Solar cell and photovoltaic module

Abstract

The present application relates to the technical field of photovoltaic modules, and discloses a solar cell and a photovoltaic module. The solar cell comprises a substrate and a transmission electrode; the transmission electrode is provided on a surface of the substrate and is electrically connected to the substrate; a plurality of protrusions are sequentially provided on the side of the transmission electrode distant from the substrate; and the plurality of protrusions are arranged in an array, and adjacent protrusions are at least partially connected. In the present application, a region formed between adjacent protrusions on the transmission electrode is a recess, thereby reducing the consumption of the transmission electrode material, and reducing costs of the transmission electrode. In addition, adjacent protrusions are at least partially connected, thereby ensuring the current transmission efficiency of the transmission electrode, reducing power loss of the transmission electrode, and ensuring the photoelectric conversion efficiency of the solar cell.

Description

Solar cells and photovoltaic modules

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411814264.0, filed on December 10, 2024, entitled “Solar Cells and Photovoltaic Modules”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of photovoltaic module technology, specifically to a solar cell and a photovoltaic module. Background Technology

[0004] With the rapid development of the photovoltaic industry, competition is becoming increasingly fierce, and the cost of photovoltaic modules has attracted widespread attention. Solar cells, as the core component of photovoltaic modules, convert solar energy into electrical energy. A solar cell consists of a substrate and transmission electrodes disposed on the surface of the substrate. These transmission electrodes collect the current generated by the substrate and transmit it to an external circuit.

[0005] In related technologies, base metal pastes are used to prepare transmission electrodes in order to reduce the cost of solar cells. For example, the base metal can be copper, aluminum, etc.

[0006] However, in the photovoltaic industry, how to further reduce the cost of transmission electrodes while ensuring current transmission efficiency remains a pressing issue. Summary of the Invention

[0007] This application discloses a solar cell and a photovoltaic module to solve, or at least partially solve, the problems existing in the prior art, such as the high cost of transmission electrodes and the inability to guarantee current transmission efficiency.

[0008] To solve the above-mentioned technical problems, this application is implemented as follows:

[0009] In a first aspect, this application discloses a solar cell, which includes a substrate and a transmission electrode. The transmission electrode is disposed on the surface of the substrate and electrically connected to the substrate. A plurality of protrusions are sequentially disposed on the side of the transmission electrode away from the substrate. The plurality of protrusions are arranged in an array, and adjacent protrusions are at least partially connected.

[0010] Optionally, a group of protrusions arranged sequentially along the second direction forms a set of protrusions, and the multiple sets of protrusions are arranged sequentially along the first direction; wherein, the extension direction of the transmission electrode is a third direction, the second direction is parallel to or intersects the third direction, and the first direction intersects the second direction and the third direction.

[0011] Optionally, the second direction and the third direction have a first included angle, which is greater than or equal to 0 degrees and less than or equal to 60 degrees.

[0012] Optionally, the first included angle is greater than or equal to 0 degrees and less than or equal to 45 degrees.

[0013] Optionally, there is a second angle between the first direction and the second direction, and the second angle is less than or equal to 90 degrees.

[0014] Optionally, the plurality of protrusions include a plurality of spaced-apart third protrusions and a plurality of spaced-apart fourth protrusions; any one of the third protrusions is at least partially connected to the plurality of fourth protrusions, and the plurality of fourth protrusions connected to the third protrusions are arranged in a circular array along the circumference of the third protrusions; any one of the fourth protrusions is at least partially connected to the plurality of third protrusions, and the plurality of third protrusions connected to the fourth protrusions are arranged in a circular array along the circumference of the fourth protrusions.

[0015] Optionally, adjacent protrusions enclose a first region, and the recess of the transmission electrode corresponds to the first region.

[0016] Optionally, along the thickness direction of the solar cell, the height of the protrusion is greater than or equal to 5 μm and less than or equal to 30 μm; the height of the protrusion is the distance between the top of the protrusion and the bottom of the recess.

[0017] Optionally, along the thickness direction of the solar cell, the height of the protrusion is greater than or equal to 5 μm and less than or equal to 15 μm.

[0018] Optionally, the projection of the protrusion onto the plane of the base is at least one of a cross-shaped structure, a hexagonal structure, or a triangular structure.

[0019] Optionally, the line connecting the center points of each of the protrusions in each group is on a straight line.

[0020] Optionally, the number of the recesses is multiple, and the multiple recesses are arranged in an array.

[0021] Optionally, the recessed portion includes a first recessed portion and a second recessed portion, the area of ​​the second recessed portion being a multiple of the area of ​​the first recessed portion; and / or, the protruding portion includes a first protruding portion and a second protruding portion, the area of ​​the second protruding portion being a multiple of the area of ​​the first protruding portion.

[0022] Optionally, the distance between the center points of two adjacent recesses is greater than or equal to 20 μm and less than or equal to 100 μm.

[0023] Optionally, along the thickness direction of the solar cell, the distance between the bottom of the recess and the top of the protrusion is a first depth, and the ratio of the first depth to the distance between the center points of two adjacent recesses is greater than or equal to 0.1 and less than or equal to 1.

[0024] Optionally, along the thickness direction of the solar cell, the thickness of the transmission electrode at the position corresponding to the protrusion is greater than or equal to 9 μm and less than or equal to 50 μm; and / or, along the thickness direction of the solar cell, the thickness of the transmission electrode at the position corresponding to the recess is greater than or equal to 1 μm and less than or equal to 20 μm.

[0025] Optionally, the projection of the recessed portion onto the plane of the substrate is at least one of a circular structure, an elliptical structure, a near-elliptical structure, a square structure, a near-square structure, a triangular structure, and a near-triangular structure.

[0026] Optionally, there are multiple transmission electrodes, each extending along a third direction and spaced apart along a fourth direction; the fourth direction intersects the third direction; wherein at least one transmission electrode includes a collector grid line and an electrical connection disk, a plurality of electrical connection disks are disposed on the collector grid line and spaced apart along the third direction, and a plurality of protrusions arranged in an array are disposed on the surface of the electrical connection disk away from the substrate; preferably, there are multiple collector grid lines, and a plurality of electrical connection disks located on different collector grid lines are spaced apart along the fourth direction to form an electrical connection disk group.

[0027] Optionally, the area on the current collector grid line where no electrical connection pad is provided has multiple non-arrayed protrusions on the surface away from the substrate.

[0028] Optionally, the solar cell is a back-contact solar cell.

[0029] Optionally, the surface of the electrical connection pad away from the substrate is coated with a conductive layer.

[0030] Optionally, the solar cell further includes a passivation layer and a contact electrode, the passivation layer being stacked between the substrate and the transmission electrode; the contact electrode passing through the passivation layer, with one end of the contact electrode electrically connected to the substrate and the other end of the contact electrode electrically connected to the transmission electrode.

[0031] Optionally, the transmission electrode has a first projection on the plane where the substrate is located, and the contact electrode has a second projection on the plane where the substrate is located, the second projection falling within the first projection.

[0032] Optionally, along the fourth direction, the width of the transmission electrode is greater than or equal to 60 μm; and / or, along the fourth direction, the width of the contact electrode is greater than or equal to 10 μm and less than or equal to 40 μm.

[0033] Optionally, the substrate has a first surface and a second surface disposed opposite to each other, the passivation layer is stacked on the first surface of the substrate, and / or the passivation layer is stacked on the second surface of the substrate.

[0034] Optionally, along the second direction, the distance between the center points of two adjacent protrusions is W1; along the fourth direction, the width of the contact electrode is W2, satisfying -2 < lg(W2 / W1) < 2; wherein, the second direction intersects the third direction, and the fourth direction is perpendicular to the third direction.

[0035] Optionally, -1 < lg(W2 / W1) < 1 is satisfied.

[0036] Optionally, W2 ≥ 30 μm must be satisfied.

[0037] Optionally, W1 < 2W2 must be satisfied.

[0038] Optionally, the distance between the center points of two adjacent recesses is W3, and the width of the contact electrode along the fourth direction is W2, satisfying W2-W3>10μm.

