Solar cell, preparation method thereof and photovoltaic module

Abstract

The embodiment of the invention relates to the photovoltaic field, and provides a solar cell and a preparation method thereof, and a photovoltaic module, and the solar cell comprises fragmented cells which are formed by segmenting the same whole solar cell along a first direction, and the whole solar cell is provided with a front surface and a back surface which are oppositely arranged along a second direction, each fragmented battery is provided with a sub-front surface and a sub-back surface which are oppositely arranged along a second direction, the sub-front surfaces of at least two fragmented batteries formed based on the same whole solar battery are partial areas of the front surfaces, and the sub-back surfaces of at least two fragmented batteries formed based on the same whole solar battery are partial areas of the back surfaces; wherein the fragmented battery is provided with a cross section formed through segmentation treatment, two included angles which are complementary angles are formed between the cross section and the plane where the sub back surfaces are located, and one included angle is an acute angle; and the passivation layer is at least located on the fracture surface. The embodiment of the invention is at least beneficial to improving the photoelectric conversion efficiency of the solar cell comprising the fragmented cell.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the photovoltaic field, and in particular to a solar cell and a preparation method thereof, and a photovoltaic module. Background Art

[0002] In order to reduce the power reduction and hot spots of photovoltaic modules caused by differences in the electrical performance of the batteries, the high current of the whole solar cell can easily lead to significant resistance loss. In order to improve the problem of large power loss of the whole solar cell, half-cell, shingled and other forms of photovoltaic modules are constantly favored by terminal module manufacturers and users.

[0003] However, whether it is a half-cell module or a shingled module, laser cutting technology is required to cut the entire solar cell into half or multiple small slices. The sliced ​​cells have reduced efficiency due to mechanical damage during the slicing process and the presence of dangling bonds on the cut surface, thereby reducing the module power. Summary of the invention

[0004] The embodiments of the present disclosure provide a solar cell and a method for preparing the same, and a photovoltaic module, which are at least beneficial to improving the photoelectric conversion efficiency of a solar cell including split cells.

[0005] According to some embodiments of the present disclosure, on the one hand, the embodiments of the present disclosure provide a solar cell, including: a slice cell, at least two of the slice cells are formed by splitting the same whole solar cell along a first direction, the whole solar cell has a front side and a back side relatively arranged along a second direction, the slice cell has a sub-front side and a sub-back side relatively arranged along the second direction, the sub-front side of the at least two slice cells formed based on the same solar cell is a partial area of ​​the front side, and the sub-back side of the at least two slice cells formed based on the same solar cell is a partial area of ​​the back side; wherein the second direction is the thickness direction of the slice cell, and the first direction intersects with the second direction, the slice cell has a cross-section formed by the splitting process, and two complementary angles are formed between the cross-section and the plane where the sub-back side is located, and one of the angles is an acute angle; a passivation layer, at least located on the cross-section.

[0006] In some embodiments, a single split cell includes at least one section, and a passivation layer is located on each section.

[0007] In some embodiments, in a split battery, the area of ​​the sub-front side is larger than the area of ​​the sub-back side, a first angle is formed between at least one section and the sub-back side, and the supplementary angle of the first angle is an acute angle; and / or, in another split battery, the area of ​​the sub-front side is smaller than the area of ​​the sub-back side, a second angle is formed between at least one section and the sub-back side, and the second angle is an acute angle.

[0008] In some embodiments, the acute angle is 45° to 80°.

[0009] In some embodiments, along the third direction, the passivation layer includes at least a first passivation layer and a second passivation layer stacked together, the first passivation layer contains a silicon oxide material, the second passivation layer contains a metal oxide material, the metal element in the metal oxide material includes at least one of Al element, Ti element, Zn element, Zr element, Hf element, Mo element, W element or Ni element, and the third direction is perpendicular to the cross section.

[0010] In some embodiments, the passivation layer further includes an intermediate passivation layer, which is located between the first passivation layer and the second passivation layer, and both the intermediate passivation layer and the first passivation layer contain silicon elements, and the intermediate passivation layer and the second passivation layer contain the same metal element.

[0011] In some embodiments, the material of the intermediate passivation layer includes an oxide having silicon elements and metal elements.

[0012] In some embodiments, the orthographic projection of the split cell on the sub-back surface is in the shape of a rectangle, and some corners of the rectangle are rounded.

[0013] According to some embodiments of the present disclosure, on the other hand, the embodiments of the present disclosure further provide a method for preparing a solar cell, comprising: providing a whole solar cell; splitting the entire thickness of the whole solar cell along a first direction to form at least two slice cells, and along a second direction, the thickness of the whole solar cell is the same as the thickness of the slice cell; wherein the second direction is the thickness direction of the slice cell, and the first direction intersects with the second direction, the slice cell has a sub-front side and a sub-back side arranged relatively along the second direction, the slice cell also has a cross-section formed by the splitting process, and two complementary angles are formed between the cross-section and the plane where the sub-back side is located, and one of the angles is an acute angle; and forming a passivation layer on at least the cross-section.

[0014] According to some embodiments of the present disclosure, on the other hand, the embodiments of the present disclosure further provide a photovoltaic module, including: a cell string, formed by connecting the solar cells of any of the above items, or by connecting a plurality of solar cells formed by the above preparation methods; a packaging film, used to cover the surface of the cell string; a cover plate, used to cover the surface of the packaging film away from the cell string.

