Solar cell, photovoltaic module, photovoltaic system and printing screen

Abstract

The invention is suitable for the technical field of batteries, and provides a solar battery, a photovoltaic module, a photovoltaic system and a printing screen printing plate, the solar battery comprises a silicon substrate and a plurality of auxiliary grids, and the plurality of auxiliary grids comprise two kinds of auxiliary grids with different polarities; the plurality of auxiliary grids are arranged on the silicon substrate and extend along a first direction, two kinds of auxiliary grids with different polarities are alternately arranged at intervals along a second direction, and the first direction and the second direction are crossed; in the plurality of auxiliary grids, the distances between the first auxiliary grid and the second auxiliary grid and between the first auxiliary grid and the third auxiliary grid are not equal; the second auxiliary grid and the third auxiliary grid are adjacent to the first auxiliary grid and are different from the first auxiliary grid in grid performance; in the auxiliary grid with the same grid polarity as the first auxiliary grid, the distance between the first auxiliary grid and the fourth auxiliary grid and the distance between the first auxiliary grid and the fifth auxiliary grid are not equal, and the fourth auxiliary grid and the fifth auxiliary grid are adjacent to the first auxiliary grid. According to the solar cell, the photovoltaic module, the photovoltaic system and the printing screen provided by the invention, the problem of grid breakage can be reduced, and the product yield of the solar cell is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of batteries, and in particular relates to a solar cell, a photovoltaic module, a photovoltaic system and a printing screen. Background Art

[0002] In the related art, the printing screen is composed of a mesh of different mesh sizes woven from stainless steel wire, latex coated on the mesh, and a mesh frame supporting the mesh. The latex is removed at the opening of the printed pattern, so that when the scraper brushes over the mesh, the slurry applied on the screen passes through the opening of the printed pattern and is printed on the substrate. Due to the presence of mesh knots on the screen, the mesh knots may block the flow of the slurry, resulting in uneven printing lines or breakpoints. As a result, the printed pattern corresponding to part of the sub-grid may coincide with the mesh knot, resulting in a break when printing part of the sub-grid. Summary of the invention

[0003] The invention provides a solar cell, a photovoltaic module, a photovoltaic system and a printing screen, aiming to solve the problem that the printed auxiliary grid is prone to grid breakage.

[0004] The present invention provides a solar cell, comprising: a silicon substrate and a plurality of auxiliary grids, wherein the plurality of auxiliary grids include two types of auxiliary grids with different polarities;

[0005] The plurality of auxiliary gates are arranged on the silicon substrate and extend along a first direction, the two types of auxiliary gates with different polarities are alternately arranged along a second direction, and the first direction intersects with the second direction;

[0006] Among the plurality of sub-grids, the first sub-grid has unequal spacings from the second sub-grid and the third sub-grid; the second sub-grid and the third sub-grid are both adjacent to the first sub-grid and have different properties from the first sub-grid;

[0007] In the auxiliary grid having the same characteristics as the first auxiliary grid, the first auxiliary grid has unequal intervals with the fourth auxiliary grid and the fifth auxiliary grid, and the fourth auxiliary grid and the fifth auxiliary grid are both adjacent to the first auxiliary grid.

[0008] In some embodiments, the interval between two adjacent sub-grids of the same polarity is adjusted based on the mesh size of the printing screen corresponding to the sub-grids of the same polarity.

[0009] In some embodiments, the plurality of sub-grids include a first sub-grid and a second sub-grid having different polarities;

[0010] The intervals between two adjacent auxiliary grids in the at least one group of auxiliary grids are not equal, which includes at least one of the following situations:

[0011] The first auxiliary grid and the two second auxiliary grids adjacent to the first auxiliary grid are not spaced apart from each other;

[0012] The second sub-grid and the two first sub-grids adjacent to the second sub-grid are not spaced apart from each other.

[0013] In some embodiments, the mesh size is A μm, the initial spacing between two adjacent sub-grids of the same polarity is B mm; the two adjacent sub-grids of the same polarity include a target sub-grid, and the target sub-grid is a sub-grid of the mesh of the printing screen where the printed pattern corresponding to the plurality of sub-grids contacts;

[0014] The adjustment range of the distance between two adjacent auxiliary grids of the auxiliary grids with the same polarity is greater than (BA) mm and less than (B+A) mm.

