Solar cell, preparation method of solar cell and photovoltaic module

Abstract

The invention discloses a solar cell piece, a preparation method of the solar cell piece and a photovoltaic module, and belongs to the technical field of photovoltaic modules. The solar cell comprises a cell body, the cell body comprises a substrate, a doping layer and a passivation layer which are sequentially stacked, the passivation layer is provided with an opening, and the doping layer is exposed out of the opening; the first metal layer is filled in the opening; the metal particles are embedded in the passivation layer and are located at the position close to the opening; wherein the first metal layer and the metal particles are made of the same metal material.

Description

Technical Field

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

[0002] Solar cells are the core components of photovoltaic modules, which can convert solar energy into electrical energy. Grid lines are set on the solar cells to collect the current generated by the solar cells through the grid lines.

[0003] In the related art, a passivation layer can be stacked on the surface of a solar cell, an opening can be formed on the passivation layer by laser grooving, and then a grid line can be formed in the opening by electroplating, thereby forming a grid line on the solar cell to collect the current generated by the solar cell.

[0004] However, in the above processing method, during the laser grooving process, the energy of the laser mainly acts on the doped layer below the passivation layer. For example, if the doped layer is a polysilicon layer, the laser will have a thermal effect on the doped layer in a circle around the spot irradiation position, resulting in passivation damage to the doped layer in a circle around it, while part of the passivation layer in the circle around it is not opened, and subsequent electroplating cannot repair this part of the doped layer. Summary of the invention

[0005] The present application discloses a solar cell, a method for preparing a solar cell and a photovoltaic module, in order to solve or at least partially solve the problem existing in the prior art that, during the laser grooving process, the laser will have a thermal impact on the doping layer in a circle around the spot irradiation position, resulting in passivation damage to the doping layer in a circle around the laser, while part of the passivation layer in the circle around the laser is not opened, and subsequent electroplating cannot repair the doping layer in this part.

[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: a cell, comprising a substrate, a doping layer and a passivation layer stacked in sequence, the passivation layer being provided with an opening, the opening exposing the doping layer; a first metal layer, the first metal layer filling the opening; metal particles, the metal particles embedded in the passivation layer and located close to the opening; wherein the first metal layer and the metal particles are made of the same metal material.

[0008] In a second aspect, the present application also discloses a method for preparing a solar cell, the method comprising: providing a cell, the cell comprising a substrate, a doping layer and a passivation layer stacked in sequence; opening the passivation layer by laser irradiation so that the opening exposes the doping layer; forming a first metal layer in the opening by deposition; forming metal particles at a position of the passivation layer near the opening by deposition, wherein the first metal layer and the metal particles are made of the same metal material.

[0009] In a third aspect, the present application discloses a photovoltaic module, wherein the photovoltaic module comprises the solar cell described in the first aspect.

[0010] The present application discloses a solar cell, a method for preparing a solar cell and a photovoltaic module. The solar cell comprises a cell, and the cell comprises a substrate, a doping layer and a passivation layer stacked in sequence, the passivation layer is provided with an opening, and the opening exposes the doping layer; a first metal layer, the first metal layer is filled in the opening; metal particles, the metal particles are embedded in the passivation layer and are located near the opening; wherein the first metal layer and the metal particles are made of the same metal material.

[0011] The solar cell disclosed in the present application includes a cell, and the cell includes a substrate, a doping layer and a passivation layer stacked in sequence, and the passivation layer is provided with an opening to expose the doping layer. A first metal layer is filled in the opening, and metal particles are embedded in the position of the passivation layer near the opening, and the material of the metal particles is the same as the metal material of the first metal layer. Metal particles are embedded in the position of the passivation layer near the opening, and the passivation layer near the opening is repaired by the metal particles, so as to improve the reliability of the passivation of the doping layer near the opening, and avoid poor passivation of the doping layer at the edge of the opening. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The cross section of the solar cell described in the embodiment of the present application is shown in FIG. Figure 1 ;

[0013] Figure 2 The cross section of the solar cell described in the embodiment of the present application is shown in FIG. Figure 2 ;

[0014] Figure 3 Schematic diagram of the preparation process of the solar cell described in the embodiment of the present application Figure 1 ;

[0015] Figure 4 Schematic diagram of the preparation process of the solar cell described in the embodiment of the present application Figure 2 ;

[0016] Figure 5A scanning electron microscopic image showing the first metal layer and the metal particles in an embodiment of the present application;

[0017] Figure 6 Schematic diagram of the preparation process of the solar cell described in the embodiment of the present application Figure 3 ;

[0018] Figure 7 A scanning electron microscope image of a solar cell described in an embodiment of the present application is shown;

[0019] Figure 8 A cross-sectional view of a solar cell according to another embodiment of the present application;

[0020] Fig. 9 A cross-sectional view of a solar cell according to another embodiment of the present application;

[0021] Fig.10 A schematic diagram showing the structure of the opening described in the embodiment of the present application;

[0022] Fig.11 The preparation process of the solar cell described in the embodiment of the present application is shown in FIG. Figure 1 ;

[0023] Fig.12 The preparation process of the solar cell described in the embodiment of the present application is shown in FIG. Figure 2 .

[0024] Reference numerals:

[0025] 10: battery cell; 11: substrate; 12: doping layer; 13: passivation layer; 131: opening; 1311: first edge; 1312: second edge; 1313: first opening; 1314: second opening; 132: porous area;

[0026] 20: first metal layer;

[0027] 30: Metal particles;

[0028] 40: second metal layer;

[0029] 50: The third metal layer. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of the present invention.

[0031] It should be understood that the references to "one embodiment" or "an embodiment" throughout the specification mean that the specific features, structures, or characteristics associated with the embodiment are included in at least one embodiment of the present invention. Therefore, the references to "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0032] Reference Figure 1 , showing the cross section of the solar cell described in the embodiment of the present application Figure 1 ;reference Figure 2 , showing the cross section of the solar cell described in the embodiment of the present application Figure 2 ;reference Figure 3 , showing a schematic diagram of the preparation process of the solar cell described in the embodiment of the present application Figure 1 ;reference Figure 4 , showing a schematic diagram of the preparation process of the solar cell described in the embodiment of the present application Figure 2 ;reference Figure 5 , showing a scanning electron microscopic image of the first metal layer and the metal particles in an embodiment of the present application; referring to Figure 6 , showing a schematic diagram of the preparation process of the solar cell described in the embodiment of the present application Figure 3 ;reference Figure 7 , showing a scanning electron microscope image of the solar cell described in the embodiment of the present application; referring to Figure 8 , showing a cross-sectional view of a solar cell in another embodiment of the present application; referring to Fig. 9 , showing a cross-sectional view of a solar cell in another embodiment of the present application; referring to Fig.10 , showing a schematic structural diagram of the opening described in an embodiment of the present application.

[0033] like Figures 1 to 10 As shown, an embodiment of the present application discloses a solar cell, which includes a cell 10, the cell 10 includes a substrate 11, a doping layer 12 and a passivation layer 13 stacked in sequence, the passivation layer 13 is provided with an opening 131, the opening 131 exposes the doping layer 12; a first metal layer 20, the first metal layer 20 is filled in the opening 131; metal particles 30, the metal particles 30 are embedded in the passivation layer 13 and are located near the opening 131; wherein the first metal layer 20 and the metal particles 30 are made of the same metal material.

[0034] The present application embodiment discloses a solar cell, which is a core component of a photovoltaic module and can convert solar energy into electrical energy. The solar cell includes a cell, which can be a heterojunction cell, a tunneling oxide passivated contact cell (Thin Oxid Pass i vated Contact), referred to as a Topcon cell, or other types of cells. In the present application embodiment, there are no excessive restrictions on the specific type of solar cell. In actual applications, technicians can choose as needed.

