A solar cell and a photovoltaic module

Abstract

The embodiment of the present application provides a solar cell and a photovoltaic module. The solar cell includes: a silicon substrate, the silicon substrate has a first surface, the first surface includes metallized areas and non-metallized areas alternately distributed along a first direction, the non-metallized areas located in the edge area of ​​the first surface are edge non-metallized areas, and the non-metallized areas located in the center area of ​​the first surface are center non-metallized areas; a dielectric layer, the dielectric layer is arranged on the surface of the metallized area; a doped conductive layer, the doped conductive layer is arranged on the side of the dielectric layer away from the silicon substrate; wherein the depth of the edge non-metallized area is less than the depth of the center non-metallized area. The embodiment of the present application can reduce the damage to the edge area of ​​the solar cell caused by the cleaning process, avoid the phenomenon of edge collapse, and improve the yield rate of the solar cell.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic processing technology, and specifically relates to a solar cell and a photovoltaic module. Background Art

[0002] With the development of science and technology, solar energy has developed rapidly as a new type of clean photovoltaic energy in recent years. Among them, solar cells are a kind of optoelectronic semiconductor sheet that can directly generate electricity using sunlight, and their performance is gradually pursuing high conversion efficiency, low attenuation performance and high mass production cost performance.

[0003] In the process of processing existing solar cells, it is usually necessary to perform laser patterning on the cell to form a non-metallized area on the cell. After the laser patterning is completed, it is usually necessary to clean the damage caused by the laser patterning.

[0004] However, in the process of cleaning the solar cell, in the process of cleaning the non-metallized area in the edge area, it is easy to cause damage to the edge of the cell, resulting in edge collapse, which greatly reduces the yield rate of the solar cell. Summary of the invention

[0005] The present application aims to provide a solar cell and a photovoltaic module to solve the problem that the edges of the cell sheets in the existing solar cells are easily damaged.

[0006] In order to solve the above technical problems, this application is implemented as follows:

[0007] In a first aspect, the present application discloses a solar cell, comprising:

[0008] A silicon substrate having a first surface, wherein the first surface includes a metallized area and a non-metallized area;

[0009] The metallization area includes doped conductive layers arranged at intervals;

[0010] The non-metallized area located at the edge of the first surface is the edge non-metallized area, and the non-metallized area located at the center of the first surface is the center non-metallized area, wherein the depth of the edge non-metallized area is less than the depth of the center non-metallized area.

[0011] Optionally, a depth of the edge non-metallized area and a depth of the central non-metallized area have a first difference, and the first difference is greater than 0 and less than or equal to 2 um.

[0012] Optionally, the depth range of the edge non-metallized area is 1-3 um; the depth range of the central non-metallized area is 2-4 um.

[0013] Optionally, the width of the edge non-metallized area along the first direction is a first width, the width of the central non-metallized area along the first direction is a second width, and the first width is less than or equal to the second width.

[0014] Optionally, the first width ranges from 300-700 um; and the second width ranges from 500-1500 um.

[0015] Optionally, the metallized area is provided with a first texture structure, and the non-metallized area is provided with a second texture structure, and a one-dimensional size of a bottom of the first texture structure is smaller than a one-dimensional size of a bottom of the second texture structure.

[0016] Optionally, a one-dimensional size of the bottom of the first texture structure is 5-9 um; and a one-dimensional size of the bottom of the second texture structure is 9-18 um.

[0017] Optionally, the depth of the first texture structure and the second texture structure is 0.05-2 um.

[0018] Optionally, the non-metallized area is provided with a pyramid-shaped velvet structure.

[0019] Optionally, the width of the central non-metallized area along the first direction is a second width, the distance between the centers of two adjacent metallized areas along the first direction is a first distance, and the ratio of the second width to the first distance is in a range of 0.2-0.7;

[0020] And / or, the distance between centers of two adjacent metallized areas along the first direction is 1-3 mm.

