A back contact solar cell and a back contact solar cell module

Abstract

The present disclosure relates to the technical field of solar cells, and discloses a back contact solar cell and a back contact solar cell module. The back contact solar cell comprises a base layer, a first semiconductor layer, a second semiconductor layer, a first electrode and a protective glue structure. The back light surface of the base layer comprises first regions and second regions which are alternately and spacedly arranged along a first direction. The height of the first regions is greater than that of the second regions. The first semiconductor layer is located on the surface of the first regions, and the second semiconductor layer is located on the surface of the second regions. The surface of the first semiconductor layer protrudes from the surface of the second semiconductor layer. The first electrode is located on the surface of the first semiconductor layer. The protective glue structure is located on the surface of the first semiconductor layer, and is located on the side of the first auxiliary grid lines and / or the side of the first main grid lines. The thickness of the protective glue structure is greater than that of the first electrode. The present disclosure can improve the optical performance of the cell, avoid scratches between the cell pieces, and reduce the height and cost of the protective glue structure.

Description

Technical Field

[0001] This disclosure relates to the field of solar cell technology, specifically to a back-contact solar cell and a back-contact solar cell module. Background Technology

[0002] In the packaging process of back-contact batteries, spacers are often inserted between the cells to prevent scratches and protect the battery surface. However, the consumption of a large amount of spacers undoubtedly increases the cost of consumables. To reduce the amount of spacers used between cells, existing processes typically add a printing and curing step for a surface protective adhesive (organic system) after the back-contact battery is printed and sintered. This process is less expensive and ultimately forms a protective adhesive barrier layer on the surface of the cells, preventing scratches between cells in subsequent processes.

[0003] However, this method still has some problems. For example, in order to effectively protect the batteries from scratches, the amount of protective adhesive used on the front is often large. This not only increases the amount of protective adhesive used and the cost, but also leads to increased parasitic absorption of light by the protective adhesive on the front, reducing the optical performance of the battery.

[0004] Therefore, a solution is needed that can prevent the cells from being scratched, maintain the optical performance of the battery, and reduce costs. Summary of the Invention

[0005] This disclosure provides a back-contact solar cell and a back-contact solar cell module to solve the problems in related technologies where the protective adhesive is applied to the light-receiving surface, causing a decrease in the optical performance of the cell, as well as the large amount of protective adhesive used and the high cost.

[0006] In a first aspect, this disclosure provides a back-contact solar cell, comprising: The substrate includes a light-receiving surface and a backlighting surface disposed opposite to each other; the backlighting surface of the substrate includes a first region and a second region arranged alternately along a first direction, wherein the height of the first region is greater than the height of the second region. A first semiconductor layer and a second semiconductor layer are alternately disposed on the back surface side of the substrate layer along a first direction; the first semiconductor layer is located on the surface of a first region, and the second semiconductor layer is located on the surface of a second region; the surface of the first semiconductor layer protrudes from the surface of the second semiconductor layer. A first electrode is located on the surface of a first semiconductor layer. The first electrode includes intersecting first sub-gate lines and first main gate lines, wherein the first main gate line extends along a second direction, the first sub-gate line extends along a first direction, and the first direction intersects with the second direction; each first main gate line intersects with multiple parallel first sub-gate lines. A protective adhesive structure is located on the side surface of the first semiconductor layer facing away from the substrate layer; the protective adhesive structure is located on the side of the first sub-gate line and / or on the side of the first main gate line; the thickness of the protective adhesive structure is greater than the thickness of the first electrode.

[0007] Beneficial Effects: The back-contact solar cell provided in this disclosure, on the one hand, by placing the protective adhesive structure on the backlight side, can avoid parasitic absorption of incident light by the protective adhesive on the light-receiving side, thereby improving the optical performance of the cell. On the other hand, by placing the protective adhesive structure on the surface of the first semiconductor layer protruding from the second semiconductor layer, the protective adhesive structure is positioned at a higher height on the backlight side, which can reduce the height and volume of the protective adhesive structure. Furthermore, when the cells are stacked, the protective adhesive structure can contact adjacent cells and provide support, thus preventing scratches between cells even with the protective adhesive structure placed in a portion of the backlight side. This reduces the manufacturing and storage costs of the cell and improves the reliability of the back-contact solar cell. Moreover, the protective adhesive structure located on the side of the first sub-grid line and / or on the side of the first main grid line can better protect the first electrode from scratches. The thickness of the protective adhesive structure is greater than the thickness of the first electrode, ensuring that when the cells are stacked, the protective adhesive structure on the backlight side contacts adjacent cells, preventing direct contact between the first electrode and adjacent cells and maintaining a gap, effectively avoiding damage to the first electrode.

[0008] In one alternative embodiment, a first pad is provided at the intersection of the first main gate line and a portion of the first sub-gate line; The protective adhesive structure is disposed on the surface of the first semiconductor layer between adjacent first pads and on both sides of the extension direction of the first main gate line.

[0009] Beneficial effects: The back-contact solar cell provided in this disclosure does not perform welding functions in the area between adjacent first pads and on both sides of the first main grid line, and has a large area available for adhesive application. Setting a protective adhesive structure in this area can obtain a large support area, while avoiding the location of the first pads, which can improve the support and protection performance of the protective adhesive, thereby improving the reliability of the back-contact solar cell.

[0010] In one alternative embodiment, the protective adhesive structure is discontinuously or continuously distributed along the extension direction of the first main gate line between adjacent first pads. The protective adhesive structure has a first spacing with the adjacent first main gate line; a preset solder ribbon area is provided on the surface of the first semiconductor layer exposed between the protective adhesive structure and the adjacent first main gate line.

[0011] Beneficial Effects: The back-contact solar cell provided in this disclosure has a protective adhesive structure located on both sides of the extension direction of the first main grid line, and a pre-set solder ribbon area between the protective adhesive structure and the adjacent first main grid line. This allows the protective adhesive structure to be misaligned with the pre-set solder ribbon area used for setting the solder ribbon, thereby improving the support and protection of adjacent cells without affecting the interconnection lines between cells, preventing damage to the cell surface, and improving the reliability of the back-contact solar cell. Furthermore, when the protective adhesive structure is discontinuously distributed along the extension direction of the first main grid line, the stress generated by thermal expansion and contraction during the curing process is divided into multiple segments, reducing the continuous accumulation of stress on the cell. This also reduces the amount and volume of protective adhesive used, thereby lowering costs. When the protective adhesive structure is continuously distributed along the extension direction of the first main grid line, the support area of ​​the protective adhesive structure can be increased, improving support and protection performance.

[0012] In one alternative embodiment, the back-contact solar cell further includes: An insulating adhesive structure that at least partially covers the first sub-grid wires; The thickness of the protective adhesive structure is greater than the thickness of the insulating adhesive structure; the thickness of the insulating adhesive structure is greater than the thickness of the first subgrid line.

[0013] Beneficial effects: The back-contact solar cell provided in this disclosure has an insulating adhesive structure that at least partially covers the first grid lines, which electrically isolates the first grid lines from the second semiconductor layer. This prevents short circuits caused by the solder ribbons on the surface of the second semiconductor layer contacting the first grid lines, thereby solving the problem of short circuits caused by solder ribbons overlapping electrodes of different polarities during module welding and improving the electrical connection reliability of the back-contact solar cell. The thickness of the protective adhesive structure is greater than that of the insulating adhesive structure, and the protective adhesive structure is still a structure with a higher height on the back side. When the cells are stacked, the protective adhesive structure serves as a support and protection structure between adjacent cells, which can simultaneously protect the first electrode and the insulating adhesive structure from damage.

