Solar cell and method of manufacturing the same

Abstract

The application relates to the technical field of solar cells, and mainly provides a solar cell and a preparation method thereof. The solar cell comprises a silicon substrate, the silicon substrate comprises oppositely arranged first and second surfaces, and a first passivation layer, a first TCO layer and a second passivation layer are sequentially and layerwisely arranged on the first surface of the silicon substrate in a first direction. The solar cell can effectively solve the PID problem and has good PID resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, in particular to a solar cell and a preparation method thereof. BACKGROUND

[0002] When photovoltaic modules in a photovoltaic power station are output in series, the modules may be subjected to a large positive potential or a large negative potential relative to the grounded frame, causing a potential-induced degradation (PID) phenomenon. The potential difference between the module metal frame and the cell piece drives alkali metal ions (such as sodium ions Na + ) to migrate through the encapsulating material to the surface of the cell piece, causing a large amount of charge to accumulate on the surface of the cell piece, thereby increasing the carrier recombination rate, reducing the efficiency of the cell piece, and causing the PID phenomenon. The PID phenomenon reduces the efficiency of the cell piece and has a serious impact on the power generation of the photovoltaic power station, and reduces the service life and economic benefits of the photovoltaic power station.

[0003] With the maturity of mass production technology of high-efficiency crystalline silicon cells, the downstream module end further improves the reliability requirements. Therefore, it is necessary to provide a PID-resistant solar cell. SUMMARY

[0004] The present application provides a solar cell and a preparation method thereof to solve or alleviate the technical problems proposed above. The solar cell in the technical solution of the present application can effectively solve the potential-induced degradation (PID) problem and has good PID resistance.

[0005] In a first aspect, an embodiment of the present application provides a solar cell, comprising:

[0006] a silicon substrate, the silicon substrate comprising a first surface and a second surface arranged oppositely;

[0007] a first passivation layer, a first TCO layer, and a second passivation layer are sequentially and layerwisely arranged on the first surface of the silicon substrate along a first direction.

[0008] Optionally, the first TCO layer comprises a plurality of sub-TCO layers layerwisely arranged along the first direction.

[0009] The refractive index of the sub-TCO layer close to the silicon substrate is greater than the refractive index of the sub-TCO layer away from the silicon substrate.

[0010] Optionally, the first TCO layer comprises a first sub-TCO layer, a second sub-TCO layer, and a third sub-TCO layer layerwisely arranged along the first direction.

[0011] The refractive index of the first sub-TCO layer is greater than the refractive index of the second sub-TCO layer.

[0012] The refractive index of the second sub-TCO layer is greater than the refractive index of the third sub-TCO layer.

[0013] Optionally, the material of the first sub-TCO layer is aluminum-titanium co-doped zinc oxide, wherein the total mass percentage of aluminum and titanium elements is 0.1-5%; the material of the second sub-TCO layer is gallium-doped zinc oxide, wherein the mass percentage of gallium element is 0.1-3%; and the material of the third sub-TCO layer is aluminum-doped zinc oxide, wherein the mass percentage of aluminum element is 0.1-5%.

[0014] Optionally, the refractive index of the first sub-TCO layer is 1.9-2.2, the refractive index of the second sub-TCO layer is 1.8-2.1, and the refractive index of the third sub-TCO layer is 1.7-2.0.

[0015] Optionally, the material of the first passivation layer and the material of the second passivation layer respectively and independently include one or more of Al2O3, SiN x , SiON x , TiO x .

[0016] Optionally, the material of the first passivation layer includes one or more of Al2O3, SiN x , SiON x , TiO x .

[0017] The material of the second passivation layer includes one or two of SiN x , SiON x .

[0018] Optionally, the material of the first TCO layer includes one or more of fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, boron-doped zinc oxide, aluminum-gallium co-doped zinc oxide, aluminum-titanium co-doped zinc oxide, indium tin oxide, and titanium oxide.

[0019] Optionally, in the fluorine-doped tin oxide, the mass percentage of fluorine element is 0.1-20%;

[0020] In the antimony-doped tin oxide, the mass percentage of antimony element is 0.1-20%;

[0021] In the aluminum-doped zinc oxide, the mass percentage of aluminum element is 0.1-20%;

[0022] In the gallium-doped zinc oxide, the mass percentage of gallium element is 0.1-20%;

[0023] In the boron-doped zinc oxide, the mass percentage of boron element is 0.1-20%;

[0024] The total mass percentage of aluminum and gallium in the aluminum-gallium co-doped zinc oxide is 1-20%.

[0025] The total mass percentage of aluminum and titanium in the aluminum-titanium co-doped zinc oxide is 1-20%.

[0026] Optionally, the sheet resistance of the first TCO layer is 1Ω / sq-10 6 Ω / sq.

[0027] Optionally, the solar cell is a TOPCon solar cell; the TOPCon solar cell further comprises: a first tunneling oxide layer and a first doped polysilicon layer which are sequentially stacked between the silicon substrate and the first passivation layer along a first direction; the doping type of the silicon substrate is the same as that of the first doped polysilicon layer.

[0028] Optionally, the solar cell is a BC solar cell; the BC solar cell further comprises a first region and a second region on a first surface of the silicon substrate, the first region and the second region are staggered and spaced apart from each other; the first region comprises: a second tunneling oxide layer and a second doped polysilicon layer which are sequentially stacked between the silicon substrate and the first passivation layer along a first direction; the second region comprises: a third tunneling oxide layer and a third doped polysilicon layer which are sequentially stacked between the silicon substrate and the first passivation layer along a first direction; the doping type of the silicon substrate is opposite to that of the second doped polysilicon layer; the doping type of the silicon substrate is the same as that of the third doped polysilicon layer.

[0029] Optionally, the solar cell further comprises:

[0030] a third passivation layer, a second TCO layer, and a fourth passivation layer which are sequentially stacked on a second surface of the silicon substrate along a second direction;

[0031] The second direction is opposite to the first direction.

[0032] Optionally, the solar cell is a TOPCon solar cell;

[0033] The TOPCon solar cell further comprises:

[0034] a diffusion doped layer between the silicon substrate and the first passivation layer;

[0035] a third passivation layer and a fourth passivation layer which are sequentially stacked on a second surface of the silicon substrate along a second direction; and

[0036] a first tunneling oxide layer, a first doped polysilicon layer, which are sequentially stacked between the silicon substrate and the third passivation layer along the second direction;

[0037] The doping type of the silicon substrate is opposite to the doping type of the diffusion doped layer.

[0038] The doping type of the silicon substrate is the same as the doping type of the first doped polysilicon layer.

[0039] Optionally, the solar cell is a BC solar cell.

