Photovoltaic cell and photovoltaic module

Abstract

The invention provides a photovoltaic cell and a photovoltaic module, the photovoltaic cell comprises a substrate, a first tunneling layer, a first doped silicon layer, a first passivation layer and a back metal grid line, the substrate comprises a substrate front side and a substrate back side, the first tunneling layer is arranged on the substrate back side, the surface of the first tunneling layer comprises a first area and a second area, and the second area is arranged on the substrate front side. The first doped silicon layer is arranged in the first region, the conduction type of the first doped silicon layer is opposite to that of the substrate, the first passivation layer covers the second region and the surface of the first doped silicon layer, and the back metal grid line penetrates through the first passivation layer and is connected to the first doped silicon layer. According to the photovoltaic cell, the light absorption of the doped silicon layer is improved, and the photoelectric conversion efficiency is improved.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of photovoltaic cells, and in particular to a photovoltaic cell and a photovoltaic module. Background Art

[0002] A photovoltaic cell (PV) is a component that converts solar energy into electrical energy. When sunlight irradiates the semiconductor material on the surface of the photovoltaic cell, the semiconductor material absorbs the energy of photons, enabling the electrons in the semiconductor atoms to obtain sufficient energy to be excited from the covalent bond and form free electrons. These free electrons are separated under the action of the PN junction electric field to form a current, thereby driving the load to work. There are various types of photovoltaic cells, which can be classified into multiple types according to different materials, structures, and working principles. From a structural perspective, photovoltaic cells can be divided into PERC (Passivated Emitter and Rear Cell) cells, TOPCon (Tunnel Oxide Passivated Contact) cells, HJT cells, and IBC (Interdigitated Back Contact) cells, etc.

[0003] Improving the photoelectric conversion efficiency of photovoltaic cells is an eternal pursuit in the development of photovoltaic cell technology. With the increasing global energy demand and the urgent need for clean energy, scientists and engineers have been continuously exploring and innovating to achieve more efficient and economical solar energy conversion technologies. By optimizing the cell structure, improving material selection, enhancing light absorption ability, reducing carrier recombination losses, and adopting advanced manufacturing processes, photovoltaic cells are moving towards higher conversion efficiency.

[0004] Improving the photoelectric conversion efficiency of photovoltaic cells can be achieved through multiple aspects such as optimizing material selection, optimizing the cell structure, improving manufacturing processes, improving cell packaging technology, and system-level optimization. Among them, optimizing the cell structure is a relatively important method. Referring to Figure 1 As shown, taking the TOPCon cell as an example, its general structure includes an n-type substrate, with an ultra-thin tunneling layer, a p-doped silicon layer, and a back surface reflector layer sequentially on the back of the n-type substrate, and a p+ emitter layer, a passivation layer, and an antireflection layer sequentially on the front of the n-type substrate. It can be seen that the TOPCon cell is composed of a layer of ultra-thin silicon oxide (1 - 2 nm) and a layer of phosphorus-doped microcrystalline amorphous hybrid silicon thin film through the passivated contact technology, jointly forming a passivated contact structure, effectively reducing surface recombination and metal contact recombination, enhancing the open-circuit voltage and short-circuit current of the cell, and improving the cell conversion efficiency.

[0005] Regardless of the mechanism and method of structure optimization, the common goal is to improve the photoelectric conversion efficiency of photovoltaic cells to achieve more efficient energy conversion. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a photovoltaic cell and a photovoltaic module, which can improve the light absorption of the doped silicon layer and enhance the photoelectric conversion efficiency.

[0007] To solve the above technical problem, in a first aspect, the present invention provides a photovoltaic cell, comprising: a substrate, the substrate includes a front side and a back side; a first tunneling layer, the first tunneling layer is disposed on the back side of the substrate, and the surface of the first tunneling layer includes a first region and a second region; a first doped silicon layer, the first doped silicon layer is disposed in the first region; the conductivity type of the first doped silicon layer is opposite to that of the substrate; a first passivation layer, the first passivation layer covers the second region and the surface of the first doped silicon layer; a back metal grid line, the back metal grid line penetrates through the first passivation layer and is connected to the first doped silicon layer.

[0008] Optionally, an anti-reflection layer is further provided on the surface of the first passivation layer.

