Photovoltaic cell, module, and system

Abstract

The present disclosure provides a photovoltaic cell, a module, and a system. The photovoltaic cell comprises: a silicon substrate; a first transport layer; a second transport layer; a laser absorption protective layer; a first conductive layer; and a second conductive layer, the second conductive layer covering the laser absorption protective layer and an electrode contact region of the second transport layer, the second conductive layer being provided with an insulating trench, and a warped portion being formed at an edge of an opening of the insulating trench. The photovoltaic cell of the present disclosure enables an increase in cell production yield.

Description

Photovoltaic cells, modules, and systems

[0001] Cross-reference to related applications

[0002] The present disclosure refers to the Chinese Patent Application No. 202422407194.9 entitled "A Back Contact Solar Cell, Cell Module and Photovoltaic System" filed on September 30, 2024, which is incorporated by reference in its entirety. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of solar cells, in particular to a photovoltaic cell, module and system. BACKGROUND

[0004] Solar energy is inexhaustible renewable energy, which is of great significance to environmental protection. The effective utilization of solar energy has become the consensus of mankind. The utilization of solar energy, especially photovoltaic power generation technology, is the most promising renewable energy technology. Solar cells have the advantages of low energy consumption, abundant raw materials, no pollution, and easy mass production, and have realized industrialization and are widely used in ground photovoltaic power stations, building integrated photovoltaic, roof power stations and other fields. Among them, the back contact (BC) solar cell is a research hotspot in the industry. The back surface of the photovoltaic cell is provided with an electron selective transport layer and a hole selective transport layer. Its biggest feature is that the metal electrode is located on the back surface of the cell, and the front surface is not blocked by the metal electrode, which improves the utilization of light, so it has higher short-circuit current and conversion efficiency.

[0005] In the related art, for a photovoltaic cell, especially an HBC cell, a conductive layer is usually deposited on the collector to solve the problem of poor contact between the metal grid line and the transport layer. Due to the special structure of the photovoltaic cell, the PN regions are staggered adjacent to each other. After the deposition of the conductive layer, the PN regions are directly connected, causing a short circuit and leakage of the circuit. Therefore, it is usually necessary to laser etch the conductive layer at the PN adjacent position to form an insulating groove to form a leakage protection. However, in the actual production process, due to the problem of the laser itself, the conductive layer on the inner wall of the insulating groove cannot be completely removed, and the conductive layer at the edge of the groove opening is too flat. The conductive layer is easy to cover the inner wall of the insulating groove, which easily causes the conductive layer of the PN region to be connected and leak, resulting in low production yield.

[0006] DISCLOSURE

[0007] The present disclosure provides a photovoltaic cell, which aims to solve the problem of low production yield caused by the leakage of the conductive layer of the PN region in the related art photovoltaic cell.

[0008] The present disclosure is implemented in this way, which provides a photovoltaic cell, comprising:

[0009] a silicon substrate, the silicon substrate comprising a back light surface, the back light surface of the silicon substrate being provided with a first region and a second region;

[0010] a first transmission layer disposed in the first region;

[0011] a second transmission layer disposed in the second region, the second transmission layer having a different doping type than the first transmission layer;

[0012] a laser absorption protective layer disposed on a side of the second transmission layer distal to the backplane and exposing the electrode contact region of the second transmission layer;

[0013] a first conductive layer disposed on a side of the first transmission layer distal to the backplane;

[0014] a second conductive layer disposed on a side of the laser absorption protective layer distal to the backplane, the second conductive layer covering the electrode contact region of the laser absorption protective layer and the second transmission layer, the second conductive layer having an insulating groove disposed in a region proximal to the first conductive layer, the second conductive layer having a warping portion formed at an edge of the insulating groove, the warping portion warping from an inner side of the insulating groove to an outer side of the insulating groove.

[0015] In some embodiments, further comprising:

[0016] a first electrode disposed in the first region and in contact with the first conductive layer;

[0017] a second electrode disposed in the second region and in contact with the second conductive layer corresponding to the electrode contact region, the insulating groove being disposed between the first electrode and the second electrode.

