HBC solar cell and preparation method therefor

Abstract

An HBC solar cell and a preparation method therefor, relating to the technical field of solar cells. The cell comprises: a silicon substrate (10), and a plurality of first doped regions (20), a plurality of second doped regions (30) and a plurality of isolation regions (40) which are arranged on a first main surface of the silicon substrate (10), wherein the plurality of first doped regions (20) and the plurality of second doped regions (30) are arranged in an interdigitated pattern on the first main surface, and the doping type of the first doped regions (20) is opposite to that of the second doped regions (30); in an edge region of the first main surface, the plurality of first doped regions (20) are communicated with each other; and the isolation regions (40) are located between the first doped regions (20) and the second doped regions (30). By means of optimization design of distribution structures of the first doped regions (20) and the second doped regions (30) in the first main surface of the silicon substrate (10), a TCO film can completely cover the first main surface of the cell, thereby improving the current collection capability of the HBC solar cell and enhancing the cell performance.

Description

An HBC solar cell and its preparation method

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411178020.8, filed on August 26, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of solar cell technology, and more particularly to an HBC solar cell and a method for its fabrication. Background Technology

[0004] Transparent conductive oxide thin films (TCO films) are widely used in solar cells due to their high light transmittance and low resistivity. When TCO films are applied to back-contact crystalline silicon heterojunction (HBC) solar cells, if the TCO film is laid across the entire back of the cell, contact between the TCO film covering the p-doped region and the silicon substrate or the TCO film covering the n-doped region at the cell edge can lead to edge short circuits or leakage.

[0005] Therefore, when laying a TCO film on the back of an HBC solar cell, the TCO film is generally placed at a certain distance from the edge of the cell to avoid edge short circuits or leakage. However, this design inevitably results in the TCO film area being smaller than the back area of ​​the HBC solar cell, thus greatly limiting the cell's current collection capacity.

[0006] How to design the distribution of the two doped regions on the back of an HBC solar cell so that the TCO film can cover the entire back surface has become an urgent problem to be solved. Summary of the Invention

[0007] In view of this, the present disclosure provides an HBC solar cell and a preparation method thereof. By designing the distribution structure of the first doped region and the second doped region on the first main surface of the HBC solar cell, the first doped region is connected in the edge region of the first main surface. This solves the problem that the transparent conductive oxide film of the first doped region and the second doped region can not cover the entire first main surface due to short circuit or leakage caused by contact at the edge of the cell.

[0008] To achieve the above objectives, in a first aspect, embodiments of this disclosure provide an HBC solar cell, comprising: a silicon substrate;

[0009] A plurality of first doped regions, a plurality of second doped regions, and a plurality of isolation regions are disposed on the first main surface of the silicon substrate; wherein...

[0010] Multiple first doped regions and multiple second doped regions are arranged in an interdigitated pattern on the first main surface, and the doping type of the first doped regions is opposite to that of the second doped regions.

[0011] In the edge region of the first main surface, multiple first doped regions are interconnected;

[0012] The isolation region is located between the first doped region and the second doped region.

[0013] Secondly, a method for preparing an HBC solar cell is provided, which is used to prepare the HBC solar cell as described above.

[0014] One embodiment disclosed above has the following advantages or beneficial effects: By designing the distribution structure of the first doped region and the second doped region in the first main surface of the silicon substrate, multiple first doped regions are connected in the edge region of the first main surface, so that the first doped regions cover the edge region of the first main surface of the silicon substrate. This avoids short circuits and leakage caused by the TCO film of the first doped region and the TCO film of the second doped region contacting each other at the edge of the cell. Thus, the TCO film can cover the entire first main surface of the silicon substrate, solving the problem that the TCO film in HBC solar cells needs to be a certain distance from the edge, which prevents the TCO film from completely covering the first main surface of the silicon substrate. This increases the area of ​​the TCO film, greatly improves the current collection capability of the HBC solar cell, improves the photoelectric conversion efficiency, and enhances the performance of the cell.

