Manufacturing method of solar cell, solar cell and photovoltaic module

Abstract

The embodiment of the invention relates to the photovoltaic field, and provides a manufacturing method of a solar cell piece, the solar cell piece and a photovoltaic module, and the manufacturing method of the solar cell piece comprises the steps: providing a first cell piece which comprises a substrate, the back surface of which is provided with first doped conductive layers and second doped conductive layers which are alternately arranged, a gap is formed between the first doped conductive layer and the second doped conductive layer; the passivation layer is located on the surface of the first doped conductive layer, the surface of the second doped conductive layer and the interval; photoluminescence imaging processing is conducted on the first battery piece, imaging brightness values corresponding to the passivation layers on the intervals are obtained, an analysis result is obtained based on the relation between the imaging brightness values and a target brightness value, and the analysis result is used for representing whether the passivation effect of the first battery piece is qualified or not; forming a first electrode and a second electrode on the first battery piece with the qualified passivation effect; and the passivation effect at the position corresponding to the interval can be tested.

Description

Technical Field

[0001] The present disclosure relates to the field of photovoltaics, and particularly to a method for manufacturing a solar cell, a solar cell, and a photovoltaic module. Background Art

[0002] At present, with the gradual depletion of fossil energy, solar cells, as a new energy alternative, are being used more and more widely. A solar cell is a device that converts the light energy of the sun into electrical energy. The solar cell utilizes the photovoltaic effect to generate carriers, and then uses electrodes to extract the carriers, so as to facilitate the effective utilization of electrical energy.

[0003] A BC cell (Back Contact) is a back-junction back-contact solar cell structure in which positive and negative metal electrodes are arranged in an interdigitated manner on the backlight side of the cell, and its p-n junction is located on the back of the cell. Among them, the back-junction means that the p-n junction is located on the back of the cell.

[0004] Currently, it is difficult to judge the passivation effect of the surface passivation layer spaced between different doping layers on the back of the BC cell. Summary of the Invention

[0005] Embodiments of the present disclosure provide a method for manufacturing a solar cell, a solar cell, and a photovoltaic module, which can at least obtain the passivation effect of the passivation layer at the position of the interval during the manufacturing process.

[0006] According to some embodiments of the present disclosure, on the one hand, an embodiment of the present disclosure provides a method for manufacturing a solar cell, including: providing a first cell, the first cell including: a substrate, the substrate including opposite front and back surfaces, the back surface having alternately arranged first doped conductive layers and second doped conductive layers, and there being an interval between the first doped conductive layer and the second doped conductive layer; a passivation layer, the passivation layer being located on the surface of the first doped conductive layer, the surface of the second doped conductive layer, and the interval; performing photoluminescence imaging processing on the first cell to obtain an imaging brightness value corresponding to the passivation layer on the interval, and obtaining an analysis result based on the relationship between the imaging brightness value and a target brightness value, the analysis result being used to characterize whether the passivation effect of the first cell is qualified; forming a first electrode and a second electrode on the first cell with a qualified passivation effect, the first electrode being electrically connected to the first doped conductive layer, and the second electrode being electrically connected to the second doped conductive layer.

[0007] In some embodiments, obtaining whether the passivation effect of the first cell is qualified based on the relationship between the imaging brightness value and the target brightness value includes: obtaining the average brightness value of the imaging brightness values of n of the intervals, where 1 < n ≤ N, N is the number of intervals of the first cell, and both n and N are positive integers; obtaining the difference ratio between the difference between the average brightness value and the target brightness value and the target brightness value. If the difference ratio is less than or equal to a preset ratio, the passivation effect of the first cell is qualified. If the difference ratio is greater than the preset ratio, the passivation effect of the first cell is unqualified.

[0008] In some embodiments, if the number of intervals of the first cell is less than 10, the value of n / N is greater than 50%; if the number of intervals of the first cell is greater than 10, and the value of n / N is 10% - 50%, and the larger the value of N, the smaller the value of n / N.

[0009] In some embodiments, during the process of obtaining the imaging brightness value, obtain the imaging brightness value of the passivation layer on some of the intervals, and the intervals for obtaining the imaging brightness value are separated by at least one interval.

[0010] In some embodiments, obtaining the average brightness value of the imaging brightness values of n of the intervals includes: obtaining the average brightness value of the imaging brightness values of the entire passivation layer including the passivation layer on the surface of the interval and the passivation layer between the passivation layers on the surface of the interval.

[0011] In some embodiments, after obtaining whether the passivation effect of the first cell is qualified based on the relationship between the imaging brightness value and the target brightness value, it further includes: obtaining the difference between the imaging brightness values corresponding to the passivation layers on different intervals, and correcting the analysis result based on the relationship between the difference and a preset difference to obtain a corrected result; where if the difference is less than or equal to the preset difference, the corrected result indicates that the passivation effect of the first cell is qualified, and if the difference is greater than the preset difference, it indicates that the passivation effect of the first cell is unqualified.

[0012] In some embodiments, the method for obtaining the target brightness value includes: forming a control group of cell wafers, the control group of cell wafers including: a control substrate, and a first control doping layer, a second control doping layer, a control spacer located on the surface of the control substrate, and a control passivation layer located at least on the surface of the control spacer, the process parameters for forming the first control doping layer being the same as those for forming the first doped conductive layer, the process parameters for forming the second control doping layer being the same as those for forming the second doped conductive layer, and the process parameters for forming the control passivation layer being the same as those for forming the passivation layer; performing photoluminescence imaging processing, obtaining the brightness value of the control passivation layer located in the control spacer after imaging, and using this brightness value as the target brightness value.

[0013] In some embodiments, the method for obtaining the target brightness value includes: before forming the first doped conductive layer and the second doped conductive layer of the first cell wafer, forming m first initial doped conductive layers, m second initial doped conductive layers, m initial spacers, and an initial passivation layer located on the surface of the initial spacers, where m is a positive integer greater than or equal to 1 and less than the number of the first doped conductive layers of the first cell wafer; performing initial photoluminescence imaging processing, obtaining the initial imaging brightness value corresponding to the initial passivation layer on the surface of the initial spacers, and the initial imaging brightness value being the target brightness value; forming the first doped conductive layer, the second doped conductive layer, and the spacer on the basis of the first initial doped conductive layer, the second initial doped conductive layer, and the initial spacer.

[0014] In some embodiments, the formed first initial doped conductive layer and second initial doped conductive layer cover a part of the substrate, and the method for forming the first doped conductive layer, the second doped conductive layer, and the spacer includes: forming a protective layer that covers the surface of the initial passivation layer; forming a third initial doped conductive layer, a fourth initial doped conductive layer, and a second initial passivation layer on the back surface where the first initial doped conductive layer and the second initial doped conductive layer are not formed, the third initial doped conductive layer and the first initial doped conductive layer constituting the first doped conductive layer, the second initial doped conductive layer and the fourth initial doped conductive layer constituting the second doped conductive layer, and the initial passivation layer and the second initial passivation layer constituting the passivation layer; removing the protective layer.

