Back contact solar cell

Abstract

The utility model discloses a back contact solar cell, and relates to the technical field of solar cells. The back contact solar cell comprises: a silicon substrate; first doped regions and second doped regions are alternately arranged on the back surface of the silicon substrate, and the first doped regions and the second doped regions are staggered in the thickness direction of the silicon substrate; the projections of the adjacent first doped region and second doped region on a plane parallel to the cross section of the silicon substrate are partially overlapped or the edges of the first doped region and second doped region are adjacent; the doping type of the first doped region is opposite to the doping type of the second doped region. According to the structure provided by the utility model, the first doped regions and the second doped regions are alternately arranged on the back surface of the silicon substrate and staggered in the thickness direction of the silicon substrate, so that the first doped regions and the second doped regions are not adjacent to each other, and the available area of the back surface of the back contact solar cell is effectively improved; and the photoelectric conversion efficiency is relatively high.

Description

Technical Field

[0001] The utility model relates to the technical field of solar cells, in particular to a back contact solar cell. Background Art

[0002] The P-type doped structure and N-type doped structure of the interdigitated back contact (IBC) solar cell are arranged alternately on the back of the cell, so that the light-receiving area of ​​the front of the cell can reach 100%. However, in the existing IBC, in order to prevent leakage between the P-type doped structure and the N-type doped structure, a certain interval is often set between adjacent P-type doped structures and N-type doped structures. Such a layout will cause the effective area of ​​the IBC cell to be smaller than the theoretical area, resulting in lower cell efficiency. Utility Model Content

[0003] In view of this, the utility model provides a back contact solar cell, which solves the problem of low cell efficiency caused by setting a gap between the first doping region and the second doping region by staggered arrangement of the first doping region and the second doping region.

[0004] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0005] The utility model provides a back contact solar cell, comprising:

[0006] Silicon substrate;

[0007] A first doped region and a second doped region are alternately arranged on the back of the silicon substrate, wherein the first doped region and the second doped region are staggered in the thickness direction of the silicon substrate;

[0008] The projections of the adjacent first doped regions and the adjacent second doped regions on a plane parallel to the cross section of the silicon substrate partially overlap or have edges that are adjacent;

[0009] The doping type of the first doping region is opposite to the doping type of the second doping region.

[0010] Optionally, the back contact solar cell further comprises: a plurality of grooves spaced apart on the back side of the silicon substrate, wherein an angle between a side surface of the groove and a bottom surface of the groove is less than or equal to 90°;

[0011] The first doped region is disposed on a platform adjacent to the groove, and the second doped region is disposed in the groove.

[0012] Optionally, the angle between the side surface of the groove and the bottom surface of the groove is not less than 70°;

[0013] and / or,

[0014] The depth of the groove is 3 μm to 10 μm;

[0015] and / or,

[0016] The bottom width of the groove is 500 μm to 1000 μm;

[0017] and / or,

[0018] The width of the platform adjacent to the groove is 400 μm to 600 μm

[0019] Optionally, the first doped region includes: a first doped layer;

[0020] The second doped region includes: a second doped layer.

[0021] Optionally, the first doped region further comprises: a first tunneling oxide layer or a first intrinsic amorphous silicon layer disposed between the first doped layer and the silicon substrate;

[0022] The second doped region further includes: a second tunneling oxide layer or a second intrinsic amorphous silicon layer disposed between the second doped layer and the silicon substrate.

[0023] Optionally, when the first doped region includes the first tunneling oxide layer, and the second doped region includes the second tunneling oxide layer,

[0024] The thickness of the first tunnel oxide layer and the second tunnel oxide layer is 0.5 nm-3.0 nm;

[0025] The thickness of the first doping layer and the second doping layer is 50nm-300nm.

[0026] Optionally, when the first doped region includes the first intrinsic amorphous silicon layer, and the second doped region includes the second intrinsic amorphous silicon layer,

[0027] The thickness of the first intrinsic amorphous silicon layer and the second intrinsic amorphous silicon layer is 5nm-10nm;

[0028] The thickness of the first doping layer and the second doping layer is 10nm-30nm.

[0029] Optionally, the back contact solar

[0030] The battery further includes: a passivation anti-reflection layer arranged on the first doped region and the second doped region.

[0031] Optionally, the back-contact solar cell further comprises: a first electrode and a second electrode;

[0032] The first electrode penetrates the passivation anti-reflection layer and is electrically connected to the first doped region;

[0033] The second electrode penetrates the passivation anti-reflection layer and is electrically connected to the second doped region.