[0039] Optionally, the substrate includes a first surface and a second surface disposed opposite to each other, the second surface having a first electrode region and a second electrode region disposed adjacent to each other, the first electrode region and the second electrode region having opposite polarities; the transmission electrode includes a first transmission electrode and a second transmission electrode, the first transmission electrode being disposed in the first electrode region and electrically connected to the first electrode region, the second transmission electrode being disposed in the second electrode region and electrically connected to the second electrode region; wherein, along the thickness direction of the solar cell, the height of the protrusion in the first transmission electrode is the same as or different from the height of the protrusion in the second transmission electrode.

[0040] Optionally, the distance between the center points of two adjacent recesses in the first transmission electrode is different from the distance between the center points of two adjacent recesses in the second transmission electrode.

[0041] Secondly, this application discloses a photovoltaic module comprising the solar cells described in the first aspect.

[0042] This application discloses a solar cell and a photovoltaic module. The solar cell includes a substrate and a transmission electrode. The transmission electrode is disposed on the surface of the substrate and electrically connected to the substrate. A plurality of protrusions are sequentially disposed on the side of the transmission electrode away from the substrate. The plurality of protrusions are arranged in an array, and adjacent protrusions are at least partially connected.

[0043] In this application, multiple protrusions are sequentially arranged on the side of the transfer electrode away from the substrate, and these protrusions are arranged in an array. That is, the area formed between adjacent protrusions on the transfer electrode is a recess. This arrangement reduces the amount of transfer electrode material used, thereby lowering the cost of the transfer electrode.

[0044] Furthermore, in this application, multiple protrusions are arranged in an array, and adjacent protrusions are at least partially connected, which can also ensure the current transmission efficiency of the transmission electrode, reduce the power loss of the transmission electrode, and ensure the photoelectric conversion efficiency of the solar cell. Attached Figure Description

[0045] Figure 1 shows a schematic diagram of the structure of the solar cell described in an embodiment of this application;

[0046] Figure 2 shows a second schematic diagram of the structure of the solar cell described in this application embodiment;

[0047] Figure 3 shows a schematic diagram of the structure of the solar cell described in the embodiment of this application;

[0048] Figure 4 shows a schematic diagram of the structure of the solar cell described in the embodiment of this application;

[0049] Figure 5 shows a schematic diagram of the structure of the solar cell described in the embodiment of this application;

[0050] Figure 6 shows a schematic diagram of the structure of the solar cell described in the embodiment of this application;

[0051] Figure 7 shows a schematic diagram of the structure of the solar cell described in the embodiment of this application;

[0052] Figure 8 shows a schematic diagram of the structure of the solar cell described in the embodiment of this application;

[0053] Figure 9 shows a side view of the solar cell described in an embodiment of this application;

[0054] Figure 10 shows a schematic diagram of the contact electrode in an embodiment of this application;

[0055] Figure 11 shows a schematic diagram of the structure of the transmission electrode in an embodiment of this application;

[0056] Figure 12 shows a front view of the collector grid line described in an embodiment of this application.

[0057] Reference numerals: 10: Substrate; 20: Passivation layer; 30: Contact electrode; 40: Transmission electrode; 41: Protrusion; 411: First protrusion; 412: Second protrusion; 413: Third protrusion; 414: Fourth protrusion; 42: Connecting portion; 43: Recess; 431: First recess; 432: Second recess; 401: Collector grid line; 402: Electrical connection pad; 44: Raised area; 45: Pits; A: First direction; B: Second direction; C: Third direction; D: Fourth direction. Detailed Implementation

[0058] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of this application.

[0059] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0060] Referring to Figure 1, a schematic diagram of the structure of the solar cell in this embodiment of the present application is shown; referring to Figure 2, a schematic diagram of the structure of the solar cell in this embodiment of the present application is shown; referring to Figure 3, a schematic diagram of the structure of the solar cell in this embodiment of the present application is shown; referring to Figure 4, a schematic diagram of the structure of the solar cell in this embodiment of the present application is shown; referring to Figure 5, a schematic diagram of the structure of the solar cell in this embodiment of the present application is shown; referring to Figure 6, a schematic diagram of the structure of the solar cell in this embodiment of the present application is shown; referring to Figure 7, a schematic diagram of the structure of the solar cell in this embodiment of the present application is shown; referring to Figure 8, a schematic diagram of the structure of the solar cell in this embodiment of the present application is shown; referring to Figure 9, a side view of the solar cell in this embodiment of the present application is shown; referring to Figure 10, a schematic diagram of the structure of the contact electrode in this embodiment of the present application is shown; Figure 11 shows a schematic diagram of the structure of the transmission electrode in this embodiment of the present application; Figure 12 shows a front view of the current collector grid in this embodiment of the present application.

[0061] As shown in Figures 1 to 10, this application discloses a solar cell, which includes a substrate 10 and a transmission electrode 40. The transmission electrode 40 is disposed on the surface of the substrate 10 and electrically connected to the substrate 10. A plurality of protrusions 41 are sequentially disposed on the side of the transmission electrode 40 away from the substrate 10. The plurality of protrusions 41 are arranged in an array, and adjacent protrusions 41 are at least partially connected.

[0062] This application discloses a solar cell comprising a substrate 10 and a transmission electrode 40. The substrate 10 absorbs solar energy and converts it into electrical energy. The substrate 10 can be P-type, N-type, or a silicon wafer of a near-intrinsic conductivity type. The crystal type of the substrate 10 can be monocrystalline or polycrystalline. In this application embodiment, no excessive restrictions are placed on the specific type of the substrate 10. In practical applications, those skilled in the art can choose according to their needs.

[0063] The substrate 10 in this embodiment has a first surface and a second surface disposed opposite to each other. The first surface can be a sun-receiving surface facing the sunlight, also known as the front surface. The first surface can also be a shadow-receiving surface facing away from the sunlight, also known as the back surface. When the first surface is the front surface, the second surface is the back surface. When the first surface is the back surface, the second surface is the front surface.

[0064] The following will use the first surface of the substrate 10 as the front side and the second surface as the back side as an example to describe the relevant embodiments of this application.

[0065] As shown in Figures 1 to 10, in this embodiment, the transmission electrode 40 is disposed on the surface of the substrate 10 and electrically connected to the substrate 10 to collect the current generated by the substrate 10. It should be noted that the transmission electrode 40 may be disposed only on the second surface of the substrate 10, meaning the solar cell is a back-contact solar cell. Alternatively, the transmission electrode 40 may be disposed on both the first and second surfaces of the substrate 10, meaning the solar cell is a bifacial cell.

[0066] In this embodiment, a plurality of protrusions 41 are sequentially arranged on the side of the transmission electrode 40 away from the substrate 10. These protrusions 41 are arranged in an array, and adjacent protrusions 41 are at least partially connected. That is, the area formed between adjacent protrusions 41 on the transmission electrode 40 is a recess 43, and the protrusions 41 or recesses 43 are arranged in an array. This arrangement reduces the amount of material used in the transmission electrode 40, thus reducing its cost.

[0067] It is understood that the array arrangement in this application refers to a two-dimensional arrangement, with at least two rows and two columns.

[0068] Furthermore, in this embodiment, the multiple protrusions 41 are arranged in an array, and adjacent protrusions 41 are at least partially connected, which can also ensure the current transmission efficiency of the transmission electrode, reduce the power loss of the transmission electrode 40, and ensure the photoelectric conversion efficiency of the solar cell.

[0069] It should be noted that the transmission electrode 40 in this embodiment is made of a base metal. This base metal can be copper, aluminum, or other metals that are cheaper than copper or aluminum.

[0070] As shown in Figures 1 to 4, the multiple protrusions 41 in this embodiment have the same structure and are arranged in an array on the side of the transmission electrode 40 away from the substrate 10. This not only reduces the amount of material used in the transmission electrode 40 and lowers its manufacturing cost, thereby reducing the cost of the solar cell and enhancing its market competitiveness, but also ensures the current transmission efficiency of the transmission electrode 40 and the photoelectric conversion efficiency of the solar cell.

[0071] It should be noted that in the embodiments of this application, the structures of the multiple protrusions 41 can be completely identical. For example, the multiple protrusions 41 can all be cross-shaped structures. The structures of the multiple protrusions 41 can also be partially identical. For example, some of the multiple protrusions 41 can be cross-shaped structures, while others can have other structures.

