Solar cell, preparation method thereof and photovoltaic module

Abstract

The invention relates to the photovoltaic field, provides a solar cell and a preparation method thereof, and a photovoltaic module, and at least can improve the performance of the solar cell. The preparation method of the solar cell comprises the steps that a substrate is provided, the substrate is provided with a first side and a second side which are opposite, the substrate comprises a first region and a second region which are separated from each other, and the first side is provided with a doped semiconductor layer and a doped source layer; and performing n times of laser scanning on the first region. Wherein the n-time laser scanning meets the following conditions: the x-th laser scanning corresponds to scanning along the x-th scanning line, the (x + 1)-th laser scanning corresponds to scanning along the (x + 1)-th scanning line, the y-th laser scanning corresponds to scanning along the y-th scanning line, the y-th scanning line is located between the x-th scanning line and the (x + 1)-th scanning line, x is greater than or equal to 1 and less than n, y is different from x and is different from x + 1, and x, y and n are all any positive integers; and removing the doped source layer and the doped semiconductor layer corresponding to the first region.

Description

Cross-references to related applications

[0001] This application is a divisional application of Chinese patent application filed on October 9, 2025, with application number 202511441983.7 and entitled "Solar Cell and Preparation Method Thereof, Photovoltaic Module". Technical Field

[0002] This disclosure relates to the photovoltaic field, and in particular to a solar cell and its preparation method, and a photovoltaic module. Background Technology

[0003] As fossil fuels are gradually depleted, solar energy is becoming increasingly widely used as a new energy alternative. A solar cell is a device that converts sunlight into electrical energy. Solar cells utilize the photovoltaic principle to generate charge carriers, which are then extracted using a first electrode, thus facilitating the efficient use of electrical energy.

[0004] In the fabrication of solar cells, multiple laser scans are performed on certain film layers to modify them. However, the laser scanning settings in related solar cell fabrication methods have certain problems, resulting in poor performance of the final fabricated solar cells. Summary of the Invention

[0005] This disclosure provides a solar cell and its preparation method, as well as a photovoltaic module, which at least helps to improve the performance of the solar cell.

[0006] According to some embodiments of this disclosure, one aspect of this disclosure provides a method for fabricating a solar cell. The method includes: providing a substrate having a first side and a second side opposite to each other; the substrate including a first region and a second region separate from each other; the first side having a doped semiconductor layer and a doped source layer; the doped source layer being located on the surface of the doped semiconductor layer facing away from the second side; performing n laser scans on the first region, wherein the n laser scans satisfy: the x-th laser scan corresponds to scanning along the x-th scan line, the (x+1)-th laser scan corresponds to scanning along the (x+1)-th scan line, and the y-th laser scan corresponds to scanning along the y-th scan line, wherein the y-th scan line is located between the x-th scan line and the (x+1)-th scan line, 1 ≤ x < n, y is different from x and different from x+1, and x, y, and n are all arbitrary positive integers; and removing the doped source layer and the doped semiconductor layer corresponding to the first region.

[0007] In some embodiments, the third scan line is located between the first scan line and the second scan line.

[0008] In some embodiments, the fourth scan line is located on the side of the second scan line opposite to the third scan line.

[0009] In some embodiments, the third scan line is located on the side of the first scan line away from the second scan line, or the third scan line is located on the side of the second scan line away from the first scan line.

[0010] In some embodiments, the third scan line is located on the side of the first scan line away from the second scan line, and the fourth scan line is located between the first scan line and the second scan line; or, the third scan line is located on the side of the second scan line away from the first scan line, the fourth scan line is located between the first scan line and the second scan line, and the fifth scan line is located between the second scan line and the third scan line.

[0011] In some embodiments, the xth scanning area and the (x+1)th scanning area are spaced apart, wherein the xth scanning area is the region of the xth laser scan, and the (x+1)th scanning area is the region of the (x+1)th laser scan.

[0012] In some embodiments, the area of ​​the y-th laser scan is the y-th scan region, which is located in the interval between the x-th scan region and the x+1-th scan region, and the area of ​​the y-th scan region accounts for 80% to 100% of the area of ​​the interval region.

[0013] In some embodiments, along the first direction, the distance between the xth scan region and the (x+1)th scan region is greater than 0 and less than or equal to 520 μm.

[0014] In some embodiments, the region of the y-th laser scan is the y-th scan area, which partially overlaps with the x-th scan area and also partially overlaps with the (x+1)-th scan area.

[0015] In some embodiments, along the first direction, the width of the overlapping portion of the y-th scan region and the x-th scan region is a first width W1, and the width of the x-th scan region is a second width W2, wherein the first width W1 and the second width W2 satisfy: 0 < W1 / W2 < 0.5.

[0016] In some embodiments, 160μm≤W1≤220μm; 100μm≤W2≤500μm.

[0017] In some embodiments, along the first direction, the width of the overlapping portion of the y-th scan region and the (x+1)-th scan region is a third width W3, and the width of the (x+1)-th scan region is a fourth width W4, wherein the third width W3 and the fourth width W4 satisfy: 0 < W3 / W4 < 0.5.

[0018] In some embodiments, 160μm≤W3≤220μm; 100μm≤W4≤500μm.

[0019] In some embodiments, the power of the y-th laser scan is less than or equal to the power of the x-th laser scan, and the power of the y-th laser scan is less than or equal to the power of the (x+1)-th laser scan.

[0020] In some embodiments, the power of the xth laser scan is 1000W~2000W, the power of the (x+1)th laser scan is 1000W~2000W, and the power of the yth laser scan is 1000W~2000W.

[0021] In some embodiments, the method for removing the doped source layer and the doped semiconductor layer corresponding to the first region includes: removing the doped source layer corresponding to the first region using a first wet process; and removing the doped semiconductor layer corresponding to the first region using a second wet process.

[0022] According to some embodiments of this disclosure, another aspect of this disclosure also provides a solar cell, which is prepared by the method for preparing a solar cell described in any of the above embodiments. The solar cell includes: a substrate having a first side and a second side opposite to each other, the substrate including a first region and a second region that are separate from each other, and the second region on the first side having a doped semiconductor layer.

[0023] According to some embodiments of this disclosure, another aspect of this disclosure also provides a photovoltaic module, the photovoltaic module comprising: a battery string, which is formed by connecting multiple solar cells prepared by the method described in any of the above embodiments, or by connecting multiple solar cells as described in the above embodiments; an encapsulating film for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulating film facing away from the battery string.

