Manufacturing method of solar cell and solar cell

Abstract

The invention provides a solar cell manufacturing method and a solar cell, and the method comprises the steps: providing a substrate, carrying out the texturing, diffusion, etching and front and back film layer deposition of the substrate in sequence, and obtaining a to-be-printed solar cell, the to-be-printed solar cell comprises two opposite surfaces; paste is printed on at least one surface of the solar cell to be printed, a solar cell to be sintered is obtained, and the solar cell to be sintered comprises a plurality of initial grid lines arranged at intervals; the initial grid lines are subjected to multiple times of sintering treatment to form the grid lines, one sintering area is formed in each time of sintering treatment, 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 lines on the solar cell to be sintered, and the overlapping area of every two adjacent sintering areas is larger than 0 and smaller than 8.4 mm < 2 >. The method solves the technical problem that the sintering effect of the solar cell is not ideal in the prior art.

Description

Technical Field

[0001] The present application relates to the field of solar cells, and in particular to a method for manufacturing a solar cell and a solar cell. Background Art

[0002] During the preparation of the grid of the solar cell, laser sintering is used. During this process, incomplete action or over-sintering is prone to occur, resulting in 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 purpose of the present invention is to provide a method for manufacturing a solar cell and a solar cell, so as to solve the problem that the sintering effect of the solar cell in the prior art is not ideal.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a method for manufacturing a solar cell is provided, comprising: providing a substrate, and sequentially performing a texturing treatment, a diffusion treatment, an etching treatment, and a front and back film deposition on the substrate to obtain a solar cell to be printed, wherein the solar cell to be printed includes two opposite surfaces; printing a 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 includes a plurality of initial grid lines arranged at intervals; performing a sintering treatment on each of the initial grid lines for multiple times to form grid lines, wherein each sintering treatment forms a sintering area, and the orthographic projections of the plurality of sintering areas 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 areas is greater than 0 and less than 8.4 mm 2 .

[0006] Further, 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.

[0007] Furthermore, 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.

[0008] Furthermore, 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.

[0009] Furthermore, the moving direction of each of the sintering processes is the same as the extending direction of the gate lines.

[0010] Furthermore, the initial positions of the sintering processes are located at the same end of the initial gate lines.

[0011] Furthermore, 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.

[0012] Furthermore, each of the sintering processes includes: using laser to move and irradiate the initial grid lines, and applying a reverse bias voltage to the initial grid lines, wherein the wavelength range of the laser is 1000nm~1064nm, and the range of the reverse bias voltage is -30V~-5V.

[0013] Furthermore, 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 an extension direction of the initial gate lines.

[0014] In order to achieve the above objective, according to one aspect of the present invention, a solar cell is provided. The solar cell is processed by any one of the above methods.

[0015] According to the technical solution of the present invention, first, a substrate is provided, and the substrate is subjected to a texturing treatment, a diffusion treatment, an etching treatment, and a front and back film deposition in sequence to obtain a solar cell to be printed, wherein the solar cell to be printed includes two opposite surfaces; then, a slurry is printed on at least one surface of the solar cell to be printed to obtain a solar cell to be sintered, wherein the solar cell to be sintered includes a plurality of initial grid lines arranged at intervals; finally, each initial grid line is subjected to a plurality of sintering treatments to form a grid line, wherein each sintering treatment forms a sintering region, and the orthographic projections of the plurality of 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 this scheme, after the solar cell is textured, diffused, etched, deposited on the front and back layers, and printed with slurry, and the solar cell to be sintered is obtained, the initial grid line is sintered multiple times, so that the next sintering process can sinter again to compensate for the incomplete sintering caused by the previous sintering process, thereby solving the problem of under-sintering in one sintering process; in addition, since multiple sintering areas obtained by multiple sintering processes can cover the initial grid line, and the overlapping area of ​​two adjacent sintering areas is greater than 0 and less than 8.4mm 2 On the basis of avoiding the problem of under-burning, the problem of over-burning can be further prevented, the sintering effect of solar cells can be improved, and the technical problem of unsatisfactory sintering effect of solar cells in the prior art is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0017] Figure 1 A schematic diagram of a process of manufacturing a solar cell provided in accordance with an embodiment of the present application is shown;

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

[0019] Figure 3 Shown in Figure 2 Schematic diagram of the structure of a solar cell to be sintered by printing slurry based on the present invention;

[0020] Figure 4 Shown in Figure 3 A schematic diagram of the structure of a solar cell obtained by performing multiple sintering processes on the basis of FIG.