[0015] The further effects of the aforementioned unconventional alternative methods will be explained below in conjunction with specific implementation methods. Attached Figure Description

[0016] The accompanying drawings are provided to better understand this disclosure and do not constitute an undue limitation thereof. Wherein:

[0017] Figure 1 is a schematic diagram of the distribution structure of the first doped region and the second doped region in the first main surface of the HBC solar cell in the prior art;

[0018] Figure 2 is a schematic diagram of the first main surface of an HBC solar cell covered with a TCO film in the prior art;

[0019] Figure 3 is a schematic diagram of the distribution structure of the first doped region and the second doped region in the first main surface of the HBC solar cell according to an embodiment of the present disclosure.

[0020] Figure 4 is a schematic diagram of the first main surface of an HBC solar cell covered with a TCO film according to an embodiment of the present disclosure;

[0021] Figure 5 is a schematic diagram of a first type of longitudinal cross-section of an HBC solar cell according to an embodiment of the present disclosure;

[0022] Figure 6 is a schematic diagram of a second type of longitudinal cross-section of an HBC solar cell according to an embodiment of the present disclosure;

[0023] Figure 7 is a schematic diagram of a third structure of the longitudinal section of an HBC solar cell according to an embodiment of the present disclosure;

[0024] Figure 8 is a fourth structural schematic diagram of the longitudinal section of an HBC solar cell according to an embodiment of the present disclosure.

[0025] Figure label:

[0026] 10-Silicon substrate; 20-First doped region; 21-Tunneling oxide layer; 22-First doped layer; 23-First intrinsic thin film; 24-First doped silicon-containing thin film; 30-Second doped region; 31-Second intrinsic thin film; 32-Second doped silicon-containing thin film; 40-Isolation region; 41-Insulating isolation layer; 42-Isolation trench; 50-Transparent conductive oxide thin film (TCO film); 60-Third intrinsic thin film; 70-Antireflection layer; 80-Third doped silicon-containing thin film; 90-Second doped layer; 100-First metal electrode; 200-Second metal electrode. Detailed Implementation

[0027] Due to its high transmittance and conductivity, the TCO film enables HBC solar cells covered with the TCO film to have lower series resistance and higher fill factor. The larger the coverage area of ​​the TCO film on the first main surface of the HBC solar cell, the stronger the current collection capability and the higher the photoelectric conversion efficiency.

[0028] The existing HBC solar cell has a distribution structure of the first doped region and the second doped region in the first main surface of the silicon substrate as shown in Figure 1. There are two kinds of edge regions in the first main surface: edge regions parallel to the y direction and edge regions parallel to the x direction. The edge regions may contain either the first doped region or the second doped region.

[0029] When a TCO film is deposited on the first main surface of a silicon substrate, whether in an edge region parallel to the y-direction or an edge region parallel to the x-direction, once the TCO films of multiple first doped regions and multiple second doped regions extend beyond the boundary of the edge region, the TCO films of adjacent first doped regions and second doped regions may come into contact, or the TCO films of doped regions with different doping types from the silicon substrate may come into contact with the silicon substrate, thereby causing short circuit or leakage problems.

[0030] In existing HBC solar cells, to avoid short circuits or leakage caused by the TCO films of the first and second doped regions contacting each other at the edge, referring to Figure 2, the prepared TCO film needs to be a certain distance from the edge of the cell, so that the TCO film cannot cover the entire area of ​​the first main surface. The area of ​​the TCO film is smaller than the area of ​​the first main surface, which limits the photoelectric conversion efficiency of the HBC solar cell.

[0031] The exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, including various details of the embodiments to aid understanding, and should be considered merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of this disclosure. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0032] In the embodiments of this disclosure, "from inside to outside" refers to the direction extending sequentially from the silicon substrate towards the surface of the HBC battery.

[0033] The terms "first," "second," etc., used in the embodiments of this disclosure are used to distinguish between different structures, identical structures that are not visible, or structures located in different positions, and are not intended to limit the number or order of structures or components. For example, the first main surface of the silicon substrate is the main surface of the HBC solar cell that faces away from sunlight when it is working, i.e., the main surface away from sunlight; the second main surface of the silicon substrate is the main surface of the HBC solar cell that faces sunlight when it is working, i.e., the main surface close to sunlight.

[0034] Figure 3 is a schematic diagram of the distribution structure of the first doped region and the second doped region in the first main surface of the silicon substrate of the HBC solar cell according to an embodiment of the present disclosure.

