Solar cell and photovoltaic module

Abstract

The utility model provides a solar cell and a photovoltaic module, the solar cell comprises a substrate and two groups of electrodes, and the two groups of electrodes are respectively formed on two opposite sides of the substrate. The electrode comprises a plurality of grid line structures which are arranged at intervals. The base body comprises a substrate layer and two groups of doping layers which are respectively arranged on two opposite sides of the substrate layer; a plurality of concave parts are formed in the surface of one side, far away from the substrate layer, of the doping layer, and the concave parts and the grid line structures are staggered in position, so that convex structures are formed in the positions, corresponding to the grid line structures, of the doping layer. Therefore, light parasitic absorption can be reduced, and optical loss is reduced.

Description

Technical Field

[0001] The present disclosure relates to the field of solar energy technologies, and particularly to a solar cell and a photovoltaic module. Background Art

[0002] A solar cell can collect photo-generated carriers generated by the photovoltaic effect through a PN junction. The aggregation of photo-generated carriers can generate a stable electric potential, thereby enabling power generation using sunlight. The doping layer of some solar cells uses amorphous silicon or nanocrystalline silicon. Among them, the band gap width of the amorphous silicon film ranges from 1.6 eV to 2.0 eV, and the band gap width of the nanocrystalline silicon is about 2.5 eV. The energy range of the light mainly utilized by the solar cell is from 1.62 eV to 3.11 eV. Therefore, a large part of it will be absorbed and recombined by the amorphous silicon or nanocrystalline silicon, resulting in serious optical parasitic absorption and large optical losses. Summary of the Utility Model

[0003] The present disclosure provides a solar cell and a photovoltaic module, which can reduce optical parasitic absorption and thus reduce optical losses.

[0004] The present disclosure provides a solar cell, including a substrate and two sets of electrodes. The two sets of electrodes are respectively formed on opposite sides of the substrate; the electrodes include multiple grid line structures arranged at intervals; the substrate includes a substrate layer and two sets of doping layers respectively disposed on opposite sides of the substrate layer;

[0005] On the surface of the doping layer away from the substrate layer, a plurality of recessed portions are formed, and the positions of the recessed portions are offset from the positions of the grid line structures, so that a convex structure is formed at the position of the doping layer corresponding to the grid line structures.

[0006] Further, the convex structure extends along the length direction of the grid line structure, and a plurality of the convex structures are arranged at intervals in the width direction of the grid line structure.

[0007] Further, the two sets of doping layers include an N-type doping layer and a P-type doping layer, and the N-type doping layer and the P-type doping layer are respectively disposed on opposite sides of the substrate layer.

[0008] Further, a plurality of first recessed portions are formed on the surface of the N-type doping layer away from the substrate layer, so that a first convex structure is formed at the position of the N-type doping layer corresponding to the grid line structures; the thickness range of the first convex structure is between 25 nm and 35 nm; and / or

[0009] On the surface of the P-type doped layer away from the substrate layer, a plurality of second recessed portions are formed, so that a second protruding structure is formed at the position of the P-type doped layer corresponding to the gate line structure; the thickness of the second protruding structure ranges from 35 nm to 45 nm.

[0010] Further, the distance between the bottom surface of the first recessed portion close to the substrate layer and the side of the N-type doped layer close to the substrate layer ranges from 10 nm to 20 nm; and / or

[0011] The distance between the bottom surface of the second recessed portion close to the substrate layer and the side of the P-type doped layer close to the substrate layer ranges from 20 nm to 30 nm.

[0012] Further, the N-type doped layer is disposed on the front surface of the substrate layer, and the P-type doped layer is disposed on the back surface of the substrate layer; the thickness of the N-type doped layer is less than the thickness of the P-type doped layer.

[0013] Further, the width of the protruding structure ranges from 100 um to 150 um.

[0014] Further, the central axis of the protruding structure coincides with the central axis of the corresponding gate line structure.

[0015] Further, the substrate further includes two groups of amorphous silicon layers, the two groups of amorphous silicon layers are respectively disposed on opposite sides of the substrate layer, and the amorphous silicon layer is located between the substrate layer and the doped layer; and / or

[0016] The substrate further includes two groups of conductive thin films, the two groups of conductive thin films are respectively disposed on opposite sides of the substrate layer, and the conductive thin film is located on the side of the doped layer away from the substrate layer; wherein, the electrode is formed on the outer surface of the conductive thin film.

