Solar cell, photovoltaic module, and method for manufacturing solar cell

Abstract

The application relates to a solar cell, a photovoltaic module and a preparation method of the solar cell. The solar cell comprises a silicon substrate, a doped semiconductor layer, a colloid layer and a current collecting electrode. The doped semiconductor layer is arranged on at least one side of the silicon substrate. The current collecting electrode is arranged on the side of the doped semiconductor layer away from the silicon substrate. The electrode extends along a first direction. The colloid layer is arranged on opposite sides of the current collecting electrode in a second direction respectively. The colloid layer covers at least part of the doped semiconductor layer. The second direction intersects the first direction. By arranging the colloid layer on the opposite sides of the current collecting electrode in the second direction, the structural stability of the solar cell can be enhanced, the surface covered by the colloid layer can be protected from mechanical damage in subsequent processes, and the electrical performance of the solar cell can be improved.

Description

Technical Field

[0001] This invention relates to the field of solar photovoltaic technology, and in particular to a solar cell, a photovoltaic module, and a method for preparing a solar cell. Background Technology

[0002] A solar cell is a device that converts light energy into electrical energy through the photoelectric effect.

[0003] In related technologies, screen printing is a conventional process for preparing electrode structures for solar cells.

[0004] However, when the electrode structure is prepared by screen printing, the solder ribbon or main grid will pull on the fine grid, causing stress concentration near the electrode structure. This not only affects the structural stability of the electrode structure and even the entire solar cell, but also affects the electrical performance of the solar cell. Summary of the Invention

[0005] In view of this, the present invention proposes a solar cell, a photovoltaic module, and a method for preparing a solar cell, aiming to partially or completely solve the technical problems of low electrode structure stability and poor electrical performance of existing solar cells.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows: In a first aspect, embodiments of the present invention provide a solar cell, the solar cell comprising a silicon substrate, a doped semiconductor layer, a colloidal layer, and a current collector electrode; The doped semiconductor layer is disposed on at least one side of the silicon substrate; The current collector electrode is disposed on the side of the doped semiconductor layer opposite to the silicon substrate; the electrode extends along a first direction; The colloidal layers are respectively disposed on opposite sides of the current collector electrode in the second direction; the colloidal layers at least partially cover the doped semiconductor layer; the second direction intersects the first direction.

[0007] Optionally, the thickness of the colloidal layer ranges from 0.3 μm to 20 μm, and preferably, the thickness of the colloidal layer ranges from 1 μm to 3 μm; the width of the colloidal layer in the second direction is greater than or equal to 1 μm, and preferably, the width of the colloidal layer in the second direction ranges from 40 μm to 70 μm.

[0008] Optionally, the thickness of the current collector electrode ranges from 0.1 μm to 20 μm, and preferably, the thickness of the current collector electrode ranges from 4 μm to 10 μm; the width of the current collector electrode in the second direction ranges from 5 μm to 500 μm.

[0009] Optionally, the ratio of the width of the current collector electrode in the second direction to the width of the colloidal layer in the second direction is in the range of 0.1-10, preferably in the range of 0.5-5.

[0010] Optionally, the peel strength of the colloidal layer is 5-120 gf / cm.

[0011] Optionally, the cross-sectional shape of the colloidal layer is trapezoidal; wherein the upper base of the trapezoid is close to the doped semiconductor layer, and the lower base of the trapezoid is away from the doped semiconductor layer; the length of the upper base is less than the length of the lower base.

[0012] Optionally, along the second direction, a gap structure is provided between at least one side of the current collector electrode and the colloidal layer.

[0013] Optionally, the solar cell further includes a first transparent conductive layer disposed between the doped semiconductor layer and the current collector electrode, and the colloidal layer disposed on the side of the first transparent conductive layer away from the doped semiconductor layer, wherein the colloidal layer at least partially covers the first transparent conductive layer. The doped semiconductor layer includes a first doped semiconductor layer and a second doped semiconductor layer, the first doped semiconductor layer and the second doped semiconductor layer having different polarities, and the first doped semiconductor layer and the second doped semiconductor layer are alternately disposed on the same side of the silicon substrate.

[0014] Optionally, the solar cell further includes a structural layer; The doped semiconductor layer includes a first doped semiconductor layer and a second doped semiconductor layer, the first doped semiconductor layer and the second doped semiconductor layer have different polarities, and the first doped semiconductor layer and the second doped semiconductor layer are disposed on opposite sides of the silicon substrate; the structural layers are respectively disposed on the side of the first doped semiconductor layer and the second doped semiconductor layer that is away from the silicon substrate. The colloidal layers are respectively disposed on the side of the structural layers that is away from the silicon substrate.

[0015] Optionally, the structural layer includes a passivation layer and an antireflection layer; The passivation layer is disposed on the side of the second doped semiconductor layer away from the silicon substrate; the antireflection layers are disposed on the side of the passivation layer away from the second doped semiconductor layer and the side of the first doped semiconductor layer away from the silicon substrate; the colloidal layers are disposed on the side of the antireflection layer away from the passivation layer and the side of the antireflection layer away from the first doped semiconductor layer. The collector electrode passes through the antireflection layer and is respectively disposed on the side of the passivation layer away from the second doped semiconductor layer and on the side of the first doped semiconductor layer away from the silicon substrate.

[0016] Optionally, the structural layer includes a second transparent conductive layer; The second transparent conductive layer is disposed on the side of the first doped semiconductor layer away from the silicon substrate and on the side of the second doped semiconductor layer away from the silicon substrate; the colloidal layer is disposed on the side of each of the second transparent conductive layers away from the silicon substrate.

[0017] Optionally, the colloidal layer includes a first colloidal layer and a second colloidal layer; the first doped semiconductor layer is disposed between the first colloidal layer and the silicon substrate, and the second doped semiconductor layer is disposed between the second colloidal layer and the silicon substrate; The surface roughness of the side of the first doped semiconductor layer facing away from the silicon substrate is less than the surface roughness of the side of the second doped semiconductor layer facing away from the silicon substrate; the width of the first colloidal layer along the second direction is less than the width of the second colloidal layer along the second direction; the first colloidal layers are spaced apart along the first direction.

[0018] Optionally, the colloidal layer has reflective particles, which include at least one of TiO2, ZrO2, Al2O3, and Nb2O5; the particle size of the reflective particles ranges from 20 nm to 1000 nm, preferably from 80 nm to 200 nm; the mass fraction of the reflective particles ranges from 1% to 25%, preferably from 5% to 15%.

[0019] Optionally, the peel strength of the colloidal layer having the reflective particles ranges from 10 to 80 gf / cm.

[0020] Optionally, the current collector electrode is prepared by mask evaporation.

[0021] Optionally, the colloidal layer covers all areas of the doped semiconductor layer on the side of the surface opposite to the silicon substrate, except for the collector electrode.

[0022] In a second aspect, embodiments of the present invention provide a photovoltaic module, the photovoltaic module including a cover plate, a back plate, and a solar cell disposed between the cover plate and the back plate; the solar cell includes the solar cell described in any of the first aspects above.