[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] The above drawings include the following reference numerals:

[0023] 100, first passivation layer; 101, doped conductive layer; 102, tunnel dielectric layer; 103, substrate; 104, doped layer; 105, second passivation layer; 106, initial gate line; 107, gate; 108, sintering area; H1, predetermined distance. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme 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 part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

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

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

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

[0029] Step S201, providing a substrate, and sequentially performing texturing treatment, diffusion treatment, etching treatment, and front and back film deposition on the substrate to obtain a solar cell to be printed, wherein the solar cell to be printed includes two opposite surfaces;

[0030] In the process of making solar cells, the texturing treatment can remove the mechanical damage layer on the surface of the substrate, increase the surface area, reduce the reflectivity and remove impurities. The velvet structure formed after the texturing treatment can be a pyramid structure or an irregular concave-convex structure. The diffusion treatment can further form a PN junction on the substrate. For an N-type silicon substrate, a layer of phosphorus silicon glass is formed on the surface of the substrate during the diffusion process. 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 phosphorus silicon glass formed during the diffusion process to prevent the PN junction from short-circuiting. The front and back film deposition treatment is used to deposit a passivation film and an anti-reflection film on the front and back of the cell, thereby further improving the efficiency of the cell. For example, the front film layer can be made of silicon nitride material to reduce reflection and passivate the surface. The back film layer can be made of materials such as aluminum oxide and silicon nitride for passivation and reducing back recombination.

[0031] Figure 2 is a schematic diagram of the structure of a solar cell to be printed according to an embodiment of the present application, such as Figure 2As shown, 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. 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 may be an N-type substrate 103 or a P-type substrate 103. Moreover, in the thickness direction of the solar cell to be printed, both surfaces of the substrate 103 can be used to receive light. Further, the doped layer 104 and the second passivation layer 105 are sequentially arranged on the surface of one side of the substrate 103; the tunneling dielectric layer 102, the doped conductive layer 101, and the first passivation layer 100 are sequentially arranged on the surface of the other side of the substrate 103. In practical applications, the solar cells to be printed can constitute 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 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;

[0033] The printing slurry treatment can be carried out by at least one of screen printing, gravure printing, relief printing, flexographic printing, laser transfer, inkjet printing and 3D printing. The specific area of ​​the printing slurry can be set according to actual conditions, and this application does not make specific restrictions. Figure 3 is a schematic diagram of the structure of a solar cell to be sintered according to an embodiment of the present application, such as Figure 3 As shown, the paste is printed on the side of the second passivation layer 105 away from the doped layer 104 to obtain the initial gate line 106, and the position relationship of the remaining first passivation layer 100, doped conductive layer 101, tunnel dielectric layer 102 and substrate 103 is the same as Figure 2 The same as in, no further description is given here.

[0034] Step S203, performing multiple sintering treatments on each of the above-mentioned initial grid lines to form grid lines, wherein each of the above-mentioned sintering treatments forms a sintering area, and the orthographic projections of the multiple sintering areas on the above-mentioned solar cell to be sintered at least cover the orthographic projections of the above-mentioned initial grid lines on the above-mentioned 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 process refers to the process of making at least part of the slurry penetrate the corresponding part of the film layer structure on the substrate through heat treatment to form a grid line. In practical applications, the above-mentioned sintering process 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. The above-mentioned laser can be a linear laser emitted by a laser. In the process of continuous movement of the laser, the irradiation area formed by the linear light beam is the above-mentioned sintering area. In the process of the laser emitting laser, the emitter can emit continuously or at intervals.

[0036] Figure 4 is a schematic diagram of the structure of a solar cell according to an embodiment of the present application, such as Figure 4 As shown, the initial gate line is sintered, and part of the slurry burns through the second passivation layer 105 in the thickness direction of the substrate to form the gate 107. One end of the gate 107 contacts the doped layer 104 to form an ohmic contact, forming a tiny alloy junction, thereby reducing the contact resistance, which is beneficial to improving the transmission efficiency of electrons. The position relationship of the remaining first passivation layer 100, doped conductive layer 101, tunnel dielectric layer 102 and substrate 103 is the same as Figure 2 It should be noted that the moving direction ( Figure 5 The directions indicated by the arrows in the figure can be the same or opposite. The shapes of the sintering regions include but are not limited to rectangular, circular or elliptical shapes. In addition, the multiple sintering regions cover the initial grid lines, so as to achieve a good sintering effect.

