Electrode preparation method and equipment for silicon heterojunction battery

Abstract

The present application provides a method and equipment for preparing electrodes of silicon heterojunction batteries, which relates to the field of semiconductor or photovoltaic material processing and solves the technical problem of high cost of preparing electrodes for silicon-based heterojunction batteries. The method for preparing electrodes of silicon heterojunction batteries includes: providing a substrate; using a screen printing template to print a mixed slurry of catalytically active factors and polymer slurry on the substrate to form a printed layer, the printed layer having a printed area and a hollowed area; using a laser to irradiate the printed layer to obtain a substrate with activated catalytically active factors; immersing the substrate with the activated catalytically active factors in a chemical plating reagent to deposit a metal layer on the sides of the printed layer and the substrate; etching the metal layer located on the printed layer and the metal layer located on the sides of the substrate by equal amounts to obtain a substrate with grid lines. The use of this method to prepare electrodes for silicon heterojunction batteries does not require the use of electroplating equipment to electroplate grid lines, thereby reducing the preparation cost of battery cells.

Description

Technical Field

[0001] The present application relates to the field of semiconductor or photovoltaic material processing, and specifically to a method and equipment for preparing electrodes of a silicon heterojunction battery. Background Art

[0002] In traditional processes, silicon-based heterojunction cells are prepared based on low-temperature processes, and expensive low-temperature silver paste is required to prepare the electrodes of the cell, resulting in high manufacturing costs for silicon-based heterojunction cells. In addition, the resistivity of low-temperature silver paste is high, and the photoelectric conversion efficiency of the electrodes prepared using this material is low.

[0003] In order to solve this problem, the industry has begun to use copper electroplating technology to replace the traditional low-temperature silver paste screen printing solution when preparing electrode grid lines. The copper grid lines have a low resistivity, which can improve the photovoltaic conversion efficiency of the cell. In addition, the use of copper electrodes instead of traditional low-temperature silver paste electrodes can reduce the material cost of the silver paste. When using the copper electroplating process to prepare electrode grid lines, a physical vapor deposition device is first used to prefabricate a copper seed layer on the transparent conductive film of the silicon heterojunction cell. Then, a dry film exposure and development is used on the copper seed layer to form a pattern. After that, the copper grid lines are electroplated. Finally, the dry film and copper seed layer are removed by etching and cleaning to complete the copper metallization process. However, since the graphic process (i.e., the process of dry film exposure and development to form a pattern) requires the use of high-precision expensive photolithography equipment and expensive photoresist, and the electroplating process of the copper grid lines requires the use of expensive electroplating equipment, the cost of preparing cell electrodes using the copper electroplating process is high. Therefore, how to reduce the cost of electrode preparation for silicon-based heterojunction cells has become an urgent problem to be solved. Summary of the Invention

[0004] In order to solve the above technical problems, the present application is proposed. The embodiments of the present application provide a method and device for preparing electrodes of a silicon heterojunction battery.

[0005] In a first aspect, an embodiment of the present application provides a method for preparing an electrode of a silicon heterojunction battery, comprising: providing a substrate, wherein the substrate has a silicon wafer; printing a mixed slurry of a catalytically active factor and a polymer slurry on the substrate using a screen printing template to form a printed layer, the printed layer having a printed area and a hollow area; irradiating the printed layer with a laser to volatilize the polymer slurry in the printed area and activate the catalytically active factor, thereby obtaining a substrate having activated catalytically active factors; immersing the substrate having the activated catalytically active factors in a chemical plating reagent to deposit a metal layer on the printed layer and the side of the substrate, wherein the thickness of the metal layer located in the printed area is greater than the thickness of the metal layer located in the hollow area, and the thickness of the metal layer located in the printed area is greater than the thickness of the metal layer located on the side of the substrate; etching the metal layer located in the printed layer and the metal layer located on the side of the substrate by equal amounts to remove the metal layer located in the hollow area and the metal layer located on the side of the substrate, so that the metal layer in the printed area forms a grid line, thereby obtaining a substrate having a grid line.

[0006] In some embodiments, the substrate further has a transparent conductive layer and a protective layer. Providing the substrate includes: providing a substrate, wherein the substrate has a silicon wafer and a transparent conductive layer; and preparing a protective layer on the transparent conductive layer.

[0007] In some embodiments, the protective layer includes an indium antimony oxide layer; wherein preparing the protective layer on the transparent conductive layer includes: depositing the indium antimony oxide layer on the transparent conductive layer by physical vapor deposition.

[0008] In some embodiments, after obtaining the substrate having the activated catalytically active factors, the method further includes: removing residual polymer slurry to retain the activated catalytically active factors.

[0009] In some embodiments, the metal layer includes a copper layer and a tin layer; wherein depositing the metal layer on the sides of the printed layer and the substrate includes: depositing a copper layer on the sides of the printed layer and the substrate; and depositing a tin layer on the copper layer.