[0023] Thirdly, embodiments of the present invention provide a method for preparing a solar cell, wherein the method comprises: A doped semiconductor layer is disposed on at least one side of a silicon substrate; The colloidal layer is combined with the substrate layer to form a mask; The mask is opened to form a target opening; The mask is disposed on the side of the doped semiconductor layer opposite to the silicon substrate; A current-collecting electrode is prepared in the target opening; The substrate layer is removed to obtain the solar cell; in the solar cell, the electrode extends along a first direction, and the colloidal layer is disposed on opposite sides of the current collector electrode along a second direction; the second direction intersects the first direction.

[0024] In this embodiment, a colloidal layer is provided on opposite sides of the current collector electrode in the second direction of the solar cell. After the current collector electrode is fabricated, the colloidal layer can provide support when placing welding rods or bus electrodes, thereby reducing the pulling force on the current collector electrode, preventing stress concentration near the current collector electrode, and improving the structural stability of the solar cell. In subsequent processes, the colloidal layer can protect the surface it covers from mechanical damage, improving the yield of the solar cell. Furthermore, the colloidal layer can generate a light-trapping effect near the current collector electrode, improving the light-catching ability of the solar cell, thereby increasing the short-circuit current and enhancing the electrical performance of the solar cell. In summary, by providing a colloidal layer on opposite sides of the current collector electrode in the second direction, the structural stability of the solar cell can be enhanced, the surface covered by the colloidal layer can be protected from mechanical damage in subsequent processes, and the electrical performance of the solar cell can be improved.

[0025] The photovoltaic module and solar cell preparation method provided by the present invention have the same or similar game effects as the solar cell in the first aspect described above, and will not be repeated here.

[0026] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0028] Figure 1 A schematic diagram of the cross-sectional structure of a solar cell according to an embodiment of the present invention is shown; Figure 2 A top view of a solar cell according to an embodiment of the present invention is shown; Figure 3 A top-view microstructure diagram of a solar cell according to an embodiment of the present invention is shown; Figure 4 A top-view microstructure diagram of another solar cell according to an embodiment of the present invention is shown; Figure 5 An axonometric microstructure of a solar cell according to an embodiment of the present invention is shown; Figure 6 A SEM image of a solar cell according to an embodiment of the present invention is shown; Figure 7 A SEM image of another solar cell according to an embodiment of the present invention is shown; Figure 8 An SEM image of a colloidal layer included in a solar cell according to an embodiment of the present invention is shown. Figure 9 An SEM image of a colloidal layer included in another solar cell according to an embodiment of the present invention is shown; Figure 10 An SEM image of the colloidal layer included in another embodiment of the present invention is shown; Figure 11 An embodiment of the present invention is shown. Figure 1 A magnified view of a portion of region A in the middle; Figure 12 A schematic diagram of the cross-sectional structure of another solar cell according to an embodiment of the present invention is shown; Figure 13 A schematic cross-sectional structure diagram of another solar cell according to an embodiment of the present invention is shown; Figure 14 A top-view microstructure diagram of yet another type of solar cell according to an embodiment of the present invention is shown; Figure 15 A SEM image of yet another type of solar cell according to an embodiment of the present invention is shown; Figure 16 An SEM image of the colloidal layer included in another embodiment of the present invention is shown; Figure 17 A schematic diagram illustrating the fabrication of a current collector electrode included in a solar cell according to an embodiment of the present invention is shown; Figure 18 A top view of another solar cell structure according to an embodiment of the present invention is shown; Figure 19 A block diagram of a photovoltaic module according to an embodiment of the present invention is shown; Figure 20 A flowchart illustrating the steps of a method for fabricating a solar cell according to an embodiment of the present invention is shown.

[0029] Explanation of reference numerals in the attached figures: 1. Silicon substrate; 2. Doped semiconductor layer; 3. Current collector electrode; 4. Colloidal layer; 5. First transparent conductive layer; 6. Structural layer; 7. Mask; 8. Silicon nitride layer; 9. Silicon dioxide layer; 10. Gap structure; 21. First doped semiconductor layer; 22. Second doped semiconductor layer; 41. First colloidal layer; 42. Second colloidal layer; 61. Passivation layer; 62. Antireflection layer; 63. Second transparent conductive layer; 71. Substrate layer. Detailed Implementation

[0030] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0031] Combined with reference Figure 1 and Figure 2 ,in Figure 1 This diagram illustrates a cross-sectional structure of a solar cell provided in an embodiment of the present invention. Figure 2 This is an embodiment of the present invention. Figure 1 The diagram shows a top view of a solar cell. In a first aspect, the present invention provides a solar cell comprising a silicon substrate 1, a doped semiconductor layer 2, a colloidal layer 4, and a current collector electrode 3. The doped semiconductor layer 2 is disposed on at least one side of the silicon substrate 1. The current collector electrode 3 is disposed on the side of the doped semiconductor layer 2 facing away from the silicon substrate 1. The electrode extends along a first direction X. The colloidal layer 4 is disposed on opposite sides of the current collector electrode 3 in a second direction Y. The colloidal layer 4 at least partially covers the doped semiconductor layer 2. The second direction Y intersects the first direction X.

[0032] The solar cells provided in the embodiments of the present invention can be back contact (BC) cells, heterojunction (HJT) cells, tunnel oxide passivated contact (TOPCon) cells, etc. In the solar cells provided in the embodiments of the present invention, the positive electrode and the negative electrode can be located on the same side of the silicon substrate 1, or they can be located on opposite sides of the silicon substrate 1.

[0033] In a solar cell, the current collector 3 is used to collect photogenerated carriers, that is, to collect the current generated by the solar cell; in some embodiments, the current collector 3 is also referred to as the electrode grid.

[0034] The materials used to prepare the colloidal layer 4 can be acrylic resin, polyisobutylene, silicone, acrylic adhesive, etc. These colloidal materials themselves have a certain mechanical strength. Furthermore, specific materials can be added to the colloidal layer to enhance the light reflection performance of the colloidal layer or to further improve its mechanical strength.

[0035] The colloidal layer 4 is disposed on opposite sides of the current collector electrode 3 along the second direction Y. The end faces of the colloidal layer 4 on both sides can contact the edge of the current collector electrode 3 or be separated from the edge of the current collector electrode 3. The colloidal layer 4 along the second direction Y can cover part of the surface of the solar cell or cover the entire surface of the solar cell, except for all other parts of the current collector electrode 3.

[0036] The second direction Y intersects with the extension direction of the collector electrode 3, i.e., the first direction X. In some embodiments, the first direction X may be perpendicular to the second direction Y.

[0037] After the colloidal layer 4 is set, it can provide protection for the solar cell. In the subsequent processes of the solar cell (such as lamination encapsulation), the colloidal layer 4 can prevent the covered area from being mechanically damaged, reduce the generation of fine cracks in the solar cell, and thus improve the yield of the solar cell.

[0038] After setting the colloidal layer 4, when overlapping the busbar electrode or placing the solder ribbon, the colloidal layer 4 can support the solder ribbon or busbar electrode, preventing the cooled busbar electrode or solder ribbon from pulling on the current collector electrode 3 due to surface tension, which would affect the stability of the entire electrode structure of the solar cell.