[0009] Optionally, a first TCO layer is provided on the first doped silicon layer; then the first passivation layer covering the second region and the surface of the first doped silicon layer includes: the first passivation layer covering the second region and the surface of the first TCO layer; the back metal grid line penetrating through the first passivation layer and being connected to the first doped silicon layer includes: the back metal grid line penetrating through the first passivation layer and being connected to the first TCO layer.

[0010] Optionally, the material of the first TCO layer includes one or more of the following materials: ITO, FTO, AZO, and ATO.

[0011] Optionally, a diffusion layer is provided on the front side of the substrate, the conductivity type of the diffusion layer is opposite to that of the substrate, and the surface of the diffusion layer includes a third region and a fourth region; a second tunneling layer and a second doped silicon layer are sequentially provided above the third region, wherein the conductivity type of the second doped silicon layer is the same as that of the substrate; a second passivation layer is further included, the second passivation layer covers the fourth region and the second doped silicon layer; a front metal grid line, the front metal grid line penetrates through the second passivation layer and is connected to the second doped silicon layer.

[0012] Optionally, an anti-reflection layer is further provided on the second passivation layer.

[0013] Optionally, a second TCO layer is provided on the second doped silicon layer; then the second passivation layer covering the fourth region and the surface of the second doped silicon layer includes: the second passivation layer covering the fourth region and the surface of the second TCO layer; the front metal gate line passing through the second passivation layer and connecting to the second doped silicon layer includes: the front metal gate line passing through the second passivation layer and connecting to the second TCO layer.

[0014] Optionally, the material of the first TCO layer includes one or more of the following materials: ITO, FTO, AZO, and ATO.

[0015] Optionally, the material of the first passivation layer and / or the second passivation layer is one or more of the following: aluminum oxide, silicon dioxide, silicon nitride, and silicon oxynitride.

[0016] Optionally, the thickness of the first doped silicon layer and / or the second doped silicon layer is 10 um to 130 um.

[0017] Optionally, the substrate is an n-type substrate, the first doped silicon layer is a p-type doped polysilicon layer, the diffusion layer is a p-type diffusion layer, and the second doped silicon layer is an n-type doped polysilicon layer.

[0018] In a second aspect, the present invention provides a photovoltaic module, including the photovoltaic cell as described in the first aspect, and a plurality of the photovoltaic cells are electrically connected to form a photovoltaic cell string.

[0019] Compared with the prior art, the present invention has the following advantages: The photovoltaic cell includes a substrate, a first tunneling layer, a first doped silicon layer, a first passivation layer, and a back metal gate line. The substrate includes a substrate front surface and a substrate back surface. The first tunneling layer is provided on the substrate back surface, and the surface of the first tunneling layer includes a first region and a second region. The first doped silicon layer is provided in the first region, and the conductivity type of the first doped silicon layer is opposite to that of the substrate. The first passivation layer covers the second region and the surface of the first doped silicon layer, and the back metal gate line passes through the first passivation layer and connects to the first doped silicon layer. It can be seen that through the optimization of the cell structure, the light absorption of the doped silicon layer is improved, and the photoelectric conversion efficiency is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are provided to further understand the present application, and they are incorporated into and constitute a part of the present application. The accompanying drawings illustrate the embodiments of the present application and, together with the description, serve to explain the principles of the present application. In the accompanying drawings:

[0021] Figure 1 is a conventional TOPCon cell structure;

[0022] Figure 2 is a schematic structural diagram of a photovoltaic cell according to an embodiment of the present invention;

[0023] Figure 3 It is another structural schematic diagram of a photovoltaic cell according to an embodiment of the present invention;

[0024] Figure 4 It is yet another structural schematic diagram of a photovoltaic cell according to an embodiment of the present invention.

[0025] In the figure:

[0026] 110 - n-type substrate, 120 - ultra-thin tunneling layer, 130 - p-doped silicon layer, 140 - back surface reflector, 150 - p+ emitter layer, 160 - passivation layer, 170 - antireflection layer, 180 - back surface metal grid line, 190 - front surface metal grid line;

[0027] 210 - substrate, 220 - first tunneling layer, 230 - first doped silicon layer, 240 - first passivation layer, 250 - second doped silicon layer, 260 - second passivation layer, 270 - first TCO layer, 280 - second tunneling layer, 290 - second TCO layer, 310 - diffusion layer. Detailed implementation manners

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, the present application can also be applied to other similar scenarios based on these drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the figures represent the same structure or operation.