[0015] In some embodiments, the formed first initial doped conductive layer and the second initial doped conductive layer cover the entire back surface. The method for forming the first doped conductive layer, the second doped conductive layer, and the spacer includes: removing a part of the first initial doped conductive layer and forming a fifth initial doped conductive layer; removing a part of the second initial doped conductive layer and forming a sixth initial doped conductive layer. The remaining first initial doped conductive layer and the sixth initial doped conductive layer constitute the first doped conductive layer, and the remaining second initial doped conductive layer and the fifth initial doped conductive layer constitute the second doped conductive layer.

[0016] In some embodiments, the process parameters of the photoluminescence imaging process include: an exposure time of 0.1 s to 0.5 s, a luminescence intensity of 0.5 cd to 1 cd, and a wavelength of 920 nm.

[0017] In some embodiments, during the process of forming the first doped conductive layer and the second doped conductive layer, it further includes: controlling the ratio of the area of the positive projection of the first doped conductive layer on the surface of the substrate to be the same as the ratio of the area of the positive projection of the second doped conductive layer on the surface of the substrate.

[0018] According to some embodiments of the present disclosure, on the other hand, the present disclosure also provides a solar cell, which is formed by using the manufacturing method of the solar cell as described above.

[0019] According to some embodiments of the present disclosure, on yet another aspect, the present disclosure also provides a photovoltaic module, including: a battery string, the battery string includes: a plurality of solar cells formed by using the manufacturing method of the solar cell as described above, or includes the solar cell as described above; a welding strip, the welding strip is electrically connected to at least two solar cells to serially connect adjacent solar cells; an encapsulation film, the encapsulation film is used to cover the surface of the battery string; a cover plate, the cover plate is used to cover the surface of the encapsulation film away from the battery string.

[0020] The technical solution provided by the embodiments of the present disclosure has at least the following advantages: During the process of forming a solar cell, after forming a passivation layer, a photoluminescence imaging process is performed. By obtaining the imaging brightness value of the passivation layer, the passivation effect of the first solar cell is judged. For the testing process, the solution of using the photoluminescence imaging process to obtain an imaging diagram is convenient and has a low cost, which can meet the manufacturing requirements of solar cells. At the same time, the test results can also preferably reflect the passivation effect at the spacer position, so as to quickly judge whether the passivation effect of the first solar cell is qualified, and the convenience and accuracy of selecting the first solar cell can be improved. Description of the Drawings

[0021] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplary illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the figures in the drawings do not constitute a scale limitation. To more clearly illustrate the technical solutions in the embodiments of the present disclosure or in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 It is a flowchart of a manufacturing method of a solar cell provided by an embodiment of the present disclosure; Figures 2 to 4 It is a schematic structural diagram corresponding to each step of a manufacturing method of a solar cell provided by an embodiment of the present disclosure; Figure 5 It is a schematic structural diagram of a control cell provided by an embodiment of the present disclosure; Figure 6 It is an imaging schematic diagram obtained by performing photoluminescence imaging processing on a control cell provided by an embodiment of the present disclosure; Figures 7 to 9 It is a schematic structural diagram corresponding to each step of a manufacturing method of a solar cell provided by another embodiment of the present disclosure; Figures 10 to 12 It is a schematic structural diagram corresponding to each step of a manufacturing method of a solar cell provided by still another embodiment of the present disclosure; Figure 13 It is a partial three-dimensional schematic diagram of a photovoltaic module provided by an embodiment of the present disclosure; Figure 14 It is a partial cross-sectional schematic diagram of a photovoltaic module provided by an embodiment of the present disclosure.

[0023] Explanation of reference numerals: 100, first cell; 110, substrate; 120, front side; 130, back side; 140, first doped conductive layer; 150, second doped conductive layer; 160, passivation layer; 170, tunneling layer; 180, spacer; 101, first electrode; 102, second electrode; 103, control group cell; 113, control substrate; 143, first control doped layer; 153, second control doped layer; 163, control passivation layer; 183, control spacer.

[0024] 200, First solar cell; 210, Substrate; 220, Front side; 230, Back side; 240, First doped conductive layer; 250, Second doped conductive layer; 260, Passivation layer; 270, Tunneling layer; 204, First initial doped conductive layer; 205, Second initial doped conductive layer; 207, Initial spacing; 206, Initial passivation layer; 280, Spacing; 208, Protection layer; 214, Third initial doped conductive layer; 215, Fourth initial doped conductive layer; 216, Second initial passivation layer.

[0025] 300, First solar cell; 310, Substrate; 320, Front side; 330, Back side; 304, First initial doped conductive layer; 305, Second initial doped conductive layer; 340, First doped conductive layer; 350, Second doped conductive layer; 360, Passivation layer; 370, Tunneling layer; 380, Spacing; 315, Fifth initial doped conductive layer; 316, Sixth initial doped conductive layer; 306, Initial passivation layer; 307, Initial spacing.

[0026] 40, Solar cell; 41, Encapsulant film; 42, Cover plate; 43, Welding ribbon. Detailed implementation manners

[0027] Currently, during the process of forming a back-contact battery, a spacing is usually provided between the first doped conductive layer and the second doped conductive layer. As the number of spacings increases, the difficulty of passivating the spacing positions becomes greater and greater. Therefore, accurately characterizing the passivation effect in this region is very important for improving the conversion efficiency of solar cells. However, it is difficult to test the passivation effect at the spacing positions, and it does not meet the production requirements of solar cells.

[0028] The embodiments of the present disclosure provide a method for manufacturing a solar cell. During the process of forming a solar cell, after forming the passivation layer, photoluminescence imaging processing is performed, and the passivation effect of the first solar cell is judged by obtaining the imaging brightness value of the passivation layer. For the testing process, the scheme of obtaining an imaging diagram by using photoluminescence imaging processing is convenient and has a low cost, which can meet the production requirements of solar cells. At the same time, the test results can also preferably reflect the passivation effect at the spacing positions, so as to quickly judge whether the passivation effect of the first solar cell is qualified, and the convenience and accuracy of selecting the first solar cell can be improved.

[0029] In the description of the embodiments of the present disclosure, technical terms such as "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present disclosure, "a plurality" means more than two, unless otherwise specifically defined.

[0030] References to "embodiments" in this disclosure mean that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present disclosure. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment each time, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0031] In the description of the embodiments of the present disclosure, the term "and / or" is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can mean: the existence of A, the simultaneous existence of A and B, and the existence of B. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0032] In the description of the embodiments of the present disclosure, the term "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0033] In the description of the embodiments of the present disclosure, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of the present disclosure.