[0018] In some embodiments, the first transmission layer includes a first passivation layer and a first doped layer stacked in sequence on the backplane, the first conductive layer being disposed on a side of the first doped layer distal to the silicon substrate;

[0019] the second transmission layer includes a second passivation layer and a second doped layer stacked in sequence on the backplane, the first doped layer and the second doped layer having different doping types, the laser absorption protective layer being disposed on a side of the second doped layer distal to the silicon substrate.

[0020] In some embodiments, the first passivation layer and the second passivation layer are both amorphous silicon; the first doped layer and the second doped layer are both doped amorphous silicon or doped microcrystalline silicon.

[0021] Alternatively, the first passivation layer and the second passivation layer are both silicon oxide; the first doped layer and the second doped layer are doped polysilicon or doped microcrystalline silicon.

[0022] Alternatively, the first passivation layer and the second passivation layer are amorphous silicon and silicon oxide, respectively; the first doped layer and the second doped layer are doped polysilicon and doped microcrystalline silicon, respectively.

[0023] In some embodiments, the laser absorption protective layer includes:

[0024] an insulating layer disposed on a side of the second transport layer away from the silicon substrate and exposing the electrode contact area of the second transport layer;

[0025] a laser absorption layer disposed on a side of the insulating layer away from the silicon substrate and exposing the electrode contact area of the second transport layer.

[0026] In some embodiments, the insulating layer is one or a stack of at least two of a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, and a silicon carbide layer.

[0027] In some embodiments, the laser absorption layer is one or a stack of at least two of an amorphous silicon layer, a nanocrystalline silicon layer, a microcrystalline silicon layer, and a polycrystalline silicon layer.

[0028] In some embodiments, the laser absorption layer comprises:

[0029] a first laser absorption layer disposed on a side of the insulating layer away from the silicon substrate and exposing the electrode contact area;

[0030] a second laser absorption layer disposed on a side of the first laser absorption layer away from the silicon substrate and exposing the electrode contact area.

[0031] In some embodiments, the first laser absorption layer is an intrinsic amorphous silicon layer and the second laser absorption layer is a doped amorphous silicon layer.

[0032] In some embodiments, the insulating trench at least partially penetrates the laser absorption layer.

[0033] In some embodiments, the total thickness of the laser absorption layer is 5-50 nm.

[0034] In some embodiments, the thickness of the second conductive layer is 40-150 microns.

[0035] In some embodiments, the height of the warped portion is 0.2-2 microns.

[0036] In some embodiments, the included angle B between the warped portion and the side of the second conductive layer close to the silicon substrate is 15-150°.

[0037] In some embodiments, the included angle B between the warped portion and the side of the second conductive layer close to the silicon substrate is 90-150°.

[0038] In some embodiments, the silicon substrate further comprises a light-facing surface disposed opposite to the back-lighting surface, and the photovoltaic cell further comprises:

[0039] a front passivation layer disposed on the light-facing surface;

[0040] a reflection-reducing film layer disposed on a side of the front passivation layer away from the silicon substrate.

[0041] The present disclosure also provides a photovoltaic module comprising the photovoltaic cell described above.

[0042] The present disclosure also provides a photovoltaic system comprising the photovoltaic module described above.

[0043] The photovoltaic cell provided by the present disclosure sets a laser absorption protective layer on the side of the second transmission layer away from the back surface, and sets a second conductive layer on the side of the laser absorption protective layer away from the back surface. When forming an insulating groove by laser etching on the second conductive layer, the laser absorption protective layer expands due to heat absorption, and the laser absorption protective layer pushes the edge part of the second conductive layer close to the slot of the insulating groove outward to form a warping part, so as to avoid the second conductive layer residue adhering to the inner wall of the insulating groove to form a leakage path with the first conductive layer, thereby improving the production yield of the cell. Moreover, the warping part formed by the edge of the slot of the insulating groove can block the damage to the second conductive layer and the silicon substrate in the subsequent wet cleaning process, and can further improve the production yield of the cell. BRIEF DESCRIPTION OF DRAWINGS

[0044] Fig. 1 is a schematic diagram of a photovoltaic cell provided by an embodiment of the present disclosure;

[0045] Fig. 2 is a schematic diagram of a partial structure of a photovoltaic cell provided by an embodiment of the present disclosure;

[0046] Fig. 3 is an SEM diagram of a warping part of a second conductive layer of a photovoltaic cell provided by an embodiment of the present disclosure.

