Photovoltaic cell, photovoltaic cell assembly and electric equipment

Abstract

The utility model relates to the technical field of cells, and provides a photovoltaic cell, a photovoltaic cell assembly and electric equipment, the photovoltaic cell comprises a substrate layer, a passivation contact layer and a heavily doped region; the passivation contact layer and the substrate layer are stacked; the passivation contact layer comprises an N-type passivation contact layer and a P-type passivation contact layer which are arranged at an interval; the heavily doped region is located in the substrate layer; the heavily doped region comprises at least one of an N-type heavily doped region and a P-type heavily doped region, the projection of the N-type heavily doped region on the passivation contact layer along the thickness direction of the photovoltaic cell is at least partially overlapped with the N-type passivation contact layer, and / or the projection of the P-type heavily doped region on the passivation contact layer along the thickness direction of the photovoltaic cell is at least partially overlapped with the N-type passivation contact layer; and the projection of the P-type heavily doped region on the passivation contact layer along the thickness direction of the photovoltaic cell is at least partially overlapped with the P-type passivation contact layer. According to the photovoltaic cell provided by the embodiment of the invention, the selective separation process of electrons and holes can be completed in advance, and the recombination probability of carriers in the transmission process is reduced.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a photovoltaic cell, a photovoltaic cell module, and an electrical device. Background Technology

[0002] A solar cell is a device that directly converts light energy into electrical energy through the photoelectric effect or photochemical effect.

[0003] Currently, to further improve the conversion efficiency of crystalline silicon solar cells, common crystalline silicon solar cells place all metal grids on the back side, completely releasing the optical shading area on the front side, thereby improving the utilization rate of sunlight. However, since all the grids are on the back side, the electron-hole pairs generated by the cell absorbing photons need to diffuse to the back interface for electron-hole separation to achieve selective separation and collection. This process requires electrons or holes to undergo a relatively long diffusion distance and time, during which carrier recombination is likely to occur. Utility Model Content

[0004] This application provides a photovoltaic cell, a photovoltaic cell module, and an electrical device that can complete the selective separation process of electrons and holes in advance, reducing the probability of carrier recombination during transmission.

[0005] A first aspect of this application provides a photovoltaic cell, comprising: a substrate layer;

[0006] A passivation contact layer; the passivation contact layer is stacked with the substrate layer;

[0007] The passivation contact layer includes: an N-type passivation contact layer and a P-type passivation contact layer spaced apart;

[0008] and heavily doped regions; the heavily doped regions are located within the substrate layer;

[0009] The heavily doped region includes at least one of an N-type heavily doped region and a P-type heavily doped region, wherein the projection of the N-type heavily doped region onto the passivation contact layer along the thickness direction of the photovoltaic cell at least partially overlaps with the N-type passivation contact layer, and / or, the projection of the P-type heavily doped region onto the passivation contact layer along the thickness direction of the photovoltaic cell at least partially overlaps with the P-type passivation contact layer.

[0010] This application embodiment achieves selective separation of charge carriers within the substrate by setting heavily doped regions within the substrate. Specifically, the heavily doped regions include N-type heavily doped regions, whose projections along the thickness direction of the photovoltaic cell onto the passivation contact layer at least partially overlap with the N-type passivation contact layer; or, the heavily doped regions include P-type heavily doped regions, whose projections along the thickness direction of the photovoltaic cell onto the passivation contact layer at least partially overlap with the P-type passivation contact layer; or, the heavily doped regions include both N-type and P-type heavily doped regions, where the projections of the N-type heavily doped regions along the thickness direction of the photovoltaic cell onto the passivation contact layer at least partially overlap with the N-type passivation contact layer, and the projections of the P-type heavily doped regions along the thickness direction of the photovoltaic cell onto the passivation contact layer at least partially overlap with the P-type passivation contact layer. This enables selective separation of charge carriers within the substrate. Extending the P-type or N-type heavily doped regions deep into the substrate facilitates the earlier completion of the selective separation process of electrons and holes, thereby reducing the probability of recombination of charge carriers during transport within the substrate.

[0011] In one possible implementation, the heavily doped region is in contact with the side of the substrate layer near the passivation contact layer.

[0012] In one possible implementation, the projection of the N-type heavily doped region onto the passivation contact layer along the thickness direction of the photovoltaic cell is located within the N-type passivation contact layer, and / or, the projection of the P-type heavily doped region onto the passivation contact layer along the thickness direction of the photovoltaic cell is located within the P-type passivation contact layer.