[0037] In the above embodiment, a method for manufacturing a solar cell is provided, first, a substrate is provided, and the substrate is subjected to a texturing treatment, a diffusion treatment, an etching treatment, and a front and back film deposition in sequence to obtain a solar cell to be printed, wherein the solar cell to be printed includes two opposite surfaces; then, a slurry is printed on at least one surface of the solar cell to be printed to obtain a solar cell to be sintered, wherein the solar cell to be sintered includes a plurality of initial grid lines arranged at intervals; finally, each initial grid line is subjected to a plurality of sintering treatments to form a grid line, wherein each sintering treatment forms a sintering area, and the orthographic projections of the plurality of sintering areas 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 areas is greater than 0 and less than 8.4 mm 2In this scheme, after the solar cell is textured, diffused, etched, deposited on the front and back layers, and printed with slurry, and the solar cell to be sintered is obtained, the initial grid line is sintered multiple times, so that the next sintering process can sinter again to compensate for the incomplete sintering caused by the previous sintering process, thereby solving the problem of under-sintering in one sintering process; in addition, since multiple sintering areas obtained by multiple sintering processes can cover the initial grid line, and the overlapping area of ​​two adjacent sintering areas is greater than 0 and less than 8.4mm 2 On the basis of avoiding the problem of under-burning, the problem of over-burning can be further prevented, the sintering effect of solar cells can be improved, and the technical problem of unsatisfactory sintering effect of solar cells in the prior art is solved.

[0038] In the first direction, the minimum distance between the edge of the sintering area and the edge of the initial grid line is in the range of 0 to 400 μm, wherein the first direction is the direction in which the plurality of 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 from completely covering the grid line during the sintering process, further avoid the phenomenon of over-sintering caused by local overheating, and can accurately control the sintering area, avoid unnecessary energy waste, further improve sintering efficiency and reduce costs.

[0039] like Figure 5 As shown, the minimum distance between the edge of the sintering region 108 and the edge of the initial gate 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 region 108 and the edge of the initial gate line 106 can be 100μm, 200μm, 300μm and 400μm.

[0040] In the same grid line, the center points of two adjacent sintering regions have a spacing, and the spacing is greater than 0 and less than 0.5 mm. The above design can ensure proper separation between the center parts of the sintering regions, further avoid excessive fusion of the sintering regions, and further improve the sintering effect.

[0041] In this embodiment, the interval between the center points of two adjacent sintering regions in the same gate line may be any value, such as 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm.

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

[0043] In practical applications, among the multiple sintering regions formed on the same grid line, the minimum distances between the center points of the various sintering regions and the geometric center of the initial grid line may be the same or different, and those skilled in the art may set the same minimum distance or different minimum distances according to actual conditions. The minimum distance between the center point of any of the above sintering regions and the geometric center of the above initial grid line may 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 sintering processes is the same as the extending direction of the above grid lines. Since the laser is emitted by a laser, the moving direction of the above sintering process can be regarded as the moving direction of the laser. The moving direction of the above laser is the same as the extending direction of the grid lines. Compared with the method in which the moving direction of the laser intersects with the extending direction of the grid lines, a larger area on the grid lines can be sintered, thereby further improving the efficiency of the sintering process.

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

[0046] In some embodiments, the initial position of each of the above-mentioned sintering treatments is located at the same end of the above-mentioned initial grid line. During the laser processing process, as time goes by, due to the influence of thermal effects, changes in material surface transformation, and changes in processing accuracy and efficiency, the sintering effect will change significantly with time. In the early stage, it can usually improve the surface state of the material and the processing accuracy, but as time goes on, heat accumulation and energy overload may cause the surface quality of the material to deteriorate, the microstructure to deteriorate, and the processing efficiency to decrease. Therefore, the initial position of each of the above-mentioned sintering treatments is the same, which can ensure that the sintering effect of each sintering treatment is as similar as possible, ensure the uniformity of the sintering treatment of each sintering area, and further improve the sintering effect.

[0047] In some other embodiments, in the first direction, the maximum width of the sintering area ranges from 80 to 120 μm, wherein the first direction is the direction in which the plurality of initial grid lines are arranged. The setting of the maximum width of the sintering area can significantly reduce the heat-affected zone, minimize thermal deformation and residual stress during the sintering process, further avoid material damage caused by excessive heating, and further improve the sintering accuracy during the sintering process. In addition, the size setting of the sintering area can further accurately 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 sintering region may be any value within the above range. For example, the maximum width of the sintering region may be 80 μm, 90 μm, 100 μm, 110 μm and 120 μm.