[0029] For the sake of convenience in description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" and the like can be used here to describe the spatial position relationship between a device or feature shown in the figure and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the figure. For example, if the device in the figure is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding explanations are made for the spatial relative descriptions used here.

[0030] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is merely for the convenience of distinguishing the corresponding components. Without additional statements, the above terms have no special meanings, and thus should not be construed as limiting the protection scope of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some of the terms mentioned in the specification of this application may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of this description. In addition, it is required to understand this application not only through the actual terms used, but also through the meanings implied by each term.

[0031] Referring to Figure 2 As shown, a photovoltaic cell provided in this embodiment includes a substrate 210, a first tunneling layer 220, a first doped silicon layer 230, a first passivation layer 240, and a back metal grid line 180. The substrate 210 includes a substrate front surface and a substrate back surface. The first tunneling layer 220 is disposed on the substrate back surface, and the surface of the first tunneling layer 220 includes a first region and a second region. The first doped silicon layer 230 is disposed in the first region. The conductivity type of the first doped silicon layer 230 is opposite to that of the substrate. The first passivation layer 240 covers the second region and the surface of the first doped silicon layer 230, and the back metal grid line 180 passes through the first passivation layer 240 and is connected to the first doped silicon layer 230.

[0032] In this embodiment, the substrate back surface has a first tunneling layer 220 and a first doped silicon layer 230. Different from the conventional structure, the first tunneling layer 220 of this photovoltaic cell entirely covers the substrate back surface, and the first doped silicon layer 230 is only in the first region of the first tunneling layer 220, that is, the back metal contact region. Through this structure, the light absorption of the first doped silicon layer 230 is improved, and the conversion efficiency can be increased by more than 0.15% abs. In the first region (metal contact region), the first doped silicon layer 230 provides a good ohmic contact and reduces the contact resistance to improve the fill factor (FF) and conversion efficiency of the photovoltaic cell. In the second region (non-metal region), in the absence of the first doped silicon layer 230, the first tunneling layer 220 (such as SiOx) provides a full-region passivation effect, reducing the recombination of carriers on the surface of the photovoltaic cell and increasing the open-circuit voltage of the photovoltaic cell.

[0033] In an example, an anti-reflection layer 140 is further provided on the surface of the first passivation layer 240. The anti-reflection layer 140 can protect the photovoltaic cell from environmental factors such as ultraviolet rays, humidity, temperature changes, chemical corrosion, etc. Exemplarily, the following materials are used as the anti-reflection layer 140, such as polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), and fluorocarbon coatings (FEVE), etc. The appropriate material can be selected as the anti-reflection layer 140 according to different actual usage situations or cost considerations and other factors.

[0034] Reference Figure 3 As shown, a first TCO layer 270 is disposed on the first doped silicon layer 230. Specifically, the first passivation layer 240 covers the second region and the surface of the first doped silicon layer 230, that is, the first passivation layer 240 covers the second region and the surface of the first TCO layer 270. The back metal gate line 180 passes through the first passivation layer 240 and is connected to the first doped silicon layer 230. Specifically, the back metal gate line 180 passes through the first passivation layer 240 and is connected to the first TCO layer 270.

[0035] In this embodiment, the first TCO layer 270 (Transparent Conductive Oxide) can achieve a relatively high light transmittance and electrical conductivity, so that the prepared photovoltaic cell has a relatively small series resistance and a relatively high fill factor, greatly improving the photoelectric conversion efficiency of the photovoltaic cell. In short, the first TCO layer 270 can reduce the contact resistivity, provide good electrical conductivity and reduce recombination, and improve the overall performance of the photovoltaic cell.

[0036] In one example, the material of the first TCO layer 270 includes one or more of the following materials: ITO (Indium Tin Oxide), FTO (Fluorine-doped Tin Oxide), AZO (Aluminum-doped Zinc Oxide), and ATO (Antimony-doped Tin Oxide). Exemplarily, the ITO layer (Indium Tin Oxide) can reduce the contact resistivity, provide good electrical conductivity and reduce recombination, and improve the cell efficiency by more than 0.2% abs. The improvement of the cell efficiency by other materials will not be elaborated one by one.