[0034] In the description of the embodiments of the present disclosure, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0035] In the accompanying drawings corresponding to the embodiments of the present disclosure, for better understanding and convenience of description, the thickness and area of the layers are enlarged. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component can be "directly" on the surface of the other component, or there can be a third component between the two components. On the contrary, when describing a component on the surface of another component or when another component is formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component being "substantially" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor on a partial edge of the entire surface.

[0036] In the description of the embodiments of the present disclosure, when a certain component "includes" another component, unless otherwise specified, other components are not excluded, and other components may further be included. In addition, when components such as layers, films, regions, or plates are referred to as being "on / at" another component, it can be "directly on" the other component (i.e., on the surface of the other component with no other components between them), or there can be another component between them. In addition, when components such as layers, films, regions, or plates are "directly located on" another component, or when layers, films, regions, or plates are located on the surface of another component, it means that there are no other components located between them.

[0037] The terms used in the description of the various embodiments herein are only for describing specific embodiments and are not intended to be limiting. As used in the description of the various embodiments and the appended claims, "the component" is also intended to include the plural form, unless the context clearly indicates otherwise. Among them, the component includes components such as layers, films, regions, or plates.

[0038] The following will elaborate on the embodiments of the present disclosure in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of the present disclosure, many technical details are presented to enable readers to better understand the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed by the present disclosure can still be implemented.

[0039] Reference Figures 1 to 6 , Figure 1 is a flowchart of a method for manufacturing a solar cell provided in an embodiment of the present disclosure; Figures 2 to 4 is a schematic structural diagram corresponding to each step of a method for manufacturing a solar cell provided in an embodiment of the present disclosure, where Figure 2 is a cross-sectional view of a first solar cell provided in an embodiment of the present disclosure; Figure 3 is an imaging schematic diagram obtained by performing photoluminescence imaging processing on the first solar cell provided in an embodiment of the present disclosure; Figure 4Schematic diagram of forming a first electrode and a second electrode on a first solar cell with qualified passivation effect provided by an embodiment of the present disclosure. Figure 5 Schematic diagram of a control solar cell provided by an embodiment of the present disclosure. Figure 6 Imaging schematic diagram obtained by performing photoluminescence imaging processing on a control solar cell provided by an embodiment of the present disclosure.

[0040] In some embodiments, the manufacturing method of a solar cell may include: S10: providing a first solar cell 100, the first solar cell 100 includes: a substrate 110, the substrate 110 includes an opposite front surface 120 and a back surface 130, the back surface 130 has alternately arranged first doped conductive layers 140 and second doped conductive layers 150, and there is a gap 180 between the first doped conductive layer 140 and the second doped conductive layer 150; a passivation layer 160, the passivation layer 160 is located on the surface of the first doped conductive layer 140, the surface of the second doped conductive layer 150, and the gap 180.

[0041] The manufacturing method of the solar cell may further include: S11: performing photoluminescence imaging processing on the first solar cell 100, obtaining an imaging brightness value corresponding to the passivation layer 160 on the gap 180, and obtaining an analysis result based on the relationship between the imaging brightness value and a target brightness value, and the analysis result is used to characterize whether the passivation effect of the first solar cell 100 is qualified.

[0042] The manufacturing method of the solar cell may further include: S12: forming a first electrode 101 and a second electrode 102 on the first solar cell 100 with qualified passivation effect, the first electrode 101 is electrically connected to the first doped conductive layer 140, and the second electrode 102 is electrically connected to the second doped conductive layer 150.

[0043] An embodiment of the present disclosure provides a manufacturing method of a solar cell. During the process of forming the solar cell, after forming the passivation layer 160, photoluminescence imaging processing is performed. By obtaining the imaging brightness value of the passivation layer 160 to judge the passivation effect of the first solar cell 100. For the testing process, the solution of obtaining an imaging diagram by photoluminescence imaging processing is convenient and has a low cost, which can meet the manufacturing requirements of the solar cell. At the same time, the test result can also better reflect the passivation effect at the position of the gap 180, so as to quickly judge whether the passivation effect of the first solar cell 100 is qualified, and can improve the convenience and accuracy of selecting the first solar cell 100.

[0044] In some embodiments, the first solar cell 100 may be an initial solar cell. During the process of providing the first solar cell 100, the first solar cells 100 may be provided in batches, and then the batch of solar cells may be subjected to photoluminescence imaging processing; in other embodiments, the process of providing the first solar cell 100 may also be to provide a single first solar cell 100.

[0045] The process of forming the first solar cell 100 may include: providing a substrate 110 and polishing the substrate 110. Through the polishing process, impurities on the surface of the substrate 110 can be removed, and the surface of the substrate 110 can be made relatively flat. Among them, the thickness of the substrate 110 may be 100 μm to 200 μm, and the resistivity may be 1 ohm-cm to 10 ohm-cm.

[0046] A first intrinsic polysilicon layer is formed on the back surface 130 of the substrate 110. The first intrinsic polysilicon layer may be formed by using the LPCVD method. The process parameters of LPCVD may include: deposition temperature 400 °C to 650 °C, time 40 min to 200 min.

[0047] The first intrinsic polysilicon layer is doped to form an initial doped conductive layer. The process parameters of the doping may include: diffusion temperature 600 °C to 950 °C, time 60 min to 180 min. During the process of forming the initial doped conductive layer, a first glass layer is also formed. The thickness of the formed first glass layer is 60 nm to 80 nm.

[0048] According to the pattern of the solar cell, a laser process is used to irradiate the first glass layer to ablate part of the first glass layer, and then texturing treatment is performed to remove the initial doped conductive layer at the position corresponding to the ablated first glass layer to form a first doped conductive layer 140. At the same time, the texturing treatment also forms a textured surface structure on the substrate 110 corresponding to the ablation position of the first glass layer. In other words, the substrate 110 includes a first region and a second region spaced 180 from each other. The laser process irradiates the first glass layer whose orthographic projection is located in the second region, and the texturing treatment removes the initial doped conductive layer whose orthographic projection is located in the second region.

[0049] Afterwards, the second doped conductive layer 150 is formed in the same manner as the above-mentioned formation of the first doped conductive layer 140. The second doped conductive layer 150 is located in the second region. The manner of forming the second doped conductive layer 150 is the same as that of forming the first doped conductive layer 140, except that the types of doping ions are different, which will not be elaborated here. There is also a space 180 between the formed second doped conductive layer 150 and the formed first doped conductive layer 140.