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

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

[0051] In another embodiment of the present application, one of the above-mentioned sintering regions includes a plurality of sub-regions arranged along a second direction, and the center points of the above-mentioned sub-regions are located on the same straight line, wherein the above-mentioned second direction is the extension direction of the above-mentioned initial grid lines. In the case where the laser emits a beam at intervals, during the continuous movement of the laser, a plurality of sub-regions with intervals are formed, and the plurality of sub-regions constitute the above-mentioned sintering region. In other words, during the continuous movement of the laser, the above-mentioned arrangement can further improve the uniformity of the sintering effect by moving in a straight line along the extension direction of the initial grid lines.

[0052] The above-mentioned technical scheme of the present application can be used for full back electrode contact cells with busbar-free technology (0BB, Zero Busbar) or multi-busbar technology (MBB, MULTI-BUSBAR), full back electrode contact cells (IBC, Interdigitated Back Contact), full back contact cell solar cells (ABC, All Back Contact), composite passivated back contact cells (HPBC, Hybrid Passivated Back Contact), emitter back passivated cells (PERC, Passivated Emitter and Rear Cell), tunneling oxide passivated contact cells (TOPcon, Tnuuel Oxide Passivated contact), TOPcon-IBC cells, crystalline silicon heterojunction solar cells (HJT, Heterojunction with Intrinsic Thin-layer), perovskite stacked cells, flexible cells and other photovoltaic cells.

[0053] The embodiment of the present application further provides a solar cell as described above, wherein the solar cell is manufactured by any one of the above-mentioned methods for manufacturing a solar cell. Figure 4 As shown, the solar cell comprises:

[0054] A substrate 103, wherein the substrate 103 has a first surface and a second surface opposite to each other;

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

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

[0057] A tunnel dielectric layer 102 is disposed on the first surface, i.e., the back side of the substrate 103, so that the tunnel dielectric layer 102 has a chemical passivation effect on the back side of the substrate 103, specifically, by saturating the dangling bonds on the back side of the substrate 103, reducing the defect state density on the back side of the substrate 103, and reducing the recombination centers on the surface of the substrate 103 to reduce the carrier recombination rate. In some embodiments, the material of the tunnel dielectric layer 102 may include at least one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, and magnesium fluoride.

[0058] The doped conductive layer 101 is located on a side of the tunnel dielectric layer 102 away from the substrate 103;

[0059] The doped conductive layer 101 and the tunnel dielectric layer 102 constitute a passivation contact structure, which can form a band bending on the backlight surface of the substrate 103 to achieve selective transmission of carriers. 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 the same type of doping elements 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] A first passivation layer 100, located on a side of the doped conductive layer 101 away from the tunnel dielectric layer 102;

[0061] In practical applications, a PECVD method can be used to form a first passivation layer 100 on the side of the doped conductive layer 101 away from the tunnel dielectric layer 102. The first passivation layer 100 can play a good passivation role on the back side of the substrate 103, reduce the defect state density on the back side of the substrate 103, and better inhibit the carrier recombination on the back side 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] A doping layer 104, located on the second surface;

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

[0064] A second passivation layer 105, located on a side of the doping layer 104 away from the substrate 103;

[0065] The second passivation layer 105 can have a good anti-reflection effect, reduce the reflection of the incident light on the front side of the substrate 103, and improve the utilization rate of the 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 a surface of the second passivation layer 105 away from the doping layer 104 and is in contact with the doping layer 104 .

[0067] The gate electrode is manufactured by sintering the initial gate line, and partially burning the slurry through the second passivation layer 105 in the thickness direction of the substrate.

[0068] The solar cell in the above embodiment is manufactured by the above solar cell manufacturing method. In the manufacturing method, first, a substrate is provided, and the substrate is subjected to a texturing treatment, a diffusion treatment, an etching treatment, and a front and back film deposition in sequence to obtain a solar cell to be printed, wherein the solar cell to be printed includes two opposite surfaces; then, a slurry is printed on at least one surface of the solar cell to be printed to obtain a solar cell to be sintered, wherein the solar cell to be sintered includes a plurality of initial grid lines arranged at intervals; finally, each initial grid line is subjected to a plurality of sintering treatments to form a grid line, wherein each sintering treatment forms a sintering area, and the orthographic projections of the plurality of sintering areas 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 areas is greater than 0 and less than 8.4 mm 2 In this scheme, after the solar cell is textured, diffused, etched, deposited on the front and back layers, and printed with slurry, and the solar cell to be sintered is obtained, the initial grid line is sintered multiple times, so that the next sintering process can sinter again to compensate for the incomplete sintering caused by the previous sintering process, thereby solving the problem of under-sintering in one sintering process; in addition, since multiple sintering areas obtained by multiple sintering processes can cover the initial grid line, and the overlapping area of ​​two adjacent sintering areas is greater than 0 and less than 8.4mm 2 On the basis of avoiding the problem of under-burning, the problem of over-burning can be further prevented, the sintering effect of solar cells can be improved, and the technical problem of unsatisfactory sintering effect of solar cells in the prior art is solved.