[0040] The BC solar cell further comprises:

[0041] a third passivation layer, a fourth passivation layer, which are sequentially stacked on the second surface of the silicon substrate along the second direction; and

[0042] a first region and a second region on the second surface of the silicon substrate, the first region and the second region are staggered and spaced apart from each other.

[0043] The first region comprises: a second tunneling oxide layer, a second doped polysilicon layer, which are sequentially stacked between the silicon substrate and the third passivation layer along the second direction.

[0044] The second region comprises: a third tunneling oxide layer, a third doped polysilicon layer, which are sequentially stacked between the silicon substrate and the third passivation layer along the second direction.

[0045] The doping type of the silicon substrate is opposite to the doping type of the second doped polysilicon layer.

[0046] The doping type of the silicon substrate is the same as the doping type of the third doped polysilicon layer.

[0047] In a second aspect, the embodiments of the present application provide a preparation method of the solar cell provided by any of the above-mentioned embodiments, comprising:

[0048] providing a silicon substrate, the silicon substrate comprising a first surface and a second surface arranged oppositely;

[0049] sequentially stacking a first passivation layer, a first TCO layer, a second passivation layer on the first surface of the silicon substrate along a first direction.

[0050] The technical solutions of the above-mentioned embodiments can include the following advantages:

[0051] The solar cell of this application forms a stacked passivation structure by sequentially stacking a first passivation layer, a first TCO (transparent conductive oxide) layer, and a second passivation layer on a silicon substrate. The TCO layer has a dense texture, effectively preventing alkali metal ions from entering the silicon substrate. Furthermore, the TCO layer has good conductivity, acting as a charge transport channel to quickly conduct away accumulated charge on the cell surface, thus effectively solving the potential-induced degradation (PID) problem and exhibiting good anti-PID performance. In addition, the TCO layer is located between the two passivation layers, preventing it from directly contacting the silicon substrate and avoiding an increase in interface defect state density due to lattice mismatch. The second passivation layer encapsulates and protects the TCO layer, preventing damage from moisture and other contaminants. In summary, the solar cell of this application effectively solves the PID problem and exhibits good anti-PID performance. Attached Figure Description

[0052] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0053] Figure 1 This is a schematic diagram of the structure of the solar cell provided in Embodiment 1 of this application;

[0054] Figure 2 This is a schematic diagram of the structure of the solar cell provided in Embodiment 2 of this application;

[0055] Figure 3 This is a schematic diagram of the structure of the solar cell provided in Embodiment 3 of this application;

[0056] Figure 4 This is a schematic diagram of the structure of the solar cell provided in Embodiment 4 of this application;

[0057] Figure 5 This is a schematic diagram of the structure of the solar cell provided in Embodiment 7 of this application;

[0058] Figure 6 This is a schematic diagram of the structure of the solar cell provided in Embodiment 8 of this application;

[0059] Figure 7 This is a schematic diagram of the structure of the solar cell provided in Embodiment 9 of this application;

[0060] Figure 8 This is a schematic diagram of the structure of the solar cell provided in Embodiment 10 of this application.

[0061] Explanation of reference numerals in the attached figures:

[0062] 100. Silicon substrate;

[0063] 210, first passivation layer; 220, first TCO layer; 221, first sub-TCO layer; 222, second sub-TCO layer; 223, third sub-TCO layer; 230, second passivation layer;

[0064] 310, third passivation layer; 320, second TCO layer; 330, fourth passivation layer;

[0065] 410, first tunneling oxide layer; 420, first doped polysilicon layer; 430, second tunneling oxide layer; 440, second doped polysilicon layer; 450, third tunneling oxide layer; 460, third doped polysilicon layer; 470, diffusion doped layer;

[0066] 510, first region; 520, second region;

[0067] 610, first electrode; 620, second electrode;

[0068] D1, first direction; D2, second direction. DETAILED DESCRIPTION

[0069] Embodiments of the present application are described in detail below with reference to the accompanying drawings. In the drawings, the size and relative sizes of layers, regions, elements, and the like can be exaggerated for clarity. The same or similar components are denoted by the same or similar reference numerals throughout the drawings. The embodiments described below are examples in which the application is applied, and are merely intended to explain the application, and should not be understood as limiting the application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0070] As shown in FIG. 1, the solar cell provided by the embodiments of the present application comprises: Figures 1 to 8

[0071] a silicon substrate 100, the silicon substrate 100 comprising a first surface and a second surface arranged oppositely;

[0072] a first passivation layer 210, a first TCO layer 220, and a second passivation layer 230 are sequentially stacked on the first surface of the silicon substrate 100 along a first direction D1.

[0073] ​The solar cell of the present application forms a laminated passivation structure by sequentially stacking a first passivation layer, a first TCO (transparent conductive oxide) layer and a second passivation layer on a silicon substrate. The TCO layer is compact in texture and can effectively block alkali metal ions from entering the interior of the silicon substrate. Moreover, the TCO layer has good electrical conductivity and can quickly conduct the charges accumulated on the surface of the cell as a charge transmission channel, thereby effectively solving the problem of potential induced degradation (PID) and having good PID resistance. In addition, the TCO layer is located between the two passivation layers, so that the TCO layer is not directly in contact with the silicon substrate, and the increase in interface defect state density caused by lattice mismatch can be avoided. The second passivation layer is provided to encapsulate and protect the TCO layer from damage by water vapor and other pollutants. In summary, the solar cell of the present application can effectively solve the PID problem and has good PID resistance.

[0074] In optional embodiments, the first TCO layer comprises a plurality of sub-TCO layers stacked along the first direction;

[0075] The refractive index of the sub-TCO layer close to the silicon substrate is greater than the refractive index of the sub-TCO layer away from the silicon substrate.

[0076] When the refractive index of the sub-TCO layer close to the silicon substrate is greater than the refractive index of the sub-TCO layer away from the silicon substrate, a more excellent antireflection effect can be achieved, and the absorption of incident light by the cell piece is increased.

[0077] In some embodiments, the first TCO layer comprises a first sub-TCO layer and a second sub-TCO layer stacked along the first direction; the refractive index of the first sub-TCO layer is greater than the refractive index of the second sub-TCO layer. In some embodiments, the refractive index of the first sub-TCO layer can be 1.9-2.2, and the refractive index of the second sub-TCO layer can be 1.8-2.1.

[0078] As shown in Figure 4 and Figure 8 In optional embodiments, the first TCO layer 220 comprises a first sub-TCO layer 221, a second sub-TCO layer 222 and a third sub-TCO layer 223 stacked along the first direction D1;

[0079] The refractive index of the first sub-TCO layer is greater than the refractive index of the second sub-TCO layer;

[0080] The refractive index of the second sub-TCO layer is greater than the refractive index of the third sub-TCO layer.

[0081] The laminated passivation structure composed of a plurality of sub-TCO layers with decreasing refractive index along the first direction can more effectively capture incident light and reduce light escape, enhancing the antireflection effect.