[0024] The technical solutions provided in this disclosure have at least the following advantages: In the technical solution of the solar cell fabrication method provided in this disclosure, when modifying the doped source layer corresponding to the first region, the y-th scan line is located between the x-th scan line and the (x+1)-th scan line, allowing the x-th scan line and the (x+1)-th scan line to be spaced apart. Compared to the x-th scan line and the (x+1)-th scan line being adjacent, the x-th scan line and the (x+1)-th scan line being separated by the y-th scan line allows for a larger spacing between them. This reduces the heat accumulation caused by laser energy radiation between the x-th and (x+1)-th laser scans, thereby reducing the risk of part of the doped source layer turning into a molten material due to heat accumulation. This molten material is difficult to remove, and its presence affects the performance of the solar cell. Therefore, by placing the y-th scan line between the x-th and (x+1)-th scan lines, this disclosure reduces the risk of molten material forming due to heat accumulation, thus improving the performance of the solar cell. Attached Figure Description

[0025] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a substrate provided in a method for fabricating solar cells in related technologies; Figure 2 A schematic diagram of a laser line performing n laser scans in a method for fabricating solar cells in related technologies; Figure 3 A schematic diagram of a substrate provided in the method for fabricating a solar cell according to an embodiment of this disclosure; Figure 4 This is a schematic diagram of a structure for removing the doped source layer corresponding to the first region in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 5 This is a schematic diagram of a structure for removing the doped semiconductor layer corresponding to the first region in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 6 A schematic diagram of a structure for forming a first electrode in a method for fabricating a solar cell according to an embodiment of this disclosure; Figure 7A partial structural schematic diagram of the scan line for n laser scans in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 8 This is another partial structural diagram of the scan line for n laser scans in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 9 This is another partial structural schematic diagram of the scan line for n laser scans in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 10 This is another partial structural diagram of the scan line for n laser scans in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 11 A schematic diagram of the structure of the x-th scan region, the (x+1)-th scan region, and the y-th scan region in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 12 Another structural schematic diagram of the x-th scan region, the (x+1)-th scan region, and the y-th scan region in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 13 This is a schematic diagram of a scanning line for laser scanning of the doped source layer corresponding to the first region in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 14 This is another schematic diagram of the scanning line for laser scanning of the doped source layer corresponding to the first region in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 15 This is a partial three-dimensional structural diagram of a cell string in a photovoltaic module provided in an embodiment of the present disclosure; Figure 16 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in an embodiment of this disclosure.

[0027] Explanation of reference numerals in the attached figures: 100. Substrate; 110. First surface; 120. Second surface; 130. First region; 140. Second region; 101. Doped semiconductor film; 102. Doped source film; 11. First laser line; 12. Second laser line; 13. Third laser line; 200. Substrate; 210. First side; 220. Second side; 230. First region; 240. Second region; 201. Doped semiconductor layer; 202. Doped source layer; 203. First electrode; 204. First passivation layer; 21. First scan line; 22. Second scan line; 23. Third scan line; 24. Fourth scan line; 25. Fifth scan line; 26. xth scan region; 27. x+1th scan region; 28. yth scan region; 300. Solar cell; 301. Encapsulating film; 302. Cover plate; 303. Solder ribbon. Detailed Implementation

[0028] Figure 1 A schematic diagram of a substrate provided in a method for fabricating solar cells in related technologies.

[0029] refer to Figure 1 The method for fabricating a solar cell in the related technology includes: providing a substrate 100, the substrate 100 having a first surface 110 and a second surface 120 opposite to each other, the first surface 110 including a first region 130 and a second region 140 that are separate from each other, the first surface 110 having a doped semiconductor film 101 and a doped source film 102, the doped source film 102 being located on the surface of the doped semiconductor film 101 facing away from the second surface 120; and performing a modification treatment on the doped source film 102 corresponding to the first region 130, the modification treatment including n laser scans.

[0030] The n laser scans satisfy the following conditions: the x-th laser scan corresponds to scanning along the x-th laser line, the (x+1)-th laser scan corresponds to scanning along the (x+1)-th laser line, and the x-th laser line and the (x+1)-th laser line are set adjacent to each other. Where 1 ≤ x < n, and x and n are both arbitrary positive integers.

[0031] The laser line is the center line of the laser region formed by the laser spot along the scanning direction during laser scanning.

[0032] Figure 2 This is a schematic diagram of a laser line performing n laser scans in a method for fabricating solar cells in related technologies. Figure 2 In the equation, direction P represents the scanning direction of the laser spot during laser scanning. Figure 2 The direction Q (i.e., the first direction Q) is perpendicular to the scanning direction P.

[0033] refer to Figure 1 and Figure 2 Taking n=3 as an example, the second laser line 12 is located between the first laser line 11 and the third laser line 13. That is, the first laser line 11 of the first laser scan and the second laser line 12 of the second laser scan are arranged adjacently, making the distance between the first laser line 11 and the second laser line 12 in the first direction Q small. Furthermore, the energy of the laser scan radiates to a certain extent in the scanning area. After the first laser scan along the first laser line 11, the second laser scan is immediately performed along the second laser line 12 adjacent to the first laser line 11. This will cause heat accumulation between the first laser line 11 and the second laser line 12 due to the radiation of the laser scan energy. This heat accumulation will cause part of the doped source film 102 to turn into a melt, which is difficult to remove and its presence will affect the performance of the solar cell.

[0034] Therefore, the laser scanning setup in related technologies can generate molten material that affects the performance of solar cells, thus requiring improvements in solar cell performance.

[0035] In the solar cell fabrication method provided in this disclosure, when modifying the doped source layer corresponding to the first region, the y-th scan line is located between the x-th scan line and the (x+1)-th scan line, allowing the x-th scan line and the (x+1)-th scan line to be spaced apart. Compared to having the x-th scan line and the (x+1)-th scan line adjacent, the x-th scan line and the (x+1)-th scan line are separated by the y-th scan line, allowing for a larger distance between the x-th scan line and the (x+1)-th scan line in the scanning direction perpendicular to the laser scan. This reduces the heat accumulation caused by laser energy radiation between the x-th and (x+1)-th laser scans, thereby reducing the risk of part of the doped source layer turning into a molten material due to heat accumulation. This molten material is difficult to remove, and its presence affects the performance of the solar cell. Therefore, by placing the y-th scan line between the x-th and (x+1)-th scan lines, this disclosure reduces the risk of molten material due to heat accumulation, thus improving the performance of the solar cell.

[0036] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.