[0037] Reference Figure 4 As shown, in one example, a diffusion layer 310 is provided on the front surface of the substrate. The conductivity type of the diffusion layer 310 is opposite to that of the substrate 210. The surface of the diffusion layer 310 includes a third region and a fourth region. A second tunneling layer 280 and a second doped silicon layer 250 are sequentially disposed above the third region, wherein the conductivity type of the second doped silicon layer 250 is the same as that of the substrate 210. A second passivation layer 260 and a front metal gate line 190 are further included. The second passivation layer 260 covers the fourth region and the second doped silicon layer 250, and the front metal gate line 190 passes through the second passivation layer 260 and is connected to the second doped silicon layer 250.

[0038] In this embodiment, the front surface of the photovoltaic cell is structurally optimized. The front surface of the substrate has a diffusion layer 310. The high-quality diffusion layer 310 has a low defect density, which helps to reduce the leakage current in the cell, thereby improving the performance and reliability of the cell. Above the third region of the diffusion layer 310, there are also a second tunneling layer 280 and a second doped silicon layer 250. The second tunneling layer 280 and the second doped silicon layer 250 work together in this structured photovoltaic cell to achieve excellent surface passivation and selective collection of carriers.

[0039] In one example, an antireflection layer 170 is also provided on the second passivation layer 260. The antireflection layer 170 can improve the light absorption rate. By reducing the light reflection on the surface of the photovoltaic cell and increasing the light transmittance, it can improve the light absorption rate and photoelectric conversion efficiency of the photovoltaic cell.

[0040] In this embodiment, the material of the antireflection layer 170 can be one or several of the following: silicon nitride (SiNx) thin film. The refractive index of the silicon nitride thin film varies with the x value between 1.8 and 2.7, and it has excellent passivation performance, improving the photoelectric conversion efficiency. Nano-porous SiOx thin film, which has a lower refractive index. When it forms a double-layer or multi-layer antireflection film with other materials with different refractive indices (such as SiNx, TiO2, etc.), a good antireflection effect can be obtained, improving the photoelectric conversion efficiency of the solar cell. ITO (indium tin oxide) thin film. The refractive index of the ITO thin film is usually about 2.1. In order to match the refractive indices of the ITO thin film and the SiOx thin film, a transition layer can be introduced as needed. The ITO thin film is also used as an antireflection layer in crystalline silicon solar cells. 2 (titanium dioxide), TiO 2 It can form a double-layer or multi-layer antireflection film with other materials to improve the photoelectric conversion efficiency of the solar cell.

[0041] In one example, if a second TCO layer 290 is provided on the second doped silicon layer 250, then the second passivation layer 260 covering the fourth region and the surface of the second doped silicon layer 250 specifically means that the second passivation layer 260 covers the fourth region and the surface of the second TCO layer 290. The front metal grid line 190 passing through the second passivation layer 260 and connecting to the second doped silicon layer 250 specifically means that the front metal grid line 190 passes through the second passivation layer 260 and connects to the second TCO layer 290.

[0042] The same principle as the first TCO layer 270, the second TCO layer 290 in this embodiment can also reduce the contact resistivity, provide good conductivity and reduce recombination, and improve the overall performance of the photovoltaic cell. Further, the material of the second TCO layer 290 includes one or more of the following materials: ITO, FTO, AZO and ATO, which will not be repeated here. Through the above-mentioned battery structure, the front structure of the battery is optimized, the second TCO layer 290 reduces the contact resistivity, provides good conductivity and reduces recombination, and improves the efficiency by more than 0.25% abs.

[0043] In one example, the material of the first passivation layer 240 and / or the second passivation layer 260 is one or more of the following: aluminum oxide, silicon dioxide, silicon nitride, and silicon oxynitride. For example, there is only one aluminum oxide layer, or a stacked structure of an aluminum oxide layer and silicon nitride. These materials work together to provide an excellent front / back passivation effect for the photovoltaic cell, reduce the surface recombination of carriers, and improve the photoelectric conversion efficiency of the photovoltaic cell.

[0044] In one example, the thickness of the first doped silicon layer 230 and / or the second doped silicon layer 250 is 10 um to 130 um.