[0035] like Figures 1 to 9 As shown, the solar cell disclosed in the embodiment of the present application includes a cell 10, a first metal layer 20 and metal particles 30. Among them, the cell 10 includes a substrate 11, a doping layer 12 and a passivation layer 13 stacked in sequence. The substrate 11 can convert solar energy into electrical energy, and the doping layer 12 can collect the current generated by the substrate 11. The passivation layer 13 blocks the doping layer 12 and the external circuit to prevent the cell 10 from short-circuiting.

[0036] The substrate 11 has a first surface and a second surface arranged opposite to each other. The first surface can be the side facing the sunlight, i.e., the front side. When the first surface is the front side, the second surface is the side facing away from the sunlight, i.e., the back side. The first surface can also be the side facing away from the sunlight, i.e., the back side. When the first surface is the back side, the second surface is the side facing the sunlight, i.e., the front side.

[0037] The doping layer 12 and the passivation layer 13 in the embodiment of the present application can be sequentially stacked on the first surface of the substrate 11, and the doping layer 12 and the passivation layer 13 can be sequentially stacked on the second surface of the substrate 11. The doping layer 12 and the passivation layer 13 can also be sequentially stacked on the first surface and the second surface of the substrate 11, respectively.

[0038] like Figure 3 and Figure 4 As shown, during the processing of the solar cell, an opening 131 is opened in the passivation layer 13, and the opening 131 penetrates the passivation layer 13, so that the doping layer 12 at the opening 131 is exposed. The first metal layer 20 is filled in the opening 131, so that the first metal layer 20 is in contact with the doping layer 12, so as to collect the current collected by the doping layer 12 and transmit it to the external circuit.

[0039] Exemplarily, during the processing of the solar cell, an opening 131 can be opened in the passivation layer 13 by laser grooving, so that the opening 131 penetrates the passivation layer 13, and the doping layer 12 at the opening 131 is exposed. In the process of laser opening, a special laser can be selected, such as a Gaussian laser or other shaping laser. The energy of the laser is lower in the edge area outside the opening 131 and close to the opening 131 (that is, the area that produces a thermal effect on the doping layer, resulting in passivation damage to the surrounding doping layer), while the energy in the opening 131 area is higher. Exemplarily, the laser energy in the peripheral area outside the opening 131 is less than 1 / 5 of the laser energy in the opening 131 area.

[0040] In addition, as another optional solution, the laser energy at the edge portion corresponding to the opening 131 can be slightly larger. For example, the laser energy of the entire laser spot (including the middle portion and the edge portion corresponding to the opening 131) can reach 2-3J / cm2, so that the thermal effect of the above-mentioned edge area close to the opening 131 is larger, thereby achieving the opening of the passivation layer 13 in the above-mentioned edge area outside the opening 131.

[0041] When the above-mentioned laser is selected, although the laser in the edge area of ​​the opening 131 will still have a thermal impact on the doping layer 12 near the opening 131 during the laser grooving process, it will also cause the passivation layer 13 near the edge area of ​​the opening 131 to produce a porous area 132, and the porous area 132 has micropores and cracks, and the width of the micropores and cracks is between 0.2μm and 1.5μm. This is conducive to exposing most of the doping layer damaged by the heat through the porous area 132, and subsequent electroplating or chemical plating and other coatings can easily repair this part of the doping layer.

[0042] like Figure 4 and Figure 6 As shown, in the embodiment of the present application, metal particles 30 are embedded in the position of the passivation layer 13 near the opening 131, and the material of the metal particles 30 is the same as the metal material of the first metal layer 20. The metal particles 30 are embedded in the porous area 132 of the passivation layer 13 near the opening 131, and the metal particles 30 fill the porous area 132 of the passivation layer 13 near the opening 131, thereby improving the reliability (repair effect) of the passivation of the doping layer 12 near the opening 131 and avoiding poor passivation of the doping layer 12 at the edge of the opening 131. Furthermore, the provision of the metal particles 60 can also enhance the adhesion of the first metal layer 20, reduce the contact resistance of the first metal layer 20, and improve the photoelectric conversion efficiency of the solar cell.

[0043] It should be noted that, in the embodiment of the present application, the first metal layer 20 can be filled in the opening 131 by electroplating or chemical plating, so that the first metal layer 20 is electrically connected to the doping layer 12. The material of the first metal layer 20 is the same as the metal material of the metal particles 30. In the process of forming the first metal layer 20, the metal particles 30 can also be formed in the porous area 132 of the passivation layer 13 near the opening 131 by electroplating, so that the metal particles 30 are embedded in the porous area 132 of the passivation layer 13. That is to say, in the embodiment of the present application, the first metal layer 20 can be filled in the opening 131 at one time by electroplating, and the metal particles 30 can be formed in the porous area 132 of the passivation layer 13 near the opening 131, so as to simplify the preparation process of the solar cell and reduce the preparation cost of the solar cell.

[0044] Of course, the above are only individual examples of specific ways to form the first metal layer 20 and the metal particles 30, and are not intended to be limiting of the present application. In the actual processing process, technicians can also select specific ways to form the first metal layer 20 and the metal particles 30 as needed.

[0045] The first metal layer 20 and the metal particles 30 in the embodiment of the present application are both conductive. For example, the first metal layer 20 can be a nickel layer, a tin layer, a copper layer, or other metal layers. The metal particles 30 are preferably nickel particles, and can also be tin particles, copper particles, or other metal particles.

[0046] The solar cell disclosed in the embodiment of the present application includes a cell 10, and the cell 10 includes a substrate 11, a doping layer 12 and a passivation layer 13 stacked in sequence, and the passivation layer 13 is provided with an opening 131 to expose the doping layer 12. The first metal layer 20 is filled in the opening 131, and metal particles 30 are embedded in the position of the passivation layer 13 near the opening 131, and the material of the metal particles 30 is the same as the metal material of the first metal layer 20. The metal particles 30 are embedded in the porous area 132 of the passivation layer 13 near the opening 131, and the porous area 132 of the passivation layer 13 near the opening 131 is repaired by the metal particles 30, so as to improve the reliability of the passivation of the doping layer 12 near the opening 131, and avoid poor passivation of the doping layer 12 at the edge of the opening 131. Furthermore, the provision of the metal particles 30 can also enhance the adhesion of the first metal layer 20, reduce the contact resistance of the first metal layer 20, and improve the photoelectric conversion efficiency of the solar cell.

[0047] Alternatively, if Figure 6 As shown, the solar cell disclosed in the embodiment of the present application further includes a second metal layer 40 , and the second metal layer 40 covers the first metal layer 20 and the metal particles 30 .

[0048] The metal particles 30 in the embodiment of the present application have various shapes.

[0049] Exemplarily, in the first case, a portion of the metal particles 30 is embedded in the passivation layer 13 and in contact with the doping layer 12, so that the metal particles 30 can also collect the current collected by the doping layer 12, and another portion of the metal particles 30 is exposed in the doping layer 12, and can be electrically connected to the second metal layer 40 covering the metal particles 30, so as to collect the current collected by the metal particles 30 through the second metal layer 40. In this case, the metal particles 30 can not only repair the passivation layer 13 at the edge of the opening 131. Moreover, the metal particles 30 are the same as the first metal layer 20, and are both electrically connected to the doping layer 12 to collect the current generated by the substrate 11.

[0050] The second type is that the metal particles 30 are entirely embedded in the passivation layer 13 , and the metal particles 30 are in contact with the doping layer 12 . In this case, the metal particles 30 are electrically connected to the doping layer 12 , but are not electrically connected to the second metal layer 40 .