[0037] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0039] In the description of embodiments of this disclosure, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0040] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0041] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0042] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0043] In the description of embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Additionally, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0044] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the disclosure. However, the technical solutions claimed in this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0045] Figure 3 A schematic diagram of a substrate provided in the method for fabricating a solar cell according to an embodiment of this disclosure; Figure 4 This is a schematic diagram of a structure for removing the doped source layer corresponding to the first region in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 5 This is a schematic diagram of a structure for removing the doped semiconductor layer corresponding to the first region in the method for fabricating a solar cell provided in this embodiment of the present disclosure; Figure 6 This is a schematic diagram of a structure for forming a first electrode in a method for fabricating a solar cell according to an embodiment of the present disclosure.

[0046] Reference Figures 3 to 6 The method for fabricating a solar cell includes: providing a substrate 200, the substrate 200 having a first side 210 and a second side 220 opposite to each other, the substrate 200 including a first region 230 and a second region 240 separated from each other, the first side 210 having a doped semiconductor layer 201 and a doped source layer 202, the doped source layer 202 being located on the surface of the doped semiconductor layer 201 facing away from the second side 220; modifying the doped source layer 202 corresponding to the first region 230, the modification process including n laser scans, wherein the n laser scans satisfy: the x-th laser scan corresponds to the x-th scan... Line scanning: the (x+1)th laser scan corresponds to scanning along the (x+1)th scan line, and the yth laser scan corresponds to scanning along the yth scan line. The yth scan line is located between the xth scan line and the (x+1)th scan line, 1 ≤ x < n, y is different from x and different from x+1, and x, y and n are all arbitrary positive integers. The doped source layer 202 and the doped semiconductor layer 201 corresponding to the first region 230 are removed. The doped source layer 202 corresponding to the second region 240 is removed. The first electrode 203 is formed, and the first electrode 203 is in electrical contact with the doped semiconductor layer 201 corresponding to the second region 240.

[0047] Solar cells can be one or any combination of TOPCon (Tunnel Oxide Passivated Contact) cells, PERC (Passivated Emitter Rear Cell) cells, heterojunction cells, thin-film solar cells, and tandem cells. Thin-film solar cells include, but are not limited to, perovskite thin-film solar cells, copper indium selenide (CIGS) thin-film solar cells, gallium arsenide (GaAs) thin-film solar cells, and cadmium sulfide (CdS) thin-film solar cells. Tandem cells include, but are not limited to, perovskite cells stacked with crystalline silicon cells, perovskite cells stacked with perovskite cells, and perovskite cells stacked with thin-film cells.

[0048] The substrate 200 is used to receive incident light and generate photogenerated carriers. In some embodiments, the substrate 200 may be a semiconductor substrate.

[0049] In some embodiments, the material of the substrate 200 can be an elemental semiconductor material. Specifically, the elemental semiconductor material is composed of a single element, such as silicon or germanium. The elemental semiconductor material can be monocrystalline, polycrystalline, amorphous, or microcrystalline (a state simultaneously possessing both monocrystalline and amorphous states is called microcrystalline). For example, silicon can be at least one of monocrystalline silicon, polycrystalline silicon, amorphous silicon, and microcrystalline silicon.

[0050] In some embodiments, the substrate 200 may also be a compound semiconductor material. Common compound semiconductor materials include, but are not limited to, silicon germanide, silicon carbide, gallium arsenide, indium gallium arsenide, perovskite, cadmium telluride, copper indium selenide, etc.

[0051] The substrate 200 can also be a sapphire substrate, a silicon substrate on an insulator, or a germanium substrate on an insulator.

[0052] The substrate 200 can be an N-type semiconductor substrate or a P-type semiconductor substrate. The N-type semiconductor substrate is doped with an N-type dopant element, which can be at least one of group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As). The P-type semiconductor substrate is doped with a P-type dopant element, which can be at least one of group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0053] The substrate 200 has a first side 210 and a second side 220 opposite to each other. In some embodiments, the solar cell is a single-sided cell, in which case the first side 210 can serve as the light-receiving side of the substrate 200 for receiving incident light, and the second side 220 is the backlight side. In some embodiments, the solar cell is a bi-sided cell, in which case both the first side 210 and the second side 220 can serve as light-receiving sides and can both be used to receive incident light.

[0054] The substrate 200 includes a first region 230 and a second region 240 that are separate from each other. It should be noted that the first region 230 and the second region 240 are artificially defined regions. The first region 230 corresponds to the region in the doped source layer 202 that has undergone modification treatment, and the second region 240 corresponds to the region in the doped source layer 202 that has not undergone modification treatment. The second region 240 also corresponds to the orthographic projection region of the first electrode 203 on the substrate 200.

[0055] The first side 210 has a doped semiconductor layer 201 and a doped source layer 202.

[0056] In some embodiments, the doped semiconductor layer is part of the substrate, meaning the substrate may include the doped semiconductor layer. In other embodiments, the doped semiconductor layer 201 and the substrate 200 are two separate parts, meaning the doped semiconductor layer 201 is located on the substrate 200. Figures 3 to 6 Taking the doped semiconductor layer 201 and the substrate 200 as two separate parts as an example.

[0057] In some embodiments, the conductivity type of the dopant elements in the doped semiconductor layer 201 is different from the conductivity type of the dopant elements in the substrate 200. For example, if the dopant element type of the substrate 200 is P-type, then the dopant element type in the doped semiconductor layer 201 is N-type; if the dopant element type of the substrate 200 is N-type, then the dopant element type in the doped semiconductor layer 201 is P-type.

[0058] The material of the doped semiconductor layer 201 can be at least one of amorphous silicon, polycrystalline silicon, and silicon carbide.

[0059] The doped source layer 202 contains doped elements, and the doped elements in the doped source layer 202 can be the same as the doped elements in the doped semiconductor layer 201.

[0060] In some embodiments, the material of the doped source layer 202 may be PSG (Phosphosilicate Glass) or BSG (Borosilicate Glass).

[0061] The doped source layer 202 corresponding to the first region 230 is modified to make the modified doped source layer 202 easier to remove, so that the doped semiconductor layer 201 corresponding to the first region 230 without the protection of the doped source layer 202 can be removed. This can reduce the parasitic absorption caused by the doped semiconductor layer 201, thereby improving the performance of the solar cell.

[0062] In some embodiments, the laser used for laser processing can be a red nano laser or an infrared laser.

[0063] The scan line is the center line of the laser region formed by the laser spot along the scanning direction P during laser scanning.

[0064] The laser spot can be triangular, circular, square, or polygonal, etc.

