Solar cell, photovoltaic module and photovoltaic system

Abstract

The utility model relates to the technical field of solar cells. The utility model relates to a solar cell, a photovoltaic module and a photovoltaic system. The solar cell comprises a silicon substrate, the silicon substrate comprises a plurality of oxygen precipitation areas which are arranged along a first direction and extend along a second direction, the interstitial oxygen content of the oxygen precipitation areas is higher than the content of other areas of the silicon substrate, and the first direction intersects with the second direction; the middle structure layer is located on the first surface of the silicon substrate; the first conductive layer is located on the surface of the middle structure layer away from the silicon substrate; the first electrode is arranged in contact with the first conductive layer and comprises a plurality of first grid lines, and the projection of at least one first grid line towards the silicon substrate is correspondingly at least partially overlapped with the oxygen precipitation area, so that annular or spiral black rings distributed along the radial direction in the related technology can be avoided, the area of the oxygen precipitation area can be minimized, and the oxygen precipitation efficiency can be improved. And the quality inspection passing rate of the crystalline silicon solar cell can be improved.

Description

Technical Field

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

[0002] In recent years, with the rapid development of photovoltaic technology, the conversion efficiency of crystalline silicon solar cells has increased year by year. Currently, TOPCon, HJT and other solar cells stand out with many advantages such as high efficiency and high maturity of industrial process.

[0003] In the related art, the silicon substrate of a crystalline silicon solar cell generally has an annular or spiral oxygen precipitation area distributed along the radial direction. During the detection stage of the crystalline silicon solar cell, for example, under photoluminescence detection PL or electroluminescence detection EL, the oxygen precipitation area will appear as a "black ring", as shown in Figure 1, which will seriously affect the quality inspection pass rate of the crystalline silicon solar cell. Utility Model Content

[0004] Based on this, it is necessary to provide a solar cell, a photovoltaic module and a photovoltaic system that can improve the detection yield.

[0005] A first aspect of an embodiment of the present application provides a solar cell, comprising:

[0006] A silicon substrate, the silicon substrate comprising a plurality of oxygen precipitation regions arranged along a first direction and extending along a second direction, wherein interstitial oxygen content of the oxygen precipitation regions is higher than that of other regions of the silicon substrate, and the first direction intersects the second direction;

[0007] An intermediate structure layer, located on the first surface of the silicon substrate;

[0008] A first conductive layer, located on a surface of the intermediate structure layer away from the silicon substrate;

[0009] A first electrode is arranged in contact with the first conductive layer, wherein the first electrode includes a plurality of first gate lines, and a projection of at least one of the first gate lines toward the silicon substrate at least partially overlaps with the oxygen precipitation region.

[0010] In one of the embodiments, the silicon substrate is formed by cutting a silicon rod along an extension direction of the silicon rod, wherein the second direction is the same as the extension direction of the silicon rod.

[0011] In one embodiment, projections of the plurality of first gate lines toward the silicon substrate fall into the plurality of oxygen precipitation regions in a one-to-one correspondence.

[0012] In one of the embodiments, along the second direction, the range of interstitial oxygen content in the oxygen precipitation region does not exceed 2 ppma.

[0013] In one embodiment, the intermediate structure layer includes: a tunneling oxide layer located on the first surface of the silicon substrate;

[0014] The first conductive layer comprises: a first doped conductive layer, located on a surface of the tunnel oxide layer away from the silicon substrate; wherein,

[0015] The solar cell further comprises:

[0016] The first passivation layer is located on the surface of the doped conductive layer away from the tunneling oxide layer; wherein the first end of the first electrode passes through the first passivation layer and contacts the doped conductive layer, and the second end of the first electrode is exposed outside the first passivation layer.

[0017] In one embodiment, the solar cell further comprises:

[0018] A second doped conductive layer is located on a second surface of the silicon substrate, the first surface and the second surface are arranged opposite to each other;

[0019] A second passivation layer is located on a surface of the second doped conductive layer away from the silicon substrate;

[0020] A second electrode is arranged in contact with the second doped conductive layer, wherein the second electrode includes a plurality of second gate lines, and a projection of at least one of the second gate lines toward the silicon substrate at least partially overlaps with the oxygen precipitation region.

[0021] In one embodiment, the intermediate structural layer comprises:

[0022] A first intrinsic layer, located on a first surface of the silicon substrate;

[0023] A first doping layer is located on a surface of the first intrinsic layer away from the silicon substrate;

[0024] The first conductive layer comprises:

[0025] The first transparent conductive layer is located on a surface of the first doped layer away from the first intrinsic layer, and the first electrode is disposed in contact with the first transparent conductive layer.