[0072] Optionally, as shown in Figures 1 to 7, in the embodiments of this application, a plurality of protrusions 41 are arranged sequentially along the second direction B to form a group of protrusions 41, and multiple groups of protrusions 41 are arranged sequentially along the first direction A; wherein, the extension direction of the transmission electrode 40 is the third direction C, the second direction B is parallel to or intersects with the third direction C, and the first direction A intersects with the second direction B and the third direction C.

[0073] As shown in Figures 1 to 7, multiple sets of protrusions 41 are arranged sequentially along a first direction A, and multiple protrusions 41 in each set are arranged sequentially along a second direction B. The second direction B may be the same as the extension direction of the transmission electrode 40, i.e., the same as the third direction C. The second direction B may also form an angle with the extension direction of the transmission electrode 40, which is typically an acute angle. The second direction B intersects the first direction A; exemplarily, the second direction B is perpendicular to the first direction A.

[0074] In this embodiment, multiple sets of protrusions 41 are arranged sequentially along a first direction A, and multiple protrusions 41 in each set are arranged sequentially along a second direction B, so that the multiple protrusions 41 are arranged in an array on the side of the transmission electrode 40 away from the substrate 10. The arrayed arrangement of multiple protrusions 41 not only reduces the amount of material used in the transmission electrode 40 and lowers the manufacturing cost of the transmission electrode 40, thereby reducing the cost of the solar cell and enhancing its market competitiveness, but also ensures the current transmission efficiency of the transmission electrode 40 and the photoelectric conversion efficiency of the solar cell.

[0075] Optionally, as shown in FIG3, the second direction B and the third direction C in this embodiment of the application have a first included angle, which is greater than or equal to 0 degrees and less than or equal to 60 degrees.

[0076] As shown in Figure 3, in this embodiment of the application, the first angle between the second direction B and the third direction C is set to be greater than or equal to 0 degrees and less than or equal to 60 degrees, so that the extension direction of each set of protrusions 41 has an angle of less than or equal to 60 degrees with the extension direction of the transmission electrode 40, thereby further enhancing the current transmission capability of the transmission electrode 40 and improving the photoelectric conversion efficiency of the solar cell.

[0077] For example, the first included angle between the second direction B and the third direction C can be set to 0°, 10°, 20°, 30°, 40°, 50°, 60°, etc.

[0078] In a preferred embodiment of this application, the first included angle can be set to be greater than or equal to 0 degrees and less than or equal to 45 degrees. This ensures that the extension direction of each set of protrusions 41 has an angle of less than or equal to 45 degrees with the extension direction of the transmission electrode 40, thereby further increasing the current transmission capability of the transmission electrode 40 and improving the photoelectric conversion efficiency of the solar cell.

[0079] For example, the first included angle between the second direction B and the third direction C can be set to 0°, 15°, 25°, 35°, 45°, etc.

[0080] As a preferred embodiment, as shown in FIG3, the first direction A and the second direction B in this embodiment of the application have a second included angle, which is less than or equal to 90 degrees.

[0081] In this embodiment, the second included angle between the first direction A and the second direction B is set to be less than or equal to 90 degrees. Taking a 90-degree second included angle between the first direction A and the second direction B as an example, this means that the first direction A is perpendicular to the second direction B. This arrangement allows the multiple sets of protrusions 41 to be arranged in a direction perpendicular to the extension direction of each set of protrusions 41, thereby providing more protrusions 41 on the side of the transmission electrode 40 away from the substrate 10. This further improves the current transmission efficiency of the transmission electrode 40, reduces the amount of material used in the transmission electrode 40, and enhances the market competitiveness of the solar cell.

[0082] Of course, the above arrangement also makes the connection between adjacent protrusions 41 more reliable, thereby helping to improve the current transmission efficiency of the transmission electrode 40 and the photoelectric conversion efficiency of the solar cell. It avoids the situation where adjacent protrusions 41 are not connected, which would affect the transmission efficiency of the solar cell.

[0083] For example, the second included angle between the first direction A and the second direction B can be 90 degrees, 85 degrees, 80 degrees, 75 degrees, 70 degrees, 65 degrees, etc.

[0084] Optionally, the plurality of protrusions 41 include a plurality of spaced third protrusions 413 and a plurality of spaced fourth protrusions 414.

[0085] Any third protrusion 413 is at least partially connected to a plurality of fourth protrusions 414, and the plurality of fourth protrusions 414 connected to the third protrusion 413 are arranged in a circular array along the circumference of the third protrusion 413.

[0086] Any fourth protrusion 414 is at least partially connected to a plurality of third protrusions 413, and the plurality of third protrusions 413 connected to the fourth protrusion 414 are arranged in a circular array along the circumference of the fourth protrusion 414.

[0087] To facilitate understanding of this solution, the embodiment shown in Figure 8 is used as an example. The third protrusion 413 has a triangular star structure, and the fourth protrusion 414 has a hexagonal star structure. For any triangular star structure of the third protrusion 413, three hexagonal star structure of the fourth protrusion 414 surround its periphery, and these three fourth protrusions 414 are connected to the third protrusion 413.

[0088] For any hexagonal star structure, the fourth protrusion 414 is surrounded by six triangular star structures, and these six third protrusions 413 are connected to the fourth protrusion 414.

[0089] Optionally, as shown in Figures 1 to 8, in the embodiments of this application, adjacent protrusions 41 enclose a first region, and the first region corresponds to the recessed portion 43 of the transmission electrode 40.

[0090] In this embodiment of the application, as shown in Figures 1 to 8, adjacent protrusions 41 enclose a first region, and corresponding to the first region is a recess 43 of the transmission electrode 40. The recess 43 can reduce the amount of material used in the transmission electrode 40, reduce the cost of the transmission electrode 40, thereby helping to reduce the cost of solar cells and enhance the market competitiveness of solar cells.

[0091] Taking the protrusion 41 as a cross-shaped structure as an example, two adjacent protrusions 41 along the first direction A and two protrusions 41 opposite to the two protrusions 41 along the second direction B can enclose and form a first region. The transmission electrode 40 corresponding to this first region is a recess 43. It can be understood that the transmission electrode 40 has multiple first regions, that is, the transmission electrode 40 has multiple recesses 43.

[0092] Optionally, along the thickness direction of the solar cell, the height of the protrusion 41 is greater than or equal to 5 μm and less than or equal to 30 μm, and the height of the protrusion 41 is the distance between the top of the protrusion 41 and the bottom of the recess 43.

[0093] In this embodiment, the height H1 of the protrusion 41 is set to be greater than or equal to 5 μm and less than or equal to 30 μm along the thickness direction of the solar cell. This setting not only reduces the amount of material used in the transmission electrode 40 and lowers the manufacturing cost of the transmission electrode 40, thereby helping to reduce the cost of the solar cell and enhance its market competitiveness, but also enables the transmission electrode 40 to have higher transmission efficiency, ensuring the photoelectric conversion efficiency of the solar cell.

[0094] For example, along the thickness direction of the solar cell, the height H1 of the protrusion 41 can be set to 5μm, 8μm, 10μm, 15μm, 20μm, 25μm, 30μm, etc.

[0095] In a preferred embodiment, the height H1 of the protrusion 41 can be set to be greater than or equal to 5 μm and less than or equal to 15 μm along the thickness direction of the solar cell. This setting can further reduce the amount of material used in the transmission electrode 40, thereby reducing the manufacturing cost of the transmission electrode 40. Simultaneously, it enables the transmission electrode 40 to have higher current transmission efficiency, thus ensuring the photoelectric conversion efficiency of the solar cell.

[0096] For example, the height H1 of the protrusion 41 can be set to 5μm, 7μm, 9μm, 10μm, 12μm, 14μm, 15μm, etc. along the thickness direction of the solar cell.

[0097] In this embodiment, the height H1 of the protrusion 41 is set to be greater than or equal to 5 μm and less than or equal to 15 μm along the thickness direction of the solar cell. This further reduces the amount of material used in the transmission electrode 40, reduces the manufacturing cost of the transmission electrode 40, and ensures that the transmission electrode 40 has a high current transmission capability to guarantee the photoelectric conversion efficiency of the solar cell.

