell cells that can effectively isolate the PN junctions on the front and back sides of the cell cells from being turned on. Compared with the original method of chemical etching using low-concentration alkali, laser etching can effectively reduce the risk of cell leakage.
[0080] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.
Claims
1. A production process for solar cells, characterized in that: include: Pre-process the battery cells; Screen printing of the battery cells; The battery cell is laser etched to form an etched groove on the front side of the battery cell along the circumference of the battery cell.
2. The production process of solar cells according to claim 1, characterized in that: The distance between the etching groove and the edge of the battery cell is 0.1-0.4 mm, and the depth of the etching groove is 10-40 μm.
3. The production process of solar cells according to claim 1, characterized in that: The etching groove is a V-shaped groove, and the maximum width of the etching groove is 20-50 μm.
4. The production process of solar cells according to claim 1, characterized in that: The step of laser etching the cell to form an etching groove on the front side of the cell along the circumference of the cell comprises: In a first preset time, laser etching is performed on a single cell using a laser having a wavelength of 400-600 nm.
5. The production process of solar cells according to claim 4, characterized in that: The first preset time is 1.4-1.8s.
6. The production process of solar cells according to claim 1, characterized in that: The steps for pre-processing the battery cells include: Clean and texture the battery cells; Boron diffusion is performed on the battery cell; Remove the borosilicate glass on the surface of the cell; Depositing a polysilicon layer on the back of the cell; Remove borosilicate glass and phosphosilicate glass from the surface of the cell; Depositing an aluminum oxide layer on the front and / or back side of the cell; Film layers are deposited on the front and back of the cell.
7. The production process of solar cells according to claim 6, characterized in that: The steps of removing borosilicate glass and phosphosilicate glass from the surface of the cell include: During the second preset time, the borosilicate glass and phosphosilicate glass on the surface of the battery cell are removed by using an HF solution, wherein the volume fraction of the HF solution is 7.6%-8.0%.
8. The production process of solar cells according to claim 7, characterized in that: In the step of removing the borosilicate glass and phosphosilicate glass on the surface of the battery cell, the ambient temperature is set to room temperature.
9. The production process of solar cells according to claim 7, characterized in that: The second preset time is 100-200s.
10. A solar cell, characterized in that: The solar cell is manufactured by the production process of any one of claims 1 to 9.