[0013] In one possible implementation, the passivation contact layer further includes an insulating portion located between the N-type passivation contact layer and the P-type passivation contact layer.

[0014] In one possible implementation, the width of the insulating portion is greater than 0 and less than or equal to 100 μm.

[0015] In one possible implementation, the crystallinity of the insulating portion is greater than that of the N-type passivation contact layer;

[0016] And / or, the crystallinity of the insulating portion is greater than the crystallinity of the P-type passivation contact layer.

[0017] The crystallinity of the N-type passivated contact layer is 85%-90%; and / or,

[0018] The crystallinity of the P-type passivation contact layer is 85%-90%; and / or,

[0019] The crystallinity of the insulating part is higher than 90%.

[0020] In one possible implementation, the N-type heavily doped region has a dimension of less than or equal to 5 μm in the thickness direction of the photovoltaic cell.

[0021] In one possible implementation, the P-type heavily doped region has a dimension of less than or equal to 3 μm in the thickness direction of the photovoltaic cell.

[0022] In one possible implementation, the passivation contact layer has a dimension of 100nm-300nm in the thickness direction of the photovoltaic cell.

[0023] In one possible implementation, it further includes: a first passivation layer; the first passivation layer is located between the substrate layer and the passivation contact layer.

[0024] In one possible implementation, the first passivation layer has a dimension of less than or equal to 2 nm in the thickness direction of the photovoltaic cell.

[0025] In one possible implementation, it further includes: a second passivation layer; the second passivation layer is located on the side of the substrate layer opposite to the passivation contact layer.

[0026] In one possible implementation, the second passivation layer has a dimension of less than or equal to 15 nm in the thickness direction of the photovoltaic cell.

[0027] In one possible implementation, it further includes: a first anti-reflective layer; the first anti-reflective layer is located on the side of the second passivation layer opposite to the substrate layer.

[0028] In one possible implementation, the first antireflective layer has a dimension of 50nm-150nm in the thickness direction of the photovoltaic cell.

[0029] In one possible implementation, a second anti-reflective layer is also included; the second anti-reflective layer is located on the side of the passivated contact layer opposite to the first passivation layer.

[0030] In one possible implementation, the second antireflective layer has a dimension of 50nm-150nm in the thickness direction of the photovoltaic cell.

[0031] In one possible implementation, it further includes: multiple electrodes; the N-type passivation contact layer and the P-type passivation contact layer are each independently connected to the electrodes.

[0032] In one possible implementation, the number of N-type passivation contact layers is multiple, and the number of P-type passivation contact layers is multiple;

[0033] Multiple N-type passivated contact layers and multiple P-type passivated contact layers are arranged alternately at intervals.

[0034] A second aspect of this application provides a photovoltaic cell module, comprising at least a housing and any of the photovoltaic cells described above; the photovoltaic cells are located inside the housing.

[0035] The embodiments of this application can improve the performance of photovoltaic modules by setting the aforementioned photovoltaic cells in the photovoltaic cell module.

[0036] A third aspect of this application provides an electrical device comprising at least any of the photovoltaic cells or photovoltaic cell modules described above.

[0037] The embodiments of this application can improve the performance of electrical equipment by setting the above-mentioned photovoltaic cells or photovoltaic cell modules in the electrical equipment. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the structure of a photovoltaic cell in the prior art;

[0040] Figure 2 This is a schematic diagram of a photovoltaic cell provided in an embodiment of this application;

[0041] Figure 3 This is a schematic diagram of another structure of the photovoltaic cell provided in an embodiment of this application;

[0042] Figure 4 This is another structural schematic diagram of a photovoltaic cell provided in an embodiment of this application.

[0043] Figure label:

[0044] 100-Photovoltaic cells;

[0045] 110 - Substrate layer;

[0046] 120 - Passivation contact layer;

[0047] 121-N-type passivation contact layer; 122-P-type passivation contact layer; 123-insulation portion;

[0048] 130-Heavy doped region;

[0049] 131-N-type heavily doped region; 132-P-type heavily doped region;

[0050] 140 - First passivation layer;

[0051] 150 - Second passivation layer;

[0052] 160 - First anti-reflective layer;

[0053] 170 - Second anti-reflective layer;

[0054] 180-Electrode. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0056] In response to the increasingly serious energy crisis and environmental pollution, the development of clean solar energy has received widespread attention. As one of the ways to utilize solar energy, solar cells have naturally become a hot topic in the market.