[0098] Optionally, as shown in Figures 1 to 8, the projection of the protrusion 41 on the plane of the base 10 in the embodiments of this application is at least one of a cross-shaped structure, a hexagonal structure, and a triangular structure.

[0099] As shown in Figures 1 to 8, the protrusion 41 in this embodiment of the application has a projection onto the plane of the base 10. This projection includes, but is not limited to, one or more of a cross-shaped structure, a hexagonal structure, and a triangular structure. That is, the projection of the protrusion 41 onto the plane of the base 10 may include only a cross-shaped structure, or only a hexagonal structure, or only a triangular structure. Alternatively, the projection of the protrusion 41 onto the plane of the base 10 may include both a cross-shaped and a hexagonal structure, or both a cross-shaped and a triangular structure, or both a hexagonal and a triangular structure.

[0100] Of course, the above are just individual examples of embodiments of this application and are not intended to limit the application. In practical applications, those skilled in the art can set the specific structure of the protrusion 41 as needed.

[0101] In this embodiment, the projection of the protrusion 41 onto the plane of the substrate 10 is set to at least one of a cross-shaped structure, a hexagonal structure, and a triangular structure. These structures have multiple connecting edges around the center point to facilitate the connection of adjacent protrusions 41, thereby reducing the power loss of the transmission electrode 40, improving the current transmission efficiency of the transmission electrode 40, and ensuring the photoelectric conversion efficiency of the solar cell.

[0102] Furthermore, the above-mentioned configuration can reduce the amount of material used in the transmission electrode 40, reduce the manufacturing cost of the transmission electrode 40, thereby reducing the cost of the solar cell and enhancing its market competitiveness.

[0103] As shown in Figures 1 to 8, when the projection of the protrusion 41 onto the plane of the substrate 10 forms a cross shape, multiple connecting portions 42 can be sequentially arranged on the side of the transmission electrode 40 away from the substrate 10. Each connecting portion 42 connects two adjacent protrusions 41, thereby increasing the current transmission path of the transmission electrode 40. When poor contact occurs in some areas of the transmission electrode 40, or when the resistance of some areas of the transmission electrode 40 is high, the current can be transmitted along the path with lower resistance, thereby reducing the current transmission distance and improving the current transmission efficiency of the transmission electrode 40.

[0104] Taking the protrusion 41 as a cross-shaped structure as an example, the connecting part 42 can be a ridge strip, which connects adjacent protrusions 41. The extension line of the ridge strip connecting the two opposite vertices of the protrusion 41 points to the center of the protrusion 41.

[0105] Optionally, as shown in Figures 1 to 7, in the embodiments of this application, the connecting lines of the center points of each protrusion 41 in each group of protrusions 41 are on a straight line.

[0106] As shown in Figures 1 to 7, in this embodiment of the application, the connecting line of the center point of each protrusion 41 in each group of protrusions 41 is set on a straight line to shorten the current transmission path of the transmission electrode 40, improve the current transmission efficiency, and ensure the photoelectric conversion efficiency of the solar cell.

[0107] Optionally, as shown in Figures 1 to 8, the number of recesses 43 in the embodiments of this application is multiple, and the multiple recesses 43 are arranged in an array.

[0108] As shown in Figures 1 to 4, 7, and 8, the multiple recesses 43 in the embodiments of this application have the same or similar structures, and are arranged in an array. The multiple recesses 43 are arranged in an orderly manner in the second direction B to form a first recess group. That is, a row of recesses 43 arranged sequentially in the second direction B constitutes a first recess group. Multiple first recess groups are included, and these groups are arranged sequentially in the first direction A. This reduces the amount of material used in the transmission electrode 40, lowers the manufacturing cost of the transmission electrode 40, thereby reducing the cost of the solar cell and enhancing its market competitiveness.

[0109] It should be noted that in the embodiments of this application, the structures of the multiple recesses 43 can be completely identical. For example, the projections of the multiple recesses 43 onto the plane where the base 10 is located are all circular. The structures of the multiple recesses 43 can also be partially identical. For example, a portion of the multiple recesses 43 may have a circular projection onto the plane where the base 10 is located, while another portion may be rectangular.

[0110] Optionally, as shown in FIG5, the recessed portion 43 in the embodiment of this application includes a first recessed portion 431 and a second recessed portion 432, wherein the area of ​​the second recessed portion 432 is multiple times the area of ​​the first recessed portion 431.

[0111] As shown in Figure 5, the recessed portion 43 in this embodiment includes a first recessed portion 431 and a second recessed portion 432, and the second recessed portion 432 includes a plurality of first recessed portions 431. That is, the plurality of first recessed portions 431 are directly connected to form the second recessed portion 432, and no protrusions 41 are provided in the middle. Therefore, the area of ​​the second recessed portion 432 is many times the area of ​​the first recessed portion 431.

[0112] For example, the second recess 432 is formed by connecting four first recesses 431, and there is no protrusion 41 in the middle. Therefore, the area of ​​the second recess 432 is greater than four times the area of ​​the first recess 431.

[0113] In this embodiment, by setting the area of ​​the second recess 432 to be multiple times the area of ​​the first recess 431, the amount of material used in the transmission electrode 40 is further reduced, the manufacturing cost of the transmission electrode 40 is reduced, thereby reducing the cost of the solar cell and enhancing its market competitiveness.

[0114] Optionally, as shown in FIG6, the protrusion 41 in the embodiment of this application includes a first protrusion 411 and a second protrusion 412, wherein the area of ​​the second protrusion 412 is multiple times the area of ​​the first protrusion 411.

[0115] As shown in Figure 6, the protrusion 41 in this embodiment includes a first protrusion 411 and a second protrusion 412, and the second protrusion 412 includes a plurality of first protrusions 411. That is, the plurality of first protrusions 411 are directly connected to form the second protrusion 412, without any recess 43 in between. Therefore, the area of ​​the second protrusion 412 is many times the area of ​​the first protrusion 411.

[0116] For example, the second protrusion 412 is formed by connecting three first protrusions 411, and there is no recess 43 in the middle. Therefore, the area of ​​the second protrusion 412 is greater than three times the area of ​​the first protrusions 411.

[0117] In this embodiment, the area of ​​the second protrusion 412 is set to be multiple times the area of ​​the first protrusion 411 to enhance the current transmission capability of the transmission electrode 40 and ensure the photoelectric conversion efficiency of the solar cell.

[0118] In a preferred embodiment of this application, the angle between the extending direction of the second protrusion 412 and the extending direction of the transmission electrode 40 is set to be less than or equal to 30 degrees. Since the current transmission direction in the transmission electrode 40 is typically the same as the extending direction of the transmission electrode 40, setting the angle between the extending direction of the second protrusion 412 and the extending direction of the transmission electrode 40 to be less than or equal to 30 degrees can further enhance the current transmission capability of the transmission electrode 40 and improve the photoelectric conversion efficiency of the solar cell.

[0119] Optionally, in this embodiment of the application, the distance between the center points of two adjacent recesses 43 is greater than or equal to 20 μm and less than or equal to 100 μm.

[0120] As shown in Figures 1 to 3, taking a circular projection of the recessed portion 43 onto the plane of the base 10 as an example, the distance between the centers of two adjacent circles is greater than or equal to 20 μm and less than or equal to 100 μm. As shown in Figures 4 to 6, taking a near-square projection of the recessed portion 43 onto the plane of the base 10 as an example, the distance between the center points of two adjacent squares is greater than or equal to 20 μm and less than or equal to 100 μm. Here, a near-square is a quadrilateral with four arc-shaped sides and two opposite sides symmetrical. As shown in Figure 7, taking a near-equilateral triangle projection of the recessed portion 43 onto the plane of the base 10 as an example, the distance between the center points of two adjacent equilateral triangles is greater than or equal to 20 μm and less than or equal to 100 μm. Here, a near-equilateral triangle is a triangle with three sides of equal arc shape. As shown in Figure 8, taking an elliptical projection of the recessed portion 43 onto the plane of the base 10 as an example, the distance between the center points of two adjacent ellipses is greater than or equal to 20 μm and less than or equal to 100 μm. Among them, the elliptical structure can be that the two sides opposite to each other in the direction of the major axis and / or minor axis of the ellipse are pointed.