[0026] In one embodiment, the solar cell further comprises:

[0027] The solar cell further comprises:

[0028] A second intrinsic layer is located on a second surface of the silicon substrate, wherein the first surface and the second surface are arranged opposite to each other;

[0029] a second doping layer, located on a surface of the second intrinsic layer away from the silicon substrate;

[0030] A second transparent conductive layer is located on a surface of the second doped layer away from the second intrinsic layer; wherein the first doped layer and the second doped layer have different conductivity types;

[0031] The third electrode is arranged in contact with the second transparent conductive layer, wherein the third electrode comprises a plurality of third gate lines, and a projection of at least one of the third gate lines toward the silicon substrate at least partially overlaps with the oxygen precipitation region.

[0032] A second aspect of an embodiment of the present application provides a photovoltaic assembly, comprising at least one battery string, wherein the battery string comprises at least two of the above-mentioned solar cells.

[0033] A third aspect of an embodiment of the present application provides a photovoltaic system, comprising the above-mentioned photovoltaic component.

[0034] The above-mentioned solar cell, photovoltaic module and photovoltaic system include a silicon substrate, an intermediate structure layer, a first conductive layer and a first electrode, wherein the intermediate structure layer and the first conductive layer are sequentially stacked on the silicon substrate, wherein the silicon substrate includes a plurality of oxygen precipitation regions spaced apart along a first direction and extending along a second direction. Since the oxygen precipitation regions of the silicon substrate are spaced apart along the first direction, there will be no annular or spiral "black rings" distributed radially in the related art. Furthermore, the first electrode includes a plurality of first grid lines, and the projection of at least one first grid line toward the silicon substrate corresponds to at least partial overlap with the oxygen precipitation region. Since the first grid line is black under PL or EL detection, when the projection of the first grid line toward the silicon substrate corresponds to at least partial overlap with the oxygen precipitation region, the area of ​​the oxygen precipitation region can be minimized, thereby improving the quality inspection pass rate of the crystalline silicon solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] FIG1 is a schematic diagram showing a “black ring” under photoluminescence detection or electroluminescence detection in the related art;

[0036] FIG2 is a schematic diagram of a cross-sectional structure of a solar cell provided in an embodiment of the present application;

[0037] FIG3 is a schematic diagram of the structure of a silicon substrate provided in an embodiment of the present application;

[0038] FIG4 is a schematic diagram of the cutting direction of a silicon rod provided in an embodiment of the present application;

[0039] FIG5 is a schematic diagram of a cross-sectional structure of a TOPCon battery provided in one embodiment of the present application;

[0040] FIG6 is a schematic cross-sectional structure diagram of a TOPCon battery provided in another embodiment of the present application;

[0041] FIG7 is a schematic diagram of a cross-sectional structure of a HJT battery in an embodiment of the present application;

[0042] FIG8 is a schematic cross-sectional view of a HJT battery in another embodiment of the present application;

[0043] FIG. 9 is a schematic diagram of a photovoltaic module provided in an embodiment of the present application.

[0044] Description of Figure Numbers:

[0045] 10-silicon substrate; 11-silicon rod; 101-oxygen precipitation area; 102-other areas;

[0046] 20-intermediate structural layer; 201-tunneling oxide layer; 202-first intrinsic layer; 203-first doping layer;

[0047] 30-first conductive layer; 301-first doped conductive layer; 302-first transparent conductive layer;

[0048] 40-first electrode; 401-projection of the first gate line toward the silicon substrate; 60-second electrode; 80-third electrode;

[0049] 501 - first passivation layer; 502 - second doped conductive layer; 503 - second passivation layer;

[0050] 701 - second intrinsic layer; 702 - second doped layer; 703 - second transparent conductive layer;

[0051] 100-solar energy; battery 200-photovoltaic module; 210-battery string. DETAILED DESCRIPTION

[0052] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0053] In the description of the present invention, it should 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" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and 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 a limitation on the present invention.

[0054] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0055] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0057] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0058] The solar cell of the embodiment of the present application is described below in conjunction with the accompanying drawings. FIG2 is a schematic diagram of the structure of the solar cell provided in the embodiment of the present application. The X direction is the first direction in the plane parallel to the silicon substrate shown in FIG2, the Y direction can be the second direction in the plane parallel to the silicon substrate, and the Z direction is the direction of the built-in electric field of the PN junction formed in the solar cell shown in FIG2, that is, the longitudinal direction. Referring to FIG2, the embodiment of the present application provides a solar cell, including a silicon substrate 10, an intermediate structure layer 20, a first conductive layer 30 and a first electrode 40.