[0014] In one alternative implementation, the protective adhesive structure is located at least on both sides of the extension direction of the first sub-grid line; The protective adhesive structure is distributed intermittently or continuously along the extension direction of the first sub-grid line; The insulating adhesive structure covers at least one end of the first sub-grid line away from the first main grid line.

[0015] Beneficial Effects: The back-contact solar cell provided by this disclosure has a protective adhesive structure located at least on both sides of the extension direction of the first sub-grid line. This allows the protective adhesive structure to be evenly distributed across various positions on the back surface, improving the stress uniformity of the protective adhesive structure. Simultaneously, the arrangement of the protective adhesive structure along the extension direction of the first sub-grid line better protects the second sub-grid line, preventing damage and improving the protection precision of the protective adhesive structure. Furthermore, when the protective adhesive structure is discontinuously distributed along the extension direction of the first sub-grid line, the stress generated during the curing process due to thermal expansion and contraction is divided into multiple segments, reducing the continuous accumulation of stress on the cell. This also reduces the amount and volume of protective adhesive used, thereby lowering costs. When the protective adhesive structure is continuously distributed along the extension direction of the first sub-grid line, the support area of ​​the protective adhesive structure can be increased, improving support and protection performance. In addition, the insulating adhesive structure covers the end of the first sub-grid line furthest from the first main grid line, covering the end of the first sub-grid line that is close to the electrode of opposite polarity. This avoids short circuits caused by solder ribbons overlapping with electrodes of different polarities during module welding, improving the electrical connection reliability of the back-contact solar cell.

[0016] In one alternative implementation, a protective adhesive structure covers the sides and surface of the first subgrid line; The insulating adhesive structure is located on both sides of the extension direction of the first sub-grid line and covers the side of the protective adhesive structure away from the first sub-grid line.

[0017] Beneficial effects: The back-contact solar cell provided in this disclosure has a protective adhesive structure covering the area around the first grid line, and an insulating adhesive structure covering the outer side of the protective adhesive structure. The insulating adhesive structure can increase the support area of ​​the protective adhesive structure, prevent the protective adhesive structure from shifting and deforming, improve the stability and support of the protective adhesive structure, and thus improve the support and protection performance of the protective adhesive structure.

[0018] In one alternative embodiment, the insulating adhesive structure covers the sides and surfaces of a portion of the first subgrid line; The protective adhesive structure is located on both sides of the extension direction of the first sub-grid line and covers the side of the insulating adhesive structure away from the first sub-grid line.

[0019] Beneficial effects: The back-contact solar cell provided by this disclosure has an insulating adhesive structure covering the sides and surfaces of the first grid lines. This provides a relatively good insulating adhesive structure between the first grid lines and the outside, solving the problem of leakage risk caused by insufficient insulation and density when the protective adhesive directly contacts the first grid lines. This further improves the electrical connection reliability of the back-contact solar cell. The protective adhesive structure is located on the outer side of the insulating adhesive structure and serves as a spacer support, which can simultaneously protect the first electrode and the insulating adhesive structure from damage.

[0020] In one alternative embodiment, the back-contact solar cell further includes: The second electrode is located on the surface of the second semiconductor layer. The second electrode includes a second sub-gate line and a second main gate line. The first main gate line and the second main gate line are arranged alternately along a first direction and both extend along a second direction. The first sub-gate line and the second main gate line are arranged alternately along the second direction and both extend along the first direction. The first direction and the second direction intersect. Back-contact solar cells also include: An auxiliary protective adhesive structure is located on the surface of the second semiconductor layer facing away from the substrate layer. The auxiliary protective adhesive structure is located on the side of the second sub-gate line and / or on the side of the second main gate line; the thickness of the auxiliary protective adhesive structure is greater than the thickness of the second electrode.

[0021] Beneficial effects: The back-contact solar cell provided in this disclosure, by setting an auxiliary protective adhesive structure on the surface of the second semiconductor layer, can make the distribution of support protection points on the back surface more dispersed, thereby further improving the reliability of the back-contact solar cell; the thickness of the auxiliary protective adhesive structure is greater than the thickness of the second electrode, so that when the cells are stacked, the auxiliary protective adhesive structure contacts the adjacent cells, so that the second electrode and the adjacent cells do not directly contact each other but maintain a gap, which can effectively avoid damage to the second electrode.

[0022] In one alternative embodiment, the back-contact solar cell further includes: The protective adhesive bumps on the front are located on the light-receiving surface of the substrate and are set in accordance with the protective adhesive structure; the projection of the protective adhesive structure on the substrate covers the projection of the protective adhesive bumps on the substrate.

[0023] Beneficial effects: The back-contact solar cell provided in this disclosure, by obtaining front protective adhesive protrusions at positions corresponding to the light-receiving surface and the protective adhesive structure, can provide support points on the light-receiving side of the stacked solar cells, further improving the scratch phenomenon and enhancing the reliability of the back-contact solar cell; by having the front protective adhesive protrusions correspond to the protective adhesive structure and their projections overlap, the area of ​​the light-receiving surface that is blocked can be limited to the vicinity of the projection range of the protective adhesive structure, which can significantly reduce the blocking area.

[0024] In one alternative implementation, the first semiconductor layer is a P-type semiconductor layer; the second semiconductor layer is an N-type semiconductor layer.

[0025] Beneficial effects: In the back-contact solar cell provided by this disclosure, the height of the first region corresponding to the P-type semiconductor layer is greater than the height of the second region corresponding to the N-type semiconductor layer, and the surface of the P-type semiconductor layer protrudes from the surface of the N-type semiconductor layer. By setting a protective adhesive structure on the surface of the P-type semiconductor layer, the protective adhesive structure is located at the most protruding and easily scratched position on the backlight surface, which better protects the P-type semiconductor layer when the cells are stacked. It can also reduce the height and volume of the protective adhesive structure, reduce the manufacturing cost and storage cost of the cell, and thus achieve the effect of avoiding scratches between cells when a protective adhesive structure is set in a part of the backlight surface, thereby improving the reliability of the back-contact solar cell.

[0026] In one optional embodiment, the first semiconductor layer is a first doped polysilicon layer, and the second semiconductor layer is a second doped polysilicon layer. Back-contact solar cells also include: The first tunneling oxide layer is located between the first semiconductor layer and the substrate layer; The second tunneling oxide layer is located between the second semiconductor layer and the substrate layer; An isolation groove is located between adjacent first and second semiconductor layers and extends into the substrate layer; the isolation groove is also located between adjacent first and second tunneling oxide layers. The isolation grooves separate adjacent first and second semiconductor layers, and also separate adjacent first and second tunneling oxide layers.

[0027] Beneficial effects: The back-contact solar cell provided in this disclosure has a first tunneling oxide layer located between a first semiconductor layer and a substrate layer, and a second tunneling oxide layer located between a second semiconductor layer and a substrate layer. This can reduce the carrier transport barrier and improve the carrier transport efficiency. The isolation groove extends deep into the substrate layer and simultaneously isolates adjacent first and second semiconductor layers, as well as adjacent first and second tunneling oxide layers, so that the two polarity regions are separated from each other laterally. This can prevent the first and second semiconductor layers from conducting. Furthermore, an isolation groove lower than the first and second regions is formed on the backlight surface, resulting in a height difference where the first region is higher than the second region and the second region is higher than the isolation groove. This allows the protective adhesive structure on the surface of the highest first semiconductor layer to protect the entire backlight surface from damage, improving the reliability of the back-contact solar cell.