[0010] In some embodiments, etching the metal layer located on the printed layer and the metal layer located on the side of the substrate by equal amounts includes: etching the metal layer located on the printed layer and the metal layer located on the side of the substrate by equal amounts using an acidic reagent to remove the metal layer located in the hollow area and the metal layer located on the side of the substrate.

[0011] In some embodiments, the silicon wafer has a first side and a second side opposite to each other; wherein the substrate has two transparent conductive layers, the first transparent conductive layer is located on the first side of the silicon wafer, and the second transparent conductive layer is located on the second side of the silicon wafer.

[0012] In some embodiments, the polymer slurry includes acrylonitrile-butadiene-styrene copolymer, and / or the catalytic active factor includes copper hydroxyphosphate.

[0013] In some embodiments, the groove width of the screen printing template ranges from 10 microns to 30 microns.

[0014] In a second aspect, an embodiment of the present application provides an electrode preparation device for a silicon heterojunction battery, comprising: a preparation device for preparing a protective layer on a pre-provided substrate to obtain a substrate, wherein the substrate has a silicon wafer and a transparent conductive layer; a printing device for printing a mixed slurry of a catalytically active factor and a polymer slurry on the substrate using a screen printing template to form a printed layer, wherein the printed layer has a printed area and a hollow area; a laser device for irradiating the printed layer with a laser to volatilize the polymer slurry in the printed area and activate the catalytically active factor to obtain a substrate having the activated catalytically active factor A deposition device is used to immerse the substrate having the activated catalytic activity factor in a chemical plating agent to deposit a metal layer on the printing layer and the side of the substrate, wherein the thickness of the metal layer located in the printing area is greater than the thickness of the metal layer located in the hollow area, and the thickness of the metal layer located in the printing area is greater than the thickness of the metal layer located on the side of the substrate; a removal device is used to etch the metal layer located in the printing layer and the metal layer located on the side of the substrate equally to remove the metal layer located in the hollow area and the metal layer located on the side of the substrate, so that the metal layer in the printing area forms a grid line, thereby obtaining a substrate with a grid line.

[0015] The electrode preparation method and equipment for silicon heterojunction cells proposed in the embodiments of the present application, firstly, because there is no need to use electroplating equipment to electroplate the grid lines, the preparation cost of the cell is reduced. Secondly, the hollow area can be shielded by using a screen printing template. When the printed layer is irradiated with a laser, there is no need to use high-precision expensive photolithography equipment. Low-precision laser equipment can be used, which reduces the preparation cost of the cell. In addition, since the mixed slurry does not need to be cured, a polymer slurry with a lower viscosity can be used, and then a screen printing template with an extremely narrow line width can be used to make the catalytic active factors adhere to the substrate with a smaller spacing, so that in the subsequent steps, extremely fine grid lines can be prepared based on the catalytic active factors with a smaller spacing, thereby improving the photovoltaic conversion efficiency of the cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other purposes, features, and advantages of the present application will become more apparent through a more detailed description of the embodiments of the present application in conjunction with the accompanying drawings. The accompanying drawings are intended to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the drawings, the same reference numerals generally represent the same components or steps.

[0017] Figure 1Shown is a schematic flow chart of a method for preparing an electrode for a silicon heterojunction battery provided by an exemplary embodiment of the present application.

[0018] Figure 2 Shown is a schematic diagram of a substrate provided by an exemplary embodiment of the present application.

[0019] Figure 3 FIG. 1 is a schematic diagram of printing paste on a first side of a substrate using a screen printing template according to an exemplary embodiment of the present application.

[0020] Figure 4 FIG. 1 is a schematic diagram of irradiating a printing layer on a first side of a substrate with a laser according to an exemplary embodiment of the present application.

[0021] Figure 5 FIG. 1 is a schematic diagram showing an exemplary embodiment of the present application providing a substrate with activated catalytically active factors on the first side.

[0022] Figure 6 FIG. 1 is a schematic diagram of printing paste on the second side of a substrate using a screen printing template according to an exemplary embodiment of the present application.

[0023] Figure 7 FIG. 1 is a schematic diagram of irradiating a printed layer on the second side of a substrate with a laser according to an exemplary embodiment of the present application.

[0024] Figure 8 Shown is a schematic diagram of activated catalytic activity factors on both sides of a substrate provided by an exemplary embodiment of the present application.

[0025] Figure 9 Shown is a schematic diagram of a substrate with a copper layer provided by an exemplary embodiment of the present application.

[0026] Figure 10 Shown is a schematic diagram of a substrate with a tin layer provided by an exemplary embodiment of the present application.

[0027] Figure 11 FIG. 1 is a schematic diagram of a substrate with gate lines provided by an exemplary embodiment of the present application.

[0028] Figure 12 Shown is a schematic flow chart of a method for preparing an electrode for a silicon heterojunction battery provided by another exemplary embodiment of the present application.

[0029] Figure 13 Shown is a schematic structural diagram of an electrode preparation device for a silicon heterojunction battery provided by an exemplary embodiment of the present application.