[0059] The silicon substrate 10 includes, but is not limited to, a doped semiconductor substrate made of silicon or germanium, or a doped compound semiconductor substrate made of silicon carbide, silicon germanium, gallium arsenide, indium phosphide, zinc oxide, or gallium oxide. For example, in the embodiment of the present application, the material of the silicon substrate 10 may be a doped single crystal silicon material. Furthermore, the doping element type of the silicon substrate 10 may be N-type, and the N-type element may be, for example, any one of phosphorus, arsenic, or antimony; the doping element type of the silicon substrate 10 may also be P-type, and the P-type element may be, for example, boron and gallium.

[0060] The silicon substrate 10 includes a first surface and a second surface arranged opposite to each other, wherein one of the first surface and the second surface can be a surface of the solar cell facing the sunlight (light-facing surface or light-receiving surface). The silicon substrate 10 is used to receive incident light and generate photogenerated carriers.

[0061] FIG3 is a schematic diagram of the structure of a silicon substrate. Referring to FIG3 , a silicon substrate 10 includes a plurality of oxygen precipitation regions 101 arranged along a first direction and extending along a second direction. The first direction is the X direction in FIG3 , and the second direction is the Y direction in FIG3 . The interstitial oxygen content of the oxygen precipitation region 101 is higher than that of other regions 102 of the silicon substrate 10, and the first direction intersects with the second direction. Other regions 102 can be understood as regions other than the oxygen precipitation region 101. Multiple oxygen precipitation regions 101 are arranged in parallel and spaced apart, and extend along the second direction. Different from the related art, the oxygen precipitation regions 101 of the silicon substrate 10 in the present application are not annular or spirally distributed along the radial direction, but are arranged along the first direction and extend along the second direction. The oxygen precipitation regions 101 in the embodiment of the present application are arranged in parallel with each other, and the "black ring" phenomenon in the related art will not occur.

[0062] The intermediate structure layer 20 is located on the first surface of the silicon substrate 10. The cell type of the solar cell is different, and the corresponding intermediate structure layer 20 is also different. The solar cell can be a TOPCon cell (Tunnel Oxide Passivated Contact) or a HJT cell (Heterojunction with intrinsic Thin layer) solar cell. Exemplarily, if the solar cell is a TOPCon cell, the intermediate structure layer 20 can be a tunneling oxide layer; if the solar cell is a HJT cell, the intermediate structure can include an intrinsic amorphous silicon layer, a doped conductive layer, etc. In the embodiment of the present application, the cell type of the solar cell is not further limited, nor is it limited to the above examples. The specific film layer of the intermediate structure layer 20 can be designed based on the specific type of the solar cell.

[0063] The first conductive layer 30 is located on the surface of the intermediate structure layer 20 away from the silicon substrate 10. The cell type of the solar cell is different, and the corresponding first conductive layer 30 is also different. For example, if the solar cell is a TOPCon cell, the first conductive layer 30 may be a doped conductive layer; if the solar cell is a HJT cell, the first conductive layer 30 may include a transparent conductive layer, etc. In the embodiment of the present application, the cell type of the solar cell is not further limited, nor is it limited to the above examples. The specific film layer of the first conductive layer 30 can be designed based on the specific type of the solar cell.

[0064] The first electrode 40 is arranged in contact with the first conductive layer 30, wherein the first electrode 40 includes a plurality of first grid lines (not shown in the figure), and a plurality of first fine grids are arranged in parallel and spaced apart. Please continue to refer to FIG. 3, the projection 401 of at least one first grid line toward the silicon substrate 10 overlaps at least partially with the oxygen precipitation region 101. The first electrode 40 is a metal electrode. The first grid line can be understood as a fine grid of the metal electrode, which is arranged in contact with the first conductive layer 30 and can collect current from the inside of the solar cell. Optionally, the first electrode 40 may also include a plurality of main grids (not shown in the figure), which are arranged in parallel and vertically staggered with the fine grids to form a mesh structure. The main grid can collect current from the fine grid. Optionally, the main grid can be connected to an external device (for example, a welding strip) to output the current of the solar cell. In the embodiment of the present application, the material of the first electrode 40 includes but is not limited to one or more of aluminum Al, titanium Ti, nickel Ni, cobalt Co, silver Ag, copper Cu and tin Sn. The formation method of the first electrode 40 may include one of screen printing, laser transfer and electroplating.

[0065] Optionally, the projections of the plurality of first gate lines toward the silicon substrate 10 respectively correspond to the partial overlaps of the plurality of oxygen precipitation regions 101. Exemplarily, the projections of the N first gate lines toward the silicon substrate 10 respectively correspond to the partial overlaps of the N oxygen precipitation regions 101; wherein N is a positive integer greater than or equal to 2. Generally speaking, the line width of the first gate line is less than the width of the oxygen precipitation region 101 in the first direction. It can be understood that the projections of the plurality of first gate lines toward the silicon substrate 10 respectively correspond to and fall into the plurality of oxygen precipitation regions 101.