[0028] Secondly, this disclosure provides a back-contact solar cell module, including the back-contact solar cell of the first aspect or any corresponding embodiment thereof. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the specific embodiments of this disclosure or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of a back-contact solar cell according to an embodiment of the present disclosure; Figure 2 This is a top view schematic diagram of the structure of a back contact solar cell in an embodiment of the present disclosure, in which the protective adhesive structure is located on the side of the first sub-grid. Figure 3 This is a top view schematic diagram of the structure of a back contact solar cell in which the protective adhesive structure is located on the side of the first main grid, according to an embodiment of the present disclosure; Figure 4 This is a schematic diagram of another back-contact solar cell according to an embodiment of the present disclosure; Figure 5A This is a schematic diagram of another embodiment of the present disclosure of a back-contact solar cell in which the insulating adhesive structure is located outside the protective adhesive structure; Figure 5B This is a top view schematic diagram of a continuously distributed protective adhesive structure in a back-contact solar cell according to another embodiment of the present disclosure; Figure 5C This is a top view schematic diagram of the discontinuous distribution of the protective adhesive structure in another embodiment of the present disclosure of a back-contact solar cell; Figure 6A This is a schematic diagram of another embodiment of the present disclosure of a back-contact solar cell in which the protective adhesive structure is located outside the insulating adhesive structure; Figure 6B This is a top view schematic diagram of a continuously distributed protective adhesive structure in a back-contact solar cell according to another embodiment of the present disclosure; Figure 6C This is a top view schematic diagram of a discontinuously distributed protective adhesive structure in a back-contact solar cell according to another embodiment of the present disclosure; Figure 7 This is a schematic diagram of another back-contact solar cell with an auxiliary protective adhesive structure according to an embodiment of the present disclosure; Figure 8 This is a top view schematic diagram of the structure of the auxiliary protective adhesive structure located on the side of the second grid in another embodiment of the back contact solar cell of this disclosure; Figure 9 This is a top view schematic diagram of the structure of an auxiliary protective adhesive structure located on the side of the second main grid in another embodiment of the back contact solar cell of the present disclosure; Figure 10This is a schematic diagram of the structure of the protective adhesive protrusions on the front side of the back contact solar cell in an embodiment of this disclosure.

[0031] Figure label: 10. Basal layer; 101. First region; 102. Second region; 20. First semiconductor layer; 21. First tunneling oxide layer; 30. Second semiconductor layer; 31. Second tunneling oxide layer; 40. Isolation trench; 50. First electrode; 51. First main gate line; 52. First sub-gate line; 511. First pad; 60. Second electrode; 61. Second main gate line; 62. Second auxiliary gate line; 611. Second pad; 70. Protective adhesive structure; 71. Auxiliary protective adhesive structure; 80. Insulating adhesive structure; 90. Front protective adhesive raised dots. Detailed Implementation

[0032] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present disclosure and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present disclosure are shown in the drawings, not the entire structure. All other embodiments obtained by those skilled in the art based on the embodiments of the present disclosure without inventive effort are within the scope of protection of the present disclosure.

[0033] In the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concepts of this disclosure. Various structural schematic diagrams according to embodiments of this disclosure are shown in the accompanying drawings. These drawings are not to scale, and some details are enlarged for clarity and may be omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from actual practices due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed. In the context of this disclosure, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. Additionally, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element.

[0034] In the packaging of back-contact batteries, to prevent scratches between battery cells during packaging and transportation, related technologies involve printing and curing a protective adhesive layer on the light-receiving surface of the battery after printing and sintering the electrodes. This protective adhesive barrier layer replaces the paper separator between the cells. While this method reduces the material cost of the paper separator, the protective adhesive, located on the light-receiving surface, parasitically absorbs light, hindering the battery's absorption of incident light and reducing its optical performance. Furthermore, to ensure that adjacent cells are not scratched, a large amount of protective adhesive is often used on the light-receiving surface, increasing both adhesive consumption and cost.

[0035] During the fabrication of back-contact batteries, a natural structural morphology forms on the back of the battery, with the P-region at its highest position, followed by the N-region, and the isolation region at its lowest position. In related technologies, protective adhesive is applied to both the front and back of the back-contact battery, which increases the amount of adhesive used and the cost.

[0036] Therefore, a solution is needed that can prevent the solar cells from being scratched, avoid degradation of optical performance, and reduce costs.

[0037] Based on the above, this solution provides a back-side patterned protective adhesive printing structure and method. Utilizing the inherent elevation differences on the back surface of the back-contact solar cell, the protective adhesive structure is positioned at a higher elevation on the back surface, allowing it to provide spacing and support without blocking incident light. This effectively solves the parasitic absorption and other abnormalities caused by placing the protective adhesive on the front side, while also significantly reducing the amount of protective adhesive used in printing. The back-contact solar cell provided in this embodiment is described below with reference to the accompanying drawings.

[0038] refer to Figure 1 This embodiment provides a back-contact solar cell, including: a substrate layer 10, a first semiconductor layer 20, a second semiconductor layer 30, and a protective adhesive structure 70. The substrate layer 10 includes a light-receiving surface and a back-lighting surface disposed opposite to each other; the back-lighting surface of the substrate layer 10 includes a first region 101 and a second region 102 arranged alternately along a first direction, the height of the first region 101 being greater than the height of the second region 102. The first semiconductor layer 20 and the second semiconductor layer 30 are alternately disposed on one side of the back-lighting surface of the substrate layer 10 along the first direction, and both the first semiconductor layer 20 and the second semiconductor layer 30 extend along a second direction; the first semiconductor layer 20 is located on the surface of the first region 101, and the second semiconductor layer 30 is located on the surface of the second region 102; the surface of the first semiconductor layer 20 protrudes beyond the surface of the second semiconductor layer 30. The protective adhesive structure 70 is located on the surface of the first semiconductor layer 20 facing away from the substrate layer 10.

[0039] In practice, the protective adhesive structure 70 is positioned at a relatively high height on the backlight surface of the entire battery. When multiple battery cells are stacked, the light-receiving surface of the previous cell faces the backlight surface of the next cell. The protective adhesive structure 70, located at a higher position, contacts the adjacent battery cell before the rest of the backlight surface, creating a gap between adjacent cells. This prevents the rest of the backlight surface from contacting the light-receiving surface of the adjacent cells, thus avoiding scratches caused by friction between adjacent cells. Simultaneously, no protective adhesive is applied to the light-receiving surface, preventing parasitic absorption of incident light and preventing yellowing of the light-receiving surface during long-term outdoor use. Because the spacing effect is provided by the high, localized protrusion, the protective adhesive does not need to be laid across the entire surface, thus reducing the amount of protective adhesive used in printing.

[0040] The protective adhesive structure 70 is suitable for being formed on the battery surface through printing and curing processes. The material of the protective adhesive structure 70 can be an organic colloidal material. The specific adhesive formulation of the protective adhesive structure 70 can be selected according to the printing process, curing temperature, and adhesion requirements to the battery surface; this embodiment does not limit this.