[0050] Finally, a passivation layer 160 is formed. The passivation layer 160 covers the surfaces of the first doped conductive layer 140, the spacer 180, and the second doped conductive layer 150. The material of the passivation layer 160 may include: amorphous silicon, silicon oxide, microcrystalline silicon, or a stack of silicon oxide and silicon carbide. Among them, the material of the passivation layer 160 may also be a hydrogenated material. The thickness of the formed passivation layer 160 may be 2 nm to 30 nm. In this way, the first solar cell 100 is formed. The formed passivation layer 160 may also cover the front surface 120 of the substrate 110.

[0051] Before forming the first doped conductive layer 140, it may also include: forming a tunneling layer 170.

[0052] In some embodiments, based on the relationship between the imaging brightness value and the target brightness value, it is determined whether the passivation effect of the first solar cell 100 is qualified, including: obtaining the average brightness value of the imaging brightness values of n spacers 180, where 1 < n ≤ N, N is the number of spacers 180 of the first solar cell 100, and both n and N are positive integers; obtaining the difference ratio between the difference between the average brightness value and the target brightness value and the target brightness value. If the difference ratio is less than or equal to a preset ratio, the passivation effect of the first solar cell 100 is qualified. If the difference ratio is greater than the preset ratio, the passivation effect of the first solar cell 100 is unqualified. By obtaining the average brightness value of the imaging brightness values of n spacers 180, the accuracy of the test process can be improved, the situation of misjudging the first solar cell 100 due to individual cases can be avoided, and the measurement error can be reduced.

[0053] For example, the target brightness value is 100, and the average brightness value of the imaging brightness values of n spacers 180 is 90. Then the corresponding difference ratio is 10%. Compare the difference ratio with the preset ratio. If the difference ratio is large, the passivation effect of the first solar cell 100 is unqualified. If the difference ratio is small, the passivation effect of the first solar cell 100 is qualified.

[0054] In some embodiments, the preset ratio may be set to 20%. That is to say, when the difference ratio between the difference between the average brightness value and the target brightness value and the target brightness value is less than 20%, it can be determined that the passivation effect of the first solar cell 100 is qualified.

[0055] It should be noted that the difference ratio here refers to the ratio of the difference between the average brightness value and the target brightness value to the target brightness value.

[0056] In some other embodiments, the preset ratio can also be adjusted according to the number of intervals 180. The smaller the number of intervals 180, the smaller the preset ratio can be; the larger the number of intervals 180, the larger the preset ratio can be. For the process, the more the number of intervals 180, the more unstable the passivation effect of the passivation layer 160. Limited by the process, it is difficult to control the passivation effect of the passivation layer 160 at the corresponding position of each interval 180. Therefore, the preset ratio can be appropriately adjusted to meet the production requirements of the solar cell wafer.

[0057] In some embodiments, if the number of intervals 180 of the first cell 100 is less than 10, the value of n / N is greater than 50%; if the number of intervals 180 of the first cell 100 is greater than 10, and the value of n / N is 10% - 50%, and the larger the value of N, the smaller the value of n / N. By differentiating the sampling based on the number of intervals 180 of the first cell 100, the number of samples can be controlled, the time required for the sampling process can be controlled, and when the number of intervals 180 in the first cell 100 is too large, the number of samples also has a certain ratio, thereby reducing the degree of sampling error and improving the reliability of the analysis result.

[0058] For the first cell 100, the number of intervals 180 within the first cell 100 provided at the same time can be the same. That is to say, at the same time, the specifications of a batch of first cells 100 provided are the same, so that frequent adjustment of the sampling number during the production process of the solar cell wafer can be avoided, and the process complexity of the solar cell wafer can be reduced.

[0059] In some embodiments, during the process of obtaining the imaging brightness value, the imaging brightness values of the passivation layer 160 on some intervals 180 are obtained, and there is at least one interval 180 between the intervals 180 for obtaining the imaging brightness value. In other words, during the process of obtaining the imaging brightness value, the selected sampling targets are not adjacent. For example, in the arrangement direction of the intervals 180, the selected sampling targets are the first interval, the third interval, the sixth interval, the ninth interval, etc. By controlling the non - adjacency of the sampling targets, the intervals 180 for obtaining the imaging brightness value can be relatively evenly arranged on the first cell 100, thereby improving the accuracy of the obtained average brightness value and the accuracy of the analysis result.

[0060] It should be noted that the above - mentioned sampling target refers to the interval 180 for which the imaging brightness value is obtained. For example, if the imaging brightness values of the first interval, the third interval, the sixth interval, and the ninth interval are obtained, then the first interval, the third interval, the sixth interval, and the ninth interval are used as the sampling targets for obtaining the average brightness value.

[0061] In some embodiments, during the process of obtaining the average luminance value, a random sampling method can also be selected. By using the random sampling method, systematic deviation can be avoided, and the distortion of the obtained average luminance value can be avoided.

[0062] In some embodiments, obtaining the average luminance value of n imaging luminance values spaced 180 apart includes: obtaining the average luminance value of the imaging luminance values of the entire passivation layer 160 including the passivation layer 160 on the surface spaced 180 apart and the passivation layer 160 between the passivation layers 160 on the surface spaced 180 apart. For the interval of 180, in the pattern formed after the photoluminescence imaging process, the pattern formed by the interval of 180 appears as a line shape, and it is difficult to obtain the imaging luminance value of the line shape. Therefore, during the process of obtaining the imaging luminance value, selecting the luminance values of the passivation layer 160 on the surface spaced 180 apart and the passivation layer 160 between the passivation layers 160 on the surface spaced 180 apart as the sampling target can reduce the difficulty of obtaining the imaging luminance value, facilitate reducing the time for obtaining the analysis result, and reduce the process duration of the manufacturing method of the solar cell wafer.

[0063] It can be understood that during the process of performing photoluminescence imaging on the first cell 100, the obtained pattern is the pattern on the entire surface of the first cell 100. When the method of obtaining the average luminance value of n imaging luminance values spaced 180 apart is to obtain the average luminance value of the imaging luminance values of the entire passivation layer 160 including the passivation layer 160 on the surface spaced 180 apart and the passivation layer 160 between the passivation layers 160 on the surface spaced 180 apart, the corresponding number of imaging luminance values of the passivation layer 160 on the surface spaced 180 apart and the entire passivation layer 160 between the passivation layers 160 on the surface spaced 180 apart can be directly selected by means of frame selection, and the average luminance value can be directly obtained, thereby further reducing the difficulty of obtaining the average luminance value.

[0064] It should be noted that the method of frame selection refers to directly selecting an area by a tool.