[0017] Further, the solar cell is a heterojunction cell.

[0018] The present disclosure provides a photovoltaic module, wherein the photovoltaic module includes a plurality of solar cells as described in any one of the above embodiments.

[0019] The substrate of the solar cell provided by the present disclosure includes a substrate layer and two groups of doped layers respectively disposed on opposite sides of the substrate layer. A plurality of recessed portions are formed on the surface of the doped layer away from the substrate layer, and the positions of the recessed portions are staggered from the positions of the grid line structure, so that a raised structure is formed at the position of the doped layer corresponding to the grid line structure. Thus, the thickness of the doped layer at the position corresponding to the grid line structure is greater than the thickness of the doped layer at the position of the non-grid line structure. By selectively using doped layers with different thicknesses, the electric field strength at the position of the grid line structure can be enhanced. Therefore, while ensuring the collection of photo-generated carriers and the open-circuit voltage, the thickness of the doped layer at the position of the non-grid line structure can be reduced to reduce optical parasitic absorption, lower optical loss, increase the short-circuit current of the solar cell, and improve the light conversion efficiency of the solar cell.

[0020] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present disclosure and, together with the specification, are used to explain the principles of the present disclosure.

[0022] Figure 1 The figure shows a schematic structural diagram of a solar cell according to an exemplary embodiment of the present disclosure;

[0023] Figure 2 The figure shows a flowchart of a method for manufacturing a solar cell according to an exemplary embodiment of the present disclosure.

[0024] The reference numerals are as follows: solar cell 10, substrate 11, electrode 12, positive electrode 13, negative electrode 14, substrate layer 15, doped layer 16, N-type doped layer 17, P-type doped layer 18, grid line structure 19, raised structure 20, first raised structure 21, second raised structure 22, amorphous silicon layer 23, first amorphous silicon layer 24, second amorphous silicon layer 25, conductive thin film 26, first conductive thin film 27, second conductive thin film 28, recessed portion 29, first recessed portion 30, second recessed portion 31. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] Here, the exemplary embodiments will be described in detail, and the examples are shown in the accompanying drawings. When the following description refers to the accompanying drawings, unless otherwise indicated, the same numerals in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0026] To better understand the technical solutions of the present disclosure, the solar cell and photovoltaic module of the present disclosure will be introduced in detail below with reference to the accompanying drawings. Without conflict, the features in the following embodiments and implementation manners can be combined with each other.

[0027] Referring to Figure 1 As shown, an embodiment of the present disclosure provides a solar cell 10, and the solar cell 10 may be a heterojunction cell. The heterojunction cell has characteristics such as high efficiency and high open-circuit voltage. The solar cell 10 includes a substrate 11 and two sets of electrodes 12, and the two sets of electrodes 12 are respectively formed on opposite sides of the substrate 11. The two sets of electrodes 12 may include a positive electrode 13 and a negative electrode 14. Among them, the negative electrode 14 may be formed on the light-receiving surface side of the substrate 11, and the positive electrode 13 may be formed on the backlight surface side of the substrate 11. The light-receiving surface refers to the side facing the light source and receiving light, and the backlight surface refers to the side facing away from the light source.

