Solar cell, photovoltaic module, and photovoltaic system

Abstract

The present disclosure is applicable to the technical field of solar power generation, and provides a solar cell, a photovoltaic module, and a photovoltaic system. The solar cell comprises a silicon substrate, a doped layer, and a passivation layer; the doped layer is arranged on the front surface and / or the back surface of the silicon substrate; the passivation layer is arranged on the side surface of the doped layer away from the silicon substrate; a plurality of grooves are formed in the back surface of a back-contact solar cell; a position where each groove is located does not comprise the passivation layer; first protruding structures connected to the doped layer are provided at a central region of the bottom of each groove. By forming the first protruding structures at the central regions of the bottoms of the grooves, when a metal gate line is subsequently printed, good ohmic contact can be formed between the metal gate line and the first protruding structures, thereby improving the charge carrier collection efficiency and improving the conversion efficiency of a cell.

Description

Solar cell, photovoltaic module and photovoltaic system

[0001] Cross-reference to related applications

[0002] The present disclosure claims priority to the Chinese patent application No. 202421960661.4, filed on August 13, 2024, entitled “Solar cell, photovoltaic module and photovoltaic system”, the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure belongs to the technical field of solar power generation, and particularly relates to a solar cell, a photovoltaic module and a photovoltaic system. BACKGROUND

[0004] A solar cell is a device that converts light energy into electrical energy through a photoelectric effect or a photochemical effect. BC (Back Contact) cells are a general term for various types of back contact structure crystalline silicon solar cells, including HPBC, TBC, HBC, etc. The back contact of a BC cell refers to the fact that the emitter electrode and the base electrode are both located on the back surface. The back contact cell structure moves the emitter electrode to the back surface of the cell, thereby reducing or eliminating the shading loss of the front grid lines and improving the cell efficiency. On the other hand, it is convenient for assembly during module packaging. Since the electrodes are all on the back surface, the spacing of the cells can be reduced, the packaging density can be improved, and the appearance is aesthetically pleasing.

[0005] BC cells require laser opening film to print metal grid lines to collect carriers. However, the current BC cells on the market cannot form a good ohmic contact when printing grid lines, which reduces the collection probability of carriers and further leads to a decrease in conversion efficiency.

[0006] SUMMARY

[0007] Embodiments of the present disclosure provide a solar cell, which aims to solve the problem of low carrier collection rate of existing solar cells, which further leads to a decrease in conversion efficiency.

[0008] Embodiments of the present disclosure are implemented in the following manner. A solar cell includes a silicon substrate, a doped layer, and a passivation layer. The front surface and / or the back surface of the silicon substrate is provided with the doped layer. The side of the doped layer away from the silicon substrate is provided with the passivation layer. The back surface of the back contact solar cell is provided with a plurality of grooves. The positions of the grooves do not include the passivation layer. The center region of the bottom of the groove is provided with a first synaptic structure connected with the doped layer.

[0009] Further, the bottom of the groove is provided with an edge region located outside the center region. The edge region is provided with a second synaptic structure.

[0010] Further, the edge region is higher than the center region in a direction pointing from the silicon substrate to the doped layer.

[0011] Further, the center region is provided with a plurality of first patches, at least part of the first synaptic structures at the junction of adjacent first patches are higher than the first synaptic structures within the first patches.

[0012] Further, the center region comprises boundaries of the tower base of the micro-pyramid structures, at least part of the first synaptic structures at the boundaries are higher than the rest of the first synaptic structures.

[0013] Further, the recess edge region extends away from the center region to form a gap space between the doped layer and the passivation layer.

[0014] Further, the passivation layer is provided with third synaptic structures on the side surface facing the gap space.

[0015] Further, the gap space is provided with fourth synaptic structures, two ends of the fourth synaptic structures are connected to the doped layer and the passivation layer respectively.

[0016] Further, the first synaptic structures, the second synaptic structures and the third synaptic structures comprise at least one of a round package, a convex tip, a spherical shape, a conical shape and an irregular shape.

[0017] Further, the maximum distance between any two points on the bottom profile of the first synaptic structures, the second synaptic structures and the third synaptic structures is less than 500 nm.

[0018] Further, the height of the first synaptic structures, the second synaptic structures and the third synaptic structures is less than 500 nm.