[0121] In the embodiments shown in Figures 1 to 7, multiple recesses 43 are arranged sequentially in the first direction A and the second direction B. In the embodiment shown in Figure 8, multiple recesses 43 are arranged in a circular array along the periphery of the protrusion 41. Specifically, the recesses 43 are approximately elliptical in shape; three recesses 43 are evenly arranged around the periphery of the third protrusion 413 with a triangular star structure, and six recesses 43 are evenly arranged around the periphery of the fourth protrusion 414 with a hexagonal star structure. In other words, there are various forms in which the array of multiple recesses 43 can be arranged, and these will not be listed here.

[0122] In this embodiment, the distance between the center points of two adjacent recesses 43 is set to be greater than or equal to 20 μm and less than or equal to 100 μm to reduce the amount of material used in the transmission electrode 40 and reduce the manufacturing cost of the transmission electrode 40. Simultaneously, it also avoids the situation where a large distance between two adjacent protrusions 41 affects the current transmission efficiency of the transmission electrode 40.

[0123] For example, the distance between the center points of two adjacent recesses 43 can be set to 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, etc.

[0124] Optionally, along the thickness direction of the solar cell, the distance between the bottom of the recess 43 and the top of the protrusion 41 is a first depth, and the ratio of the first depth to the distance between the center points of two adjacent recesses 43 is greater than or equal to 0.1 and less than or equal to 1.

[0125] In this embodiment, along the thickness direction of the solar cell, the first depth is the protrusion height of the top of the protrusion 41 relative to the bottom of the recess 43. The ratio of the first depth to the distance between the center points of two adjacent recesses 43 is set to be greater than or equal to 0.1 and less than or equal to 1, thereby optimizing the dimensions of the recesses 43. This further reduces the material usage of the transmission electrode 40, lowers the manufacturing cost of the transmission electrode 40, and simultaneously ensures the current transmission efficiency of the transmission electrode 40, thus guaranteeing the photoelectric conversion efficiency of the photovoltaic module.

[0126] For example, in the embodiments of this application, the ratio of the first depth of the recess 43 relative to the top of the protrusion 41 to the distance between the center points of two adjacent recesses 43 can be set to 0.1, 0.3, 0.5, 0.7, 0.8, 1.0, etc.

[0127] Optionally, along the thickness direction of the solar cell, the thickness of the transmission electrode 40 at the position corresponding to the protrusion 41 is greater than or equal to 9 μm and less than or equal to 50 μm; and / or, along the thickness direction of the solar cell, the thickness of the transmission electrode 40 at the position corresponding to the recess 43 is greater than or equal to 1 μm and less than or equal to 20 μm.

[0128] In this embodiment, along the thickness direction of the solar cell, the thickness of the transmission electrode 40 at the position corresponding to the protrusion 41 is set to be greater than or equal to 9 μm and less than or equal to 50 μm. That is, the sum of the protrusion thickness of the protrusion 41 from one side of the transmission electrode 40 and the thickness of the bottom of the protrusion 41 on the opposite side of the transmission electrode 40 is greater than or equal to 9 μm and less than or equal to 50 μm.

[0129] By implementing the above configuration, not only can the amount of material used in the transmission electrode 40 be reduced, thus lowering its manufacturing cost and helping to reduce the cost of solar cells and enhance their market competitiveness, but the transmission electrode 40 can also achieve higher transmission efficiency, ensuring the photoelectric conversion efficiency of the solar cell.

[0130] For example, along the thickness direction of the solar cell, the thickness of the transmission electrode 40 at the position corresponding to the protrusion 41 can be set to 9μm, 10μm, 20μm, 30μm, 40μm, 50μm, etc.

[0131] In this embodiment of the application, along the thickness direction of the solar cell, the thickness of the transmission electrode 40 at the position corresponding to the recess 43 is set to be greater than or equal to 1 μm and less than or equal to 20 μm.

[0132] In this embodiment, along the thickness direction of the solar cell, the thickness of the transmission electrode 40 at the position corresponding to the recess 43 is set to be greater than or equal to 1 μm and less than or equal to 20 μm, thereby reducing the amount of material used in the transmission electrode 40 and reducing the manufacturing cost of the transmission electrode 40. Furthermore, the transmission electrode 40 corresponding to the recess 43 can be connected to an adjacent protrusion 41, thereby improving the current transmission efficiency of the transmission electrode 40 and enhancing the photoelectric conversion efficiency of the solar cell.

[0133] Optionally, as shown in Figures 1 to 8, the projection of the recessed portion 43 on the plane of the base 10 in the embodiments of this application is at least one of a circular structure, an elliptical structure, a near-elliptical structure, a square structure, a near-square structure, a triangular structure, and a near-triangular structure.

[0134] As shown in Figures 1 to 8, the recessed portion 43 in this embodiment of the application has a projection on the plane where the base 10 is located. This projection can be a circular structure, an elliptical structure, or a square structure, such as a square structure, a rectangular structure, or a near-square structure, where the near-square structure refers to a square structure with each side being arc-shaped. Additionally, a near-triangular structure can refer to a triangular structure with each side being arc-shaped, and a near-elliptical structure can refer to an elliptical structure where the opposite sides of the major axis and / or minor axis are pointed.

[0135] In this embodiment, the projection of the recessed portion 43 onto the plane of the substrate 10 is set to at least one of a circular structure, an elliptical structure, a near-elliptical structure, a square structure, a near-square structure, a triangular structure, and a near-triangular structure. This helps to reduce the amount of material used in the transmission electrode 40, reduce the manufacturing cost of the transmission electrode 40, thereby reducing the cost of the solar cell and enhancing its market competitiveness.

[0136] Optionally, in this embodiment of the application, there are multiple transmission electrodes 40, all of which extend along a third direction C and are arranged at intervals along a fourth direction D; wherein the fourth direction D intersects with the third direction C.

[0137] In this embodiment, there are multiple transmission electrodes 40, each extending along a third direction C and spaced apart along a fourth direction D, to collect the current generated by the substrate 10 through the multiple transmission electrodes 40. Referring to Figures 11 and 12, at least one transmission electrode 40 includes a collector grid line 401 and an electrical connection disk 402, and multiple electrical connection disks 402 are disposed on the collector grid line 401 at intervals along the third direction C.

[0138] When there are multiple collector grid lines 401, multiple electrical connection disks 402 located on different collector grid lines 401 are arranged at intervals along the fourth direction D to form an electrical connection disk group.

[0139] Each electrical connection disk 402 is electrically connected to at least one collector grid line 401 to conduct at least one collector grid line 401 to an external electrical connector, so that the charge carriers collected by at least one collector grid line 401 can be transferred through the electrical connection disk 402 to the external electrical connector, and then transferred to an external circuit through the external electrical connector.

[0140] Multiple protrusions 41 arranged in an array are disposed on the surface of the electrical connection disk 402 away from the base 10. The protrusions 41 on the electrical connection disk 402 have the structure described above, which will not be repeated here.

[0141] The electrical connection disk 402 and the collector grid line 401 have an overlapping area. It can be understood that the electrical connection disk 402 is overlapped on the side of the collector grid line 401 away from the substrate 10 to form the overlapping area. Alternatively, the collector grid line 401 is overlapped on the side of the electrical connection disk 402 away from the substrate 10 to form the overlapping area.

[0142] The array of protrusions 41 not only reduces the material usage and manufacturing cost of the electrical connection disk 402, thereby lowering the cost of the solar cell and enhancing its market competitiveness, but also ensures the carrier transport efficiency of the electrical connection disk 402, thus guaranteeing the photoelectric conversion efficiency of the solar cell.

[0143] Referring to Figure 12, in an embodiment of this application, the area on the collector grid line 401 where the electrical connection disk 402 is not provided has a plurality of non-arrayed protrusions 44 on the surface away from the substrate 10.