[0041] It should be noted that the heights of the first region 101 and the second region 102 are measured along a direction perpendicular to the light-receiving surface, using the light-receiving surface of the substrate 10 as a reference plane. The greater the distance from the light-receiving surface, the greater the height. The surface of the first semiconductor layer 20 protrudes from the surface of the second semiconductor layer 30, meaning that the side of the first semiconductor layer 20 facing away from the substrate 10 is farther from the light-receiving surface than the side of the second semiconductor layer 30 facing away from the substrate 10. The height difference between the first semiconductor layer 20 and the second semiconductor layer 30 originates from the different processes used for the two polarity regions during battery fabrication. This is a naturally formed morphology on the back surface and does not require additional processes to create this height difference. In this embodiment, all descriptions of orientation refer to the substrate 10 and its light-receiving surface, and are not intended to limit the battery's placement orientation.

[0042] The back-contact solar cell provided in this embodiment, on the one hand, by placing the protective adhesive structure 70 on the backlight side, can avoid parasitic absorption of incident light by the protective adhesive on the light-receiving side, thereby improving the optical performance of the cell; on the other hand, by placing the protective adhesive structure 70 on the surface of the first semiconductor layer 20 protruding from the second semiconductor layer 30, the protective adhesive structure 70 is positioned at a higher height on the backlight side, which can reduce the height and volume of the protective adhesive structure 70, and when the cells are stacked, the protective adhesive structure 70 can contact adjacent cells and play a supporting role. Thus, by placing the protective adhesive structure 70 in a part of the backlight side, the effect of avoiding scratches between cells can be achieved, reducing the manufacturing and storage costs of the cell and improving the reliability of the back-contact solar cell.

[0043] In some alternative implementations, the morphology and distribution of the protective adhesive structure 70 can be flexibly set according to actual needs.

[0044] In some alternative embodiments, the protective adhesive structure 70 is a raised structure, and the vertical cross-section of the protective adhesive structure 70 can be rectangular, conical, semi-circular, etc.

[0045] In practice, the protective adhesive structure 70 protrudes from the surface of the first semiconductor layer 20 to ensure that the top of the protective adhesive structure 70 contacts the adjacent battery cells when the battery cells are stacked, thereby providing support and protection and preventing the battery from being scratched.

[0046] In some alternative embodiments, the protective adhesive structure 70 can be a continuous strip extending along a first direction or a second direction, or it can be a discrete block or dot.

[0047] In some alternative embodiments, the protective adhesive structure 70 can be a continuous strip extending along a first or second direction, which can increase the support area. Specifically, the top view shape of the protective adhesive structure 70 can be a straight or curved strip.

[0048] In some alternative embodiments, a plurality of protective adhesive structures 70 are disposed on each first semiconductor layer 20, and the plurality of protective adhesive structures 70 are discretely distributed at intervals on the surface of the first semiconductor layer 20. By employing an intermittent manner, the stress on individual protective adhesive structures 70 can be reduced, thereby preventing warping of the substrate layer 10.

[0049] In practice, multiple protective adhesive structures 70 can be arranged at equal intervals along the first or second direction, or they can be arranged at non-equal intervals. The size, spacing, and position of each protective adhesive structure 70 can be adjusted according to the support strength requirements. For example, larger or denser protective adhesive structures 70 can be set in the edge area of ​​the battery cell to improve support performance, while smaller or less dense protective adhesive structures 70 can be set in the central area to reduce costs.

[0050] In some alternative embodiments, the top view shape of each protective adhesive structure 70 may be rectangular, circular, elliptical, or other irregular shapes. The three-dimensional shape of each protective adhesive structure 70 may be a semicircle, cuboid, frustum, cone, prism, frustum, or other irregular shapes.

[0051] In some alternative implementations, such as Figure 2 and Figure 3As shown, the back-contact solar cell further includes: a first electrode 50 located on the surface of the first semiconductor layer 20, the first electrode 50 including intersecting first sub-gate lines 52 and first main gate lines 51. The first main gate line 51 extends along a second direction, and the first sub-gate line 52 extends along a first direction, the first direction intersecting the second direction; each first main gate line 51 intersects with multiple parallel first sub-gate lines 52.

[0052] In specific implementation, each first semiconductor layer 20 is provided with a first main gate line 51 and a plurality of parallel first sub-gate lines 52, wherein the first main gate line 51 and the plurality of first sub-gate lines 52 on each first semiconductor layer 20 intersect.

[0053] In some alternative embodiments, the protective adhesive structure 70 is located on the side of the first sub-gate line 52 and / or on the side of the first main gate line 51; the thickness of the protective adhesive structure 70 is greater than the thickness of the first electrode 50.

[0054] In specific implementations, in some examples, the protective adhesive structure 70 is located on the surface of the first semiconductor layer 20 exposed on both sides of the first sub-gate line 52; in other examples, the protective adhesive structure 70 is located on the surface of the first semiconductor layer 20 exposed on both sides of the first main gate line 51. In still other examples, part of the protective adhesive structure 70 is located on the surface of the first semiconductor layer 20 exposed on the side of the first sub-gate line 52, and another part of the protective adhesive structure 70 is located on the surface of the first semiconductor layer 20 exposed on the side of the first main gate line 51.

[0055] In this embodiment, the protective adhesive structure 70 of the back-contact solar cell is located on the side of the first sub-grid line 52 and / or on the side of the first main grid line 51, which can better protect the first electrode 50 and prevent the first electrode 50 from being scratched. The thickness of the protective adhesive structure 70 is greater than the thickness of the first electrode 50, so that when the cells are stacked, the protective adhesive structure 70 on the back side contacts the adjacent cells, so that the first electrode 50 does not directly contact the adjacent cells but maintains a gap, which can effectively prevent the first electrode 50 from being damaged.

[0056] In some alternative embodiments, the protective adhesive structure 70 is continuously distributed along the extension direction of the first main grid line 51.

[0057] In some alternative embodiments, the protective adhesive structure 70 is continuously distributed along the extension direction of the first sub-grid line 52.

[0058] In practice, the protective adhesive structure 70 is continuously distributed, which can increase the support area of ​​the protective adhesive structure 70 and improve its support and protection performance.

[0059] In some alternative embodiments, the protective adhesive structure 70 is discontinuously distributed along the extension direction of the first main grid line 51.

[0060] In some alternative embodiments, the protective adhesive structure 70 is discontinuously distributed along the extension direction of the first sub-gate line 52.

[0061] In practice, the protective adhesive is subject to significant thermal expansion and contraction after printing and curing, resulting in surface stress. If it is continuously laid in a long strip along the same direction, this stress will accumulate along the laying direction, potentially causing further warping of the silicon wafer. Therefore, the protective adhesive structure 70 adopts a discontinuous distribution design, meaning that the protective adhesive structure 70 is divided into multiple segments along its extension direction, with gaps between adjacent segments. In this way, the stress generated during curing is divided within each segment and is no longer continuously transmitted along the entire path, which can correspondingly reduce the warping of the substrate layer 10. It should be noted that the number of segments, the length of each segment, and the spacing between adjacent segments of the protective adhesive structure 70 can be set according to the size of the solar cell, the shrinkage rate of the adhesive, and the required number of support points; this embodiment does not limit these factors.

[0062] In some alternative implementations, such as Figure 2 As shown, the protective adhesive structure 70 is disposed on the surface of the first semiconductor layer 20 on both sides of the extension direction (i.e., the first direction) of the first sub-gate line 52.

[0063] In some alternative implementations, such as Figure 3 As shown, a first pad 511 is provided at the intersection of the first main gate line 51 and a portion of the first sub-gate line 52. A protective adhesive structure 70 is provided on the surface of the first semiconductor layer 20 between adjacent first pads 511 and is located on both sides of the extension direction (i.e., the second direction) of the first main gate line 51.