[0028] The electrode 12 includes a plurality of grid line structures 19 arranged at intervals. The plurality of grid line structures 19 may be arranged evenly. The substrate 11 includes a substrate layer 15 and two sets of doped layers 16 respectively disposed on opposite sides of the substrate layer 15. The substrate layer 15 may be monocrystalline silicon, such as N-type monocrystalline silicon or P-type monocrystalline silicon. A plurality of recesses 29 are formed on the surface of the doped layer 16 away from the substrate layer 15, and the positions of the recesses 29 are staggered from the positions of the grid line structures 19, so that a convex structure 20 is formed at the position of the doped layer 16 corresponding to the grid line structures 19. The shape of the convex structure 20 may be the same as the shape of the grid line structures 19. Each grid line structure 19 may be correspondingly provided with a convex structure 20. Between two adjacent convex structures 20, there may also be at least one grid line structure 19 that is not correspondingly provided with a convex structure 20. Optionally, the number of the convex structures 20 may be multiple, and the multiple convex structures 20 may be arranged at intervals in the width direction X of the grid line structures 19, and the convex structures 20 may extend along the length direction Y of the grid line structures 19. A plurality of recesses 29 are formed on the surface of the doped layer 16 away from the substrate layer 15, and a convex structure 20 is formed at the position of the doped layer 16 corresponding to the grid line structures 19. Thus, the thickness of the doped layer 16 at the position corresponding to the grid line structures 19 is greater than the thickness of the doped layer 16 at the position of the non-grid line structure, that is, the position of the doped layer corresponding to the grid line structures 19 bulges and has a greater thickness, and the thickness of the position not corresponding to the grid line structures 19 is relatively thinner. In this way, a thickness difference of the doped layer can be formed. By selectively doping layers 16 with different thicknesses, the electric field strength at the position of the grid line structures 19 can be enhanced. Thus, while ensuring the collection of photo-generated carriers and the open-circuit voltage, the thickness of the doped layer 16 at the position of the non-grid line structure can be thinned to reduce optical parasitic absorption, reduce optical loss, increase the short-circuit current of the solar cell, and improve the light conversion efficiency of the solar cell.

[0029] In one embodiment, the central axis of the convex structure 20 coincides with the central axis of the corresponding gate line structure 19. In this way, the gate line structure 19 can block at least part of the convex structure 20, which is beneficial to reducing optical parasitic absorption and lowering optical loss.

[0030] In one embodiment, the convex structure 20 extends along the length direction of the gate line structure 19, and a plurality of the convex structures 20 are arranged at intervals in the width direction of the gate line structure 19. In this way, the position of the doping layer corresponding to the gate line structure protrudes and has a greater thickness, while the position not corresponding to the gate line structure has a relatively thinner thickness, so that a thickness difference of the doping layer can be formed.

[0031] In one embodiment, the width of the convex structure 20 ranges from 100 μm to 150 μm. The width of the convex structure 20 can refer to the size of the convex structure 20 in the width direction X of the gate line structure 19. The width of the convex structure 20 can be 100 μm, 120 μm, 130 μm, 150 μm, etc. In this way, the width of the convex structure 20 is appropriate, which can effectively enhance the electric field strength at the gate line structure 19 while ensuring the reduction of optical parasitic absorption.

[0032] In one embodiment, the two groups of doping layers 16 include an N-type doping layer 17 and a P-type doping layer 18, and the N-type doping layer 17 and the P-type doping layer 18 are respectively arranged on opposite sides of the substrate layer 15. The N-type doping layer 17 can be N-type microcrystalline silicon, N-type amorphous silicon, etc. The P-type doping layer 18 can be P-type microcrystalline silicon, P-type amorphous silicon, etc., and the present disclosure does not make any limitations. The above-mentioned microcrystalline silicon is also called nanocrystalline silicon, and microcrystalline silicon can be formed by doping carbon elements into crystalline silicon, so as to increase the bandgap width of microcrystalline silicon and reduce optical parasitic absorption. In one embodiment, the outer surface of the substrate 11 on the side where the N-type doping layer 17 is arranged can be the light-receiving surface, and the outer surface of the side where the P-type doping layer 18 is arranged can be the backlight surface. In another embodiment, the outer surface of the substrate 11 on the side where the N-type doping layer 17 is arranged can be the backlight surface, and the outer surface of the side where the P-type doping layer 18 is arranged can be the light-receiving surface.

[0033] In one embodiment, the N-type doping layer 17 is arranged on the front side of the substrate layer 15, and the P-type doping layer 18 is arranged on the back side of the substrate layer 15. The front side of the substrate layer 15 can be the side of the light-receiving surface, and the back side of the substrate layer 15 can be the side of the backlight surface. The thickness of the N-type doping layer 17 is less than the thickness of the P-type doping layer 18, which is easy to process, and this setting makes the thickness of the light-receiving surface side thinner and the light absorption efficiency higher.