[0069] The above-mentioned solar cell of the present application will be specifically described below in combination with specific embodiments and comparative examples.

[0070] Example

[0071] This embodiment provides a method for manufacturing a solar cell, comprising:

[0072] 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;

[0073] 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;

[0074] 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 .

[0075] Comparative Example

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

[0077] 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;

[0078] 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;

[0079] Each of the initial grid lines is subjected to a sintering process to form a grid line, wherein the orthographic projection of the sintered area formed by the sintering process 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.

[0080] The power of the solar cells manufactured in the above-mentioned embodiment and comparative example was tested using a digital source meter instrument. The test results are shown in Table 1.

[0081] Table 1

[0082]

[0083] Before the sintering process, both the comparative example and the embodiment are subjected to the steps of texturing, diffusion, etching, front and back film deposition, and printing slurry to obtain the solar cell to be sintered. The difference is that the comparative example is subjected to only one sintering process, and the sintered area formed completely covers the initial grid line, while the embodiment is subjected to multiple sintering processes, and the multiple sintered areas obtained cover the above-mentioned initial grid line, and the overlapping area of ​​two adjacent sintered areas is greater than 0 and less than 8.4 mm 2 From Table 1, it can be seen 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%. It can be seen that the method for manufacturing a solar cell provided in the embodiment of the present application improves the sintering effect while also improving the conversion efficiency of the solar cell.

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

[0085] 1. The method for manufacturing a solar cell of the present application comprises the following steps: first, providing a substrate, and sequentially performing a texturing treatment, a diffusion treatment, an etching treatment, and a front and back film deposition on the substrate to obtain a solar cell to be printed, wherein the solar cell to be printed comprises two opposite surfaces; then, printing a slurry on at least one surface 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; finally, performing a sintering treatment on each initial grid line for multiple times to form a grid line, wherein each sintering treatment forms a sintering region, and the orthographic projections of the plurality of 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 this scheme, after the solar cell is textured, diffused, etched, deposited on the front and back layers, and printed with slurry, and the solar cell to be sintered is obtained, the initial grid line is sintered multiple times, so that the next sintering process can sinter again to compensate for the incomplete sintering caused by the previous sintering process, thereby solving the problem of under-sintering in one sintering process; in addition, since multiple sintering areas obtained by multiple sintering processes can cover the initial grid line, and the overlapping area of ​​two adjacent sintering areas is greater than 0 and less than 8.4mm 2 On the basis of avoiding the problem of under-burning, the problem of over-burning can be further prevented, the sintering effect of solar cells can be improved, and the technical problem of unsatisfactory sintering effect of solar cells in the prior art is solved.

[0086] 2. The solar cell of the present application is manufactured by the above-mentioned solar cell manufacturing method. In the manufacturing method, first, a substrate is provided, and the substrate is subjected to a texturing treatment, a diffusion treatment, an etching treatment, and a front and back film deposition in sequence to obtain a solar cell to be printed, and the solar cell to be printed includes two opposite surfaces; then, a slurry 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 initial grid lines arranged at intervals; finally, each initial grid line is subjected to a plurality of sintering treatments to form a grid line, wherein each sintering treatment forms a sintering area, and the orthographic projections of the plurality of sintering areas 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 areas is greater than 0 and less than 8.4 mm 2In this scheme, after the solar cell is textured, diffused, etched, deposited on the front and back layers, and printed with slurry, and the solar cell to be sintered is obtained, the initial grid line is sintered multiple times, so that the next sintering process can sinter again to compensate for the incomplete sintering caused by the previous sintering process, thereby solving the problem of under-sintering in one sintering process; in addition, since multiple sintering areas obtained by multiple sintering processes can cover the initial grid line, and the overlapping area of ​​two adjacent sintering areas is greater than 0 and less than 8.4mm 2 On the basis of avoiding the problem of under-burning, the problem of over-burning can be further prevented, the sintering effect of solar cells can be improved, and the technical problem of unsatisfactory sintering effect of solar cells 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 .

2. The method for manufacturing a solar cell according to claim 1, characterized in that: 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.

3. 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.

4. 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.

5. 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.

6. 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.

7. 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.

8. 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.

9. 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.

10. 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 9.

Images