[0047] Legend: 1, silicon substrate; 2, first transmission layer; 21, first passivation layer; 22, first doped layer; 3, second transmission layer; 31, second passivation layer; 32, second doped layer; 4, laser absorption protective layer; 41, insulating layer; 42, first laser absorption layer; 43, second laser absorption layer; 5, first conductive layer; 6, second conductive layer; 61, insulating groove; 62, warping part; 7, first electrode; 8, second electrode; 9, front passivation layer; 10, anti-reflection film layer; 111, first region; 112, second region. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure, and are not used to limit the present disclosure.

[0049] The photovoltaic cell provided by the embodiment of the present disclosure sets a laser absorption protective layer on the side of the second transmission layer far from the back light surface, and sets the second conductive layer on the side of the laser absorption protective layer far from the back light surface. When the laser etching process forms the insulating groove on the second conductive layer, the laser absorption protective layer expands due to heat absorption, and the laser absorption protective layer pushes the edge part of the second conductive layer close to the insulating groove outward to form a warping part, so as to avoid the second conductive layer residue from adhering to the inner wall of the insulating groove to form a leakage path with the first conductive layer, thereby improving the production yield of the cell. Moreover, the warping part formed by the edge of the insulating groove can block the damage to the second conductive layer and the silicon substrate in the wet cleaning process, and can further improve the production yield of the cell.

[0050] Please refer to FIG. 1-2, the embodiment of the present disclosure provides a photovoltaic cell, comprising:

[0051] The silicon substrate 1 includes a back light surface, and the back light surface is provided with a first area 111 and a second area 112;

[0052] The first transmission layer 2 is arranged in the first area 111;

[0053] The second transmission layer 3 is arranged in the second area 112, and the second transmission layer 3 is different from the first transmission layer 2 in the doping type;

[0054] The laser absorption protective layer 4 is arranged on the side of the second transmission layer 3 far from the back light surface, and exposes the electrode contact area of the second transmission layer 3;

[0055] The first conductive layer 5 is arranged on the side of the first transmission layer 2 far from the back light surface;

[0056] The second conductive layer 6 is arranged on the side of the laser absorption protective layer 4 far from the back light surface, and the second conductive layer 6 covers the laser absorption protective layer 4 and the electrode contact area. The area close to the first conductive layer 5 of the second conductive layer 6 is provided with an insulating groove 61, and the second conductive layer 6 forms a warping part 62 warping from the inside of the insulating groove 61 to the outside of the insulating groove 61 on the edge of the insulating groove 61.

[0057] In the embodiment of the present disclosure, the area in the back light surface located on the right side of the dashed line L is the first area 111, and the area in the back light surface located on the left side of the dashed line L is the second area 112. The first area 111 and the second area 112 are alternately distributed along the first direction. It should be noted that the dashed line L does not actually exist in the photovoltaic cell, and this is only a schematic representation of the first area 111 and the second area 112.

[0058] One of the first region 111 and the second region 112 is a P region, and the other is an N region. For example, the first region 111 is a P region, and the second region 112 is an N region; or the first region 111 is an N region, and the second region 112 is a P region. The first region 111 and the second region 112 are alternately arranged in sequence on the back surface of the silicon substrate 1.

[0059] In the embodiment of the present disclosure, the silicon substrate 1 includes a light-facing surface 12 and a back surface opposite to the light-facing surface 12. The light-facing surface 12 is a surface of the silicon substrate 1 facing the sunlight when the photovoltaic cell is working, and the back surface is a surface of the silicon substrate 1 away from the sunlight when the photovoltaic cell is working.

[0060] In the embodiment of the present disclosure, the silicon substrate 1 can be a silicon substrate, and the doping type of the silicon substrate can be N-type doping or P-type doping, and the doping type of the silicon substrate is not limited. The front surface and the back surface of the silicon substrate are oppositely arranged. The doping types of the first transport layer 2 and the second transport layer 3 are different, that is, one of the two is N-type doping, and the other is P-type doping.