[0034] In one embodiment, a plurality of first recesses 30 are formed on the surface of the N-type doped layer 17 on the side away from the substrate layer 15, so that a first protrusion structure 21 is formed at the position of the N-type doped layer 17 corresponding to the gate line structure 19. The thickness a of the first protrusion structure 21 ranges from 25 nm to 35 nm. The thickness of the first protrusion structure 21 may be the distance from the side of the first protrusion structure 21 away from the substrate layer 15 to the side of the N-type doped layer 17 close to the substrate layer 15. The thickness a of the first protrusion structure 21 may be 25 nm, 30 nm, 35 nm, etc. Thus, the thickness of the first protrusion structure 21 is appropriate, which is beneficial to the collection of photo-generated carriers while ensuring the reduction of optical parasitic absorption.

[0035] In one embodiment, a plurality of second recesses 31 are formed on the surface of the P-type doped layer 18 on the side away from the substrate layer 15, so that a second protrusion structure 22 is formed at the position of the P-type doped layer 18 corresponding to the gate line structure 19. The thickness b of the second protrusion structure 22 ranges from 35 nm to 45 nm. The thickness of the second protrusion structure 22 may be the distance from the side of the second protrusion structure 22 away from the substrate layer 15 to the side of the P-type doped layer 18 close to the substrate layer 15. The thickness b of the second protrusion structure 22 may be 35 nm, 40 nm, 45 nm, etc. Thus, the thickness of the second protrusion structure 22 is appropriate, which is beneficial to the collection of photo-generated carriers while ensuring the reduction of optical parasitic absorption.

[0036] In one embodiment, the distance c between the bottom surface of the first recess 30 on the side close to the substrate layer 15 and the N-type doped layer 17 on the side close to the substrate layer 15 ranges from 10 nm to 20 nm. The distance c between the bottom surface of the first recess 30 on the side close to the substrate layer 15 and the N-type doped layer 17 on the side close to the substrate layer 15 may be 10 nm, 20 nm, 15 nm, etc. The main reason for the low short-circuit current of the solar cell 10 is the optical parasitic effect generated by the doped layer 16 at the light-receiving surface and the backlight surface of the substrate 11 due to the use of amorphous silicon or microcrystalline silicon, which makes it difficult to collect photo-generated carriers at the amorphous silicon or microcrystalline silicon. The distance c between the bottom surface of the first recess 30 on the side close to the substrate layer 15 and the N-type doped layer 17 on the side close to the substrate layer 15 ranges from 10 nm to 20 nm. Thus, the thickness of the N-type doped layer 17 is relatively thin, which can reduce the dead layer, reduce optical parasitic absorption, reduce optical loss, thereby increasing the short-circuit current of the solar cell 10 and improving the light conversion efficiency of the solar cell 10.

[0037] In one embodiment, the distance d between the bottom surface of the second recess 31 close to the substrate layer 15 and the side of the P-type doped layer 18 close to the substrate layer 15 ranges from 20 nm to 30 nm. The distance d between the bottom surface of the second recess 31 close to the substrate layer 15 and the side of the P-type doped layer 18 close to the substrate layer 15 can be 20 nm, 25 nm, 30 nm, etc. The distance d between the bottom surface of the second recess 31 close to the substrate layer 15 and the side of the P-type doped layer 18 close to the substrate layer 15 ranges from 20 nm to 30 nm. In this way, the thickness of the P-type doped layer 18 is relatively thin, which can reduce the dead layer, reduce the optical parasitic absorption, reduce the optical loss, thereby increasing the short-circuit current of the solar cell 10 and improving the light conversion efficiency of the solar cell 10. Among them, the ranges in the embodiments of the present disclosure all include the end point values.