[0144] Due to manufacturing process requirements, the areas on the current collector line 401 without electrical connection pads 402 do not have the aforementioned protrusions 41 on the surface away from the substrate 10. However, the surfaces of these areas may not be flat; they may contain non-arrayed protrusions 44. These protrusions 44 may be, for example, arc-shaped structures, trapezoidal structures, or trapezoidal-like structures distributed in one-dimensional or any discrete form. A trapezoidal-like structure refers to a trapezoidal structure with arc-shaped sides, or a trapezoidal structure with chamfered corners.

[0145] In the embodiment shown in Figure 12, these protrusions 44 are arranged at intervals along a third direction C, and recesses 45 are formed between adjacent protrusions 44. That is, multiple protrusions 44 are arranged only in one dimension. It should be understood that the third direction is the extension direction of the current collector grid line 401. In the thickness direction of the cell, the height H2 between the top of the protrusion 44 and the bottom of the adjacent recess 45 is 0.5μm-4μm. Therefore, the distance between the top of the protrusion 41 and the electrical connection pad 402 corresponding to the bottom of the adjacent recess 43 (i.e., the height H1 of the protrusion) is greater than the height H2.

[0146] In the embodiments of this application, the area of ​​the collector grid line 401 where the electrical connection disk 402 is not provided does not have a protrusion 44 on the surface away from the substrate 10, that is, the surface is flat, to ensure the carrier transmission efficiency of the collector grid line 401.

[0147] In the embodiments of this application, the solar cell is a back-contact solar cell.

[0148] When the solar cell is a back-contact solar cell, the first surface of the substrate 10 is the sun-receiving surface facing the sunlight, also known as the front surface. The second surface of the substrate 10 is the back-facing surface facing away from the sunlight, also known as the back surface. Multiple transmission electrodes 40 are disposed on the back surface of the substrate 10, including a positive transmission electrode and a negative transmission electrode. The positive and negative transmission electrodes can be alternately arranged on the back surface of the substrate 10.

[0149] In embodiments of this application, a conductive layer is coated on the surface of the electrical connector 402 away from the substrate 10. The conductive layer can be prepared using solder paste, conductive adhesive, or the like. The conductive layer contains metals such as silver, copper, lead, bismuth, zinc, and nickel. The conductive layer connects the electrical connector 402 to the solder strip.

[0150] Optionally, as shown in Figures 9 and 10, the solar cell disclosed in this application embodiment further includes a passivation layer 20 and a contact electrode 30. The passivation layer 20 is stacked between the substrate 10 and the transmission electrode 40. The contact electrode 30 passes through the passivation layer 20, with one end of the contact electrode 30 electrically connected to the substrate 10 and the other end of the contact electrode 30 electrically connected to the transmission electrode 40.

[0151] As shown in Figures 9 and 10, in this embodiment of the application, a passivation layer 20 is stacked between the substrate 10 and the transmission electrode 40. The passivation layer 20 has insulating properties and protects the substrate 10 to avoid problems such as short circuits in the solar cell.

[0152] It should be noted that the passivation layer 20 in the embodiments of this application includes, but is not limited to, at least one of silicon nitride layer, silicon oxide layer, silicon oxynitride layer, aluminum oxide layer, silicon carbide layer, and amorphous silicon layer.

[0153] In this embodiment, a contact electrode 30 is disposed through the passivation layer 20, with one end of the contact electrode 30 abutting against the substrate 10 and electrically connected to the substrate 10, and the other end of the contact electrode 30 abutting against the transmission electrode 40 and electrically connected to the transmission electrode 40. The contact electrode 30 connects the substrate 10 and the transmission electrode 40, thereby conducting the current generated by the substrate 10 to the transmission electrode 40, and then transmitting the current to the external circuit through the transmission electrode 40.

[0154] It should be noted that the contact electrode 30 in this embodiment can be made of metals such as silver, copper, aluminum, nickel, gold, zinc, tin, and lead. The contact electrode 30 can also be made of metal oxides, metal nitrides, metal carbides, or metal sulfides. For example, the metal oxide can be indium tin oxide, and the metal nitride can be tin nitride, etc. In this embodiment, no excessive restrictions are placed on the specific material of the contact electrode 30; in practical applications, those skilled in the art can choose according to their needs.

[0155] In this embodiment, a point contact technique is used to connect the substrate 10 and the transmission electrode 40. On one hand, this effectively reduces the direct connection area between the transmission electrode 40 and the substrate 10, thereby improving the passivation capability of the substrate 10 surface. On the other hand, the contact electrode 30 can be selected from structures and materials with a low recombination rate after contacting the substrate 10, thus reducing the recombination rate at the contact interface between the contact electrode 30 and the substrate 10. Furthermore, the contact electrode 30 can be made from materials with better contact performance; for example, materials with lower resistance can be used to reduce resistance and improve transmission performance. Finally, since the material cost of the contact electrode 30 is relatively high, the above-mentioned design can reduce the amount of material used in the contact electrode 30, thereby significantly reducing the production cost of the solar cell.

[0156] Optionally, as shown in FIG10, the transmission electrode 40 in this embodiment of the application has a first projection on the plane where the substrate 10 is located, and the contact electrode 30 has a second projection on the plane where the substrate 10 is located, with the second projection falling into the first projection.

[0157] As shown in Figure 10, in this embodiment, the transmission electrode 40 has a first projection on the plane of the substrate 10, and the contact electrode 30 has a second projection on the plane of the substrate 10, with the second projection falling within the first projection. It can be understood that along the fourth direction D, the width of the transmission electrode 40 is greater than or equal to the width of the contact electrode 30. This allows the contact electrode 30 to connect the substrate 10 and the transmission electrode 40, thereby ensuring the current transmission efficiency of the transmission electrode 40 and guaranteeing the photoelectric conversion efficiency of the solar cell.

[0158] Optionally, as shown in FIG10, in this embodiment of the application, the width of the transmission electrode 40 along the fourth direction D is greater than or equal to 60 μm; and / or, the width of the contact electrode 30 along the fourth direction D is greater than or equal to 10 μm and less than or equal to 40 μm.

[0159] As shown in Figure 10, in this embodiment, along the fourth direction D, the width of the transmission electrode 40 is set to be greater than or equal to 60 μm, and the width of the contact electrode 30 is set to be greater than or equal to 10 μm and less than or equal to 40 μm. Even if the transmission electrode 40 is significantly offset from the contact electrode 30 along the fourth direction D, the transmission electrode 40 can still be electrically connected to the contact electrode 30, giving the transmission electrode 40 good current transmission capability, thereby ensuring the current transmission efficiency of the transmission electrode 40 and the photoelectric conversion efficiency of the solar cell. Although the width of the transmission electrode 40 is relatively wide, because there are multiple arrayed protrusions 41 on the side of the transmission electrode 40 away from the substrate 10, the amount of paste used in the transmission electrode 40 can be reduced without affecting the transmission efficiency of the transmission electrode 40, thus reducing the cost of the paste and helping to reduce the manufacturing cost of the solar cell and enhance its market competitiveness.

[0160] For example, along the fourth direction D, the width of the transmission electrode 40 can be set to 60μm, 65μm, 70μm, 75μm, 80μm, 85μm, 90μm, etc. Along the fourth direction D, the width of the contact electrode 30 can be set to 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, etc.

[0161] Optionally, as shown in FIG9, the substrate 10 in this embodiment of the application has a first surface and a second surface disposed opposite to each other, the passivation layer 20 is stacked on the first surface of the substrate 10, and / or the passivation layer 20 is stacked on the second surface of the substrate 10.

[0162] As shown in Figure 9, the substrate 10 in this embodiment has a first surface and a second surface disposed opposite to each other, taking the first surface of the substrate 10 as the front and the second surface as the back as an example. The passivation layer 20 may be stacked only on the first surface of the substrate 10, and the transmission electrode 40 may also be disposed only on the first surface of the substrate 10 with the passivation layer 20. Alternatively, the passivation layer 20 may be stacked only on the second surface of the substrate 10, and the transmission electrode 40 may also be disposed only on the second surface of the substrate 10 with the passivation layer 20, resulting in a back-contact solar cell. Alternatively, the passivation layer 20 may be stacked on both the first and second surfaces of the substrate 10, thus the transmission electrode 40 may be disposed on both the first and second surfaces of the substrate 10 with the passivation layer 20, resulting in a bifacial solar cell.