[0039] After the colloidal layer 4 is set, an uneven structural surface will be formed near the current collector electrode 3, which will refract or reflect the light incident on the solar cell, thereby producing a light trapping effect, increasing the residence time of the light incident on the solar cell and improving the light absorption efficiency of the solar cell.

[0040] In this embodiment, a colloidal layer is provided on both sides of the current collector electrode in the second direction of the solar cell. After the current collector electrode is fabricated, the colloidal layer can provide support when placing welding rods or bus electrodes, thereby reducing the pulling force on the current collector electrode, avoiding stress concentration near the current collector electrode, and improving the structural stability of the solar cell. In subsequent solar cell fabrication processes, the colloidal layer can protect the surface it covers from mechanical damage, improving the yield of the solar cell. Furthermore, the colloidal layer can generate a light-trapping effect near the current collector electrode, improving the light-catching ability of the solar cell, thereby increasing the short-circuit current and enhancing the electrical performance of the solar cell. In summary, by providing a colloidal layer on both sides of the current collector electrode in the second direction, the structural stability of the solar cell can be enhanced, the surface covered by the colloidal layer can be protected from mechanical damage by subsequent processes, and the electrical performance of the solar cell can be improved.

[0041] Optionally, in conjunction with reference Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 and Figure 10 ,in Figure 3 This is a top-view digital micrograph of the structure near the current collector electrode 3 in a solar cell provided in an embodiment of the present invention. Figure 4 This is another top-view digital microstructure diagram of the area near the current collector electrode 3 in the solar cell provided in an embodiment of the present invention. Figure 5 This is an axonometric digital micrograph of a solar cell provided in an embodiment of the present invention. Figure 6 This is a cross-sectional view of a solar cell using a scanning electron microscope (SEM) according to an embodiment of the present invention. Figure 7 This is a SEM isometric structural diagram of a solar cell provided in an embodiment of the present invention. Figure 8 This is a SEM isometric structural diagram of the colloidal layer 4 in a solar cell provided in an embodiment of the present invention. Figure 9 This is another SEM isometric structural diagram of the colloidal layer 4 in the solar cell provided in this embodiment of the invention. Figure 10 This is another SEM isometric structural diagram of the colloidal layer 4 in the solar cell provided in an embodiment of the present invention; the thickness of the colloidal layer 4 is in the range of 0.3μm-20μm, preferably, the thickness of the colloidal layer 4 is in the range of 1μm-3μm; the width of the colloidal layer 4 in the second direction Y is greater than or equal to 1μm, preferably, the width of the colloidal layer 4 in the second direction Y is in the range of 40μm-70μm.

[0042] The thickness of colloidal layer 4 can be set from 0.3 μm to 20 μm to provide sufficient support and light reflection capability; refer to Figure 9 and Figure 10 On the surface of the solar cell, the thickness distribution of the colloidal layer 4 can be non-uniform, for example, in Figure 9 In the SEM image shown, the thickness of colloidal layer 4 locally reaches 3.38 μm. Figure 10 In the SEM image shown, the local thickness of colloidal layer 4 is 0.82 μm. To balance mechanical properties and preparation cost, the thickness range of colloidal layer 4 can preferably be set to 1 μm-3 μm.

[0043] The dimension of the colloidal layer 4 along the first direction X can be equal to the length of the current collector electrode 3 extending along the first direction X.

[0044] The width of the colloidal layer 4 along the second direction Y can be set to be greater than or equal to 1 μm, and it can extend to the edge covering the solar cell. (Refer to...) Figure 3 The widths of the colloidal layers 4 on opposite sides of the current collector 3 along the second direction Y can be different. Figure 3 The colloidal layer 4 on the left side of the view has a width of approximately 41.42 μm along the second direction Y, while the layer located on the left side of the view has a width of approximately 41.42 μm. Figure 3 The width of colloidal layer 4 on the right side of the view along the second direction Y is approximately 68.72 μm; (Refer to...) Figure 4 The widths of the colloidal layers 4 located on opposite sides of the current collector 3 along the second direction Y can be the same or approximately equal. Figure 4 The colloidal layer 4 on the left side of the view has a width of approximately 43.30 μm along the second direction Y, located at... Figure 4 The width of the colloidal layer 4 on the right side of the view along the second direction Y is approximately 42.32 μm, relative to... Figure 3 , Figure 4 The width difference of the colloidal layer 4 on opposite sides of the current collector 3 along the second direction Y is significantly smaller; (Refer to...) Figure 8 The widths of the colloidal layer 4 along the second direction Y at the two sampling locations are approximately 4.65 μm and 4.22 μm, respectively.

[0045] For the thickness of the colloidal layer 4, the distance between the surface of the colloidal layer 4 near the silicon substrate 1 and the surface away from the silicon substrate 1 is taken as the thickness of the colloidal layer 4. For cases where any surface is uneven, multiple sampling positions can be selected in the sampling area, and the average of the thicknesses measured at multiple sampling positions is taken as the thickness of the colloidal layer 4. These sampling positions can be multiple convex points, multiple concave points, or multiple concave points and convex points of equal or approximately the same number in the uneven surface. This embodiment of the invention does not limit this.

[0046] Optionally, refer to Figure 5 , Figure 6 and Figure 7 The thickness of the current collector 3 ranges from 0.1 μm to 20 μm, preferably from 4 μm to 10 μm; the width of the current collector 3 in the second direction Y ranges from 5 μm to 500 μm.

[0047] The thickness of the current collector electrode 3 can be set to 0.1 μm-20 μm. To ensure the photocurrent collection efficiency, the thickness of the current collector electrode 3 is preferably set to 4 μm-10 μm. The width of the current collector electrode 3 along the second direction Y can be set to 5 μm-500 μm. If the width of the current collector electrode 3 is too small (less than 5 μm), the contact resistance between the current collector electrode 3 and the main structure of the solar cell will be large, weakening the photoelectric conversion efficiency. If the width of the current collector electrode 3 is too large (greater than 500 μm), the fabrication cost of the current collector electrode 3 will increase. Figure 6 As shown, the thickness of the current collector 3 is approximately 9.50 μm.

[0048] To determine the thickness of the current collector electrode 3, an average of multiple sampling locations can be used to characterize the thickness of the current collector electrode 3.

[0049] Optionally, the ratio of the width of the current collector 3 in the second direction Y to the width of the colloidal layer 4 in the second direction Y is in the range of 0.1-10, preferably in the range of 0.5-5.

[0050] The ratio of the width of the current collector electrode 3 in the second direction Y to the width of the colloidal layer 4 in the second direction Y can be set to a range of 0.1-10. In order to balance the various performance aspects and manufacturing cost of the colloidal layer 4, the ratio range is preferably 0.5-5.

[0051] Combined with reference Figure 5 and Figure 6 Due to the influence of the fabrication method, the width of the current collector electrode 3 along the second direction Y will change along the thickness direction of the solar cell. When determining the width of the current collector electrode 3 in the second direction Y, the width of the side of the current collector electrode 3 closest to the silicon substrate can be selected as the width of the current collector electrode 3 in the second direction Y.

[0052] Optionally, the peel strength of the colloidal layer 4 is 5-120 gf / cm.