[0061] In the embodiment of the present disclosure, the photovoltaic cell is provided by arranging a laser absorption protective layer 4 on a side of the second transport layer 3 away from the back surface, and arranging the second conductive layer 6 on a side of the laser absorption protective layer 4 away from the back surface. When the laser absorption protective layer 4 is expanded by absorbing heat in the process of laser etching the second conductive layer 6 to form an insulating groove 61, the laser absorption protective layer 4 pushes the part of the second conductive layer 6 close to the edge of the slot of the insulating groove 61 outward to form a warping part 62, thereby avoiding the second conductive layer 6 residues at the position of the insulating groove 61 from being attached to the inside of the insulating groove 61 to form a leakage path with the first conductive layer 5, that is, preventing the conductive layers of the P region and the N region from being connected to cause leakage, thereby improving the production yield of the cell. Moreover, the warping part 62 formed by the edge of the slot of the insulating groove 61 can block the etching solution in the wet cleaning process, thereby avoiding the etching solution from damaging the second conductive layer 6 and the silicon substrate 1, and further improving the production yield of the cell.

[0062] In the embodiment of the present disclosure, when the laser absorption protective layer 4 is expanded by absorbing heat in the process of laser etching the second conductive layer 6 to form an insulating groove 61, the second conductive layer 6 attached to the inner wall of the insulating groove 61 is pushed outward by the laser absorption protective layer 4 to separate from the laser absorption protective layer 4, so that the second conductive layer 6 attached to the inner wall of the insulating groove 61 is warped in a direction away from the laser absorption protective layer 4 to form a warping part 62, thereby avoiding the second conductive layer 6 from being attached to the inner wall of the insulating groove 61, and preventing the second conductive layer 6 residues from being attached to the inside of the insulating groove 61 to form a leakage path with the first conductive layer 5. As shown in FIG. 3, the warping part 62 of the second conductive layer 6 at the edge of the slot of the insulating groove 61 can be in a circular arc shape, an inclined surface shape, or an irregularly curled shape, and the warping part 62 can also simultaneously include a circular arc shape, an inclined surface shape, or an irregularly curled shape.

[0063] As some embodiments of the present disclosure, further comprising:

[0064] The first electrode 7 arranged in the first region 111 is in contact with the first conductive layer 5.

[0065] The second electrode 8 arranged in the second region 112 is in contact with the second conductive layer 6 corresponding to the electrode contact region, and the insulating groove 61 is located between the first electrode 7 and the second electrode 8.

[0066] In the embodiment, the polarities of the first electrode 7 and the second electrode 8 are opposite, that is, one of the first electrode 7 and the second electrode 8 is a positive electrode, and the other is a negative electrode. The first electrode 7 is in contact with the first transmission layer 2 by the first conductive layer 5, and the second electrode 8 is in contact with the second transmission layer 3 by the second conductive layer 6. Among them, the first conductive layer 5 and the second conductive layer 6 are insulated and separated by the insulating groove 61 to prevent the first conductive layer 5 and the second conductive layer 6 from conducting and leaking.

[0067] As some embodiments of the present disclosure, the first transmission layer 2 comprises a first passivation layer 21 and a first doped layer 22 arranged in the backlight surface in sequence, and the first conductive layer 5 is arranged on the side of the first doped layer 22 away from the silicon substrate 1.

[0068] The second transmission layer 3 comprises a second passivation layer 31 and a second doped layer 32 arranged in the backlight surface in sequence, the doping types of the first doped layer 22 and the second doped layer 32 are different, and the laser absorption protection layer 4 is arranged on the side of the second doped layer 32 away from the silicon substrate 1.

[0069] In the embodiment, the doping types of the first doped layer 22 and the second doped layer 32 are different, that is, one of them is an N-type doped layer, and the other is a P-type doped layer. Among them, the materials of the first passivation layer 21 and the second passivation layer 31 can be the same or different. The materials of the first doped layer 22 and the second doped layer 32 can be the same or different. The first electrode 7 is in contact with the first doped layer 22 by the first conductive layer 5, and the second electrode 8 is in contact with the second doped layer 32 by the second conductive layer 6, thereby improving the contact effect of the electrode and the doped layer.

[0070] As some embodiments of the present disclosure, the first passivation layer 21 and the second passivation layer 31 are both amorphous silicon; the first doped layer 22 and the second doped layer 32 are both doped amorphous silicon or doped microcrystalline silicon;

[0071] Or, the first passivation layer 21 and the second passivation layer 31 are both silicon oxide; the first doped layer 22 and the second doped layer 32 are doped polycrystalline silicon or doped microcrystalline silicon;

[0072] Or, the first passivation layer 21 and the second passivation layer 31 are amorphous silicon or silicon oxide respectively, and the first doped layer 22 and the second doped layer 32 are doped polycrystalline silicon and doped microcrystalline silicon respectively.