[0082] In optional embodiments, the material of the first sub-TCO layer is aluminum-titanium co-doped zinc oxide, wherein the total mass percentage of aluminum and titanium is 0.1-5%; the material of the second sub-TCO layer is gallium-doped zinc oxide, wherein the mass percentage of gallium is 0.1-3%; and the material of the third sub-TCO layer is aluminum-doped zinc oxide, wherein the mass percentage of aluminum is 0.1-5%.

[0083] When the material of the first sub-TCO layer is aluminum-titanium co-doped zinc oxide, the material of the second sub-TCO layer is gallium-doped zinc oxide, and the material of the third sub-TCO layer is aluminum-doped zinc oxide, and the mass percentages of the doping elements are adjusted within the above ranges, the refractive index of the aluminum-titanium co-doped zinc oxide is higher than that of the gallium-doped zinc oxide, and the refractive index of the gallium-doped zinc oxide is higher than that of the aluminum-doped zinc oxide, thereby ensuring that the refractive indexes of the first sub-TCO layer, the second sub-TCO layer, and the third sub-TCO layer decrease in turn, further improving the antireflection effect and increasing the absorption of incident light by the cell sheet.

[0084] In optional embodiments, the refractive index of the first sub-TCO layer is 1.9-2.2, the refractive index of the second sub-TCO layer is 1.8-2.1, and the refractive index of the third sub-TCO layer is 1.7-2.0. When the first TCO layer is composed of multiple sub-TCO layers with the above refractive index ranges, the first TCO layer has excellent electrical conductivity and can match the second passivation layer for refractive index adjustment, thereby enhancing the antireflection effect. Specifically, the refractive index of the first sub-TCO layer can be 1.9, 2.0, 2.1, or 2.2, the refractive index of the second sub-TCO layer can be 1.8, 1.9, 2.0, or 2.1, and the refractive index of the third sub-TCO layer can be 1.7, 1.8, 1.9, or 2.0.

[0085] In optional embodiments, the material of the first passivation layer and the material of the second passivation layer each and independently include one or more of Al2O3, SiN x , SiON x , and TiO x . These passivation materials have good passivation effects and can effectively reduce the dangling bonds on the silicon surface and reduce the surface state density, thereby reducing the recombination of carriers on the surface.

[0086] In some embodiments, to enhance the passivation effect, the first passivation layer can include multiple sub-passivation layers arranged in sequence, for example, the first passivation layer includes at least two of an Al2O3 layer, a SiN x layer, a SiON x layer, and a TiO x layer, and the stacking order is not limited herein. In other embodiments, to enhance the passivation effect, the second passivation layer can include multiple sub-passivation layers arranged in sequence, for example, the second passivation layer includes at least two of an Al2O3 layer, a SiNx layer, SiON x layer, TiO x at least two of the layers, the order of which is not limited here.

[0087] In optional embodiments, the material of the first passivation layer includes one or more of Al2O3, SiN x , SiON x , TiO x ;

[0088] The material of the second passivation layer includes one or both of SiN x , SiON x .

[0089] The first passivation layer is close to the silicon substrate, and the Al2O3, SiN x , SiON x , and TiO x used by the first passivation layer has good interface passivation effect, which can reduce the recombination of carriers on the surface; the second passivation layer is far away from the silicon substrate, and the SiN x and SiON x used by the second passivation layer not only has good interface passivation effect, but also has a wider refractive index adjustment range, has better antireflection effect, and provides light absorption efficiency.

[0090] In optional embodiments, the material of the first TCO layer includes one or more of fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, boron-doped zinc oxide, aluminum-gallium co-doped zinc oxide, aluminum-titanium co-doped zinc oxide, indium tin oxide, and titanium oxide. These TCO layer materials have high transparency and good conductivity, which can ensure that the incident light is fully absorbed by the cell sheet and ensure the photoelectric conversion efficiency of the cell sheet.

[0091] In optional embodiments, in the fluorine-doped tin oxide, the mass percentage of fluorine element is 0.1-20% (for example, 0.1%, 1%, 2%, 5%, 8%, 10%, 12%, 15%, 18%, or 20%).

[0092] In optional embodiments, in the antimony-doped tin oxide, the mass percentage of antimony element is 0.1-20% (for example, 0.1%, 1%, 2%, 5%, 8%, 10%, 12%, 15%, 18%, or 20%).

[0093] In optional embodiments, in the aluminum-doped zinc oxide, the mass percentage of aluminum element is 0.1-20% (for example, 0.1%, 1%, 2%, 5%, 8%, 10%, 12%, 15%, 18%, or 20%).

[0094] In optional embodiments, the mass percentage of gallium in the gallium-doped zinc oxide is 0.1-20% (e.g., 0.1%, 1%, 2%, 5%, 8%, 10%, 12%, 15%, 18%, or 20%).

[0095] In optional embodiments, the mass percentage of boron in the boron-doped zinc oxide is 0.1-20% (e.g., 0.1%, 1%, 2%, 5%, 8%, 10%, 12%, 15%, 18%, or 20%).

[0096] In optional embodiments, the total mass percentage of aluminum and gallium in the aluminum-gallium co-doped zinc oxide is 1-20% (e.g., 0.1%, 1%, 2%, 5%, 8%, 10%, 12%, 15%, 18%, or 20%).

[0097] In optional embodiments, the total mass percentage of aluminum and titanium in the aluminum-titanium co-doped zinc oxide is 1-20% (e.g., 0.1%, 1%, 2%, 5%, 8%, 10%, 12%, 15%, 18%, or 20%).

[0098] The TCO layer material with the doping element can effectively adjust the conductivity of the TCO layer and optimize the anti-PID performance of the battery. However, if the content of the doping element is too low, the conductivity of the TCO layer is poor; if the content of the doping element is too high, the conductivity of the TCO layer will not increase, but the preparation process will become more difficult and the production cost will increase; when the content of the doping element in the TCO layer material is appropriate, the TCO layer material can have both excellent conductivity and low production cost.

[0099] In some embodiments, the thickness of the first TCO layer is 0.1-50 nm. When the thickness of the first TCO layer is less than 0.1 nm, the alkali metal ions cannot be effectively blocked, and the anti-PID effect is not achieved; when the thickness of the first TCO layer is greater than 50 nm, the parasitic absorption of the TCO layer will increase, the photoelectric conversion efficiency of the battery will decrease, and the light transmittance of the battery will decrease; when the thickness of the first TCO layer is 0.1-50 nm, the battery has good anti-PID effect and photoelectric conversion efficiency. Specifically, the thickness of the first TCO layer can be 0.1 nm, 1 nm, 3 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, or 50 nm.