[0065] The passivation effect is the ability of the passivation layer 160 to reduce the recombination of carriers, and for the first doped conductive layer 140 and the second doped conductive layer 150, the passivation effect of the passivation layer 160 formed on the surface of the first doped conductive layer 140 and the second doped conductive layer 150 is relatively stable, but the passivation layer 160 formed at the corresponding position of the gap 180 is usually smaller in width, and there is usually a height difference between the first doped conductive layer 140 and the second doped conductive layer 150, which will cause the gap 180 to be stepped as a whole, further resulting in the passivation ability of the passivation layer 160 formed at the corresponding position of the gap 180 being unstable. Therefore, in the process of obtaining the analysis results, the passivation layer 160 formed at the corresponding position of the gap 180 plays a major role influencing the passivation effect. By judging the passivation effect of the passivation layer 160 formed at the corresponding position of the gap 180, the passivation effect of the first battery cell 100 can be judged.

[0066] The passivation target of the passivation layer 160 located at the gap 180 is the substrate 110 , the passivation target of the passivation layer 160 located on the surface of the first doped conductive layer 140 is the first doped conductive layer 140 and the substrate 110 , and the passivation target of the passivation layer 160 located on the surface of the second doped conductive layer 150 is the second doped conductive layer 150 and the substrate 110 .

[0067] In some embodiments, after obtaining whether the passivation effect of the first battery cell 100 is qualified based on the relationship between the imaging brightness value and the target brightness value, it also includes: obtaining the difference between the imaging brightness values ​​corresponding to the passivation layer 160 at different intervals 180, and based on the relationship between the difference and the preset difference, correcting the analysis result to obtain a corrected result; wherein, if the difference is less than or equal to the preset difference, the corrected result indicates that the passivation effect of the first battery cell 100 is qualified, and if the difference is greater than the preset difference, it indicates that the passivation effect of the first battery cell 100 is unqualified.

[0068] In other words, after determining the relationship between the image brightness value and the target brightness value, the imaging brightness values ​​of the passivation layer 160 at different intervals 180 are also compared with each other to determine the consistency of the process for forming the passivation layer 160. If the difference between the imaging brightness values ​​corresponding to the passivation layer 160 at different intervals 180 is greater than the preset difference, it indicates that in the process of forming the passivation layer 160, the difference between the passivation layers 160 formed at different positions is too large. By determining the consistency of the process for forming the passivation layer 160 while determining the passivation effect of the passivation layer 160, the reliability of the analysis result can be further improved, thereby further improving the reliability of the formed solar cell.

[0069] Combined with reference Figure 2 , Figure 3 , Figure 5 and Figure 6, in some embodiments, the method for obtaining the target brightness value includes: forming a control group of solar cells 103, where the control group of solar cells 103 includes: a control substrate 113, a first control doping layer 143, a second control doping layer 153, a control spacer 183, and at least a control passivation layer 163 located on the surface of the control spacer 183. The process parameters for forming the first control doping layer 143 are the same as those for forming the first doped conductive layer 140, the process parameters for forming the second control doping layer 153 are the same as those for forming the second doped conductive layer 150, and the process parameters for forming the control passivation layer 163 are the same as those for forming the passivation layer 160; performing photoluminescence imaging processing, obtaining the brightness value of the control passivation layer 163 located in the control spacer 183 after imaging, and using this brightness value as the target brightness value.

[0070] In other words, a control solar cell is formed using the same process, and only a first control doping layer 143, a second control doping layer 153, a control spacer 183, and at least a control passivation layer 163 located on the surface of the control spacer 183 are formed in the control solar cell. For the control solar cell, since there is only one control spacer 183, the passivation effect of the control passivation layer 163 formed in the control solar cell is the best. Thus, using the brightness value corresponding to the best passivation effect as the target brightness value can further provide feedback on the change in the passivation effect as the number of spacers 180 increases, thereby improving the reliability of the formed solar cells.

[0071] In some embodiments, the process parameters of the photoluminescence imaging processing include: an exposure time of 0.1 s to 0.5 s, a luminous intensity of 0.5 cd to 1 cd, and a wavelength of 920 nm. The process of the photoluminescence imaging processing is: irradiating the surface of the first solar cell 100 with light of a specific wavelength, where the photon energy is greater than the bandgap of the substrate 110 material, exciting valence band electrons to jump to the conduction band to generate electron-hole pairs, and then obtaining an image through a photographing device such as a camera due to the phenomenon of photon release through radiative recombination.

[0072] In some embodiments, during the process of forming the first doped conductive layer 140 and the second doped conductive layer 150, it further includes: controlling the ratio of the orthographic projection area of the first doped conductive layer 140 on the surface of the substrate 110 to be the same as the ratio of the orthographic projection area of the second doped conductive layer 150 on the surface of the substrate 110. In other words, it is to control the area of the first doped conductive layer 140 to be the same as the area of the second doped conductive layer 150. By controlling the areas of the first doped conductive layer 140 and the second doped conductive layer 150 to be the same, other factors can be reduced during the acquisition of the analysis result, thereby improving the reliability of the analysis result and further improving the reliability of the formed solar cells.

[0073] It should be noted that the ratio here refers to the ratio of the orthographic projection area to the area of the substrate surface.

[0074] In some embodiments, the lengths, widths, and thicknesses of the first doped conductive layer 140 and the second doped conductive layer 150 within the same solar cell can be controlled to be equal, so as to minimize the differences in the passivation layer 160 corresponding to different intervals 180 and reduce the interference of other factors during the measurement process, thereby improving the reliability of the analysis results and further improving the reliability of the formed solar cell.

[0075] An embodiment of the present disclosure provides a method for manufacturing a solar cell. During the process of forming the solar cell, after forming the passivation layer 160, a photoluminescence imaging process is performed. By obtaining the imaging brightness value of the passivation layer 160, the passivation effect of the first cell 100 is judged. For the testing process, the scheme of obtaining the imaging diagram by using the photoluminescence imaging process is convenient and has a low cost, which can meet the manufacturing requirements of the solar cell. At the same time, the test results can also better reflect the passivation effect at the interval 180 position, so as to quickly judge whether the passivation effect of the first cell 100 is qualified, and the convenience and accuracy of selecting the first cell 100 can be improved.

[0076] Another embodiment of the present disclosure also provides a method for manufacturing a solar cell. Different from the above embodiment, the method for obtaining the target brightness value is different. The following will describe the method for manufacturing a solar cell provided by another embodiment of the present disclosure with reference to the accompanying drawings. It should be noted that the same or corresponding parts as above can refer to the above embodiment, and will not be repeated hereinafter.

[0077] Reference Figures 7 to 9 , Figures 7 to 9 is a structural schematic diagram corresponding to each step of a method for manufacturing a solar cell provided by another embodiment of the present disclosure, wherein Figure 7 is a structural schematic diagram of forming the first initial doped conductive layer and the second initial doped conductive layer, Figure 8 is an image obtained by performing photoluminescence treatment on the formed first initial doped conductive layer and second initial doped conductive layer, Figure 9 is a structural schematic diagram of forming the first cell.