[0015] In some embodiments, the mesh size is 40 μm to 50 μm.

[0016] In some embodiments, the initial distance between two adjacent sub-grids of the sub-grids with the same polarity is 0.9 mm to 1.1 mm.

[0017] In some embodiments, a line width of the first secondary gate is less than 33 μm.

[0018] In some embodiments, the line width of the second sub-gate is less than 30 μm.

[0019] The present invention also provides a photovoltaic assembly, comprising: a solar cell as described in any one of the above items.

[0020] The present invention also provides a photovoltaic system, comprising: the photovoltaic module as described above.

[0021] The present invention also provides a printing screen, comprising: a screen frame, a mesh cloth and a plurality of printing patterns corresponding to sub-grids, the mesh cloth being fixed on the screen frame, and the printing pattern being located on the mesh cloth; the mesh cloth being interwoven with warp and weft threads, the warp and weft threads intersecting to form a plurality of mesh knots; the printing pattern does not pass through the plurality of mesh knots.

[0022] The solar cell, photovoltaic module, photovoltaic system and printing screen provided by the present invention adjust the spacing of the auxiliary grids so that the auxiliary grids can avoid the mesh knots when the grid lines are printed, so that after the printing is completed, among the multiple auxiliary grids arranged on the silicon substrate, there is at least one first auxiliary grid whose spacings are unequal to those of the second auxiliary grid and the third auxiliary grid adjacent to it, and there is also at least one first auxiliary grid whose spacings are unequal to those of the fourth auxiliary grid and the fifth auxiliary grid adjacent to it and having the same polarity, so that the problem of broken grids can be reduced and the product yield of the solar cell can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is one of the structural schematic diagrams of a solar cell provided by an embodiment of the present invention;

[0024] Figure 2 is a schematic diagram of the structure of a network knot provided by an embodiment of the present invention;

[0025] Figure 3 This is the second structural schematic diagram of the solar cell provided by the embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of the structure of a printed graphic provided by an embodiment of the present invention;

[0027] Figure 5 is a schematic structural diagram of a photovoltaic assembly provided by an embodiment of the present invention;

[0028] Figure 6 is a schematic structural diagram of a photovoltaic system provided by an embodiment of the present invention;

[0029] Figure 7 It is a schematic diagram of the structure of a printing screen provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] Reference to "embodiments" or "implementations" in the present invention means that the specific features, components, or characteristics described in conjunction with the embodiments or implementations may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0032] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] Combine the following Figures 1 to 7 , the solar cell, photovoltaic module, photovoltaic system and printing screen provided by the embodiments of the present invention are described in detail through specific embodiments and their application scenarios.

[0035] Figure 1 FIG. 1 is one of the structural schematic diagrams of the solar cell provided by the embodiment of the present invention. Figure 1 As shown, the present invention provides a solar cell, comprising: a silicon substrate 10 and a plurality of auxiliary grids 20, wherein the plurality of auxiliary grids 20 include two types of auxiliary grids 20 with different polarities;

[0036] A plurality of auxiliary gates 20 are disposed on the silicon substrate 10 and extend along a first direction, and two types of auxiliary gates 20 with different polarities are alternately arranged along a second direction, and the first direction intersects the second direction;

[0037] The spacing between at least one auxiliary grid 20 and two adjacent auxiliary grids 20 having the same polarity is unequal;

[0038] The intervals between two adjacent auxiliary grids 20 in at least one group of auxiliary grids 20 are not equal, and each group of auxiliary grids 20 includes three auxiliary grids 20 arranged continuously.

[0039] Among the plurality of sub-grids 20, the first sub-grid 201 is not spaced from the second sub-grid 202 and the third sub-grid 203, and the second sub-grid 202 and the third sub-grid 203 are both adjacent to the first sub-grid 201 and have different polarities from the first sub-grid 201;

[0040] In the auxiliary grid 20 with the same polarity as the first auxiliary grid 201 , the first auxiliary grid 201 is not spaced equally from the fourth auxiliary grid 204 and the fifth auxiliary grid 205 , and both the fourth auxiliary grid 204 and the fifth auxiliary grid 205 are adjacent to the first auxiliary grid 201 .

