Method for manufacturing a solar cell and solar cell

Abstract

The present invention provides a method for manufacturing a solar cell and a solar cell, comprising: providing a substrate, and sequentially performing texturing treatment, diffusion treatment, etching treatment, and front and back film layer deposition on the substrate to obtain a solar cell to be printed, the solar cell to be printed including two opposite surfaces; printing a paste on at least one surface of the solar cell to be printed to obtain a solar cell to be sintered, the solar cell to be sintered including a plurality of initially formed grid lines arranged at intervals; performing multiple sintering treatments on each of the initially formed grid lines to form grid lines, wherein each sintering treatment forms a sintering region, and the orthographic projection of the plurality of sintering regions on the solar cell to be sintered at least covers the orthographic projection of the initially formed grid lines on the solar cell to be sintered, and the overlapping area of two adjacent sintering regions is greater than 0 and less than 8.4 mm<supgt;2< / supgt;. This method solves the technical problem of unsatisfactory sintering effect of solar cells in the prior art.

Description

Technical Field

[0001] This application relates to the field of solar cells, and more particularly, to a method for manufacturing a solar cell and a solar cell. Background Art

[0002] During the preparation process of the gate of a solar cell, laser sintering treatment is used. In this process, incomplete action or over-sintering problems are likely to occur, resulting in an unsatisfactory sintering effect and affecting the efficiency of the solar cell.

[0003] Therefore, there is an urgent need for a method for manufacturing a solar cell that can solve the problem of unsatisfactory sintering effect of the solar cell. Summary of the Invention

[0004] The main object of the present invention is to provide a method for manufacturing a solar cell and a solar cell to solve the problem of unsatisfactory sintering effect of the solar cell in the prior art.

[0005] To achieve the above object, according to one aspect of the present invention, a method for manufacturing a solar cell is provided, including: providing a substrate, and sequentially performing texturing treatment, diffusion treatment, etching treatment, and front and back film layer deposition on the substrate to obtain a solar cell to be printed, the solar cell to be printed including two opposite surfaces; printing a paste on at least one of the surfaces of the solar cell to be printed to obtain a solar cell to be sintered, the solar cell to be sintered including a plurality of initially formed grid lines arranged at intervals; performing multiple sintering treatments on each of the initially formed grid lines to form grid lines, wherein each sintering treatment forms a sintering area, and the orthographic projection of the plurality of sintering areas on the solar cell to be sintered at least covers the orthographic projection of the initially formed grid lines on the solar cell to be sintered, and the overlapping area of two adjacent sintering areas is greater than 0 and less than 8.4 mm 2 。

[0006] Further, in the first direction, the minimum distance between the edge of the sintering area and the edge of the initially formed grid line ranges from 0 to 400 μm, wherein the first direction is the direction in which the plurality of initially formed grid lines are arranged.

[0007] Further, in the same grid line, there is a gap between the centers of two adjacent sintering areas, and the gap is greater than 0 and less than 0.5 mm.

[0008] Further, the minimum distance between the center point of any one of the sintering areas and the geometric center of the initially formed grid line ranges from 0 to 0.25 mm.

[0009] Further, the moving direction of each sintering treatment is the same as the extending direction of the grid line.

[0010] Further, the initial positions of each of the sintering treatments are located at the same end of the initial grid lines.

[0011] Further, in the first direction, the maximum width range of the sintering region is 80 - 120 μm, where the first direction is the direction in which a plurality of the initial grid lines are arranged.

[0012] Further, each of the sintering treatments respectively includes: moving a laser to irradiate the initial grid lines, and applying a reverse bias voltage to the initial grid lines, where the wavelength range of the laser is 1000 nm - 1064 nm, and the range of the reverse bias voltage is -30 V to -5 V.

[0013] Further, one sintering region includes a plurality of sub - regions arranged along the second direction, and the center points of each of the sub - regions are located on the same straight line, where the second direction is the extending direction of the initial grid lines.

[0014] In order to achieve the above object, according to one aspect of the present invention, a solar cell is provided, and the solar cell is obtained by processing using any one of the above - mentioned methods.