[0078] In some embodiments, the method for obtaining a target brightness value includes: before forming the first doped conductive layer 240 and the second doped conductive layer 250 of the first solar cell 200, forming m first initial doped conductive layers 204, m second initial doped conductive layers 205, m initial spacings 207, and an initial passivation layer 206 on the surface of the initial spacing 207, where m is a positive integer greater than or equal to 1 and less than the number of the first doped conductive layers 240 of the first solar cell 200; performing an initial photoluminescence imaging process to obtain an initial imaging brightness value corresponding to the initial passivation layer 206 on the surface of the initial spacing 207, and the initial imaging brightness value is the target brightness value; forming the first doped conductive layer 240, the second doped conductive layer 250, and the spacing 280 on the basis of the first initial doped conductive layer 204, the second initial doped conductive layer 205, and the initial spacing 207.

[0079] In other words, instead of setting a reference solar cell, the process of forming the first doped conductive layer 240, the second doped conductive layer 250, and the spacing 280 is divided into multiple steps. During the process of forming the first doped conductive layer 240, the second doped conductive layer 250, and the spacing 280, a small number of the first initial doped conductive layers 204, the second initial doped conductive layers 205, and the initial spacing 207 are first formed. After forming a small number of the first initial doped conductive layers 204, the second initial doped conductive layers 205, and the initial spacing 207, an initial photoluminescence imaging process is performed, and the initial imaging brightness value obtained from the initial photoluminescence imaging process is used as the target brightness value. Then, on this basis, the target number of the first doped conductive layer 240, the second doped conductive layer 250, and the spacing 280 are formed.

[0080] For example, one first initial doped conductive layer 204, one second initial doped conductive layer 205, and one initial spacing 207 can be first formed on the first solar cell 200, and then the initial imaging brightness value of the initial passivation layer 206 on the surface of the initial spacing 207 is measured. Since the number of the spacings 280 of the initially formed first initial doped conductive layer 204, second initial doped conductive layer 205, and initial spacing 207 is small, the passivation effect of the initial passivation layer 206 on the solar cell is better and can be used as the target brightness value. Then, the first initial doped conductive layer 204, the second initial doped conductive layer 205, and the initial spacing 207 are converted into the first doped conductive layer 240, the second doped conductive layer 250, and the spacing 280.

[0081] By controlling the target brightness value and the imaging brightness value to be measured on the same first solar cell 200 during the process of forming the solar cell, the reliability of the analysis result can be improved, and the change of the passivation effect with the increase in the number of the spacings 280 can also be observed, thus facilitating the analysis of the passivation effect of the solar cell.

[0082] In some embodiments, the method for forming the first initially doped conductive layer 204 and the second initially doped conductive layer 205 that cover a part of the substrate, to form the first doped conductive layer 240, the second doped conductive layer 250 and the spacer 280 includes: forming a protective layer 208 that covers the surface of the initial passivation layer 206; forming a third initially doped conductive layer 214, a fourth initially doped conductive layer 215 and a second initial passivation layer 216 on the back surface where the first initially doped conductive layer 204 and the second initially doped conductive layer 205 are not formed, the third initially doped conductive layer 214 and the first initially doped conductive layer 204 constitute the first doped conductive layer 240, the second initially doped conductive layer 205 and the fourth initially doped conductive layer 215 constitute the second doped conductive layer 250, and the initial passivation layer 206 and the second initial passivation layer 216 constitute the passivation layer; removing the protective layer 208.

[0083] In other words, during the formation of the first initially doped conductive layer 204 and the second initially doped conductive layer 205, the first initially doped conductive layer 204 and the second initially doped conductive layer 205 are formed only on a part of the top surface of the substrate. The formed first initially doped conductive layer 204 and second initially doped conductive layer 205 can directly serve as part of the first doped conductive layer 240 and the second doped conductive layer 250. Then, the third initially doped conductive layer 214 and the fourth initially doped conductive layer 215 are formed to complete the formation process of the first doped conductive layer 240 and the second doped conductive layer 250.

[0084] For example, a first initially doped conductive layer 204 having the same length, width and thickness as the first doped conductive layer 240 can be formed first, and a second initially doped conductive layer 205 having the same length, width and thickness as the second doped conductive layer 250 can be formed. Then, the third initially doped conductive layer 214 having the same length, width and thickness as the first doped conductive layer 240 is formed according to the target quantity, and the fourth initially doped conductive layer 215 having the same length, width and thickness as the second doped conductive layer 250 is formed according to the target quantity to complete the formation process of the first doped conductive layer 240 and the second doped conductive layer 250.

[0085] It should be noted that the substrate 210, the front surface 220, the back surface 230, the passivation layer 260 and the tunneling layer 270 in the embodiments of the present disclosure correspond to the substrate 110, the front surface 120, the back surface 130, the passivation layer 160 and the tunneling layer 170 in the above embodiments, and will not be elaborated here.

[0086] Another embodiment of the present disclosure further provides a method for manufacturing a solar cell. Different from the above embodiments, the methods for forming the first doped conductive layer, the second doped conductive layer, and the spacer are different. The following will describe the method for manufacturing a solar cell provided in another embodiment of the present disclosure with reference to the accompanying drawings. It should be noted that the same or corresponding parts as above can be referred to the above embodiments, and will not be repeated below.

[0087] Reference Figures 10 to 12 , Figures 10 to 12 FIG. is a schematic structural diagram corresponding to each step of a method for manufacturing a solar cell provided in another embodiment of the present disclosure. Among them, Figure 10 is a schematic structural diagram of forming a first initial doped conductive layer and a second initial doped conductive layer. Figure 11 is an image obtained by performing photoluminescence treatment on the formed first initial doped conductive layer and second initial doped conductive layer. Figure 12 is a schematic structural diagram of forming a first solar cell.

[0088] In some embodiments, the formed first initial doped conductive layer 304 and second initial doped conductive layer 305 cover the entire back surface. The method for forming the first doped conductive layer 340, the second doped conductive layer 350, and the spacer 380 includes: removing a part of the first initial doped conductive layer 304 and forming a fifth initial doped conductive layer 315; removing a part of the second initial doped conductive layer 305 and forming a sixth initial doped conductive layer 316. The remaining first initial doped conductive layer 304 and the sixth initial doped conductive layer 316 constitute the first doped conductive layer 340, and the remaining second initial doped conductive layer 305 and the fifth initial doped conductive layer 315 constitute the second doped conductive layer 350.