[0053] The peel strength of the colloidal layer 4 can be configured to be 5-120 gf / cm to ensure the connection strength between the colloidal layer 4 and the main structure of the solar cell and to prevent the colloidal layer 4 from falling off.

[0054] During the evidence collection process, a standard 90° or 180° peel tester can be used to peel the colloidal layer 4 from the adhesive surface at a set speed and angle (in solar cells, other film layers may also be set between the colloidal layer 4 and the doped semiconductor layer 2). The peel force per unit size measured is the peel strength.

[0055] The environment in which solar cells are located contains a variety of factors that can generate internal stress, including mechanical or thermal stress. If the peel strength of the colloidal layer 4 is less than 5 gf / cm, its adhesion is weak and it is very easy to warp and peel off due to thermal expansion and contraction. Setting the peel strength of the colloidal layer 4 to be greater than or equal to 5 gf / cm can ensure that the colloidal layer 4 has sufficient adhesion.

[0056] The peel strength should not be set too high. If the peel strength of the colloidal layer 4 is greater than 120 gf / cm, it is easy to generate large interlayer stress between the colloidal layer 4 and the substrate to which it is attached, which may lead to bending or even brittle fracture of the solar cell and reduce the yield of the solar cell.

[0057] Optionally, refer to Figure 11 , Figure 11 For the implementation of this invention Figure 1 A magnified schematic diagram of a portion of region A; the cross-sectional shape of the colloidal layer 4 is trapezoidal; the upper base of the trapezoid is close to the doped semiconductor layer 2, and the lower base of the trapezoid is away from the doped semiconductor layer 2; the length of the upper base is less than the length of the lower base.

[0058] In the fabrication of solar cells, an opening is created in the colloidal layer 4 using laser ablation, and then the colloidal layer 4 is bonded to the surface of the main structure of the solar cell to fabricate the current collector electrode 3. In the thickness direction of the colloidal layer 4, the side first exposed to laser irradiation adheres to the surface of the main structure of the solar cell. This side receives more laser energy, making the opening narrower on the side away from the main structure and wider on the side closer to the main structure. This results in a trapezoidal cross-sectional shape for the colloidal layer 4, with the side of the colloidal layer 4 away from the doped semiconductor layer 2 forming the lower base of the trapezoid, and the side of the colloidal layer 4 closer to the doped semiconductor layer 2 forming the upper base. The length of the lower base is greater than the length of the upper base. In some embodiments, the current collector electrode 3 fills the entire opening. At this time, the end face of the colloidal layer 4 will contact the current collector electrode 3. Since the colloidal layer 4, which is arranged on opposite sides of the current collector electrode 3 and has a trapezoidal cross-section, can not only constrain the swing of the current collector electrode 3 in the second direction Y, but also constrain the current collector electrode 3 in the solar thickness direction, thereby strengthening the fixation of the current collector electrode 3, enhancing the firmness of the current collector electrode 3, and preventing the current collector electrode 3 from peeling off.

[0059] Optionally, along the second direction Y, a gap structure is provided between at least one side of the current collector 3 and the colloidal layer 4.

[0060] Reference Figure 3 , Figure 4 and Figure 7 In some embodiments, since the current collector electrode 3 fails to completely fill the opening of the colloidal layer 4, a gap structure 10 is formed between at least one side of the current collector electrode 3 and the colloidal layer 4 along the second direction Y. The width of the gap structure 10 along the second direction Y ranges from 1 μm to 100 μm, preferably from 3 μm to 20 μm. The gap structure 10 can provide sufficient space for the current collector electrode 3 to be deposited, ensuring that the current collector electrode 3 will not be deposited in areas outside the opening of the colloidal layer 4 during the fabrication of the solar cell. Figure 3 As shown, located Figure 3 The gap structure 10 on the left side of the diagram has a width of approximately 10.81 μm and is located in... Figure 3 The width of the gap structure 10 on the right side of the diagram is approximately 13.66 μm, and for example... Figure 4 As shown, located Figure 4 In the gap structure 10 on the left side of the diagram, the widths of the two sampling positions are approximately 7.98 μm and 5.65 μm, respectively, located in... Figure 4 In the gap structure 10 on the right side of the figure, the widths of the two sampling positions are approximately 13.52 μm and 12.37 μm, respectively.

[0061] Optionally, refer to Figure 1 and Figure 2 The solar cell also includes a first transparent conductive layer 5, which is disposed between the doped semiconductor layer 2 and the current collector 3. A colloidal layer 4 is disposed on the side of the first transparent conductive layer 5 away from the doped semiconductor layer 2, and the colloidal layer 4 at least partially covers the first transparent conductive layer 5. The doped semiconductor layer 2 includes a first doped semiconductor layer 21 and a second doped semiconductor layer 22, which have different polarities. The first doped semiconductor layer 21 and the second doped semiconductor layer 22 are alternately disposed on the same side of the silicon substrate 1.

[0062] In a solar cell, the positive and negative electrodes can be placed on the same side of the silicon substrate 1. For example, the solar cell can be a BC cell. In this case, a first transparent conductive layer 5 is also provided between the colloidal layer 4 and the doped semiconductor layer 2. The material used to prepare the first transparent conductive layer 5 is transparent conductive oxide (TCO).

[0063] In the BC cell, the doped semiconductor layer 2 is divided into a first doped semiconductor layer 21 and a second doped semiconductor layer 22. The first doped semiconductor layer 21 can be an N-type semiconductor to provide electron transport for the solar cell; the second doped semiconductor layer 22 can be a P-type semiconductor to provide hole transport for the solar cell.

[0064] For the first transparent conductive layers 5 respectively disposed on the adjacent first doped semiconductor layer 21 and second doped semiconductor layer 22, a certain interval should be maintained to ensure that the two adjacent first transparent conductive layers 5 are insulated.

[0065] The first doped semiconductor layer 21 and the second doped semiconductor layer 22 are alternately disposed on the same side of the silicon substrate 1, which is generally the back surface of the solar cell. Adjacent first doped semiconductor layers 21 and 22 are insulated from each other to prevent short circuits. The sides of the first doped semiconductor layers 21 and 22 facing the silicon substrate 1 can be staggered along the thickness direction of the solar cell, and the sides of the first doped semiconductor layers 21 and 22 away from the silicon substrate 1 can also be staggered along the thickness direction of the solar cell. By staggering the first doped semiconductor layers 21 and 22 along the thickness direction, the surface area of ​​the first doped semiconductor layers 21 and 22 can be increased while maintaining insulation between them, thereby improving the efficiency of the photoelectric effect. The colloidal layers 4 located on the first doped semiconductor layers 21 and 22 can be staggered along the thickness direction of the solar cell or kept flush.

[0066] In a BC cell, a silicon nitride layer 8 may be disposed on the side of the silicon substrate 1 where the doped semiconductor layer 2 is not disposed.