[0035] As shown in Figure 3, the HBC solar cell of this embodiment mainly includes: a silicon substrate 10; a plurality of first doped regions 20, a plurality of second doped regions 30, and a plurality of isolation regions 40 disposed on a first main surface of the silicon substrate 10; wherein, the plurality of first doped regions 20 and the plurality of second doped regions 30 are arranged in an interdigitated manner on the first main surface, and the doping type of the first doped regions 20 is opposite to that of the second doped regions 30; the plurality of first doped regions 20 are connected in the edge region of the first main surface; the isolation region 40 is located between the first doped regions 20 and the second doped regions 30.

[0036] The aforementioned doping types include p-type doping and n-type doping, the difference being the doping element. P-type doping uses trivalent elements such as boron or gallium as the doping element, while n-type doping uses pentavalent elements such as phosphorus. Here, when the first doping region 20 is p-type doped, the second doping region 30 should be n-type doped; conversely, when the first doping region 20 is n-type doped, the second doping region 30 should be p-type doped. Preferably, when the silicon substrate 10 is n-type doped, the first doping region 20 is n-type doped, and the second doping region 30 is p-type doped.

[0037] Referring to Figure 3, in the first main surface of the silicon substrate 10, first doped regions 20 are provided in the edge regions parallel to the y-direction. Multiple first doped regions 20 extend to two edge regions parallel to the x-direction, making the multiple first doped regions 20 connected in the edge regions of the first main surface. Therefore, in the HBC solar cell provided in this embodiment, all four edge regions of the first main surface are first doped regions 20, and there are no second doped regions 30. The isolation region 40, indicated by the dashed line, is located between the first doped region 20 and the second doped region 30, and is used to isolate the first doped region 20 and the second doped region 30, thereby preventing leakage.

[0038] By designing the distribution structure of the first doped region 20 and the second doped region 30 on the first main surface of the silicon substrate 10, each edge region is a first doped region 20, and there is no second doped region 30. When a TCO film 50 is present on the first main surface, since only one type of doped region exists in the edge region, the TCO film 50 of the first doped region 20 and the second doped region 30 avoids contact between them in the edge region. Referring to Figure 4, in this case, after the TCO film 50 is prepared, it can cover the entire area of ​​the first main surface. At this time, there will be no short circuit or leakage problem at the edge, which solves the problem that the TCO film 50 cannot cover the edge region of the first main surface of the HBC solar cell. This increases the coverage area of ​​the TCO film 50, enhances the current collection capability of the HBC solar cell, and further improves the photoelectric conversion efficiency of the cell.

[0039] Furthermore, the doping type of the silicon substrate 10 is the same as that of the first doped region 20. Since the entire edge region of the first main surface of the silicon substrate 10 is provided with the first doped region 20, setting the doping type of the first doped region 20 to be the same as that of the silicon substrate 10 avoids leakage and short circuits caused by contact between the TCO film 50 covering the first doped region 20 and the silicon substrate 10. Specifically, when the silicon substrate 10 is an n-type silicon substrate 10, the doping type of the first doped region 20 should be n-type doping; when the silicon substrate 10 is a p-type silicon substrate 10, the doping type of the first doped region 20 should be p-type doping.

[0040] In an optional embodiment, as shown in FIG3, the width W1 of the edge region can be set to 50 μm < W1 < 1 mm. By setting the width of the edge region, the edge region has sufficient width to accommodate the first doped region 20, further reducing the possibility of contact between the TCO film 50 of the second doped region 30 and the TCO film 50 of the first doped region 20.

[0041] In an optional embodiment, as shown in FIG5, the first doped region 20 may include a tunneling oxide layer 21, a first doped layer 22, and a transparent conductive oxide film 50 stacked from the inside to the outside.

[0042] Specifically, the tunneling oxide layer 21 comprises silicon oxide; the first doped layer 22 comprises doped polysilicon, the doping type of which indicates the doping type of the first doped region 20. Furthermore, the first doped layer 22 is obtained by depositing polysilicon on the surface of the tunneling oxide layer 21 and then doping the polysilicon.