[0034] Optionally, the front side of the silicon substrate has a suede structure.

[0035] The technical solution of the first aspect of the above utility model has the following advantages or beneficial effects:

[0036] The back-contact solar cell provided by the utility model is provided with a first doped region and a second doped region which are alternately arranged and staggered in the thickness direction of the silicon substrate on the back side of a silicon substrate, that is, the first doped region and the second doped region are staggered in the thickness direction so that the first doped region and the second doped region are not in contact with each other, so that there is no need to set a horizontal interval between the first doped region and the second doped region, and the projections of adjacent first doped regions and second doped regions on the plane where the cross section of the silicon substrate is located partially overlap or the edges are adjacent, which effectively increases the available area of ​​the back side of the back-contact solar cell, greatly improves the fill factor and the short-circuit current of the back-contact solar cell, and makes the back-contact solar cell have a higher photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of the structure of a back contact solar cell according to the prior art;

[0038] Figure 2 is a schematic structural diagram of a back-contact solar cell according to an embodiment of the utility model;

[0039] Figure 3 A schematic diagram showing the angle between the side surface of the groove and the bottom surface of the groove provided in an embodiment of the utility model;

[0040] Figure 4 A schematic diagram showing a first structure of a first doped region and a second doped region provided by an embodiment of the utility model is shown;

[0041] Figure 5 A second structural schematic diagram of the first doping region and the second doping region provided by an embodiment of the utility model is shown;

[0042] Figure 6 A third structural schematic diagram of the first doping region and the second doping region provided in an embodiment of the utility model is shown.

[0043] The reference numerals are as follows:

[0044] 10-silicon substrate; 20-first doped region; 21-first doped layer; 22-first tunneling oxide layer; 23-first intrinsic amorphous silicon layer; 30-second doped region; 31-second doped layer; 32-second tunneling oxide layer; 33-second intrinsic amorphous silicon layer; 40-groove; 41-side of the groove; 42-bottom of the groove;

[0045] 50 - first electrode; 60 - second electrode; 70 - passivation anti-reflection layer. DETAILED DESCRIPTION

[0046] like Figure 1 In the conventional back-contact solar cell shown, a certain interval is provided between the first doping region and the second doping region, so that the effective area of ​​the doping layer is smaller than the area of ​​the silicon substrate, resulting in low cell efficiency.

[0047] The following is a description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0048] The back side of the silicon substrate involved in the utility model refers to the side of the back contact solar cell facing away from the sunlight when working, that is, the side of the silicon substrate away from the sunlight. The front side of the silicon substrate involved in the utility model refers to the side of the back contact solar cell facing the sunlight when working, that is, the light-receiving side of the back contact solar cell.

[0049] The upper surface of a structure in the back-contact solar cell involved in the utility model means that when the back-contact solar cell is in use, the side of the structure facing the sunlight is the upper surface, and the side facing away from the sunlight is the lower surface.

[0050] The terms “first”, “second”, etc. mentioned in the embodiments of the present invention are used to distinguish different structures or components or different positions of the same structure, and are not intended to limit the number, order, etc. of structures or components.

[0051] like Figure 2As shown, the utility model provides a back-contact solar cell, comprising: a silicon substrate 10; a first doping region 20 and a second doping region 30 are alternately arranged on the back of the silicon substrate 10, wherein the first doping region 20 and the second doping region 30 are staggered in the thickness direction of the silicon substrate 10; the projections of the adjacent first doping regions 20 and the second doping regions 30 on a plane parallel to the cross section of the silicon substrate 10 partially overlap or the edges are adjacent; the doping type of the first doping region 20 is opposite to the doping type of the second doping region 30. The edge adjacency means that there is no gap between the edge of the projection of the first doping region 20 on a plane parallel to the cross section of the silicon substrate 10 and the edge of the projection of the second doping region 30 on a plane parallel to the cross section of the silicon substrate 10.

[0052] Specifically, the first doping region 20 and the second doping region 30 are staggered in the thickness direction of the silicon substrate 10, and the first doping region 20 and the second doping region 30 are alternately arranged in the horizontal direction, and the first doping region 20 and the second doping region 30 are located at different thicknesses. Moreover, the upper surface of the first doping region 20 (i.e., the main surface where the first doping region 20 contacts the silicon substrate 10) and the lower surface of the second doping region 30 are on different horizontal planes. The first doping region 20 and the second doping region 30 are staggered in the thickness direction of the silicon substrate 10, so that the two regions are not adjacent, and there is no need to set a gap between the first doping region 20 and the second doping region 30 in the horizontal direction.