[0019] Further, the diameter of the recess is 12 microns to 30 microns.

[0020] In a second aspect, the present disclosure also provides a photovoltaic module comprising the solar cell as described above.

[0021] In a third aspect, the present disclosure also provides a photovoltaic system comprising the photovoltaic module as described above.

[0022] The back contact solar cell of the present disclosure includes a silicon substrate, a doped layer and a passivation layer, the back surface of the silicon substrate is provided with the doped layer, the side of the doped layer away from the silicon substrate is provided with the passivation layer, the back surface of the back contact solar cell is provided with a plurality of grooves, the positions of the grooves do not include the passivation layer, and the central region of the bottom of the groove is provided with a first synaptic structure connected with the doped layer. By forming the first synaptic structure in the central region of the bottom of the groove, when the metal grid line is printed subsequently, the metal grid line and the first synaptic structure can form good ohmic contact, thereby improving the carrier collection efficiency and the conversion efficiency of the cell. BRIEF DESCRIPTION OF DRAWINGS

[0023] Fig. 1 is a schematic diagram of a film layer structure of a laser film opening of a solar cell according to an embodiment of the present disclosure;

[0024] Fig. 2 is a schematic diagram of a laser film opening structure of a solar cell according to an embodiment of the present disclosure;

[0025] Fig. 3 is a schematic diagram of a groove structure of a solar cell according to an embodiment of the present disclosure;

[0026] Fig. 4 is a schematic diagram of a first synaptic structure of a solar cell according to an embodiment of the present disclosure;

[0027] Fig. 5 is a schematic diagram of a cross section of a groove of a solar cell according to an embodiment of the present disclosure;

[0028] Fig. 6 is a schematic diagram of a gap space of a solar cell according to an embodiment of the present disclosure;

[0029] Fig. 7 is a schematic diagram of an internal interface of a groove of a solar cell according to an embodiment of the present disclosure;

[0030] Fig. 8 is a schematic diagram of a groove with a further recessed bottom of a solar cell according to an embodiment of the present disclosure;

[0031] Fig. 9 is a schematic diagram of a groove with a first piece area of a solar cell according to an embodiment of the present disclosure;

[0032] Fig. 10 is a schematic diagram of a tower base boundary of a pyramid in a groove of a solar cell according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to the drawings and embodiments. Examples of the embodiments are shown in the drawings, in which the same or similar notations denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only, and are merely used to explain the present disclosure, and should not be understood as limiting the present disclosure. In addition, it should be understood that the specific embodiments described herein are merely used to explain the present disclosure, and should not be used to limit the present disclosure.

[0034] In the description of the present disclosure, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are merely used to facilitate the description of the present disclosure and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present disclosure.

[0035] In addition, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present disclosure, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0036] In the description of the present disclosure, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.

[0037] In the present disclosure, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include the direct contact of the first and second features, or can include the contact of the first and second features through another feature between them. Moreover, the "upper", "above" and "above" of the first feature to the second feature include the vertical direction of the first feature above and obliquely above the second feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature include the vertical direction of the first feature below and obliquely below the second feature, or only indicate that the horizontal height of the first feature is less than that of the second feature.

[0038] The disclosure below provides many different embodiments or examples for implementing different structures of the disclosure. For the sake of simplicity, the description below of a particular embodiment or example refers only to the specific structure after the preparation of the drawing. Of course, this is merely an example and is intended to be illustrative only. Based on the description below, a person of ordinary skill in the art will appreciate the sufficiency and reproducibility of the different embodiments and / or settings discussed. Moreover, the disclosure provides various examples of specific processes and materials, but one of ordinary skill in the art can appreciate the application of other processes and / or the use of other materials.

[0039] The back contact solar cell of the disclosure includes a silicon substrate, a doped layer, and a passivation layer, the back surface of the silicon substrate is provided with the doped layer, the side of the doped layer away from the silicon substrate is provided with the passivation layer, the back surface of the back contact solar cell is provided with a plurality of grooves, the position of the groove does not include the passivation layer, and the central area of the bottom of the groove is provided with a first synaptic structure connected with the doped layer. By forming the first synaptic structure in the central area of the bottom of the groove, when printing the metal grid line subsequently, the metal grid line and the first synaptic structure can form a good ohmic contact, thereby improving the carrier collection efficiency and increasing the conversion efficiency of the cell.