[0043] It is understandable that when the silicon substrate 10 is an n-type silicon substrate 10, the doped polysilicon can be n-type doped polysilicon, thereby forming a first doped layer 22 with n-type doping, so that the doping type of the first doped region 20 is n-type doped; when the silicon substrate 10 is a p-type silicon substrate 10, the doped polysilicon can be p-type doped polysilicon, thereby forming a first doped layer 22 with p-type doping, so that the doping type of the first doped region 20 is p-type doped.

[0044] TCO film 50 is a thin film composed of multiple layers, stacks, or mixtures of one or more doped metal oxides or doped metal nitrides, wherein the metal oxides in the doped metal oxides include, but are not limited to, indium oxide, tin oxide, zinc oxide, cadmium oxide, and titanium nitride; the metal nitrides in the doped metal nitrides include, but are not limited to, titanium nitride; and the doping elements in the doped metal oxides or doped metal nitrides include, but are not limited to, indium, tin, calcium, aluminum, cadmium, zinc, cerium, and fluorine.

[0045] In an optional embodiment, as shown in FIG7, the first doped region 20 may include a first intrinsic thin film 23, a first doped silicon-containing thin film 24, and a transparent conductive oxide thin film 50 stacked from the inside to the outside.

[0046] Specifically, the first intrinsic thin film 23 includes, but is not limited to, a thin film composed of a single layer, multiple layers, or stack of one or more silicon-containing thin films, or a thin film composed of any mixture of silicon, silicon oxide, or silicon carbide. The silicon-containing thin film includes at least one thin film containing silicon, silicon oxide, or silicon nitride. It should be noted that the silicon, silicon oxide, or silicon carbide in the first intrinsic thin film 23 refers to microcrystalline, nanocrystalline, or amorphous silicon, silicon oxide, or silicon carbide.

[0047] The first doped silicon-containing thin film 24 includes, but is not limited to, a thin film composed of a single layer, multiple layers, or stack of one or more doped silicon-containing thin films, or a thin film composed of any mixture of doped silicon, doped silicon oxide, or doped silicon carbide. The doped silicon-containing thin film includes at least one thin film containing doped silicon, doped silicon oxide, or doped silicon carbide. It should be noted that the doped silicon, doped silicon oxide, or doped silicon carbide in the first doped silicon-containing thin film 24 refers to microcrystalline, nanocrystalline, or amorphous doped silicon, doped silicon oxide, or doped silicon carbide.

[0048] Understandably, the doping type of the first doped silicon thin film 24 indicates the doping type of the first doped region 20.

[0049] Furthermore, the thickness of the first doped silicon-containing thin film 24 is 1 nm to 50 nm. As an example, the thickness of the first doped silicon-containing thin film 24 can be 1 nm, 5 nm, 20 nm, 35 nm, or 50 nm, etc.

[0050] In one optional embodiment, as shown in Figures 5, 6, 7 and 8, the second doped region 30 includes a second intrinsic thin film 31, a second doped silicon-containing thin film 32 and a transparent conductive oxide thin film 50 stacked from the inside to the outside.

[0051] Specifically, the second intrinsic thin film 31 includes, but is not limited to, a thin film composed of a single layer, multiple layers, or stack of one or more silicon-containing thin films, or a thin film composed of any mixture of silicon, silicon oxide, or silicon carbide. The silicon-containing thin film includes at least one thin film containing silicon, silicon oxide, or silicon nitride. It should be noted that the silicon, silicon oxide, or silicon carbide in the second intrinsic thin film 31 refers to microcrystalline, nanocrystalline, or amorphous silicon, silicon oxide, or silicon carbide.

[0052] The second doped silicon-containing thin film 32 includes, but is not limited to, a thin film composed of a single layer, multiple layers, or stack of one or more doped silicon-containing thin films, or a thin film composed of any mixture of doped silicon, doped silicon oxide, or doped silicon carbide. The doped silicon-containing thin film includes at least one thin film containing doped silicon, doped silicon oxide, or doped silicon carbide. It should be noted that the doped silicon, doped silicon oxide, or doped silicon carbide in the first doped silicon-containing thin film 24 refers to microcrystalline, nanocrystalline, or amorphous doped silicon, doped silicon oxide, or doped silicon carbide.

[0053] Understandably, the doping type of the second doped silicon thin film 32 indicates the doping type of the second doped region 30. The doping type of the first doped silicon thin film 24 or the first doped layer 22 is the opposite of the doping type of the second doped silicon thin film 32.