[0053] Furthermore, the back contact solar cell further comprises: a plurality of grooves 40 arranged at intervals on the back side of the silicon substrate 10. Figure 3 As shown, the angle α between the side surface 41 of the groove and the bottom surface 42 of the groove is less than or equal to 90°. The longitudinal section of the groove 40 can be displayed as a rectangle, a square or a trapezoid. The bottom surface 42 of the groove refers to the side of the groove 40 that is closest to the front of the silicon substrate 10, that is, the bottom wall of the groove 40. The depth of the above-mentioned groove 40 is generally 3μm to 10μm. For example, the depth of the groove 40 can be 3μm, 5μm, 7μm, 10μm, etc. The bottom width of the above-mentioned groove 40 is 500μm to 1000μm. For example, the bottom width of the groove 40 can be 500μm, 650μm, 800μm, 1000μm, etc. The width of the platform adjacent to the above-mentioned groove 40 can be 400μm to 600μm. For example, the width of the platform can be 400μm, 500μm, 600μm, etc.

[0054] By designing the depth of the groove 40 , the bottom width, and the width of the platform adjacent to the groove 40 , the first doped region 20 and the second doped region 30 have a better area ratio, thereby improving the photoelectric conversion efficiency.

[0055] Preferably, if Figure 3 As shown, the angle between the side surface 41 of the groove and the bottom surface 42 of the groove is not less than 70°, that is, the angle α between the side surface 41 of the groove and the bottom surface 42 of the groove can be 70°≤α≤90°. For example, the angle α between the side surface 41 of the groove and the bottom surface 42 of the groove can be 70°, 80°, 90°, etc.

[0056] By designing the angle between the side surface 41 of the groove and the bottom surface 42 of the groove to be not less than 70°, a reasonable structure is provided between the groove and the platform, and the platform is not unstable and prone to collapse due to a small angle. At the same time, the second doping region has a reasonable width.

[0057] The first doped region 20 is disposed on a platform adjacent to the groove 40 , and the second doped region 30 is disposed in the groove 40 .

[0058] When the angle between the side surface 41 of the groove and the bottom surface 42 of the groove is equal to 90°, the projected edges of the first doped region 20 and the second doped region 30 on the plane parallel to the cross section of the silicon substrate 10 are adjacent, so that the projected area of ​​the first doped region 20 and the second doped region 30 on the plane parallel to the cross section of the silicon substrate 10 is equal to the projected area of ​​the above-mentioned silicon substrate 10 on the plane; when the angle between the side surface 41 of the groove and the bottom surface 42 of the groove is less than 90°, the projections of the first doped region 20 and the second doped region 30 on the plane parallel to the cross section of the silicon substrate 10 partially overlap, so that the sum of the projected area S1 of the first doped region 20 on the plane parallel to the cross section of the silicon substrate 10 and the projected area S2 of the second doped region 30 on the plane parallel to the cross section of the silicon substrate 10 is greater than the projected area S3 of the above-mentioned silicon substrate 10 on the plane. By arranging the first doping region 20 and the second doping region 30 to be non-adjacent and S1+S2≥S3, there is no gap between the first doping region 20 and the second doping region 30. At the same time, the available area of ​​the back side of the back contact solar cell is effectively increased, and the photoelectric conversion efficiency of the IBC solar cell is greatly improved.

[0059] Furthermore, the first doping region 20 includes: a first doping layer 21 ; and the second doping region 30 includes: a second doping layer 31 .

[0060] Furthermore, the first doped region 20 may further include: a first tunneling oxide layer 22 or a first intrinsic amorphous silicon layer 23 disposed between the first doped layer 21 and the silicon substrate 10; the second doped region 30 may further include: a second tunneling oxide layer 32 or a second intrinsic amorphous silicon layer 33 disposed between the second doped layer 31 and the silicon substrate 10. The first tunneling oxide layer 22 and the second tunneling oxide layer 32 may be the same tunneling oxide layer; the first intrinsic amorphous silicon layer 23 and the second intrinsic amorphous silicon layer 33 may be the same intrinsic amorphous silicon layer.