[0040] Embodiment one

[0041] As shown in FIGS. 1-10, one embodiment of the disclosure provides a back contact solar cell, including a silicon substrate 100, a doped layer 200, and a passivation layer 300, the back surface of the silicon substrate 100 is provided with the doped layer 200, the side of the doped layer 200 away from the silicon substrate 100 is provided with the passivation layer 300, the back surface of the back contact solar cell is provided with a plurality of grooves 400, the position of the groove 400 does not include the passivation layer, i.e. the groove 400 penetrates the passivation layer 300, and the central area 410 of the bottom of the groove 400 is provided with a first synaptic structure 510 connected with the doped layer 200.

[0042] The silicon substrate 100 refers to the basic material used for semiconductor device manufacturing, which is usually a single crystal or polycrystalline material made by highly purified and crystal growth technology, which is not described in detail.

[0043] Optionally, the silicon substrate 100 can be an N-type silicon wafer or a P-type silicon wafer, wherein the N-type silicon wafer is obtained by adding a 5-valence element (such as phosphorus) to a single crystal or polycrystalline material, and the P-type silicon wafer is obtained by adding a 3-valence element (such as boron, gallium, or indium) to a single crystal or polycrystalline material, which is not described in detail.

[0044] The silicon substrate 100 has a front surface and a back surface, wherein the front surface of the silicon substrate 100 corresponds to the light-receiving surface of the solar cell, and the back surface of the silicon substrate 100 corresponds to the back surface of the solar cell.

[0045] The doped layer 200 and the passivation layer 300 are sequentially arranged on the back surface of the silicon substrate 100. In some embodiments, the doped layer 200 is further doped with a trivalent element or a pentavalent element on the basis of the silicon substrate 100. For example, when the silicon substrate 100 is an N-type silicon wafer, the emitter doped layer 200 is obtained by doping a trivalent element on the basis of the N-type silicon wafer, and the emitter doped layer 200 can be regarded as a p+ layer. Similarly, the diffusion doped layer 200 is obtained by doping a pentavalent element on the basis of the N-type silicon wafer, and the diffusion doped layer 200 can be regarded as an n+ layer.

[0046] In implementation, the passivation layer 300 is arranged on the doped layer 200. The passivation layer 300 refers to a thin film that makes the surface of the cell wafer “passivated” or become inactive. The passivation layer 300 is usually composed of at least one of silicon nitride, aluminum oxide, silicon oxynitride, and silicon oxide, which reduces the activity of the surface of the cell wafer, thereby reducing the surface recombination rate.

[0047] Optionally, the passivation layer 300 can be prepared by PECVD (plasma enhanced chemical vapor deposition) or by LPCVD (low pressure chemical vapor deposition), which will not be described herein.

[0048] After the doped layer 200 and the passivation layer 300 are prepared, a laser is used to open a film on the passivation layer 300, for example, a picosecond / femtosecond laser is used to open a film. The laser is irradiated on the target position of the passivation layer 300, so that the passivation layer 300 at the target position undergoes the process of instantaneous gasification and re-solidification under the action of the high-temperature laser spot. That is, a groove 400 is formed on the passivation layer 300 by laser opening a film, as shown in FIG. 2. The back surface of the back contact solar cell is provided with a plurality of grooves 400, and the positions where the grooves 400 are located do not include the passivation layer 300.

[0049] Optionally, the diameter of the groove 400 is 12 microns to 30 microns, for example, 13 nanometers, 14 nanometers, 15 nanometers, 18 nanometers, 20 nanometers, 25 nanometers, 27 nanometers, 29 nanometers, or any value within the range of 12 microns to 30 microns, which will not be limited.

[0050] The central region 410 of the bottom of the groove 400 is provided with a first synaptic structure 510, as shown in FIG. 1. The first synaptic structure 510 is a protrusion, for example, a columnar or conical protrusion, which is connected with the doped layer 200. The first synaptic structure 510 is formed by the doped layer 200 under the action of the high-temperature laser spot when the laser is used to open a film, which will not be described herein.