[0067] Optionally, refer to Figure 12 and Figure 13 , Figure 12 This is a schematic diagram of the cross-sectional structure of a TOPCon battery. Figure 13 This is a schematic diagram of the cross-sectional structure of an HJT cell; the solar cell also includes a structural layer 6; the doped semiconductor layer 2 includes a first doped semiconductor layer 21 and a second doped semiconductor layer 22, the first doped semiconductor layer 21 and the second doped semiconductor layer 22 have different polarities, and the first doped semiconductor layer 21 and the second doped semiconductor layer 22 are disposed on opposite sides of the silicon substrate 1; the structural layer 6 is respectively disposed on the side of the first doped semiconductor layer 21 and the second doped semiconductor layer 22 that is away from the silicon substrate 1; the colloidal layer 4 is respectively disposed on the side of the structural layer 6 that is away from the silicon substrate 1.

[0068] In other embodiments, the positive and negative electrodes in the solar cell can be located on opposite sides of the solar cell's thickness direction, such as in TOPCon or HJT cells. In these cells, the doped semiconductor layer 2 is divided into a first doped semiconductor layer 21 and a second doped semiconductor layer 22. The first doped semiconductor layer 21 can be an N-type semiconductor, providing electron transport for the solar cell; the second doped semiconductor layer 22 can be a P-type semiconductor, providing hole transport for the solar cell.

[0069] The first doped semiconductor layer 21 and the second doped semiconductor layer 22 are respectively disposed on opposite sides of the silicon substrate 1. In these cells, there are multiple structural layers 6. Depending on the type of solar cell, the structural layers 6 can be further subdivided. The structural layer 6 can be disposed on the side of the first doped semiconductor layer 21 away from the silicon substrate 1, or it can be disposed on the side of the second doped semiconductor layer 22 away from the silicon substrate 1.

[0070] For the structural layer 6 disposed on the first doped semiconductor layer 21, the colloidal layer 4 may be disposed on the side of the structural layer 6 away from the first doped semiconductor layer 21. For the structural layer 6 disposed on the second doped semiconductor layer 22, the colloidal layer 4 may be disposed on the side of the structural layer 6 away from the second doped semiconductor layer 22.

[0071] Optionally, refer to Figure 12 The structural layer 6 includes a passivation layer 61 and an antireflection layer 62. The passivation layer 61 is disposed on the side of the second doped semiconductor layer 22 away from the silicon substrate 1. The antireflection layer 62 is disposed on the side of the passivation layer 61 away from the second doped semiconductor layer 22 and on the side of the first doped semiconductor layer 21 away from the silicon substrate 1. The colloidal layer 4 is disposed on the side of the antireflection layer 62 away from the passivation layer 61 and on the side of the antireflection layer 62 away from the first doped semiconductor layer 21. The collector electrode 3 passes through the antireflection layer 62 and is disposed on the side of the passivation layer 61 away from the second doped semiconductor layer 22 and on the side of the first doped semiconductor layer 21 away from the silicon substrate 1.

[0072] For a TOPCon battery, structural layer 6 may include a passivation layer 61 and an antireflection layer 62; the passivation layer 61 may be aluminum oxide (Al2O3), and the passivation layer 61 is disposed on the side of the second doped semiconductor layer 22 away from the silicon substrate 1; the antireflection layer 62 may be silicon nitride (SiNx), and may be disposed on the side of the passivation layer 61 away from the second doped semiconductor layer 22 and the side of the first doped semiconductor layer 21 away from the silicon substrate 1 respectively; the current collector 3 is configured to pass through the antireflection layer 62, wherein the current collector 3 disposed on the first doped semiconductor layer 21 is directly connected to the first doped semiconductor layer 21, and the current collector 3 disposed on the second doped semiconductor layer 22 is connected to the passivation layer 61. In this solar cell, for the antireflection layer 62 disposed on the first doped semiconductor layer 21, the colloidal layer 4 can be disposed on the side of the antireflection layer 62 away from the first doped semiconductor layer 21, and for the antireflection layer 62 disposed on the passivation layer 61, the colloidal layer 4 can be disposed on the side of the antireflection layer 62 away from the passivation layer 61.

[0073] In addition, in the TOPCon cell, a silicon dioxide layer 9 is disposed between the first doped semiconductor layer 21 and the silicon substrate 1.

[0074] Optionally, refer to Figure 13 The structural layer 6 includes a second transparent conductive layer 63; the second transparent conductive layer 63 is respectively disposed on the side of the first doped semiconductor layer 21 away from the silicon substrate 1 and the side of the second doped semiconductor layer 22 away from the silicon substrate 1; the colloidal layer 4 is respectively disposed on the side of each of the second transparent conductive layers 63 away from the silicon substrate 1.

[0075] For HJT cells, structural layer 6 can encapsulate a second transparent conductive layer 63; the second transparent conductive layer 63 can be a TCO, and there can be two second transparent conductive layers 63, respectively disposed on the side of the first doped semiconductor layer 22 away from the silicon substrate 1 and on the side of the second doped semiconductor layer 22 away from the silicon substrate 1; in this solar cell, for the second transparent conductive layer 63 disposed on the first doped semiconductor layer 21, a colloidal layer 4 can be disposed on the side of the second transparent conductive layer 63 away from the first doped semiconductor layer 21, and for the second transparent conductive layer 63 disposed on the second doped semiconductor layer 22, a colloidal layer 4 can be disposed on the side of the second transparent conductive layer 63 away from the second doped semiconductor layer 22.

[0076] Optionally, in conjunction with reference Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 , Figure 14 , Figure 15 and Figure 16,in Figure 14 This is a top-view digital micrograph of another type of solar cell in an embodiment of the present invention, and... Figure 3 and Figure 4 The difference is that, Figure 3 and Figure 4 The digital microstructure of the surface of the second doped semiconductor layer 22 (P-region) is shown. Figure 14 The digital microstructure of the surface (N region) of the first doped semiconductor layer 21 is shown. Figure 15 This is a SEM isometric view of the surface of the first doped semiconductor layer 21. Figure 16 This is an SEM isometric view of the colloidal layer 4 on the surface of the first doped semiconductor layer 21. The colloidal layer 4 includes a first colloidal layer 41 and a second colloidal layer 42. The first doped semiconductor layer 21 is disposed between the first colloidal layer 41 and the silicon substrate 1, and the second doped semiconductor layer 22 is disposed between the second colloidal layer 42 and the silicon substrate 1. The surface roughness of the side of the first doped semiconductor layer 21 facing away from the silicon substrate 1 is less than the surface roughness of the side of the second doped semiconductor layer 22 facing away from the silicon substrate 1. The width of the first colloidal layer 41 along the second direction Y is less than the width of the second colloidal layer 42 along the second direction Y. The first colloidal layers 41 are spaced apart along the first direction X.

[0077] The surface roughness of the side of the first doped semiconductor layer 21 facing away from the silicon substrate 1 is less than that of the side of the second doped semiconductor layer 22 facing away from the silicon substrate 1. This causes the first doped semiconductor layer 21 to exhibit a polished-looking structure under a microscope, while the second doped semiconductor layer 22 exhibits a textured-looking structure. Because the surface roughness of the second doped semiconductor layer 22 (P-region) is greater, and the colloidal layer 4 possesses a certain degree of fluidity due to the material used in its fabrication, it adheres more easily to the surface of the second doped semiconductor layer 22. Relatively speaking, the adhesion of the colloidal layer 4 to the surface of the first doped semiconductor layer 21 (N-region) is worse than that to the surface of the second doped semiconductor layer 22 (P-region), resulting in a smaller amount of colloidal layer 4 adhered. (Refer to...) Figure 14 As a result, the width of the first colloidal layer 41 located on the first doped semiconductor layer 21 along the second direction Y is smaller than the width of the second colloidal layer 42 located on the second doped semiconductor layer 22 along the second direction Y, and the first colloidal layer 41 is prone to intermittent breakage.