[0057] Currently, crystalline silicon solar cells have the highest market share in the photovoltaic market. Among them, tunnel oxide passivated contact (TOPCon) solar cells are a new type of passivated contact solar cells based on the selective carrier principle. The photovoltaic cell is an N-type silicon substrate cell. An ultra-thin layer of silicon oxide is prepared on the back of the cell, and then a layer of doped polycrystalline silicon is deposited. The two together form a passivated contact structure, which effectively reduces surface recombination and metal contact recombination.

[0058] To further improve the conversion efficiency of solar cells, in recent years, back-contact interdigitated cells based on TOPCon technology have been considered an important next-generation efficiency improvement strategy. This structure places all metal grids on the back of the cell, helping to completely free up the optical shading area on the front, improving the utilization of sunlight, and thus achieving an absolute efficiency improvement of 0.5%-1%.

[0059] Figure 1 This is a schematic diagram of the structure of a photovoltaic cell in the prior art. See related technologies. Figure 1The crystalline silicon solar cell shown places all metal gates on the back side. However, because all the gates are on the back side, the electron-hole pairs generated by the cell absorbing photons need to diffuse to the back interface for electron and hole separation to achieve selective collection. This process requires electrons or holes to undergo a relatively long diffusion distance and time, during which carrier recombination is likely to occur.

[0060] To address the aforementioned issues, this application provides a novel photovoltaic cell. By setting a heavily doped region within the substrate, specifically, the heavily doped region includes an N-type heavily doped region whose projection along the thickness direction of the photovoltaic cell onto the passivation contact layer at least partially overlaps with the N-type passivation contact layer; or, the heavily doped region includes a P-type heavily doped region whose projection along the thickness direction of the photovoltaic cell onto the passivation contact layer at least partially overlaps with the P-type passivation contact layer; or, the heavily doped region includes both N-type and P-type heavily doped regions, where the projection of the N-type heavily doped region along the thickness direction of the photovoltaic cell onto the passivation contact layer at least partially overlaps with the N-type passivation contact layer, and the projection of the P-type heavily doped region along the thickness direction of the photovoltaic cell onto the passivation contact layer at least partially overlaps with the P-type passivation contact layer. This enables selective separation of charge carriers within the substrate layer. Extending the P-type or N-type heavily doped region deep into the substrate facilitates the earlier completion of the selective separation process of electrons and holes, thereby reducing the probability of recombination of charge carriers during transport within the substrate layer.

[0061] The photovoltaic cell, photovoltaic cell module, and electrical equipment having the photovoltaic cell provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0062] Figure 2 This is a schematic diagram of a photovoltaic cell provided in an embodiment of this application. Figure 3 This is a schematic diagram of another structure of the photovoltaic cell provided in an embodiment of this application. Figure 4 This is another structural schematic diagram of a photovoltaic cell provided in an embodiment of this application.

[0063] Reference Figures 2 to 4 As shown, this application embodiment provides a photovoltaic cell 100, which may include a substrate layer 110, a passivation contact layer 120 and a heavily doped region 130, wherein the passivation contact layer 120 and the substrate layer 110 are stacked.

[0064] It is understood that, in the embodiments of this application, the substrate layer 110 may be made of silicon.

[0065] Specifically, in this embodiment, the passivation contact layer 120 may include an N-type passivation contact layer 121 and a P-type passivation contact layer 122 spaced apart, and the heavily doped region 130 may be located within the substrate layer 110. It should be noted that the concentration of the heavily doped region 130 is higher than the concentration of the substrate layer 110.

[0066] In this embodiment, the heavily doped region 130 may include at least one of an N-type heavily doped region 131 and a P-type heavily doped region 132, wherein the projection of the N-type heavily doped region 131 on the passivation contact layer 120 along the thickness direction of the photovoltaic cell 100 at least partially overlaps with the N-type passivation contact layer 121, and the projection of the P-type heavily doped region 132 on the passivation contact layer 120 along the thickness direction of the photovoltaic cell 100 at least partially overlaps with the P-type passivation contact layer 122.