[0051] The first synaptic structure 510 is a convex structure, and when a metal grid line is printed subsequently, the metal grid line contacts and adheres to the first synaptic structure 510, thereby forming a good ohmic contact.

[0052] Optionally, the length of the bottom of the first synaptic structure 510 is less than 500 nm, for example, when the synaptic structure adopts a round package or a conical shape, the diameter of the bottom of the synaptic structure can be 5 nm, 6 nm, 7 nm, 10 nm, 15 nm, 20 nm, 50 nm, 100 nm, 200 nm, 400 nm, or any value less than 500 nm, without limitation.

[0053] In some embodiments, the height of the first synaptic structure 510 is less than 500 nm, for example, 5 nm, 6 nm, 7 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 50 nm, 100 nm, 200 nm, 400 nm, or any value less than 500 nm, without limitation.

[0054] The back contact solar cell of the present disclosure includes a silicon substrate 100, a doped layer 200, and a passivation layer 300, the back surface of the silicon substrate 100 is provided with the doped layer 200, the side of the doped layer 200 away from the silicon substrate 100 is provided with the passivation layer 300, the back surface of the back contact solar cell is provided with a plurality of grooves 400, the position of the groove 400 does not include the passivation layer 300, and the center area 410 of the bottom of the groove 400 is provided with a first synaptic structure 510 connected with the doped layer 200. By forming the first synaptic structure 510 at the center area 410 of the bottom of the groove 400, when a metal grid line is printed subsequently, the metal grid line and the first synaptic structure 510 can form a good ohmic contact, thereby improving the carrier collection efficiency and increasing the conversion efficiency of the cell.

[0055] As a way, in order to observe the synaptic structure, for example, in order to facilitate the observation of the first synaptic structure 510, the electrodes on the finished cell piece can be washed off.

[0056] In some optional embodiments, as shown in FIGS. 3 and 7, the bottom of the groove 400 is provided with an edge area 420 located outside the center area 410, and the edge area 420 is provided with a second synaptic structure 520.

[0057] The bottom of the groove 400 can be divided into a central region 410 in the middle and an edge region 420 outside the central region 410. Exemplarily, the central region 410 can be regarded as an inner circle of the bottom of the groove 400, and the edge region 420 can be regarded as an outer ring of the bottom of the groove 400. The edge region 420 is provided with the second contact structures 520, which can increase the roughness of the bottom of the groove 400, so as to better combine with the metal grid line, and make the contact between the metal grid line and the second contact structures 520 more stable, and the grid line electrode not easy to fall off.

[0058] As a possible way, the edge region 420 is higher than the central region 410 in the direction away from the silicon substrate 100, that is, the bottom of the groove 400 can be further concave, as shown in FIG. 8, to further improve the contact effect with the electrode.

[0059] Optionally, the central region 410 is provided with a plurality of first areas 411, and the height of at least part of the first contact structures 510 at the junction between adjacent first areas 411 is higher than the height of the first contact structures 510 in the first areas 411.

[0060] The central region 410 can be divided into a plurality of first areas 411, and the height of at least part of the first contact structures 510 at the junction between adjacent first areas 411 is higher, as shown in FIG. 9, 41a is the first contact structure 510 at the junction between adjacent first areas 411, and 41b is the first contact structure 510 in the first area 411. The height of part or all of the first contact structures 510 of 41a is higher than the height of the first contact structures 510 of 41b. When the electrode is printed subsequently, the electrode is connected to the doped layer 200 more stably, and the conductive performance is better.

[0061] In some possible embodiments, the first contact structures 510 at the edge of the central region 410 gradually rise to the first contact structures 510 at the center point of the central region 410, or the first contact structures 510 at the edge of the central region 410 rise to the first contact structures 510 at the center point of the central region 410 in stages, without limitation.

[0062] Further, the central region 410 includes the boundary 412 of the base of the micro-pyramid structure, as shown in FIG. 10, and the height of at least part of the first contact structures 510 at the boundary 412 is higher than the height of the remaining first contact structures 510.

[0063] The micro-pyramid structure refers to the dense micro-protrusions formed on the doped region. In general, the micro-protrusions are in the shape of a pyramid. As a possible implementation, the tips of the pyramid-shaped micro-protrusions can be removed, and the bases of the pyramid-shaped micro-protrusions can be retained. When the laser is used to open the film, part or all of the first synaptic structures 510 formed at the boundaries of the bases are higher than the rest of the first synaptic structures 510 in the groove 400, thereby improving the contact effect with the electrode.