[0073] In some embodiments, the first passivation layer 21 and the second passivation layer 31 are made of amorphous silicon, and the first doped layer 22 and the second doped layer 32 are made of doped amorphous silicon, or doped microcrystalline silicon. In this case, the photovoltaic cell is a HBC (Heterojunction Back Contact) cell, which has the advantages of high open-circuit voltage, low process temperature, excellent temperature characteristics, etc. In some embodiments, the first passivation layer 21 and the second passivation layer 31 are made of silicon oxide, and the first doped layer 22 and the second doped layer 32 are made of doped polysilicon, or doped microcrystalline silicon. In this case, the photovoltaic cell is a TBC (Tunnel Oxide Back Contact) cell, which also has the advantages of high open-circuit voltage, low process temperature, excellent temperature characteristics, etc. In some embodiments, the first passivation layer 21 and the second passivation layer 31 are made of amorphous silicon or silicon oxide, and the first doped layer 22 and the second doped layer 32 are made of doped polysilicon, or doped microcrystalline silicon. In this case, the photovoltaic cell is a HTBC (Heterojunction Tunnel Oxide Back Contact) cell, which also has the advantages of high open-circuit voltage, low process temperature, excellent temperature characteristics, etc.

[0074] In some embodiments, the laser absorption protective layer 4 comprises:

[0075] The insulating layer 41 is arranged on the side of the second transport layer 3 away from the silicon substrate 1, and exposes the electrode contact area of the second transport layer 3.

[0076] The laser absorption layer is arranged on the side of the insulating layer 41 away from the silicon substrate 1, and exposes the electrode contact area of the second transport layer 3.

[0077] In this embodiment, the laser absorption layer and the insulating layer 41 form a second opening on the side of the second transport layer 3 away from the silicon substrate 1, and the second opening exposes the area of the second transport layer 3 as the electrode contact area of the second electrode 8. The second electrode 8 is in contact with the second conductive layer 6 of the electrode contact area to collect the carriers in the second transport layer 3.

[0078] In this embodiment, the laser absorption layer can have a single-layer, double-layer or more-layer structure. The insulating medium layer separates the laser absorption layer from the second transport layer 3 to further protect the second transport layer 3.

[0079] In some embodiments, the insulating groove 61 at least partially penetrates the laser absorption layer.

[0080] In the embodiment, the insulating groove 61 can only partially penetrate the laser absorption layer, or can completely penetrate the laser absorption layer, that is, the depth of the insulating groove 61 is at least greater than the thickness of the second conductive layer 6. In addition, the insulating groove 61 can also at least partially penetrate the insulating layer 41. In some embodiments, the insulating groove 61 simultaneously penetrates the laser absorption layer and the insulating layer 41, that is, the depth of the insulating groove 61 is greater than the total thickness of the second conductive layer 6 and the laser absorption layer, so that the removal of the second conductive layer 6 in the area of the insulating groove 61 is more complete.

[0081] In some embodiments, the insulating layer 41 is one of a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a silicon carbide layer, or a stack of at least two of them.

[0082] In the embodiment, the insulating layer 41 can be one of a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a silicon carbide layer, or a stack of at least two of them.

[0083] In some embodiments, the laser absorption layer is one of an amorphous silicon layer, a nanocrystalline silicon layer, a microcrystalline silicon layer, or a polycrystalline silicon layer, or a stack of at least two of them, which can achieve good laser absorption effect.

[0084] In the embodiment, the laser absorption layer can be one of an amorphous silicon layer, a nanocrystalline silicon layer, a microcrystalline silicon layer, or a polycrystalline silicon layer, or a stack of at least two of them.

[0085] In some embodiments, the laser absorption layer includes:

[0086] The first laser absorption layer 42 is arranged on the side of the insulating layer 41 away from the silicon substrate 1 and exposes the electrode contact area.

[0087] The second laser absorption layer 43 is arranged on the side of the first laser absorption layer 42 away from the silicon substrate 1 and exposes the electrode contact area.