[0015] Applying the technical solution of the present invention, first, a substrate is provided, and the substrate is successively subjected to texturing treatment, diffusion treatment, etching treatment, and front - and back - side film deposition to obtain a solar cell to be printed. The solar cell to be printed includes two opposite surfaces; then, a paste is printed on at least one surface of the solar cell to be printed to obtain a solar cell to be sintered. The solar cell to be sintered includes a plurality of initial grid lines arranged at intervals; finally, each of the initial grid lines is respectively subjected to multiple sintering treatments to form grid lines. Among them, each sintering treatment forms a sintering region, and the orthographic projection of a plurality of sintering regions on the solar cell to be sintered at least covers the orthographic projection of the initial grid lines on the solar cell to be sintered, and the overlapping area of two adjacent sintering regions is greater than 0 and less than 8.4 mm 2 . In this solution, after the texturing, diffusion, etching, front - and back - side film deposition, and paste printing of the solar cell are completed to obtain the solar cell to be sintered, through multiple sintering treatments of the initial grid lines, the next sintering treatment can re - sinter and compensate for the incomplete sintering phenomenon generated by the previous sintering treatment, thereby solving the problem of under - sintering in the single - sintering process; in addition, since the plurality of sintering regions obtained by multiple sintering treatments can cover the initial grid lines, and the overlapping area of two adjacent sintering regions is greater than 0 and less than 8.4 mm 2 , on the basis of avoiding the problem of under - sintering, the problem of over - sintering can be further prevented, the sintering effect of the solar cell can be improved, and the technical problem that the sintering effect of the solar cell in the prior art is not ideal is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings forming a part of this invention are used to provide a further understanding of the invention. The schematic embodiments and descriptions thereof of the invention are used to explain the invention and do not unduly limit the invention. In the drawings:

[0017] Figure 1 A schematic flow chart of a method for manufacturing a solar cell provided according to an embodiment of the present application is shown;

[0018] Figure 2 A schematic structural diagram of a solar cell to be printed provided according to an embodiment of the present application is shown;

[0019] Figure 3 Is shown in Figure 2 Based on this, a schematic structural diagram of a solar cell to be sintered obtained by printing a paste is shown;

[0020] Figure 4 Is shown in Figure 3 Based on this, a schematic structural diagram of a solar cell obtained by performing multiple sintering processes is shown;

[0021] Figure 5 A schematic structural diagram of a top view of a solar cell according to an embodiment of the present application is shown.

[0022] Among them, the above-mentioned drawings include the following reference numerals:

[0023] 100, the first passivation layer; 101, the doped conductive layer; 102, the tunneling dielectric layer; 103, the substrate; 104, the doped layer; 105, the second passivation layer; 106, the initial grid line; 107, the gate; 108, the sintering area; H1, the predetermined distance. Detailed implementation manners

[0024] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0025] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present invention are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so as to implement the embodiments of the present invention described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0027] As introduced in the background art, the sintering effect of solar cells in the prior art is not ideal. To solve the above technical problems, the present application proposes a method for manufacturing a solar cell and a solar cell.

[0028] Figure 1 It is a schematic flow chart of a method for manufacturing a solar cell according to an embodiment of the present application. As Figure 1 shown, it includes:

[0029] Step S201: Provide a substrate, and sequentially perform texturing treatment, diffusion treatment, etching treatment, and front and back film layer deposition on the above substrate to obtain a solar cell to be printed. The above solar cell to be printed includes two opposite surfaces;

[0030] During the manufacturing process of the solar cell, the texturing treatment can remove the mechanical damage layer on the substrate surface, increase the surface area, reduce the reflectivity, and remove impurities. The textured structure formed after the texturing treatment can be a pyramid structure or an irregular concavo-convex structure. The diffusion treatment can further form a PN junction on the substrate. For an N-type silicon substrate, during the diffusion process, a layer of phosphosilicate glass is formed on the substrate surface. It should be noted that this film layer will be removed in the subsequent etching process. The etching treatment is used to remove the edge conductive layer and phosphosilicate glass formed during the diffusion process to prevent the PN junction from short-circuiting. The front and back film layer deposition treatment is used to deposit a passivation film and an antireflection film on the front and back of the cell, thereby further improving the cell efficiency. For example, the front film layer can use silicon nitride material to reduce reflection and passivate the surface. The back film layer can use materials such as alumina and silicon nitride to passivate and reduce the back surface recombination.