[0054] Furthermore, the thickness of the second doped silicon thin film 32 is 1 nm to 50 nm. As an example, the thickness of the first doped silicon thin film 24 can be 1 nm, 5 nm, 20 nm, 35 nm, or 50 nm, etc.

[0055] In an optional embodiment, as shown in Figures 5 and 8, the HBC solar cell further includes a third intrinsic thin film 60 and an antireflection layer 70 stacked from the inside to the outside on the second main surface of the silicon substrate 10.

[0056] Specifically, the third intrinsic thin film 60 includes, but is not limited to, a thin film composed of a single layer, multiple layers, or stack of one or more silicon-containing thin films, or a thin film composed of any mixture of silicon, silicon oxide, or silicon carbide. The silicon-containing thin film includes at least one thin film containing silicon, silicon oxide, or silicon nitride. It should be noted that the silicon, silicon oxide, or silicon carbide in the third intrinsic thin film 60 refers to microcrystalline, nanocrystalline, or amorphous silicon, silicon oxide, or silicon carbide.

[0057] The thickness of the third intrinsic thin film 60 is 1 nm to 15 nm. As an example, the thickness of the third intrinsic thin film 60 can be 1 nm, 2 nm, 7 nm, 10 nm, or 15 nm, etc.

[0058] The antireflection layer 70 is at least one of aluminum oxide, silicon oxide, gallium oxide, silicon nitride, aluminum nitride, silicon oxynitride, aluminum oxynitride, magnesium fluoride, lithium fluoride, zinc oxide, and indium tin oxide semiconductor transparent conductive film (ITO).

[0059] The thickness of the antireflection layer 70 is 40nm-200nm. As an example, the thickness of the antireflection layer 70 can be 40nm, 80nm, 100nm, 150nm, or 200nm, etc.

[0060] Furthermore, as shown in Figure 6, the HBC solar cell further includes a third doped silicon-containing thin film 80 disposed between the aforementioned third intrinsic thin film 60 and the aforementioned antireflection layer 70.

[0061] Specifically, the third-doped silicon-containing thin film 80 includes, but is not limited to, a thin film composed of a single layer, multiple layers, or stack of one or more doped silicon-containing thin films, or a thin film composed of any mixture of doped silicon, doped silicon oxide, or doped silicon carbide. The doped silicon-containing thin film includes at least one of doped silicon, doped silicon oxide, or doped silicon carbide. It should be noted that the doped silicon, doped silicon oxide, or doped silicon carbide in the third-doped silicon-containing thin film 80 refers to microcrystalline, nanocrystalline, or amorphous doped silicon, doped silicon oxide, or doped silicon carbide.

[0062] The thickness of the third-doped silicon thin film 80 is 0-15 nm. As an example, the thickness of the third-doped silicon thin film 80 can be 0.1 nm, 2 nm, 7 nm, 10 nm or 15 nm, etc.

[0063] In an optional embodiment, as shown in FIG7, the HBC solar cell further includes a second doped layer 90 and an antireflection layer 70 stacked from the inside to the outside on the second main surface of the silicon substrate 10.

[0064] The second doped layer 90 is obtained by doping the silicon substrate 10 on the second main surface of the silicon substrate 10. The doping type of the second doped layer 90 can be the same as that of the first doped layer 22.

[0065] In an optional embodiment, since different functional layers may exist in the first doped region 20 and the second doped region 30, the isolation region 40 located between the first doped region 20 and the second doped region 30 may have different structures. When the first doped region 20 includes a tunneling oxide layer 21 and a first doped layer 22, the isolation region 40 may include the structure shown in FIG. 5.

[0066] As shown in Figure 5, the isolation region 40 includes the tunneling oxide layer 21, the first doped layer 22, the insulating isolation layer 41, the second intrinsic thin film 31, the second doped silicon-containing thin film 32, and the transparent conductive oxide thin film 50, which are stacked from the inside to the outside.

[0067] When the first doped region 20 includes the first intrinsic thin film 23 and the first doped silicon-containing thin film 24, the isolation region 40 may include the two structures shown in FIG7 and FIG8.