[0051] Of course, the above are only individual examples of the specific forms of the metal particles 30 in the embodiments of the present application, and are not intended to be limiting of the present application. However, it should be noted that the metal particles 30 are preferably in contact with the doping layer 12, so that the doping layer 12 can be repaired and the contact performance can be improved. In actual applications, the metal particles 30 can also be in other forms, which are not listed here one by one.

[0052] like Figure 6 As shown, in the embodiment of the present application, the second metal layer 40 is covered on the surface of the first metal layer 20 and the metal particles 30, so that the current collected by the first metal layer 20 and the metal particles 30 is collected through the second metal layer 40, so as to transmit the current to the external circuit.

[0053] Furthermore, the second metal layer 40 can also fix the first metal layer 20 and the metal particles 30 , so that the first metal layer 20 can be more firmly embedded in the opening 131 , and the metal particles 30 can be more firmly embedded in the position of the passivation layer 13 close to the opening 131 .

[0054] It should be noted that the second metal layer 40 in the embodiment of the present application is conductive. Exemplarily, the second metal layer 40 can be a nickel layer, a silver layer, a tin layer, or other metal layers. The metal material of the second metal layer 40 can be the same as the metal material of the first metal layer 20, or the metal material of the second metal layer 40 can be different from the metal material of the first metal layer 20. In this regard, the embodiment of the present application does not make specific restrictions, and in actual applications, technicians can set it as needed.

[0055] Optionally, the second metal layer 40 in the embodiment of the present application is formed by printing a base metal paste, and the base metal paste is preferably a copper paste with low cost, which includes copper particles and organic materials between the copper particles, and adopts a low-temperature curing process instead of a sintering process, and the gate line finally formed also has copper particles and organic materials. When using copper paste, the preferred first metal layer 20 is a nickel layer to prevent the diffusion of copper materials into the battery cell substrate, while the organic material can maintain good connectivity with the nickel layer, and the copper particles ensure the path of electrical transmission.

[0056] The second metal layer 40 in the embodiment of the present application is conductive, and covers the first metal layer 20 and the metal particles 30. In other words, the second metal layer 40 is electrically connected to the first metal layer 20 and the metal particles 30 to collect the current collected by the first metal layer 20 and the metal particles 30, and transmit the collected current to the external circuit.

[0057] The second metal layer 40 in the embodiment of the present application includes copper particles and an organic material between the copper particles. The copper particles are fixed by the organic material so that the copper particles can be coated on the first metal layer 20 and the metal particles 30. Furthermore, copper is a common metal with a low price. The second metal layer 40 including copper particles helps to reduce the cost of the solar cell, thereby reducing the cost of the solar cell.

[0058] For example, the copper particles in the embodiment of the present application can be copper balls, which can be spherical, ellipsoidal, or other spheres. The copper particles in the embodiment of the present application can be copper sheets, copper particles with a cube structure, copper particles with a cuboid structure, or copper particles with other irregular shapes.

[0059] Of course, the above are only individual examples of the specific shapes of the copper particles in the embodiments of the present application, and are not intended to be limiting of the present application. In practical applications, the copper particles may also be copper particles of any other shapes.

[0060] Alternatively, if Figure 4 and Figure 6 As shown, the opening 131 is a continuous long strip structure, and along the first direction, the opening 131 has a first edge 1311 and a second edge 1312 that are relatively arranged; the metal particles 30 are embedded in the passivation layer 13 near the first edge 1311, and / or the metal particles 30 are embedded in the passivation layer 13 near the second edge 1312; wherein the opening 131 extends along the second direction, and the first direction intersects with the second direction.

[0061] like Figure 4 and Figure 6As shown, the opening 131 in the embodiment of the present application extends along the second direction, and has a first edge 1311 and a second edge 1312 arranged opposite to each other along the first direction. The metal particles 30 are embedded in the porous region 132 of the passivation layer 13 close to the first edge 1311, and / or, the metal particles 30 are embedded in the porous region 132 of the passivation layer 13 close to the second edge 1312. In other words, the metal particles 30 may be embedded only in the porous region 132 of the passivation layer 13 close to the first edge 1311, the metal particles 30 may be embedded only in the porous region 132 of the passivation layer 13 close to the second edge 1312, or the metal particles 30 may be embedded in both the porous region 132 of the passivation layer 13 close to the first edge 1311 and the porous region 132 of the passivation layer 13 close to the second edge 1312.

[0062] In the embodiment of the present application, metal particles 30 are embedded in the porous region 132 of the passivation layer 13 near the first edge 1311, and the porous region 132 near the first edge 1311 is repaired by the metal particles 30, thereby improving the reliability of the passivation of the doping layer 12 near the first edge 1311 and avoiding poor passivation of the doping layer 12 near the first edge 131. Furthermore, the metal particles 30 can also enhance the adhesion of the first metal layer 20 near the first edge 1311, reduce the contact resistance of the first metal layer 20 near the first edge 1311, and improve the photoelectric conversion efficiency of the solar cell.

[0063] It should be noted that the role of embedding the metal particles 30 in the porous region 132 of the passivation layer 13 near the second edge 1312 is the same as the role of embedding the metal particles 30 in the porous region 132 of the passivation layer 13 near the first edge 1311 , which will not be described in detail.

[0064] Preferably, Figure 4 and Figure 6 As shown, along the first direction, the metal particles 30 close to the first edge 1311 have a first distance from the first edge 1311, and the metal particles 30 close to the second edge 1312 have a second distance from the second edge 1312. The ratio of the width of the first opening 131 along the first direction to the maximum value of the first distance or the second distance should be between 2-10, so that the influence area of ​​the doping layer can be smaller and the passivation effect of the doping layer will not be excessively reduced. Optionally, the first distance and the second distance are both less than or equal to 20μm.

[0065] like Figure 4 and Figure 6 As shown, the opening 131 in the embodiment of the present application extends along the second direction, and has a first edge 1311 and a second edge 1312 that are oppositely arranged along the first direction.

[0066] In the embodiment of the present application, along the first direction, the first distance between the metal particles 30 near the first edge 1311 and the first edge 1311 is set to be less than or equal to 20 μm. During the laser grooving process, the laser will damage the passivation layer 13 near the first edge 1311, and a porous area 132 is formed in the passivation layer 13 near the first edge 131. In the embodiment of the present application, the first distance between the metal particles 30 near the first edge 1311 and the first edge 1311 is set to be less than or equal to 20 μm, so that the metal particles 30 can fill the porous area 132 of the passivation layer 13 near the first edge 1311, so as to fill the cracks and small holes in the porous area 132, thereby repairing the porous area 132 of the passivation layer 13 near the first edge 1311, improving the reliability of the doping layer 12 near the first edge 1311, and avoiding poor passivation of the doping layer 12 near the first edge 1311.

[0067] In the embodiment of the present application, along the first direction, the second distance between the metal particles 30 near the second edge 1312 and the second edge 1312 is set to be less than or equal to 20 μm. During the laser grooving process, the laser will damage the passivation layer 13 near the second edge 1312, and a porous area 132 will be formed in the passivation layer 13 near the second edge 1312. In the embodiment of the present application, the second distance between the metal particles 30 near the second edge 1312 and the second edge 1312 is set to be less than or equal to 20 μm, so that the metal particles 30 can fill the porous area 132 of the passivation layer 13 near the second edge 1312, so as to fill the cracks and small holes in the porous area 132, thereby repairing the porous area 132 of the passivation layer 13 near the second edge 1312, improving the reliability of the doping layer 12 near the second edge 1312, and avoiding poor passivation of the doping layer 12 near the second edge 1312.