[0064] In some optional embodiments, as shown in FIG. 6, when the laser is used to open the film, the laser spot causes delamination between the doped layer 200 and the passivation layer 300 around the groove 400, i.e., the edge region 420 extends away from the central region 410 to form a gap space 430 between the doped layer 200 and the passivation layer 300. When the metal grid is printed subsequently, the metal paste can penetrate into the gap space 430, so that the metal grid formed after solidification is more stable in connection with the battery.

[0065] In some embodiments, the side surface of the passivation layer 300 towards the gap space 430 is provided with a third synaptic structure 530. In the gap space 430, the passivation layer 300 is provided with the third synaptic structure 530. When the metal grid is printed subsequently, the metal paste penetrates into the gap space 430 and is in contact and adhesion with the third synaptic structure 530, thereby further improving the stability of the connection between the metal grid and the battery.

[0066] In some optional embodiments, the gap space 430 is provided with a fourth synaptic structure 540, and the two ends of the fourth synaptic structure 540 are connected with the doped layer 200 and the passivation layer 300, respectively. The fourth synaptic structure 540 can be regarded as a connecting column connecting the doped layer 200 and the passivation layer 300, so that the connection between the metal grid and the battery is more stable.

[0067] Optionally, the first synaptic structure 510, the second synaptic structure 520, and the third synaptic structure 530 include at least one of a round package, a convex tip, a spherical shape, a conical shape, and an irregular shape. Each synaptic structure can be a round package structure, as shown in A2 in FIG. 4. Each synaptic structure can also be a spherical structure, as shown in A1 in FIG. 4. Or a conical structure, as shown in A3 in FIG. 4. In some possible embodiments, each synaptic structure can also be a combination of various shape structures, for example, each synaptic structure can include a round package and a spherical structure at the top of the round package, or each synaptic structure can include a conical shape and a spherical structure at the top of the conical shape.

[0068] Optionally, the shape structure, size, and height of the second synaptic structure 520 and the third synaptic structure 530 can refer to the first synaptic structure 510 described above, and will not be described herein.

[0069] Embodiment Two

[0070] In some alternative embodiments, the present disclosure also provides a photovoltaic module comprising the solar cell as described above.

[0071] It is clear to those skilled in the art that, for the convenience and brevity of description, the structure and implementation principle of the photovoltaic module described above can refer to the corresponding structure and implementation principle in the aforementioned embodiment one, which will not be described here again.

[0072] The back contact solar cell of the present disclosure comprises a silicon substrate 100, a doped layer 200, and a passivation layer 300, the back surface of the silicon substrate 100 is provided with the doped layer 200, the side of the doped layer 200 away from the silicon substrate 100 is provided with the passivation layer 300, the back surface of the back contact solar cell is provided with a plurality of grooves 400, the position where the groove 400 is located does not include the passivation layer 300, and the central area 410 of the bottom of the groove 400 is provided with a first synaptic structure 510 connected with the doped layer 200. By forming the first synaptic structure 510 at the central area 410 of the bottom of the groove 400, when the metal grid line is printed subsequently, the metal grid line and the first synaptic structure 510 can form a good ohmic contact, thereby improving the carrier collection efficiency and increasing the conversion efficiency of the cell.

[0073] Embodiment three

[0074] In some alternative embodiments, the present disclosure also provides a photovoltaic system comprising the photovoltaic module as described above.

[0075] In implementation, the photovoltaic system can be applied in a photovoltaic power station, such as a ground power station, a roof power station, a water surface power station, etc., and can also be applied in a device or apparatus utilizing solar energy for power generation, such as a user solar power source, a solar street lamp, a solar car, a solar building, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be applied in all fields requiring solar energy for power generation. Taking a photovoltaic power generation system network as an example, the photovoltaic system can comprise a photovoltaic array, a combiner box, and an inverter, the photovoltaic array can be an array combination of a plurality of photovoltaic modules, for example, a plurality of photovoltaic modules can constitute a plurality of photovoltaic arrays, the photovoltaic array is connected with the combiner box, the combiner box can combine the current generated by the photovoltaic array, the combined current flows through the inverter to be converted into an alternating current required by a power grid, and then is connected to a power network to realize solar power supply.