[0066] In an embodiment of the present application, a solar cell includes a silicon substrate, an intermediate structure layer, a first conductive layer and a first electrode; the intermediate structure layer and the first conductive layer are sequentially stacked on the silicon substrate, wherein the silicon substrate includes a plurality of oxygen precipitation regions spaced apart along a first direction and extending along a second direction. Since the oxygen precipitation regions of the silicon substrate are spaced apart along the first direction, an annular or spiral "black ring" distributed radially in the related art will not appear. Furthermore, the first electrode includes a plurality of first gate lines, and the projection of at least one first gate line toward the silicon substrate corresponds to at least partial overlap with the oxygen precipitation region. Since the first gate line appears black under PL or EL detection, when the projection of the first gate line toward the silicon substrate corresponds to at least partial overlap with the oxygen precipitation region, the area of ​​the oxygen precipitation region can be minimized, thereby improving the quality inspection pass rate of the crystalline silicon solar cell.

[0067] In one embodiment, along the second direction, the range of the interstitial oxygen content of the oxygen precipitation region 101 does not exceed 2 ppma. That is, in the extension direction of the oxygen precipitation region 101, the range of the interstitial oxygen content does not exceed 2 ppma. The range can be understood as the super value between the maximum and minimum values ​​of the interstitial oxygen content. Exemplarily, in the extension direction of the oxygen precipitation region 101, the range of the interstitial oxygen content based on successive tests at multiple points is 1.27 ppma.

[0068] In an embodiment of the present application, the range of the interstitial oxygen content in the oxygen precipitation area does not exceed 2 ppma, which can ensure that the range of the interstitial oxygen content in the oxygen precipitation area is not too large. In this way, the interstitial oxygen content in the oxygen precipitation area is more uniform, which can further improve the quality pass rate of crystalline silicon solar cells under EL or PL.

[0069] FIG4 is a schematic diagram of the cutting direction of the silicon rod. Referring to FIG4, in the embodiment of the present application, the silicon substrate 10 can be cut from the silicon rod 11 along the extension direction of the silicon rod 11 (i.e., the second direction), wherein the second direction is the same as the extension direction of the silicon rod. The silicon substrate 10 is obtained by cutting the silicon rod 11 along the extension direction of the silicon rod 11 (i.e., the second direction). <100> The silicon rod 11 growing in the crystal direction. The "black ring" in the related art generally comes from the annular or spiral oxygen precipitation generated in the radial direction during the process. In the embodiment of the present application, the silicon substrate 10 is cut longitudinally, that is, the silicon rod 11 is cut along the extension direction (or growth direction) of the silicon rod 11, and its oxygen precipitation area 101 will not appear in a ring or spiral shape in the silicon substrate 10 of the embodiment of the present application, but will be distributed in parallel; that is, multiple oxygen precipitation areas 101 are arranged in parallel, and they extend along the extension direction of the silicon rod 11.

[0070] FIG5 is a schematic diagram of the cross-sectional structure of a TOPCon cell in an embodiment. Referring to FIG5, in the embodiment of the present application, for the sake of convenience, the solar cell is taken as an example of a TOPCon cell. Among them, the solar cell includes a silicon substrate 10, an intermediate structure layer 20, a first conductive layer 30, a first passivation layer 501 and a first electrode 40. Among them, the silicon substrate 10 and the first electrode 40 can refer to the above description, and will not be repeated here. In the TOPCon cell, the intermediate structure layer 20 may include a tunneling oxide layer 201, and the first conductive layer 30 may include a first doped conductive layer 301.

[0071] Among them, the tunneling oxide layer 201 is located on the first surface of the silicon substrate 10, so as to combine with the dangling bonds of the first surface to inhibit the recombination of carriers on the surface of the solar cell, thereby achieving the effects of interface passivation and tunneling, and is used to isolate the positive electrode (or negative electrode) of the solar cell from contacting the silicon substrate 10, reducing contact recombination losses, and at the same time, the carriers (electrons or holes) can tunnel through the tunneling oxide layer 201, without affecting the transmission of current in the solar cell, thereby improving the photoelectric conversion efficiency of the solar cell. Optionally, the material of the tunneling oxide layer 201 can be a dielectric material, such as at least one of silicon oxide, magnesium fluoride, silicon oxide, amorphous silicon, polycrystalline silicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide or titanium oxide. The formation method of the tunneling oxide layer 201 includes thermal growth, wet chemistry, PECVD (Plasma Enhanced Chemical Vapor Deposition), and excimer source dry oxygen, which are common means for thin film production in the art, and the present utility model does not limit its preparation method.