[0021] Optionally, the solar cell further comprises a passivation layer, and the passivation layer is arranged on a side of the doped conductive layer away from the silicon substrate;

[0022] The passivation layer comprises a first region and a second region, the first region is opposite to the central non-metallized region, the second region is opposite to the edge non-metallized region, the first region is provided with a first sub-passivation layer, and the second region is provided with a second sub-passivation layer;

[0023] Wherein, the thickness of the second sub-passivation layer is greater than the thickness of the first sub-passivation layer.

[0024] In a second aspect, the present application further discloses a photovoltaic module, wherein the photovoltaic module comprises a battery string, and the battery string comprises any one of the solar cells described above.

[0025] In the embodiment of the present application, the depth of the edge non-metallized area of ​​the solar cell is less than the depth of the central non-metallized area. In the process of cleaning the laser damage of the metallized area, since the depth of the edge non-metallized area is smaller, it is advantageous to use a smaller cleaning intensity to clean the edge non-metallized area. In this way, the damage to the edge area of ​​the solar cell caused by the cleaning process can be reduced, the phenomenon of edge collapse can be avoided, and the yield rate of the solar cell can be improved.

[0026] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0028] Figure 1 This is a schematic diagram of the structure of a solar cell described in an embodiment of the present application.

[0029] Figure numerals: 10 - silicon substrate, 101 - metallized area, 102 - non-metallized area, 1021 - edge non-metallized area, 1022 - central non-metallized area, 11 - dielectric layer, 12 - doped conductive layer, X - first direction. DETAILED DESCRIPTION

[0030] Embodiments of the present invention will be described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0031] The term "first" or "second" in the specification and claims of the present application may include one or more of the features explicitly or implicitly. In the description of the present invention, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0032] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] Reference Figure 1 , shows a schematic structural diagram of a solar cell according to an embodiment of the present application, such as Figure 1 As shown, the solar cell may specifically include: a silicon substrate 10, the silicon substrate 10 has a first surface, the first surface includes a metallized area 101 and a non-metallized area 102, the metallized area 101 includes doped conductive layers arranged at intervals, the non-metallized area 102 located in the edge area of ​​the first surface is an edge non-metallized area 1021, and the non-metallized area 102 located in the center area of ​​the first surface is a center non-metallized area 1022.

[0035] In some embodiments, the metallized area 101 includes doped conductive layers arranged at intervals, and the doped conductive layer includes an area that can be used to form an electrode, so that the electrode can contact the doped conductive layer 12 in the area. Taking into account the accuracy of the electrode manufacturing process, the metallized area 101 includes the electrode position and the doped conductive layer not covered by the electrode. The non-metallized area 102 located at the edge area of ​​the solar cell is an edge non-metallized area 1021. The edge non-metallized area 1021 means that the edge doped conductive layer and the dielectric layer are removed to play the role of edge isolation. The non-metallized area 102 outside the edge non-metallized area 1021 is a central non-metallized area 1022, which is mainly used to reduce the negative impact of parasitic absorption caused by the doped conductive layer on the battery efficiency.

[0036] In some embodiments, the depth H1 of the edge non-metallized area 1021 of the solar cell is smaller than the depth H2 of the central non-metallized area 1022. In the process of cleaning the laser damage of the metallized area 101, since the depth H1 of the edge non-metallized area 1021 is smaller, it is advantageous to use a smaller cleaning intensity to complete the cleaning of the edge non-metallized area 1021. In this way, the damage to the edge area of ​​the solar cell caused by the cleaning process can be reduced, the edge collapse phenomenon can be avoided, and the yield rate of the solar cell can be improved.

[0037] Specifically, the depth of the non-metallized area 102 may be the depth of the bottom of the non-metallized area 102 being recessed relative to the first surface. In practical applications, the depth of the non-metallized area 102 may be measured with the first surface as a reference plane.