[0068] As shown in Figure 7, the isolation region 40 includes the first intrinsic thin film 23, the first doped silicon-containing thin film 24, the insulating isolation layer 41, the second intrinsic thin film 31, the second doped silicon-containing thin film 32, and the transparent conductive oxide thin film 50, which are stacked from the inside to the outside.

[0069] As shown in Figure 8, the isolation region 40 includes the second intrinsic thin film 31, the second doped silicon-containing thin film 32, the insulating isolation layer 41, the first intrinsic thin film 23, the first doped silicon-containing thin film 24, and the transparent conductive oxide thin film 50, which are stacked from the inside to the outside.

[0070] A portion of the functional layer originally belonging to the first doped region 20 overlaps with a portion of the functional layer originally belonging to the second doped region 30. An insulating layer 41 separates the functional layers belonging to the first doped region 20 and the second doped region 30 in the overlapping portion, thus forming an isolation region 40 to prevent leakage caused by contact between the two layers. The width of the isolation region 40 is 10μm-300μm. For example, the width of the isolation region 40 can be 10μm, 50μm, 150μm, 200μm, or 300μm.

[0071] Specifically, the insulating layer 41 includes at least one of aluminum oxide, silicon oxide, gallium oxide, silicon nitride, aluminum nitride, silicon oxynitride, and aluminum oxynitride.

[0072] Furthermore, the isolation region 40 is provided with an isolation groove 42; the isolation groove 42 is formed by at least removing the aforementioned transparent conductive oxide film 50. As an example, as shown in Figures 5 and 6, the isolation groove 42 is formed by removing a portion of the TCO film 50 in the isolation region 40.

[0073] Furthermore, to further reduce the probability of short circuits and leakage, the functional layers above the insulating isolation layer 41, i.e., those extending away from the silicon substrate 10, can be removed together. As an example, as shown in FIG7, the TCO film 50 and the functional layers above the insulating isolation layer 41—the second intrinsic film 31 and the second doped silicon-containing film 32—are removed together to form an isolation trench 42; as shown in FIG8, the TCO film 50 and the functional layers above the insulating isolation layer 41—the first intrinsic film 23 and the first doped silicon-containing film 24—are removed together to form an isolation trench 42.

[0074] The width of the isolation groove 42 is 10μm-200μm. As an example, the width of the isolation groove 42 can be 10μm, 50μm, 100μm, 150μm or 200μm, etc.

[0075] The TCO film 50 covering the first doped region 20 and the TCO film 50 covering the second doped region 30 are disconnected by the isolation trench 42 so that they do not contact each other, thus avoiding short circuits and leakage.

[0076] In one optional embodiment, the HBC solar cell further includes a first metal electrode 100 disposed in the first doped region 20 and a second metal electrode 200 disposed in the second doped region 30.

[0077] Specifically, the first metal electrode 100 is electrically connected to the TCO film 50 of the first doped region 20, and the second metal electrode 200 is electrically connected to the TCO film 50 of the second doped region 30. The first metal electrode 100 and the second metal electrode 200 are multilayer electrodes composed of one or more of the following: silver electrode, silver alloy electrode, copper electrode, and copper alloy electrode; or, multilayer electrodes composed of nickel, copper, and silver.

[0078] In an optional embodiment, as shown in FIG8, the HBC solar cell further includes a TCO film 50 disposed on the antireflection layer 70 in the direction away from the silicon substrate 10. To enable the HBC solar cell to have superior cell performance, the TCO film 50 can be disposed on the second main surface of the cell.

[0079] It is worth noting that Figures 5-8 only illustrate the relative positional relationship between a second doped region and its two adjacent first doped regions.

[0080] According to the HBC solar cell of this disclosure, by designing the distribution structure of the first doped region and the second doped region in the first main surface of the silicon substrate, multiple first doped regions are connected in the edge region of the first main surface, so that the first doped regions cover the edge region of the first main surface of the silicon substrate. This avoids short circuits and leakage caused by the TCO film of the first doped region and the TCO film of the second doped region contacting each other at the edge of the cell. Thus, the TCO film can cover the entire first main surface of the silicon substrate, solving the problem that the TCO film in the HBC solar cell needs to be at a certain distance from the edge, which prevents the TCO film from completely covering the first main surface of the silicon substrate. This increases the area of ​​the TCO film, greatly improves the current collection capability of the HBC solar cell, improves the photoelectric conversion efficiency, and enhances the performance of the cell.