[0041] In the embodiment of the present invention, the solar cell can be a busbar-free solar cell or a busbar-equipped solar cell, and the silicon substrate 10 included in the solar cell can be a whole cell, or a half cell, a third cell, or a cell of other proportions divided from a whole cell. It should be noted that the drawings provided in the embodiment of the present invention are schematic diagrams and do not limit the specific form of the solar cell.

[0042] Further, the silicon substrate 10 includes two opposite surfaces, including a light-receiving surface facing the sun, the light-receiving surface mainly receives direct sunlight, and a backlight surface facing the mounting surface of the photovoltaic module, mainly receiving sunlight reflected by the mounting surface, and the mounting surface is, for example, the ground, the roof, etc. The light-receiving surface or the backlight surface of the silicon substrate 10 can be provided with a sub-grid 20. In addition, the surface of the silicon substrate 10 on which the sub-grid 20 is provided also includes a doping layer and a passivation layer that are stacked, and the doping layer can be connected to the sub-grid 20 to establish an ohmic contact.

[0043] The plurality of auxiliary grids 20 include two types of auxiliary grids 20 with different polarities, for example, a positive auxiliary grid and a negative auxiliary grid. The plurality of auxiliary grids 20 extend along a first direction, and the two types of auxiliary grids 20 with different polarities are alternately arranged along a second direction, and the second direction intersects the first direction. The first direction may be the length direction of the auxiliary grid 20, i.e. Figure 1 The second direction may be specifically the width direction of the secondary grid 20, that is, Figure 1 Of course, in other embodiments, the first direction and the second direction may also be other directions, such as diagonal directions, etc., which are not specifically limited here.

[0044] In a solar cell with a main grid, a main grid can be provided on the front or back of the silicon substrate 10, and the main grid is used to collect the current on the auxiliary grid 20 and conduct it to the outside of the cell. In a solar cell without a main grid, a welding strip can be used on the back of the cell 10 to collect the current collected by the auxiliary grid 20.

[0045] In the embodiment of the present invention, the plurality of auxiliary grids 20 are arranged at non-equidistant intervals in the second direction. Figure 1 The several auxiliary grids 20 may be auxiliary grids 20 in the whole battery cell, or auxiliary grids 20 in a local area of ​​the whole battery cell, or auxiliary grids 20 in a half-cell, a third-cell, or other proportions of a battery cell 10 divided from a whole battery cell, and are not specifically limited here.

[0046] In the related art, the order of printing grid lines of solar cells is: the first screen prints the main grid, and the second and third screens respectively print two types of sub-grids with different polarities.

[0047] Several sub-grids are arranged at equal intervals, and the printing pattern of a single printing screen is used to print sub-grids of the same polarity. Figure 2As shown, the screen is made of warp and weft yarns interwoven according to a certain pattern. During the interweaving process, the yarns will form nodes at the intersections, and these nodes are the mesh knots 30. The printed graphics corresponding to the sub-grids of the same polarity are also arranged in parallel with equal spacing, and the extension direction of the printed graphics corresponding to the sub-grids is parallel to the yarns of the printed screen. Under this arrangement, the printed graphics corresponding to some sub-grids may cover the yarns where the mesh knots 30 are located or contact at least part of the area corresponding to the mesh knots 30, and then the mesh knots 30 may block the flow of the slurry, resulting in a broken grid in the sub-grid printed at the mesh knots.

[0048] In the embodiment of the present invention, the position of the printed pattern corresponding to this part of the auxiliary grid can be adjusted so that this part of the auxiliary grid avoids the mesh knot, so that at least one auxiliary grid 20 and its two adjacent auxiliary grids 20 with the same polarity have unequal spacing on the silicon substrate 10.

[0049] It should be noted that, in the embodiment of the present invention, the spacing between the auxiliary grids refers to the distance between two opposite edges of two auxiliary grids.

[0050] like Figure 1 As shown, the plurality of sub-grids 20 include a first sub-grid 201 , a second sub-grid 202 , a third sub-grid 203 , a fourth sub-grid 204 and a fifth sub-grid 205 .