[0065] Figure 7 This is a partial structural schematic diagram of the scan line for n laser scans in the method for fabricating a solar cell provided in this embodiment of the present disclosure.

[0066] refer to Figure 7 In some embodiments, the third scan line 23 is located between the first scan line 21 and the second scan line 22. In this case, x equals 1 and y equals 3. The third scan line's location between the first and second scan lines allows them to be spaced apart. Compared to a configuration where the first and second scan lines are adjacent, the third scan line separates the first and second scan lines, allowing for a larger distance between them in the first direction Q. This reduces heat accumulation caused by laser energy radiation between the first and second laser scans, thereby reducing the risk of molten material affecting the performance of the solar cell due to heat accumulation.

[0067] Figure 8 This is another partial structural diagram of the scan line for n laser scans in the method for fabricating a solar cell provided in this embodiment of the present disclosure.

[0068] refer to Figure 8 In some embodiments, the fourth scan line 24 is located on the side of the second scan line 22 away from the third scan line 23. In this case, n equals 4, x equals 1 and y equals 3 for the first scan line 21, the second scan line 22 and the third scan line 23, and x equals 3 and y equals 2 for the second scan line 22, the third scan line 23 and the fourth scan line 24.

[0069] Figure 9 This is another partial structural diagram of the scan line for n laser scans in the method for fabricating a solar cell provided in this embodiment of the present disclosure. Figure 10 This is another partial structural diagram of the scan line for n laser scans in the method for fabricating a solar cell provided in this embodiment of the present disclosure.

[0070] refer to Figure 3 , Figure 9 and Figure 10 In some embodiments, the third scan line 23 is located on the side of the first scan line 21 away from the second scan line 22, or the third scan line 23 is located on the side of the second scan line 22 away from the first scan line 21.

[0071] The third scan line 23 is located on the side of the first scan line 21 away from the second scan line 22. That is, the first scan line 21 separates the second scan line 22 from the third scan line 23. Compared to a situation where the second scan line 22 and the third scan line are adjacent, the second scan line 22 and the third scan line 23 are separated by the first scan line 21. The spacing between the second scan line 22 and the third scan line 23 can be larger, which can reduce the heat accumulation caused by laser energy radiation between the second and third laser scans. This reduces the risk of part of the doped source layer 202 turning into a molten material due to heat accumulation. Such molten material is difficult to remove, and its presence can affect the performance of the solar cell. Therefore, placing the third scan line 23 on the side of the first scan line 21 away from the second scan line 22 can reduce the risk of molten material due to heat accumulation, thereby improving the performance of the solar cell.

[0072] refer to Figure 3 and Figure 9 In some embodiments, the third scan line 23 is located on the side of the first scan line 21 opposite to the second scan line 22, and the fourth scan line 24 is located between the first scan line 21 and the second scan line 22. This arrangement separates the first scan line 21 and the second scan line 22 by the fourth scan line 24, the second scan line 22 and the third scan line 23 by the first scan line 21 and the second scan line 22, and the third scan line 23 and the fourth scan line 24 by the first scan line 21. This ensures that when n equals 4, the scan lines of any adjacent laser processing are separated by the scan lines of another laser processing, reducing the negative impact of heat accumulation caused by the adjacent arrangement of scan lines in adjacent laser processing on the performance of the final solar cell.

[0073] refer to Figure 3 and Figure 10 The third scan line 23 is located on the side of the second scan line 22 away from the first scan line 21. The fourth scan line 24 is located between the first scan line 21 and the second scan line 22. The fifth scan line 25 is located between the second scan line 22 and the third scan line 23. With this configuration, the first scan line 21 and the second scan line 22 are separated by the fourth scan line 24; the second scan line 22 and the third scan line 23 are separated by the fifth scan line 25; the third scan line 23 and the fourth scan line 24 are separated by the second scan line 22 and the fifth scan line 25; and the fourth scan line 24 and the fifth scan line 25 are separated by the second scan line 22. This ensures that when n equals 5, the scan lines of any adjacent laser processing are separated by the scan lines of another laser processing, reducing the negative impact of heat accumulation caused by the adjacent arrangement of scan lines in adjacent laser processing on the performance of the final solar cell.

[0074] Figure 11This is a schematic diagram of the structure of the x-th scan region, the x+1-th scan region, and the y-th scan region in the method for fabricating a solar cell provided in this embodiment of the present disclosure. Figure 12 This is another schematic diagram of the structure of the x-th scan region, the x+1-th scan region, and the y-th scan region in the method for fabricating a solar cell provided in this embodiment of the present disclosure.

[0075] in, Figure 11 and Figure 12 The difference is: Figure 11 The x-th scan region 26 and the y-th scan region 28 are separated, and the (x+1)-th scan region 27 and the y-th scan region 28 are separated; Figure 12 The x-th scan region 26 and the y-th scan region 28 partially overlap, and the (x+1)-th scan region 27 and the y-th scan region 28 partially overlap. It should be noted that... Figure 12 To better illustrate the overlapping portions of the x-th scan area 26 and the y-th scan area 28, as well as the overlapping portions of the x+1-th scan area 27 and the y-th scan area 28, perspective was applied to the x-th scan area 26, the x+1-th scan area 27, and the y-th scan area 28.

[0076] refer to Figure 3 , Figure 11 and Figure 12 In some embodiments, the x-th scan region 26 and the (x+1)-th scan region 27 are spaced apart, where the x-th scan region 26 is the region for the x-th laser scan, and the (x+1)-th scan region 27 is the region for the (x+1)-th laser scan. That is, the x-th scan region 26 and the (x+1)-th scan region 27 do not overlap. This avoids the negative impact on the performance of the final solar cell caused by heat accumulation in the overlapping area during the (x+1)-th laser scan, which would otherwise occur if the x-th scan region 26 and the (x+1)-th scan region 27 overlapped.

[0077] refer to Figure 3 and Figure 11 In some embodiments, the area of ​​the y-th laser scan is the y-th scan area 28, which is located in the interval (not labeled) between the x-th scan area 26 and the x+1-th scan area 27, and the area of ​​the y-th scan area 28 accounts for 80% to 100% of the area of ​​the interval area.

[0078] The area of ​​the y-th scan region 28 can be 80%, 85%, 90%, 95%, or 100% of the area of ​​the spacer region. Within these ranges, a larger proportion of the y-th scan region 28 to the spacer region ensures that most of the doped source layer 202 corresponding to the first region 230 is scanned by the laser, facilitating subsequent removal of the doped source layer 202 corresponding to the first region 230.