[0031] Figure 2 It is a schematic structural diagram of a solar cell to be printed according to an embodiment of the present application. As Figure 2As shown in the figure, the solar cell to be printed includes, from bottom to top, a first passivation layer 100, a doped conductive layer 101, a tunneling dielectric layer 102, a substrate 103, a doped layer 104, and a second passivation layer 105. Among them, the two opposite surfaces of the solar cell to be printed are respectively the surface of the first passivation layer 100 away from the doped conductive layer 101 and the surface of the second passivation layer 105 away from the doped layer 104. For example, the substrate 103 can be an N-type substrate 103 or a P-type substrate 103. And, in the thickness direction of the solar cell to be printed, both surfaces of the substrate 103 can be used to receive light. Further, a doped layer 104 and a second passivation layer 105 are sequentially provided on one surface of the substrate 103; a tunneling dielectric layer 102, a doped conductive layer 101, and a first passivation layer 100 are sequentially provided on the other surface of the substrate 103. In practical applications, the solar cell to be printed can form at least part of different types of cells such as Tunnel Oxide Passivating Contacts (TOPCon) cells and Back Contact (BC) cells.

[0032] Step S202: Printing a paste on at least one of the surfaces of the solar cell to be printed to obtain a solar cell to be sintered, where the solar cell to be sintered includes a plurality of initial grid lines arranged at intervals;

[0033] The above paste treatment can adopt at least one of screen printing process, gravure printing process, letterpress printing process, flexographic printing process, laser transfer printing process, inkjet printing process, and 3D printing process. The range of the specific area of the above paste can be set according to actual situations, and this application does not make specific restrictions. Figure 3 is a schematic structural diagram of a solar cell to be sintered according to an embodiment of the present application. As Figure 3 shown, a paste is printed on the side of the second passivation layer 105 away from the doped layer 104 to obtain an initial grid line 106. The positional relationship between the remaining first passivation layer 100, doped conductive layer 101, tunneling dielectric layer 102, and substrate 103 is the same as that in Figure 2 and will not be elaborated here.

[0034] Step S203: Performing multiple sintering treatments on each of the above initial grid lines to form grid lines. Among them, each of the above sintering treatments forms a sintering area, and the orthographic projection of the multiple sintering areas on the solar cell to be sintered at least covers the orthographic projection of the initial grid line on the solar cell to be sintered, and the overlapping area of two adjacent sintering areas is greater than 0 and less than 8.4 mm 2 .

[0035] The above-mentioned sintering treatment refers to that through heat treatment, at least part of the paste penetrates the corresponding part of the film layer structure on the substrate to form grid lines. In practical applications, the above-mentioned sintering treatment can achieve local heating and rapid cooling by precisely controlling the energy and irradiation time of the laser, reduce the heat-affected area, and improve the sintering quality and battery performance at the same time. The above-mentioned laser can be a line laser emitted by a laser. During the continuous movement of the laser, the irradiation area formed by the linear light beam is the above-mentioned sintering area. During the process of the laser emitting laser, the emitter can emit continuously or at intervals.

[0036] Figure 4 is a schematic structural diagram of a solar cell according to an embodiment of the present application. As Figure 4 shown, the initial grid lines are sintered. In the thickness direction of the substrate, part of the paste burns through the above-mentioned second passivation layer 105 to form the above-mentioned grid electrode 107. One end of the above-mentioned grid electrode 107 is in contact with the doping layer 104 to form an ohmic contact, forming a tiny alloy junction, thereby reducing the contact resistance and being beneficial to improving the electron transfer efficiency. The positional relationship of the remaining above-mentioned first passivation layer 100, doped conductive layer 101, tunneling dielectric layer 102, and substrate 103 is the same as that in Figure 2 , which will not be elaborated here. It should be noted that the moving directions of the above-mentioned multiple sintering treatments ( Figure 5 the direction indicated by the arrow in) can be the same or opposite. The shape of the above-mentioned sintering area includes but is not limited to shapes such as rectangles, circles, or ellipses. Moreover, multiple sintering areas cover the above-mentioned initial grid lines, and a good sintering effect can be achieved.

