Method of cutting a silicon rod, silicon wafer, solar cell and photovoltaic module

Abstract

The present disclosure relates to a method for cutting a silicon rod, a silicon wafer, a solar cell and a photovoltaic module. The method comprises: providing a silicon rod; obtaining parameter information of the silicon rod at different positions in an extension direction, the parameter information comprising information of a minority carrier lifetime and information of an electrical resistivity of the silicon rod; dividing the silicon rod into a plurality of initial silicon wafer blocks arranged along the extension direction and having different parameter information according to the parameter information; and cutting the initial silicon wafer blocks to obtain silicon wafers. The uniformity of the quality of the silicon wafers is ensured, and the influence of the differences between the silicon wafers on solar cells is eliminated.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, and in particular to a method for cutting silicon rods, silicon wafers, solar cells, and photovoltaic modules. Background Technology

[0002] Silicon wafers for solar cells are cut from silicon rods. A typical method for preparing silicon wafers includes: squaring the silicon rod to obtain a central main silicon block and edge strips extending in the same direction as the silicon rod; cutting the central main silicon block along a cutting surface parallel or perpendicular to the direction of the silicon rod's extension; and cutting the edge strips along a cutting surface parallel to the direction of the silicon rod's extension to obtain silicon wafers. Since silicon rods are formed by melting silicon material at high temperatures and then pulling it into a crystalline silicon rod, there is a problem of uneven quality in silicon rods. Therefore, silicon wafers cut from the same silicon rod also have uneven quality, which in turn affects the performance of solar cells. Summary of the Invention

[0003] Based on this, a method for cutting silicon rods, silicon wafers, solar cells, and photovoltaic modules are provided, which can optimize the uniformity of silicon wafer quality and eliminate the impact of silicon wafer quality deviations on solar cell performance.

[0004] To achieve the above objectives, in one aspect, the present invention provides a method for cutting a silicon rod, comprising:

[0005] Silicon rods are supplied;

[0006] Obtain parameter information of the silicon rod at different positions in the extension direction, the parameter information including minority carrier lifetime information and resistivity information of the silicon rod;

[0007] Based on the parameter information, the silicon rod is divided into multiple initial silicon wafer blocks arranged along the extension direction and with different parameter information;

[0008] The initial silicon wafer block is cut to obtain silicon wafers.

[0009] In some embodiments, the step of slicing the initial silicon wafer includes:

[0010] The initial silicon wafer block is subjected to square root processing to obtain an initial main silicon block extending along the extension direction;

[0011] The initial silicon block is cut to obtain the silicon wafer.

[0012] In some embodiments, the initial bulk silicon block includes a first side extending along the extending direction, and cutting the initial bulk silicon block to obtain the silicon wafer includes:

[0013] The initial main silicon block is cut along a direction parallel to the first side to obtain the silicon wafer.

[0014] In some embodiments, the initial main silicon block further includes a second side extending along the extending direction and intersecting the first side, the first side including a first main side perpendicular to the second side, and cutting the initial main silicon block along a direction parallel to the first side, including:

[0015] According to the first preset size of the first side of the silicon wafer, the initial main silicon block is pre-cut in a direction parallel to the second side to obtain a transition main silicon block, wherein the first side of the silicon wafer is parallel to the first main side;

[0016] The transition body silicon block is cut along a direction parallel to the first side to obtain the silicon wafer.

[0017] In some embodiments, cutting the transition body silicon block along a direction parallel to the first side includes:

[0018] The first sides of the different transition body silicon blocks are bonded together to obtain a bonded body silicon block; or the second sides of the different transition body silicon blocks are bonded together to obtain a bonded body silicon block.

[0019] The bonding body silicon block is cut along a direction parallel to the first side surface;

[0020] Perform degumming treatment.

[0021] In some embodiments, the initial host silicon block further includes a host cross section perpendicular to the extension direction, and the step of obtaining the transition host silicon block further includes:

[0022] According to the second preset dimension of the second side of the silicon wafer, the initial main silicon block is pre-cut in a direction parallel to the main body cross section, wherein the second side is perpendicular to the first main body side.

[0023] In some embodiments, the step of pre-cutting the initial bulk silicon block along a direction parallel to the main cross-section further includes:

[0024] The initial main silicon block is pre-cut along a direction parallel to the main cross-section to obtain the transition main silicon block and the preset main silicon block;

[0025] The preset silicon block is cut along a direction parallel to the main body cross section to obtain a preset silicon wafer.