[0079] It is understandable that although the area of ​​the y-th scanning region 28 is not 100% of the area of ​​the interval region, when most of the doped source layer 202 is scanned by the laser, and the first wet process removes most of the doped source layer 202, the small portion of the doped source layer 202 corresponding to the first region 230 that is not scanned by the laser will be removed simultaneously during the first wet process. By keeping the area of ​​the y-th scanning region 28 within the range of 80% to 100% of the area of ​​the interval region, it can be ensured that most of the doped source layer 202 corresponding to the first region 230 is scanned by the laser, facilitating the subsequent removal of the doped source layer 202 corresponding to the first region 230.

[0080] In some embodiments, along the first direction Q, the distance between the xth scan region 26 and the (x+1)th scan region 27 is greater than 0 and less than or equal to 520 μm. The distance between the xth scan region 26 and the (x+1)th scan region 27 can be 1 μm, 10 μm, 20 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, or 520 μm. A distance within the above range between the xth scan region 26 and the (x+1)th scan region 27 can reduce heat accumulation between them during the (x+1)th laser scan after the xth laser scan, thereby reducing the risk of melting due to heat accumulation and improving the performance of the solar cell.

[0081] refer to Figure 3 and Figure 12 In some embodiments, the y-th scan region 28 partially overlaps with the x-th scan region 26 and also partially overlaps with the (x+1)-th scan region 27. This ensures that the y-th scan region 28 completely covers the gap between the x-th scan region 26 and the (x+1)-th scan region 27. This ensures that the doped source layer 202 corresponding to the first region 230 is completely scanned by the laser, thereby improving the reliability of solar cell fabrication.

[0082] In some embodiments, during the x-th laser scan, the energy received by the x-th scan region 26 along the first direction Q is uneven. Typically, the central portion of the x-th scan region 26 receives higher energy than the edge portions located on opposite sides of the central portion along the first direction Q. By partially overlapping the y-th scan region 28 with the x-th scan region 26, the y-th laser scan can reinforce the edge portions of the x-th scan region 26 that receive lower energy, which also helps improve the reliability of solar cell fabrication.

[0083] In some embodiments, during the (x+1)th laser scan, the energy received by the (x+1)th scan region 27 along the first direction Q is uneven. Typically, the central portion of the (x+1)th scan region 27 receives higher energy than the edge portions located on opposite sides of the central portion along the first direction Q. By partially overlapping the (y)th scan region 28 with the (x+1)th scan region 27, the (y)th laser scan can provide energy reinforcement to the edge portions of the (x+1)th scan region 27 that receive lower energy, which also helps improve the reliability of solar cell fabrication.

[0084] The first direction Q is the direction from the x-th scan line to the (x+1)-th scan line. The first direction Q can be perpendicular to the scanning direction P of the laser spot during laser scanning.

[0085] In some embodiments, along the first direction Q, the width of the overlapping portion of the y-th scan region 28 and the x-th scan region 26 is a first width W1, and the width of the x-th scan region 26 is a second width W2. The first width W1 and the second width W2 satisfy: 0 < W1 / W2 < 0.5.

[0086] For example, W1 / W2 can be 0.01, 0.05, 0.1, 0.15, 0.2, 0.3, 0.4, 0.45, or 0.49. Within the above range, an excessively large ratio of W1 / W2 can be avoided, thus preventing an excessively large overlap between the y-th scan region 28 and the x-th scan region 26, which would lead to excessive laser scanning of the x-th scan region 26 and wasted laser energy.

[0087] Along the first direction Q, the width of the overlapping portion of the y-th scan region 28 and the (x+1)-th scan region 27 is the third width W3, and the width of the (x+1)-th scan region 27 is the fourth width W4. The third width W3 and the fourth width W4 satisfy: 0 < W3 / W4 < 0.5.

[0088] For example, W3 / W4 can be 0.01, 0.05, 0.1, 0.15, 0.2, 0.3, 0.4, 0.45, or 0.49. Within these ranges, an excessively large ratio of W3 / W4 can be avoided, thus preventing an excessively large overlap between the y-th scan region 28 and the (x+1)-th scan region 27, which would lead to excessive laser scanning of the (x+1)-th scan region 27 and wasted laser energy.

[0089] In some embodiments, 160μm ≤ W1 ≤ 220μm. For example, the first width W1 can be 160μm, 170μm, 180μm, 190μm, 200μm, 210μm, or 220μm. Having a first width W1 within the above range avoids the problem of excessive laser scanning of the x-th scanning area 26 due to an excessively large first width W1, resulting in wasted laser energy. It also avoids the problem of an excessively small first width W1, making it difficult to provide energy reinforcement to the edge portions of the x-th laser processing during the y-th laser processing.

[0090] 100μm ≤ W2 ≤ 500μm. For example, the second width W2 can be 100μm, 200μm, 300μm, 400μm, or 500μm. When the second width W2 is within the above range, the width of the x-th scanning area 26 is larger, meaning the effective area of ​​the x-th laser processing can be larger, which is beneficial for improving the efficiency of the x-th laser processing.

[0091] 160μm ≤ W3 ≤ 220μm. For example, the third width W3 can be 160μm, 170μm, 180μm, 190μm, 200μm, 210μm, or 220μm. A third width W3 within this range avoids excessive laser scanning of the (x+1)th scanning area 27 due to an excessively large third width W3, thus preventing wasted laser energy. It also avoids a third width W3 being too small, making it difficult to provide energy reinforcement to the edge portions of the (x+1)th laser processing during the y-th laser processing.

[0092] 100μm ≤ W4 ≤ 500μm. For example, the fourth width W4 can be 100μm, 200μm, 300μm, 400μm, or 500μm. Within the above range, the width of the (x+1)th scanning area 27 is larger, meaning the effective area of ​​the (x+1)th laser processing can be larger, which is beneficial for improving the efficiency of the (x+1)th laser processing.

[0093] In some embodiments, along the first direction Q, the width of the xth scan region 26 is the same as the width of the (x+1)th scan region 27, and the width of the xth scan region 26 is the same as the width of the yth scan region 28. This configuration allows the xth laser processing, the (x+1)th laser processing, and the yth laser processing to use the same laser, which is beneficial for improving the fabrication efficiency of solar cells.

[0094] In some embodiments, the power of the y-th laser scan is less than or equal to the power of the x-th laser scan, and the power of the y-th laser scan is less than or equal to the power of the (x+1)-th laser scan.

[0095] When the power of the y-th laser scan is equal to the power of the x-th laser scan, and the power of the y-th laser scan is equal to the power of the (x+1)-th laser scan, the x-th laser treatment, the (x+1)-th laser treatment, and the y-th laser treatment can all use the same laser, which is beneficial to improving the fabrication efficiency of solar cells.