[0037] In the above-mentioned embodiment, a method for manufacturing a solar cell is provided. First, a substrate is provided, and the substrate is sequentially subjected to texturing treatment, diffusion treatment, etching treatment, and front and back surface film layer deposition to obtain a solar cell to be printed. The solar cell to be printed includes two opposite surfaces; then, a paste is printed on at least one surface of the solar cell to be printed to obtain a solar cell to be sintered. The solar cell to be sintered includes a plurality of initial grid lines arranged at intervals; finally, each initial grid line is subjected to multiple sintering treatments to form grid lines. Among them, each sintering treatment forms a sintering area, and the orthographic projection of multiple sintering areas on the solar cell to be sintered at least covers the orthographic projection of the initial grid lines on the solar cell to be sintered, and the overlapping area of two adjacent sintering areas is greater than 0 and less than 8.4 mm 2。In this solution, after the texturing, diffusion, etching, deposition of front and back film layers, and printing of paste of the solar cell are completed to obtain the solar cell to be sintered, the initial grid lines are sintered multiple times. In this way, the next sintering process can re-sinter the incomplete sintering phenomenon generated by the previous sintering process to make up for it, thereby solving the problem of underfiring in the single sintering process. In addition, since the multiple sintering areas obtained by the multiple sintering processes can cover the initial grid lines, and the overlapping area of two adjacent sintering areas is greater than 0 and less than 8.4 mm 2 , on the basis of avoiding the problem of underfiring, the problem of overfiring can be further prevented, the sintering effect of the solar cell can be improved, and the technical problem of the unsatisfactory sintering effect of the solar cell in the prior art is solved.

[0038] In the first direction, the range of the minimum distance between the edge of the sintering area and the edge of the initial grid line is 0 - 400 μm, where the first direction is the direction in which the multiple initial grid lines are arranged. The setting of the minimum distance between the edge of the sintering area and the edge of the initial grid line can further prevent the light spot in the sintering process from completely covering the grid line, further avoid the over-sintering phenomenon caused by local overheating, and can precisely control the sintering area, avoid unnecessary energy waste, further improve the sintering efficiency and reduce the cost.

[0039] As Figure 5 shown, the minimum distance between the edge of the sintering area 108 and the edge of the initial grid line 106 is a predetermined distance H1, and the predetermined distance H1 can be any value within the above range. For example, the minimum distance between the edge of the sintering area 108 and the edge of the initial grid line 106 can be 100 μm, 200 μm, 300 μm, and 400 μm.

[0040] In the same grid line, there is a gap between the center points of two adjacent sintering areas, and the gap is greater than 0 and less than 0.5 mm. The above design can ensure an appropriate separation between the central parts of the sintering areas, further avoid the excessive fusion of the sintering areas, and thus further improve the sintering effect.

[0041] In this embodiment, the gap between the center points of two adjacent sintering areas in the same grid line can be any value, such as 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm.

[0042] The range of the minimum distance between the center point of any sintering area and the geometric center of the initial grid line is 0 - 0.25 mm. The above setting can further precisely control the distance between the center point of the sintering area and the geometric center of the initial grid line, further ensure the uniform distribution of the sintering areas, and further improve the photoelectric conversion efficiency of the solar cell.

[0043] In practical applications, among multiple sintering regions formed on the same grid line, the minimum distance between the center point of each sintering region and the geometric center of the initial grid line can be the same or different. Those skilled in the art can set the same or different minimum distances according to the actual situation. The minimum distance between the center point of any one of the above-mentioned sintering regions and the geometric center of the above-mentioned initial grid line can be any value within the above range. For example: 0.1 mm, 0.15 mm, 0.2 mm, and 0.25 mm.

[0044] The moving direction of each of the above-mentioned sintering processes is the same as the extending direction of the grid line. Since the laser is emitted by a laser device, the moving direction of the above-mentioned sintering process can be regarded as the moving direction of the laser device, and the moving direction of the above-mentioned laser device is the same as the extending direction of the grid line. Compared with the way that the moving direction of the laser device intersects with the extending direction of the grid line, a larger area on the grid line can be sintered, thereby further improving the efficiency of the sintering process.

[0045] In practical applications, the moving directions of each of the above-mentioned sintering processes can be the same. That is to say, the moving direction of each sintering process is to move from the first end of the grid line along the extending direction to the second end of the grid line. The moving directions of each of the above-mentioned sintering processes can be opposite. That is to say, the moving direction of the previous sintering process is to move from the first end of the grid line along the extending direction to the second end of the grid line, and the moving direction of the next sintering process is to move from the second end of the grid line along the extending direction to the first end of the grid line. The second processing method can save the time for the laser device to move from the second end of the grid line along the extending direction to the first end of the grid line in the next sintering process, and can further improve the efficiency of the sintering process.