[0026] In some embodiments, the initial main silicon block further includes a main cross-section perpendicular to the extending direction, and the step of cutting the initial main silicon block to obtain the silicon wafer includes:

[0027] The initial silicon block is cut along a direction parallel to the main cross-section to obtain the silicon wafer.

[0028] In some embodiments, the initial bulk silicon block further includes a second side extending along the extending direction, the bulk cross-section including a first bulk side perpendicular to the second side, and the cutting of the initial bulk silicon block along a direction parallel to the bulk cross-section includes:

[0029] According to the first preset size of the first side of the silicon wafer, the initial main body silicon block is pre-cut in a direction parallel to the second side to obtain a transition main body silicon block, wherein the first side of the silicon wafer is parallel to the first main body side of the main body cross section;

[0030] The transition silicon block is cut along a direction parallel to the main cross-section to obtain the silicon wafer.

[0031] In some embodiments, cutting the transition body silicon block along a direction parallel to the main body cross-section includes:

[0032] The second sides of different transition body silicon blocks are bonded together to obtain a bonded body silicon block; or the first sides of different transition body silicon blocks are bonded together to obtain a bonded body silicon block, wherein the first side and the second side intersect and extend along the extension direction;

[0033] The bonding silicon block is cut along a direction parallel to the main cross-section;

[0034] Perform degumming treatment.

[0035] In some embodiments, the step of cutting the initial silicon wafer block further includes:

[0036] The initial silicon wafer block is subjected to a square root process to obtain edge material extending along the extension direction;

[0037] The edge material is cut to obtain an edge silicon block extending along the extension direction;

[0038] The edge silicon block is cut to obtain edge silicon wafers.

[0039] In some embodiments, the edge silicon block includes an edge side surface parallel to the extending direction, and cutting the edge silicon block to obtain an edge silicon wafer includes:

[0040] The edge silicon block is cut along a direction parallel to the side surface of the edge to obtain an edge silicon wafer.

[0041] In some embodiments, the dimension of the edge side perpendicular to the extending direction is equal to a first preset dimension of the first side of the silicon wafer, and the edge silicon block further includes an edge cross section perpendicular to the extending direction. Cutting the edge silicon block along a direction parallel to the edge side includes:

[0042] According to the second preset dimension of the second side of the silicon wafer, the edge silicon block is pre-cut along a direction parallel to the edge cross section to obtain an edge transition silicon block;

[0043] The edge transition silicon block is cut along a direction parallel to the side surface of the edge skin;

[0044] The second side of the silicon wafer is parallel to the extension direction.

[0045] A silicon wafer, said silicon wafer being manufactured by the cutting method of any of the preceding claims for cutting silicon rods.

[0046] A solar cell made of the aforementioned silicon wafer.

[0047] A photovoltaic module comprising a plurality of the aforementioned solar cells.

[0048] In the above-mentioned silicon rod cutting method, the silicon rod is divided into multiple initial silicon wafer blocks with different parameter information arranged along the extension direction according to the parameter information at different positions of the silicon rod in the extension direction. At this time, the parameter information at different positions of any initial silicon wafer block is the same. Then, the initial silicon wafer blocks are cut to obtain silicon wafers with good quality uniformity, which ensures the uniformity of silicon wafer quality, eliminates the influence of silicon wafer differences on solar cells, reduces the performance fluctuation of silicon wafers obtained by cutting silicon rods and solar cells made from silicon wafers, reduces sorting pressure, and saves costs. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a flowchart illustrating the silicon rod cutting method in some embodiments;

[0051] Figure 2 This is a schematic cross-sectional view of the silicon rod along the extension direction in some embodiments;

[0052] Figure 3 This is a top view of the initial silicon wafer block along the cross-sectional direction in some embodiments;

[0053] Figure 4 This is a schematic cross-sectional view of the initial main silicon block along the extension direction in one embodiment;

[0054] Figure 5 This is a schematic cross-sectional view of the initial bulk silicon block along the cross-sectional direction in some embodiments;

[0055] Figure 6 This is a top view of a silicon wafer in some embodiments;

[0056] Figure 7 This is a schematic cross-sectional view of the bonding body silicon block along the cross-sectional direction in one embodiment;

[0057] Figure 8 This is a schematic cross-sectional view of the initial main silicon block along the extension direction in some other embodiments;

[0058] Figure 9 This is a cross-sectional schematic diagram of the initial main silicon block along the extension direction in some other embodiments;

[0059] Figure 10 This is a schematic cross-sectional view of the edge material along the cross-sectional direction in some embodiments.