[0030] Reference numerals:

[0031] 100. Substrate; 101. Silicon wafer; 102. Protective layer; 103. Printing layer; 104. Catalytic activity factor; 105. Metal layer; 1051. Copper layer; 1052. Tin layer; 200. Screen printing template; 500. Electrode preparation equipment for silicon heterojunction battery; 501. Preparation device; 502. Printing device; 503. Laser device; 504. Deposition device; 505. Removal device. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0033] Application Overview

[0034] Photovoltaic power generation is a technology that uses the photovoltaic effect at semiconductor interfaces to directly convert sunlight into electricity. The key component of this technology is the solar cell, which is connected in series and then encapsulated to form a large-area solar cell module. With economic development and social progress, people are placing ever-higher demands on energy, and the search for new energy sources has become a pressing issue. Due to its sustainability, pollution-free nature, widespread availability, and low cost, solar photovoltaic power generation has become the second largest energy source after traditional coal-fired power generation. Every 1% increase in photovoltaic power generation efficiency translates to a 7% decrease in cost. Therefore, improving the efficiency of photovoltaic cells and reducing the cost per kilowatt-hour are key technical goals for photovoltaic power generation. Silicon-based heterojunction solar cells, with their high efficiency, simple production process, and high stability, are gaining increasing attention within the industry.

[0035] In traditional processes, silicon-based heterojunction cells are prepared based on low-temperature processes, requiring the use of expensive low-temperature silver paste to prepare the electrodes of the cell. This results in high manufacturing costs for silicon-based heterojunction cells, and the resistivity of low-temperature silver paste is high, resulting in low photoelectric conversion efficiency of electrodes prepared using this material. In addition, current silicon-based heterojunction cells generally use a preparation method that screen-prints low-temperature silver paste and then sinters it at low temperatures to form metal electrodes. The silver electrodes prepared by screen printing have a small aspect ratio, resulting in a large light-shielding area for the cell, hindering further improvement in the photoelectric conversion efficiency of the cell. How to reduce the cost of preparing electrodes for silicon-based heterojunction cells and improve the photovoltaic conversion efficiency of silicon-based heterojunction cells is the key to the scale-up of silicon-based heterojunction cells.

[0036] In order to solve this problem, the industry has begun to use copper electroplating technology to replace the traditional low-temperature silver paste screen printing solution when preparing electrode grid lines. The copper grid lines have a low resistivity, which can improve the photovoltaic conversion efficiency of the cell. In addition, the use of copper electrodes instead of traditional low-temperature silver paste electrodes can reduce the material cost of the silver paste. When using the copper electroplating process to prepare electrode grid lines, a physical vapor deposition device is first used to prefabricate a copper seed layer on the transparent conductive film of the silicon heterojunction cell. Then, a dry film exposure and development is used on the copper seed layer to form a pattern. After that, the copper grid lines are electroplated. Finally, the dry film and copper seed layer are removed by etching and cleaning to complete the copper metallization process. However, since the patterning step (i.e., the step of dry film exposure and development to form a pattern) requires the use of expensive photolithography equipment with high precision and expensive photoresist, the electroplating step of the copper grid lines requires the use of expensive electroplating equipment, resulting in a high cost for preparing cell electrodes using the copper electroplating process. In addition, in the copper electroplating step, conductive needles are required to connect the cell for charge transfer. Metal deposition is easily present on the surface of the conductive needles, thereby damaging the cell.

[0037] In view of this, the present application proposes a method and equipment for preparing electrodes of silicon heterojunction batteries, first, providing a substrate, wherein the substrate has a silicon wafer; secondly, using a screen printing template to print a mixed slurry of a catalytically active factor and a polymer slurry on the substrate to form a printed layer, the printed layer having a printed area and a hollow area; then using a laser to irradiate the printed layer to volatilize the polymer slurry in the printed area and activate the catalytically active factor, thereby obtaining a substrate having activated catalytically active factors; then, immersing the substrate having the activated catalytically active factor in a chemical plating reagent to deposit a metal layer on the printed layer and the side of the substrate, wherein the thickness of the metal layer located in the printed area is greater than the thickness of the metal layer located in the hollow area, and the thickness of the metal layer located in the printed area is greater than the thickness of the metal layer located on the side of the substrate; finally, by etching the metal layer located in the printed layer and the metal layer located on the side of the substrate by equal amounts, the metal layer located in the hollow area and the metal layer located on the side of the substrate are removed, so that the metal layer in the printed area forms a grid line, thereby obtaining a substrate with extremely fine grid lines.

[0038] Using this method, firstly, since there is no need to use electroplating equipment to electroplate the grid lines, the preparation cost of the cell is reduced. Secondly, the hollow area can be shielded by using a screen printing template. When using a laser to irradiate the printed layer, there is no need to use high-precision and expensive photolithography equipment. Low-precision laser equipment can be used, which reduces the preparation cost of the cell. In addition, since the mixed slurry does not need to be cured, a polymer slurry with a lower viscosity can be used, and then a screen printing template with an extremely narrow line width can be used to make the catalytic active factors adhere to the substrate with a smaller spacing. In the subsequent steps, extremely fine grid lines can be prepared based on the catalytic active factors with a smaller spacing, thereby improving the photovoltaic conversion efficiency of the cell.