[0046] In some embodiments, the initial positions of each of the above-mentioned sintering processes are located at the same end of the above-mentioned initial grid line. During the laser processing, as time increases, due to the influence of thermal effects, changes in the surface conversion of materials, and changes in processing accuracy and efficiency, the sintering effect will change significantly with the increase of time. Initially, it can usually improve the surface state of the material and processing accuracy. However, as time prolongs, heat accumulation and energy overload may lead to a decrease in the surface quality of the material, deterioration of the microstructure, and a reduction in processing efficiency. Therefore, the same initial positions of each of the above-mentioned sintering processes can ensure that the sintering effects of each sintering process are as similar as possible, ensure the uniformity of the sintering process for each sintering region, and further improve the sintering effect.

[0047] In some other embodiments, in the first direction, the maximum width of the above-mentioned sintering region ranges from 80 to 120 μm, where the first direction is the direction in which a plurality of the above-mentioned initial grid lines are arranged. The setting of the maximum width of the sintering region can significantly reduce the heat affected zone, minimize the thermal deformation and residual stress during the sintering process, further avoid material damage caused by overheating, and at the same time can further improve the sintering accuracy during the sintering process. In addition, the size setting of the sintering region can further precisely control the width, height and depth of the melt track, thereby further achieving higher geometric accuracy.

[0048] In practical applications, the maximum width of the above-mentioned sintering region can be any value within the above range. For example, the maximum width of the above-mentioned sintering region can be 80 μm, 90 μm, 100 μm, 110 μm and 120 μm.

[0049] In some specific applications, each of the above-mentioned sintering processes includes: using a laser to move and irradiate the above-mentioned initial grid lines, and applying a reverse bias voltage to the above-mentioned initial grid lines, where the wavelength range of the laser is 1000 nm to 1064 nm, and the range of the reverse bias voltage is -30 V to -5 V. Using the above laser wavelength can not only ensure the absorption efficiency of the initial grid lines, further improve the sintering effect, but also ensure the sintering depth, further achieving high-precision sintering. Using the above reverse bias voltage can not only further reduce the recombination probability of carriers, but also further reduce the risk of damaging the solar cell.

[0050] In practical applications, the reverse bias voltage of the above-mentioned laser and the laser wavelength range can be any value within the above range. For example, the wavelength of the above-mentioned laser can be 1000 nm, 1020 nm, 1040 nm and 1064 nm, and the reverse bias voltage can be -30 V, -25 V, -20 V, -15 V, -10 V and -5 V. And the reverse bias voltage of the above-mentioned laser and the laser wavelength range can be flexibly set according to actual usage requirements.

[0051] In yet another embodiment of the present application, one of the above-mentioned sintering regions includes a plurality of sub-regions arranged along the second direction, and the center points of each of the above-mentioned sub-regions are located on the same straight line, where the second direction is the extending direction of the above-mentioned initial grid lines. In the case where the laser emits light beams at intervals, during the continuous movement of the laser, a plurality of spaced sub-regions are formed, and the plurality of sub-regions form the above-mentioned sintering region. That is to say, during the continuous movement of the laser, it moves linearly along the extending direction of the initial grid lines. The above setting can further improve the uniformity of the sintering effect.

[0052] The above technical solution of the present application can be used in all-back-contact cells of the zero busbar technology (0BB) or multi-busbar technology (MBB), all-back-contact cells (IBC, Interdigitated Back Contact), all-back-contact solar cells (ABC, All Back Contact), hybrid passivated back-contact cells (HPBC, Hybrid Passivated Back Contact), passivated emitter and rear cells (PERC, Passivated Emitter and Rear Cell), tunnel oxide passivated contact cells (TOPcon, Tnuuel Oxide Passivatedcontact), TOPcon-IBC cells, crystalline silicon heterojunction solar cells (HJT, Heterojunction with Intrinsic Thin-layer), perovskite tandem cells, flexible cells and other photovoltaic cells.

[0053] An embodiment of the present application further provides a solar cell as described above, which is obtained by the manufacturing method of any one of the above solar cells. As Figure 4 shown, the solar cell includes:

[0054] A substrate 103, the substrate 103 having opposite first and second surfaces;

[0055] The substrate 103 may be an N-type substrate 103 or a P-type substrate 103. And, in the thickness direction of the solar cell to be printed, both the first surface and the second surface of the substrate 103 can be used to receive light.

[0056] A tunneling dielectric layer 102, located on the first surface;

[0057] The tunneling dielectric layer 102 is disposed on the first surface, that is, the back surface of the substrate 103, so that the tunneling dielectric layer 102 chemically passivates the back surface of the substrate 103. Specifically, by saturating the dangling bonds on the back surface of the substrate 103, the density of defect states on the back surface of the substrate 103 is reduced, and the recombination centers on the surface of the substrate 103 are reduced to lower the carrier recombination rate. In some embodiments, the material of the tunneling dielectric layer 102 may include at least one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, and magnesium fluoride.