[0067] In this embodiment, the heavily doped region 130 may be configured in several ways, including but not limited to the following:

[0068] One possible implementation is as follows: Figure 2 As shown, the heavily doped region 130 includes an N-type heavily doped region 131, and the projection of the N-type heavily doped region 131 along the thickness direction of the photovoltaic cell 100 onto the passivation contact layer 120 at least partially overlaps with the N-type passivation contact layer 121.

[0069] Another possible implementation is: Figure 3 As shown, the heavily doped region 130 includes a P-type heavily doped region 132, and the projection of the P-type heavily doped region 132 along the thickness direction of the photovoltaic cell 100 onto the passivation contact layer 120 at least partially overlaps with the P-type passivation contact layer 122.

[0070] Another possible implementation is: Figure 4 As shown, the heavily doped region 130 includes an N-type heavily doped region 131 and a P-type heavily doped region 132. The projection of the N-type heavily doped region 131 onto the passivation contact layer 120 along the thickness direction of the photovoltaic cell 100 at least partially overlaps with the N-type passivation contact layer 121. The projection of the P-type heavily doped region 132 onto the passivation contact layer 120 along the thickness direction of the photovoltaic cell 100 at least partially overlaps with the P-type passivation contact layer 122.

[0071] This embodiment of the application, by providing a heavily doped region 130 within the substrate region, enables selective separation of charge carriers within the substrate layer 110. Extending the P-type heavily doped region 132 or the N-type heavily doped region 131 deep into the substrate facilitates the earlier completion of the selective separation process between electrons and holes, thereby reducing the probability of recombination during carrier transport within the substrate layer 110. Furthermore, it expands the effective area for selective separation of electrons and holes, thereby increasing the carrier separation capability.

[0072] It is understandable that, such as Figure 4 As shown in the embodiment of this application, the heavily doped region 130 is in contact with the side of the substrate layer 110 near the passivation contact layer 120.

[0073] In this embodiment, the projection of the N-type heavily doped region 131 along the thickness direction of the photovoltaic cell 100 onto the passivation contact layer 120 can be located within the N-type passivation contact layer 121.

[0074] Similarly, the projection of the P-type heavily doped region 132 along the thickness direction of the photovoltaic cell 100 onto the passivation contact layer 120 can be located within the P-type passivation contact layer 122.

[0075] In this embodiment, the passivation contact layer 120 may further include an insulating portion 123, wherein the insulating portion 123 is located between the N-type passivation contact layer 121 and the P-type passivation contact layer 122. The insulating portion 123 serves as an insulator. Furthermore, filling the space between the N-type passivation contact layer 121 and the P-type passivation contact layer 122 with the insulating portion 123 can enhance the mechanical properties of the passivation contact layer 120.

[0076] It should be noted that the material used for the insulating part 123 can be intrinsic silicon or the like. This application does not limit this, nor is it limited to the above example.

[0077] In this embodiment, the crystallinity of the insulating portion 123 can be greater than that of the N-type passivation contact layer 121. Similarly, in this embodiment, the crystallinity of the insulating portion 123 can be greater than that of the P-type passivation contact layer 122.

[0078] It is understood that the crystallinity of the N-type passivation contact layer 121 can be 85%-90%, for example, the crystallinity of the N-type passivation contact layer 121 can be 85%, 85%, 85%, 85%, 85%, 90% or any two of these ranges, and the crystallinity of the P-type passivation contact layer 122 can be 85%-90%, for example, the crystallinity of the P-type passivation contact layer 122 can be 85%, 85%, 85%, 85%, 85%, 90% or any two of these ranges.

[0079] The crystallization rate of the insulating portion 123 can be higher than 90%. For example, the crystallization rate of the insulating portion 123 can be a range of 91%, 92%, 93%, 94%, 95% or any two of them. The embodiments of this application do not limit this, nor are they limited to the above examples.

[0080] By designing the crystallinity of the insulating portion 123 to be greater than that of the N-type passivation contact layer 121 and the P-type passivation contact layer 122, the optical transmittance of the passivation contact layer 120 can be enhanced.

[0081] In this embodiment, the width of the insulating portion 123 can be greater than 0 and less than or equal to 100 μm. By designing the width of the insulating portion 123, lateral diffusion between boron in the P-type passivation contact layer 122 and phosphorus in the N-type passivation contact layer 121 can be avoided, thereby preventing a decrease in the conductivity of the insulating portion 123. Furthermore, if the width of the insulating portion 123 is too wide, it can easily affect the area of ​​the N-type passivation contact layer 121 and the P-type passivation contact layer 122, thereby easily reducing the effective collection of charge carriers.