[0039] Exemplary Methods

[0040] Figure 1 FIG2 is a schematic flow chart of a method for preparing an electrode of a silicon heterojunction battery provided by an exemplary embodiment of the present application; Figure 2 Shown is a schematic diagram of a substrate provided by an exemplary embodiment of the present application; Figure 3 FIG2 is a schematic diagram showing a method of printing paste on a first side of a substrate using a screen printing template according to an exemplary embodiment of the present application; Figure 4 FIG2 is a schematic diagram showing a method of irradiating a printed layer on a first side of a substrate with a laser according to an exemplary embodiment of the present application; Figure 5 FIG2 is a schematic diagram showing a substrate provided by an exemplary embodiment of the present application having a first side with activated catalytic active factors; Figure 6 FIG2 is a schematic diagram showing a method of printing paste on the second side of a substrate using a screen printing template according to an exemplary embodiment of the present application; Figure 7 FIG2 is a schematic diagram showing a method of irradiating a printed layer on a second side of a substrate with a laser according to an exemplary embodiment of the present application; Figure 8 FIG2 is a schematic diagram showing a substrate provided by an exemplary embodiment of the present application having activated catalytic active factors on both sides; Figure 9 FIG2 is a schematic diagram of a substrate having a copper layer provided by an exemplary embodiment of the present application; Figure 10 FIG2 is a schematic diagram of a substrate having a tin layer provided by an exemplary embodiment of the present application; Figure 11 FIG. 1 is a schematic diagram of a substrate with gate lines provided by an exemplary embodiment of the present application.

[0041] like Figures 1 to 11 As shown, the method for preparing an electrode of a silicon heterojunction battery provided in an embodiment of the present application includes the following steps 301 to 305.

[0042] Step 301: Provide a substrate.

[0043] The substrate 100 includes a silicon wafer 101 .

[0044] In some embodiments, as Figure 2As shown, the substrate 100 also has a transparent conductive layer (not shown) and a protective layer 102. When providing the substrate 100, a substrate can be provided first, wherein the substrate has a silicon wafer 101 and a transparent conductive layer; and then the protective layer 102 is prepared on the transparent conductive layer. Among them, the transparent conductive layer can be exemplarily an indium tin oxide (ITO) transparent conductive layer. By providing a transparent conductive layer, the conductivity of the surface of the silicon wafer 101 can be improved, so that the charge inside the silicon wafer 101 can be transferred to the gate line through the transparent conductive layer. The protective layer 102 is used to protect the transparent conductive layer when etching the metal layer 105 in step 305 to prevent the transparent conductive layer from being etched. For example, if an acidic reagent is used to etch the metal layer 105 in step 305, the protective layer 102 can have good acid resistance.

[0045] In some embodiments, if gate lines are prepared on both sides of the substrate 100, the silicon wafer 101 has a first side and a second side opposite to each other; wherein the substrate 100 has two transparent conductive layers, the first transparent conductive layer is located on the first side of the silicon wafer 101, and the second transparent conductive layer is located on the second side of the silicon wafer 101.

[0046] In some embodiments, protective layer 102 includes an indium antimony oxide (ATO) layer. When forming protective layer 102 on the transparent conductive layer, the indium antimony oxide layer can be deposited on the transparent conductive layer via physical vapor deposition (PVD). Specifically, indium antimony oxide is a mixture of indium oxide and antimony oxide. It exhibits excellent electrical conductivity and acid resistance, is transparent to visible light, and is a novel semiconductor material. When forming protective layer 102, the substrate can be placed in a PVD apparatus to deposit the indium antimony oxide layer.

[0047] In other embodiments, the indium antimony oxide layer may be deposited by electron beam evaporation or sputtering deposition.

[0048] In some embodiments, the thickness of the indium antimony oxide is preferably 2 nm to 10 nm.

[0049] In some embodiments, as Figure 2 As shown, if gate lines are formed on both sides of the substrate 100 , then in step 301 , a protective layer 102 is formed on both transparent conductive layers of the substrate 100 .

[0050] Step 302: Printing a mixed slurry of catalytic active factors and polymer slurry on a substrate using a screen printing template to form a printing layer, wherein the printing layer has a printing area and a hollow area.

[0051] The screen printing template 200 and the printing layer 103 are exemplarily shown as follows: Figure 3 As shown. The printed area is the area on the surface of the substrate 100 covered by the mixed slurry. The hollow area is covered by the screen printing template 200 and is therefore the area on the surface of the substrate 100 not covered by the mixed slurry. In addition, the side edges of the substrate 100 are also not covered by the mixed slurry. Specifically, the screen printing template 200 can be placed on the substrate 100 and aligned so that the groove area of ​​the screen printing template 200 overlaps with the area on the substrate 100 where the grid lines are to be formed. Then, a scraper is used to fill the groove area of ​​the screen printing template 200 with the mixed slurry.