[0045] In one example, the substrate 210 is an n-type substrate, the first doped silicon layer 230 is a p-type doped polysilicon layer, the diffusion layer 310 is a p-type diffusion layer, and the second doped silicon layer 250 is an n-type doped polysilicon layer.

[0046] N-type photovoltaic cells have higher conversion efficiency. Compared with p-type photovoltaic cells, n-type photovoltaic cells have lower effective mass of electrons and higher migration rate, which directly affects the open circuit voltage and short circuit current, so they have higher photoelectric conversion efficiency. N-type photovoltaic cells have higher bifaciality and lower temperature coefficient. Under different lighting conditions and temperature changes, n-type photovoltaic cells can maintain more stable power generation performance. In addition, n-type photovoltaic cells have almost no light decay phenomenon and better weak light effect, which enables n-type photovoltaic cells to have better power generation performance even under unsatisfactory lighting conditions. The use of n-type substrates in TOPCon cells, combined with tunneling oxide layer passivation contact technology, greatly reduces the loss caused by carrier recombination and improves the cell conversion efficiency.

[0047] In this embodiment of the photovoltaic cell, the substrate 210 includes a front side and a back side of the substrate. The first tunneling layer 220 is disposed on the back side of the substrate, and the surface of the first tunneling layer 220 includes a first region and a second region. The first doped silicon layer 230 is disposed in the first region, and the conductivity type of the first doped silicon layer 230 is opposite to that of the substrate 210. The first passivation layer 240 covers the second region and the surface of the first doped silicon layer 230. The back metal grid line 180 passes through the first passivation layer 240 and is connected to the first doped silicon layer 230, thereby improving the light absorption of the doped silicon layer and enhancing the photoelectric conversion efficiency.

[0048] Another embodiment of the present invention provides a photovoltaic module, which includes the photovoltaic cell in the foregoing embodiment. A plurality of photovoltaic cells are electrically connected to form a photovoltaic cell string, and one or more photovoltaic cell strings ultimately form a photovoltaic module (or a photovoltaic system). The electrical connection manners of these photovoltaic cells include series connection and / or parallel connection. Series connection can increase the voltage of the entire module. When multiple photovoltaic cells are connected in series, their voltages will be added together, which is beneficial for modules that require a higher voltage (such as those connected to an inverter or a charge controller). In addition, series connection simplifies the wiring because there is only one current path, thereby reducing the number and size of the wires required. Parallel connection can increase the total current output of the module while keeping the voltage unchanged. This manner provides better fault tolerance and flexibility because each photovoltaic cell works independently, and the failure of one photovoltaic cell will not affect the operation of other photovoltaic cells.

[0049] In practical applications, electrical connection is usually performed in a combination of series and parallel manners to form a photovoltaic module or a photovoltaic array to obtain the best energy output and cost-effectiveness. For example, a certain number of photovoltaic cells can be connected in series, and then these series-connected photovoltaic cells can be connected in parallel, which can increase both the voltage and the current and improve the overall performance of the module. Generally speaking, which connection manner to choose depends on the specific requirements of the module, the installation environment, and the considerations of reliability and cost-effectiveness.

[0050] It can be understood that a photovoltaic module generally also includes other conventional components. For example, an encapsulation adhesive film for covering the surface of the photovoltaic module, a cover plate for covering the surface of the encapsulation adhesive film facing away from the photovoltaic module, etc. These other conventional components of the photovoltaic module will not be elaborated here as they do not affect the understanding of the essence of this embodiment.

[0051] In the photovoltaic module of this embodiment, the substrate 210 of the photovoltaic cell includes a front side and a back side of the substrate. The first tunneling layer 220 is disposed on the back side of the substrate, and the surface of the first tunneling layer 220 includes a first region and a second region. The first doped silicon layer 230 is disposed in the first region, and the conductivity type of the first doped silicon layer 230 is opposite to that of the substrate 210. The first passivation layer 240 covers the second region and the surface of the first doped silicon layer 230. The back metal grid line 180 passes through the first passivation layer 240 and is connected to the first doped silicon layer 230, thereby improving the light absorption of the doped silicon layer and enhancing the photoelectric conversion efficiency.