[0072] The tunnel oxide layer 201, the first doped conductive layer 301, and the first passivation layer 501 are stacked in sequence from the surface of the silicon substrate 10 to the direction away from the substrate in the longitudinal direction Z. The first doped conductive layer 301 is located on the surface of the tunnel oxide layer 201 away from the silicon substrate 10. The material of the first doped conductive layer 301 includes one or more of doped polycrystalline silicon, doped nanocrystalline silicon, doped microcrystalline silicon, and doped amorphous silicon.

[0073] The first passivation layer 501 is located on the surface of the doped conductive layer away from the tunnel oxide layer 201, and plays a passivation role to improve the open circuit voltage Voc and short circuit current Isc of the solar cell. When the tunnel oxide layer 201 is located on the light-receiving surface of the silicon substrate 10, the first passivation layer 501 also plays a role in light reflection, improves the absorption of sunlight, and thus improves the short circuit current Isc of the solar cell. Among them, the first end of the first electrode 40 passes through the first passivation layer 501 and contacts the first doped conductive layer 301, and the second end of the first electrode 40 is exposed to the first passivation layer 501, thereby realizing the electrical connection between the first electrode 40 and the first doped conductive layer 301.

[0074] For example, the first passivation layer 501 may be a single-layer structure or a multi-layer structure, and the material of the first passivation layer 501 includes but is not limited to at least one of aluminum oxide, silicon oxide, silicon nitride or silicon oxynitride. In addition, the first passivation layer 501 may be formed by chemical deposition.

[0075] Optionally, at least one of the first surface and the second surface of the silicon substrate 10 of the solar cell is a velvet structure (not shown in the figure), and the tunneling oxide layer 201 is arranged on the first surface to cover the velvet structure. Since the first doped conductive layer 301 is arranged on the velvet structure, the first doped conductive layer 301 at this position helps to reduce the recombination at the interface where the first surface is located, thereby achieving the interface passivation effect of the surface. In addition, the velvet structure arranged on the first surface increases the light absorption area of ​​the solar cell, increases the photocurrent of the solar cell, and helps to improve the efficiency of the solar cell.

[0076] FIG6 is a schematic diagram of a cross-sectional structure of a TOPCon cell in another embodiment. Referring to FIG6 , optionally, the solar cell is based on the aforementioned TOPCon cell, and the TOPCon cell further includes: a second doped conductive layer 502 , a second passivation layer 503 and a second electrode 60 .

[0077] Among them, the second doped conductive layer 502 is located on the second surface of the silicon substrate 10. The second doped conductive layer 502 and the silicon substrate 10 have different conductivity types, so as to form a PN junction with the silicon substrate 10 to separate the photogenerated carriers into electrons and holes. If the silicon substrate 10 is doped with N-type elements, the second doped conductive layer 502 is doped with P-type elements. If the silicon substrate 10 is doped with P-type elements, the second doped conductive layer 502 is doped with N-type elements. In the embodiment of the present application, the silicon substrate 10 is an N-type substrate as an example for explanation. At this time, the second doped conductive layer 502 can be P-type doped, for example, it can be a conductive layer doped with boron.

[0078] The second passivation layer 503 is located on the surface of the second doped conductive layer 502 away from the silicon substrate 10; the second electrode 60 is arranged in contact with the second doped conductive layer 502. That is, the second electrode 60 can pass through the second passivation layer 503 and contact the second doped conductive layer 502. The second passivation layer 503 can passivate the second doped conductive layer 502 in contact with it to increase the open circuit voltage Voc and short circuit current Isc of the solar cell. When the second doped conductive layer 502 is located on the light-receiving surface of the silicon substrate 10, the second passivation layer 503 also plays a role in light reflection, improves the absorption of sunlight, and thus increases the short circuit current Isc of the solar cell. Exemplarily, the second passivation layer 503 can adopt a single-layer structure or a multi-layer structure, and the material of the second passivation layer 503 includes but is not limited to one or more of aluminum oxide, silicon nitride and silicon oxide. Further, the structure of the second passivation layer 503 and the first passivation layer 501 can be the same.

[0079] The second electrode 60 includes a plurality of second gate lines (not shown in the figure), and the projection of at least one second gate line toward the silicon substrate 10 at least partially overlaps with the oxygen precipitation region 101. Optionally, the number of the second electrode 60 may be one or two. Further, the projection of the first electrode 40 toward the silicon substrate 10 overlaps with the projection of the second electrode 60 toward the silicon substrate 10.