[0068] For example, along the first direction, the first distance between the metal particles 30 close to the first edge 1311 and the first edge 1311 can be set to 2 μm, 5 μm, 10 μm, 15 μm, 20 μm, etc. Along the first direction, the second distance between the metal particles 30 close to the second edge 1312 and the second edge 1312 can be set to 3 μm, 7 μm, 12 μm, 15 μm, 20 μm, etc.

[0069] As an optional implementation, Fig. 9As shown, the opening 131 in the embodiment of the present application may also be a circular opening, and the circular opening includes a plurality of circular openings, and the plurality of circular openings are spaced apart in the passivation layer 13 and may be spaced apart in rows. An annular porous area 132 is formed in the passivation layer 13 around the circular opening. Along the radial direction of the circular hole, the distance between the metal particles 30 at the edge of the circular opening and the circular edge is less than or equal to 20 μm. Of course, the above are all examples of the specific structure of the opening 131 in the embodiment of the present application, and are not intended to be a limitation of the present application. In actual applications, technicians can set the specific structure of the opening 131 as needed. For example, the opening 131 may also be a rectangular opening, a special-shaped opening, etc.

[0070] Preferably, if Figure 4 and Figure 6 As shown, along the thickness direction of the solar cell, the metal particles 30 penetrate the passivation layer 13 and are connected to the doping layer 12 , and the metal particles 30 are at least partially exposed outside the passivation layer 13 .

[0071] As a preferred implementation mode, Figure 4 and Figure 6 As shown, a portion of the metal particles 30 in the embodiment of the present application is embedded in the passivation layer 13, abuts against the doping layer 12, and is electrically connected to the doping layer 12, so that the metal particles 30 can collect the current of the doping layer 12. Another portion of the metal particles 30 is exposed in the passivation layer 13, and the second metal layer 40 can be connected to the portion of the metal particles 30 exposed in the passivation layer 13 to collect the current collected by the metal particles 30 and transmit the current to the external circuit.

[0072] Through the above-mentioned arrangement, the current collected by the metal particles 30 can be transmitted to the external circuit to improve the photoelectric conversion efficiency of the solar cell. Furthermore, the metal particles 30 are embedded in the porous area 132 of the passivation layer 13 near the opening 131 to repair cracks and small holes in the porous area 132, improve the reliability of the passivation of the doping layer 12 near the opening 131, and avoid poor passivation of the doping layer 12 at the edge of the opening 131. In addition, the arrangement of the metal particles 30 can also enhance the adhesion of the first metal layer 20, reduce the contact resistance of the first metal layer 20, and improve the photoelectric conversion efficiency of the solar cell.

[0073] Optionally, the metal particles 30 in the embodiment of the present application are partially embedded in the passivation layer 13 and partially exposed outside the passivation layer 13 .

[0074] Of course, in the embodiment of the present application, only a portion of the metal particles 30 may be embedded in the passivation layer 13, not in contact with the doping layer 12, and the other portion may be exposed in the passivation layer 13. The metal particles 30 are embedded in the porous area 132 of the passivation layer 13 near the opening 131 to repair cracks and small holes in the porous area 132, improve the reliability of the passivation of the doping layer 12 near the opening 131, and avoid poor passivation of the doping layer 12 at the edge of the opening 131. Furthermore, the metal particles 30 can also be used to enhance the adhesion of the first metal layer 20, reduce the contact resistance of the first metal layer 20, and improve the photoelectric conversion efficiency of the solar cell.

[0075] It should be noted that, as described above, the metal particles 30 in the embodiment of the present application have various forms. The above specific configuration of the metal particles 30 is only an individual example of the specific form of the metal particles 30 and is not intended to limit the specific form of the metal particles 30.

[0076] Optionally, along the thickness direction of the solar cell, the thickness of the first metal layer 20 is greater than the thickness of the passivation layer 13 .

[0077] As an optional implementation, in the embodiment of the present application, the first metal layer 20 can be filled in the opening 131, and the metal particles 30 can be embedded in the position of the passivation layer 13 near the opening 131. The second metal layer 40 is covered on the side of the first metal layer 20 and the metal particles 30 away from the doping layer 12. Exemplarily, the first metal layer 20 can be filled with a nickel layer in the opening 131 by electroplating. The second metal layer 40 can be a base metal slurry layer formed by screen printing. The base metal slurry layer has a greater impact on the doping layer 12, and the base metal is easy to diffuse into the doping layer 12. The base metal includes materials such as copper, aluminum, and silver-clad copper.

[0078] Therefore, in the embodiment of the present application, along the thickness direction of the solar cell, the thickness of the first metal layer 20 is set to be greater than the thickness of the passivation layer 13 to prevent the second metal layer 40 from affecting the doping layer 12 and further affecting the photoelectric conversion efficiency of the solar cell.

[0079] Alternatively, if Figure 4 and Figure 6 As shown, along the thickness direction of the solar cell, the thickness of the first metal layer 20 is greater than or equal to 0.1 μm and less than or equal to 5 μm.

[0080] like Figure 4 and Figure 6As shown, in the embodiment of the present application, along the thickness direction of the solar cell, the thickness of the first metal layer 20 is set to be greater than or equal to 0.1 μm and less than or equal to 5 μm. The first metal layer 20 can be embedded in the opening 131, or most of the first metal layer 20 can be embedded in the opening 131, and the first metal layer 20 is fixed by the first edge 1311 and the second edge 1312 of the opening 131, so as to enhance the adhesion of the first metal layer 20, reduce the contact resistance of the first metal layer 20, and improve the photoelectric conversion efficiency of the solar cell.

[0081] For example, along the thickness direction of the solar cell, the thickness of the first metal layer 20 can be set to 0.1 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, etc. Of course, the above values ​​are only individual examples of the thickness of the first metal layer 20 and are not intended to be limiting of the present application. In actual applications, technicians can set the thickness of the first metal layer 20 to any value greater than or equal to 0.1 μm and less than or equal to 5 μm as needed.

[0082] Optionally, the metal material of the first metal layer 20 and the metal particles 30 in the embodiment of the present application includes at least one of nickel, tin, gold, silver, copper, chromium, titanium, and aluminum.

[0083] The first metal layer 20 in the embodiment of the present application may be a nickel layer, a tin layer, a gold layer, a silver layer, a copper layer, a chromium layer, a titanium layer, or an aluminum layer. It is understood that the first metal layer 20 may include only one layer or multiple layers. Exemplarily, the first metal layer 20 may include two layers, one of which is a nickel layer and the other is a copper layer.

[0084] The metal particles 30 in the embodiment of the present application can be nickel particles, tin particles, gold particles, silver particles, copper particles, chromium particles, titanium particles, or aluminum particles. It can be understood that the metal particles 30 include a plurality of metal particles 30, and the materials of the plurality of metal particles 30 are the same.

[0085] In addition, in the embodiment of the present application, there is no limitation on the specific shape of the metal particles 30. In the actual forming process, the metal particles 30 can have a variety of shapes. For example, the metal particles 30 can be cylindrical, cubic, cuboid, or any other irregular shape.

[0086] Alternatively, if Figure 6 As shown, along the thickness direction of the solar cell, the thickness of the second metal layer 40 is greater than or equal to 0.5 μm and less than or equal to 30 μm.

[0087] like Figure 6As shown, in the embodiment of the present application, along the thickness direction of the solar cell, the thickness of the second metal layer 40 is set to be greater than or equal to 0.5 μm and less than or equal to 30 μm. The first metal layer 20 and the metal particles 30 are fixed by the second metal layer 40, so that the first metal layer 20 can be more firmly embedded in the opening 131, and the metal particles 30 can be more firmly embedded in the position of the passivation layer 13 close to the opening 131.