[0088] In the embodiment, the laser absorption layer is arranged to include the first laser absorption layer 42 and the second laser absorption layer 43, and the two layers of laser absorption layers expand by absorbing heat at the same time, and the two layers of laser absorption layers push the second conductive layer 6 close to the edge of the insulating groove 61 outward to form a warping part 62, which can better avoid the second conductive layer 6 residue at the position of the insulating groove 61 from adhering to the inside of the insulating groove 61, thereby further improving the production yield of the battery.

[0089] In some embodiments, the first laser absorption layer 42 is an intrinsic amorphous silicon layer, and the second laser absorption layer 43 is a doped amorphous silicon layer.

[0090] In the embodiment, the laminated structure formed by the intrinsic amorphous silicon layer and the doped amorphous silicon layer can further improve the back surface passivation effect of the photovoltaic cell and improve the cell efficiency. Moreover, the intrinsic amorphous silicon layer is ingeniously used as the first laser absorption layer 42, and the doped amorphous silicon layer is used as the second laser absorption layer 43, without separately arranging a laser absorption layer, the passivation effect and the laser absorption function of the intrinsic amorphous silicon layer and the doped amorphous silicon layer are realized, and the production cost can be reduced; when the laser etching forms the insulating groove 61, the intrinsic amorphous silicon layer and the doped amorphous silicon layer are used to simultaneously push the second conductive layer 6 close to the edge of the slot of the insulating groove 61 outward to form the warping part 62, so as to avoid the residues of the second conductive layer 6 at the position of the insulating groove 61 from being attached to the inside of the insulating groove 61, thereby further improving the cell production yield.

[0091] In some embodiments, the first laser absorption layer 42 is an intrinsic amorphous silicon layer, and the second laser absorption layer 43 is a doped amorphous silicon layer; the laser absorption layer can further include a third laser absorption layer arranged on the second laser absorption layer 43.

[0092] In the embodiment, the intrinsic amorphous silicon layer and the doped amorphous silicon layer are used as the second laser absorption layer 43, and a third laser absorption layer is further arranged, so as to further improve the laser absorption effect of the laser absorption layer, which is beneficial to improving the effect of pushing the part of the second conductive layer 6 close to the insulating groove 61 outward to form the warping part 62. The third laser absorption layer can be one or a laminated structure of a silicon carbide layer and a silicon nitride layer.

[0093] In some embodiments, referring to FIG. 2 again, the height H of the warping part 62 is 0.2-2 microns. The height H of the warping part 62 is the vertical distance from the top of the warping part 62 to the outer surface of the second conductive layer 6.

[0094] In the embodiment, the warping part 62 is distributed along the edge of the insulating groove 61, the height H of the warping part 62 is uniformly or non-uniformly arranged, and the height H of the warping part 62 is in the range of 0.2-2 microns, so as to as far as possible ensure that the part of the second conductive layer 6 close to the edge of the insulating groove 61 is pushed outward to form the warping part 62, and the warping part 62 formed at the edge of the insulating groove 61 can effectively block the damage to the second conductive layer 6 and the silicon substrate 1 in the subsequent wet cleaning process, and the cell production yield can be further improved.

[0095] In some embodiments, the included angle B between the warping part 62 and the side of the second conductive layer 6 close to the silicon substrate 1 is 15-150°.

[0096] In the embodiment, the warping portions 62 are distributed along the edge of the insulating groove 61, and the included angle B between the warping portions 62 and the second conductive layer 6 close to the silicon substrate 1 is in the range of 15-150°, which ensures that the edge portion of the second conductive layer 6 close to the insulating groove 61 is warped outward as much as possible to form the warping portions 62, and the warping portions 62 are beneficial to block the damage to the second conductive layer 6 and the silicon substrate 1 in the subsequent wet cleaning process.

[0097] In some embodiments, the included angle B between the warping portions 62 and the second conductive layer 6 close to the silicon substrate 1 is 90-150°.

[0098] In the embodiment, the included angle B between the warping portions 62 and the second conductive layer 6 close to the silicon substrate 1 is in the range of 90-150°, which ensures that the edge portion of the second conductive layer 6 close to the insulating groove 61 is warped outward as much as possible, and the warping portions 62 have good effect of blocking the damage to the second conductive layer 6 and the silicon substrate 1 in the subsequent wet cleaning process.