[0064] The back-contact solar cell provided in this embodiment does not perform welding functions in the area between adjacent first pads 511 and on both sides of the first main grid line 51, and has a large area available for adhesive application. Setting a protective adhesive structure 70 in this area can obtain a large support area, while avoiding the location of the first pads 511, which can improve the support and protection performance of the protective adhesive, thereby improving the reliability of the back-contact solar cell.

[0065] In some alternative embodiments, the protective adhesive structure 70 is discontinuously or continuously distributed along the extension direction of the first main gate line 51 between adjacent first pads 511.

[0066] In some alternative embodiments, the protective adhesive structure 70 has a first spacing between it and the adjacent first main gate line 51; a preset solder ribbon area is provided on the surface of the first semiconductor layer 20 exposed between the protective adhesive structure 70 and the adjacent first main gate line 51.

[0067] In specific implementation, the preset solder ribbon area refers to a portion of the width of the area located on both sides of the adjacent first main gate line 51. The first spacing is greater than the width of the preset solder ribbon area, which can avoid the problem that the protective adhesive structure 70 is too high when setting the solder ribbon, causing the solder ribbon to be unable to contact the first pad. Therefore, by setting the preset solder ribbon area on the surface of the first semiconductor layer 20 between the protective adhesive structure 70 and the adjacent first main gate line 51 with the first spacing, the solder ribbon can be set in the preset solder ribbon area, that is, the solder ribbon is set on the side of the protective adhesive structure 70, which can better contact the first pad 511, thereby not affecting the interconnection lines on the back of the battery.

[0068] In this embodiment, the protective adhesive structure 70 of the back-contact solar cell is located on both sides of the extension direction of the first main grid line 51. A pre-defined solder ribbon area is provided between the protective adhesive structure 70 and the adjacent first main grid line 51. This allows the protective adhesive structure 70 to be misaligned with the pre-defined solder ribbon area, thereby improving the support and protection of adjacent cells without affecting the interconnection lines on the back of the cell, preventing damage to the cell surface, and improving the reliability of the back-contact solar cell. Furthermore, when the protective adhesive structure 70 is discontinuously distributed along the extension direction of the first main grid line 51, the stress generated by thermal expansion and contraction during the curing process is divided into multiple segments, reducing the continuous accumulation of stress on the cell. This also reduces the amount and volume of protective adhesive used, thereby lowering costs. Conversely, when the protective adhesive structure 70 is continuously distributed along the extension direction of the first main grid line 51, the support area of ​​the protective adhesive structure 70 can be increased, improving both support and protection performance.

[0069] In some alternative implementations, such as Figure 4 As shown, the protective adhesive structure 70 covers the sides and surface of the first sub-gate line 52. That is, the protective adhesive structure 70 is provided on both sides of the extension direction (i.e., the first direction) of the first sub-gate line 52, and on the side surface of the first sub-gate line 52 facing away from the substrate layer 10.

[0070] In some alternative implementations, such as Figure 2 and Figure 3 As shown, the back-contact solar cell further includes a second electrode 60 located on the surface of the second semiconductor layer 30. The second electrode 60 includes a second sub-gate line 62 and a second main gate line 61; the first main gate line 51 and the second main gate line 61 are alternately arranged along a first direction and both extend along a second direction; the first sub-gate line 52 and the second sub-gate line 62 are alternately arranged along the second direction and both extend along the first direction; the first direction and the second direction intersect. Each second main gate line 61 intersects with multiple parallel second sub-gate lines 62.

[0071] In specific implementation, each second semiconductor layer 30 is provided with a second main gate line 61 and a plurality of parallel second sub-gate lines 62, wherein the second main gate line 61 and the plurality of second sub-gate lines 62 on each second semiconductor layer 30 intersect.

[0072] It should be noted that the first direction is the extension direction of the first sub-gate line 52 / the second sub-gate line 62, and the second direction is the extension direction of the first main gate line 51 / the second main gate line 61. The two can be perpendicular to each other or intersect at a certain angle. In this embodiment, the specific angle between the first direction and the second direction is not limited.

[0073] In some alternative implementations, such as Figure 5A and Figure 6A As shown, the back-contact solar cell also includes: an insulating adhesive structure 80, which at least partially covers the first sub-grid lines 52.

[0074] In some alternative implementations, such as Figure 5A and Figure 6A As shown, the insulating adhesive structure 80 also covers part of the second subgrid line 62.

[0075] In some alternative embodiments, the thickness of the protective adhesive structure 70 is greater than the thickness of the insulating adhesive structure 80; the thickness of the insulating adhesive structure 80 is greater than the thickness of the first subgrid line 52.

[0076] In this embodiment, the back-contact solar cell has an insulating adhesive structure 80 that at least partially covers the first sub-grid line 52. This electrically isolates the first sub-grid line 52 from the second semiconductor layer 30, preventing short circuits caused by the solder ribbons on the surface of the second semiconductor layer 30 contacting the first sub-grid line 52. This solves the problem of short circuits caused by solder ribbons lapping onto electrodes of different polarities during module welding, thus improving the electrical connection reliability of the back-contact solar cell. The protective adhesive structure 70 is thicker than the insulating adhesive structure 80, and the protective adhesive structure 70 is still a structure with a higher height on the back side. When the cells are stacked, the protective adhesive structure 70 serves as a support and protection structure between adjacent cells, simultaneously protecting the first electrode 50 and the insulating adhesive structure 80 from damage.

[0077] In some alternative implementations, such as Figures 5A to 5C ,as well as Figures 6A to 6C As shown, the protective adhesive structure 70 is located at least on both sides of the extension direction of the first sub-grid line 52.

[0078] In some alternative implementations, such as Figure 5A As shown, the protective adhesive structure 70 is located on both sides of the extending direction of the first sub-grid line 52. In some alternative embodiments, such as Figure 6AAs shown, the protective adhesive structure 70 is located on both sides of the extension direction of the first sub-gate line 52 and covers the side surface of the first sub-gate line 52 facing away from the substrate layer 10, that is, the protective adhesive structure 70 covers the top surface and side surface of the first sub-gate line 52.

[0079] In some alternative implementations, such as Figure 5B and Figure 5C ,as well as Figure 6B and Figure 6C As shown, the protective adhesive structure 70 is distributed intermittently or continuously along the extension direction of the first sub-grid line 52.

[0080] In some alternative embodiments, the insulating adhesive structure 80 at least covers the end of the first sub-grid line 52 away from the first main grid line 51.

[0081] In specific implementation, the insulating adhesive structure 80 covers at least one end of the first sub-grid line 52 away from the first main grid line 51, that is, the insulating adhesive structure 80 covers at least one end of the first sub-grid line 52 close to the adjacent second main grid line 61.

[0082] In this embodiment, the protective adhesive structure 70 of the back-contact solar cell is located at least on both sides of the extension direction of the first sub-grid line 52. This allows the protective adhesive structure 70 to be evenly distributed across various positions on the back surface, improving the stress uniformity of the protective adhesive structure 70. Simultaneously, the arrangement of the protective adhesive structure 70 along the extension direction of the first sub-grid line 52 better protects the first sub-grid line 52, preventing damage and improving the protection accuracy of the protective adhesive structure 70. Furthermore, when the protective adhesive structure 70 is discontinuously distributed along the extension direction of the first sub-grid line 52, the stress generated during the curing process due to thermal expansion and contraction is divided into multiple segments, reducing the continuous accumulation of stress on the solar cell. This also reduces the amount and volume of protective adhesive used, thereby lowering costs. Conversely, when the protective adhesive structure 70 is continuously distributed along the extension direction of the first sub-grid line 52, the supporting area of ​​the protective adhesive structure 70 is increased, improving both support and protection performance. In addition, the insulating adhesive structure 80 covers the end of the first sub-grid line 52 away from the first main grid line 51, so that the end of the first sub-grid line 52 that is closer to the electrode of opposite polarity is covered, avoiding the problem of short circuit caused by the solder ribbon overlapping the electrodes of different polarities during component welding, and improving the electrical connection reliability of the back contact solar cell.