[0088] For example, along the thickness direction of the solar cell, the thickness of the second metal layer 40 can be set to 0.5 μm, 0.7 μm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, etc. Of course, the above values ​​are only individual examples of the thickness of the second metal layer 40 and are not intended to be limiting of the present application. In actual applications, technicians can set the thickness of the second metal layer 40 to any value greater than or equal to 0.5 μm and less than or equal to 30 μm as needed.

[0089] Optionally, the second metal layer 40 includes at least one of a nickel layer, a silver layer, a tin layer, a gold layer, a copper layer, and a chromium layer, which can be formed by a plating process such as electroplating or chemical plating.

[0090] The second metal layer 40 in the embodiment of the present application may be a nickel layer, a tin layer, a gold layer, a silver layer, a copper layer, or a chromium layer. It is understood that the second metal layer 40 may include only one layer or multiple layers. Exemplarily, the second metal layer 40 may include only one layer, and the second metal layer 40 is a copper layer. The second metal layer 40 may also include two layers, one of which is a tin layer and the other is a copper layer.

[0091] Alternatively, if Figure 6 As shown, the solar cell in the embodiment of the present application further includes a third metal layer 50 , wherein the third metal layer 50 covers a side of the second metal layer 40 away from the first metal layer 20 .

[0092] like Figure 6 As shown, the solar cell disclosed in the embodiment of the present application further includes a third metal layer 50, which covers the side of the second metal layer 40 away from the first metal layer 20. The third metal layer 50 is used to enhance the reliability of the connection between the second metal layer 40 and the electrical connection member, thereby avoiding a short circuit between the second metal layer 40 and the electrical connection member, which causes the current collected by the second metal layer 40 to be unable to be conducted to the external circuit, thereby affecting the photoelectric conversion efficiency of the solar cell.

[0093] It should be noted that the third metal layer 50 in the embodiment of the present application is conductive. Exemplarily, the third metal layer 50 can be a nickel layer, a tin layer, a silver layer, or other metal layers. The metal material of the third metal layer 50 can be the same as the metal material of the first metal layer 20, or the metal material of the third metal layer 50 can be different from the metal material of the first metal layer 20. In this regard, no specific restrictions are made in the embodiment of the present application. In actual applications, technicians can set it as needed.

[0094] Alternatively, if Figure 6 As shown, along the thickness direction of the solar cell, the thickness of the third metal layer 50 is greater than or equal to 0.005 μm and less than or equal to 5 μm.

[0095] like Figure 6 As shown, in the embodiment of the present application, along the thickness direction of the solar cell, the thickness of the third metal layer 50 is set to be greater than or equal to 0.005 μm and less than or equal to 5 μm. The reliability of the connection between the second metal layer 40 and the electrical connector is enhanced through the third metal layer 50. Furthermore, the above setting can also prevent the third metal layer 50 from being too thick during the preparation of the photovoltaic module, resulting in problems such as hidden cracks in the solar cell.

[0096] For example, along the thickness direction of the solar cell, the thickness of the third metal layer 50 can be set to 0.005 μm, 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, etc. Of course, the above values ​​are only individual examples of the thickness of the third metal layer 50 and are not intended to be limiting of the present application. In actual applications, technicians can set the thickness of the third metal layer 50 to any value greater than or equal to 0.005 μm and less than or equal to 5 μm as needed.

[0097] Optionally, the third metal layer 50 includes at least one of a nickel layer, a tin layer, a gold layer, a silver layer, a copper layer, and a chromium layer.

[0098] The third metal layer 50 in the embodiment of the present application may be a nickel layer, a tin layer, a gold layer, a silver layer, a copper layer, or a chromium layer. It is understood that the third metal layer 50 may include only one layer or multiple layers. Exemplarily, the third metal layer 50 may include only one layer, and the third metal layer 50 is a tin layer, or the third metal layer 50 is a nickel layer. The third metal layer 50 may also include two layers, one of which is a tin layer and the other is a silver layer.

[0099] Alternatively, if Figures 1 to 9 As shown, the doping layer 12 in the embodiment of the present application includes a polysilicon layer.

[0100] like Figure 1As shown, taking the solar cell as a Topcon cell as an example, the solar cell includes a tunneling layer, a doping layer 12 and a passivation layer 13 sequentially stacked on the surface of a substrate 11. It can be understood that the tunneling layer, the doping layer 12 and the passivation layer 13 can cover the first surface of the substrate 11 and / or the second surface of the substrate 11. In addition, the tunneling layer and the doping layer 12 can cover the entire surface of the substrate 11, and can also cover a local area of ​​the surface of the substrate 11.

[0101] The doped layer 12 may be a polysilicon layer, and the passivation layer 13 may be one or more of an aluminum oxide layer, a silicon oxide layer, and a silicon nitride layer. That is, the passivation layer 13 may include one layer or multiple layers. Exemplarily, the passivation layer 13 includes only one layer, which may be an aluminum oxide layer. The passivation layer 13 may include two sides, one of which is an aluminum oxide layer and the other is a silicon oxide layer.

[0102] like Figure 2 As shown, taking a solar cell as a heterojunction cell as an example, the solar cell includes a doping layer 12, a transparent conductive layer (TCO layer) and a passivation layer 13 stacked sequentially on the surface of a substrate 11. Among them, the doping layer 12 is a polycrystalline silicon layer. The passivation layer 13 can be a single-layer structure or a multi-layer structure. The passivation layer 13 can be at least one of an aluminum oxide layer, a silicon oxide layer, and a silicon nitride layer.

[0103] The doping layer 12 , the transparent conductive layer (TCO layer) and the passivation layer 13 may be stacked on the first surface of the substrate 11 , may be stacked on the second surface of the substrate 11 , or may be stacked on both the first surface and the second surface of the substrate 11 .

[0104] Optionally, the opening 131 in the embodiment of the present application includes a plurality of first openings 1313 , and the plurality of first openings 1313 all extend along the second direction and are arranged at intervals along the first direction; wherein the second direction intersects with the first direction.

[0105] In the embodiment of the present application, a plurality of first openings 1313 may be formed in the passivation layer 13 by laser grooving, each of the first openings 1313 exposing the passivation layer 12, and the plurality of first openings 1313 extend along the second direction and are spaced apart along the first direction. Each first opening 1313 is filled with the first metal layer 20 to collect the current generated by the substrate 11 through the first metal layer 20.

[0106] Of course, in the embodiment of the present application, the metal particles 30 may be embedded in the position of the passivation layer 13 close to each first opening 1313, or may be embedded in the position of the passivation layer 13 close to some of the first openings 1313. This application does not make any specific limitation to this, and in actual applications, technicians may design as needed.

[0107] Optionally, the opening 131 in the embodiment of the present application further includes at least one second opening 1314 . The second opening 1314 extends along the second direction, and the second opening 1314 intersects with the first opening 1313 .

[0108] In the embodiment of the present application, at least one second opening 1314 may be opened in the passivation layer 13 by laser grooving, the second opening 1314 exposes the passivation layer 12, the second opening 1314 extends along the second direction, and the second opening 1314 intersects with the first opening 1313. The first metal layer 20 is filled in each second opening 1314, so that the first metal layer 20 in the second opening 1314 is connected to the first metal layer 20 in the first opening 1313, so that the current collected by the first metal layer 20 in the first opening 1313 is collected and transmitted to the external circuit.

[0109] It should be noted that, in the embodiment of the present application, metal particles 30 may also be embedded in the position of the passivation layer 13 close to the second opening 1314 .