[0061] It can be seen from the above that the first doping region 20 and the second doping region 30 include at least the following three situations:

[0062] The first one, such as Figure 4 As shown, there is only the first doping layer 21 in the first doping region 20, and there is only the second doping layer 31 in the second doping region 30. Specifically, when the first doping layer 21 is a P+ doping layer, the second doping layer 31 is an N+ doping layer; when the first doping layer 21 is an N+ doping layer, the second doping layer 31 is a P+ doping layer.

[0063] The second type, such as Figure 5 As shown, the first doping region 20 includes a first doping layer 21 and a first tunneling oxide layer 22, and the second doping region 30 includes a second doping layer 31 and a second tunneling oxide layer 32. The first tunneling oxide layer 22 is disposed below the first doping layer 21, that is, the side of the first doping layer 21 close to the silicon substrate 10; the second tunneling oxide layer 32 is disposed below the second doping layer 31, that is, the side of the second doping layer 31 close to the silicon substrate 10. Specifically, when the first doping layer 21 also includes the first tunneling oxide layer 22 and the second doping layer 31 also includes the second tunneling oxide layer 32, when the first doping layer 21 is a P-type doped polysilicon layer, the second doping layer 31 is an N-type doped polysilicon layer; when the first doping layer 21 is an N-type doped polysilicon layer, the second doping layer 31 is a P-type doped polysilicon layer.

[0064] Wherein, the first tunnel oxide layer 22 and the second tunnel oxide layer 32 may be silicon oxide layers, and the thickness thereof may be 0.5 nm-3.0 nm. For example, the thickness of the first tunnel oxide layer 22 and the second tunnel oxide layer 32 may be 0.5 nm, 1.0 nm, 2.0 nm, 3.0 nm, etc. At this time, the thickness of the first doping layer 21 and the second doping layer 31 may be 50 nm-300 nm. For example, the thickness of the first doping layer 21 and the second doping layer 31 may be 50 nm, 100 nm, 150 nm, 200 nm, 300 nm, etc.

[0065] The third type, such as Figure 6As shown, the first doping region 20 includes a first doping layer 21 and a first intrinsic amorphous silicon layer 23, and the second doping region 30 includes a second doping layer 31 and a second intrinsic amorphous silicon layer 33. The first intrinsic amorphous silicon layer 23 is disposed below the first doping layer 21, that is, the side of the first doping layer 21 close to the silicon substrate 10; the second intrinsic amorphous silicon layer 33 is disposed below the second doping layer 31, that is, the side of the second doping layer 31 close to the silicon substrate 10. Specifically, when the first doping layer 21 also includes the first intrinsic amorphous silicon layer 23 and the second doping layer 31 also includes the second intrinsic amorphous silicon layer 33, when the first doping layer 21 is a P-type doped amorphous silicon layer, the second doping layer 31 is an N-type doped amorphous silicon layer; when the first doping layer 21 is an N-type doped amorphous silicon layer, the second doping layer 31 is a P-type doped amorphous silicon layer.

[0066] The first intrinsic amorphous silicon layer 23 and the second intrinsic amorphous silicon layer 33 may be hydrogenated amorphous silicon intrinsic layers, and the thickness thereof may be 5nm-10nm; at this time, the thickness of the first doping layer 21 and the second doping layer 31 may be 10nm-30nm.

[0067] In addition, in addition to the above-mentioned doping layer and intrinsic amorphous silicon layer, the first doping region 20 and the second doping region 30 of the above-mentioned back contact solar cell may also include other functional layers such as a tunneling passivation layer, a conductive film layer, and the like.

[0068] Furthermore, if Figure 2 As shown, the back contact solar cell further includes: a passivation anti-reflection layer 70 disposed on the first doped region 20 and the second doped region 30. The passivation anti-reflection layer 70 may be composed of one or more of aluminum oxide, silicon nitride, silicon oxynitride, and silicon oxide. The passivation anti-reflection layer 70 covers the first doped layer 21 and the second doped layer 31 on the side away from the silicon substrate 10.

[0069] Furthermore, if Figure 2 As shown, the back-contact solar cell further includes: a first electrode 50 and a second electrode 60 .

[0070] The first electrode 50 penetrates the passivation anti-reflection layer 70 and is electrically connected to the first doped region 20 ; the second electrode 60 penetrates the passivation anti-reflection layer 70 and is electrically connected to the second doped region 30 .

[0071] Furthermore, the first electrode 50 penetrates the passivation anti-reflection layer 70 and is electrically connected to the first doping layer 21 ; the second electrode 60 penetrates the passivation anti-reflection layer 70 and is electrically connected to the second doping layer 31 .