[0083] In some alternative embodiments, each first main gate line 51 connects to a plurality of first secondary gate lines 52 to form a first gate line group; the plurality of first gate line groups are arranged alternately along a first direction; the first gate line group corresponding to each first main gate line 51 does not intersect with the second main gate lines 61 on both sides. The insulating adhesive structure 80 located on the surface of the first semiconductor layer 20 covers part of the first secondary gate line 52 near one end of the adjacent second main gate line 61.

[0084] In some alternative embodiments, each second main gate line 61 connects to a plurality of second sub-gate lines 62 to form a second gate line group; the plurality of second gate line groups are arranged alternately along a first direction; the second gate line group corresponding to each second main gate line 61 does not intersect with the first main gate lines 51 on both sides. The insulating adhesive structure 80 located on the surface of the second semiconductor layer 30 covers part of the second sub-gate line 62 close to one end of the adjacent first main gate line 51.

[0085] In some alternative implementations, such as Figure 5A As shown, the protective adhesive structure 70 covers the sides and surface of the first subgrid line 52.

[0086] In some alternative implementations, such as Figure 5A As shown, the insulating adhesive structure 80 is located on both sides of the extension direction of the first sub-grid line 52 and covers the side of the protective adhesive structure 70 away from the first sub-grid line 52. That is, the insulating adhesive structure 80 is located on both sides of the extension direction of the first sub-grid line 52 and is located on the outer side of the protective adhesive structure 70.

[0087] In some alternative implementations, such as Figure 5B As shown, the protective adhesive structure 70 is continuously distributed along the extension direction of the first sub-grid line 52.

[0088] In some alternative implementations, such as Figure 5C As shown, the protective adhesive structure 70 is discontinuously distributed along the extension direction of the first sub-grid line 52.

[0089] In this embodiment, the back-contact solar cell has a protective adhesive structure 70 covering the first sub-grid line 52, and an insulating adhesive structure 80 covering the outer surface of the protective adhesive structure 70. The insulating adhesive structure 80 can increase the support area of ​​the protective adhesive structure 70, prevent the protective adhesive structure 70 from shifting and deforming, improve the stability and support of the protective adhesive structure 70, and thus improve the support and protection performance of the protective adhesive structure 70.

[0090] In some alternative implementations, such as Figure 6A As shown, the insulating adhesive structure 80 covers the sides and surface of the first subgrid line 52.

[0091] In some alternative implementations, such as Figure 6A As shown, the protective adhesive structure 70 is located on both sides of the extension direction of the first sub-grid line 52 and covers the side of the insulating adhesive structure 80 away from the first sub-grid line 52. That is, the protective adhesive structure 70 is located on both sides of the extension direction of the first sub-grid line 52 and is located on the outer side of the insulating adhesive structure 80.

[0092] In some alternative implementations, such as Figure 6BAs shown, the protective adhesive structure 70 is continuously distributed along the extension direction of the first sub-grid line 52.

[0093] In some alternative implementations, such as Figure 6C As shown, the protective adhesive structure 70 is discontinuously distributed along the extension direction of the first sub-grid line 52.

[0094] In this embodiment, the back-contact solar cell has an insulating adhesive structure 80 covering part of the side and surface of the first sub-grid line 52. This provides a relatively good insulating adhesive structure 80 between the first sub-grid line 52 and the outside, solving the problem of leakage risk caused by insufficient insulation and density of the protective adhesive structure when it directly contacts the first sub-grid line 52. This further improves the electrical connection reliability of the back-contact solar cell. The protective adhesive structure 70 is disposed on the outer side of the insulating adhesive structure 80 and serves as a spacer and support, protecting both the first electrode 50 and the insulating adhesive structure 80 from damage.

[0095] In some alternative implementations, such as Figure 7 As shown, the back-contact solar cell further includes an auxiliary protective adhesive structure 71, located on the side surface of the second semiconductor layer 30 facing away from the substrate layer 10. The auxiliary protective adhesive structure 71 is located on the side of the second sub-grid line 62 and / or on the side of the second main grid line 61; the thickness of the auxiliary protective adhesive structure 71 is greater than the thickness of the second electrode 60.

[0096] The back-contact solar cell provided in this embodiment, by providing an auxiliary protective adhesive structure 71 on the surface of the second semiconductor layer 30, can make the distribution of support protection points on the backlight surface more dispersed, further improving the reliability of the back-contact solar cell; the thickness of the auxiliary protective adhesive structure 71 is greater than the thickness of the second electrode 60, so that when the cells are stacked, the auxiliary protective adhesive structure 71 contacts the adjacent cells, so that the second electrode 60 does not directly contact the adjacent cells but maintains a gap, which can effectively prevent the second electrode 60 from being damaged.

[0097] In some alternative embodiments, the auxiliary protective adhesive structure 71 is a raised structure, and the vertical cross-section of the auxiliary protective adhesive structure 71 can be rectangular, conical, semi-circular, etc.

[0098] In some alternative embodiments, the auxiliary protective adhesive structure 71, extending in a continuous strip along a first or second direction, can increase the support area. Specifically, the top view shape of the auxiliary protective adhesive structure 71 can be a straight or curved strip.

[0099] In some optional embodiments, each second semiconductor layer 30 is provided with a plurality of auxiliary protective adhesive structures 71, which are spaced apart on the surface of the second semiconductor layer 30. The top view shape of each auxiliary protective adhesive structure 71 can be rectangular, circular, elliptical, or other irregular shape. The three-dimensional shape of each auxiliary protective adhesive structure 71 can be a semicircle, cuboid, frustum, cone, prism, frustum, or other irregular shape.

[0100] In some alternative implementations, the thickness of the auxiliary protective adhesive structure 71 is greater than the thickness of the protective adhesive structure 70.

[0101] In some alternative embodiments, the upper surface of the auxiliary protective adhesive structure 71 is flush with the upper surface of the protective adhesive structure 70, and together they can serve as a support and protective structure.

[0102] In some alternative embodiments, the width of the auxiliary protective adhesive structure 71 is smaller than the width of the protective adhesive structure 70; and / or, the length of the auxiliary protective adhesive structure 71 is smaller than the length of the protective adhesive structure 70; and / or, the number of auxiliary protective adhesive structures 71 is smaller than the number of protective adhesive structures 70. This can reduce the amount of protective adhesive material used to form the auxiliary protective adhesive structure 71, thereby reducing costs.

[0103] In some alternative implementations, such as Figure 8 As shown, the auxiliary protective adhesive structure 71 is located on the side of the second sub-grid line 62.

[0104] In some alternative embodiments, the auxiliary protective adhesive structure 71 is distributed continuously or discontinuously along the extension direction of the second sub-grid line 62.

[0105] In some alternative implementations, such as Figure 9 As shown, the auxiliary protective adhesive structure 71 is located on the side of the second main grid line 61.

[0106] In some alternative implementations, such as Figure 9 As shown, a second pad 611 is provided at the intersection of the second main gate line 61 and a portion of the second sub-gate line 62. An auxiliary protective adhesive structure 71 is provided on the surface of the second semiconductor layer 30 between adjacent second pads 611, and is located on both sides of the extension direction (i.e., the second direction) of the second main gate line 61.