[0058] A doped conductive layer 101, located on the side of the tunneling dielectric layer 102 away from the substrate 103;

[0059] The doped conductive layer 101 and the tunneling dielectric layer 102 form a passivated contact structure, which can form a band bending on the backlight side of the substrate 103 to achieve selective carrier transport. The material of the doped conductive layer 101 may include at least one of amorphous silicon, polycrystalline silicon, and silicon carbide. The doped conductive layer 101 may be doped with a doping element of the same type as the substrate 103. For example, if the doping type of the substrate 103 is P-type, the doping type in the doped conductive layer 101 may also be P-type; if the doping type of the substrate 103 is N-type, the doping type in the doped conductive layer 101 may also be N-type.

[0060] The first passivation layer 100 is located on the side of the doped conductive layer 101 away from the tunneling dielectric layer 102;

[0061] In practical applications, the PECVD method can be used to form the first passivation layer 100 on the side of the doped conductive layer 101 away from the tunneling dielectric layer 102. The first passivation layer 100 can play a good passivation role on the back of the substrate 103, reduce the density of defect states on the back of the substrate 103, and preferably suppress the carrier recombination on the back of the substrate 103. The material of the first passivation layer 100 may include at least one of silicon oxide, aluminum oxide, silicon nitride, and silicon oxynitride.

[0062] The doped layer 104 is located on the second surface;

[0063] The doping type of the doped layer 104 is opposite to that of the substrate 103, and the doped layer 104 and the substrate 103 form a PN junction. In some embodiments, the material of the doped layer 104 may be the same as that of the substrate 103.

[0064] The second passivation layer 105 is located on the side of the doped layer 104 away from the substrate 103;

[0065] The second passivation layer 105 can achieve a good antireflection effect, reduce the reflection of incident light on the front of the substrate 103, and improve the utilization rate of incident light by the substrate 103. The material of the second passivation layer 105 may include at least one of silicon oxide, aluminum oxide, silicon nitride, and silicon oxynitride.

[0066] The gate 107 is located on the surface of the second passivation layer 105 away from the doped layer 104 and is in contact with the doped layer 104.

[0067] The above gate is obtained by sintering the initial gate line, and in the thickness direction of the substrate, part of the paste burns through the second passivation layer 105.

[0068] The solar cell in the above embodiment is manufactured by the manufacturing method of the above solar cell. In this manufacturing method, first, a substrate is provided, and the substrate is successively subjected to texturing treatment, diffusion treatment, etching treatment, and front and back film layer deposition to obtain a solar cell to be printed. The solar cell to be printed includes two opposite surfaces; then, a paste is printed on at least one surface of the solar cell to be printed to obtain a solar cell to be sintered. The solar cell to be sintered includes a plurality of initially formed grid lines arranged at intervals; finally, each of the initially formed grid lines is subjected to multiple sintering treatments to form grid lines. Among them, each sintering treatment forms a sintering region, and the orthographic projection of the multiple sintering regions on the solar cell to be sintered at least covers the orthographic projection of the initially formed grid lines on the solar cell to be sintered, and the overlapping area of two adjacent sintering regions is greater than 0 and less than 8.4 mm 2 In this solution, after the texturing, diffusion, etching, front and back film layer deposition, and paste printing of the solar cell are completed to obtain the solar cell to be sintered, by performing multiple sintering treatments on the initially formed grid lines, the next sintering treatment can re-sinter and compensate for the incomplete sintering phenomenon generated by the previous sintering treatment, thereby solving the problem of under-sintering that occurs during a single sintering process; in addition, since the multiple sintering regions obtained by the multiple sintering treatments can cover the initially formed grid lines, and the overlapping area of two adjacent sintering regions is greater than 0 and less than 8.4 mm 2 , on the basis of avoiding the problem of under-sintering, the problem of over-sintering can be further prevented, the sintering effect of the solar cell can be improved, and the technical problem of the unsatisfactory sintering effect of the solar cell in the prior art is solved.

[0069] Next, the above solar cell of the present application will be specifically described in combination with specific examples and comparative examples.