[0110] Alternatively, if Figure 8 As shown, the battery cell 10 in the embodiment of the present application has a first area and a second area, the first area includes a substrate 11, a doping layer 12 and a passivation layer 13 stacked in sequence, and the second area includes a substrate 11 and a passivation layer 13 stacked in sequence; the first metal layer 20 has a first projection in the plane where the battery cell 10 is located, and the first projection falls within the first area.

[0111] like Figure 8 As shown, the cell 10 in the embodiment of the present application has a first region A and a second region B. The cell 10 in the first region A includes a substrate 11, a doping layer 12 and a passivation layer 13 stacked in sequence, while the cell 10 in the second region B includes only the substrate 11 and the passivation layer 13. That is, only the first region A is stacked with a doping layer 12 and a metal layer to collect the current generated by the substrate 11 through the doping layer 12 and the metal layer. The second region B is not provided with a doping layer 12, and the current generated by the corresponding substrate 11 needs to be collected through the doping layer 12 and the metal layer corresponding to the adjacent first region A. The other side of the cell 10 can be an emitter region formed by an in-situ doping layer, or it can be another doping layer grown epitaxially, the doping type of the other doping layer is opposite to that of the doping layer 12, and the other doping layer can be a polycrystalline silicon layer, an amorphous silicon layer or a microcrystalline silicon layer.

[0112] Alternatively, if Fig. 9 As shown, the first region in the embodiment of the present application includes multiple first regions, all of which extend along the second direction and are spaced apart along the first direction, and the second direction intersects the first direction; along the first direction, the doping types of the doping layers 12 in two adjacent first regions are opposite.

[0113] The first region in the embodiment of the present application includes a plurality of first regions, all of which extend along the first direction and are arranged at intervals along the second direction. Each first region includes a substrate 11, a doping layer 12 and a passivation layer 13 stacked in sequence. Along the first direction, the doping types of the doping layers 12 in two adjacent first regions are opposite. It can be understood that the solar cell in the embodiment of the present application is a back-contact solar cell. The positive and negative grid lines of the solar cell are both arranged on the back of the cell. Therefore, the doping types of the doping layers 12 in two adjacent first regions A are opposite, so that one of the doping layers 12 serves as the positive electrode of the substrate 11 and the other doping layer 12 serves as the negative electrode of the substrate 11.

[0114] like Fig. 9 As shown, the doping layer 12 in the first region A1 is a P-type doping layer, and the doping layer 12 in the first region A2 is an N-type doping layer. Alternatively, the doping layer 12 in the first region A1 is an N-type doping layer, and the doping layer 12 in the first region A2 is a P-type doping layer. Optionally, the substrate 11 in the embodiment of the present application has a first surface and a second surface that are arranged opposite to each other, and the doping layer 12 and the passivation layer 13 are sequentially stacked on the first surface of the substrate 11, and / or, the doping layer 12 and the passivation layer 13 are sequentially stacked on the second surface of the substrate 11.

[0115] The substrate 11 in the embodiment of the present application has a first surface and a second surface arranged opposite to each other. The first surface can be the side facing the sunlight, that is, the front side. When the first surface is the front side, the second surface is the back side. The first surface can also be the side facing away from the sunlight, that is, the back side. When the first surface is the back side, the second surface is the front side.

[0116] Taking the first surface as the front side and the second surface as the back side as an example, the doping layer 12 and the passivation layer 13 in the embodiment of the present application can be only stacked on the second surface of the substrate 11, that is, the solar cell is a back-contact solar cell.

[0117] The doping layer 12 and the passivation layer 13 in the embodiment of the present application can be stacked on both the first surface and the second surface of the substrate 11. In other words, the solar cell is a double-sided solar cell.

[0118] The present application discloses a solar cell, which comprises a cell, wherein the cell comprises a substrate, a doping layer and a passivation layer stacked in sequence, wherein the passivation layer is provided with an opening, wherein the opening exposes the doping layer; a first metal layer, wherein the first metal layer is filled in the opening; and metal particles, wherein the metal particles are embedded in the passivation layer and are located near the opening; wherein the first metal layer and the metal particles are made of the same metal material.

[0119] The solar cell disclosed in the present application includes a cell, and the cell includes a substrate, a doping layer and a passivation layer stacked in sequence, and the passivation layer is provided with an opening to expose the doping layer. The first metal layer is filled in the opening, and metal particles are embedded in the position of the passivation layer near the opening, and the material of the metal particles is the same as the metal material of the first metal layer. Metal particles are embedded in the position of the passivation layer near the opening, and the passivation layer near the opening is repaired by the metal particles, so as to improve the reliability of the passivation of the doping layer near the opening, and avoid poor passivation of the doping layer at the edge of the opening. Furthermore, the provision of metal particles can also enhance the adhesion of the first metal layer, reduce the contact resistance of the first metal layer, and improve the photoelectric conversion efficiency of the solar cell.

[0120] Reference Fig.10 , showing the preparation process of the solar cell described in the embodiment of the present application Figure 1 .

[0121] like Figure 6 As shown, the embodiment of the present application discloses a method for preparing a solar cell, the method comprising:

[0122] 101, providing a cell 10, wherein the cell 10 includes a substrate 11, a doping layer 12 and a passivation layer 13 stacked in sequence;

[0123] In the process of preparing solar cells, it is necessary to provide a cell 10. The cell 10 is the core component of the photovoltaic module, which can convert solar energy into electrical energy. The cell 10 can be a heterojunction cell, a Topcon cell, or other types of cells. In this regard, the embodiments of the present application do not make specific restrictions, and in actual applications, technicians can choose according to needs.

[0124] like Figures 1 to 9 As shown, the cell 10 in the embodiment of the present application includes a substrate 11, a doping layer 12 and a passivation layer 13 stacked in sequence. The substrate 11 can convert solar energy into electrical energy, and the doping layer 12 can collect the current generated by the substrate 11. The passivation layer 13 blocks the doping layer 12 and the external circuit to prevent the cell 10 from short-circuiting.

[0125] The substrate 11 has a first surface and a second surface arranged opposite to each other. The first surface can be the side facing the sunlight, i.e., the front side. When the first surface is the front side, the second surface is the side facing away from the sunlight, i.e., the back side. The first surface can also be the side facing away from the sunlight, i.e., the back side. When the first surface is the back side, the second surface is the side facing the sunlight, i.e., the front side.

[0126] The doping layer 12 and the passivation layer 13 in the embodiment of the present application can be stacked on the first surface of the substrate 11 in sequence, the doping layer 12 and the passivation layer 13 can be stacked on the second surface of the substrate 11 in sequence, or the doping layer 12 and the passivation layer 13 can also be stacked on the first surface and the second surface of the substrate 11 in sequence, respectively.

[0127] 102 , opening 131 in the passivation layer 13 by laser irradiation, so that the opening 131 exposes the doping layer 12 ;

[0128] In the process of preparing the solar cell, an opening 131 is opened in the passivation layer 13 by laser grooving, so that the opening 131 penetrates the passivation layer 13, and the doping layer 12 at the opening 131 is exposed. In the process of laser opening, a special laser can be selected, for example, a Gaussian laser or other shaping laser. The energy of the laser is low in the edge area outside the opening 131 and close to the opening 131 (that is, the area that produces a thermal effect on the doping layer, resulting in a passivation damage to the surrounding doping layer), while the energy in the opening 131 area is high. Exemplarily, the laser energy in the peripheral area outside the opening 131 is less than 1 / 5 of the laser energy in the opening 131 area. In addition, as another optional solution, the laser energy in the edge portion corresponding to the opening 131 can be slightly larger, for example, the laser energy of the entire laser spot (including the middle part and the edge part corresponding to the opening 131) can be used to reach 2-3J / cm2, so that the thermal effect of the above-mentioned edge area close to the opening 131 is larger, so as to realize that the passivation layer 13 in the above-mentioned edge area outside the opening 131 is opened.