[0100] In optional embodiments, the sheet resistance of the first TCO layer is 1 Ω / sq-10 6Ω / sq. In some embodiments, to ensure the conductivity of the TCO layer, the sheet resistance of the first TCO layer can be controlled to be 1Ω / sq-200Ω / sq. Specifically, the sheet resistance of the first TCO layer can be 1Ω / sq, 10Ω / sq, 20Ω / sq, 50Ω / sq, 80Ω / sq, 100Ω / sq, 150Ω / sq, or 200Ω / sq.

[0101] In this application, the solar cell can be a TOPCon (tunneling oxide passivated contact) solar cell or a BC (back contact) solar cell, and no specific limitation is made here.

[0102] In an optional embodiment, the solar cell is a TOPCon solar cell; the TOPCon solar cell further includes: a first tunneling oxide layer and a first doped polycrystalline silicon layer disposed sequentially between the silicon substrate and the first passivation layer along a first direction; the doping type of the silicon substrate is the same as the doping type of the first doped polycrystalline silicon layer.

[0103] In an optional embodiment, the first tunneling oxide layer and the first doped polycrystalline silicon layer in the TOPCon solar cell are located only in the metal region, while the non-metal region does not have the first tunneling oxide layer and the first doped polycrystalline silicon layer, and the first passivation layer located in the non-metal region is in contact with the silicon substrate.

[0104] In an optional embodiment, the solar cell is a BC (back contact) solar cell; the BC solar cell further includes a first region and a second region located on a first surface of the silicon substrate, the first region and the second region being alternately arranged and spaced apart from each other; the first region includes: a second tunneling oxide layer and a second doped polycrystalline silicon layer sequentially stacked between the silicon substrate and the first passivation layer along a first direction; the second region includes: a third tunneling oxide layer and a third doped polycrystalline silicon layer sequentially stacked between the silicon substrate and the first passivation layer along a first direction; the doping type of the silicon substrate is opposite to the doping type of the second doped polycrystalline silicon layer; the doping type of the silicon substrate is the same as the doping type of the third doped polycrystalline silicon layer.

[0105] like Figure 1 and Figure 5 As shown, in an optional embodiment, the solar cell further includes:

[0106] A third passivation layer 310, a second TCO layer 320, and a fourth passivation layer 330 are sequentially stacked on the second side of the silicon substrate 100 along the second direction D2.

[0107] In this case, the second direction D2 is opposite to the first direction D1.

[0108] The PID resistance effect can be further improved by forming the laminated passivation structure (i.e., the passivation layer, the TCO layer and the passivation layer laminated in sequence) on both sides of the silicon substrate.

[0109] In some embodiments, the material of the first passivation layer and the material of the second passivation layer respectively and independently include one or more of Al2O3, SiN x , SiON x , TiO x In some embodiments, the material of the second TCO layer includes one or more of fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, boron-doped zinc oxide, aluminum-gallium co-doped zinc oxide, aluminum-titanium co-doped zinc oxide, indium tin oxide, titanium oxide.

[0110] As shown in Figure 1 , in optional embodiments, the solar cell is a TOPCon solar cell; the TOPCon solar cell further includes:

[0111] a diffusion doped layer 470 located between the silicon substrate 100 and the first passivation layer 210;

[0112] a third passivation layer 310 and a fourth passivation layer 330 located on the second side of the silicon substrate 100 and laminated in sequence along the second direction D2; and

[0113] a first tunneling oxide layer 410 and a first doped polysilicon layer 420 located between the silicon substrate 100 and the third passivation layer 310 and laminated in sequence along the second direction D2;

[0114] wherein the doping type of the silicon substrate 100 is opposite to the doping type of the diffusion doped layer 470;

[0115] the doping type of the silicon substrate 100 is the same as the doping type of the first doped polysilicon layer 420.

[0116] The doping type of the silicon substrate is opposite to the doping type of the diffusion doped layer, and the silicon substrate and the diffusion doped layer form a PN junction.

[0117] As shown in Figure 1 , in optional embodiments, the first tunneling oxide layer 410 and the first doped polysilicon layer 420 in the TOPCon solar cell can be located only in the metal region, and the first tunneling oxide layer and the first doped polysilicon layer are not present on the non-metal region, and the third passivation layer 310 located in the non-metal region is in contact with the silicon substrate 100.

[0118] As shown in Figure 5 , in optional embodiments, the solar cell is a BC solar cell; the BC solar cell further includes:

[0119] A third passivation layer 310 and a fourth passivation layer 330 are sequentially stacked on the second surface of the silicon substrate 100 along the second direction D2; and

[0120] A first region 510 and a second region 520 are located on the second surface of the silicon substrate 100, and the first region 510 and the second region 520 are staggered and spaced apart from each other;

[0121] The first region 510 includes: a second tunneling oxide layer 430 and a second doped polysilicon layer 440, which are located between the silicon substrate 100 and the third passivation layer 310 and are sequentially stacked along the second direction D2.

[0122] The second region 520 includes: a third tunneling oxide layer 450 and a third doped polysilicon layer 460, which are located between the silicon substrate 100 and the third passivation layer 310 and are sequentially stacked along the second direction D2.

[0123] The doping type of the silicon substrate 100 is opposite to that of the second doped polycrystalline silicon layer 440;

[0124] The doping type of the silicon substrate 100 is the same as that of the third doped polycrystalline silicon layer 460.

[0125] The doping type of the silicon substrate is opposite to that of the second-doped polysilicon layer, forming a PN junction, with the second-doped polysilicon layer serving as the emitter. The doping type of the silicon substrate is the same as that of the third-doped polysilicon layer, with the third-doped polysilicon layer serving as the back surface field.

[0126] In some embodiments, the solar cell also includes electrodes.

[0127] like Figure 1 As shown, in some embodiments, the solar cell is a TOPCon solar cell, which includes a first electrode 610 located on a first surface of the silicon substrate 100 and a second electrode 620 located on a second surface of the silicon substrate 100.

[0128] like Figure 5 As shown, in some embodiments, the solar cell is a BC solar cell, which includes a first electrode 610 located on a first region 510 and a second electrode 620 located on a second region 520.

[0129] In some embodiments, the first electrode and the second electrode may each and independently include one or more of Au, Ag, Al, and Cu.

[0130] This application provides a method for preparing a solar cell according to any of the above embodiments, comprising:

[0131] Step S110: providing a silicon substrate, the silicon substrate comprising a first surface and a second surface arranged oppositely;

[0132] Step S120: sequentially stacking a first passivation layer, a first TCO layer and a second passivation layer on the first surface of the silicon substrate along a first direction.

[0133] In step S110, the silicon substrate can be an N-type silicon substrate or a P-type silicon substrate, which is not limited herein.