[0052] In step 302, since the catalytically active factors 104 are relatively small, if the catalytically active factors 104 are directly printed on the substrate 100 using the screen printing template 200, it is difficult to uniformly print the catalytically active factors 104 in the printing area. By mixing the catalytically active factors 104 with the polymer slurry to form a mixed slurry, and then printing the mixed slurry in the printing area, the catalytically active factors 104 can be uniformly printed in the printing area, thereby improving the uniformity of the metal layer 105 deposited in step 304.

[0053] In some embodiments, the polymer slurry has the property of being easily vaporized and volatilized after being irradiated by a laser of a specific wavelength, and / or the polymer slurry is a water-soluble material and can be washed away during a water washing process.

[0054] In some embodiments, the polymer slurry includes acrylonitrile-butadiene-styrene copolymer, and / or the catalytically active factor 104 includes copper hydroxyphosphate. Copper hydroxyphosphate can be used to catalyze copper deposition. Copper hydroxyphosphate is a non-precious metal catalyst and has a lower cost than traditional precious metal catalysts (such as target catalysts).

[0055] In some embodiments, the groove width of the screen printing template 200 ranges from 10 microns to 30 microns. By using a screen printing template 200 with a narrower groove width, the catalytically active factors 104 can be adhered to the substrate 100 at a closer distance. This allows for the subsequent preparation of extremely fine grid lines based on the closely spaced catalytically active factors 104, thereby improving the photovoltaic conversion efficiency of the resulting photovoltaic cell. Preferably, the groove width of the screen printing template 200 ranges from 10 microns to 20 microns.

[0056] Step 303: irradiating the printed layer with laser light to volatilize the polymer slurry in the printed area and activate the catalytic active factors, thereby obtaining a substrate having the activated catalytic active factors.

[0057] The laser irradiation direction can be as follows: Figure 4Specifically, the laser spot size can be the same as the groove width of the screen printing template 200, or the laser spot size can be slightly larger than the groove width of the screen printing template 200, so as to ensure that all printing areas can be irradiated by the laser. Due to the shielding of the screen printing template 200, it can be ensured that the laser will not irradiate the hollow area covered by the screen printing template 200, thereby causing damage. Figure 5 As shown, after the printing layer 103 is irradiated with laser light, the polymer paste will volatilize, and the catalytic active factors 104 will be activated and can adhere to the substrate 100. After the printing layer 103 is irradiated with laser light, the screen printing template 200 is removed.

[0058] In some embodiments, after the mixed slurry is irradiated with laser light, the residual polymer slurry can be removed to retain the activated catalytic active factors 104 .

[0059] Specifically, the polymer slurry in the printed area partially evaporates, while some residual polymer slurry remains attached to the printed area, so the residual polymer slurry needs to be removed. For example, the polymer slurry can be removed by water washing. Specifically, the substrate 100 with the activated catalytically active factors 104 can be placed in a water washing tank. The gas bubbling in the water washing tank drives the flow of the cleaning liquid, thereby efficiently removing the residual polymer slurry. The activated catalytically active factors 104 can firmly adhere to the surface of the substrate 100 and thus cannot be washed away by water.

[0060] In some embodiments, if gate lines are prepared on both sides of the substrate 100, the activated catalytic activity factors 104 can be prepared on the first side of the substrate 100 based on steps 302 and 303, and then the activated catalytic activity factors 104 can be prepared on the second side of the substrate 100 based on steps 302 and 303, and finally the gate lines can be prepared on both sides of the substrate 100 based on steps 304 and 305. The process of preparing the activated catalytic activity factors 104 on the first side of the substrate 100 can be as follows: Figures 3 to 5 As shown, the process of preparing the activated catalytic active factors 104 on the second side of the substrate 100 can be as follows Figures 6 to 8 As shown, the process of preparing gate lines on both sides of the substrate 100 can be as follows Figures 9 to 11 shown.

[0061] Step 304: Immerse the substrate with the activated catalytic active factors in a chemical plating agent to deposit a metal layer on the printed layer and the side of the substrate.

[0062] Among them, the thickness of the metal layer 105 located in the printing area is greater than the thickness of the metal layer 105 located in the hollow area, and the thickness of the metal layer 105 located in the printing area is greater than the thickness of the metal layer 105 located on the side of the substrate 100. Exemplarily, the thickness of the metal layer 105 located in the printing area can be 20 to 50 times the thickness of the metal layer 105 located in the hollow area.

[0063] In step 304 , a metal layer is prepared by chemical plating reagent. Compared with the preparation of a seed layer by PVD equipment in the electroplating copper process, no PVD equipment is required, thereby reducing the cost of preparing the battery cell.

[0064] In some embodiments, as Figure 9 As shown, the metal layer 105 includes a copper layer 1051. Copper has good conductivity and is relatively low in cost, so the cost of preparing copper grid lines is lower than preparing grid lines using low-temperature silver paste. The substrate 100 with the activated catalytically active factors 104 is immersed in an electroless copper plating reagent to deposit the copper layer 1051 on the printed layer 103 and the sides of the substrate 100.