[0107] The back-contact solar cell provided in this embodiment does not perform welding functions in the area between adjacent second pads 611 and on both sides of the second main grid line 61, and has a large area available for adhesive application. Setting an auxiliary protective adhesive structure 71 in this area can obtain a large support area. At the same time, avoiding the location of the second pads 611 can improve the support and protection performance of the auxiliary protective adhesive structure 71, thereby improving the reliability of the back-contact solar cell.

[0108] In some alternative implementations, the auxiliary protective adhesive structure 71 is discontinuously or continuously distributed along the extension direction of the second main gate line 61 between adjacent second pads 611.

[0109] In some alternative implementations, such as Figure 10 As shown, the back-contact solar cell also includes a plurality of front protective adhesive bumps 90, located on the light-receiving surface of the substrate 10, and corresponding to the protective adhesive structure 70. The projection of the protective adhesive structure 70 on the substrate 10 covers the projection of the front protective adhesive bumps 90 on the substrate 10.

[0110] The back-contact solar cell provided in this embodiment obtains front protective adhesive protrusions 90 at positions corresponding to the protective adhesive structure 70 on the light-receiving surface. This allows the stacked solar cells to also have support points on the light-receiving side, further improving the scratch phenomenon and enhancing the reliability of the back-contact solar cell. By having the front protective adhesive protrusions 90 correspond to the protective adhesive structure 70 and their projections overlap, the area of ​​the light-receiving surface that is blocked can be limited to the vicinity of the projection range of the protective adhesive structure 70, which can significantly reduce the blocking area.

[0111] In some alternative embodiments, the protective adhesive protrusions 90 on the front side of the light-receiving surface are provided in a one-to-one correspondence with the protective adhesive structure 70 on the back side.

[0112] In some alternative implementations, the number of protective adhesive bumps 90 on the front side of the light-receiving surface is less than the number of protective adhesive structures 70 on the back side.

[0113] In some alternative implementations, the size of the protective adhesive bumps 90 on the front side of the light-receiving surface is smaller than the size of the protective adhesive structure 70 on the back side.

[0114] In some alternative implementations, the first semiconductor layer 20 is a P-type semiconductor layer; the second semiconductor layer 30 is an N-type semiconductor layer.

[0115] In practice, during the battery fabrication process, a full-surface P-type semiconductor layer is typically formed first, followed by etching out a predetermined region of the N-type semiconductor layer (i.e., the second region 102). To ensure complete etching, the second region 102 is lower than the first region 101 where the P-type semiconductor layer is located. Then, the N-type semiconductor layer is formed in the second region 102. Since the height difference between the P-type and N-type semiconductor layers is small, much smaller than the height difference between the first region 101 and the second region 102, the surface of the P-type semiconductor layer ultimately protrudes above the surface of the N-type semiconductor layer; that is, the surface of the P-type semiconductor layer facing away from the first region 101 is higher than the surface of the N-type semiconductor layer facing away from the second region 102. Finally, an isolation groove 40 is formed between the P-type and N-type semiconductor layers. To achieve electrical isolation, the isolation groove 40 needs to be lower than the first region 101 and the second region 102. Ultimately, different shapes will naturally form on the backlight surface, with the P-type semiconductor layer having the highest height, the N-type semiconductor layer having the next highest height, and the adjacent P-type semiconductor layers and the isolation groove 40 used to separate the different polarities having the lowest height.

[0116] In the back-contact solar cell provided in this embodiment, the height of the first region 101 corresponding to the P-type semiconductor layer is greater than the height of the second region 102 corresponding to the N-type semiconductor layer, and the surface of the P-type semiconductor layer protrudes from the surface of the N-type semiconductor layer. By setting a protective adhesive structure 70 on the surface of the P-type semiconductor layer, the protective adhesive structure 70 is located at the most protruding and easily scratched position on the backlight surface. This better protects the P-type semiconductor layer when the cells are stacked. It can also reduce the height and volume of the protective adhesive structure 70, thereby reducing the manufacturing and storage costs of the cell. Thus, by setting the protective adhesive structure 70 in a part of the backlight surface, the effect of avoiding scratches between cells can be achieved, improving the reliability of the back-contact solar cell.

[0117] In some alternative implementations, the first semiconductor layer 20 is a first doped polysilicon layer, and the second semiconductor layer 30 is a second doped polysilicon layer.

[0118] In some alternative embodiments, the first doped polysilicon layer is a P-type doped polysilicon layer and the P-type semiconductor layer is a P-type doped polysilicon layer; the second doped polysilicon layer is an N-type doped polysilicon layer and the N-type semiconductor layer is an N-type doped polysilicon layer.

[0119] In some alternative embodiments, the back-contact solar cell further includes: a first tunneling oxide layer 21 located between the first semiconductor layer 20 and a first region 101 of the substrate layer 10; a second tunneling oxide layer 31 located between the second semiconductor layer 30 and a second region 102 of the substrate layer 10; an isolation groove 40 located between adjacent first semiconductor layers 20 and second semiconductor layers 30 and extending into the substrate layer 10; the isolation groove 40 is also located between adjacent first tunneling oxide layers 21 and second tunneling oxide layers 31.

[0120] In a specific implementation, the isolation groove 40 separates the adjacent first semiconductor layer 20 and second semiconductor layer 30, and also separates the adjacent first tunneling oxide layer 21 and second tunneling oxide layer 31.

[0121] In this embodiment of the back-contact solar cell, the first tunneling oxide layer 21 is located between the first semiconductor layer 20 and the substrate layer 10, and the second tunneling oxide layer 31 is located between the second semiconductor layer 30 and the substrate layer 10. This can reduce the carrier transport barrier and improve the carrier transport efficiency. The isolation groove 40 extends into the substrate layer 10 and simultaneously isolates the adjacent first semiconductor layer 20 and second semiconductor layer 30, as well as the adjacent first tunneling oxide layer 21 and second tunneling oxide layer 31, so that the two polarity regions are separated from each other in the lateral direction. This can prevent the first semiconductor layer 20 and the second semiconductor layer 30 from conducting. Furthermore, the isolation groove 40 is formed on the back light surface at a height lower than the first region 101 and the second region 102, thereby forming a height difference where the first region 101 is higher than the second region 102 and the second region 102 is higher than the isolation groove 40. This allows the protective adhesive structure 70 on the surface of the highest first semiconductor layer 20 to protect the entire back light surface from damage, improving the reliability of the back-contact solar cell.

[0122] In some alternative embodiments, the protective adhesive structure 70, the auxiliary protective adhesive structure 71, the front protective adhesive bump 90, and the insulating adhesive structure 80 can all be formed by printing and curing after the first electrode and the second electrode have been printed and sintered.

[0123] It should be noted that the specific printing and curing processes, the printed patterns, and the curing conditions can be selected according to the characteristics of the adhesive and the production line conditions. This embodiment does not limit these aspects.

[0124] This disclosure also provides a method for preparing a back-contact solar cell, including steps S101 to S103.

[0125] Step S101: Provide a substrate layer, the substrate layer including a light-receiving surface and a backlight surface disposed opposite to each other; the backlight surface of the substrate layer includes a first region and a second region arranged alternately along a first direction, the height of the first region being greater than the height of the second region.