[0038] In some embodiments, the silicon substrate 10 can be used to receive incident light and generate photogenerated carriers. In some embodiments, the material of the silicon substrate 10 may include one or more of single crystal silicon, polycrystalline silicon, amorphous silicon or microcrystalline silicon. In other embodiments, the material of the silicon substrate 10 may also be silicon carbide, organic material or multi-component compound. Multi-component compounds may include but are not limited to materials such as perovskite, gallium arsenide, cadmium telluride, copper indium selenide, etc. Exemplarily, in the present application, the silicon substrate 10 is a single crystal silicon substrate. The silicon substrate 10 has doping elements in it, and the doping element conductivity type may be N-type or P-type. The N-type element may be a group V element such as phosphorus (P), bismuth (Bi), antimony (Sb) or arsenic (As), and the P-type element may be a group III element such as boron (B), aluminum (Al), gallium (Ga) or indium (In). For example, when the silicon substrate 10 is a P-type silicon substrate, the conductivity type of the doping element inside it is P-type. For another example, when the silicon substrate 10 is an N-type silicon substrate, the conductivity type of the doped element inside it is N-type. For example, in the embodiment of the present application, the silicon substrate 10 is an N-type silicon substrate to improve the conversion efficiency of the solar cell and reduce the manufacturing cost.

[0039] The solar cell can be applied to various types of cell structures, including but not limited to tunnel oxide passivated contact cell (Tunnel Oxide Passivated Contact, TOPCon), interdigitated back contact cell (Interdigitated Back Contact, IBC), emitter and back passivated cell (Passivated Emitter Rear Cell, PERC), etc., without limitation. Taking TOPCon cell as an example, the first surface can be the backlight surface of the solar cell.

[0040] It should be noted that the first surface may also be the light-receiving surface of the solar cell, and the embodiment of the present application may not limit the specific position of the first surface on the solar cell.

[0041] In some embodiments, the first surface of the silicon substrate 10 includes a metallized area 101 and a non-metallized area 102. The metallized area 101 includes a doped conductive layer 12 distributed at intervals, and the non-metallized area 102 can reduce the risk of battery leakage, or reduce the area of ​​the doped conductive layer on the first surface of the solar cell, reduce the negative impact of parasitic absorption caused by the doped conductive layer on the battery efficiency, or reduce the impact of leakage and parasitic absorption on the solar cell.

[0042] In some embodiments, the metallization region further includes a dielectric layer 11 , and the dielectric layer 11 is disposed between the surface of the metallization region 101 and the doped conductive layer.

[0043] In some embodiments, the material of the dielectric layer 11 includes a single layer or a stacked structure made of one or more materials of dielectric materials with tunneling effect such as silicon oxide, silicon nitride, silicon oxynitride, nanocrystalline silicon, intrinsic amorphous silicon and intrinsic polycrystalline silicon. The doped conductive layer 12 includes a single layer or a stacked structure made of one or more materials of doped amorphous silicon, doped microcrystalline silicon and doped polycrystalline silicon. The polarity of the doped element in the doped conductive layer 12 is the same as that of the silicon substrate 10, and a concentration difference is formed between the doped conductive layer 12 and the silicon substrate 10, thereby forming a high-low junction, or the polarity of the doped element is opposite to that of the silicon substrate 10, and a PN junction is formed with the silicon substrate 10. The dielectric layer 11 can realize the selective transmission of carriers on the surface of the silicon substrate 10, reducing the recombination probability of holes on the surface of the silicon substrate. The doped conductive layer 12 can improve the transmission efficiency of carriers and reduce the contact resistance of the solar cell.

[0044] Optionally, the depth H1 of the edge non-metallized area 1021 and the depth H2 of the central non-metallized area 1022 have a first difference, and the first difference is greater than 0 and less than or equal to 2um. In practical applications, the first difference needs to be greater than 0 so that the depth of the edge non-metallized area 1021 is smaller, which is convenient for cleaning the edge non-metallized area 1021 and reducing damage to the edge of the battery cell. At the same time, the first difference needs to be less than or equal to 2um so that the depth H1 of the edge non-metallized area 1021 is not too small to achieve the effect of edge isolation. That is, when the first difference is greater than 0 and less than or equal to 2um, the cleaning effect and edge isolation effect of the edge non-metallized area 1021 can be taken into account.

[0045] For example, the first difference may be 0.3 um, 0.5 um, 1.0 um, 1.4 um or 2 um, etc. The embodiment of the present application does not specifically limit the value of the first difference.