[0082] For example, the width of the insulating portion 123 can be a range of 100um, 95um, 90um, 85um, 80um, 75um, 70um or any two of these. The embodiments of this application do not limit this range, nor are they limited to the above examples.

[0083] It should be noted that the numerical values ​​and ranges involved in this application are approximate values. Due to the influence of the manufacturing process, there may be a certain range of errors, which can be considered negligible by those skilled in the art.

[0084] Of course, in some other embodiments, the insulating portion 123 may not be provided between the N-type passivated contact layer 121 and the P-type passivated contact layer 122, that is, the passivated contact layer 120 only includes the N-type passivated contact layer 121 and the P-type passivated contact layer 122 spaced apart. That is, there is a gap between adjacent N-type passivated contact layers 121 and P-type passivated contact layers 122. However, when the second anti-reflection layer 170 is subsequently provided, it is necessary to place the second anti-reflection layer 170 within the gap between the N-type passivated contact layer 121 and the P-type passivated contact layer 122, which makes the process relatively complex. In the embodiment of this application, the N-type passivated contact layer 121 and the P-type passivated contact layer 122 have an insulating portion 123. When providing the second anti-reflection layer 170, it is only necessary to place the second anti-reflection layer 170 on one side of the passivated contact layer 120 and the insulating portion 123, which makes the process relatively simple.

[0085] In this embodiment, the size of the heavily doped N-type region 131 in the thickness direction of the photovoltaic cell 100 can be less than or equal to 5 μm. If the size of the heavily doped N-type region 131 in the thickness direction of the photovoltaic cell 100 is too large, Auger recombination in the heavily doped N-type region 131 is easily aggravated, which can damage the cell efficiency.

[0086] For example, the size of the N-type heavily doped region 131 in the thickness direction of the photovoltaic cell 100 can be a range of 5 μm, 4.5 μm, 4 μm, 3.5 μm, 3 μm, 2.5 μm, 2 μm or any two of these. The embodiments of this application do not limit this, nor are they limited to the above examples.

[0087] In this embodiment, the size of the heavily doped P-type region 132 in the thickness direction of the photovoltaic cell 100 is less than or equal to 3 μm. If the size of the heavily doped P-type region 132 in the thickness direction of the photovoltaic cell 100 is too large, Auger recombination in the heavily doped P-type region 132 is easily aggravated, which can damage the cell efficiency.

[0088] For example, the size of the P-type heavily doped region 132 in the thickness direction of the photovoltaic cell 100 can be a range of 3 μm, 2.5 μm, 2 μm, 1.5 μm, 1 μm, 0.5 μm or any two of these. This application embodiment does not limit this, nor is it limited to the above example.

[0089] In this embodiment, the passivation contact layer 120 can have a dimension of 100nm-300nm in the thickness direction of the photovoltaic cell 100. Exemplarily, the dimension of the passivation contact layer 120 in the thickness direction of the photovoltaic cell 100 can be a range of 100nm, 150nm, 200nm, 250nm, 300nm, or any combination thereof. This embodiment does not limit this range, nor is it limited to the above example.

[0090] See Figures 2 to 4 As shown in the embodiments of this application, the photovoltaic cell 100 may further include: a first passivation layer 140, wherein the first passivation layer 140 may be located between the substrate layer 110 and the passivation contact layer 120.

[0091] The material used for the first passivation layer 140 can be silicon dioxide or the like. This application does not limit this, nor is it limited to the above examples.

[0092] In this embodiment, the dimension of the first passivation layer 140 in the thickness direction of the photovoltaic cell 100 can be less than or equal to 2 nm. If the thickness of the first passivation layer 140 is too thick, it may lead to the inability of charge carriers to transport.

[0093] For example, the size of the first passivation layer 140 in the thickness direction of the photovoltaic cell 100 can be a range of 2nm, 1.5nm, 1nm, 0.5nm or any two of them. This application embodiment does not limit this, nor is it limited to the above example.

[0094] In this embodiment of the application, the photovoltaic cell 100 may further include a second passivation layer 150, wherein the second passivation layer 150 may be located on the side of the substrate layer 110 opposite to the passivation contact layer 120.