[0129] When the above-mentioned laser is selected, although the laser in the edge area of ​​the opening 131 will still have a thermal impact on the doping layer 12 near the opening 131 during the laser grooving process, it will also cause the passivation layer 13 near the edge area of ​​the opening 131 to produce a porous area 132, and the porous area 132 has micropores and cracks, and the width of the micropores and cracks is between 0.2μm and 1.5μm. This is conducive to exposing most of the doping layer damaged by the heat through the porous area 132, and subsequent electroplating or chemical plating and other coatings can easily repair this part of the doping layer.

[0130] like Figure 3As shown, in an embodiment of the present application, the passivation layer 13 can be opened by laser irradiation to form a local opening 131 on the passivation layer 13, and the opening 131 penetrates the passivation layer 13, and the doping layer 12 corresponding to the opening 131 is exposed. The laser does not completely open the passivation layer 13 at the edge of the light spot, so that a porous area 132 is formed near the opening 131 of the passivation layer 13, and the porous area 132 has micropores and cracks. And the width of the micropores and cracks is between 0.2μm and 1.5μm. Exemplarily, the width of the micropores and cracks can be 0.2μm, 0.5μm, 0.8μm, 1.0μm, 1.2μm, 1.5μm, etc.

[0131] 103 , forming a first metal layer 20 in the opening 131 by deposition;

[0132] During the preparation of the solar cell, the first metal layer 20 can be formed in the opening 131 by deposition methods such as electroplating or chemical plating, so that the first metal layer 20 is embedded in the opening 131 and electrically connected to the doping layer 12 to collect the current generated by the substrate 11.

[0133] The first metal layer 20 in the embodiment of the present application has conductivity. Exemplarily, the first metal layer 20 may be a nickel layer, a tin layer, a copper layer, or other metal layers.

[0134] It should be noted that, in the embodiment of the present application, the first metal layer 20 is formed in the opening 131 by electroplating, which is only an individual example of the specific implementation of the present application and is not intended to be a limitation of the present application. In actual applications, the first metal layer 20 can also be formed in the opening 131 by chemical vapor deposition or physical vapor deposition such as evaporation and sputtering.

[0135] 104 , forming metal particles 30 at positions of the passivation layer 13 close to the opening 131 by deposition.

[0136] In the process of preparing solar cells, metal particles 30 can also be formed near the opening 131 of the passivation layer 13 by deposition methods such as electroplating or chemical plating. In the process of deposition, continuous metal particles 30 are generated and filled in the micropores and cracks, and the width of the micropores and cracks is between 0.2μm and 1.5μm. Micropores and cracks that are too small are not easy to produce continuous metal particles 30, resulting in the metal particles 30 being unable to serve as current collection paths. Micropores and cracks that are too large will damage the doping layer 12 and cause waste of electroplating solution or other chemical plating solutions.

[0137] Furthermore, the width of the micropores and cracks results in the size of the metal particles 30 finally exposed from the passivation layer 13 being between 0.5 μm and 2 μm. The metal particles 30 can be covered by the second metal layer 40, and are connected to the second metal layer 40 to collect the current generated by the substrate 11. Moreover, the width of the second metal layer 40 is greater than the width of the opening 131, and the metal particles 30 can enhance the adhesion of the first metal layer 20, reduce the contact resistance, and improve the photoelectric conversion efficiency of the solar cell.

[0138] It should be noted that in the embodiment of the present application, the metal particles 30 are formed at the position of the passivation layer 13 near the opening 131 by electroplating, which is only an individual example of the specific implementation of the present application and is not a limitation of the present application. In actual applications, the metal particles 30 can also be formed at the position of the passivation layer 13 near the opening 131 by chemical plating, screen printing, evaporation, sputtering, etc.

[0139] In the embodiment of the present application, the metal material of the metal particles 30 is the same as the metal material of the first metal layer 20, that is, the first metal layer 20 can be formed in the opening 131 by electroplating once, and at the same time, the metal particles 30 are formed at the position of the passivation layer 13 close to the opening 131, so as to simplify the preparation process of the solar cell and reduce the preparation cost of the solar cell.

[0140] The metal particles 30 in the embodiment of the present application are conductive. For example, the metal particles 30 may be nickel particles, tin particles, copper particles, or other metal particles.

[0141] The method for preparing a solar cell disclosed in the embodiment of the present application is to open an opening 131 in the passivation layer 13 by laser grooving, so that the opening 131 exposes the doping layer 12. A first metal layer 20 is formed in the opening 131 by electroplating, and metal particles 30 are formed at a position of the passivation layer 13 near the opening 131, so that the porous area 132 of the passivation layer 13 at the edge of the opening 131 is repaired by the metal particles 30, so as to improve the reliability of the passivation of the doping layer 12 near the opening 131 and avoid poor passivation of the doping layer 12 at the edge of the opening 131. Furthermore, the provision of the metal particles 30 can also enhance the adhesion of the first metal layer 20, reduce the contact resistance of the first metal layer 20, and improve the photoelectric conversion efficiency of the solar cell.

[0142] Reference Figure 7 , showing the preparation process of the solar cell described in the embodiment of the present application Figure 2 .

[0143] like Figure 7 As shown, the embodiment of the present application discloses a method for preparing a solar cell, the method comprising:

[0144] 201, providing a cell 10, wherein the cell 10 comprises a substrate 11, a doping layer 12 and a passivation layer 13 stacked in sequence;

[0145] In the method for preparing a solar cell disclosed in the embodiment of the present application, step 201 is the same as step 101, and its beneficial effects are also the same, which will not be described in detail here.

[0146] 202 , opening 131 in the passivation layer 13 by laser irradiation, so that the opening 131 exposes the doping layer 12 ;

[0147] In the method for preparing a solar cell disclosed in the embodiment of the present application, step 202 is the same as step 102, and its beneficial effects are also the same, which will not be described in detail here.

[0148] 203 , forming a first metal layer 20 in the opening 131 by deposition;

[0149] In the method for preparing a solar cell disclosed in the embodiment of the present application, step 203 is the same as step 103, and its beneficial effects are also the same, which will not be described in detail here.

[0150] 204 , forming metal particles 30 at positions of the passivation layer 13 close to the opening 131 by deposition;

[0151] In the method for preparing a solar cell disclosed in the embodiment of the present application, step 201 is the same as step 101, and its beneficial effects are also the same, which will not be described in detail here.

[0152] 205 , forming a second metal layer 40 by deposition, and covering the first metal layer 20 and the metal particles 30 with the second metal layer 40 ;

[0153] In the embodiment of the present application, the second metal layer 40 is formed by deposition such as electroplating or chemical plating, and the first metal layer 20 and the metal particles 30 are covered by the second metal layer 40. The current collected by the first metal layer 20 and the metal particles 30 is collected by the second metal layer 40 to facilitate the transmission of the current to the external circuit.

[0154] Furthermore, the second metal layer 40 can also fix the first metal layer 20 and the metal particles 30 , so that the first metal layer 20 can be more firmly embedded in the opening 131 , and the metal particles 30 can be more firmly embedded in the position of the passivation layer 13 close to the opening 131 .

[0155] It should be noted that the second metal layer 40 in the embodiment of the present application is conductive. Exemplarily, the second metal layer 40 can be a nickel layer, a silver layer, a tin layer, or other metal layers. The material of the second metal layer 40 can be the same as the material of the first metal layer 20, or it can be different from the material of the first metal layer 20. In this regard, the embodiment of the present application does not make specific restrictions, and in actual applications, technicians can set it as needed.