[0046] In some embodiments, the depth H1 of the edge non-metallized area 1021 ranges from 1 to 3 um; the depth H2 of the center non-metallized area 1022 ranges from 2 to 5 um. In practical applications, if the depth of the non-metallized area 102 is too small, the passivation isolation effect of the non-metallized area 102 may be affected. If the depth of the non-metallized area 102 is too large, the mechanical strength of the solar cell will be affected, increasing the risk of breakage or edge cracking of the solar cell.

[0047] In some embodiments, by setting the depth of the edge non-metallized area 1021 to 1-3um and the depth of the central non-metallized area 1022 to 2-5um, the passivation isolation effect and the mechanical strength of the edge non-metallized area 1021 and the central non-metallized area 1022 can be taken into account, and at the same time, the depth H1 of the edge non-metallized area 1021 can be made smaller than the depth H2 of the central non-metallized area 1022.

[0048] For example, the depth H1 of the edge non-metallized area 1021 can be 1um, 2.5um, 3.0um, 3.4um or 4um, and the depth H2 of the central non-metallized area 1022 can be 2 um, 2.8um, 3.5um, 4.4um or 5um, etc. The embodiment of the present application does not specifically limit the depths of the edge non-metallized area 1021 and the central non-metallized area 1022.

[0049] In some embodiments, the width W1 of the edge non-metallized area 1021 along the first direction X is the first width, the width of the central non-metallized area 1022 along the first direction X is the second width W2, and the first width W1 is less than or equal to the second width W2. In practical applications, the width of the non-metallized area 102 along the first direction X needs to comprehensively consider the transmission performance and processability of the carriers. Usually, the edge non-metallized area 1021 has a metallized area on only one side, so that the path selectivity of the carriers in the edge non-metallized area 1021 from the non-metallized area 102 to the metallized area 101 is less than that of the carriers in the central non-metallized area 1022. In order to reduce the transmission path of the carriers in the edge non-metallized area 1021 and reduce the probability of their recombination, therefore, the first width W1 of the edge non-metallized area 1021 needs to be less than or equal to the second width W2 of the central non-metallized area 1022. Moreover, in the process of forming the non-metallized area 102 by laser engraving, the edge non-metallized area 1021 with a narrower width is easier to process.

[0050] Optionally, the first width W1 ranges from 100-700um; the second width W2 ranges from 500-1500um. In practical applications, when the width of the non-metallized area 102 is less than 100um, the isolation effect of the non-metallized area 102 may be poor. When the width of the non-metallized area 102 is greater than 1500um, the Rs high electrical performance may be reduced due to the large lateral transmission of the slot being too wide. That is, based on the comprehensive selection of the size of the laser spot and the lateral transmission difference of the slotted area, the first width W1 can be set to 100-700um; and the second width W2 can be set to 500-1500um.

[0051] For example, the first width W1 may be 100um, 200um, 300um, 400um, 500um, 600um or 700um, etc., and the second width W2 may be 500um, 700um, 1000um, 1300um or 1500um, etc. The embodiment of the present application does not specifically limit the first width W1 and the second width W2.

[0052] In some optional embodiments of the present application, the metallized area 101 is provided with a first texture structure, and the non-metallized area 102 is provided with a second texture structure, and the one-dimensional size of the bottom of the first texture structure is smaller than the one-dimensional size of the bottom of the second texture structure.

[0053] In some embodiments, the first texture structure of the metallized area 101 and the second texture structure of the non-metallized area 102 can both increase the surface area, which is beneficial to increase the coverage area of ​​the later film layer on the silicon substrate 10, thereby obtaining a higher passivation quality. The non-metallized area 102 is relatively more damaged during the patterning process, and the damaged area will bring more composite sites, so better passivation performance is required.

[0054] In some embodiments, the one-dimensional size of the bottom of the first texture structure on the metallized area 101 is smaller than the one-dimensional size of the bottom of the second texture structure on the non-metallized area 102, so that the ratio of the actual surface area to the plane area of ​​the non-metallized area 102 is large, that is, the specific surface area is large, which can increase the area of ​​the film layer covering the non-metallized area 102 and improve the passivation quality of the non-metallized area 102. That is, by designing texture structures of different sizes at the bottom of the metallized area 101 and the non-metallized area 102, the passivation quality of the non-metallized area 102 can be more specifically improved, so that the prepared solar cell can obtain a higher cell conversion efficiency.