[0134] In step S120, the first passivation layer can be formed on the first surface of the silicon substrate by an atomic layer deposition (ALD) method or a plasma enhanced chemical vapor deposition (PECVD) method; the first TCO layer can be formed on the first passivation layer by a plasma enhanced chemical vapor deposition (PECVD) method, a physical vapor deposition (PVD) method or an atomic layer deposition (ALD) method; and the second passivation layer can be formed on the first TCO layer by an atomic layer deposition (ALD) method or a plasma enhanced chemical vapor deposition (PECVD) method.

[0135] In some embodiments, before step S120, the method for manufacturing the solar cell further comprises step S130: forming a diffusion doped layer on the silicon substrate.

[0136] In step S130, the diffusion doped layer can be formed on the silicon substrate by an ion implantation method or a plasma enhanced chemical vapor deposition (PECVD) method.

[0137] In some embodiments, before step S120, the method for manufacturing the solar cell further comprises step S140: forming a first tunneling oxide layer and a first doped polysilicon layer sequentially stacked along the first direction on the silicon substrate; wherein the doping type of the silicon substrate is opposite to the doping type of the diffusion doped layer; and the doping type of the silicon substrate is the same as the doping type of the first doped polysilicon layer.

[0138] In step S140, the first tunneling oxide layer can be formed on the silicon substrate by an atomic layer deposition (ALD) method or a chemical vapor deposition (CVD) method, and the material of the first tunneling oxide layer is SiO2; and the first doped polysilicon layer can be formed on the first tunneling oxide layer by a plasma enhanced chemical vapor deposition (PECVD) method or a physical vapor deposition (PVD) method.

[0139] In optional embodiments, after the first tunneling oxide layer and the first doped polysilicon layer are formed, step S140 further comprises: removing the first tunneling oxide layer and the first doped polysilicon layer in the non-metal region of the silicon wafer, and retaining the first tunneling oxide layer and the first doped polysilicon layer in the metal region.

[0140] In some embodiments, before step S120, the method for preparing a solar cell further comprises: step S150, forming a second tunneling oxide layer and a third tunneling oxide layer staggered and spaced apart from each other on the first surface of the silicon substrate; forming a second doped polysilicon layer on the second tunneling oxide layer, the second tunneling oxide layer and the second doped polysilicon layer together constituting a first region; forming a third doped polysilicon layer on the third tunneling oxide layer, the third tunneling oxide layer and the third doped polysilicon layer together constituting a second region.

[0141] wherein the doping type of the silicon substrate is opposite to the doping type of the second doped polysilicon layer; and the doping type of the silicon substrate is the same as the doping type of the third doped polysilicon layer.

[0142] In step S150, the second tunneling oxide layer and the third tunneling oxide layer can be formed on the silicon substrate by atomic layer deposition (ALD) or chemical vapor deposition (CVD), and the materials of the second tunneling oxide layer and the third tunneling oxide layer are both SiO2; the second doped polysilicon layer can be formed by plasma enhanced chemical vapor deposition (PECVD) or physical vapor deposition (PVD); and the third doped polysilicon layer can be formed by plasma enhanced chemical vapor deposition (PECVD) or physical vapor deposition (PVD).

[0143] The following specific embodiments further illustrate the present application, but should not be construed as limiting the present application. Modifications or replacements of the methods, steps or conditions of the present application, without departing from the spirit and essence of the present application, all belong to the scope of the present application.

[0144] Embodiment 1

[0145] As shown in FIG. 1, the specific structure of the solar cell of embodiment 1 includes: Figure 1

[0146] a silicon substrate 100, the silicon substrate 100 including a first surface and a second surface arranged opposite to each other, the silicon substrate 100 being an N-type silicon substrate;

[0147] a diffusion doped layer 470 (a P-type diffusion doped layer, the doping element being boron), a first passivation layer 210, a first TCO layer 220, a second passivation layer 230, and a first electrode 610, sequentially stacked on the first surface of the silicon substrate 100 along a first direction D1; wherein the first electrode 610 penetrates through the first passivation layer 210, the first TCO layer 220, and the second passivation layer 230 and contacts the diffusion doped layer 470;

[0148] ​The first tunneling oxide layer 410, the first doped polysilicon layer 420 (N-type doped polysilicon layer), the third passivation layer 310, the second TCO layer 320, the fourth passivation layer 330, and the second electrode 620 are sequentially stacked on the second surface of the silicon substrate 100 along the second direction D2; the second electrode 620 penetrates through the third passivation layer 310, the second TCO layer 320, and the fourth passivation layer 330 and is in contact with the first doped polysilicon layer 420.

[0149] The method for preparing the solar cell of Embodiment 1 comprises:

[0150] Step S201: providing a silicon substrate, the silicon substrate comprising oppositely arranged first and second surfaces, and the silicon substrate being an N-type silicon substrate;

[0151] Step S202: preparing a textured structure on the first surface of the silicon substrate;

[0152] Step S203: forming a diffusion doped layer on the first surface of the silicon substrate, the diffusion doped layer comprising boron as a doped element;

[0153] Step S204: sequentially diffusing a first tunneling oxide layer and a first doped polysilicon layer on the second surface of the silicon substrate, the first doped polysilicon layer comprising phosphorus as a doped element;

[0154] Step S205: removing the first tunneling oxide layer and the first doped polysilicon layer on the non-metallic region of the second surface of the silicon substrate by using a KOH and additive mixed solution;

[0155] Step S206: forming a first passivation layer with a thickness of 4 nm on the diffusion doped layer by using an ALD method with trimethylaluminum (TMA) and H2O, and forming a third passivation layer with a thickness of 4 nm on the surface of the first doped polysilicon layer and the exposed second surface of the silicon substrate, the first passivation layer and the third passivation layer being made of Al2O3;

[0156] Step S207: forming a first TCO layer with a thickness of 5 nm on the first passivation layer by using an ALD method with diethylzinc (DEZ), TMA, and H2O, the first TCO layer being made of aluminum-doped zinc oxide (5% of aluminum by mass);

[0157] Step S208: forming a second TCO layer with a thickness of 2 nm on the third passivation layer by using an ALD method with DEZ, TMA, titanium tetrachloride (TiCl4), and H2O, the second TCO layer being made of aluminum-titanium co-doped zinc oxide (8% of aluminum and titanium by mass in total);

[0158] Step S209: Using PECVD, a second passivation layer with a thickness of 90 nm is formed on the first TCO layer using silane and ammonia gas. A fourth passivation layer with a thickness of 90 nm is then formed on the second TCO layer. The materials of the second and fourth passivation layers are SiN. x ;

[0159] Step S210: Conductive paste is printed on the fourth passivation layer and the second passivation layer by screen printing, and then sintered to form a second electrode that penetrates the third passivation layer, the second TCO layer, and the fourth passivation layer and is in contact with the first doped polysilicon layer, and a first electrode that penetrates the first passivation layer, the first TCO layer, and the second passivation layer and is in contact with the diffusion doped layer.