[0078] Both the first colloidal layer 41 and the second colloidal layer 42 exhibit uneven thickness distribution characteristics, such as... Figure 16 As shown, the thickness of the first colloidal layer 41 at three different sampling locations is 3.4 μm, 3.09 μm and 1.20 μm, respectively.

[0079] Optionally, the colloidal layer 4 has reflective particles, which include at least one of TiO2, ZrO2, Al2O3, and Nb2O5; the particle size of the reflective particles ranges from 20 nm to 1000 nm, preferably from 80 nm to 200 nm; the mass fraction of the reflective particles ranges from 1% to 25%, preferably from 5% to 15%.

[0080] Some of the light incident on the solar cell's light-receiving surface will penetrate the solar cell and be transmitted out from its back surface. By placing the colloidal layer 4 on both sides of the current collector 3 in the back surface, the light transmitted to the back surface of the solar cell can be reflected back into the solar cell through the interface of the colloidal layer 4 in the photogenerated carrier collection area, thereby achieving secondary absorption of light and improving the short-circuit current and photoelectric conversion efficiency of the solar cell.

[0081] Besides the colloidal layer 4 itself, its reflectivity can be enhanced by adding reflective particles. These reflective particles are generally metal oxides, including at least one of titanium dioxide (TiO2), zirconium oxide (ZrO2), aluminum oxide (Al2O3), and niobium pentoxide (Nb2O5). These reflective particles can be distributed within or on the surface of the colloidal layer 4. Through these reflective particles, the colloidal layer can reflect sunlight from the transmission solar cell back into the solar cell, improving the solar cell's optical reflectivity and enhancing its electrical performance.

[0082] The particle size of the reflective particles ranges from 20nm to 1000nm to cover all spectral bands of sunlight and ensure the reflective ability of the reflective particles to reflect sunlight. Preferably, the particle size range of the reflective particles is 80nm to 200nm to achieve a balance between reflective efficiency and manufacturing cost.

[0083] The mass fraction of reflective particles ranges from 1% to 25% to maintain a sufficient concentration and ensure that the added luminescent particles can provide better reflectivity for the colloidal layer 4. If the mass fraction of reflective particles is too low (less than 1%), there are too few reflective particles to affect the light reflection effect of the colloidal layer 4. If the mass fraction of reflective particles is too high (greater than 25%), the reflective particles are too dense and affect the adhesion of the colloidal layer 4. Preferably, the mass fraction of reflective particles ranges from 5% to 15%. Within this preferred range, the reflective particles can be evenly distributed to form an optimal "reflection network," which can ensure extremely high reflection efficiency and maintain the flatness, density, and good mechanical properties of the colloidal layer 4.

[0084] The colloidal layer 4 provided in this embodiment of the invention can be disposed on the light-receiving surface of the solar cell or on the back surface of the solar cell. For BC cells, the preferred embodiment is to dispose of the colloidal layer 4 only on the back surface of the solar cell.

[0085] Reference Figure 12 and Figure 13 For a solar cell with positive and negative electrodes respectively disposed on opposite sides of a silicon substrate 1, one possible implementation is to place a colloidal layer 4 on the back surface of the solar cell, and not place the colloidal layer 4 on the light-receiving surface of the solar cell or to minimize the size of the colloidal layer 4.

[0086] For example, in a TOPCon cell, the side where the first doped semiconductor layer 21 is located is generally the light-receiving side of the solar cell, and the side where the second doped semiconductor layer 22 is located is generally the back-lighting side of the solar cell. Therefore, the size of the colloidal layer 4 disposed on the first doped semiconductor layer 21 (including the width along the second direction Y and the thickness) should be as small as possible, or the colloidal layer 4 should not be disposed at that location.

[0087] In HJT cells, the side where the first doped semiconductor layer 21 is located is generally the light-receiving side of the solar cell, and the side where the second doped semiconductor layer 22 is located is generally the back-lighting side of the solar cell. Therefore, the size of the colloidal layer 4 (including the width along the second direction Y and the thickness) on the first doped semiconductor layer 21 should be as small as possible, or the colloidal layer 4 should not be set at that location.

[0088] Optionally, the peel strength of the colloidal layer 4 with reflective particles ranges from 10 to 80 gf / cm.

[0089] Setting the peel strength range of the colloidal layer 4 with reflective particles to 10-80 gf / cm ensures the environmental tolerance of the colloidal layer 4 after the addition of reflective particles. This peel strength range makes the colloidal layer 4 more suitable for preparation requirements, making it easier to achieve a balance between reflective performance, mechanical reliability and preparation cost.

[0090] Optionally, refer to Figure 17 , Figure 17 This is a schematic diagram of the fabrication of a current collector electrode 3 included in a solar cell according to an embodiment of the present invention; the current collector electrode 3 is fabricated by vapor deposition of a mask 7.

[0091] In the vapor deposition process of mask 7, mask 7 is first prepared, which includes a substrate layer 71 and a colloidal layer 4. After the mask 7 is prepared, a target opening is made on the mask 7, and then the mask 7 is attached to the main structure of the solar cell. The solar cell with mask 7 is then flipped so that the target opening of mask 7 faces downward. Below the target opening, the material for preparing the current collector electrode 3 is vaporized by heating, and the vaporized electrode material flies into the target opening and condenses and accumulates, thereby forming the current collector electrode 3. Due to the presence of mask 7, mask 7 can be tightly attached to the surface of the main structure of the solar cell, preventing the electrode material from penetrating and keeping the edge of the current collector electrode 3 neat. The current collector electrode 3 prepared by vapor deposition has the characteristics of high purity and high density, thus possessing good electrical performance.

[0092] Optionally, refer to Figure 18 , Figure 18 This is a top view of another solar cell structure in an embodiment of the present invention; the colloidal layer 4 covers all areas of the doped semiconductor layer 2 on the side facing away from the silicon substrate 1, except for the current collector electrode 3.

[0093] The colloidal layer 4 can extend from the edge of the current collector electrode 3 to the edge of the solar cell, meaning that the colloidal layer 4 can cover all areas of the surface of the doped semiconductor layer 2 facing away from the silicon substrate 1, except for the current collector electrode 3. This design provides all-around light reflection capability, effectively emitting light transmitted from all parts of the solar cell and maximizing the utilization of light reflection. Furthermore, due to its larger surface coverage, the colloidal layer 4 can form a complete protective surface on the main structure surface of the solar cell, maximizing its ability to resist mechanical damage during subsequent processes.