[0095] The material used for the second passivation layer 150 can be alumina or silicon dioxide, etc. This application embodiment does not limit this, nor is it limited to the above examples.

[0096] In this embodiment, the dimension of the second passivation layer 150 in the thickness direction of the photovoltaic cell 100 can be less than or equal to 15 nm. Exemplarily, the dimension of the second passivation layer 150 in the thickness direction of the photovoltaic cell 100 can be a range of 15 nm, 14 nm, 13 nm, 12 nm, 11 nm, 10 nm, 9 nm, 8 nm, 7 nm, 6 nm, 5 nm, or any combination thereof. This embodiment does not limit this range, nor is it limited to the above examples.

[0097] Continue to refer to Figures 2 to 4 As shown in the embodiments of this application, the photovoltaic cell 100 may further include a first anti-reflection layer 160, wherein the first anti-reflection layer 160 may be located on the side of the second passivation layer 150 facing away from the substrate layer 110, and the second passivation layer 150 is located between the first anti-reflection layer 160 and the substrate layer 110. The first anti-reflection layer 160 can reduce reflection.

[0098] The material used for the first anti-reflective layer 160 can be silicon nitride or the like. This application does not limit this, nor is it limited to the above examples.

[0099] In this embodiment, the dimension of the first antireflective layer 160 in the thickness direction of the photovoltaic cell 100 can be 50nm-150nm. Exemplarily, the dimension of the first antireflective layer 160 in the thickness direction of the photovoltaic cell 100 can be a range of 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, or any combination thereof. This embodiment does not limit this range, nor is it limited to the above example.

[0100] In this embodiment, the photovoltaic cell 100 may further include a second anti-reflection layer 170, wherein the second anti-reflection layer may be located on the side of the passivation contact layer 120 opposite to the first passivation layer 140, and the passivation contact layer 120 is located between the second anti-reflection layer 170 and the first passivation layer 140. The second anti-reflection layer 170 can reduce reflection.

[0101] The material used for the second anti-reflective layer 170 can be silicon nitride or the like. This application does not limit this to the above examples.

[0102] In this embodiment, the dimension of the second antireflective layer 170 in the thickness direction of the photovoltaic cell 100 can be 50nm-150nm. Exemplarily, the dimension of the second antireflective layer 170 in the thickness direction of the photovoltaic cell 100 can be a range of 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, or any combination thereof. This embodiment does not limit this range, nor is it limited to the above example.

[0103] It should be noted that the specific thickness of the first anti-reflective layer 160 depends on the adjustment of the surface reflectivity.

[0104] In this embodiment of the application, the photovoltaic cell 100 may further include a plurality of electrodes 180, wherein the N-type passivation contact layer 121 and the P-type passivation contact layer 122 are each independently connected to the electrode 180.

[0105] In one possible implementation, there can be multiple N-type passivation contact layers 121 and multiple P-type passivation contact layers 122. The multiple N-type passivation contact layers 121 and multiple P-type passivation contact layers 122 can be arranged alternately.

[0106] Examples of this application Figure 4 The photovoltaic cells shown are in the prior art Figure 1 The performance of the photovoltaic cells shown was tested:

[0107] Under standard testing conditions, the atmospheric mass is 1.5 and the light intensity is 1000 W / m². 2 The temperature is 25℃. The following parameters are tested: open-circuit voltage, short-circuit current, fill factor, and conversion efficiency, to evaluate the performance of the solar cell.

[0108] Table 1

[0109]

[0110] According to Table 1, it can be concluded that in the embodiments of this application... Figure 4 The photovoltaic cell shown has a higher conversion efficiency than that in existing technologies. Figure 1 The conversion efficiency of the photovoltaic cell is shown.

[0111] This application provides a method for preparing a photovoltaic cell, which may specifically include:

[0112] The substrate layer 110 is textured to form a pyramidal textured surface.

[0113] Texturing, as we can understand it, is a process for treating solar-grade silicon wafers. Generally, alkaline treatment is used to obtain a pyramidal textured surface, while acid treatment is used to obtain a wormhole-like textured surface. Both pyramidal and wormhole-like textures can improve the light-trapping effect of the silicon wafer.

[0114] On the back side of the aforementioned substrate 110, a P-type doped paste (such as a boron-containing paste) or an N-type doped paste (such as a phosphorus-containing paste) is screen-printed.