[0096] When the power of the y-th laser scan is less than the power of the x-th laser scan, and the power of the y-th laser scan is less than the power of the (x+1)-th laser scan, the power of the y-th laser scan is relatively small. This can avoid excessive power and waste of laser energy when the y-th laser scan scans the interval between the x-th scan area 26 and the (x+1)-th scan area 27.

[0097] In some embodiments, the power of the xth laser scan is 1000W~2000W, for example 1000W, 1200W, 1320W, 1400W, 1500W, 1600W, 1800W, or 2000W. The power of the xth laser scan is within the above range. A relatively high power for the xth laser scan can provide sufficient energy for the modification of the doped source layer 202, and can shorten the scanning time per unit area, thereby improving the fabrication efficiency of the solar cell.

[0098] The power of the (x+1)th laser scan is 1000W~2000W, for example 1000W, 1200W, 1320W, 1400W, 1500W, 1600W, 1800W, or 2000W. The power of the (x+1)th laser scan is within this range. The relatively high power of the (x+1)th laser scan provides sufficient energy for modifying the 202 doped source layer and can shorten the scanning time per unit area, thereby improving the fabrication efficiency of solar cells.

[0099] The power of the y-th laser scan is between 1000W and 2000W, for example, 1000W, 1200W, 1320W, 1400W, 1500W, 1600W, 1800W, or 2000W. The power of the y-th laser scan falls within this range. The relatively high power of the y-th laser scan provides sufficient energy for modifying the 202 doped source layer and can shorten the scanning time per unit area, thereby improving the fabrication efficiency of solar cells.

[0100] Figure 13 This is a schematic diagram of a scanning line for laser scanning of the doped source layer corresponding to the first region in the method for fabricating a solar cell provided in this embodiment of the present disclosure. Figure 14 This is another schematic diagram of the scan line for laser scanning of the doped source layer corresponding to the first region in the method for fabricating a solar cell provided in this embodiment of the present disclosure.

[0101] It should be noted that solar cells can be either grid-connected or gridless. (Reference) Figure 13 When the solar cell is a grid-connected cell, a second region 240 exists between adjacent first regions 230 in the scanning direction P. This second region 240 is a region between adjacent first regions 230 in the scanning direction P that is not subjected to laser scanning. The second region 240 between adjacent first regions 230 in the scanning direction P can be the corresponding region for subsequent grid formation, and the second region 240 between adjacent first regions 230 in the first direction Q can be the corresponding region for subsequent fine grid formation. (Reference) Figure 14 When the solar cell is a gridless cell, the first region 230 extends along the scanning direction P, and the second region 240 does not exist in the scanning direction P.

[0102] refer to Figures 3 to 5 In some embodiments, the method for removing the doped source layer 202 and the doped semiconductor layer 201 corresponding to the first region 230 includes: removing the doped source layer 202 corresponding to the first region 230 using a first wet process; and removing the doped semiconductor layer 201 corresponding to the first region 230 using a second wet process.

[0103] The first wet process can be to use a first etching solution to etch and remove the doped source layer 202 corresponding to the first region 230.

[0104] When the first wet process removes the doped source layer 202 corresponding to the first region 230, the doped source layer 202 on the second region 240 has not undergone modification treatment. Therefore, the doped source layer 202 corresponding to the second region 240 hardly reacts with the first etching solution, allowing the doped source layer 202 on the second region 240 to be retained. However, the doped source layer 202 corresponding to the first region 230 has undergone modification treatment. The first etching solution reacts with the modified doped source layer 202 corresponding to the first region 230, allowing the doped source layer 202 corresponding to the first region 230 to be removed.

[0105] It is understandable that even during the first wet process, a small portion of the doped source layer 202 corresponding to the second region 240 may be removed after reacting with the first etching solution, i.e., the thickness of the doped source layer 202 corresponding to the second region 240 is reduced. However, most of the doped source layer 202 corresponding to the second region 240 will still be retained, so that the doped source layer 202 corresponding to the second region 240 after the first wet process can still serve as a protective layer for the doped semiconductor layer 201 corresponding to the second region 240 in the second wet process step.

[0106] The first etching solution can be an acidic etching solution, such as a hydrofluoric acid solution, with a concentration of 0.5% to 1.5%, for example, 0.5%, 1%, or 1.5%. The processing time of the first etching solution can be 60s to 320s, for example, 60s, 90s, 100s, 130s, 260s, or 320s.

[0107] The process temperature for the first wet process can be 20℃~30℃, for example, 20℃, 23℃, 25℃, 28℃ or 30℃.

[0108] The second wet process can be to use a second etching solution to etch and remove the doped semiconductor layer 201 corresponding to the first region 230.

[0109] During the second wet process to remove the doped semiconductor layer 201 corresponding to the first region 230, the second etching solution reacts with the doped semiconductor layer 201 corresponding to the first region 230, thereby removing the doped semiconductor layer 201. However, the second etching solution hardly reacts with the doped source layer 202 of the second region 240, allowing the doped source layer 202 of the second region 240 to act as a protective layer, protecting the doped semiconductor layer 201 of the second region 240.

[0110] The second etching solution can be an alkaline etching solution, such as a potassium hydroxide solution with a concentration of 1.6% to 1.7%. The processing time of the second etching solution can be 500s to 600s, such as 500s, 530s, 550s, 580s, or 600s.

[0111] The process temperature for the second wet process can be 75℃~85℃, for example 75℃, 79℃, 80℃, 83℃ or 85℃.

[0112] In some embodiments, when using the second etching solution to etch away the doped semiconductor layer 201 corresponding to the first region 230, a portion of the substrate 200 material corresponding to the first region 230 will also be etched away.

[0113] In some embodiments, the doped source layer 202 corresponding to the first region 230 undergoes a modification treatment including n laser scans, causing the dopants in the doped source layer 202 and the doped semiconductor layer 201 corresponding to the first region 230 to diffuse towards the substrate 200 under the action of laser scanning, thereby reducing the doping concentration of the dopants near the surface of the doped source layer 202 in the first region 230 and the doped semiconductor layer 201. The lower doping concentration of the doped source layer 202 corresponding to the first region 230 makes it easier for the first etching solution to react with it, thus removing it during the first wet process. During the second wet process, the lower doping concentration of the surface doped elements of the doped semiconductor layer 201 in the first region 230 away from the substrate 200 makes it easier for the second etching solution to react with it, thus removing the doped semiconductor layer 201 corresponding to the first region 230.