[0076] It is clear to those skilled in the art that, for the convenience and brevity of description, the structure and implementation principle of the photovoltaic system described above can refer to the corresponding structure and implementation principle in the aforementioned embodiments one and two, which will not be described here again.

[0077] The back contact solar cell of the present disclosure comprises a silicon substrate 100, a doped layer 200 and a passivation layer 300, the back surface of the silicon substrate 100 is provided with the doped layer 200, the side of the doped layer 200 away from the silicon substrate 100 is provided with the passivation layer 300, the back surface of the back contact solar cell is provided with a plurality of grooves 400, the position where the groove 400 is located does not include the passivation layer 300, and the central area 410 of the bottom of the groove 400 is provided with a first synaptic structure 510 connected with the doped layer 200. By forming the first synaptic structure 510 at the central area 410 of the bottom of the groove 400, when the metal grid line is printed subsequently, the metal grid line and the first synaptic structure 510 can form a good ohmic contact, thereby improving the carrier collection efficiency and the conversion efficiency of the cell.

[0078] The above only describes the preferred embodiments of the present disclosure and is not intended to limit the present disclosure. Any modification, equivalent replacement and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A back contact solar cell, characterized by, The back surface of the back contact solar cell is provided with a plurality of grooves, the grooves are located at positions not including the passivation layer, the center area of the bottom of the groove is provided with a first synaptic structure connected with the doped layer.

2. The solar cell of claim 1, wherein, The bottom of the groove is provided with an edge area located outside the center area, and the edge area is provided with a second synaptic structure.

3. The solar cell of claim 2, wherein the first and second doped regions are formed by implanting dopants into the first and second surfaces of the substrate. In the direction from the silicon substrate to the doped layer, the edge area is higher than the center area.

4. The solar cell according to any one of claims 1 to 3, wherein The center area is provided with a plurality of first patches, and the height of at least part of the first synaptic structure at the junction between adjacent first patches is higher than the height of the first synaptic structure within the first patch.

5. The solar cell of claim 1, wherein the first and second electrodes are formed of a material selected from the group consisting of silver, aluminum, gold, copper, and combinations thereof. The center area includes the boundary of the tower base of the micro-pyramid structure, and the height of at least part of the first synaptic structure located at the boundary is higher than the height of the remaining first synaptic structure.

6. The solar cell of claim 2, wherein the first and second doped regions are formed by implanting dopants into the first and second surfaces of the substrate. The edge area of the groove extends away from the center area to form a gap space between the doped layer and the passivation layer.

7. The solar cell of claim 6, wherein the first and second doped regions are formed by implanting dopants into the first and second surfaces of the substrate. The side surface of the passivation layer towards the gap space is provided with a third synaptic structure.

8. The solar cell according to claim 6 or 7, wherein the semiconductor layer is a p-type semiconductor layer. The gap space is provided with a fourth synaptic structure, and the two ends of the fourth synaptic structure are respectively connected with the doped layer and the passivation layer.

9. The solar cell of claim 7, wherein the first and second doped regions are formed by implanting dopants into the first and second surfaces of the substrate. The first synaptic structure, the second synaptic structure and the third synaptic structure include at least one of a round package, a convex tip, a spherical shape, a conical shape and an irregular shape.

10. The solar cell of claim 7, wherein the first and second electrodes are formed of a material selected from the group consisting of silver, aluminum, gold, copper, and combinations thereof. The maximum distance between any two points on the bottom contour of the first synaptic structure, the second synaptic structure and the third synaptic structure is less than 500nm.

11. The solar cell of claim 7, wherein the first and second electrodes are formed of a material selected from the group consisting of silver, aluminum, gold, copper, and combinations thereof. The height of the first synaptic structure, the second synaptic structure and the third synaptic structure is less than 500nm.

12. The solar cell of claim 1, wherein, The diameter of the groove is 12 microns to 30 microns.

13. A photovoltaic module, characterized by The solar cell as claimed in any one of claims 1 to 12.

14. A photovoltaic system characterized by, The photovoltaic module as claimed in claim 13.

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