[0052] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only an example and does not constitute a limitation to this application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are proposed in this application, so such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of this application.

[0053] Similarly, it should be noted that, in order to simplify the description of this application disclosure and thus assist in the understanding of one or more inventive embodiments, in the foregoing description of the embodiments of this application, sometimes multiple features are incorporated into one embodiment, drawing, or description thereof. However, this disclosure method does not mean that the features required by the subject matter of this application are more than those mentioned in the claims. In fact, the features of the embodiments are fewer than all the features of the single embodiment disclosed above.

[0054] Although this application has been described with reference to the current specific embodiments, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate this application, and various equivalent changes or substitutions can be made without departing from the spirit of this application. Therefore, as long as the changes and variations of the above embodiments are within the scope of the spirit of this application, they will fall within the scope of the claims of this application.

Claims

1. A photovoltaic cell, characterized in that: include: A substrate, the substrate comprising a substrate front side and a substrate back side; A first tunneling layer, wherein the first tunneling layer is disposed on the back side of the substrate, and a surface of the first tunneling layer includes a first region and a second region; a first doped silicon layer, wherein the first doped silicon layer is disposed in the first region; The conductivity type of the first doped silicon layer is opposite to the conductivity type of the substrate; a first passivation layer, the first passivation layer covering the second region and the surface of the first doped silicon layer; A back metal gate line passes through the first passivation layer and is connected to the first doped silicon layer.

2. The photovoltaic cell according to claim 1, characterized in that The surface of the first passivation layer also has a back reflection layer.

3. The photovoltaic cell according to claim 1, characterized in that A first TCO layer is provided on the first doped silicon layer; Then the first passivation layer covers the second region and the surface of the first doped silicon layer includes: the first passivation layer covers the second region and the surface of the first TCO layer; The back metal gate line passes through the first passivation layer and is connected to the first doped silicon layer, which includes: the back metal gate line passes through the first passivation layer and is connected to the first TCO layer.

4. The photovoltaic cell according to claim 3, characterized in that: The material of the first TCO layer includes one or more of the following materials: ITO, FTO, AZO and ATO.

5. The photovoltaic cell according to any one of claims 1 to 4, characterized in that: The front side of the substrate has a diffusion layer, the conductivity type of the diffusion layer is opposite to the conductivity type of the substrate, and the surface of the diffusion layer includes a third area and a fourth area; A second tunneling layer and a second doped silicon layer are sequentially provided on the third region, wherein the conductivity type of the second doped silicon layer is the same as that of the substrate; Also comprising a second passivation layer, wherein the second passivation layer covers the fourth region and the second doped silicon layer; A front metal gate line passes through the second passivation layer and is connected to the second doped silicon layer.

6. The photovoltaic cell according to claim 5, characterized in that: The second passivation layer is also provided with an anti-reflection layer.

7. The photovoltaic cell according to claim 5, characterized in that: A second TCO layer is provided on the second doped silicon layer; Then the second passivation layer covers the fourth region and the surface of the second doped silicon layer, including: the second passivation layer covers the fourth region and the surface of the second TCO layer; The front metal gate line passes through the second passivation layer and is connected to the second doped silicon layer, which includes: the front metal gate line passes through the second passivation layer and is connected to the second TCO layer.

8. The photovoltaic cell according to claim 7, characterized in that: The material of the second TCO layer includes one or more of the following materials: ITO, FTO, AZO and ATO.

9. The photovoltaic cell according to claim 5, characterized in that: The material of the first passivation layer and / or the second passivation layer is one or more of the following: aluminum oxide, silicon dioxide, silicon nitride and silicon oxynitride.

10. The photovoltaic cell according to claim 5, characterized in that: The thickness of the first doped silicon layer and / or the second doped silicon layer is 10 um to 130 um.

11. The photovoltaic cell according to claim 5, characterized in that: The substrate is an n-type substrate, the first doped silicon layer is a p-type doped polysilicon layer, the diffusion layer is a p-type diffusion layer, and the second doped silicon layer is an n-type doped polysilicon layer.

12. A photovoltaic module, characterized in that: The photovoltaic cell comprises the photovoltaic cell according to any one of claims 1 to 11, wherein a plurality of the photovoltaic cells are electrically connected to form a photovoltaic cell string.

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