[0051] Among the plurality of sub-gates 20 , the second sub-gate 202 and the third sub-gate 203 are two sub-gates 20 adjacent to the first sub-gate 201 and having different polarities from the first sub-gate 201 ; the fourth sub-gate 204 and the fifth sub-gate 205 are two sub-gates 20 adjacent to the first sub-gate 201 among the sub-gates 20 having the same polarity as the first sub-gate 201 .

[0052] The second sub-gate 202 is disposed between the first sub-gate 201 and the fourth sub-gate 204 , and the third sub-gate 203 is disposed between the first sub-gate 201 and the fifth sub-gate 205 .

[0053] Among the auxiliary grids 20 of the same polarity arranged along the second direction, the spacing between two adjacent auxiliary grids 20 of the same polarity may be equal or unequal. The spacing between two adjacent auxiliary grids 20 of the same polarity may be the spacing D1 between the first auxiliary grid 201 and the fifth auxiliary grid 205, or the spacing D3 between the first auxiliary grid 201 and the fourth auxiliary grid 204, wherein D1 is greater than D3. The spacing between two adjacent auxiliary grids 20 of the same polarity may also be the spacing D2, wherein D1 is greater than D2, and D2 is greater than D3.

[0054] In the auxiliary gate 20 with the same polarity as the first auxiliary gate 201, the distance between two adjacent auxiliary gates 20 with the same polarity can also be D7 and D8, wherein D7 is equal to D8, and D2 is equal to D7.

[0055] It should be noted that when two spacings are compared, the two spacings can be considered equal when the absolute value of the difference between the two spacings is less than 0.05 mm.

[0056] In the auxiliary gate 20 with different polarity from the first auxiliary gate 201, the distance between two adjacent auxiliary gates 20 with the same polarity can also be D4 and D9, wherein D4 is smaller than D9.

[0057] In the auxiliary gate 20 with different polarity from the first auxiliary gate 201, the distance between two adjacent auxiliary gates 20 with the same polarity can also be D5 and D6, wherein D5 is equal to D6, D4 is smaller than D5, and D5 is smaller than D9.

[0058] Among the plurality of sub-grids 20 arranged along the second direction, the intervals between two adjacent sub-grids 20 may be equal or unequal, and the intervals between the middle sub-grid 20 and the two adjacent sub-grids 20 among the three sub-grids 20 arranged continuously at intervals among the plurality of sub-grids 20 may be the intervals between the first sub-grid 201 and the second sub-grid 202, or may be the interval d1 between the first sub-grid 201 and the interval d2 between the third sub-grid 203. Among them, d1 is smaller than d2, d1 is smaller than d3, and d3 is smaller than d2.

[0059] The distance between two adjacent auxiliary gates 20 may also be d3, d4, d5, d6 or d7, wherein d6 is greater than d7, d6 is greater than d5, d5 is greater than d7, and d3 is equal to d4, and d4 is equal to d5.

[0060] In the solar cell provided by the embodiment of the present invention, in order to avoid the mesh knot on the printed screen, among the several sub-grids arranged on the silicon substrate, there is at least one group of sub-grids with unequal spacing between two adjacent sub-grids, and there is also at least one sub-grid with the same polarity and two adjacent sub-grids with unequal spacing, so that by adjusting the spacing of the sub-grids, the possibility of the sub-grids overlapping with the mesh knots can be reduced, thereby reducing the problem of broken grids and improving the product yield of the solar cell.

[0061] In some embodiments, the interval between two adjacent sub-grids 20 of the same polarity is adjusted based on the mesh size of the printing screen corresponding to the plurality of sub-grids 20 .

[0062] In actual implementation, the printed pattern corresponding to the auxiliary grid 20 is between two adjacent parallel yarns to avoid falling on the mesh knot 30. Therefore, the mesh size determines the position adjustment range of the printed pattern corresponding to the auxiliary grid 20, and further determines the spacing between two adjacent auxiliary grids 20 of the same polarity. Among them, the mesh size refers to the distance between two adjacent mesh knots 30 or two adjacent mesh wires in the screen.

[0063] It can be understood that, the larger the mesh size, the larger the position adjustment range of the printed pattern corresponding to the auxiliary grid 20, and the larger the spacing range between two adjacent auxiliary grids 20 of the same polarity.