[0094] In this embodiment, a colloidal layer is provided on both sides of the current collector electrode in the second direction Y of the solar cell. After the current collector electrode is fabricated, the colloidal layer can provide support when placing welding rods or bus electrodes, thereby reducing the pulling force on the current collector electrode, avoiding stress concentration near the current collector electrode, and improving the structural stability of the solar cell. In subsequent processes, the colloidal layer can protect the surface it covers from mechanical damage, improving the yield of the solar cell. Furthermore, the colloidal layer can generate a light-trapping effect near the current collector electrode, improving the light-catching ability of the solar cell, thereby increasing the short-circuit current and enhancing the electrical performance of the solar cell. The colloidal layer can also reflect sunlight transmitted through the solar cell back into the solar cell, improving the optical reflection capability and enhancing the electrical performance of the solar cell. In summary, by providing a colloidal layer on both sides of the current collector electrode in the second direction Y, the structural stability of the solar cell can be enhanced, the surface covered by the colloidal layer can be protected from mechanical damage in subsequent processes, and the electrical performance of the solar cell can be improved.

[0095] Reference Figure 19 In a second aspect, the present invention provides a photovoltaic module, the photovoltaic module including a cover plate, a back sheet, and a battery string disposed between the cover plate and the back sheet, the battery string including a plurality of solar cells connected in series by interconnecting members; the solar cells including the solar cells as described in any of the first aspects above.

[0096] This photovoltaic module has the same or similar beneficial effects as the aforementioned solar cells, and will not be described in detail here.

[0097] Reference Figure 20 , Figure 20 A method for preparing a solar cell according to an embodiment of the present invention, for preparing the solar cell described in any of the first aspects above, the method comprising: Step 101: Deposit a doped semiconductor layer on at least one side of the silicon substrate; Step 102: Combine the colloidal layer with the substrate layer to form a mask; Step 103: Open the mask to form the target opening; Step 104: Place the mask on the side of the doped semiconductor layer opposite to the silicon substrate; Step 105: Prepare a current collecting electrode in the target opening; Step 106: Remove the substrate layer to obtain the solar cell; in the solar cell, the electrode extends along the first direction X, and the colloidal layer is disposed on opposite sides of the current collector electrode along the second direction Y; the second direction Y intersects the first direction X.

[0098] The method is described below with reference to specific embodiments. At the beginning of each of the following embodiments, a doped semiconductor layer has been disposed on a silicon substrate.

[0099] Example 1: Step 201: Prepare a mask with a thickness ranging from 8 μm to 100 μm. The mask consists of two layers: a substrate layer and a colloidal layer. The materials used to prepare the colloidal layer include, but are not limited to, acrylic resin, polyisobutylene, silicone, acrylic adhesive, etc. The peel strength of the colloidal layer ranges from 5 to 120 gf / cm, preferably 10 to 80 gf / cm, and the thickness ranges from 3 μm to 100 μm, preferably 5 μm to 20 μm. The materials used to prepare the substrate layer include, but are not limited to, polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyimide (PI), propylene oxide (PO), polyvinyl chloride (PVC), etc. The thickness of the substrate layer ranges from 2 μm to 200 μm, preferably 8 μm to 40 μm. Step 201 is equivalent to step 102 above.

[0100] Step 202: Place the mask prepared in step 201 flat on a flat platform with the colloid layer facing upwards, and activate the platform adsorption to fix the mask on the platform. The platform can be a metal platform or other platform-type platform, and has a hollow groove. The position and shape of the hollow groove are consistent with the position and shape of the current collector electrode. The platform has an adsorption function, and the adsorption pore size ranges from 0.1mm to 1.0mm, preferably from 0.12mm to 0.4mm.

[0101] Step 203: Select a high-precision laser system and import the target graphic into the laser system. This system has a machine vision auxiliary device, which enables the graphic processed by the laser system to coincide with the shape and pattern of the hollow groove in the table. The laser system has a suitable light source with a wavelength range of 355nm-10.6μm, preferably 532nm-1064nm. The working mode includes continuous laser or pulsed laser, preferably pulsed laser. The pulse width is 5ps-200ps, preferably 8ps-15ps. The repetition frequency range is 500kHz-2000kHz, preferably 800kHz-1300kHz. The power range is 10W-300W, preferably 50W-100W; the mask is scanned by laser in a single scan, the material in the processing area is removed, and a target opening is formed. The width of the target opening is between 5μm-500μm, preferably 30μm-70μm (the same width as the current collector electrode); the mask adjacent to the target opening area softens, melts, and undergoes chemical modification (molecular chain breakage) due to the influence of laser heat conduction, forming a modified area. The width of the modified area is between 5μm-100μm, preferably 40μm-70μm; steps 202 and 203 are equivalent to step 103 above.

[0102] Step 204: After capturing the positioning points on the surface of the solar cell using the camera and mechanical axis of the laser system, the solar cell is precisely aligned with the pattern processed in step 104, so that the mask is attached to the surface of the main structure of the solar cell (doped semiconductor layer), with a positioning accuracy error of less than 10μm; wherein, the colloidal layer faces the main structure of the solar cell; step 204 is equivalent to step 104 above.

[0103] Step 205: For the solar cell with a mask in step 204, a current collector electrode is fabricated at the target opening using physical vapor deposition, magnetron sputtering, evaporation, or other methods. Then, the substrate layer on the mask surface is removed, wherein at least part of the colloidal layer in the mask-modified region is retained on both sides of the current collector electrode, while the other colloidal layers are removed along with the substrate layer. This yields the solar cell provided in this embodiment of the invention. The top view structure of this solar cell is as follows: Figure 2 As shown; step 205 is equivalent to steps 105 and 106 above.

[0104] Example 2: The difference between Example 2 and Example 1 is that in step 201, a certain proportion of light-reflecting particles (TiO2) are doped into the colloidal layer. The particle size of the light-reflecting particles is between 20nm and 600nm, preferably between 80nm and 200nm, and the mass fraction of the light-reflecting particles is between 1% and 25%, preferably between 5% and 15%.

[0105] The other process steps in Example 2 are the same as those in Example 1.

[0106] Through Example 2, the colloidal layer in the prepared solar cell can have reflective particles, which enhances the light reflection capability of the colloidal layer and improves the electrical performance of the solar cell.

[0107] Example 3: The difference between Example 3 and Example 1 is that, in step 201, a certain proportion of light-reflecting particles (TiO2) are doped into the colloidal layer. The particle size of the light-reflecting particles is between 20nm and 600nm, preferably between 80nm and 200nm, and the mass fraction of the light-reflecting particles is between 1% and 25%, preferably between 5% and 15%.

[0108] The difference between Example 3 and Example 1 is that in step 203, after the target opening is formed, a laser system is used to irradiate the area on the mask that is not affected by the laser to modify it, so that all areas of the mask are modified areas. In this process, the laser power range is preferably 20W-50W.

[0109] The other steps of Example 3 are the same as those of Example 1. In step 205, when the substrate layer on the mask surface is removed, the colloidal layer in the modified region is completely retained, forming the structure as described above. Figure 18 The solar cell shown.