[0089] In other words, first form the first initial doped conductive layer 304 and the second initial doped conductive layer 305 that cover the entire back surface. Here, covering the entire back surface means that the first initial doped conductive layer 304 and the second initial doped conductive layer 305 as a whole are attached to the drawing. For example, the first initial doped conductive layer 304 covers 49% of the back surface, the second initial doped conductive layer 305 covers 49% of the back surface, and the spacer 380 covers 2% of the back surface. Then, by etching one first initial doped conductive layer 304 into multiple first initial doped conductive layers 304 spaced apart by 380, etching one second initial doped conductive layer 305 into multiple second initial doped conductive layers 305 spaced apart by 380, and forming a fifth initial doped conductive layer 315 at the position where the first initial doped conductive layer 304 is etched, and forming a sixth initial doped conductive layer 316 at the position where the second initial doped conductive layer 305 is etched, to form the first doped conductive layer 340 and the second doped conductive layer 350.

[0090] For example, taking the need to form 6 first doped conductive layers 340 and 6 second doped conductive layers 350 as an example, a first initial doped conductive layer 304 and a second initial doped conductive layer 305 can be formed first. Then, the first initial doped conductive layer 304 is etched to divide one first initial doped conductive layer 304 into 3 first initial doped conductive layers 304, and 3 fifth initial doped conductive layers 315 are formed at the position where the first initial doped conductive layer 304 is etched. The second initial doped conductive layer 305 is etched to divide one second initial doped conductive layer 305 into 3 second initial doped conductive layers 305, and 3 sixth initial doped conductive layers 316 are formed at the position where the second initial doped conductive layer 305 is etched. The 3 first initial doped conductive layers 304 and the 3 sixth initial doped conductive layers 316 constitute 6 first doped conductive layers 340, and the 3 second initial doped conductive layers 305 and the 3 fifth initial doped conductive layers 315 constitute 6 second doped conductive layers 350.

[0091] It can be understood that after forming the first initial doped conductive layer 304 and the second initial doped conductive layer 305 covering the entire back surface, an initial passivation layer 306 is also formed. The imaging brightness value of the initial passivation layer 306 at the corresponding position of the obtained initial interval 307 is obtained, and this brightness value is used as the target brightness value. Then, the first initial doped conductive layer 304 is etched, and the fifth initial doped conductive layer 315 is formed. The second initial doped conductive layer 305 is etched and the sixth initial doped conductive layer 316 is formed. Finally, the passivation layer 360 is formed, and the imaging brightness value of the passivation layer 360 at the corresponding position of the interval 380 is obtained. Finally, the imaging brightness value of the interval 380 is compared with the target brightness value to obtain the analysis result.

[0092] It should be noted that the substrate 310, the front surface 320, the back surface 330, the passivation layer 360, and the tunneling layer 370 in the embodiments of the present disclosure correspond to the substrate 110, the front surface 120, the back surface 130, the passivation layer 160, and the tunneling layer 170 in the above embodiments, and will not be elaborated here.

[0093] An embodiment of the present disclosure further provides a solar cell, which can be formed by the above method for manufacturing a solar cell. It should be noted that the same or corresponding parts as above can refer to the above embodiments and will not be elaborated below.

[0094] The solar cell can be an IBC (Interdigitated Back Contact) cell, a TBC (Tunnel Oxide Passivated Back Contact) cell, an HBC (Heterojunction Back Contact) cell, or a hybrid BC (Back Contact) cell.

[0095] An embodiment of the present disclosure further provides a photovoltaic module, which may include a plurality of solar cells formed by the manufacturing method of the solar cells in the above embodiments, or a plurality of solar cells in the above embodiments. Hereinafter, a photovoltaic module provided by an embodiment of the present disclosure will be described with reference to the accompanying drawings. It should be noted that the same or corresponding parts as above may refer to the above embodiments, and will not be repeated hereinafter.

[0096] Reference Figure 13 and Figure 14 , wherein, Figure 13 is a partial perspective view of a photovoltaic module provided by an embodiment of the present disclosure, Figure 14 is Figure 13 a partial cross-sectional view along the first cross-section direction BB1.

[0097] In some embodiments, the photovoltaic module includes: a battery string, the battery string includes: a plurality of solar cells 40 formed by the forming method of the solar cells 40 in some or all of the above embodiments, or includes the solar cells as described above; a welding strip 43, the welding strip 43 is electrically connected to at least two solar cells 40 to serially connect adjacent solar cells 40.

[0098] The photovoltaic module further includes: an encapsulation film 41, the encapsulation film 41 is used to cover the surface of the battery string.

[0099] The photovoltaic module further includes: a cover plate 42, the cover plate 42 is used to cover the surface of the encapsulation film 41 away from the battery string.

[0100] In some embodiments, the encapsulation film 41 includes a first encapsulation layer and a second encapsulation layer. The first encapsulation layer covers one of the front or back surfaces of the solar cell, and the second encapsulation layer covers the other of the front or back surfaces of the solar cell. Specifically, at least one of the first encapsulation layer or the second encapsulation layer may be an organic encapsulation film such as a polyvinyl butyral (PVB) film, an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene copolymer elastomer (POE) film, or a polyethylene terephthalate (PET) film. Alternatively, at least one of the first encapsulation layer or the second encapsulation layer may also be a film such as an EP film, an EPE film, or a PVP film. Among them, the EP film refers to a co-extruded film composed of an EVA film and a POE film stacked, the EPE film refers to a co-extruded film formed by sequentially stacking an EVA film + a POE film + an EVA film, and the PVP film refers to a co-extruded film formed by stacking a POE film + an EVA film + a POE film. The co-extruded film can be prepared by extruding one or more raw materials onto another film that has already been made in the process of film processing, or by bonding different types of films that have already been made together.

[0101] In some cases, there is a demarcation line between the first encapsulation layer and the second encapsulation layer before lamination. After the lamination process, there will no longer be the concept of the first encapsulation layer and the second encapsulation layer in the formed photovoltaic module, that is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0102] In some embodiments, the cover plate 42 may be a cover plate with a light-transmitting function such as a glass cover plate or a plastic cover plate. Specifically, the surface of the cover plate 42 facing the encapsulation film 41 may be a concave-convex surface or a suede surface including a plurality of protruding structures, so as to increase the utilization rate of incident light. The cover plate 42 includes a first cover plate and a second cover plate. The first cover plate faces the first encapsulation layer, and the second cover plate faces the second encapsulation layer.

[0103] Those of ordinary skill in the art can understand that the above embodiments are specific embodiments for implementing the present disclosure. In actual applications, various changes can be made in form and details without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present disclosure. Therefore, the protection scope of the embodiments of the present disclosure should be subject to the scope defined by the claims.