[0060] Explanation of reference numerals in the attached figures:

[0061] 100. Silicon rod; 102. Initial silicon wafer block; 104. Initial main silicon block; 106. Silicon wafer; 108. Transitional main silicon block; 110. Adhesive; 112. Pre-set main silicon block; 114. Edge silicon block; 202. First main side; 204. Edge skin material; 302. First side; 304. Second side. Detailed Implementation

[0062] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate preferred embodiments of the application. However, this application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0064] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, parts, regions, layers, doping types, and / or portions, these elements, parts, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, part, region, layer, doping type, or portion from another element, part, region, layer, doping type, or portion. Therefore, without departing from the teachings of this invention, the first element, component, region, layer, doping type, or portion discussed below may be represented as a second element, component, region, layer, or portion; for example, the first doping type may be referred to as the second doping type, and similarly, the second doping type may be referred to as the first doping type; the first doping type and the second doping type are different doping types, for example, the first doping type may be P-type and the second doping type may be N-type, or the first doping type may be N-type and the second doping type may be P-type.

[0065] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0066] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that when the terms “comprise” and / or “comprising” are used in this specification, the presence of the stated feature, integer, step, operation, element, and / or part is established, but the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or groups is not excluded. Meanwhile, when used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0067] Embodiments of the invention are described herein with reference to cross-sectional views illustrating ideal embodiments (and intermediate structures) of the invention, thus allowing for variations in the illustrated shape due to, for example, manufacturing techniques and / or tolerances. Therefore, embodiments of the invention should not be limited to the specific shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing techniques. For instance, implantation regions shown as rectangular typically have rounded or curved features at their edges and / or implantation concentration gradients, rather than a binary change from implantation regions to non-implantation regions. Similarly, the buried regions formed by implantation can result in some implantation in the region between the buried region and the surface traversed during implantation. Therefore, the regions shown in the figures are substantially schematic, and their shapes do not represent the actual shapes of regions of the device and do not limit the scope of the invention.

[0068] Figure 1 This is a flowchart illustrating the silicon rod cutting method in some embodiments. Figure 2 This is a schematic cross-sectional view of the silicon rod along its extension direction in some embodiments. Figure 2 In the diagram, the X direction represents the extension direction of the silicon rod, and the Y and Z directions are the first and second intersecting directions in the cross-section of the silicon rod, respectively. The plane containing the Z and Y directions is the cross-section, as shown below. Figure 1 , Figure 2 As shown, in this embodiment, a method for cutting a silicon rod is provided, including:

[0069] S102 provides silicon rods.

[0070] Specifically, a silicon rod 100 is provided after the single crystal pulling process. The size of the silicon rod 100 in the extension direction X is related to the time of single crystal pulling in the extension direction during the single crystal pulling process. The size of the cross-section of the silicon rod 100 in the Y and Z directions is related to the rotation speed and the moving speed in the extension direction of the silicon rod during the single crystal pulling process.

[0071] S104, Obtain parameter information of the silicon rod at different positions in the extension direction.

[0072] The parameter information of silicon rod 100 at different positions in the extension direction X is obtained. The parameter information includes minority carrier lifetime information and resistivity information of silicon rod 100. This disclosure does not limit the method of obtaining the parameter information.

[0073] S106, based on the parameter information, divide the silicon rod into multiple initial silicon wafer blocks arranged along the extension direction and with different parameter information.

[0074] Based on parameter information at different positions of the silicon rod 100, the silicon rod is divided into multiple initial silicon wafer blocks 102 arranged along the extension direction X. Different initial silicon wafer blocks 102 have different parameter information, while different positions within the same initial silicon wafer block 102 have the same parameter information. This method achieves differentiation of the quality uniformity of the subsequently obtained silicon wafers. Figure 2 As shown, the size of the initial silicon wafer 102 in the extension direction X is related to the distribution of parameter information. Different initial silicon wafers 102 can have the same or different sizes in the extension direction X.

[0075] S108, the initial silicon wafer block is cut to obtain silicon wafers.

[0076] Specifically, each initial silicon wafer block 102 is cut to obtain multiple silicon wafers. The cutting directions of different initial silicon wafer blocks 102 can be the same or different. In the extension direction X, different parts of the same initial silicon wafer block 102 can have different cutting directions. The cutting directions include vertical cuts along the direction parallel to the extension direction X (e.g., the cutting direction is parallel to the plane containing the Y and X directions, or the cutting direction is parallel to the plane containing the Z and X directions) and transverse cuts along the cross-sectional direction perpendicular to the extension direction (e.g., the cutting direction is parallel to the plane containing the Z and Y directions). It can be understood that in practical applications, an appropriate cutting direction is selected according to the size of the silicon wafer and the initial silicon wafer block 102.