[0070] Example

[0071] This example provides a manufacturing method of a solar cell, including:

[0072] Provide a substrate, and successively perform texturing treatment, diffusion treatment, etching treatment, and front and back film layer deposition on the above substrate to obtain a solar cell to be printed. The above solar cell to be printed includes two opposite surfaces;

[0073] Print a paste on at least one of the above surfaces of the above solar cell to be printed to obtain a solar cell to be sintered. The above solar cell to be sintered includes a plurality of initially formed grid lines arranged at intervals;

[0074] Perform multiple sintering processes on each of the above-mentioned initial grid lines to form grid lines. Among them, each of the above-mentioned sintering processes forms a sintering region, and the orthographic projections of multiple above-mentioned sintering regions on the above-mentioned solar cell to be sintered at least cover the orthographic projection of the above-mentioned initial grid line on the above-mentioned solar cell to be sintered, and the overlapping area of two adjacent above-mentioned sintering regions is greater than 0 and less than 8.4 mm 2 。

[0075] Comparative example

[0076] This embodiment provides a method for manufacturing a solar cell, including:

[0077] Provide a substrate, and perform texturing treatment, diffusion treatment, etching treatment, and front and back film layer deposition on the above-mentioned substrate in sequence to obtain a solar cell to be printed. The above-mentioned solar cell to be printed includes two opposite surfaces;

[0078] Print a paste on at least one of the above-mentioned surfaces of the above-mentioned solar cell to be printed to obtain a solar cell to be sintered. The above-mentioned solar cell to be sintered includes a plurality of initial grid lines arranged at intervals;

[0079] Perform a single sintering process on each of the above-mentioned initial grid lines to form grid lines. Among them, the orthographic projection of the sintering region formed by the above-mentioned sintering process on the above-mentioned solar cell to be sintered at least covers the orthographic projection of the above-mentioned initial grid line on the above-mentioned solar cell to be sintered.

[0080] Test the power of the solar cells produced in the above-mentioned embodiment and comparative example using a digital source meter device, and the test results are shown in Table 1.

[0081] Table 1

[0082]

[0083] Before performing the sintering process, both the comparative example and the embodiment perform steps such as texturing treatment, diffusion treatment, etching treatment, front and back film layer deposition, and printing of the paste to obtain a solar cell to be sintered. The difference is that the comparative example only performs a single sintering process, and the formed sintering region completely covers the initial grid line. The embodiment performs multiple sintering processes, and the obtained multiple sintering regions cover the above-mentioned initial grid line, and the overlapping area of two adjacent above-mentioned sintering regions is greater than 0 and less than 8.4 mm 2 。It can be seen from Table 1 that compared with the comparative example, the conversion efficiency of the solar cell in the embodiment is increased by 0.04%, and the fill factor is increased by 0.11%. Thus, it can be seen that the solar cell produced by the method for manufacturing a solar cell provided in the embodiment of the present application has improved sintering effect while the conversion efficiency is also improved.

[0084] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0085] 1. In the method for manufacturing a solar cell of the present application, first, a substrate is provided, and the substrate is successively subjected to texturing treatment, diffusion treatment, etching treatment, and front and back film layer deposition to obtain a solar cell to be printed, and the solar cell to be printed includes two opposite surfaces; then, a paste is printed on at least one surface of the solar cell to be printed to obtain a solar cell to be sintered, and the solar cell to be sintered includes a plurality of initially spaced grid lines; finally, each of the initially spaced grid lines is subjected to multiple sintering treatments to form grid lines, wherein each sintering treatment forms a sintering region, and the orthographic projection of the multiple sintering regions on the solar cell to be sintered at least covers the orthographic projection of the initially spaced grid lines on the solar cell to be sintered, and the overlapping area of two adjacent sintering regions is greater than 0 and less than 8.4 mm 2 . In this solution, after the texturing, diffusion, etching, front and back film layer deposition, and paste printing of the solar cell are completed to obtain the solar cell to be sintered, by performing multiple sintering treatments on the initially spaced grid lines, the next sintering treatment can re-sinter and compensate for the incomplete sintering phenomenon generated by the previous sintering treatment, thereby solving the problem of under-sintering during a single sintering process; in addition, since the multiple sintering regions obtained by the multiple sintering treatments can cover the initially spaced grid lines, and the overlapping area of two adjacent sintering regions is greater than 0 and less than 8.4 mm 2 . On the basis of avoiding the problem of under-sintering, the problem of over-sintering can be further prevented, the sintering effect of the solar cell can be improved, and the technical problem of the unsatisfactory sintering effect of the solar cell in the prior art is solved.