[0065] In other embodiments, Figure 10 As shown, the metal layer 105 includes a copper layer 1051 and a tin layer 1052 , wherein when depositing the metal layer 105 on the side of the printed layer 103 and the substrate 100 , the copper layer 1051 can be first deposited on the side of the printed layer 103 and the substrate 100 , and then the tin layer 1052 can be deposited on the copper layer 1051 .

[0066] Specifically, the chemical plating reagent includes an electroless copper plating reagent and an electroless tin plating reagent. The substrate 100 having the activated catalytically active factors 104 can first be immersed in the electroless copper plating reagent to deposit a copper layer 1051 on the printed layer 103 and the sides of the substrate 100. The substrate 100 having the copper layer 1051 can then be immersed in an electroless tin plating reagent to deposit a tin layer 1052 on the copper layer 1051. In practical applications, the thickness of the copper layer 1051 and the tin layer 1052 can be controlled by controlling the time that the substrate 100 having the activated catalytically active factors 104 is in the electroless copper plating reagent and the electroless tin plating reagent, respectively. The tin layer 1052 can effectively isolate oxygen, thereby preventing oxidation of the copper layer 1051.

[0067] Step 305: Etch the metal layer located in the printed layer and the metal layer located on the side of the substrate by equal amounts to remove the metal layer located in the hollow area and the metal layer located on the side of the substrate, so that the metal layer in the printed area forms a grid line, thereby obtaining a substrate with a grid line.

[0068] Among them, the substrate with the gate line is exemplified as follows Figure 11Specifically, because the thickness of the metal layer 105 in the printed area is greater than the thickness of the metal layer 105 in the hollow area, and the thickness of the metal layer 105 in the printed area is greater than the thickness of the metal layer 105 on the side of the substrate 100, when the metal layer 105 in the printed area, the metal layer 105 in the hollow area, and the metal layer 105 on the side of the substrate 100 are etched equally, the metal layer 105 in the hollow area and the metal layer 105 on the side of the substrate 100 can be completely removed, while the metal layer 105 in the printed area is partially retained, so that the metal layer 105 in the printed area forms a gate line.

[0069] In some embodiments, when the metal layer 105 located in the printed layer 103 and the metal layer 105 located on the side of the substrate 100 are etched equally, the metal layer 105 located in the printed layer 103 and the metal layer 105 located on the side of the substrate 100 can be etched equally using an acidic reagent to remove the metal layer 105 located in the hollow area and the metal layer 105 located on the side of the substrate 100.

[0070] In some embodiments, after etching the metal layer 105 located on the printed layer 103 and the metal layer 105 located on the side of the substrate 100 by equal amounts, the substrate 100 with the gate lines may be placed in a water washing tank for cleaning and drying.

[0071] In the above embodiment, firstly, since there is no need to use electroplating equipment to electroplate the grid lines, the preparation cost of the cell is reduced. Secondly, the hollow area can be shielded by using the screen printing template 200. When the printed layer 103 is irradiated with a laser, there is no need to use high-precision expensive photolithography equipment. Low-precision laser equipment can be used, which reduces the preparation cost of the cell. In addition, since the mixed slurry does not need to be cured, a polymer slurry with a lower viscosity can be used, and then a screen printing template 200 with an extremely narrow line width can be used to make the catalytic active factors 104 adhere to the substrate 100 with a smaller spacing, so that in the subsequent steps, extremely fine grid lines can be prepared based on the catalytic active factors 104 with a smaller spacing, thereby improving the photovoltaic conversion efficiency of the cell.

[0072] Figure 12 FIG. 1 is a flow chart of a method for preparing an electrode of a silicon heterojunction battery provided by another exemplary embodiment of the present application. Figures 2 to 12 As shown, the method for preparing an electrode of a silicon heterojunction cell includes the following steps 401 to 411. For ease of description, the transparent conductive layer, the protective layer 102 and the printed layer 103 on both sides of the substrate are respectively distinguished as the first and the second.

[0073] Step 401: Provide a substrate.

[0074] The substrate 100 includes a silicon wafer 101, a first transparent conductive layer, a second transparent conductive layer, a first protective layer, and a second protective layer. The silicon wafer 101 has a first side and a second side relative to each other. The first transparent conductive layer and the first protective layer are located on the first side of the silicon wafer 101, and the second transparent conductive layer and the second protective layer are located on the second side of the silicon wafer 101.

[0075] Step 402: Print a mixed slurry of catalytic active factors and polymer slurry on a first side of the substrate using a screen printing template to form a first printed layer, wherein the first printed layer has a printed area and a hollow area.

[0076] Step 403: irradiating the first printed layer with a laser to volatilize the polymer slurry in the printed area of ​​the first printed layer and activate the catalytic active factors, thereby obtaining a substrate having the activated catalytic active factors on the first side.

[0077] Step 404: Remove the remaining polymer slurry by water washing to retain the activated catalytic active factors.

[0078] Specifically, the polymer slurry in the printed area of ​​the first printed layer partially volatilizes, while some residual polymer slurry remains attached to the printed area of ​​the first printed layer, which can be removed in step 404. The activated catalytically active factors 104 can firmly adhere to the surface of the substrate 100 and thus cannot be washed away by water.