[0160] Example 2

[0161] like Figure 2 As shown, the solar cell of Example 2 has a similar structure to the solar cell of Example 1, except that the solar cell of Example 2 does not have a second TCO layer.

[0162] The solar cell of Example 2 was prepared using a similar method to that of Example 1, except that the preparation method of the solar cell of Example 2 did not include step S208; and

[0163] Step S209 involves using PECVD to form a second passivation layer with a thickness of 95 nm on the first TCO layer using silane and ammonia, and a fourth passivation layer with a thickness of 90 nm on the third passivation layer. The materials of the second and fourth passivation layers are SiN. x ;

[0164] Step S210 is as follows: conductive paste is printed on the fourth passivation layer and the second passivation layer by screen printing, and then sintered to form a second electrode that penetrates the third passivation layer and the fourth passivation layer and is in contact with the first doped polysilicon layer, and a first electrode that penetrates the first passivation layer, the first TCO layer and the second passivation layer and is in contact with the diffusion doped layer.

[0165] Example 3

[0166] like Figure 3 As shown, the solar cell of Example 3 has a similar structure to the solar cell of Example 1, except that the solar cell of Example 3 does not have a first TCO layer.

[0167] The solar cell of Example 3 was prepared using a similar method to that of Example 1, except that the preparation method of the solar cell of Example 3 did not include step S207; and

[0168] Step S209: Using PECVD, a second passivation layer with a thickness of 90 nm is formed on the first passivation layer using silane and ammonia, and a fourth passivation layer with a thickness of 95 nm is formed on the second TCO layer. The materials of the second and fourth passivation layers are SiN. x ;

[0169] Step S210: Conductive paste is printed on the fourth passivation layer and the second passivation layer by screen printing, and then sintered to form a second electrode that penetrates the third passivation layer, the second TCO layer, and the fourth passivation layer and is in contact with the first doped polysilicon layer, and a first electrode that penetrates the first passivation layer and the second passivation layer and is in contact with the diffused doped layer.

[0170] Example 4

[0171] like Figure 4 As shown, the solar cell of Example 4 has a similar structure to the solar cell of Example 1. The only difference is that the first TCO layer 220 in the solar cell of Example 4 includes a first sub-TCO layer 221, a second sub-TCO layer 222, and a third sub-TCO layer 223 stacked along the first direction D1.

[0172] The solar cell of Example 4 was prepared using a similar preparation method to Example 1, except that in the preparation method of the solar cell of Example 4, step S207 is as follows: ALD method is used to form a first sub-TCO layer with a thickness of 3 nm on the first passivation layer using DEZ, TMA, titanium tetrachloride (TiCl4), and H2O. The material of the first sub-TCO layer is aluminum-titanium co-doped zinc oxide (total mass percentage of aluminum and titanium is 4%). ALD method is also used to form a second sub-TCO layer with a thickness of 4 nm on the first sub-TCO layer using DEZ, trimethylgallium (TMGa), and H2O. The material of the second sub-TCO layer is gallium-doped zinc oxide (mass percentage of gallium is 2.5%). ALD method is then used to form a third sub-TCO layer with a thickness of 3 nm on the second sub-TCO layer using DEZ, TMA, and H2O. The material of the third sub-TCO layer is aluminum-doped zinc oxide (mass percentage of aluminum is 3%). The first, second, and third sub-TCO layers together constitute the first TCO layer.

[0173] Example 5

[0174] The solar cell of Example 5 has the same structure as the solar cell of Example 1.

[0175] The solar cell of Example 5 was prepared using a similar preparation method as in Example 1, except that in the preparation method of the solar cell of Example 5, step S207 is as follows: using the ALD method, diethylzinc (DEZ), TMA and H2O are used to form a first TCO layer with a thickness of 7nm on the first passivation layer. The material of the first TCO layer is aluminum-doped zinc oxide (2% by mass of aluminum).

[0176] Example 6

[0177] The solar cell of Example 6 has the same structure as the solar cell of Example 1.

[0178] The solar cell of Example 6 was prepared using a similar preparation method as in Example 1, except that in the preparation method of the solar cell of Example 6, step S207 is as follows: using the ALD method, tetrabutyltin (TBTO), trimethylantimony (TMA) and H2O are used to form a first TCO layer with a thickness of 3nm on the first passivation layer. The material of the first TCO layer is antimony-doped tin oxide (antimony mass percentage is 5%).

[0179] Example 7

[0180] like Figure 5 As shown, the specific structure of the solar cell in Example 7 includes:

[0181] The silicon substrate 100 includes a first surface and a second surface disposed opposite to each other, and the silicon substrate 100 is an N-type silicon substrate;

[0182] A first passivation layer 210, a first TCO layer 220, and a second passivation layer 230 are sequentially stacked on the first surface of the silicon substrate 100 along the first direction D1.

[0183] Located on the second surface of the silicon substrate 100, there are staggered and spaced-apart first regions 510 and second regions 520. The first region 510 includes a second tunneling oxide layer 430 and a second doped polysilicon layer 440 (P-type doped polysilicon layer) stacked sequentially between the silicon substrate 100 and the third passivation layer 310 along the second direction D2. The second region 520 includes a third tunneling oxide layer 450 and a third doped polysilicon layer 460 (N-type doped polysilicon layer) stacked sequentially between the silicon substrate 100 and the third passivation layer 310 along the second direction D2.

[0184] A third passivation layer 310, a second TCO layer 320, and a fourth passivation layer 330 are sequentially stacked on the second doped polysilicon layer 440 and the third doped polysilicon layer 460 along the second direction D2.

[0185] a first electrode 610 penetrating through the third passivation layer 310, the second TCO layer 320 and the fourth passivation layer 330 and being in contact with the second doped polysilicon layer 440;

[0186] a second electrode 620 penetrating through the third passivation layer 310, the second TCO layer 320 and the fourth passivation layer 330 and being in contact with the third doped polysilicon layer 460.