[0077] In the above-mentioned silicon rod cutting method, based on the parameter information of the silicon rod 100 at different positions in the extension direction X, the silicon rod 100 is divided into initial silicon wafer blocks 102 arranged along the extension direction X. At this time, the parameter information of the initial silicon wafer blocks 102 at different positions is the same. Then, the initial silicon wafer blocks 102 are cut to obtain silicon wafers with good quality uniformity, which ensures the uniformity of silicon wafer quality, eliminates the influence of silicon wafer differences on solar cells, reduces the performance fluctuation of silicon wafers obtained by cutting the silicon rod 100 and solar cells made from silicon wafers, reduces sorting pressure, and saves costs.

[0078] Figure 3 This is a top view of the initial silicon wafer block along the cross-sectional direction in some embodiments, such as... Figure 3 As shown, in some embodiments, the step of cutting the initial silicon wafer block 102 includes steps S202-S204.

[0079] S202, the initial silicon wafer block 102 is subjected to square root processing to obtain an initial main silicon block 104 extending along the extension direction X.

[0080] S204, the initial main silicon block 104 is cut to obtain silicon wafers.

[0081] Steps S202-S204 specifically involve performing a square root operation on the initial silicon wafer 102 to obtain a cuboid initial main silicon block 104. Figure 3 The dashed lines indicate the cutting positions during the squaring process. For example, the cutting directions of the squaring process are along the directions of the first plane containing the X and Z directions, and the second plane containing the X and Y directions, with the first and second planes intersecting perpendicularly. Based on the preset dimensions of the silicon wafer and the diameter of the planes containing the Z and Y directions of the initial silicon wafer block 102, the lengths of the initial main silicon block 104 in the Z and Y directions are determined. For example, the diameter of the initial silicon wafer block 102 is 300 mm, and the preset dimensions of the silicon wafer are 210 mm * 105 mm. After the squaring process, the cross-section of the initial main silicon block 104 in the third plane containing the Z and Y directions has a side length of 210 mm. Then, the initial main silicon block 104 is cut to obtain silicon wafers. The parameter information within and between silicon wafers cut from the same initial main silicon block 104 is identical, resulting in good uniformity of silicon wafer quality, small performance fluctuations, and reduced silicon wafer sorting pressure.

[0082] Figure 4 This is a schematic cross-sectional view of the initial main silicon block along the extension direction in one embodiment, as shown below. Figure 4 As shown, in some embodiments, the initial main silicon block 104 includes a first side extending along the extension direction X. Cutting the initial main silicon block 104 to obtain the silicon wafer includes: cutting the initial main silicon block 104 along a direction parallel to the first side to obtain the silicon wafer 106. The first side can be a side of the initial main silicon block 104 in a first plane along the X and Z directions, or it can be a side of the initial main silicon block 104 in a second plane along the X and Y directions. For ease of description, the first side is exemplarily described below as the side of the initial main silicon block 104 in the first plane. Figure 4 The dashed lines on the initial main silicon block 104 are example cutting lines. For example, the dimension of the initial main silicon block 104 in the direction perpendicular to the first side is equal to a multiple of the silicon wafer thickness. When the initial main silicon block 104 is cut along the direction parallel to the first side, there is no excess silicon material. That is, the length L1 of the initial main silicon block 104 in the Y direction is M times the thickness D1 of the silicon wafer 106. When the initial main silicon block 104 is cut, it can be divided into M silicon wafers stacked in the Y direction, which can improve the utilization rate of the initial main silicon block 104 and reduce the production cost of the silicon wafer.

[0083] Figure 5 This is a schematic cross-sectional view of the initial bulk silicon block along a cross section in some embodiments. Figure 6 This is a top view of the silicon wafer in some embodiments, such as... Figure 5 , Figure 6 As shown, in some embodiments, the initial main silicon block 104 further includes a second side extending along the extension direction X and intersecting with the first side. The first side includes a first main body side 202 perpendicular to the second side. Cutting the initial main silicon block 104 in a direction parallel to the first side includes steps S302-S304.

[0084] S302, according to the first preset size of the first side 302 of the silicon wafer 106, the initial main body silicon block 104 is pre-cut in a direction parallel to the second side to obtain the transition main body silicon block 108, wherein the first side 302 of the silicon wafer 106 is parallel to the first main body side 202.

[0085] S304, the transition body silicon block 108 is cut along a direction parallel to the first side to obtain the silicon wafer 106.