[0110] In this embodiment, a colloidal layer is provided on both sides of the current collector electrode in the second direction of the solar cell. After the current collector electrode is fabricated, the colloidal layer can provide support when placing welding rods or bus electrodes, thereby reducing the pulling force on the current collector electrode, avoiding stress concentration near the current collector electrode, and improving the structural stability of the solar cell. In subsequent processes, the colloidal layer can protect the surface it covers from mechanical damage, improving the yield of the solar cell. Furthermore, the colloidal layer can generate a light-trapping effect near the current collector electrode, improving the light-catching ability of the solar cell, thereby increasing the short-circuit current and enhancing the electrical performance of the solar cell. The colloidal layer can also reflect sunlight transmitted through the solar cell back into the solar cell, improving the optical reflection capability and enhancing the electrical performance of the solar cell. In summary, by providing a colloidal layer on both sides of the current collector electrode in the second direction, the structural stability of the solar cell can be enhanced, the surface covered by the colloidal layer can be protected from mechanical damage in subsequent processes, and the electrical performance of the solar cell can be improved.

[0111] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0112] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. For embodiments of devices, electronic devices, computer-readable storage media, and computer program products containing instructions, the descriptions are relatively simple because they are basically similar to the method embodiments; relevant parts can be referred to the descriptions of the method embodiments.

[0113] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A solar cell, characterized in that, The solar cell includes a silicon substrate, a doped semiconductor layer, a colloidal layer, and a current collector electrode; The doped semiconductor layer is disposed on at least one side of the silicon substrate; The current collector electrode is disposed on the side of the doped semiconductor layer away from the silicon substrate; The electrode extends along a first direction; The colloidal layers are respectively disposed on opposite sides of the current collecting electrode in the second direction; The colloidal layer at least partially covers the doped semiconductor layer; the second direction intersects the first direction.

2. The solar cell according to claim 1, characterized in that, The thickness of the colloidal layer ranges from 0.3 μm to 20 μm, preferably from 1 μm to 3 μm; the width of the colloidal layer in the second direction is greater than or equal to 1 μm, preferably from 40 μm to 70 μm.

3. The solar cell according to claim 1, characterized in that, The thickness of the current collector electrode ranges from 0.1 μm to 20 μm, preferably from 4 μm to 10 μm; the width of the current collector electrode in the second direction ranges from 5 μm to 500 μm.

4. The solar cell according to claim 1, characterized in that, The ratio of the width of the current collector electrode in the second direction to the width of the colloidal layer in the second direction is in the range of 0.1-10, preferably in the range of 0.5-5.

5. The solar cell according to claim 1, characterized in that, The peel strength of the colloidal layer is 5-120 gf / cm.

6. The solar cell according to claim 1, characterized in that, The cross-sectional shape of the colloidal layer is trapezoidal; wherein the upper base of the trapezoid is close to the doped semiconductor layer, and the lower base of the trapezoid is away from the doped semiconductor layer; the length of the upper base is less than the length of the lower base.

7. The solar cell according to claim 1, characterized in that, Along the second direction, a gap structure is provided between at least one side of the current collector electrode and the colloidal layer.

8. The solar cell according to claim 1, characterized in that, The solar cell further includes a first transparent conductive layer disposed between the doped semiconductor layer and the current collector electrode, and a colloidal layer disposed on the side of the first transparent conductive layer away from the doped semiconductor layer, and the colloidal layer at least partially covers the first transparent conductive layer. The doped semiconductor layer includes a first doped semiconductor layer and a second doped semiconductor layer, the first doped semiconductor layer and the second doped semiconductor layer having different polarities, and the first doped semiconductor layer and the second doped semiconductor layer are alternately disposed on the same side of the silicon substrate.

9. The solar cell according to claim 1, characterized in that, The solar cell also includes a structural layer; The doped semiconductor layer includes a first doped semiconductor layer and a second doped semiconductor layer, the first doped semiconductor layer and the second doped semiconductor layer have different polarities, and the first doped semiconductor layer and the second doped semiconductor layer are disposed on opposite sides of the silicon substrate; The structural layers are respectively disposed on the side of the first doped semiconductor layer and the second doped semiconductor layer that is away from the silicon substrate; The colloidal layers are respectively disposed on the side of the structural layers that is away from the silicon substrate.

10. The solar cell according to claim 9, characterized in that, The structural layer includes a passivation layer and an anti-reflection layer; The passivation layer is disposed on the side of the second doped semiconductor layer away from the silicon substrate; the antireflection layers are disposed on the side of the passivation layer away from the second doped semiconductor layer and the side of the first doped semiconductor layer away from the silicon substrate; the colloidal layers are disposed on the side of the antireflection layer away from the passivation layer and the side of the antireflection layer away from the first doped semiconductor layer. The collector electrode passes through the antireflection layer and is respectively disposed on the side of the passivation layer away from the second doped semiconductor layer and on the side of the first doped semiconductor layer away from the silicon substrate.

11. The solar cell according to claim 9, characterized in that, The structural layer includes a second transparent conductive layer; The second transparent conductive layer is disposed on the side of the first doped semiconductor layer away from the silicon substrate and on the side of the second doped semiconductor layer away from the silicon substrate; the colloidal layer is disposed on the side of each of the second transparent conductive layers away from the silicon substrate.

12. The solar cell according to claim 8, characterized in that, The colloidal layer includes a first colloidal layer and a second colloidal layer; the first doped semiconductor layer is disposed between the first colloidal layer and the silicon substrate, and the second doped semiconductor layer is disposed between the second colloidal layer and the silicon substrate; The surface roughness of the first doped semiconductor layer on the side facing away from the silicon substrate is less than the surface roughness of the second doped semiconductor layer on the side facing away from the silicon substrate. The width of the first colloidal layer along the second direction is smaller than the width of the second colloidal layer along the second direction; The first colloidal layer is spaced apart along the first direction.

13. The solar cell according to claim 1, characterized in that, The colloidal layer has reflective particles, which include at least one of TiO2, ZrO2, Al2O3, and Nb2O5; the particle size of the reflective particles ranges from 20nm to 1000nm, preferably from 80nm to 200nm; the mass fraction of the reflective particles ranges from 1% to 25%, preferably from 5% to 15%.

14. The solar cell according to claim 13, characterized in that, The peel strength of the colloidal layer containing the reflective particles ranges from 10 to 80 gf / cm.

15. The solar cell according to claim 1, characterized in that, The current collector electrode is prepared by mask evaporation.

16. The solar cell according to claim 1, characterized in that, The colloidal layer covers all areas of the doped semiconductor layer on the side of the surface facing away from the silicon substrate, except for the collector electrode.

17. A photovoltaic module, characterized in that, The photovoltaic module includes a cover plate, a back plate, and a solar cell disposed between the cover plate and the back plate; the solar cell includes the solar cell as described in any one of claims 1 to 16.

18. A method for preparing a solar cell, characterized in that, The method includes: A doped semiconductor layer is disposed on at least one side of a silicon substrate; The colloidal layer is combined with the substrate layer to form a mask; The mask is opened to form a target opening; The mask is disposed on the side of the doped semiconductor layer opposite to the silicon substrate; A current-collecting electrode is prepared in the target opening; The substrate layer is removed to obtain the solar cell; in the solar cell, the electrode extends along a first direction, and the colloidal layer is disposed on opposite sides of the current collector electrode along a second direction; the second direction intersects the first direction.

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