Claims

1. A method for manufacturing a solar cell, characterized in that: include: A first battery cell is provided, wherein the first battery cell comprises: a substrate, wherein the substrate comprises a front surface and a back surface opposite to each other, wherein the back surface has a first doped conductive layer and a second doped conductive layer arranged alternately, and a gap is provided between the first doped conductive layer and the second doped conductive layer; a passivation layer, the passivation layer being located on a surface of the first doped conductive layer, a surface of the second doped conductive layer and the gap; Performing photoluminescence imaging processing on the first cell to obtain an imaging brightness value corresponding to the passivation layer on the interval, and obtaining an analysis result based on a relationship between the imaging brightness value and a target brightness value, wherein the analysis result is used to indicate whether the passivation effect of the first cell is qualified; A first electrode and a second electrode are formed on the first battery cell with a qualified passivation effect, wherein the first electrode is electrically connected to the first doped conductive layer, and the second electrode is electrically connected to the second doped conductive layer.

2. The method for manufacturing a solar cell according to claim 1, characterized in that: The obtaining, based on the relationship between the imaging brightness value and the target brightness value, whether the passivation effect of the first cell is qualified includes: Obtaining an average brightness value of the imaging brightness values ​​of n of the intervals, 1<n≤N, N is the number of intervals of the first battery sheet, and n and N are both positive integers; The difference ratio between the average brightness value and the target brightness value and the target brightness value is obtained. If the difference ratio is less than or equal to the preset ratio, the passivation effect of the first battery cell is qualified. If the difference ratio is greater than the preset ratio, the passivation effect of the first battery cell is unqualified.

3. The method for manufacturing a solar cell according to claim 2, characterized in that: If the number of the intervals of the first battery sheet is less than 10, the value of n / N is greater than 50%; If the number of the intervals of the first battery sheet is greater than 10, and the value of n / N is 10%-50%, and the larger the value of N is, the smaller the value of n / N is.

4. The method for manufacturing a solar cell according to claim 2, characterized in that: In the process of acquiring the imaging brightness value, the imaging brightness value of the passivation layer on part of the intervals is acquired, and the intervals for acquiring the imaging brightness value are separated by at least one interval.

5. The method for manufacturing a solar cell according to claim 2, characterized in that: Acquiring an average brightness value of the imaging brightness values ​​of the n intervals includes: acquiring an average brightness value of the imaging brightness values ​​of the entire passivation layer including the passivation layer on the interval surface and the passivation layer between the passivation layers on the interval surface.

6. The method for manufacturing a solar cell according to any one of claims 1 to 5, characterized in that: After obtaining whether the passivation effect of the first cell is qualified based on the relationship between the imaging brightness value and the target brightness value, the method further includes: Obtaining the difference between the imaging brightness values ​​corresponding to the passivation layer at different intervals, and correcting the analysis result based on the relationship between the difference and a preset difference to obtain a correction result; If the difference is less than or equal to the preset difference, the correction result indicates that the passivation effect of the first battery cell is qualified; if the difference is greater than the preset difference, the correction result indicates that the passivation effect of the first battery cell is unqualified.

7. The method for manufacturing a solar cell according to claim 1, characterized in that: The method for obtaining the target brightness value includes: A control group of cells is formed, wherein the control group of cells comprises: a control substrate, and a first control doping layer, a second control doping layer, a control interval, and a control passivation layer at least located on the surface of the control interval, wherein the process parameters for forming the first control doping layer are the same as the process parameters for forming the first doped conductive layer, the process parameters for forming the second control doping layer are the same as the process parameters for forming the second doped conductive layer, and the process parameters for forming the control passivation layer are the same as the process parameters for forming the passivation layer; Photoluminescence imaging is performed to obtain a brightness value of the contrast passivation layer located in the contrast interval after imaging, and the brightness value is used as a target brightness value.

8. The method for manufacturing a solar cell according to claim 1, characterized in that: The method for obtaining the target brightness value includes: Before forming the first doped conductive layer and the second doped conductive layer of the first cell, m first initial doped conductive layers, m second initial doped conductive layers, m initial intervals, and an initial passivation layer located on the surface of the initial intervals are formed, where m is a positive integer greater than or equal to 1, and m is less than the number of the first doped conductive layers of the first cell; Performing initial photoluminescence imaging processing to obtain an initial imaging brightness value corresponding to the initial passivation layer on the initial interval surface, wherein the initial imaging brightness value is the target brightness value; The first doped conductive layer, the second doped conductive layer and the gap are formed on the basis of the first initial doped conductive layer, the second initial doped conductive layer and the initial gap.

9. The method for manufacturing a solar cell according to claim 8, characterized in that: The first initial doped conductive layer and the second initial doped conductive layer are formed to cover a portion of the substrate. The method for forming the first doped conductive layer, the second doped conductive layer and the gap includes: forming a protective layer, wherein the protective layer covers the surface of the initial passivation layer; forming a third initial doped conductive layer, a fourth initial doped conductive layer and a second initial passivation layer on the back surface where the first initial doped conductive layer and the second initial doped conductive layer are not formed, wherein the third initial doped conductive layer and the first initial doped conductive layer constitute the first doped conductive layer, the second initial doped conductive layer and the fourth initial doped conductive layer constitute the second doped conductive layer, and the initial passivation layer and the second initial passivation layer constitute the passivation layer; The protective layer is removed.

10. The method for manufacturing a solar cell according to claim 8, characterized in that: The first initial doped conductive layer and the second initial doped conductive layer are formed to cover the entire back surface, and the method for forming the first doped conductive layer, the second doped conductive layer and the spacer includes: removing a portion of the first initial doped conductive layer and forming a fifth initial doped conductive layer; A portion of the second initial doped conductive layer is removed, and a sixth initial doped conductive layer is formed. The remaining first initial doped conductive layer and the sixth initial doped conductive layer constitute the first doped conductive layer, and the remaining second initial doped conductive layer and the fifth initial doped conductive layer constitute the second doped conductive layer.

11. The method for manufacturing a solar cell according to any one of claims 1 to 5, characterized in that: The process parameters of the photoluminescence imaging process include: exposure time 0.1s-0.5s, luminous intensity 0.5cd-1cd, wavelength 920nm.

12. The method for manufacturing a solar cell according to any one of claims 1 to 5, characterized in that: The process of forming the first doped conductive layer and the second doped conductive layer also includes: controlling the proportion of the first doped conductive layer in the orthographic projection area of ​​the substrate surface to be the same as the proportion of the second doped conductive layer in the orthographic projection area of ​​the substrate surface.

13. A solar cell, characterized in that: The solar cell is a back contact cell, and is formed by the solar cell manufacturing method according to any one of claims 1 to 12.

14. A photovoltaic module, characterized in that: include: A battery string, the battery string comprising: a plurality of solar cells formed by the method for manufacturing a solar cell according to any one of claims 1 to 12, or a plurality of solar cells according to claim 13; a welding ribbon, the welding ribbon being electrically connected to at least two of the solar cells to connect adjacent solar cells in series; A packaging film, the packaging film is used to cover the surface of the battery string; A cover plate is used to cover the surface of the packaging film away from the battery string.

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