[0187] The method for preparing the solar cell of Embodiment 7 comprises:

[0188] Step S301: providing a silicon substrate, the silicon substrate comprising oppositely arranged first and second surfaces, the silicon substrate being an N-type silicon substrate;

[0189] Step S302: forming second and third tunnel oxide layers on the second surface of the silicon substrate by using an ALD method, the second and third tunnel oxide layers being staggered and spaced apart;

[0190] Step S303: forming a second doped polysilicon layer on the second tunnel oxide layer by using a PECVD method, the second doped polysilicon layer being a P-type doped polysilicon layer; the second tunnel oxide layer and the second doped polysilicon layer together constituting a first region;

[0191] forming a third doped polysilicon layer on the third tunnel oxide layer by using a PECVD method, the third doped polysilicon layer being an N-type doped polysilicon layer; the third tunnel oxide layer and the third doped polysilicon layer together constituting a second region;

[0192] Step S304: forming a first passivation layer with a thickness of 4 nm on the first surface of the silicon substrate by using an ALD method, the material of the first passivation layer being Al2O3;

[0193] Step S305: forming a third passivation layer with a thickness of 5 nm on the second and third doped polysilicon layers by using an ALD method, the material of the third passivation layer being Al2O3;

[0194] Step S306: forming a first TCO layer with a thickness of 5 nm on the first passivation layer by using an ALD method, the material of the first TCO layer being aluminum-doped zinc oxide (aluminum mass percentage being 5%);

[0195] Step S307: forming a second TCO layer with a thickness of 2 nm on the third passivation layer by using an ALD method, the material of the second TCO layer being aluminum-titanium co-doped zinc oxide (total mass percentage of aluminum and titanium being 8%);

[0196] Step S308: Using PECVD, a second passivation layer with a thickness of 95 nm is formed on the first TCO layer using silane and ammonia. The material of the second passivation layer is SiN. x ;

[0197] Step S309: Using PECVD, a fourth passivation layer with a thickness of 105 nm is formed on the second TCO layer using silane and ammonia. The material of the fourth passivation layer is SiN. x ;

[0198] Step S310: Conductive paste is printed on the fourth passivation layer corresponding to the first region using screen printing, and then sintered to form a first electrode that penetrates the third passivation layer, the second TCO layer and the fourth passivation layer and is in contact with the second doped polysilicon layer.

[0199] Conductive paste is printed on the fourth passivation layer corresponding to the second region using screen printing, and then sintered to form a second electrode that penetrates the third passivation layer, the second TCO layer, the fourth passivation layer, and is in contact with the third doped polysilicon layer.

[0200] Example 8

[0201] like Figure 6 As shown, the solar cell of Example 8 has a similar structure to the solar cell of Example 7, except that the solar cell of Example 8 does not have a second TCO layer.

[0202] The solar cell of Example 8 was prepared using a similar method to that of Example 7, except that the preparation method of the solar cell of Example 8 did not include step S307, and step S309 was: using PECVD to form a fourth passivation layer with a thickness of 95 nm on the third passivation layer with silane and ammonia gas, the material of the fourth passivation layer being SiN. x .

[0203] Example 9

[0204] like Figure 7 As shown, the solar cell of Example 9 has a similar structure to the solar cell of Example 7, except that the solar cell of Example 9 does not have a first TCO layer.

[0205] The solar cell of Example 9 was prepared using a similar method to that of Example 7, except that the preparation method of the solar cell of Example 9 did not include step S306, and step S308 was: using PECVD to form a second passivation layer with a thickness of 95 nm on the first passivation layer using silane and ammonia gas, the material of the second passivation layer being SiN. x .

[0206] Example 10

[0207] As shown in FIG. 10, the solar cell of Example 10 has a structure similar to that of the solar cell of Example 7, except that the first TCO layer 220 in the solar cell of Example 10 includes a first sub-TCO layer 221, a second sub-TCO layer 222, and a third sub-TCO layer 223 stacked along the first direction D1. Figure 8 The solar cell of Example 10 is prepared by using a preparation method similar to that of Example 7, except that in the preparation method of the solar cell of Example 10, step S306 is: using the ALD method, DEZ, TMA, titanium tetrachloride (TiCl4), and H2O are used to form a first sub-TCO layer with a thickness of 4 nm on the first passivation layer, and the material of the first sub-TCO layer is aluminum and titanium co-doped zinc oxide (the total mass percentage of aluminum and titanium is 4%); using the ALD method, DEZ, trimethyl gallium (TMGa), and H2O are used to form a second sub-TCO layer with a thickness of 6 nm on the first sub-TCO layer, and the material of the second sub-TCO layer is gallium-doped zinc oxide (the mass percentage of gallium is 2%); using the ALD method, DEZ, TMA, and H2O are used to form a third sub-TCO layer with a thickness of 2 nm on the second sub-TCO layer, and the material of the third sub-TCO layer is aluminum-doped zinc oxide (the mass percentage of aluminum is 3%); and the first sub-TCO layer, the second sub-TCO layer, and the third sub-TCO layer together constitute the first TCO layer.

[0208] In order to more clearly illustrate the technical effects of the embodiments of the present application, the specific structures and preparation methods of the solar cells of Comparative Example 1 and Comparative Example 2 are also pointed out.

[0209] Comparative Example 1

[0210] The solar cell of Comparative Example 1 has a structure similar to that of the solar cell of Example 1, except that the solar cell of Comparative Example 1 does not have a first TCO layer and a second TCO layer.

[0211] The solar cell of Comparative Example 1 is prepared by using a preparation method similar to that of Example 1, except that the preparation method of the solar cell of Comparative Example 1 does not include steps S207 and S208, and step S209 is: using the PECVD method, silane and ammonia are used to form a second passivation layer with a thickness of 90 nm on the first passivation layer, and silane and ammonia are used to form a fourth passivation layer with a thickness of 90 nm on the third passivation layer, and the materials of the second passivation layer and the fourth passivation layer are SiN x .

[0212] Comparative Example 2

[0213] The solar cell of Comparative Example 2 has a structure similar to that of the solar cell of Example 2, except that the solar cell of Comparative Example 2 does not have a first TCO layer and a second TCO layer.

[0214] The solar cell of Comparative Example 2 is similar in structure to the solar cell of Example 7, except that the solar cell of Comparative Example 2 does not have the first TCO layer and the second TCO layer.

[0215] The solar cell of Comparative Example 2 is prepared by using a preparation method similar to that of Example 7, except that the preparation method of the solar cell of Comparative Example 2 does not include steps S306 and S307, and step S308 is: forming a second passivation layer with a thickness of 100 nm on the first passivation layer by using a PECVD method, and the material of the second passivation layer is SiN x ; and step S309 is: forming a fourth passivation layer with a thickness of 95 nm on the third passivation layer by using a PECVD method, and the material of the fourth passivation layer is SiN x .

[0216] The solar cells in Examples 1 to 10 and Comparative Examples 1 to 2 are also made into corresponding photovoltaic modules, and the power attenuation values ΔP are obtained by performing PID96 decay tests. The related test results are shown in Table 1.

[0217] Table 1

[0218]

[0219] Table 1 (continued)

[0220]

[0221] As can be seen from the data in Table 1, compared with Comparative Examples 1 and 2, the photovoltaic modules made of the solar cells in Examples 1 to 10 have lower power attenuation values, and the power attenuation values of the modules after PID96h are less than 5%, which meets the IEC (International Electrotechnical Commission) standard. This shows that, compared with conventional cell modules, the photovoltaic modules made of the solar cells in Examples 1 to 10 have good anti-PID effect.