[0099] In some embodiments, the total thickness of the laser absorption layer is 5-50 nanometers, which can better ensure the warping degree of the warping portions 62.

[0100] In the embodiment, the total thickness of the laser absorption layer is 5-50 nanometers; when the laser absorption layer includes the first laser absorption layer 42 and the second laser absorption layer 43, the total thickness of the first laser absorption layer 42 and the second laser absorption layer 43 is 5-50 nanometers. The total thickness of the laser absorption layer is 5-50 nanometers, which is beneficial to the laser absorption layer to push the edge portion of the second conductive layer 6 in the insulating groove 61 outward when the insulating groove 61 is formed by laser etching.

[0101] In some embodiments, the thickness of the second conductive layer 6 is 40-150 micrometers, which is beneficial to the curling deformation of the second conductive layer 6 and to the edge portion of the second conductive layer 6 close to the insulating groove 61 being pushed outward by the laser absorption layer to form the warping portions 62 when the edge portion is etched by laser.

[0102] In some embodiments, the first conductive layer 5 and / or the second conductive layer 6 is a transparent conductive metal oxide.

[0103] In the embodiment, the materials of the first conductive layer 5 and the second conductive layer 6 can be the same or different. In some implementations, the materials of the first conductive layer 5 and the second conductive layer 6 are the same, which facilitates the one-time processing and preparation of the first conductive layer 5 and the second conductive layer 6.

[0104] In some embodiments, the first conductive layer 5 and the second conductive layer 6 are one of ITO film, AZO film, and IZO film or a stack of at least two of them.

[0105] In some embodiments, the photovoltaic cell further includes:

[0106] a front passivation layer 9 disposed on the light-receiving surface 12;

[0107] a second anti-reflective film layer 10 disposed on the side of the front passivation layer 9 away from the silicon substrate.

[0108] In this embodiment, the front passivation layer 9 is disposed on the light-receiving surface 12 of the silicon substrate 1 to improve the front passivation effect and improve the cell efficiency. Meanwhile, the second anti-reflective film layer 10 is used to reduce the solar reflectivity of the photovoltaic cell, which is conducive to further improving the cell efficiency.

[0109] In some embodiments, the front passivation layer 9 is an intrinsic amorphous silicon layer or an Al2O3 layer, and the second anti-reflective film layer 10 is a SiN x layer. Of course, the materials of the front passivation layer 9 and the second anti-reflective film layer 10 are not limited to this.

[0110] The photovoltaic assembly provided by the embodiments of the present disclosure includes the photovoltaic cell described above. It should be noted that the photovoltaic assembly has the same or similar beneficial effects as the photovoltaic cell, and the related parts between the two can be referred to each other. In order to avoid repetition, it will not be described here.

[0111] The photovoltaic system provided by the embodiments of the present disclosure includes the photovoltaic assembly described above. It should be noted that the photovoltaic system has the same or similar beneficial effects as the photovoltaic cell, and the related parts between the two can be referred to each other. In order to avoid repetition, it will not be described here.

[0112] The photovoltaic cell provided by the embodiments of the present disclosure includes a laser absorption layer disposed on the side of the second transport layer 3 away from the back light surface, and a second conductive layer 6 disposed on the side of the laser absorption layer away from the back light surface. When the laser etching process is performed on the second conductive layer 6 to form an insulating groove 61, the laser absorption layer expands due to heat absorption, and the laser absorption layer pushes the edge of the second conductive layer 6 close to the insulating groove 61 outward to form a warping part 62, thereby avoiding the residue of the second conductive layer 6 at the position of the insulating groove 61 from being attached to the inside of the insulating groove 61 to form a leakage path with the first conductive layer 5, and improving the production yield of the cell. Moreover, the warping part 62 formed by the edge of the insulating groove 61 can block the damage to the second conductive layer 6 and the silicon substrate 1 in the wet cleaning process, and can further improve the production yield of the cell.