[0086] Steps S302-S304 specifically involve the following steps: The first preset dimension of the first side 302 of the silicon wafer 106 is smaller than the dimension of the first main body side 202 of the initial main body silicon block 104. Based on the first preset dimension of the first side 302 of the silicon wafer 106, the initial main body silicon block 104 is pre-cut along a direction parallel to the second side (the pre-cut position is as follows). Figure 5 The initial main silicon block 104 is extended along the Y direction by a dashed line, resulting in several transition main silicon blocks 108 of the same size. At this time, the size of the first transition side obtained by cutting the first main side 202 in the transition main silicon block 108 is equal to the first preset size. Then, the transition main silicon block 108 is cut along a direction parallel to the first side (for example, the cutting position is as follows). Figure 5 The initial silicon block 104 is extended along the Z-direction by the dashed line, resulting in silicon wafer 106. This reduces the risk of cutting the initial silicon wafer, which has the same thickness as silicon wafer 106 but a larger size, into fragments of silicon wafer 106, simplifies the process flow, reduces the number of cutting steps, and lowers the manufacturing cost of silicon wafers.

[0087] Figure 7 This is a schematic cross-sectional view of the bonding body silicon block along the cross-sectional direction in one embodiment, as shown below. Figure 7 As shown, in some embodiments, the transition body silicon block 108 is cut along a direction parallel to the first side, including steps S402-S406.

[0088] S402, different transition main silicon blocks 108 are bonded together to obtain bonded main silicon blocks.

[0089] Specifically, in some embodiments, the first sides of different transition silicon blocks 108 are bonded together using adhesive to obtain a bonded silicon block. In this case, the transition silicon blocks 108 in the bonded silicon block are stacked in a direction perpendicular to the first side. When cutting the bonded silicon block in a direction parallel to the first side, the number of feeding operations when subsequently cutting the transition silicon blocks 108 to obtain silicon wafers 106 can be reduced, saving costs. In other embodiments, the second sides of different transition silicon blocks 108 are bonded together using adhesive (e.g., ...). Figure 7 As shown, a bonding silicon block is obtained. Subsequently, the bonding silicon block is cut along a direction parallel to the first side to obtain silicon wafer 106. At the same time, two transition silicon blocks 108 are cut, which reduces the number of cuts and lowers the manufacturing cost of silicon wafer 106.

[0090] S404, the bonding body silicon block is cut along a direction parallel to the first side to obtain silicon wafer 106.

[0091] S406 undergoes degumming treatment.

[0092] Specifically, a debonding process is performed to separate the bonded sides of the silicon wafers 106. Depending on the type of adhesive, methods such as immersion in chemical solvents, high temperature, or light irradiation can be used to remove the adhesive between the sides of the silicon wafers, thereby achieving the purpose of separating the silicon wafers 106.

[0093] Figure 8 This is a schematic cross-sectional view of the initial main silicon block along the extension direction in some other embodiments, such as... Figure 5 , Figure 6 , Figure 8 As shown, in some embodiments, the initial main silicon block 104 further includes a main cross section perpendicular to the extension direction X, that is, a cross section of the initial main silicon block 104 in the planes containing the Z and Y directions. The step of obtaining the transition main silicon block 108 further includes: according to the second preset size of the second side 304 of the silicon wafer 106, performing a number of pre-cuts on the initial main silicon block 104 in a direction parallel to the main cross section. The second side 304 is perpendicular to the first main side 202, that is, the second side 304 is parallel to the extension direction X. Through pre-cutting, the size of the transition main silicon block 108 in the extension direction X is equal to the size of the second side 304 of the silicon wafer 106, thereby obtaining a silicon wafer 106 with the required size.

[0094] like Figure 8 As shown, in some embodiments, the step of pre-cutting the initial main silicon block 104 along a direction parallel to the main body cross section further includes steps S502-S504.

[0095] S502, the initial main body silicon block 104 is pre-cut along a direction parallel to the main body cross section to obtain the transition main body silicon block 108 and the preset main body silicon block 112.

[0096] S504, the preset main silicon block 112 is cut along a direction parallel to the main cross section to obtain the preset silicon wafer.