[0086] 2. The solar cell of the present application is manufactured by using the above method for manufacturing a solar cell. In this manufacturing method, first, a substrate is provided, and the substrate is successively subjected to texturing treatment, diffusion treatment, etching treatment, and front and back film layer deposition to obtain a solar cell to be printed, and the solar cell to be printed includes two opposite surfaces; then, a paste is printed on at least one surface of the solar cell to be printed to obtain a solar cell to be sintered, and the solar cell to be sintered includes a plurality of initially spaced grid lines; finally, each of the initially spaced grid lines is subjected to multiple sintering treatments to form grid lines, wherein each sintering treatment forms a sintering region, and the orthographic projection of the multiple sintering regions on the solar cell to be sintered at least covers the orthographic projection of the initially spaced grid lines on the solar cell to be sintered, and the overlapping area of two adjacent sintering regions is greater than 0 and less than 8.4 mm 2。In this solution, after the texturing, diffusion, etching, deposition of front and back film layers, and printing of paste of the solar cell are completed to obtain the solar cell to be sintered, the initial grid lines are sintered multiple times. In this way, the next sintering treatment can re-sinter the incomplete sintering phenomenon generated by the previous sintering treatment to make up for it, thereby solving the problem of underfiring during a single sintering process; in addition, since the multiple sintering regions obtained by the multiple sintering treatments can cover the initial grid lines, and the overlapping area of two adjacent sintering regions is greater than 0 and less than 8.4 mm 2 , on the basis of avoiding the problem of underfiring, the problem of overfiring can be further prevented, the sintering effect of the solar cell can be improved, and the technical problem of the unsatisfactory sintering effect of the solar cell in the prior art is solved.

Claims

1. A method for manufacturing a solar cell, characterized in that: include: Providing a substrate, and sequentially performing a texturing process, a diffusion process, an etching process, and a front and back film deposition process on the substrate to obtain a solar cell to be printed, wherein the solar cell to be printed includes two opposite surfaces; Printing slurry on at least one of the surfaces of the solar cell to be printed to obtain a solar cell to be sintered, wherein the solar cell to be sintered comprises a plurality of initial grid lines arranged at intervals; Each of the initial grid lines is subjected to multiple sintering treatments to form grid lines, wherein each sintering treatment forms a sintering region, and the orthographic projections of the multiple sintering regions on the solar cell to be sintered at least cover the orthographic projections of the initial grid lines on the solar cell to be sintered, and the overlapping area of ​​two adjacent sintering regions is greater than 0 and less than 8.4 mm 2 , In a first direction, a minimum distance between an edge of the sintering region and an edge of the initial gate line ranges from 0 to 400 μm, wherein the first direction is a direction in which a plurality of the initial gate lines are arranged.

2. The method for manufacturing a solar cell according to claim 1, characterized in that: In the same grid line, center points of two adjacent sintering regions have a spacing, and the spacing is greater than 0 and less than 0.5 mm.

3. The method for manufacturing a solar cell according to claim 1, characterized in that: The minimum distance between the center point of any one of the sintering regions and the geometric center of the initial grid line is in the range of 0 to 0.25 mm.

4. The method for manufacturing a solar cell according to claim 1, characterized in that: The moving direction of each sintering process is the same as the extending direction of the gate line.

5. The method for manufacturing a solar cell according to claim 1, characterized in that: The initial positions of the sintering processes are located at the same end of the initial grid lines.

6. The method for manufacturing a solar cell according to claim 1, characterized in that: In a first direction, a maximum width of the sintering region ranges from 80 to 120 μm, wherein the first direction is a direction in which the plurality of initial gate lines are arranged.

7. The method for manufacturing a solar cell according to claim 1, characterized in that: Each of the sintering processes comprises: The initial grid line is irradiated with laser movement, and a reverse bias voltage is applied to the initial grid line, wherein the wavelength range of the laser is 1000nm~1064nm, and the range of the reverse bias voltage is -30V~-5V.

8. The method for manufacturing a solar cell according to claim 1, characterized in that: One of the sintering regions includes a plurality of sub-regions arranged along a second direction, and the center points of the sub-regions are located on the same straight line, wherein the second direction is the extension direction of the initial gate lines.

9. A solar cell, characterized in that: The solar cell is obtained by using the solar cell manufacturing method according to any one of claims 1 to 8.

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