[0115] The substrate 110 after the above treatment is subjected to high-temperature treatment to prepare the corresponding P-type heavily doped region or N-type heavily doped region.

[0116] The above materials are subjected to wet etching to remove the undoped slurry.

[0117] A first passivation layer 140 is prepared on the back side of the aforementioned material. The thickness of the first passivation layer 140 can be 0.5 nm to 2 nm, and the material of the first passivation layer 140 can be silicon dioxide.

[0118] On the side of the first passivation layer 140 that faces away from the substrate layer 110, a passivation contact layer 120 is formed. The thickness of the passivation contact layer 120 can be 5 nm to 250 nm.

[0119] Specifically, on the side of the passivated contact layer 120 facing away from the substrate layer 110, a P-type doped paste (such as a boron-containing paste) is screen-printed, and after the process is completed, an N-type doped paste (such as a phosphorus-containing paste) is screen-printed.

[0120] The battery materials that have undergone the above treatment are subjected to high-temperature treatment to prepare the corresponding N-type passivation contact layer 121 and P-type passivation contact layer 122.

[0121] The battery material that has been treated as described above is then subjected to wet etching to remove the undoped slurry.

[0122] A second passivation layer 150 is formed on the side of the substrate layer 110 opposite to the first passivation layer 140. The material of the second passivation layer 150 can be alumina or silicon dioxide, and the thickness of the second passivation layer 150 can be 1 nm to 50 nm.

[0123] A first anti-reflective layer 160 is formed on the side of the second passivation layer 150 that faces away from the substrate layer 110. The thickness of the first anti-reflective layer 160 can be 50 nm to 200 nm.

[0124] A second antireflective layer 170 is formed on the side of the first passivation layer 140 that faces away from the substrate layer 110. The thickness of the second antireflective layer 170 can be 50 nm to 200 nm.

[0125] The second anti-reflective layer 170 is screen-printed on the side facing away from the first passivation layer 140 to form the electrode 180.

[0126] Specifically, in this embodiment, the N-type passivation contact layer 121 and the P-type passivation contact layer 122 can be prepared by combining screen printing paste with high-temperature treatment. This method is quick and can eliminate at least two coating processes, two laser processes, and two wet chemical etching processes in related technologies. In other words, compared with related technologies, it avoids the damage caused by two secondary laser grooving processes, further improving battery efficiency. Eliminating at least two coating processes can save costs and processing time, and eliminating two wet chemical etching processes can reduce the low yield problem caused by wet chemical etching and improve the yield rate.

[0127] Furthermore, by naturally existing intrinsic silicon insulating portion 123 between the N-type passivation contact layer 121 and the P-type passivation contact layer 122, the laser etching gap preparation step in the conventional structure is eliminated, which can further reduce laser damage.

[0128] This application embodiment also provides a photovoltaic cell module, which may include at least a housing and the aforementioned photovoltaic cell 100, wherein the photovoltaic cell 100 may be located inside the housing.

[0129] The embodiments of this application can improve the performance of photovoltaic modules by setting the photovoltaic cell 100 in the photovoltaic cell module.

[0130] In addition, this application embodiment also provides an electrical device, which may include at least the photovoltaic cell 100 or the photovoltaic cell module described above.

[0131] The electrical equipment in this application embodiment can be conventional electrical equipment in the art, such as power equipment (e.g., electric vehicles), electronic equipment (e.g., computers, mobile phones, digital cameras, printers, fax machines, etc.), wearable devices (e.g., watches, wristbands, VR glasses, etc.), and home appliances (e.g., air conditioners, refrigerators, washing machines, microwave ovens, etc.), etc., and there are no special limitations on this.

[0132] The embodiments of this application can improve the performance of electrical equipment by setting the photovoltaic cell 100 or the photovoltaic cell module in the electrical equipment.

[0133] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0134] In the description of this utility model, it should be understood that the terms "may include" and "have" as used herein, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0135] Unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can be a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A photovoltaic cell, characterized in that, include: Substrate layer; Passivation contact layer; The passivation contact layer is stacked with the substrate layer; The passivation contact layer includes: an N-type passivation contact layer and a P-type passivation contact layer spaced apart; and heavily doped regions; the heavily doped regions are located within the substrate layer; The heavily doped region includes at least one of an N-type heavily doped region and a P-type heavily doped region, wherein the projection of the N-type heavily doped region onto the passivation contact layer along the thickness direction of the photovoltaic cell at least partially overlaps with the N-type passivation contact layer, and / or, the projection of the P-type heavily doped region onto the passivation contact layer along the thickness direction of the photovoltaic cell at least partially overlaps with the P-type passivation contact layer.