[0038] In one embodiment, the substrate 11 further includes two groups of amorphous silicon layers 23. The amorphous silicon layer 23 can be an intrinsic amorphous silicon layer. The two groups of amorphous silicon layers 23 are respectively disposed on opposite sides of the substrate layer 15, and the amorphous silicon layer 23 is located between the substrate layer 15 and the doped layer 16. The two groups of amorphous silicon layers 23 include a first amorphous silicon layer 24 and a second amorphous silicon layer 25, and the first amorphous silicon layer 24 and the second amorphous silicon layer 25 are respectively disposed on opposite sides of the substrate layer 15. Among them, the first amorphous silicon layer 24 is located between the N-type doped layer 17 and the substrate layer 15, and the second amorphous silicon layer 25 is located between the P-type doped layer 18 and the substrate layer 15. The thicknesses of the first amorphous silicon layer 24 and the second amorphous silicon layer 25 can be the same, and can both be 5 nm. Disposing the intrinsic amorphous silicon layer 23 on opposite sides of the substrate layer 15 is beneficial to improving the photoelectric conversion efficiency.

[0039] In one embodiment, the substrate 11 further includes two groups of conductive films 26, such as films made of TCO materials. The conductive film 26 can be a single layer or a stack. The two groups of conductive films 26 are respectively disposed on opposite sides of the substrate layer 15, and the conductive film 26 is located on the side of the doped layer 16 away from the substrate layer 15. Among them, the electrode 12 is formed on the outer surface of the conductive film 26. The two groups of conductive films 26 include a first conductive film 27 and a second conductive film 28, and the first conductive film 27 and the second conductive film 28 are respectively disposed on opposite sides of the substrate layer 15. Among them, the first conductive film 27 is located on the side of the N-type doped layer 17 away from the substrate layer 15, and the second conductive film 28 is located on the side of the P-type doped layer 18 away from the substrate layer 15. Disposing the conductive films 26 on opposite sides of the substrate layer 15 is beneficial to the lateral transport of photo-generated carriers, thereby ensuring the lateral transport ability of photo-generated carriers.

[0040] In this embodiment, the thickness a of the first convex structure 21 is 30 nm, and the distance c between the bottom surface of the first concave portion 30 close to the substrate layer 15 and the substrate layer 15 on the side of the N-type doping layer 17 is 15 nm. The thickness b of the second convex structure 22 is 40 nm, and the distance d between the bottom surface of the second concave portion 31 close to the substrate layer 15 and the substrate layer 15 on the side of the P-type doping layer 18 is 25 nm. And each gate line structure 19 is correspondingly provided with a convex structure 20, and the width of the convex structure 20 is 120 μm. Thus, in about 7.65% of the area, the thickness of the doping layer is increased by 5 nm compared with the doping layer in the related art, and in about 92.35% of the area, the thickness of the doping layer is reduced by 10 nm compared with the doping layer in the related art. Overall, the doped layer 16 made of microcrystalline silicon or amorphous silicon is thinned, reducing the optical parasitic absorption. And because the convex structure 20 is formed at the position of the doped layer 16 corresponding to the gate line structure 19, the thickness at the corresponding position of the gate line structure 19 is increased, ensuring the electric field potential energy of the solar cell 10.

[0041] The thickness of the N-type doping layer of the solar cell in the related art is 20 nm, and the thickness of the P-type doping layer is 35 nm. Table 1 is a performance comparison between the solar cell 10 of the embodiment of the present disclosure and the solar cell in the above related art.

[0042] Efficiency Eta Open-circuit voltage Voc Short-circuit current Isc Fill factor FF Related art 24.60 0.7459 8.741 83.21 This embodiment 24.77 0.7455 8.802 83.24

[0043] Table 1

[0044] As can be seen from Table 1, on the basis of ensuring the open-circuit voltage Voc, the short-circuit current Isc of the solar cell 10 in this embodiment is increased by 61 mA, and the overall efficiency is increased by 0.17%. A plurality of concave portions 29 are formed on the surface of the doped layer 16 of the solar cell 10 in this embodiment away from the substrate layer 15, so that the convex structure 20 is formed at the position of the doped layer 16 corresponding to the gate line structure 19. Thus, on the basis of ensuring the open-circuit voltage Voc, the thickness of the doped layer 16 at the position of the non-gate line structure can be thinned, making the thickness of the doped layer 16 relatively thin, thereby reducing the optical parasitic absorption, increasing the short-circuit current Isc by 61 mA, and increasing the overall efficiency by 0.17%.

[0045] See Figure 2 As shown, the embodiment of the present disclosure also provides a preparation method of a solar cell 10, and the preparation method of the solar cell 10 includes steps S101 to S109.