[0113] The above only describes the preferred embodiments of the present disclosure and should not be used to limit the present disclosure. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A photovoltaic cell, comprising: a silicon substrate, the silicon substrate comprising a back surface, the back surface of the silicon substrate being provided with a first region and a second region; a first transport layer provided in the first region; a second transport layer provided in the second region, the second transport layer being different from the first transport layer in a doping type; a laser absorption protective layer provided on a side of the second transport layer away from the back surface, and exposing an electrode contact region of the second transport layer; a first conductive layer provided on a side of the first transport layer away from the back surface; a second conductive layer provided on a side of the laser absorption protective layer away from the back surface, the second conductive layer covering the laser absorption protective layer and the electrode contact region of the second transport layer, a region of the second conductive layer close to the first conductive layer being provided with an insulating groove, the second conductive layer forming a warping portion warping from an inner side of the insulating groove to an outer side of the insulating groove at an edge of a slot of the insulating groove.

2. The photovoltaic cell of claim 1, wherein, further comprising: a first electrode provided in the first region and in contact with the first conductive layer; a second electrode provided in the second region and in contact with the second conductive layer corresponding to the electrode contact region, the insulating groove being located between the first electrode and the second electrode.

3. The photovoltaic cell of claim 1, wherein, the first transport layer comprising a first passivation layer and a first doped layer provided in the back surface in sequence, the first conductive layer being provided on a side of the first doped layer away from the silicon substrate; the second transport layer comprising a second passivation layer and a second doped layer provided in the back surface in sequence, the first doped layer and the second doped layer being different in the doping type, the laser absorption protective layer being provided on a side of the second doped layer away from the silicon substrate.

4. The photovoltaic cell of claim 3, wherein, the first passivation layer and the second passivation layer are both amorphous silicon; the first doped layer and the second doped layer are both doped amorphous silicon or doped microcrystalline silicon; or, the first passivation layer and the second passivation layer are both silicon oxide; the first doped layer and the second doped layer are doped polysilicon or doped microcrystalline silicon; or, the first passivation layer and the second passivation layer are respectively amorphous silicon and silicon oxide, and the first doped layer and the second doped layer are respectively doped polysilicon and doped microcrystalline silicon.

5. The photovoltaic cell of claim 1, wherein, the laser absorption protective layer comprises: an insulating layer provided on a side of the second transport layer away from the silicon substrate, and exposing the electrode contact region of the second transport layer; a laser absorption layer provided on a side of the insulating layer away from the silicon substrate, and exposing the electrode contact region of the second transport layer.

6. The photovoltaic cell of claim 5, wherein, the insulating layer is one or a stack of at least two of a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, and a silicon carbide layer.

7. The photovoltaic cell of claim 5, wherein, the laser absorption layer is one or a stack of at least two of an amorphous silicon layer, a nanocrystalline silicon layer, a microcrystalline silicon layer, and a polysilicon layer.

8. The photovoltaic cell of claim 5, wherein, the laser absorption layer comprises: a first laser absorption layer provided on a side of the insulating layer away from the silicon substrate, and exposing the electrode contact region; a second laser absorption layer provided on a side of the first laser absorption layer away from the silicon substrate, and exposing the electrode contact region.

9. The photovoltaic cell of claim 8, wherein, The first laser absorption layer is an intrinsic amorphous silicon layer, and the second laser absorption layer is a doped amorphous silicon layer.

10. The photovoltaic cell of claim 5, wherein, The insulating groove at least partially penetrates the laser absorption layer.

11. The photovoltaic cell of claim 5, wherein, The total thickness of the laser absorption layer is 5-50 nm.

12. The photovoltaic cell of claim 1, wherein, The thickness of the second conductive layer is 40-150 microns.

13. The photovoltaic cell of claim 1, wherein, The height of the warping portion is 0.2-2 microns.

14. The photovoltaic cell of claim 1, wherein, The included angle B between the warping portion and the side of the second conductive layer close to the silicon substrate is 15-150°.

15. The photovoltaic cell of claim 1, wherein, The included angle B between the warping portion and the side of the second conductive layer close to the silicon substrate is 90-150°.

16. The photovoltaic cell of claim 1, wherein, The silicon substrate further comprises a light-receiving side opposite to the back light side, and the photovoltaic cell further comprises: a front passivation layer arranged on the light-receiving side; a reflection-reducing film layer arranged on the side of the front passivation layer away from the silicon substrate.

17. A photovoltaic module comprising the photovoltaic cell according to any one of claims 1-16.

18. A photovoltaic system comprising the photovoltaic module according to claim 17.

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