[0156] In the embodiment of the present application, the second metal layer 40 may be formed by printing, and the first metal layer 20 and the metal particles 30 may be covered by the second metal layer 40 .

[0157] Of course, the above are only individual examples of specific forming methods of the second metal layer 40 in the embodiment of the present application, and are not intended to be limiting of the present application. In actual applications, technicians can select a forming method for the second metal layer 40 as needed.

[0158] It should be noted that the specific forming method of the second metal layer 40 in the embodiment of the present application includes but is not limited to one or more of electroplating, chemical plating, screen printing, evaporation, and sputtering.

[0159] 206 , forming a third metal layer 50 by deposition such as electroplating or chemical plating, and covering the second metal layer 40 with the third metal layer 50 .

[0160] In the embodiment of the present application, the third metal layer 50 is formed by deposition such as electroplating or chemical plating, and the second metal layer 40 is covered by the third metal layer 50. It can be understood that the third metal layer 50 covers the side of the second metal layer 40 away from the first metal layer 20. The third metal layer 50 is used to enhance the reliability of the connection between the second metal layer 40 and the electrical connection part, and to avoid a short circuit between the second metal layer 40 and the electrical connection part, which causes the current collected by the second metal layer 40 to be unable to be conducted to the external circuit, thereby affecting the photoelectric conversion efficiency of the solar cell.

[0161] It should be noted that the specific forming method of the third metal layer 50 in the embodiment of the present application also includes one or more of chemical plating, screen printing, evaporation, and sputtering.

[0162] The third metal layer 50 in the embodiment of the present application is conductive. Exemplarily, the third metal layer 50 can be a nickel layer, a tin layer, a silver layer, or other metal layers. The material of the third metal layer 50 can be the same as the material of the first metal layer 20, or it can be different from the material of the first metal layer 20. In this regard, in the embodiment of the present application, no specific limitation is made. In actual applications, technicians can set it as needed.

[0163] The embodiment of the present application further discloses a photovoltaic module, which includes the solar cell described in the above embodiment.

[0164] It should be noted that in the embodiment of the present application, the solar cell included in the photovoltaic module has the same structure as the solar cell described in the above embodiment, and its beneficial effects are also similar, which will not be repeated here.

[0165] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0166] Although the optional embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including optional embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0167] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity from another entity, and do not necessarily require or imply any such actual relationship or order between these entities. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such article or terminal device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the article or terminal device including the elements.

[0168] The technical solution provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. At the same time, for those skilled in the art, according to the principle and implementation mode of the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A solar cell, characterized in that: include: A cell, the cell comprising a substrate, a doping layer and a passivation layer stacked in sequence, the passivation layer being provided with an opening, the opening exposing the doping layer; a first metal layer, wherein the first metal layer is filled in the opening; Metal particles, the metal particles are embedded in the passivation layer and located near the opening; Wherein, the first metal layer and the metal particles are made of the same metal material.

2. The solar cell according to claim 1, characterized in that: The solar cell further comprises a second metal layer. The second metal layer covers the first metal layer and the metal particles.

3. The solar cell according to claim 2, characterized in that: The second metal layer includes copper particles and an organic material between the copper particles.

4. The solar cell according to claim 3, characterized in that: The copper particles include copper balls and / or copper flakes.

5. The solar cell according to claim 1, characterized in that: Along the first direction, the opening has a first edge and a second edge that are oppositely disposed; The metal particles are embedded in the passivation layer at a position close to the first edge, and / or the metal particles are embedded in the passivation layer at a position close to the second edge; The opening extends along a second direction, and the first direction intersects with the second direction.

6. The solar cell according to claim 5, characterized in that: Along the first direction, the metal particles close to the first edge have a first distance from the first edge, and the metal particles close to the second edge have a second distance from the second edge. Wherein, the first distance and the second distance are both less than or equal to 20 μm.

7. The solar cell according to claim 1, characterized in that: Along the thickness direction of the solar cell sheet, the metal particles penetrate the passivation layer and are connected to the doping layer, and the metal particles are at least partially exposed outside the passivation layer.

8. The solar cell according to claim 1, characterized in that: The metal particles are partially embedded in the passivation layer and partially exposed outside the passivation layer.

9. The solar cell according to claim 1, characterized in that: Along the thickness direction of the solar cell, the thickness of the first metal layer is greater than the thickness of the passivation layer.

10. The solar cell according to claim 1, characterized in that: Along the thickness direction of the solar cell, the thickness of the first metal layer is greater than or equal to 0.1 μm and less than or equal to 5 μm.

11. The solar cell according to claim 1, characterized in that: The metal material of the first metal layer and the metal particles includes nickel.

12. The solar cell according to claim 2, characterized in that: Along the thickness direction of the solar cell, the thickness of the second metal layer is greater than or equal to 0.5 μm and less than or equal to 30 μm.

13. The solar cell according to claim 2, characterized in that: The solar cell further comprises a third metal layer, wherein: The third metal layer covers a side of the second metal layer away from the first metal layer.

14. The solar cell according to claim 13, characterized in that: Along the thickness direction of the solar cell sheet, the thickness of the third metal layer is greater than or equal to 0.005 μm and less than or equal to 5 μm, and / or the third metal layer includes a nickel layer.

15. The solar cell according to claim 1, characterized in that: The doped layer includes a polysilicon layer.

16. The solar cell according to claim 1, characterized in that: The passivation layer includes at least one of a silicon nitride layer, an aluminum oxide layer, and a silicon oxide layer.

17. The solar cell according to claim 1, characterized in that: The opening comprises a plurality of first openings, each of which extends along the second direction and is arranged at intervals along the first direction; The second direction intersects with the first direction.

18. The solar cell according to claim 17, characterized in that: The opening further includes at least one second opening, the second opening extends along the first direction, and the second opening intersects with the first opening.

19. The solar cell according to claim 1, characterized in that: The cell has a first region and a second region, the first region includes a substrate, a doping layer and a passivation layer stacked in sequence, and the second region includes a substrate and a passivation layer stacked in sequence; The first metal layer has a first projection in the plane where the battery cell is located, and the first projection falls within the first area.

20. The solar cell according to claim 19, characterized in that: The first region includes a plurality of first regions, each of which extends along a second direction and is arranged at intervals along the first direction, and the second direction intersects with the first direction; Along the first direction, the doping types of the doping layers in two adjacent first regions are opposite.

21. The solar cell according to claim 1, characterized in that: The substrate has a first surface and a second surface that are opposite to each other, the doping layer and the passivation layer are sequentially stacked on the first surface of the substrate, and / or the doping layer and the passivation layer are sequentially stacked on the second surface of the substrate.

22. A method for preparing a solar cell, characterized in that: The method comprises: Providing a cell, the cell comprising a substrate, a doping layer and a passivation layer stacked in sequence; By means of laser irradiation, an opening is formed in the passivation layer so that the opening exposes the doping layer; forming a first metal layer in the opening by deposition; Forming metal particles at a position of the passivation layer close to the opening by deposition; Wherein, the first metal layer and the metal particles are made of the same metal material.

23. The method for preparing a solar cell according to claim 22, characterized in that: The method further comprises: A second metal layer is formed by electroplating, and the first metal layer and the metal particles are covered by the second metal layer.

24. The method for preparing a solar cell according to claim 23, characterized in that: The method further comprises: A third metal layer is formed by electroplating, and the second metal layer is covered by the third metal layer.

25. The method for preparing a solar cell according to claim 22, characterized in that: The method further comprises: A second metal layer is formed by printing, and the first metal layer and the metal particles are covered by the second metal layer.

26. A photovoltaic module, characterized in that: The photovoltaic module comprises the solar cell sheet according to any one of claims 1 to 21.

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