[0064] For example: the mesh size is 50μm, and the spacing between two adjacent sub-grids 20 of the same polarity is 1mm. If a sub-grid 20 covers the yarn where the mesh knot 30 is located or contacts at least a partial area corresponding to the mesh knot 30, then the sub-grid 20 is translated along the second direction, and the spacing adjustment range is greater than 0.95mm and less than 1.05mm.

[0065] In some embodiments, the mesh size is A μm, and the initial spacing between two adjacent sub-grids 20 of the same polarity is B mm; two adjacent sub-grids 20 of the same polarity include a target sub-grid 201, and the target sub-grid 201 is a sub-grid whose mesh of the printed pattern corresponding to a plurality of sub-grids 20 covers the printed screen;

[0066] The adjustment range of the interval between two adjacent auxiliary grids 20 of the same polarity is greater than (BA) mm and less than (B+A) mm.

[0067] like Figure 3 As shown, taking the first sub-grid 201 and the fourth sub-grid 204 as examples, the first sub-grid 201 is the target sub-grid 201 in the embodiment of the present invention, the fourth sub-grid 204 is the non-target sub-grid 204, and the target sub-grid 201 and the non-target sub-grid 204 are two adjacent sub-grids 20 of the same polarity. Before adjusting the position of the printed pattern corresponding to the target sub-grid 201, the two adjacent sub-grids 20 are the target sub-grid 201 and the non-target sub-grid 204, the target sub-grid 201 is in contact with the yarn corresponding to the mesh knot 30, and the non-target sub-grid 204 is not in contact with the yarn corresponding to the mesh knot 30.

[0068] The initial spacing between two adjacent auxiliary grids 20 with the same polarity is B mm, the mesh size is A μm, and the printed pattern corresponding to the target auxiliary grid 201 can be translated by A μm on both sides in the second direction, such as Figure 4 As shown, the target sub-grid 201 is translated upward for a distance, so as to avoid the yarn corresponding to the knot 30 on the screen. The spacing adjustment range of two adjacent sub-grids 20 with the same polarity is greater than (BA) mm and less than (B+A) mm. Among them, the printed pattern is a pattern located on the printing screen for printing the sub-grid 20 with the same polarity as the first sub-grid 201.

[0069] In some embodiments, the mesh size is 40 μm to 50 μm.

[0070] Optionally, when A is equal to 40, the mesh size is 40 μm. Assuming that the initial spacing between two adjacent sub-grids 20 with the same polarity is 1 mm, when the two adjacent sub-grids 20 cover the yarn corresponding to the mesh knot 30 or contact at least a partial area corresponding to the mesh knot 30, the spacing adjustment range of the two adjacent sub-grids 20 can be greater than 0.96 mm and less than 1.04 mm.

[0071] Optionally, when A is equal to 50, the mesh size is 50 μm. Assuming that the initial spacing between two adjacent sub-grids 20 with the same polarity is 1 mm, when the two adjacent sub-grids 20 cover the yarn corresponding to the mesh knot 30 or contact at least a partial area corresponding to the mesh knot 30, the spacing adjustment range of the two adjacent sub-grids 20 can be greater than 0.95 mm and less than 1.05 mm.

[0072] In some embodiments, the initial distance between two adjacent sub-grids 20 of the same polarity is 0.9 mm to 1.1 mm.

[0073] Optionally, when A is equal to 40, the mesh size is 40 μm. Assuming that the initial spacing between two adjacent sub-grids 20 with the same polarity is 0.9 mm, when the two adjacent sub-grids 20 cover the yarn corresponding to the mesh knot 30 or contact at least a partial area corresponding to the mesh knot 30, the spacing adjustment range of the two adjacent sub-grids 20 can be greater than 0.86 mm and less than 0.94 mm.

[0074] Optionally, when A is equal to 40, the mesh size is 40 μm. Assuming that the initial spacing between two adjacent sub-grids 20 with the same polarity is 1 mm, when the two adjacent sub-grids 20 cover the yarn corresponding to the mesh knot 30 or contact at least a partial area corresponding to the mesh knot 30, the spacing adjustment range of the two adjacent sub-grids 20 can be greater than 0.96 mm and less than 1.04 mm.