[0163] Optionally, along the second direction B, the distance between the center points of two adjacent protrusions 41 is W1; along the fourth direction D, the width of the contact electrode 30 is W2, satisfying -2 < lg(W2 / W1) < 2; wherein, the second direction B intersects the third direction C, and the fourth direction D is perpendicular to the third direction C.

[0164] In this embodiment, along the second direction B, the distance between the center points of two adjacent protrusions 41 is set to W1, and along the fourth direction D, the width of the contact electrode 30 is set to W2, satisfying -2 < lg(W2 / W1) < 2. This setting reduces the transmission resistance between the contact electrode 30 and the transmission electrode 40, ensuring current transmission efficiency and improving the photoelectric conversion efficiency of the solar cell.

[0165] For example, lg(W2 / W1) can be set to -2, -1.5, -1, 0, 0.5, 1, 2, etc.

[0166] In a preferred embodiment of this application, -1 < lg(W2 / W1) < 1 is satisfied. This further reduces the transmission resistance between the contact electrode 30 and the transmission electrode 40, ensuring current transmission efficiency and improving the photoelectric conversion efficiency of the solar cell.

[0167] For example, lg(W2 / W1) can be set to -1, -0.8, -0.5, -0.2, 0, 0.2, 0.5, 0.7, 1, etc.

[0168] Optionally, W2 ≥ 30 μm must be satisfied.

[0169] In this embodiment, along the fourth direction D, the width W2 of the contact electrode 30 can be set to be greater than or equal to 30 μm to ensure that the contact electrode 30 can make good contact with the transmission electrode 40, and the current can be better transmitted from the contact electrode 30 to the transmission electrode 40, thus ensuring the photoelectric conversion efficiency of the solar cell.

[0170] For example, along the fourth direction D, the width W2 of the contact electrode 30 can be set to 30μm, 32μm, 35μm, 38μm, 40μm, etc.

[0171] Optionally, W1 < 2W2 must be satisfied.

[0172] In this embodiment, the distance W1 between the center points of two adjacent protrusions 41 is set to be less than twice the width W2 of the contact electrode 30, so as to ensure that the contact electrode 30 is at least partially located below the protrusion 41, that is, the contact electrode 30 and the protrusion 41 of the transmission electrode 40 are in contact. The protrusion 41 is thicker and has a smaller transmission resistance, thereby reducing the resistance during current transmission and increasing the current transmission efficiency, which helps to improve the photoelectric conversion efficiency of the solar cell.

[0173] Optionally, the distance between the center points of two adjacent recesses 43 is W3, and the width of the contact electrode 30 along the fourth direction D is W2, satisfying W2-W3>10μm.

[0174] In this embodiment, the difference between the width W2 of the contact electrode 30 and the distance W3 between the center points of two adjacent recesses 43 is set to be greater than 10 μm, so that the contact electrode 30 is located below more protrusions 41, and the contact electrode 30 and more protrusions 41 of the transmission electrode 40 are in contact. The protrusions 41 are thicker and have lower transmission resistance, thereby reducing the resistance during current transmission and increasing the current transmission efficiency, which helps to improve the photoelectric conversion efficiency of the solar cell.

[0175] For example, the difference between the width W2 of the contact electrode 30 and the distance W3 between the center points of two adjacent recesses 43 can be set to 11μm, 12μm, 13μm, 14μm, 15μm, etc.

[0176] In one optional implementation, as shown in FIG10, the contact electrode 30 in this embodiment of the application is a strip-shaped structure. The contact electrode 30 extends along a third direction C, and the third direction C is the same as the extension direction of the transmission electrode 40.

[0177] In another alternative implementation, as shown in FIG10, the projection of the contact electrode 30 on the plane of the substrate 10 in this embodiment can be circular, square, elliptical, or square-like.

[0178] In this configuration, multiple contact electrodes 30 are arranged at intervals along a third direction C to form a group of contact electrodes 30, where the third direction C is the same as the extending direction of the transmission electrode 40. Alternatively, multiple contact electrodes 30 are arranged at intervals along a third direction C to form multiple groups of contact electrodes 30, where the multiple groups of contact electrodes 30 are arranged at intervals along a fourth direction D, where the fourth direction D intersects with the third direction C.

[0179] Of course, as shown in Figure 10, the shape of the contact electrode 30 can also include the two types mentioned above, and the contact electrodes 30 of the two types are arranged at intervals along the third direction C.

[0180] The above are just a few examples of specific structures for the contact electrode 30 and are not intended to limit this application. In practical applications, those skilled in the art can customize the specific structure of the contact electrode 30 as needed.

[0181] Optionally, in this embodiment, the substrate 10 includes a first surface and a second surface disposed opposite to each other. The second surface has a first electrode region and a second electrode region disposed adjacent to each other, and the polarities of the first electrode region and the second electrode region are opposite. The transmission electrode 40 includes a first transmission electrode and a second transmission electrode. The first transmission electrode is disposed in the first electrode region and is electrically connected to the first electrode region. The second transmission electrode is disposed in the second electrode region and is electrically connected to the second electrode region. In this embodiment, along the thickness direction of the solar cell, the height of the protrusion 41 in the first transmission electrode and the height of the protrusion 41 in the second transmission electrode are the same or different.

[0182] When the solar cell is a back-contact solar cell, the first surface of the substrate 10 is the sunlight-receiving surface, also known as the front side. The second surface of the substrate 10 is the back-contact surface, also known as the back side. The second surface has multiple adjacent first and second electrode regions, each extending along a third direction C and alternately arranged along a fourth direction D. For example, the first electrode region is a P region and the second electrode region is an N region, or vice versa.

[0183] The contact electrode includes a first contact electrode and a second contact electrode. The first contact electrode passes through the passivation layer, and one end of the first contact electrode is connected to a first electrode region. A first transmission electrode is disposed on the first contact electrode and electrically connected to the other end of the first contact electrode. The second contact electrode passes through the passivation layer, and one end of the second contact electrode is connected to a second electrode region. A second transmission electrode is disposed on the second contact electrode and electrically connected to the other end of the second contact electrode.

[0184] It should be noted that in this embodiment, both the first and second transmission electrodes have multiple protrusions 41 on the side away from the substrate 10, and these protrusions 41 are arranged in an array. The height of the protrusions 41 included in the first transmission electrode and the height of the protrusions 41 included in the second transmission electrode can be the same or different. This embodiment does not impose specific limitations on this. In practical applications, technicians can adjust the heights of the protrusions 41 included in the first and second transmission electrodes according to the current collection requirements, thereby further controlling the amount of material used in the transmission electrode 40, reducing the production cost of the solar cell, and enhancing the market competitiveness of the solar cell.

[0185] Optionally, the distance between the center points of two adjacent recesses 43 in the first transmission electrode is different from the distance between the center points of two adjacent recesses 43 in the second transmission electrode.

[0186] In this embodiment, the distance between the center points of two adjacent recesses 43 in the first transmission electrode is different from the distance between the center points of two adjacent recesses 43 in the second transmission electrode. For example, the distance between the center points of two adjacent recesses 43 in the first transmission electrode is greater than the distance between the center points of two adjacent recesses 43 in the second transmission electrode. Alternatively, the distance between the center points of two adjacent recesses 43 in the first transmission electrode is less than the distance between the center points of two adjacent recesses 43 in the second transmission electrode.

[0187] In this embodiment, by setting the distance between the center points of two adjacent recesses 43 in the first transmission electrode to be different from the distance between the center points of two adjacent recesses 43 in the second transmission electrode, the distance between the center points of two adjacent recesses 43 in the first transmission electrode and the distance between the center points of two adjacent recesses 43 in the second transmission electrode are made more suitable, thereby further controlling the amount of material used in the transmission electrode 40, reducing the production cost of the solar cell, and enhancing the market competitiveness of the solar cell.

[0188] This application also discloses a photovoltaic module, which includes the solar cells described in the above embodiments.

[0189] It should be noted that in this embodiment, the photovoltaic module includes solar cells with the same structure as those described in the above embodiments, and their beneficial effects are similar. Further details will not be repeated here.