[0046] In step S101, the substrate layer 15 is subjected to texturing and cleaning treatments. Thus, the light trapping effect of the substrate layer 15 can be improved and the reflection can be reduced.

[0047] In step S102, amorphous silicon layers 23 are deposited on both sides of the etched and cleaned substrate layer 15 to form a first amorphous silicon layer 24 and a second amorphous silicon layer 25. The amorphous silicon layers 23 can be deposited on both sides of the substrate layer 15 by chemical vapor deposition. In this embodiment, amorphous silicon layers 23 with a thickness of 5 nm can be deposited. The substrate layer 15 can be an N-type single crystal silicon. Intrinsic amorphous silicon 23a-Si:H can be deposited on the surface of the N-type single crystal silicon, and a large amount of H is used to strongly passivate the surface of the silicon wafer.

[0048] In step S103, an N-type doped layer 17 is deposited on the side of the first amorphous silicon layer 24 away from the substrate layer 15, and a P-type doped layer 18 is deposited on the side of the second amorphous silicon layer 25 away from the substrate layer 15. The thickness of the deposited N-type doped layer 17 ranges from 25 nm to 35 nm, and the thickness of the deposited P-type doped layer 18 ranges from 35 nm to 45 nm. The substrate layer 15 can be an N-type single crystal silicon. In this way, the N-type doped layer 17 can form an N+ layer with the N-type single crystal silicon to improve the efficiency of the solar cell, and the P-type doped layer 18 can form a PN junction with the N-type single crystal silicon, which is the core of the battery power generation.

[0049] In step S104, an alkali-resistant and acid-intolerant mask is printed on the surface of the N-type doped layer 17 away from the substrate layer 15 and the surface of the P-type doped layer 18 away from the substrate layer 15. The alkali-resistant and acid-intolerant mask can be printed on the surface of the N-type doped layer 17 away from the substrate layer 15 and the surface of the P-type doped layer 18 away from the substrate layer 15 by screen printing. Among them, the shape of the mask is the same as the shape of the grid line structure 19. The width of the mask can range from 100 μm to 150 μm.

[0050] In step S105, the N-type doped layer 17 and the P-type doped layer 18 are cleaned with an alkaline solution. In this way, the area of the doped layer 16 not covered by the mask will react with the alkaline solution to reduce the thickness of the area of the doped layer 16 not covered by the mask, so as to form a doped layer 16 with a convex structure 20. Among them, the alkaline solution can be a NaOH solution with a mass fraction ranging from 0.075% to 0.2%. During the cleaning process, dust can be removed to improve the overall yield. And the alkaline solution can preferentially corrode the originally non-dense groups, which can improve the quality of the N-type doped layer 17 and the P-type doped layer 18.

[0051] In step S106, the N-type doped layer 17 and the P-type doped layer 18 are cleaned with an acidic solution to remove the mask. Among them, the acidic solution can be an HCl solution with a mass fraction ranging from 1% to 2%, or an HF solution with a mass fraction ranging from 2.5% to 5%.

[0052] In step S107, the cleaned N-type doped layer 17 and P-type doped layer 18 are dried to remove the moisture on the surface.

[0053] In step S108, a first conductive thin film 27 is deposited on the side of the N-type doped layer 17 away from the substrate layer 15, and a second conductive thin film 28 is deposited on the side of the P-type doped layer 18 away from the substrate layer 15.

[0054] In step S109, a gate line structure 19 is formed on the side of the first conductive thin film 27 away from the substrate layer 15 and on the side of the second conductive thin film 28 away from the substrate layer 15. The low-temperature silver paste can be printed on the side of the first conductive thin film 27 away from the substrate layer 15 and on the side of the second conductive thin film 28 away from the substrate layer 15 by screen printing and sintered to form the gate line structure 19.