[0075] Optionally, when A is equal to 40, the mesh size is 40 μm. Assuming that the initial spacing between two adjacent sub-grids 20 with the same polarity is 1.1 mm, when the two adjacent sub-grids 20 cover the yarn corresponding to the mesh knot 30 or contact at least a partial area corresponding to the mesh knot 30, the spacing adjustment range of the two adjacent sub-grids 20 can be greater than 1.06 mm and less than 1.14 mm.

[0076] In some embodiments, the line width of the first sub-gate 201 is less than 33 μm.

[0077] In actual implementation, the first auxiliary grid 201 is a P-region auxiliary grid, and the line width of a conventional P-region auxiliary grid is about 38 μm. Since the printed pattern corresponding to the first auxiliary grid 201 can avoid the mesh knot, the printed second auxiliary grid 202 is not prone to gate breakage, so the line width of the first auxiliary grid 201 can be reduced. The first auxiliary grid 201 in the embodiment of the present invention can be 5 μm to 6 μm less than the width of the conventional P-region auxiliary grid, that is, the line width of the first auxiliary grid 201 can be less than 33 μm. Thinning the first auxiliary grid 201 can increase the light receiving area and improve the conversion efficiency of the solar cell.

[0078] It is understandable that, in the case of printing a wider secondary grid, it is not necessary to consider whether the printed pattern corresponding to the wider secondary grid overlaps with the mesh knot, and the slurry can be directly printed through the mesh knot without breaking the grid.

[0079] In some embodiments, the line width of the second sub-gate 202 is less than 30 μm.

[0080] In actual implementation, the second sub-grid 202 is an N-region sub-grid, and the line width of a conventional N-region sub-grid is about 35 μm. Since the printed pattern corresponding to the second sub-grid 202 can avoid the mesh knot, the printed second sub-grid 202 is not prone to gate breakage, so the line width of the second sub-grid 202 can be reduced. The second sub-grid 202 in the embodiment of the present invention can be 5 μm to 6 μm less than the width of the conventional N-region sub-grid, that is, the line width of the second sub-grid 202 can be less than 30 μm. Thinning the second sub-grid 202 can increase the light receiving area and improve the conversion efficiency of the solar cell.

[0081] Figure 5 Schematic diagram of the structure of the photovoltaic module provided by the embodiment of the present invention. Figure 5 As shown, the present invention further provides a photovoltaic assembly 100, comprising the solar cell 101 in any of the above embodiments.

[0082] The solar cell 101 has been described in detail in the above embodiment, and will not be described again here.

[0083] In the photovoltaic module provided by the embodiment of the present invention, in order to avoid the mesh knot on the printed screen, among the several sub-grids arranged on the silicon substrate, there is at least one group of sub-grids with unequal spacing between two adjacent sub-grids, and there is also at least one sub-grid with the same polarity and two adjacent sub-grids with unequal spacing, so that by adjusting the spacing of the sub-grids, the possibility of the sub-grids overlapping with the mesh knots can be reduced, thereby reducing the problem of broken grids and improving the product yield of solar cells.

[0084] Figure 6 Schematic diagram of the structure of the photovoltaic system provided by the embodiment of the present invention. Figure 6 As shown, the present invention further provides a photovoltaic system 200, comprising the photovoltaic assembly 100 in any of the above embodiments.

[0085] The photovoltaic assembly 100 has been described in the above embodiments and will not be described again herein.

[0086] In the photovoltaic system provided by the embodiment of the present invention, in order to avoid the mesh knot on the printed screen, among the several sub-grids arranged on the silicon substrate, there is at least one group of sub-grids in which the spacing between two adjacent sub-grids is unequal, and there is also at least one sub-grid in which the spacing between two adjacent sub-grids with the same polarity is unequal, so that by adjusting the spacing of the sub-grids, the possibility of the sub-grids overlapping with the mesh knots can be reduced, thereby reducing the problem of broken grids and improving the product yield of solar cells.

[0087] Figure 7 Schematic diagram of the structure of the printing screen provided by the embodiment of the present invention. Figure 7 As shown, an embodiment of the present invention further provides a printing screen 300, comprising: a screen frame 3000, a mesh 3001 and a plurality of printed graphics 3002 corresponding to sub-grids, the mesh 3001 being fixed on the screen frame 3000, and the printed graphics 3002 being located on the mesh 3001; the mesh 3001 being interwoven with warp threads and weft threads, and the warp threads and the weft threads intersecting to form a plurality of mesh knots 3003; the printed graphics 3002 does not pass through the plurality of mesh knots 3003.