[0072] Furthermore, the silicon substrate 10 can be a P-type silicon wafer or an N-type silicon wafer. The front side of the silicon substrate 10 has a velvet structure, so that the light is reflected by the velvet structure and the light is used multiple times, thereby reducing the reflectivity of the front side of the back contact solar cell. The front side of the silicon substrate 10 is also provided with a passivation anti-reflection layer 70.

[0073] The back-contact solar cell provided by the utility model is provided with a first doped region and a second doped region which are alternately arranged and staggered in the thickness direction of the silicon substrate on the back side of a silicon substrate, that is, the first doped region and the second doped region are staggered in the thickness direction so that the first doped region and the second doped region are not in contact with each other, so that there is no need to set a horizontal interval between the first doped region and the second doped region, and the projections of adjacent first doped regions and second doped regions on the plane where the cross section of the silicon substrate is located partially overlap or the edges are adjacent, which effectively increases the available area of ​​the back side of the back-contact solar cell, greatly improves the fill factor and the short-circuit current of the back-contact solar cell, and makes the back-contact solar cell have a higher photoelectric conversion efficiency.

[0074] The following describes in detail the manufacturing process of the back-contact solar cell provided by the embodiment of the utility model through several specific embodiments.

[0075] Example 1

[0076] A P-type silicon wafer is selected as the silicon substrate and double-sided texturing and polishing are performed on it.

[0077] A first tunneling oxide layer, a P-type doped polysilicon layer and a first mask layer are sequentially grown on the back side of the silicon substrate in a direction away from the silicon substrate.

[0078] Based on the predetermined position and size of the groove, the first tunneling oxide layer, the P-type doped polysilicon layer and the first mask layer at the corresponding position on the back side of the silicon substrate are removed by laser to form a groove, and the damaged layer caused by the laser in the groove is removed by alkaline solution, wherein the angle between the side surface of the groove and the bottom surface of the groove is 85°.

[0079] A second tunneling oxide layer, an N-type doped polysilicon layer and a second mask layer are sequentially grown on the back side of the silicon substrate in a direction away from the silicon substrate. The area where the first tunneling oxide layer and the P-type doped polysilicon layer are located on the platform adjacent to the groove is used as the first doping area, and the area where the second tunneling oxide layer and the N-type doped polysilicon layer are located in the groove is used as the second doping area. The projection of the first doping area on a plane parallel to the cross section of the silicon substrate and the projection of the second doping area on a plane parallel to the cross section of the silicon substrate partially overlap, so that the sum of the projection area S1 of the first doping area on a plane parallel to the cross section of the silicon substrate and the projection area S2 of the second doping area on a plane parallel to the cross section of the silicon substrate is greater than the projection area S3 of the silicon substrate on the plane.

[0080] The second tunneling oxide layer, the N-type doped polysilicon layer, and the second mask layer above the first doped region are removed by laser region, and the first tunneling oxide layer and the P-type doped polysilicon layer of the first doped region and the first mask layer above the first doped region are retained. The second doped region in the groove and the second mask layer above the second doped region are not processed.

[0081] The front side of the silicon substrate is textured with an alkali solution, so that the front side of the silicon substrate has a velvet structure. Since the first mask layer and the second mask layer exist on the back side of the silicon substrate, the back side of the silicon substrate can be protected from the corrosion of the alkali solution. After the texturing is completed, the first mask layer and the second mask layer are removed with a hydrogen fluoride (HF) solution.

[0082] After removing the first mask layer and the second mask layer, the front and back sides of the silicon substrate are passivated to form passivation anti-reflection layers on the front and back sides, respectively. A first electrode is used to penetrate the passivation anti-reflection layer above the first doped region and electrically connect to the P-type doped polysilicon layer, and a second electrode is used to penetrate the passivation anti-reflection layer above the second doped region and electrically connect to the N-type doped polysilicon layer, so as to obtain Figure 5 A back-contact solar cell is shown.

[0083] Example 2

[0084] Different from Example 1, on the platform adjacent to the groove on the back side of the silicon substrate, the area where the first intrinsic amorphous silicon layer and the N-type doped amorphous silicon layer exist in sequence in the direction away from the silicon substrate is used as the first doped region; in the groove on the back side of the silicon substrate, the second intrinsic amorphous silicon layer and the P-type doped amorphous silicon layer exist in sequence in the direction away from the silicon substrate is used as the second doped region. The angle between the side surface of the groove and the bottom surface of the groove is 90. The projection of the first doped region on the plane parallel to the cross-section of the silicon substrate and the projection edge of the second doped region on the plane parallel to the cross-section of the silicon substrate are adjacent, so that the sum of the projection area S1 of the first doped region on the plane parallel to the cross-section of the silicon substrate and the projection area S2 of the second doped region on the plane parallel to the cross-section of the silicon substrate is equal to the projection area S3 of the above-mentioned silicon substrate on the plane. Finally, the following is obtained: Figure 6 A back-contact solar cell is shown.