[0190] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0191] Although optional embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the optional embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0192] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used merely to distinguish one entity from another, and do not necessarily require or imply any such actual relationship or order between these entities. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or terminal device that includes that element.

[0193] The technical solutions provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the principles and implementation methods of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A solar cell, characterized in that, include: Base; A transmission electrode is disposed on the surface of the substrate and electrically connected to the substrate. A plurality of protrusions are sequentially disposed on the side of the transmission electrode away from the substrate. The plurality of protrusions are arranged in an array, and adjacent protrusions are at least partially connected.

2. The solar cell according to claim 1, characterized in that, Multiple protrusions are arranged sequentially along a second direction to form a group of protrusions, and multiple groups of protrusions are arranged sequentially along a first direction; wherein, the extension direction of the transmission electrode is a third direction, the second direction is parallel to or intersects the third direction, and the first direction intersects the second direction and the third direction.

3. The solar cell according to claim 2, characterized in that, The second direction and the third direction have a first included angle, which is greater than or equal to 0 degrees and less than or equal to 60 degrees.

4. The solar cell according to claim 3, characterized in that, The first included angle is greater than or equal to 0 degrees and less than or equal to 45 degrees.

5. The solar cell according to claim 3 or 4, characterized in that, There is a second angle between the first direction and the second direction, and the second angle is less than or equal to 90 degrees.

6. The solar cell according to any one of claims 1-4, characterized in that, The plurality of protrusions includes a plurality of spaced-apart third protrusions and a plurality of spaced-apart fourth protrusions; Any of the third protrusions is at least partially connected to the plurality of fourth protrusions, and the plurality of fourth protrusions connected to the third protrusions are arranged in a circular array along the circumference of the third protrusion; Each of the fourth protrusions is at least partially connected to a plurality of the third protrusions, and the plurality of the third protrusions connected to the fourth protrusions are arranged in a circular array along the circumference of the fourth protrusion.

7. The solar cell according to any one of claims 1-4, characterized in that, The adjacent protrusions enclose a first region, and the recess of the transmission electrode corresponds to the first region.

8. The solar cell according to claim 7, characterized in that, Along the thickness direction of the solar cell, the height of the protrusion is greater than or equal to 5 μm and less than or equal to 30 μm; the height of the protrusion is the distance between the top of the protrusion and the bottom of the recess.

9. The solar cell according to claim 7, characterized in that, Along the thickness direction of the solar cell, the height of the protrusion is greater than or equal to 5 μm and less than or equal to 15 μm.

10. The solar cell according to any one of claims 1-4, characterized in that, The projection of the protrusion onto the plane of the base is at least one of a cross-shaped structure, a hexagonal structure, or a triangular structure.

11. The solar cell according to claim 2, characterized in that, The line connecting the center points of each of the protrusions in each group is on a straight line.

12. The solar cell according to claim 7, characterized in that, The number of the recesses is multiple, and the multiple recesses are arranged in an array.

13. The solar cell according to claim 7, characterized in that, The recessed portion includes a first recessed portion and a second recessed portion, wherein the area of ​​the second recessed portion is multiple times the area of ​​the first recessed portion; And / or, the protrusion includes a first protrusion and a second protrusion, wherein the area of ​​the second protrusion is multiple times the area of ​​the first protrusion.

14. The solar cell according to claim 7, characterized in that, The distance between the center points of two adjacent recesses is greater than or equal to 20 μm and less than or equal to 100 μm.

15. The solar cell according to claim 7, characterized in that, Along the thickness direction of the solar cell, the distance between the bottom of the recess and the top of the protrusion is a first depth, and the ratio of the first depth to the distance between the center points of two adjacent recesses is greater than or equal to 0.1 and less than or equal to 1.

16. The solar cell according to claim 7, characterized in that, Along the thickness direction of the solar cell, the thickness of the transmission electrode at the position corresponding to the protrusion is greater than or equal to 9 μm and less than or equal to 50 μm. And / or, along the thickness direction of the solar cell, the thickness of the transmission electrode at the position corresponding to the recess is greater than or equal to 1 μm and less than or equal to 20 μm.

17. The solar cell according to claim 7, characterized in that, The projection of the recessed portion onto the plane of the base is at least one of the following: circular structure, elliptical structure, quasi-elliptical structure, square structure, quasi-square structure, triangular structure, and quasi-triangular structure.

18. The solar cell according to any one of claims 1-17, characterized in that, The number of transmission electrodes is multiple, and each of the multiple transmission electrodes extends along a third direction and is arranged at intervals along a fourth direction; the fourth direction intersects with the third direction. Wherein, at least one of the transmission electrodes includes a collector grid line and an electrical connection disk, wherein a plurality of electrical connection disks are arranged at intervals along the third direction on the collector grid line, and a plurality of protrusions arranged in an array are disposed on the surface of the electrical connection disk away from the substrate; Preferably, there are multiple collector grid lines, and multiple electrical connection disks located on different collector grid lines are spaced apart along the fourth direction to form an electrical connection disk group.

19. The solar cell according to claim 18, characterized in that, In the area on the current collector line where no electrical connection pad is provided, multiple non-arrayed protrusions are provided on the surface away from the substrate.

20. The solar cell according to claim 18, characterized in that, The solar cell is a back-contact solar cell.

21. The solar cell according to claim 20, characterized in that, The electrical connection disk has a conductive layer on the side surface away from the substrate.

22. The solar cell according to any one of claims 1-21, characterized in that, The solar cell also includes: A passivation layer is stacked between the substrate and the transmission electrode; A contact electrode is disposed through the passivation layer, with one end of the contact electrode electrically connected to the substrate and the other end of the contact electrode electrically connected to the transmission electrode.

23. The solar cell according to claim 22, characterized in that, The transmission electrode has a first projection on the plane of the substrate, and the contact electrode has a second projection on the plane of the substrate, the second projection falling within the first projection.

24. The solar cell according to claim 22, characterized in that, Along the fourth direction, the width of the transmission electrode is greater than or equal to 60 μm; And / or, along the fourth direction, the width of the contact electrode is greater than or equal to 10 μm and less than or equal to 40 μm.

25. The solar cell according to claim 22, characterized in that, The substrate has a first surface and a second surface disposed opposite to each other, the passivation layer is stacked on the first surface of the substrate, and / or the passivation layer is stacked on the second surface of the substrate.

26. The solar cell according to claim 22, characterized in that, Along the second direction, the distance between the center points of two adjacent protrusions is W1; Along the fourth direction, the width of the contact electrode is W2, which satisfies -2 < lg(W2 / W1) < 2; Wherein, the second direction intersects with the third direction, and the fourth direction is perpendicular to the third direction.

27. The solar cell according to claim 26, characterized in that, The condition is satisfied that -1 < lg(W2 / W1) < 1.

28. The solar cell according to claim 26, characterized in that, The W2 ≥ 30 μm requirement is met.

29. The solar cell according to claim 26, characterized in that, The condition is satisfied that W1 < 2W2.

30. The solar cell according to claim 26, characterized in that, The distance between the center points of two adjacent recesses is W3, and the width of the contact electrode along the fourth direction is W2, satisfying W2-W3>10μm.

31. The solar cell according to claim 7, characterized in that, The substrate includes a first surface and a second surface disposed opposite to each other. The second surface has a first electrode region and a second electrode region disposed adjacent to each other, and the polarities of the first electrode region and the second electrode region are opposite. The transmission electrode includes a first transmission electrode and a second transmission electrode. The first transmission electrode is disposed in the first electrode region and is electrically connected to the first electrode region. The second transmission electrode is disposed in the second electrode region and is electrically connected to the second electrode region. Wherein, along the thickness direction of the solar cell, the height of the protrusion in the first transmission electrode is the same as or different from the height of the protrusion in the second transmission electrode.

32. The solar cell according to claim 31, characterized in that, The distance between the center points of two adjacent recesses in the first transmission electrode is different from the distance between the center points of two adjacent recesses in the second transmission electrode.

33. A photovoltaic module, characterized in that, The photovoltaic module includes the solar cell according to any one of claims 1-32.

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