[0126] Step S102: A first semiconductor layer is formed on the surface of the first region, and a second semiconductor layer is formed on the surface of the second region; the first semiconductor layer and the second semiconductor layer are alternately spaced along a first direction on the backlight side of the substrate layer; the surface of the first semiconductor layer protrudes from the surface of the second semiconductor layer.

[0127] Step S103: A protective adhesive structure is formed, which is located on the side surface of the first semiconductor layer facing away from the substrate layer.

[0128] In some alternative embodiments, prior to forming the protective adhesive structure, the method further includes: forming a first electrode on the surface of the first semiconductor layer, and forming a second electrode on the surface of the first semiconductor layer. The first electrode includes intersecting first sub-gate lines and a first main gate line, and the second electrode includes intersecting second sub-gate lines and a second main gate line.

[0129] In some alternative embodiments, the protective adhesive structure is formed on the side of the first sub-grid line and / or on the side of the first main grid line.

[0130] In some alternative embodiments, the preparation method further includes: forming an insulating adhesive structure that at least partially covers the first sub-grid line.

[0131] In some alternative embodiments, the insulating adhesive structure is formed after the protective adhesive structure. The protective adhesive structure covers the sides and surfaces of the first subgrid line; the insulating adhesive structure is located on both sides of the first subgrid line in the direction of extension and covers the sides of the protective adhesive structure away from the first subgrid line (i.e., covers the outer side of the protective adhesive structure).

[0132] In some alternative embodiments, the insulating adhesive structure is formed prior to the protective adhesive structure. The insulating adhesive structure covers the sides and surfaces of a portion of the first subgrid line; the protective adhesive structure is located on both sides of the first subgrid line in its extension direction and covers the sides of the insulating adhesive structure away from the first subgrid line (i.e., covers the outer side of the insulating adhesive structure).

[0133] This disclosure also provides a back-contact solar cell module, including the aforementioned back-contact solar cell.

[0134] In the description of this specification, the references to terms such as "this embodiment," "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0135] The above description does not provide detailed explanations of the technical aspects of each layer's patterning, etching, etc. However, those skilled in the art should understand that various technical means can be used to form layers and regions of the desired shape. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination.

[0136] The above description is merely a preferred embodiment and the technical principles employed in this disclosure. Those skilled in the art will understand that this disclosure is not limited to the specific embodiments described above, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of this disclosure. Therefore, although this disclosure has been described in detail through the above embodiments, it is not limited to the above embodiments. Many other equivalent embodiments may be included without departing from the concept of this disclosure, and the scope of protection of this disclosure is determined by the scope of the appended claims.

Claims

1. A back-contact solar cell, characterized in that, include: The substrate layer includes a light-receiving surface and a back-lighting surface disposed opposite to each other; the back-lighting surface of the substrate layer includes a first region and a second region arranged alternately along a first direction, wherein the height of the first region is greater than the height of the second region. A first semiconductor layer and a second semiconductor layer are alternately disposed on one side of the backlight surface of the substrate layer along a first direction; the first semiconductor layer is located on the surface of the first region, and the second semiconductor layer is located on the surface of the second region; the surface of the first semiconductor layer protrudes from the surface of the second semiconductor layer. A first electrode is located on the surface of the first semiconductor layer; the first electrode includes intersecting first sub-gate lines and first main gate lines, wherein the first main gate lines extend along a second direction, the first sub-gate lines extend along a first direction, and the first direction intersects with the second direction; each first main gate line intersects with multiple parallel first sub-gate lines; A protective adhesive structure is located on the side surface of the first semiconductor layer facing away from the substrate layer; the protective adhesive structure is located on the side of the first sub-gate line and / or on the side of the first main gate line; the thickness of the protective adhesive structure is greater than the thickness of the first electrode.

2. The back-contact solar cell according to claim 1, characterized in that, A first pad is provided at the intersection of the first main gate line and part of the first sub-gate line; The protective adhesive structure is disposed on the surface of the first semiconductor layer between adjacent first pads and located on both sides of the extension direction of the first main gate line.

3. The back-contact solar cell according to claim 2, characterized in that, Between adjacent first pads, the protective adhesive structure is distributed intermittently or continuously along the extension direction of the first main grid line; The protective adhesive structure has a first spacing with the adjacent first main gate line; a preset solder ribbon area is provided on the surface of the first semiconductor layer exposed between the protective adhesive structure and the adjacent first main gate line.

4. The back-contact solar cell according to claim 1, characterized in that, The back-contact solar cell also includes: An insulating adhesive structure that at least partially covers the first sub-grid line; The thickness of the protective adhesive structure is greater than the thickness of the insulating adhesive structure; the thickness of the insulating adhesive structure is greater than the thickness of the first sub-grid line.

5. The back-contact solar cell according to claim 4, characterized in that, The protective adhesive structure is located at least on both sides of the extension direction of the first sub-gate line; The protective adhesive structure is distributed intermittently or continuously along the extension direction of the first sub-gate line. The insulating adhesive structure at least covers the end of the first sub-grid line that is away from the first main grid line.

6. The back-contact solar cell according to claim 5, characterized in that, The protective adhesive structure covers the sides and surface of the first sub-grid line; The insulating adhesive structure is located on both sides of the extension direction of the first sub-gate line and covers the side of the protective adhesive structure away from the first sub-gate line.

7. The back-contact solar cell according to claim 5, characterized in that, The insulating adhesive structure covers the sides and surfaces of the first sub-grid line; The protective adhesive structure is located on both sides of the extension direction of the first sub-gate line and covers the side of the insulating adhesive structure away from the first sub-gate line.

8. The back-contact solar cell according to claim 1, characterized in that, The back-contact solar cell also includes: The second electrode is located on the surface of the second semiconductor layer. The second electrode includes a second sub-gate line and a second main gate line. The first main gate line and the second main gate line are alternately spaced along a first direction and both extend along a second direction. The first sub-gate line and the second main gate line are alternately spaced along the second direction and both extend along the first direction. The first direction and the second direction intersect. The back-contact solar cell also includes: An auxiliary protective adhesive structure is located on the side surface of the second semiconductor layer facing away from the substrate layer; The auxiliary protective adhesive structure is located on the side of the second sub-gate line and / or on the side of the second main gate line; the thickness of the auxiliary protective adhesive structure is greater than the thickness of the second electrode.

9. The back-contact solar cell according to claim 1, characterized in that, The back-contact solar cell also includes: The front protective adhesive protrusions are located on the light-receiving surface of the substrate layer and are correspondingly arranged with respect to the protective adhesive structure; the projection of the protective adhesive structure on the substrate layer covers the projection of the front protective adhesive protrusions on the substrate layer.

10. The back-contact solar cell according to claim 1, characterized in that, The first semiconductor layer is a P-type semiconductor layer; the second semiconductor layer is an N-type semiconductor layer.

11. The back-contact solar cell according to claim 1, characterized in that, The first semiconductor layer is a first doped polysilicon layer, and the second semiconductor layer is a second doped polysilicon layer; The back-contact solar cell also includes: A first tunneling oxide layer is located between the first semiconductor layer and the substrate layer; The second tunneling oxide layer is located between the second semiconductor layer and the substrate layer; An isolation groove is located between adjacent first semiconductor layers and second semiconductor layers, and extends into the substrate layer; the isolation groove is also located between adjacent first tunneling oxide layers and second tunneling oxide layers. The isolation grooves separate adjacent first semiconductor layers and second semiconductor layers, and also separate adjacent first tunneling oxide layers and second tunneling oxide layers.

12. A back-contact solar cell module, characterized in that, Including the back-contact solar cell as described in any one of claims 1 to 11.

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