[0097] Steps S502-S504 specifically involve pre-cutting the initial main silicon block 104 along a direction parallel to the main cross-section to obtain multiple transition main silicon blocks 108 of the same size and a preset main silicon block 112 of different size from the transition main silicon blocks 108. The transition main silicon blocks 108 are cut along a direction parallel to the first side or parallel to the second side to obtain silicon wafers 106. The cutting direction of the same transition main silicon block 108 is the same, while the cutting directions of different transition main silicon blocks 108 can be the same or different. The preset main silicon blocks 112 are cut along a direction perpendicular to the main cross-section to obtain preset silicon wafers. When the size of the preset cross-section of the preset main silicon block 112 perpendicular to the main cross-section is the same as the size of the silicon wafer 106, the size and performance of the preset silicon wafer and the silicon wafer 106 are the same. When the size of the preset cross-section of the preset main silicon block 112 perpendicular to the main cross-section is not the same as the size of the silicon wafer 106, the preset silicon wafer and the silicon wafer 106 only have the same performance. By cutting the preset main silicon block 112, a preset silicon wafer with the same performance and quality as the silicon wafer 106 can be obtained. In this way, while obtaining silicon wafers and preset silicon wafers with the same quality uniformity as the initial main silicon block 104, the utilization rate of silicon rod 100 is increased and the production cost of silicon wafer is reduced.

[0098] For example, in some other embodiments, the preset main silicon block 112 is cut along a direction parallel to the extension direction X to obtain a preset silicon wafer. When the preset main silicon block 112 and the transition main silicon block 108 are cut in the same direction, the preset main silicon block 112 and the transition main silicon block 108 can be bonded together and cut to obtain a preset silicon wafer and a silicon wafer 106, thereby reducing the number of steps in the silicon rod cutting method and saving costs.

[0099] Figure 9 This is a cross-sectional schematic diagram of the initial main silicon block along the extension direction in some other embodiments, such as... Figure 9 As shown, in some embodiments, the initial main silicon block 104 further includes a main cross-section perpendicular to the extending direction X. Here, the main cross-section is the cross-section of the initial main silicon block 104 in the planes containing the Z and Y directions. Cutting the initial main silicon block 104 to obtain the silicon wafer 106 includes: cutting the initial main silicon block 104 along a direction parallel to the main cross-section to obtain the silicon wafer 106. Figure 8 The dashed line along the Y direction is the cutting line.

[0100] like Figure 5 , Figure 6 , Figure 9 As shown, in some embodiments, the initial main silicon block 104 further includes a second side extending along the extension direction X. The main cross-section includes a first main side 202 perpendicular to the second side. Here, the first main side 202 is a common side of the first side and the main cross-section. The first side is the side of the initial main silicon block 104 that extends along the extension direction X and intersects with the second side. Cutting the initial main silicon block 104 along a direction parallel to the main cross-section includes steps S602-S604.

[0101] S602, according to the first preset size of the first side of the silicon wafer 106, the initial main body silicon block 104 is pre-cut in a direction parallel to the second side to obtain the transition main body silicon block 108, wherein the first side of the silicon wafer 106 is parallel to the first main body side 202 of the main body cross section.

[0102] S604, the transition main silicon block 108 is cut along a direction parallel to the main cross section to obtain the silicon wafer 106.

[0103] In some embodiments, cutting the transition body silicon block along a direction parallel to the body cross section includes steps S702-S706.

[0104] S702, different transition main silicon blocks 108 are bonded together to obtain bonded main silicon blocks.

[0105] Specifically, in some embodiments, the first sides of different transition silicon blocks 108 are bonded together using adhesive to obtain a bonded silicon block. In this case, the transition silicon blocks 108 within the bonded silicon block are stacked in a direction perpendicular to the first side. Subsequently, when the bonded silicon block is cut along a direction parallel to the cross-section of the main body to obtain the silicon wafer 106, two transition silicon blocks 108 are cut simultaneously, reducing the number of cuts and lowering the manufacturing cost of the silicon wafer. In other embodiments, the second sides of different transition silicon blocks 108 are bonded together using adhesive (e.g., ...). Figure 7 As shown, a bonding main silicon block is obtained. Subsequently, the bonding main silicon block is cut along a direction parallel to the main cross section to obtain silicon wafer 106. At the same time, two transition main silicon blocks 108 can be cut simultaneously, reducing the number of cuts and lowering the manufacturing cost of silicon wafer 106.

[0106] S704, the bonding silicon block is cut along a direction parallel to the cross-section of the main body to obtain silicon wafer 106.

[0107] S706 undergoes degumming treatment.

[0108] Figure 10 This is a schematic cross-sectional view of the edge material along the cross-sectional direction in some embodiments, such as... Figure 3 , Figure 10 As shown, in some embodiments, the step of cutting the initial silicon wafer block 102 further includes steps S802-S806.

[0109] S802, the initial silicon wafer block 102 is subjected to square root processing to obtain edge material 204 extending along the extension direction X.