[0079] Step 405 : Printing a mixed slurry of the catalytic active factor and the polymer slurry on the second side of the substrate using a screen printing template to form a second printed layer, wherein the second printed layer has a printed area and a hollow area.

[0080] Step 406 : irradiating the second printed layer with a laser to volatilize the polymer paste in the printed area of ​​the second printed layer and activate the catalytic active factors, thereby obtaining a substrate having activated catalytic active factors on both sides.

[0081] Step 407: Remove the remaining polymer slurry by water washing to retain the activated catalytic active factors.

[0082] Specifically, the polymer slurry in the printed area of ​​the second printed layer partially volatilizes, while some residual polymer slurry remains attached to the printed area of ​​the second printed layer. The residual polymer slurry can be removed in step 407. The activated catalytically active factors 104 can firmly adhere to the surface of the substrate 100 and thus cannot be washed away by water.

[0083] Step 408 : Immerse the substrate with activated catalytic active factors on both sides in a chemical copper plating reagent to deposit copper layers on the first printed layer, the second printed layer, and the sides of the substrate, respectively.

[0084] Step 409 : Immerse the substrate having the copper layer in a chemical tin plating reagent to deposit a tin layer on the copper layer.

[0085] Step 410: Etch the copper layer and tin layer located on the first printed layer, the second printed layer and the side of the substrate respectively by equal amounts using an acidic reagent to remove the copper layer and tin layer located in the hollow area of ​​the first printed layer, the copper layer and tin layer located in the hollow area of ​​the second printed layer and the copper layer and tin layer located on the side of the substrate, so that the copper layer and tin layer located in the printing area of ​​the first printed layer and the copper layer and tin layer located in the printing area of ​​the second printed layer form grid lines, thereby obtaining a substrate with grid lines.

[0086] Step 411: Clean the substrate with the gate lines by water washing.

[0087] Exemplary devices

[0088] Combined with the above Figures 1 to 12 , describes the method embodiment of the present application in detail, and the following is combined with Figure 13 , the device embodiment of the present application is described in detail. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment, so for parts not described in detail, reference can be made to the previous method embodiment.

[0089] Figure 13 FIG. 1 is a schematic diagram of the structure of an electrode preparation device for a silicon heterojunction battery provided by an exemplary embodiment of the present application. Figure 13 As shown, the electrode preparation device 500 for a silicon heterojunction battery provided in an embodiment of the present application includes: a preparation device 501 for preparing a protective layer on a pre-provided substrate to obtain a substrate, wherein the substrate has a silicon wafer and a transparent conductive layer; a printing device 502 for printing a mixed slurry of a catalytically active factor and a polymer slurry on the substrate using a screen printing template to form a printed layer, wherein the printed layer has a printed area and a hollow area; a laser device 503 for irradiating the printed layer with a laser to volatilize the polymer slurry in the printed area and activate the catalytically active factor to obtain a substrate having the activated catalytically active factor A deposition device 504 is used to immerse the substrate having the activated catalytic activity factor in a chemical plating reagent to deposit a metal layer on the printing layer and the side of the substrate, wherein the thickness of the metal layer located in the printing area is greater than the thickness of the metal layer located in the hollow area, and the thickness of the metal layer located in the printing area is greater than the thickness of the metal layer located on the side of the substrate; a removal device 505 is used to etch the metal layer located in the printing layer and the metal layer located on the side of the substrate in equal amounts to remove the metal layer located in the hollow area and the metal layer located on the side of the substrate, so that the metal layer in the printing area forms a grid line, thereby obtaining a substrate with a grid line.

[0090] Illustratively, the preparation device 501 includes a physical vapor deposition device, the printing device 502 includes a screen printer, the laser device 503 includes a laser, the deposition device 504 includes a chemical copper plating machine and a chemical tin plating machine, and the removal device 505 includes a wet etching machine.

[0091] In some embodiments, the protective layer includes an indium antimony oxide layer, and the preparation device 501 is further used to deposit the indium antimony oxide layer on the transparent conductive layer by physical vapor deposition.

[0092] In some embodiments, after the mixed slurry is irradiated with laser light, the laser device 503 is further used to remove residual polymer slurry and retain the activated catalytic active factors.

[0093] In some embodiments, the metal layer includes a copper layer and a tin layer, wherein the deposition device 504 is further configured to: deposit a copper layer on the sides of the printed layer and the substrate; and deposit a tin layer on the copper layer.

[0094] In some embodiments, the removal device 505 is further used to: etch the metal layer located on the printed layer and the metal layer located on the side of the substrate equally using an acidic reagent to remove the metal layer located in the hollow area and the metal layer located on the side of the substrate.

[0095] In some embodiments, the silicon wafer has a first side and a second side opposite to each other; wherein the substrate has two transparent conductive layers, wherein the first transparent conductive layer is located on the first side of the silicon wafer, and the second transparent conductive layer is located on the second side of the silicon wafer.