[0080] Optionally, the projections of the plurality of second gate lines toward the silicon substrate 10 respectively correspond to partial overlaps with the plurality of oxygen precipitation regions 101. Exemplarily, the projections of the M second gate lines toward the silicon substrate 10 respectively correspond to partial overlaps with the M oxygen precipitation regions 101; wherein M is a positive integer greater than or equal to 2. Generally speaking, the line width of the second gate line is less than the width of the oxygen precipitation region 101 in the first direction. It can be understood that the projections of the plurality of second gate lines toward the silicon substrate 10 respectively correspond to and fall into the plurality of oxygen precipitation regions 101.

[0081] In an embodiment of the present application, a TOPCon cell includes a silicon substrate, a tunneling oxide layer, a first doped conductive layer, a first passivation layer, a second doped conductive layer, a second passivation layer, a first electrode, and a second electrode. Since the oxygen precipitation regions of the silicon substrate are arranged at intervals along the first direction, the annular or spiral "black ring" distributed radially in the related art will not appear. Further, the first electrode includes a plurality of first gate lines, and the projection of at least one first gate line toward the silicon substrate corresponds to at least partially overlap with the oxygen precipitation region. The second electrode includes a plurality of second gate lines, and the projection of at least one second gate line toward the silicon substrate corresponds to at least partially overlap with the oxygen precipitation region. Since the first gate line and the second gate line are black under PL or EL detection, when the projection of the first gate line and the second gate line toward the silicon substrate 10 corresponds to at least partially overlap with the oxygen precipitation region, the area of ​​the oxygen precipitation region can be minimized, thereby improving the quality inspection pass rate of the TOPCon cell.

[0082] FIG7 is a cross-sectional schematic diagram of an HJT cell in one embodiment. Referring to FIG7, for the sake of convenience, the solar cell is an HJT cell as an example for explanation. The solar cell includes a silicon substrate 10, an intermediate structure layer 20, a first conductive layer 30 and a first electrode 40. Among them, the silicon substrate 10 and the first electrode 40 can refer to the above description, and no further description is given here. In the HJT cell, the intermediate structure layer 20 may include a first intrinsic layer 202 and a first doped layer 203. Among them, the first intrinsic layer 202 is located on the first surface of the silicon substrate 10, and the first intrinsic layer 202 may be an intrinsic amorphous silicon layer, which may be a passivated silicon substrate, and the intrinsic amorphous silicon layer may be deposited by a radio frequency plasma enhanced chemical vapor deposition process. The first doped layer 203 is located on the surface of the first intrinsic layer 202 away from the silicon substrate 10. Among them, the first doped layer 203 may be a doped amorphous silicon layer or a nanocrystalline silicon layer or a microcrystalline silicon layer. Exemplarily, the silicon substrate 10 may be an N-type silicon substrate, the doping element of the first doping layer 203 thereof may be an N-type element, and the first doping layer 203 may be an N-type amorphous silicon layer to form a nn+ high-low junction to promote electron flow.

[0083] The first conductive layer 30 includes: a first transparent conductive layer 302, which is located on the surface of the first doped layer 203 away from the first intrinsic layer 202, and is used to collect and transmit current. The material of the first transparent conductive layer 302 includes but is not limited to at least one of indium tin oxide (ITO), indium tungsten oxide (IWO), indium cerium oxide (ICO), and aluminum zinc oxide (AZO). Further, the first electrode 40 is disposed in contact with the first transparent conductive layer 302.

[0084] The HJT battery provided in this embodiment includes a silicon substrate, a first intrinsic layer, a first doped layer, a first transparent conductive layer and a first electrode. Since the oxygen precipitation areas of the silicon substrate are arranged at intervals along the first direction, the annular or spiral "black ring" distributed radially in the related art will not appear. Furthermore, the first electrode includes a plurality of first gate lines, and the projection of at least one first gate line toward the silicon substrate corresponds to at least partially overlapping with the oxygen precipitation area. Since the first gate line is black under PL or EL detection, when the projection of the first gate line toward the silicon substrate corresponds to at least partially overlapping with the oxygen precipitation area, the area of ​​the oxygen precipitation area can be minimized, thereby improving the quality inspection pass rate of the HJT battery.

[0085] FIG8 is a cross-sectional schematic diagram of an HJT cell in another embodiment. Referring to FIG8 , optionally, the solar cell is based on the aforementioned HJT cell, and the HJT cell further includes: a second intrinsic layer 701 , a second doping layer 702 , a second transparent conductive layer 703 and a third electrode 80 .

[0086] The second intrinsic layer 701 is located on the second surface of the silicon substrate 10. The second intrinsic layer 701 may be an intrinsic amorphous silicon layer, which may be deposited by radio frequency plasma enhanced chemical vapor deposition process.