[0055] It should be noted that, in one embodiment, the first texture structure and the second texture structure may be formed in the metallized area 101 and the non-metallized area 102 by laser or chemical etching. The one-dimensional size of the bottom of the first texture structure and the second texture structure may specifically be the distance between the farthest two points of the orthographic projection of the first texture structure or the second texture structure on the first surface, which is not limited here. In some examples, when measuring the one-dimensional size, the film surface calibration may be directly measured by a testing instrument (optical microscope, atomic force microscope, scanning electron microscope, transmission electron microscope, etc.).

[0056] For example, the bottom of the first texture structure and the second texture structure is a polygonal plane. Specifically, the bottom of the first texture structure and the second texture structure can be at least one of a rhombus, a square, a trapezoid, a nearly rhombus, a nearly square, and a nearly trapezoid. Of course, the bottom of the first texture structure and the second texture structure can also be a polygon of other shapes, which is not limited here.

[0057] Optionally, the one-dimensional size of the bottom of the first texture structure is 5-9 um, and further, the one-dimensional size of the bottom of the first texture structure can be 5 um, 6 um, 7 um, 7.5 um, 8 um or 9 um. Of course, the one-dimensional size of the bottom of the first texture structure can also be other values ​​within the above range, which can be set according to actual needs and is not limited here.

[0058] Optionally, the one-dimensional size of the bottom of the second texture structure is 9-18um, and further, the one-dimensional size of the bottom of the second texture structure can be 9 um, 11 um, 14 um, 15 um, 17um or 18um. Of course, the one-dimensional size of the bottom of the second texture structure can also be other values ​​within the above range, which can be set according to actual needs and is not limited here.

[0059] Specifically, if the one-dimensional size of the bottom of the first texture structure and the second texture structure is too small, the unevenness of the surface of the metallized area 101 and the non-metallized area 102 will increase, which is not conducive to the subsequent coating quality of the non-metallized area 102; if the one-dimensional size of the bottom of the first texture structure and the second texture structure is too large, the difficulty of preparing the first texture structure and the second texture structure will increase, and the one-dimensional size is too large, which will lead to a smaller specific surface area of ​​the non-metallized area 102, and cannot achieve the purpose of increasing the subsequent coating area, which is not conducive to the passivation of the non-metallized area 102. In practical applications, when the one-dimensional size of the bottom of the first texture structure is 5-9um and the one-dimensional size of the bottom of the second texture structure is 9-18um, the difficulty of preparing the non-metallized area 102 can be reduced, the preparation efficiency can be improved, and the non-metallized area 102 can obtain a higher passivation quality, thereby improving the conversion efficiency of the solar cell.

[0060] Optionally, the depth of the first texture structure and the second texture structure is 0.05-2 um. For example, the first texture structure and the second texture structure may be a recessed structure, and the recessed depth of the recessed structure may be 0.05μm, 0.1μm, 0.15μm, 0.2μm, etc. Of course, the recessed depth of the recessed structure may also be other values ​​within the above range, which may be set according to actual needs and is not limited here. In this embodiment, when the recessed depth of the recessed structure is 0.05μm to 2μm, the unevenness of the surface of the non-metallized area 102 can be controlled within the desired range, which is beneficial to improving the passivation effect of the non-metallized area 102.

[0061] In some embodiments, the non-metallized area 102 is provided with a pyramid-shaped suede structure. In practical applications, the pyramid-shaped suede structure can reduce reflection, increase light absorption, and improve photoelectric conversion efficiency.

[0062] Specifically, the texturing process can increase the roughness of the surface of the silicon substrate 10 by forming a velvet structure on the surface of the non-metallized area 102, thereby reducing light reflection and increasing light absorption. This velvet structure can change the incident angle and propagation path of light, form a light trap, further increase the density of photogenerated carriers, and ultimately improve the photoelectric conversion rate of the solar cell.