[0114] In some embodiments, the method for fabricating a solar cell further includes: performing a post-oxidation treatment to form an oxide layer (not shown) on the substrate 200 corresponding to the first region 230.

[0115] The oxide layer can be a silicon oxide layer.

[0116] The oxide layer can be used to repair laser damage on the substrate 200 corresponding to the first region 230 after laser scanning, thereby improving the performance of the finally fabricated solar cell.

[0117] The post-oxidation treatment involves providing oxygen-containing gas. This oxygen-containing gas can be oxygen, ozone, etc. The process duration of the post-oxidation treatment can be 4000s to 5000s, for example, 4000s, 4300s, 4500s, 4700s, or 5000s. The temperature of the post-oxidation treatment is 1000℃ to 1100℃, for example, 1000℃, 1030℃, 1060℃, 1080℃, or 1100℃.

[0118] refer to Figure 5 and Figure 6 In some embodiments, the method for fabricating a solar cell further includes removing the doped source layer 202 corresponding to the second region 240. This avoids negative impacts on the electrical contact between the first electrode 203 and the doped semiconductor layer 201 caused by the presence of the doped source layer 202.

[0119] In some embodiments, when removing the doped source layer 202 corresponding to the second region 240, the oxide layer corresponding to the first region 230 can also be removed simultaneously. This can improve the fabrication efficiency of the solar cell. It also prevents the oxide layer present in the first region 230 from affecting the passivation effect of the subsequently formed passivation layer on the substrate 200.

[0120] refer to Figure 6In some embodiments, the method for fabricating a solar cell further includes forming a first passivation layer 204, which is located on a first side 210. Specifically, the first passivation layer 204 is located on a substrate 200 corresponding to a first region 230 of the first side 210, and also on the surface of the doped semiconductor layer 201 facing away from the second side 220.

[0121] The first passivation layer 204 is used to saturate defects in the substrate 200 and reduce the interface state density.

[0122] The material of the first passivation layer 204 can be at least one of silicon oxide, aluminum oxide, silicon nitride, or silicon oxynitride.

[0123] The first passivation layer 204 can be a single-layer structure or a multi-layer structure. For a multi-layer structure, the materials of different layers can be different from each other, or some layers can be made of the same material but different from the materials of other layers. For example, the first passivation layer 204 can be a multi-layer structure of silicon nitride and aluminum oxide layers.

[0124] Continue to refer to Figure 6 In some embodiments, the method for fabricating a solar cell further includes: forming a first electrode 203, wherein the first electrode 203 is in electrical contact with a doped semiconductor layer 201.

[0125] The material of the first electrode 203 can be copper, silver, nickel or aluminum.

[0126] In some embodiments, before forming the first electrode 203, the method for fabricating a solar cell further includes: forming a tunneling layer (not shown) located on the second side 220; forming a doped conductive layer (not shown) located on the side of the tunneling layer facing away from the substrate 200; and forming a second passivation layer (not shown) located on the surface of the doped conductive layer facing away from the substrate 200.

[0127] The tunneling layer is used to form a dense interface with the substrate 200, reducing dangling bonds in the substrate 200 and lowering the interfacial recombination rate. It also allows majority carriers in the substrate 200 (such as electrons in the N-type substrate 200) to pass through efficiently via the "tunneling effect," while blocking minority carriers in the substrate 200 (such as holes in the N-type substrate 200) from passing through, thus reducing recombination.

[0128] The material of the tunneling layer may include at least one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, or magnesium fluoride.

[0129] The conductivity type of the doped elements in the doped conductive layer is different from that of the doped elements in the doped semiconductor layer 201.

[0130] The material of the doped conductive layer can be at least one of amorphous silicon, polycrystalline silicon, or silicon carbide.

[0131] The second passivation layer is used to saturate the substrate 200 defects, reduce the interface state density, and also protect the doped conductive layer from external environmental erosion.

[0132] In some embodiments, the method for fabricating a solar cell may further include: forming a second electrode (not shown), wherein the second electrode is in electrical contact with a doped conductive layer.

[0133] The material of the second electrode can be copper, silver, nickel, or aluminum.

[0134] Accordingly, this disclosure also provides a solar cell prepared by the method for preparing solar cells according to any of the above embodiments. It should be noted that the parts that are the same as or corresponding to those in the foregoing embodiments can be referred to the corresponding descriptions in the foregoing embodiments, and will not be repeated hereafter.

[0135] Continue to refer to Figure 6 The solar cell includes: a substrate 200, a doped semiconductor layer 201 and a first electrode 203. The substrate 200 has a first side 210 and a second side 220 opposite to each other. The substrate 200 includes a first region 230 and a second region 240 that are separate from each other. The second region 240 of the first side 210 has the doped semiconductor layer 201. The first electrode 203 is in electrical contact with the doped semiconductor layer 201.

[0136] In the solar cell provided in this embodiment, a doped semiconductor layer 201 is provided only in the second region 240 of the first side 210, while no doped semiconductor layer 201 is provided in the second region 240 of the first side 210. This can reduce parasitic absorption caused by the doped semiconductor layer 201, thereby improving the performance of the solar cell.

[0137] Accordingly, this disclosure provides some embodiments, and in another aspect, a photovoltaic module. The photovoltaic module comprises multiple solar cells prepared by the method described in any of the above embodiments, connected together, or is composed of multiple solar cells connected together as described in the above embodiments. It should be noted that the parts that are the same as or corresponding to the foregoing embodiments can be referred to the corresponding descriptions in the foregoing embodiments, and will not be repeated below.

[0138] Figure 15 This is a partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in an embodiment of this disclosure; Figure 16 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in an embodiment of this disclosure.

[0139] refer to Figure 15 and Figure 16The photovoltaic module includes: a cell string, an encapsulating film 301, and a cover plate 302. The cell string is formed by connecting multiple solar cells 300 prepared by the method of any of the above embodiments, or by connecting multiple solar cells 300 as described in the above embodiments; the encapsulating film 301 is used to cover the surface of the cell string; the cover plate 302 is used to cover the surface of the encapsulating film 301 facing away from the cell string.

[0140] In some embodiments, the solar cell 300 is electrically connected in the form of a single sheet or multiple segments to form multiple cell strings, and the multiple cell strings are electrically connected in series and / or parallel. The solar cell 300 can be a single cell or a sliced ​​cell, where a sliced ​​cell refers to a cell formed by cutting a single, complete cell.

[0141] Multiple solar cells 300 can be electrically connected via solder strip 303.