[0087] The second doping layer 702 is located on the surface of the second intrinsic layer 701 away from the silicon substrate 10. The first doping layer 203 and the second doping layer 702 have different conductivity types. Exemplarily, the first doping layer 203 is N-type doped amorphous silicon, N-type doped nanocrystal, N-type doped microcrystalline silicon or N-type doped silicon carbide; the second doping layer 702 is P-type doped amorphous silicon, P-type doped nanocrystal, P-type doped microcrystalline silicon or P-type doped silicon carbide. Exemplarily, the silicon substrate 10 may be an N-type silicon substrate, and the doping element of the second doping layer 702 thereof may be a P-type element, and the second doping layer 702 may be a P-type amorphous silicon layer to form a pn junction to form a power generation device.

[0088] The second transparent conductive layer 703 is located on the surface of the second doped layer 702 away from the second intrinsic layer 701, and is used to collect and transmit current. The material of the second transparent conductive layer 703 includes but is not limited to at least one of indium tin oxide (ITO), indium tungsten oxide (IWO), indium cerium oxide (ICO), and aluminum zinc oxide (AZO). Optionally, the materials of the first transparent conductive layer 302 and the second transparent conductive layer 703 can be the same.

[0089] The third electrode 80 is disposed in contact with the second transparent conductive layer 703, wherein the third electrode 80 includes a plurality of third gate lines, and the projection of at least one third gate line toward the silicon substrate 10 at least partially overlaps with the oxygen precipitation region 101. The third electrode 80 includes a plurality of third gate lines, and the projection of at least one third gate line toward the silicon substrate 10 at least partially overlaps with the oxygen precipitation region 101. Further, the projection of the first electrode 40 toward the silicon substrate 10 overlaps with the projection of the third electrode 80 toward the silicon substrate 10.

[0090] Optionally, the projections of the plurality of third gate lines toward the silicon substrate 10 respectively correspond to partial overlaps with the plurality of oxygen precipitation regions 101. Exemplarily, the projections of J third gate lines toward the silicon substrate 10 respectively correspond to partial overlaps with J oxygen precipitation regions 101; wherein J is a positive integer greater than or equal to 2. Generally speaking, the line width of the third gate line is less than the width of the oxygen precipitation region 101 in the first direction. It can be understood that the projections of the plurality of third gate lines toward the silicon substrate 10 respectively correspond to and fall into the plurality of oxygen precipitation regions 101.

[0091] In an embodiment of the present application, the HJT cell includes a silicon substrate, a first intrinsic layer, a first doped layer, a first transparent conductive layer, a second intrinsic layer, a second doped layer, a second transparent conductive layer, a first electrode, and a second electrode. Since the oxygen precipitation regions of the silicon substrate are arranged at intervals along the first direction, the annular or spiral "black ring" distributed radially in the related art will not appear. Further, the first electrode includes a plurality of first gate lines, and the projection of at least one first gate line toward the silicon substrate corresponds to at least partially overlapping with the oxygen precipitation region. The third electrode includes a plurality of third gate lines, and the projection of at least one third gate line toward the silicon substrate corresponds to at least partially overlapping with the oxygen precipitation region. Since the first gate line and the third gate line are black under PL or EL detection, when the projection of the first gate line and the third gate line toward the silicon substrate corresponds to at least partially overlapping with the oxygen precipitation region, the area of ​​the oxygen precipitation region can be minimized, thereby improving the quality inspection pass rate of the HJT cell.

[0092] Optionally, the first intrinsic layer 202 , the first doped layer 203 , the first transparent conductive layer 302 , the second intrinsic layer 701 , the second doped layer 702 , and the second transparent conductive layer 703 may be made of transparent film layers to avoid affecting the light incidence rate and photoelectric conversion efficiency of the photovoltaic cell.

[0093] Optionally, at least one of the first surface and the second surface of the silicon substrate 10 of the solar cell is a velvet structure, and the first doping layer 203 is arranged on the first surface, and / or the second doping layer 702 is arranged on the second surface to cover the velvet structure. Since the first doping layer 203 and / or the second doping layer 702 are arranged on the velvet structure, the first doping layer 203 and / or the second doping layer 702 at this position help to reduce the recombination at the interface where the first surface is located, thereby achieving an interface passivation effect on the surface. In addition, the velvet structure arranged on the first surface increases the light absorption area of ​​the solar cell, increases the photocurrent of the solar cell, and helps to improve the efficiency of the solar cell.

[0094] Fig. 9 is a schematic diagram of the structure of a photovoltaic module provided in Example 6 of the present application. Referring to Fig. 9, this embodiment provides a photovoltaic module 200, including at least one battery string 210, the battery string 210 includes at least two solar cells 100 in any of the aforementioned embodiments, and each solar cell 100 can be connected together by serial welding.