[0063] In some embodiments, the width of the central non-metallized area 1022 along the first direction X is the second width W2, the distance between the centers of two adjacent metallized areas 101 along the first direction X is the first distance W3, and the ratio of the second width W2 to the first distance W3 is in the range of 0.2-0.7. In a specific application, when the ratio of the second width W2 to the first distance W3 is greater than 0.7, the lateral transmission distance of the photogenerated carriers is too large, which may cause the FF loss problem. When the ratio of the second width W2 to the first distance W3 is less than 0.2, the subsequent coverage area of ​​the doped conductive layer 12 increases, which increases the parasitic absorption of the doped conductive layer 12 and reduces the battery efficiency.

[0064] For example, the ratio of the second width W2 to the first distance W3 may be 0.2, 0.35, 0.45, 0.5, 0.6 or 0.7, etc. The embodiment of the present application does not specifically limit the ratio of the second width W2 to the first distance W3.

[0065] Optionally, the second width W2 of the central non-metallized area 1022 along the first direction X is 0.5 mm-1.5 mm, so that the lateral transmission distance of the photogenerated carriers is more appropriate and convenient for processing. For example, the second width W2 of the central non-metallized area 1022 along the first direction X can be 0.5 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.3 mm or 1.5 mm, etc. The embodiment of the present application does not specifically limit the second width W2 of the central non-metallized area 1022 along the first direction X.

[0066] Optionally, the distance between the centers of two adjacent metallized areas 101 along the first direction X is 1-3 mm, so as to control the width of the metallized area 101 along the first direction X within a suitable range, so as to facilitate the arrangement of the dielectric layer 11 and the doped conductive layer 12 on the metallized area 101. For example, the distance between the centers of two adjacent metallized areas 101 along the first direction X may be 1 mm, 1.2 mm, 1.5 mm, 2.2 mm, 2.5 mm or 3 mm, etc. The embodiment of the present application does not specifically limit the distance between the centers of two adjacent metallized areas 101 along the first direction X.

[0067] In some embodiments, the solar cell also includes a passivation layer, which is arranged on the side of the doped conductive layer 12 away from the silicon substrate 10; the passivation layer may include a first region and a second region, the first region is opposite to the central non-metallized region 1022, the second region is opposite to the edge non-metallized region 1021, the first region is provided with a first sub-passivation layer, and the second region is provided with a second sub-passivation layer; wherein the thickness of the second sub-passivation layer is greater than the thickness of the first sub-passivation layer.

[0068] In a specific application, since there are more defects on the side of the edge non-metallized area 1021 close to the edge of the cell, a better passivation effect can be obtained by setting the second sub-passivation layer on the edge non-metallized area 1021 to be thicker.

[0069] The following is a processing flow of a solar cell according to an embodiment of the present application:

[0070] First, a dielectric layer 11 and a doped conductive layer 12 may be deposited on the first surface of the silicon substrate 10. The dielectric layer 11 may be a tunneling oxide layer, and the doped conductive layer 12 may be a doped polysilicon layer.

[0071] Then, a laser patterning process is performed on the prepared doped conductive layer 12 to modify the doped conductive layer 12 to form an edge non-metallized area 1021 and a central non-metallized area 1022. The edge non-doped area and the central non-doped area can be prepared by a process laser process or by different laser processes, for example, the edge and central doped conductive layers 12 are modified by lasers with different laser powers.

[0072] Finally, selective etching is performed, using a chain machine to remove the dielectric layer 11 plated around the front and edges of the cell, and using a slot machine etching solution to remove the dielectric layer 11, doped conductive layer 12, and part of the silicon substrate 10 in the non-metallized area 102 to form a non-metallized area 102. It should be noted that the order of selective etching is adjustable, for example, a chain machine can be used to first remove the dielectric layer 11 plated around the front and edges of the cell, and then a slot machine etching solution can be used to remove the dielectric layer 11, doped conductive layer 12, and part of the silicon substrate 10 in the non-metallized area 102 to form a non-metallized area 102; or a slot machine etching solution can be used to first remove the dielectric layer 11, doped conductive layer 12, and part of the silicon substrate 10 in the non-metallized area 102 to form a non-metallized area 102, and then a chain machine can be used to remove the dielectric layer 11 plated around the front and edges of the cell, and there is no special limitation here.