[0088] The material of mesh 3001 can be nylon mesh, polyester mesh, stainless steel mesh, etc., which are not specifically limited here. The wefts in mesh 3001 extend along the first direction, and the warps in mesh 3001 extend along the second direction. All the warps in mesh 3001 are parallel to each other and parallel to the two edges of mesh frame 3000 in the first direction, and all the wefts in mesh 3001 are parallel to each other and parallel to the two edges of mesh frame 3000 in the second direction. It can be understood that Figure 7 The figure only illustrates the mesh 3001 in a partial area of ​​the printing screen, which does not represent a limitation on the shape of the mesh 3001.

[0089] In actual implementation, the mesh 3001 is formed by interweaving warp and weft to form a grid, and each grid corresponds to a mesh hole.

[0090] like Figure 7 As shown, the opening position corresponding to the printed pattern 3002 is located between two adjacent weft lines, that is, between two adjacent knots in the first direction, so that the area where the printed pattern 3002 is located is an area that is not in contact with the knots.

[0091] The printing screen provided in the embodiment of the present invention can avoid mesh knots in the printed pattern of the secondary grid, reduce the occurrence of broken grids, improve the printing effect of the secondary grid, and help further refine the line width of the secondary grid, thereby improving the photoelectric conversion efficiency of the solar cell.

[0092] It is understandable that those skilled in the art can, under the guidance of the above embodiments, combine various implementation methods in the above embodiments to obtain technical solutions of multiple implementation methods.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A solar cell, characterized in that: include: A silicon substrate and a plurality of auxiliary gates, wherein the plurality of auxiliary gates include two types of auxiliary gates with different polarities; The plurality of sub-gates are arranged on the silicon substrate and extend along a first direction, the two sub-gates with different polarities are alternately arranged along a second direction, and the first direction intersects with the second direction; Among the plurality of sub-grids, the first sub-grid has unequal spacings from the second sub-grid and the third sub-grid; the second sub-grid and the third sub-grid are both adjacent to the first sub-grid and have different properties from the first sub-grid; In the auxiliary grid having the same characteristics as the first auxiliary grid, the first auxiliary grid has unequal intervals with the fourth auxiliary grid and the fifth auxiliary grid, and the fourth auxiliary grid and the fifth auxiliary grid are both adjacent to the first auxiliary grid.

2. The solar cell according to claim 1, characterized in that The interval between two adjacent sub-grids of the same polarity is adjusted based on the mesh size of the printing screen corresponding to the sub-grids of the same polarity.

3. The solar cell according to claim 2, characterized in that: The mesh size is A μm, and the initial spacing between two adjacent sub-grids of the same polarity is B mm; In the case where two adjacent sub-grids of the sub-grids with the same polarity include a target sub-grid, the spacing adjustment range of the two adjacent sub-grids of the sub-grids with the same polarity is greater than (BA) mm and less than (B+A) mm; the target sub-grid is a sub-grid whose printed patterns corresponding to the plurality of sub-grids contact the mesh knot of the printing screen.

4. The solar cell according to claim 3, characterized in that: The mesh size is 40 μm to 50 μm.

5. The solar cell according to claim 3, characterized in that: The initial spacing between two adjacent sub-grids of the same polarity is 0.9 mm to 1.1 mm.

6. The solar cell according to claim 1, characterized in that The line width of the first secondary gate is less than 33 μm.

7. The solar cell according to claim 1, characterized in that The line width of the second sub-gate is less than 30 μm.

8. A photovoltaic module, characterized in that: include: The solar cell according to any one of claims 1 to 7.

9. A photovoltaic system, characterized in that: include: The photovoltaic system of claim 8.

10. A printing screen, characterized in that: include: A screen frame, a mesh cloth and a plurality of printed graphics corresponding to the auxiliary grids, wherein the mesh cloth is fixed on the screen frame and the printed graphics are located on the mesh cloth; The mesh cloth is formed by interweaving warp threads and weft threads, and the warp threads and weft threads intersect to form a plurality of mesh knots; the printed pattern does not pass through the plurality of mesh knots.

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