[0095] For example, multiple solar cells can be connected in series by welding ribbons, so that the electricity generated by a single solar cell can be collected for subsequent transmission. Of course, the solar cells can be arranged at intervals or stacked in a shingled form.

[0096] Exemplarily, the photovoltaic module 200 also includes an encapsulation layer and a cover plate (not shown), the encapsulation layer is used to cover the surface of the battery string 210, and the cover plate is used to cover the surface of the encapsulation layer away from the battery string 210. The solar cells are electrically connected in the form of a whole piece or multiple pieces to form a plurality of battery strings 210, and the plurality of battery strings 210 are electrically connected in series and / or in parallel. Specifically, in some embodiments, the plurality of battery strings 210 can be electrically connected by a conductive tape. The encapsulation layer covers the surface of the solar cell. For example, the encapsulation layer can be an organic encapsulation film such as an ethylene-vinyl acetate copolymer film, a polyethylene octene co-elastic film, or a polyethylene terephthalate film. The cover plate can be a cover plate with a light-transmitting function such as a glass cover plate, a plastic cover plate, etc.

[0097] This embodiment provides a photovoltaic system (not shown), including the aforementioned photovoltaic components. The photovoltaic system can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be used in equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is, the photovoltaic system can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

[0098] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0099] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A solar cell, characterized in that: The solar cell comprises: A silicon substrate, the silicon substrate comprising a plurality of oxygen precipitation regions arranged along a first direction and extending along a second direction, wherein interstitial oxygen content of the oxygen precipitation regions is higher than that of other regions of the silicon substrate, and the first direction intersects the second direction; An intermediate structure layer, located on the first surface of the silicon substrate; A first conductive layer, located on a surface of the intermediate structure layer away from the silicon substrate; A first electrode is arranged in contact with the first conductive layer, wherein the first electrode includes a plurality of first gate lines, and a projection of at least one of the first gate lines toward the silicon substrate at least partially overlaps with the oxygen precipitation region.

2. The solar cell according to claim 1, characterized in that The silicon substrate is formed by cutting a silicon rod along an extension direction of the silicon rod, wherein the second direction is the same as the extension direction of the silicon rod.

3. The solar cell according to claim 1, characterized in that Projections of the first gate lines toward the silicon substrate fall into the oxygen precipitation regions one by one.

4. The solar cell according to claim 1, characterized in that Along the second direction, the maximum difference of the interstitial oxygen content in the oxygen precipitation region does not exceed 2 ppma.

5. The solar cell according to claim 1, characterized in that: The intermediate structure layer includes: a tunneling oxide layer located on the first surface of the silicon substrate; The first conductive layer comprises: a first doped conductive layer, located on a surface of the tunnel oxide layer away from the silicon substrate; wherein, The solar cell further comprises: The first passivation layer is located on the surface of the doped conductive layer away from the tunneling oxide layer; wherein the first end of the first electrode passes through the first passivation layer and contacts the doped conductive layer, and the second end of the first electrode is exposed outside the first passivation layer.

6. The solar cell according to claim 5, characterized in that The solar cell further comprises: A second doped conductive layer is located on a second surface of the silicon substrate, the first surface and the second surface are arranged opposite to each other; A second passivation layer is located on a surface of the second doped conductive layer away from the silicon substrate; A second electrode is arranged in contact with the second doped conductive layer, wherein the second electrode includes a plurality of second gate lines, and a projection of at least one of the second gate lines toward the silicon substrate at least partially overlaps with the oxygen precipitation region.

7. The solar cell according to claim 1, characterized in that The intermediate structural layer comprises: A first intrinsic layer, located on a first surface of the silicon substrate; A first doping layer is located on a surface of the first intrinsic layer away from the silicon substrate; The first conductive layer comprises: The first transparent conductive layer is located on a surface of the first doped layer away from the first intrinsic layer, and the first electrode is disposed in contact with the first transparent conductive layer.

8. The solar cell according to claim 7, characterized in that: The solar cell further comprises: A second intrinsic layer is located on a second surface of the silicon substrate, wherein the first surface and the second surface are arranged opposite to each other; A second doping layer is located on a surface of the second intrinsic layer away from the silicon substrate; A second transparent conductive layer is located on a surface of the second doped layer away from the second intrinsic layer; wherein the first doped layer and the second doped layer have different conductivity types; The third electrode is arranged in contact with the second transparent conductive layer, wherein the third electrode comprises a plurality of third gate lines, and a projection of at least one of the third gate lines toward the silicon substrate at least partially overlaps with the oxygen precipitation region.

9. A photovoltaic module, characterized in that: The invention comprises at least one battery string, wherein the battery string comprises at least two solar cells according to any one of claims 1 to 8.

10. A photovoltaic system, characterized in that: Comprising the photovoltaic module as claimed in claim 9.

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