[0222] In summary, the solar cell of the present application forms a laminated passivation structure by sequentially stacking a first passivation layer, a first TCO (transparent conductive oxide) layer and a second passivation layer on the silicon substrate. The TCO layer is compact in texture, which can effectively block alkali metal ions from entering the interior of the silicon substrate. Moreover, the TCO layer has good conductivity, serving as a transmission channel for electric charges, and can quickly conduct the electric charges accumulated on the surface of the cell, thereby effectively solving the problem of potential induced degradation (PID) and having good PID resistance. In addition, the TCO layer is located between the two passivation layers, so that the TCO layer is not directly in contact with the silicon substrate, which can avoid the increase of interface defect state density due to lattice mismatch. The second passivation layer is provided to encapsulate and protect the TCO layer, avoiding the damage of the TCO layer by water vapor and other pollutants. In summary, the solar cell of the present application can effectively solve the PID problem and has good PID resistance.

[0223] It should be noted that the terms "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are merely intended to facilitate the description of the present application and simplify the description, and are not intended to indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. The orientation terms "inner" and "outer" refer to the inner and outer of the profile of each component itself. For example, if the devices in the drawings are inverted, the devices described as "above" or "on" other devices or structures will be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The devices can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0224] It should be noted that the terms "first", "second", and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a particular order or sequence. It should be understood that the terms thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0225] It is also need to be explained that, in the present application, "one embodiment", "another embodiment", "embodiment" and the like refer to the specific features, structures or characteristics described in connection with the embodiment are included in at least one embodiment described in the general description of the present application. The same expression appears in several places in the specification does not necessarily refer to the same embodiment. Further, when a specific feature, structure or characteristic is described in connection with any embodiment, it is claimed that the implementation of such feature, structure or characteristic in connection with other embodiments also falls within the scope of the present application.

[0226] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0227] It is also need to be explained that, the above is only the preferred embodiment of the present application, and does not limit the patent protection scope of the present application, and any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A solar cell having a good effect against PID, characterized by comprising: Comprise: a silicon substrate comprising a first surface and a second surface arranged oppositely; a first passivation layer, a first TCO layer, and a second passivation layer arranged sequentially in the first surface of the silicon substrate and along a first direction; the first TCO layer comprises a first sub-TCO layer, a second sub-TCO layer, and a third sub-TCO layer arranged sequentially along the first direction; wherein the refractive index of the first sub-TCO layer is greater than the refractive index of the second sub-TCO layer; the refractive index of the second sub-TCO layer is greater than the refractive index of the third sub-TCO layer; the material of the first sub-TCO layer is aluminum and titanium co-doped zinc oxide, wherein the total mass percentage of aluminum and titanium elements is 0.1-5%; the material of the second sub-TCO layer is gallium-doped zinc oxide, wherein the mass percentage of gallium element is 0.1-3%; the material of the third sub-TCO layer is aluminum-doped zinc oxide, wherein the mass percentage of aluminum element is 0.1-5%.

2. The solar cell according to claim 1, characterized in that, The refractive index of the first sub-TCO layer is 1.9-2.2, the refractive index of the second sub-TCO layer is 1.8-2.1, and the refractive index of the third sub-TCO layer is 1.7-2.

0.

3. The solar cell of claim 1, wherein The material of the first passivation layer and the material of the second passivation layer each and independently comprise one or more of AI2O3, SiN x , SiON x , TiO x .

4. The solar cell of claim 1, wherein The material of the first passivation layer comprises one or more of AI2O3, SiN x , SiON x , TiO x . The material of the second passivation layer comprises one or both of SiN x , SiON x .

5. The solar cell of claim 1, wherein The sheet resistance of the first TCO layer is 1 Ω / sq - 10 6 Ω / sq.

6. The solar cell according to any one of claims 1-5, characterized in that: the solar cell is a TOPCon solar cell; the TOPCon solar cell further comprises: a first tunneling oxide layer and a first doped polysilicon layer arranged sequentially between the silicon substrate and the first passivation layer and along the first direction; the doping type of the silicon substrate is the same as the doping type of the first doped polysilicon layer; or the solar cell is a BC solar cell; the BC solar cell further comprises a first region and a second region on the first surface of the silicon substrate, the first region and the second region are staggered and arranged apart from each other; the first region comprises: a second tunneling oxide layer and a second doped polysilicon layer arranged sequentially between the silicon substrate and the first passivation layer and along the first direction; the second region comprises: a third tunneling oxide layer and a third doped polysilicon layer arranged sequentially between the silicon substrate and the first passivation layer and along the first direction; the doping type of the silicon substrate is opposite to the doping type of the second doped polysilicon layer; the doping type of the silicon substrate is the same as the doping type of the third doped polysilicon layer.

7. The solar cell according to any one of claims 1 to 5, wherein Further comprise: a third passivation layer, a second TCO layer, and a fourth passivation layer arranged sequentially in the second surface of the silicon substrate and along a second direction; wherein the second direction is opposite to the first direction.

8. The solar cell according to any one of claims 1 to 5, characterized in that, the solar cell is a TOPCon solar cell; the TOPCon solar cell further comprises: a diffusion doped layer between the silicon substrate and the first passivation layer; a third passivation layer and a fourth passivation layer arranged sequentially in the second surface of the silicon substrate and along a second direction; and a first tunneling oxide layer and a first doped polysilicon layer arranged sequentially between the silicon substrate and the third passivation layer and along the second direction; wherein the doping type of the silicon substrate is opposite to the doping type of the diffusion doped layer; The doping type of the silicon substrate is the same as the doping type of the first doped polysilicon layer.

9. The solar cell according to any one of claims 1 to 5, characterized in that, The solar cell is a BC solar cell. The BC solar cell further comprises: a third passivation layer and a fourth passivation layer which are sequentially stacked along the second direction on the second surface of the silicon substrate; and a first region and a second region which are arranged alternately and spaced apart from each other on the second surface of the silicon substrate; The first region comprises a second tunneling oxide layer and a second doped polysilicon layer which are sequentially stacked along the second direction between the silicon substrate and the third passivation layer. The second region comprises a third tunneling oxide layer and a third doped polysilicon layer which are sequentially stacked along the second direction between the silicon substrate and the third passivation layer. The doping type of the silicon substrate is opposite to the doping type of the second doped polysilicon layer. The doping type of the silicon substrate is the same as the doping type of the third doped polysilicon layer.

10. A method of producing a solar cell as claimed in any one of claims 1 to 9, characterized in that, comprises: providing a silicon substrate comprising a first surface and a second surface arranged oppositely; a first passivation layer, a first TCO layer and a second passivation layer which are sequentially stacked along the first direction on the first surface of the silicon substrate.

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