[0085] Example 3

[0086] The difference from Example 2 is that, on the platform on the back side of the silicon substrate adjacent to the groove, the area where the N+ doped layer on the silicon substrate is located is used as the first doped area; in the groove on the back side of the silicon substrate, the area where the P+ doped layer on the silicon substrate is located is used as the second doped area. Figure 4 A back-contact solar cell is shown.

[0087] In the description of the present invention, it is necessary to understand that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0088] The introduction provided in the above steps is only used to help understand the method, structure and core idea of ​​the utility model. For ordinary technicians in this technical field, the utility model can also be improved and modified without departing from the principle of the utility model, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. A back contact solar cell, characterized in that: include: Silicon substrate (10); The back side of the silicon substrate (10) is alternately provided with first doped regions (20) and second doped regions (30), wherein the first doped regions (20) and the second doped regions (30) are staggered in the thickness direction of the silicon substrate (10); The projections of the adjacent first doping regions (20) and second doping regions (30) on a plane parallel to the cross section of the silicon substrate (10) partially overlap or have edges that are adjacent; The doping type of the first doping region (20) is opposite to the doping type of the second doping region (30).

2. The back contact solar cell according to claim 1, characterized in that: Also includes: A plurality of grooves (40) are arranged at intervals on the back side of the silicon substrate (10), wherein the angle between the side surface (41) of the groove and the bottom surface (42) of the groove is less than or equal to 90°; The first doped region (20) is arranged on a platform adjacent to the groove (40), and the second doped region (30) is arranged in the groove (40).

3. The back contact solar cell according to claim 2, characterized in that: The angle between the side surface (41) of the groove (40) and the bottom surface (42) of the groove is not less than 70°; and / or, The depth of the groove (40) is 3 μm to 10 μm; and / or, The bottom surface (42) of the groove has a width of 500 μm to 1000 μm; and / or, The width of the platform adjacent to the groove (40) is 400 μm to 600 μm.

4. The back contact solar cell according to claim 1 or 2, characterized in that: The first doping region (20) comprises: a first doping layer (21); The second doping region (30) comprises: a second doping layer (31).

5. The back contact solar cell according to claim 4, characterized in that: The first doped region (20) further comprises: a first tunneling oxide layer (22) or a first intrinsic amorphous silicon layer (23) arranged between the first doped layer (21) and the silicon substrate (10); The second doped region (30) further comprises: a second tunneling oxide layer (32) or a second intrinsic amorphous silicon layer (33) arranged between the second doped layer (31) and the silicon substrate (10).

6. The back contact solar cell according to claim 5, characterized in that: When the first doped region (20) includes the first tunneling oxide layer (22), and the second doped region (30) includes the second tunneling oxide layer (32), The thickness of the first tunneling oxide layer (22) and the second tunneling oxide layer (32) is 0.5 nm-3.0 nm; The thickness of the first doping layer (21) and the second doping layer (31) is 50nm-300nm.

7. The back contact solar cell according to claim 5, characterized in that: When the first doped region (20) includes the first intrinsic amorphous silicon layer (23), and the second doped region (30) includes the second intrinsic amorphous silicon layer (33), The thickness of the first intrinsic amorphous silicon layer (23) and the second intrinsic amorphous silicon layer (33) is 5nm-10nm; The thickness of the first doping layer (21) and the second doping layer (31) is 10 nm-30 nm.

8. The back contact solar cell according to claim 1, characterized in that: Also includes: A passivation anti-reflection layer (70) is arranged on the first doped region (20) and the second doped region (30).

9. The back contact solar cell according to claim 8, characterized in that: Also includes a first electrode (50) and a second electrode (60); The first electrode (50) penetrates the passivation anti-reflection layer (70) and is electrically connected to the first doped region (20); The second electrode (60) penetrates the passivation anti-reflection layer (70) and is electrically connected to the second doped region (30).

10. The back contact solar cell according to claim 1, characterized in that: The front side of the silicon substrate (10) has a velvet structure.

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