[0110] S804, the edge material 204 is cut to obtain an edge silicon block 114 extending along the extension direction X.

[0111] S806, the edge silicon block 114 is cut to obtain the edge silicon wafer.

[0112] Steps S802-S806 specifically involve: squaring the initial silicon wafer block 102 to obtain an initial main silicon block 108 and four edge pieces 204 with the sides of the initial main silicon block 108 as their bottom surfaces; then cutting the edge pieces 204 to obtain edge silicon blocks 114 extending along the extension direction X. For example, the edge pieces 204 are cut along cutting directions parallel to and perpendicular to the bottom surfaces of the edge pieces 204 to obtain edge silicon blocks 114 extending along the extension direction X. The resulting edge silicon wafers 114 are cuboids. At this point, the utilization rate of the silicon rod 100 is highest, and subsequent cutting of the edge silicon blocks 114 yields edge silicon wafers of the same size. Then, the edge silicon blocks 114 are cut to obtain the edge silicon wafers. By processing the edge material 202, edge silicon wafers with the same parameter information (minority carrier lifetime and resistivity) as silicon wafers 106 (preset silicon wafers) cut from the initial main silicon block 104 are obtained, which improves the utilization rate of silicon rod 100. Subsequently, edge silicon wafers and silicon wafers (preset silicon wafers) can be used to prepare solar cells with the same performance, reducing the manufacturing cost of solar cells.

[0113] In some embodiments, the edge silicon block 114 includes an edge side surface parallel to the extending direction X. Cutting the edge silicon block 114 to obtain an edge silicon wafer includes cutting the edge silicon block 114 along a direction parallel to the edge side surface to obtain the edge silicon wafer. It is understood that the edge side surface includes a first edge side surface parallel to the bottom surface of the edge material 204 and a second edge side surface perpendicular to the bottom surface of the edge material 204. A suitable cutting direction can be selected from the first and second edge side surfaces as needed. Further, cutting the edge silicon block 114 along a direction parallel to the first edge side surface yields a larger edge silicon wafer.

[0114] In some embodiments, the dimension of the edge side perpendicular to the extension direction X is equal to the first preset dimension of the first side of the silicon wafer. For example, the edge side is the side of the first edge side perpendicular to the extension direction X. The edge silicon block 114 also includes an edge cross-section perpendicular to the extension direction X. Cutting the edge silicon block 114 along a direction parallel to the edge side includes: pre-cutting the edge silicon block 114 along a direction parallel to the edge cross-section according to the second preset dimension of the second side of the silicon wafer to obtain an edge transition silicon block; and cutting the edge transition silicon block along a direction parallel to the edge side. The second side of the silicon wafer is parallel to the extension direction X. This method can obtain an edge silicon wafer with the same dimensions as the silicon wafer. Further, the length of the edge side perpendicular to the extension direction X of the first edge side of the edge silicon block 114 is half the length of the corresponding initial main silicon block side. This setting can obtain silicon wafers and edge silicon wafers of the same dimensions.

[0115] In some embodiments, the edge silicon blocks 114 can be bonded together for cutting, thereby improving cutting efficiency. For details, please refer to the above description of bonding different transition body silicon blocks 108 together for cutting, which will not be repeated here.

[0116] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.

[0117] This disclosure also provides a silicon wafer manufactured by the cutting method of any of the preceding claims for silicon rods.

[0118] This disclosure also provides a solar cell made of the aforementioned silicon wafer.

[0119] This disclosure also provides a photovoltaic module comprising a plurality of the aforementioned solar cells.

[0120] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0121] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for cutting a silicon rod, characterized in that, include: Silicon rods are supplied; Obtain parameter information of the silicon rod at different positions in the extension direction, the parameter information including minority carrier lifetime information and resistivity information of the silicon rod; Based on the parameter information, the silicon rod is divided into multiple initial silicon wafer blocks arranged along the extension direction and with different parameter information. The parameter information is the same at different positions within the same initial silicon wafer block. The initial silicon wafer block is cut to obtain silicon wafers.

2. The method for cutting silicon rods according to claim 1, characterized in that, The step of cutting the initial silicon wafer block includes: The initial silicon wafer block is subjected to square root processing to obtain an initial main silicon block extending along the extension direction; The initial silicon block is cut to obtain the silicon wafer.

3. The method for cutting silicon rods according to claim 2, characterized in that, The initial main silicon block includes a first side extending along the extending direction, and the step of cutting the initial main silicon block to obtain the silicon wafer includes: The initial main silicon block is cut along a direction parallel to the first side to obtain the silicon wafer.