[0081] This disclosure also provides a method for preparing an HBC solar cell, used to prepare any of the HBC solar cells described above.

[0082] Since the TCO film in this embodiment can completely cover the first main surface of the silicon substrate, there is no need to design the size of the TCO film; the length and width of the HBC solar cell can be used directly.

[0083] The TCO film coating process eliminates the need to block the edges of the first main surface of the silicon substrate, or to etch the TCO film at the edges of the first main surface of the silicon substrate after coating. This simplifies the fabrication process of HBC solar cells and improves the fabrication efficiency of the cells.

[0084] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. An HBC solar cell, comprising: Silicon substrate (10); A plurality of first doped regions (20), a plurality of second doped regions (30), and a plurality of isolation regions (40) are disposed on the first main surface of the silicon substrate (10); wherein, Multiple first doped regions (20) and multiple second doped regions (30) are arranged in an interdigitated pattern on the first main surface, and the doping type of the first doped region (20) is opposite to that of the second doped region (30). In the edge region of the first main surface, a plurality of the first doped regions (20) are connected; The isolation region (40) is located between the first doped region (20) and the second doped region (30).

2. The HBC solar cell according to claim 1, wherein, The first doped region (20) includes a tunneling oxide layer (21), a first doped layer (22), and a transparent conductive oxide film (50) stacked from the inside to the outside.

3. The HBC solar cell according to claim 1, wherein, The first doped region (20) includes a first intrinsic thin film (23), a first doped silicon-containing thin film (24), and a transparent conductive oxide thin film (50) stacked from the inside to the outside.

4. The HBC solar cell according to claim 2 or 3, wherein, The second doped region (30) includes a second intrinsic thin film (31), a second doped silicon-containing thin film (32), and a transparent conductive oxide thin film (50) stacked from the inside to the outside.

5. The HBC solar cell according to claim 1, further comprising: The second main surface of the silicon substrate (10) is provided with a third intrinsic thin film (60) and an antireflection layer (70) stacked from the inside to the outside.

6. The HBC solar cell according to claim 5, further comprising: A third doped silicon-containing thin film (80) is disposed between the third intrinsic thin film (60) and the antireflection layer (70).

7. The HBC solar cell according to claim 1, further comprising: The second main surface of the silicon substrate (10) is provided with a second doped layer (90) and an anti-reflection layer (70) stacked from the inside to the outside.

8. The HBC solar cell according to claim 4, wherein, In the case where the first doped region (20) includes a tunneling oxide layer (21) and a first doped layer (22), The isolation region (40) includes the tunneling oxide layer (21), the first doped layer (22), the insulating isolation layer (41), the second intrinsic thin film (31), the second doped silicon-containing thin film (32), and the transparent conductive oxide thin film (50) stacked from the inside to the outside; In the case where the first doped region (20) includes the first intrinsic thin film (23) and the first doped silicon-containing thin film (24), The isolation region (40) includes the first intrinsic thin film (23), the first doped silicon-containing thin film (24), the insulating isolation layer (41), the second intrinsic thin film (31), the second doped silicon-containing thin film (32), and the transparent conductive oxide thin film (50) stacked from the inside to the outside; or, The isolation region (40) includes the second intrinsic thin film (31), the second doped silicon-containing thin film (32), the insulating isolation layer (41), the first intrinsic thin film (23), the first doped silicon-containing thin film (24), and the transparent conductive oxide thin film (50) stacked from the inside to the outside.

9. The HBC solar cell according to claim 8, wherein, The isolation zone (40) is provided with an isolation trough (42); The isolation groove (42) is formed by at least removing the transparent conductive oxide film (50).

10. The HBC solar cell according to claim 1, further comprising: A first metal electrode (100) disposed in the first doped region (20) and a second metal electrode (200) disposed in the second doped region (30).

11. The HBC solar cell according to claim 1, wherein, The doping type of the silicon substrate (10) is the same as that of the first doped region (20).

12. A method for preparing an HBC solar cell, wherein, Used to prepare HBC solar cells as described in any one of claims 1-11.

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