[0142] In some embodiments, the encapsulating film 301 includes a first encapsulating layer and a second encapsulating layer. The first encapsulating layer covers one of the first and second surfaces of the solar cell 300, and the second encapsulating layer covers the other of the first and second surfaces of the solar cell 300. Specifically, at least one of the first or second encapsulating layer may be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyethylene terephthalate (PET) film; or, at least one of the first or second encapsulating layer may also be an EP film, EPE film, or PVP film. Among them, EP film refers to a co-extruded film composed of stacked EVA film and POE film; EPE film refers to a co-extruded film formed by sequentially stacking EVA film, POE film, and EVA film; and PVP film refers to a co-extruded film formed by stacking POE film, EVA film, and POE film. Co-extruded films can be prepared by sequentially extruding one or more raw materials onto another pre-made film during the film processing, or by bonding different types of pre-made films together.

[0143] In some cases, the first encapsulation layer and the second encapsulation layer still have a boundary line before lamination. After lamination, the photovoltaic module will no longer have the concept of a first encapsulation layer and a second encapsulation layer. That is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 301.

[0144] In some embodiments, the cover plate 302 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 302 facing the encapsulating film 301 can be an uneven surface or a textured surface containing multiple raised structures, thereby increasing the utilization rate of incident light. The cover plate 302 includes a first cover plate and a second cover plate, the first cover plate being opposite to the first encapsulation layer, and the second cover plate being opposite to the second encapsulation layer.

[0145] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of this disclosure. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this disclosure; therefore, the scope of protection of this disclosure should be determined by the scope defined in the claims.

Claims

1. A method for preparing a solar cell, characterized in that, include: A substrate is provided having a first side and a second side opposite to each other. The substrate includes a first region and a second region that are separate from each other. The first side has a doped semiconductor layer and a doped source layer, the doped source layer being located on a surface of the doped semiconductor layer opposite to the second side. The first region is subjected to n laser scans, wherein the n laser scans satisfy the following: The xth laser scan corresponds to scanning along the xth scan line, the (x+1)th laser scan corresponds to scanning along the (x+1)th scan line, and the yth laser scan corresponds to scanning along the yth scan line. The yth scan line is located between the xth scan line and the (x+1)th scan line, 1 ≤ x < n, y is different from x and different from x+1, and x, y and n are all arbitrary positive integers. Remove the doped source layer and the doped semiconductor layer corresponding to the first region.

2. The method for preparing a solar cell according to claim 1, characterized in that, The third scan line is located between the first and second scan lines.

3. The method for preparing a solar cell according to claim 2, characterized in that, The fourth scan line is located on the side of the second scan line that is opposite to the third scan line.

4. The method for preparing a solar cell according to claim 1, characterized in that, The third scan line is located on the side of the first scan line away from the second scan line, or the third scan line is located on the side of the second scan line away from the first scan line.

5. The method for preparing a solar cell according to claim 4, characterized in that, The third scan line is located on the side of the first scan line away from the second scan line, and the fourth scan line is located between the first scan line and the second scan line; or, The third scan line is located on the side of the second scan line away from the first scan line, the fourth scan line is located between the first scan line and the second scan line, and the fifth scan line is located between the second scan line and the third scan line.

6. The method for preparing a solar cell according to claim 1, characterized in that, The x-th scan area and the (x+1)-th scan area are separated, wherein the x-th scan area is the area of ​​the x-th laser scan, and the (x+1)-th scan area is the area of ​​the (x+1)-th laser scan.

7. The method for preparing a solar cell according to claim 6, characterized in that, The area of ​​the y-th laser scan is the y-th scan area, which is located in the interval between the x-th scan area and the x+1-th scan area, and the area of ​​the y-th scan area accounts for 80% to 100% of the area of ​​the interval.

8. The method for preparing a solar cell according to claim 6, characterized in that, Along the first direction, the distance between the xth scan region and the (x+1)th scan region is greater than 0 and less than or equal to 520 μm.

9. The method for preparing a solar cell according to any one of claims 1 to 8, characterized in that, The area of ​​the yth laser scan is the yth scan area, the area of ​​the xth laser scan is the xth scan area, and the area of ​​the (x+1)th laser scan is the (x+1)th scan area. The yth scan area partially overlaps with the xth scan area and also partially overlaps with the (x+1)th scan area.

10. The method for preparing a solar cell according to claim 9, characterized in that, Along the first direction, the width of the overlapping portion of the y-th scan region and the x-th scan region is the first width W1, and the width of the x-th scan region is the second width W2. The first width W1 and the second width W2 satisfy: 0 < W1 / W2 < 0.

5.

11. The method for preparing a solar cell according to claim 10, characterized in that, 160μm≤W1≤220μm; 100μm≤W2≤500μm.

12. The method for preparing a solar cell according to claim 9, characterized in that, Along the first direction, the width of the overlapping portion of the y-th scan region and the (x+1)-th scan region is the third width W3, and the width of the (x+1)-th scan region is the fourth width W4. The third width W3 and the fourth width W4 satisfy: 0 < W3 / W4 < 0.

5.

13. The method for preparing a solar cell according to claim 12, characterized in that, 160μm≤W3≤220μm; 100μm≤W4≤500μm.

14. The method for preparing a solar cell according to claim 1, characterized in that, The power of the y-th laser scan is less than or equal to the power of the x-th laser scan, and the power of the y-th laser scan is less than or equal to the power of the (x+1)-th laser scan.

15. The method for preparing a solar cell according to claim 1, characterized in that, The power of the xth laser scan is 1000W~2000W, the power of the (x+1)th laser scan is 1000W~2000W, and the power of the yth laser scan is 1000W~2000W.

16. The method for preparing a solar cell according to claim 1, characterized in that, The method for removing the doped source layer and the doped semiconductor layer corresponding to the first region includes: removing the doped source layer corresponding to the first region using a first wet process; and removing the doped semiconductor layer corresponding to the first region using a second wet process.

17. A solar cell, characterized in that, The solar cell is prepared by the method for preparing a solar cell according to any one of claims 1 to 16, and the solar cell comprises: A substrate having opposing first and second sides, the substrate comprising a first region and a second region separate from each other, the second region on the first side having a doped semiconductor layer.

18. A photovoltaic module, characterized in that, include: A battery string is formed by connecting multiple solar cells prepared by the method of any one of claims 1 to 16, or by connecting multiple solar cells as described in claim 17; An encapsulating film is used to cover the surface of the battery string; A cover plate is used to cover the surface of the encapsulating film that faces away from the battery string.

Images