4. The method for cutting silicon rods according to claim 3, characterized in that, The initial main silicon block further includes a second side extending along the extending direction and intersecting the first side, the first side including a first main side perpendicular to the second side, and cutting the initial main silicon block along a direction parallel to the first side, including: According to the first preset size of the first side of the silicon wafer, the initial main silicon block is pre-cut in a direction parallel to the second side to obtain a transition main silicon block, wherein the first side of the silicon wafer is parallel to the first main side; The transition body silicon block is cut along a direction parallel to the first side to obtain the silicon wafer.

5. The method for cutting silicon rods according to claim 4, characterized in that, The step of cutting the transition body silicon block along a direction parallel to the first side includes: The first sides of the different transition body silicon blocks are bonded together to obtain a bonded body silicon block; or the second sides of the different transition body silicon blocks are bonded together to obtain a bonded body silicon block. The bonding body silicon block is cut along a direction parallel to the first side surface; Perform degumming treatment.

6. The method for cutting silicon rods according to claim 4, characterized in that, The initial main silicon block also includes a main cross section perpendicular to the extension direction, and the step of obtaining the transition main silicon block further includes: According to the second preset dimension of the second side of the silicon wafer, the initial main silicon block is pre-cut in a direction parallel to the main body cross section, wherein the second side is perpendicular to the first main body side.

7. The method for cutting silicon rods according to claim 6, characterized in that, The step of pre-cutting the initial main silicon block along a direction parallel to the main cross-section further includes: The initial main silicon block is pre-cut along a direction parallel to the main cross-section to obtain the transition main silicon block and the preset main silicon block; The preset silicon block is cut along a direction parallel to the main body cross section to obtain a preset silicon wafer.

8. The method for cutting silicon rods according to claim 2, characterized in that, The initial main silicon block also includes a main cross-section perpendicular to the extending direction, and the step of cutting the initial main silicon block to obtain the silicon wafer includes: The initial silicon block is cut along a direction parallel to the main cross-section to obtain the silicon wafer.

9. The method for cutting silicon rods according to claim 8, characterized in that, The initial main silicon block further includes a second side extending along the extending direction, and the main cross-section includes a first main side perpendicular to the second side. Cutting the initial main silicon block along a direction parallel to the main cross-section includes: According to the first preset size of the first side of the silicon wafer, the initial main body silicon block is pre-cut in a direction parallel to the second side to obtain a transition main body silicon block, wherein the first side of the silicon wafer is parallel to the first main body side of the main body cross section; The transition silicon block is cut along a direction parallel to the main cross-section to obtain the silicon wafer.

10. The method for cutting a silicon rod according to claim 9, characterized in that, The step of cutting the transition silicon block along a direction parallel to the main cross-section includes: The second sides of different transition body silicon blocks are bonded together to obtain a bonded body silicon block; or the first sides of different transition body silicon blocks are bonded together to obtain a bonded body silicon block, wherein the first side and the second side intersect and extend along the extension direction; The bonding silicon block is cut along a direction parallel to the main cross-section; Perform degumming treatment.

11. The method for cutting silicon rods according to claim 2, characterized in that, The step of cutting the initial silicon wafer block further includes: The initial silicon wafer block is subjected to a square root process to obtain edge material extending along the extension direction; The edge material is cut to obtain an edge silicon block extending along the extension direction; The edge silicon block is cut to obtain edge silicon wafers.

12. The method for cutting silicon rods according to claim 11, characterized in that, The edge silicon block includes an edge side surface parallel to the extending direction. Cutting the edge silicon block to obtain an edge silicon wafer includes: The edge silicon block is cut along a direction parallel to the side surface of the edge to obtain an edge silicon wafer.

13. The method for cutting a silicon rod according to claim 12, characterized in that, The dimension of the edge side perpendicular to the extending direction is equal to the first preset dimension of the first side of the silicon wafer. The edge silicon block also includes an edge cross section perpendicular to the extending direction. Cutting the edge silicon block along a direction parallel to the edge side includes: According to the second preset dimension of the second side of the silicon wafer, the edge silicon block is pre-cut along a direction parallel to the edge cross section to obtain an edge transition silicon block; The edge transition silicon block is cut along a direction parallel to the side surface of the edge skin; The second side of the silicon wafer is parallel to the extension direction.

14. A silicon wafer, characterized in that, The silicon wafer is manufactured by the cutting method of the silicon rod according to any one of claims 1-13.

15. A solar cell, characterized in that, The solar cell is made of the silicon wafer as described in claim 14.

16. A photovoltaic module, characterized in that, Includes several solar cells as described in claim 15.

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