[0073] In summary, the solar cell described in the embodiment of the present application has at least the following advantages:

[0074] In the embodiment of the present application, the depth of the edge non-metallized area of ​​the solar cell is less than the depth of the central non-metallized area. In the process of cleaning the laser patterned non-metallized area, since the depth of the edge non-metallized area is smaller, it is advantageous to use a smaller cleaning intensity to clean the edge non-metallized area. In this way, the damage to the edge area of ​​the solar cell caused by the cleaning process can be reduced, the edge collapse phenomenon can be avoided, and the yield rate of the solar cell can be improved.

[0075] The embodiment of the present application further provides a photovoltaic assembly, wherein the photovoltaic assembly includes a battery string, and the battery string may specifically include the solar cell described in any of the above embodiments.

[0076] It should be noted that in the photovoltaic assembly described in the embodiment of the present application, the structure of the solar cell is the same as the structure of the solar cell described in any of the above embodiments, and its beneficial effects are also similar, which will not be elaborated here.

[0077] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0078] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A solar cell, characterized in that: The solar cell comprises: A silicon substrate having a first surface, wherein the first surface includes a metallized area and a non-metallized area; The metallization area includes doped conductive layers arranged at intervals; The non-metallized area located at the edge area of ​​the first surface is an edge non-metallized area, and the non-metallized area located at the center area of ​​the first surface is a center non-metallized area, wherein the depth of the edge non-metallized area is less than the depth of the center non-metallized area.

2. The solar cell according to claim 1, characterized in that A depth of the edge non-metallized area and a depth of the central non-metallized area have a first difference, and the first difference is greater than 0 and less than or equal to 2 um.

3. The solar cell according to claim 1, characterized in that The depth of the edge non-metallized area ranges from 1 to 3 um; the depth of the central non-metallized area ranges from 2 to 5 um.

4. The solar cell according to claim 1, characterized in that The width of the edge non-metallized area along the first direction is a first width, the width of the central non-metallized area along the first direction is a second width, and the first width is less than or equal to the second width.

5. The solar cell according to claim 4, characterized in that: The first width ranges from 100 to 700 um; the second width ranges from 500 to 1500 um.

6. The solar cell according to claim 1, characterized in that The metallized area is provided with a first texture structure, and the non-metallized area is provided with a second texture structure. The one-dimensional size of the bottom of the first texture structure is smaller than the one-dimensional size of the bottom of the second texture structure.

7. The solar cell according to claim 6, characterized in that: The one-dimensional size of the bottom of the first texture structure is 5-9 um; the one-dimensional size of the bottom of the second texture structure is 9-18 um.

8. The solar cell according to claim 6, characterized in that: The depth of the first texture structure and the second texture structure is 0.05-2 um.

9. The solar cell according to claim 1, characterized in that: The non-metallized area is provided with a pyramid-shaped velvet structure.

10. The solar cell according to claim 1, characterized in that The width of the central non-metallized area along the first direction is a second width, the distance between the centers of two adjacent metallized areas along the first direction is a first distance, and the ratio of the second width to the first distance is in a range of 0.2-0.7; And / or, the distance between centers of two adjacent metallized areas along the first direction is 1-3 mm.

11. The solar cell according to claim 1, characterized in that: The solar cell further comprises a passivation layer, wherein the passivation layer is arranged on a side of the metallized conductive layer away from the silicon substrate; The passivation layer comprises a first region and a second region, the first region is opposite to the central non-metallized region, the second region is opposite to the edge non-metallized region, the first region is provided with a first sub-passivation layer, and the second region is provided with a second sub-passivation layer; Wherein, the thickness of the second sub-passivation layer is greater than the thickness of the first sub-passivation layer.

12. A photovoltaic module, characterized in that: The photovoltaic module comprises a battery string, and the battery string comprises the solar cell according to any one of claims 1 to 11.

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