[0055] In another embodiment of the method for manufacturing the solar cell 10 described above, steps S103 to S107 can also be replaced as follows: a hollow baffle is used to partially block the deposition of the N-type doped layer 17 on the side of the first amorphous silicon layer 24 away from the substrate layer 15, and a hollow baffle is used to partially block the deposition of the P-type doped layer 18 on the side of the second amorphous silicon layer 25 away from the substrate layer 15. Since the ions have a certain mean free path during the deposition process, even after being partially blocked by the hollow baffle, the deposition can still be carried out normally over the entire surface, but the film thickness in the blocked area will be thinner than that in the unblocked area. In this way, the doped layer 16 with the convex structure 20 can also be formed.

[0056] The present disclosure also provides a photovoltaic module, which includes a plurality of solar cells 10. The plurality of solar cells 10 can be connected in series. It should be noted that the descriptions of the solar cell 10 in the above embodiments and implementation manners are equally applicable to the photovoltaic module of the embodiments of the present disclosure.

[0057] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.

Claims

1. A solar cell, characterized in that, The invention comprises a substrate and two groups of electrodes, wherein the two groups of electrodes are respectively formed on two opposite sides of the substrate; the electrodes comprise a plurality of grid line structures arranged at intervals; the substrate comprises a substrate layer and two groups of doping layers respectively arranged on two opposite sides of the substrate layer; A plurality of recessed portions are formed on a surface of the doping layer away from the substrate layer, and the recessed portions are staggered with the gate line structures so that a convex structure is formed at a position of the doping layer corresponding to the gate line structure.

2. The solar cell according to claim 1, characterized in that, The protruding structures extend along the length direction of the gate line structure, and a plurality of the protruding structures are arranged at intervals in the width direction of the gate line structure.

3. The solar cell according to claim 1, characterized in that, The two groups of doping layers include an N-type doping layer and a P-type doping layer, and the N-type doping layer and the P-type doping layer are respectively arranged on two opposite sides of the substrate layer.

4. The solar cell according to claim 3, characterized in that, A plurality of first recessed portions are formed on a surface of the N-type doped layer away from the substrate layer, so that a first convex structure is formed at a position of the N-type doped layer corresponding to the gate line structure; the thickness of the first convex structure ranges from 25 nm to 35 nm; and / or A plurality of second recessed portions are formed on the surface of the P-type doped layer away from the substrate layer, so that a second convex structure is formed at the position of the P-type doped layer corresponding to the gate line structure; the thickness of the second convex structure ranges from 35nm to 45nm.

5. The solar cell according to claim 3, characterized in that, A plurality of first recessed portions are formed on the surface of the N-type doped layer away from the substrate layer, so that a first convex structure is formed at a position of the N-type doped layer corresponding to the gate line structure; a distance between a bottom surface of the first recessed portion close to the substrate layer and a side of the N-type doped layer close to the substrate layer is in a range of 10 nm to 20 nm; and / or A plurality of second recessed portions are formed on the surface of the P-type doped layer away from the substrate layer, so that a second convex structure is formed at the position of the P-type doped layer corresponding to the gate line structure; the distance between the bottom surface of the second recessed portion close to the substrate layer and the P-type doped layer close to the substrate layer is in a range of 20nm to 30nm.

6. The solar cell according to claim 3, wherein, The N-type doping layer is arranged on the front side of the substrate layer, and the P-type doping layer is arranged on the back side of the substrate layer; the thickness of the N-type doping layer is smaller than the thickness of the P-type doping layer.

7. The solar cell according to claim 1, wherein The width of the protrusion structure ranges from 100um to 150um.

8. The solar cell according to claim 1, characterized in that, The central axis of the protrusion structure is arranged to coincide with the central axis of the corresponding grid line structure.

9. The solar cell according to claim 1, wherein The substrate further comprises two groups of amorphous silicon layers, the two groups of amorphous silicon layers are respectively arranged on opposite sides of the substrate layer, and the amorphous silicon layers are located between the substrate layer and the doping layer; and / or The substrate also includes two groups of conductive films, which are respectively arranged on opposite sides of the substrate layer, and the conductive films are located on a side of the doping layer away from the substrate layer; wherein the electrode is formed on the outer surface of the conductive film.

10. The solar cell according to claim 1, wherein The solar cell is a heterojunction cell.

11. A photovoltaic module, characterized in that, The photovoltaic module comprises a plurality of solar cells according to any one of claims 1 to 10.

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