[0096] In some embodiments, the polymer slurry includes acrylonitrile-butadiene-styrene copolymer, and / or the catalytic active factor includes copper hydroxyphosphate.

[0097] In some embodiments, the groove width of the screen printing template ranges from 10 microns to 30 microns.

[0098] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details disclosed above are merely illustrative and facilitating understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0099] The block diagrams of the devices, devices, equipment, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "include," "comprise," "have," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0100] It should also be noted that in the apparatus, device, and method of the present application, each component or each step can be decomposed and / or recombined, and such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0101] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0102] The above description has been provided for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A method for preparing an electrode for a silicon heterojunction battery, characterized in that: include: Providing a substrate, wherein the substrate comprises a silicon wafer; Printing a mixed slurry of catalytic active factors and polymer slurry on the substrate using a screen printing template to form a printing layer, wherein the printing layer has a printing area and a hollow area; irradiating the printed layer with a laser to volatilize the polymer slurry in the printed area and activate the catalytic active factors, thereby obtaining a substrate having the activated catalytic active factors; Immersing the substrate with the activated catalytically active factors in a chemical plating agent to deposit a metal layer on the printed layer and the side of the substrate, wherein the thickness of the metal layer in the printed area is greater than the thickness of the metal layer in the hollow area, and the thickness of the metal layer in the printed area is greater than the thickness of the metal layer on the side of the substrate; The metal layer located at the printing layer and the metal layer located at the side of the substrate are etched equally to remove the metal layer located at the hollow area and the metal layer located at the side of the substrate, so that the metal layer in the printing area forms a grid line, thereby obtaining the substrate with the grid line.

2. The method for preparing an electrode for a silicon heterojunction battery according to claim 1, wherein: The substrate further comprises a transparent conductive layer and a protective layer. The substrate is provided, comprising: Providing a substrate, wherein the substrate has the silicon wafer and the transparent conductive layer; The protective layer is prepared on the transparent conductive layer.

3. The method for preparing an electrode for a silicon heterojunction battery according to claim 2, wherein: The protective layer includes an indium antimony oxide layer; Wherein, the step of preparing the protective layer on the transparent conductive layer comprises: The indium antimony oxide layer is deposited on the transparent conductive layer by physical vapor deposition.

4. The method for preparing an electrode for a silicon heterojunction battery according to claim 1 or 2, wherein: After obtaining the substrate having the activated catalytically active factors, the method further comprises: The residual polymer slurry is removed, and the activated catalytic active factors are retained.

5. The method for preparing an electrode for a silicon heterojunction battery according to claim 1 or 2, wherein: The metal layer includes a copper layer and a tin layer; Wherein, depositing a metal layer on the sides of the printed layer and the substrate includes: depositing the copper layer on the sides of the printed layer and the substrate; The tin layer is deposited on the copper layer.

6. The method for preparing an electrode for a silicon heterojunction battery according to claim 1 or 2, wherein: The step of equally etching the metal layer located on the printed layer and the metal layer located on the side of the substrate comprises: The metal layer located on the printed layer and the metal layer located on the side of the substrate are etched equally by an acidic reagent to remove the metal layer located in the hollow area and the metal layer located on the side of the substrate.

7. The method for preparing an electrode for a silicon heterojunction battery according to claim 1 or 2, wherein: The silicon wafer has a first side and a second side that are opposite; The substrate has two transparent conductive layers, the first transparent conductive layer is located on the first side of the silicon wafer, and the second transparent conductive layer is located on the second side of the silicon wafer.

8. The method for preparing an electrode for a silicon heterojunction battery according to claim 1 or 2, wherein: The polymer slurry includes acrylonitrile-butadiene-styrene copolymer, and / or the catalytic active factor includes copper hydroxyphosphate.

9. The method for preparing an electrode for a silicon heterojunction battery according to claim 1 or 2, wherein: The groove width of the screen printing template ranges from 10 microns to 30 microns.

10. An electrode preparation device for a silicon heterojunction battery, characterized in that: include: A preparation device for preparing a protective layer on a pre-provided substrate to obtain a base plate, wherein the substrate comprises a silicon wafer and a transparent conductive layer; a printing device for printing a mixed slurry of catalytic active factors and polymer slurry on the substrate using a screen printing template to form a printed layer, wherein the printed layer has a printed area and a hollow area; a laser device for irradiating the printed layer with a laser to volatilize the polymer slurry in the printed area and activate the catalytic active factors to obtain a substrate having the activated catalytic active factors; a deposition device, configured to immerse the substrate having the activated catalytically active factors in a chemical plating reagent to deposit a metal layer on the printed layer and the side of the substrate, wherein the thickness of the metal layer in the printed area is greater than the thickness of the metal layer in the hollow area, and the thickness of the metal layer in the printed area is greater than the thickness of the metal layer on the side of the substrate; A removal device is used to etch the metal layer located at the printing layer and the metal layer located at the side of the substrate equally to remove the metal layer located at the hollow area and the metal layer located at the side of the substrate, so that the metal layer in the printing area forms a grid line, thereby obtaining the substrate with the grid line.

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