2. The photovoltaic cell according to claim 1, characterized in that, The heavily doped region is in contact with the side of the substrate layer near the passivation contact layer.

3. The photovoltaic cell according to claim 1, characterized in that, The projection of the N-type heavily doped region onto the passivation contact layer along the thickness direction of the photovoltaic cell is located within the N-type passivation contact layer, and / or, the projection of the P-type heavily doped region onto the passivation contact layer along the thickness direction of the photovoltaic cell is located within the P-type passivation contact layer.

4. The photovoltaic cell according to claim 1, characterized in that, The passivated contact layer further includes an insulating portion; the insulating portion is located between the N-type passivated contact layer and the P-type passivated contact layer.

5. The photovoltaic cell according to claim 4, characterized in that, The width of the insulating part is greater than 0 and less than or equal to 100 μm.

6. The photovoltaic cell according to claim 4, characterized in that, The crystallinity of the insulating portion is greater than that of the N-type passivation contact layer; And / or, the crystallinity of the insulating portion is greater than the crystallinity of the P-type passivation contact layer.

7. The photovoltaic cell according to claim 6, characterized in that, The crystallinity of the N-type passivated contact layer is 85%-90%; and / or, The crystallinity of the P-type passivation contact layer is 85%-90%; and / or, The crystallinity of the insulating part is higher than 90%.

8. The photovoltaic cell according to any one of claims 1-7, characterized in that, The N-type heavily doped region has a dimension of less than or equal to 5 μm in the thickness direction of the photovoltaic cell.

9. The photovoltaic cell according to any one of claims 1-7, characterized in that, The P-type heavily doped region has a dimension of less than or equal to 3 μm in the thickness direction of the photovoltaic cell.

10. The photovoltaic cell according to any one of claims 1-7, characterized in that, The passivation contact layer has a dimension of 100nm-300nm in the thickness direction of the photovoltaic cell.

11. The photovoltaic cell according to any one of claims 1-7, characterized in that, Also includes: First passivation layer; The first passivation layer is located between the substrate layer and the passivation contact layer.

12. The photovoltaic cell according to claim 11, characterized in that, The first passivation layer has a dimension of less than or equal to 2 nm in the thickness direction of the photovoltaic cell.

13. The photovoltaic cell according to any one of claims 1-7, characterized in that, Also includes: The second passivation layer is located on the side of the substrate layer opposite to the passivation contact layer.

14. The photovoltaic cell according to claim 13, characterized in that, The second passivation layer has a dimension of less than or equal to 15 nm in the thickness direction of the photovoltaic cell.

15. The photovoltaic cell according to claim 13, characterized in that, Also includes: A first anti-reflective layer; the first anti-reflective layer is located on the side of the second passivation layer that faces away from the substrate layer.

16. The photovoltaic cell according to claim 15, characterized in that, The first anti-reflective layer has a dimension of 50nm-150nm in the thickness direction of the photovoltaic cell.

17. The photovoltaic cell according to claim 11, characterized in that, Also includes: The second anti-reflective layer is located on the side of the passivated contact layer that is opposite to the first passivation layer.

18. The photovoltaic cell according to claim 17, characterized in that, The second antireflective layer has a dimension of 50nm-150nm in the thickness direction of the photovoltaic cell.

19. The photovoltaic cell according to any one of claims 1-7, characterized in that, Also includes: Multiple electrodes; The N-type passivation contact layer and the P-type passivation contact layer are each independently connected to the electrode.

20. The photovoltaic cell according to claim 19, characterized in that, The number of N-type passivation contact layers is multiple, and the number of P-type passivation contact layers is multiple; Multiple N-type passivated contact layers and multiple P-type passivated contact layers are arranged alternately at intervals.

21. A photovoltaic cell module, characterized in that, It includes at least a housing and a photovoltaic cell as described in any one of claims 1-20; the photovoltaic cell is located inside the housing.

22. An electrical appliance, characterized in that, It includes at least the photovoltaic cell as described in any one of claims 1-20 or the photovoltaic cell module as described in claim 21.

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