[0015] The technical solution provided by the embodiments of the present disclosure has at least the following advantages:

[0016] The designed split cell is formed by splitting the whole solar cell along the first direction, and the first direction intersects with the thickness direction of the split cell, so that the angle between the cross section formed by the splitting process and the sub-back surface of the split cell is not a right angle. In other words, the whole solar cell is beveled to form the split cell, and for the sub-front surface and sub-back surface on the split cell, the cross section on the split cell can be regarded as an inclined surface.

[0017] Based on this, compared with dividing the whole solar cell along the second direction to form the cross section of the sliced ​​cell, the atomic arrangement density on the inclined cross section designed on the sliced ​​cell in one embodiment of the present disclosure is smaller, and the covalent bond surface density is smaller, and the connection between adjacent atoms on the cross section is not firm, which is more conducive to promoting the passivation layer on the cross section to form a bond with the dangling bonds on the cross section, that is, making it easier for the passivation layer to saturate the dangling bonds on the cross section, and the passivation layer can also passivate other surface defects on the cross section, which is conducive to further improving the ability of the passivation layer to reduce the defect state density of the cross section, and is more conducive to reducing the defect state density of the cross section, so as to further reduce the recombination center of the cross section to reduce the probability of carrier recombination. In other words, designing the cross section of the sliced ​​cell to be inclined relative to its sub-back surface rather than vertical and cooperating with the passivation function of the passivation layer is conducive to further improving the passivation effect of the passivation layer on the cross section, so as to further reduce the probability of carrier recombination on the cross section, and improve the life of the carrier, thereby further improving the photoelectric conversion efficiency of the sliced ​​cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings, and these exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the traditional technology, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic cross-sectional structure diagram of a single whole solar cell divided into at least two sub-cells provided in an embodiment of the present disclosure;

[0020] Figure 2 A schematic diagram of a first partial cross-sectional structure of a solar cell provided by an embodiment of the present disclosure;

[0021] Figure 3 A schematic diagram of a top view structure in which a single whole solar cell provided in an embodiment of the present disclosure is divided into two sub-cells;

[0022] Figure 4A schematic diagram of a top view structure in which a single whole solar cell provided in an embodiment of the present disclosure is divided into four sub-cells;

[0023] Figure 5 A schematic diagram of a top view structure of a single whole solar cell divided into 9 sub-cells provided in an embodiment of the present disclosure;

[0024] Figure 6 A schematic diagram of a second partial cross-sectional structure of a solar cell provided by an embodiment of the present disclosure;

[0025] Figure 7 A schematic diagram of a third partial cross-sectional structure of a solar cell provided in one embodiment of the present disclosure;

[0026] Figure 8 A schematic diagram of a partial cross-sectional structure of a segmented cell and a passivation layer in a solar cell provided in an embodiment of the present disclosure;

[0027] Fig. 9 for Figure 8 The graph showing the percentage of element contents in the sliced ​​battery and the passivation layer;

[0028] Fig.10 A schematic diagram of a fourth partial cross-sectional structure of a solar cell provided in one embodiment of the present disclosure;

[0029] Fig.11 A fifth partial cross-sectional structural schematic diagram of a solar cell provided by an embodiment of the present disclosure;

[0030] Fig.12 A sixth partial cross-sectional structural schematic diagram of a solar cell provided in an embodiment of the present disclosure;

[0031] Fig.13 A seventh partial cross-sectional structural schematic diagram of a solar cell provided by an embodiment of the present disclosure;

[0032] Fig.14 An eighth partial cross-sectional structural schematic diagram of a solar cell provided by an embodiment of the present disclosure;

[0033] Fig.15 A schematic diagram of a partial top view structure of a solar cell provided by an embodiment of the present disclosure;

[0034] Fig.16 A schematic diagram of a partial three-dimensional structure of a photovoltaic assembly provided by another embodiment of the present disclosure;

[0035] Fig.17 for Fig.16 A schematic diagram of a cross-sectional structure along the cross-sectional direction MM1. DETAILED DESCRIPTION

[0036] As known from the background art, the photoelectric conversion efficiency of the solar cells after segmentation needs to be improved.

[0037] After analysis, it was found that in order to improve the problem of large power loss of the whole solar cell, laser cutting technology is used to cut the whole solar cell into half or multiple small pieces of sliced ​​cells, and then the sliced ​​cells are connected in series using conductive welding ribbons. The series current is lower than the whole piece current. The current reduction of the sliced ​​cells can improve the power loss of the photovoltaic module.

[0038] However, during the laser slicing process, if the laser partially melts the entire solar cell along a set path, and then mechanical force is used to crack the cell along the set path to achieve slicing, a cutting edge will be left on the sliced ​​cell, and a laser damage zone and a mechanical fracture zone will be formed on the cutting edge, resulting in the inability of the silicon atoms at the cutting edge to maintain their original ordered arrangement state, and a large number of defect states will exist on the surface, which will become effective recombination centers for carriers. A large number of carriers will recombine based on the recombination centers, seriously damaging the photoelectric conversion efficiency of the sliced ​​cell; if the entire solar cell is split along the thickness direction of the entire solar cell, the cross-section of the formed sliced ​​cell is approximately perpendicular to the front or back of the solar cell, and the atomic arrangement density and covalent bond surface density on the cross-section formed based on the splitting angle are relatively large, so that even if a passivation layer is prepared on the cross-section to passivate the defect states on the cross-section, the large covalent bond surface density will also cause resistance to the passivation layer saturating the defect states on the cross-section, hindering the further improvement of the passivation effect of the passivation layer on the cross-section.

[0039] The present disclosure provides a solar cell and a method for preparing the same, as well as a photovoltaic module. In the solar cell, the angle between the cross section formed by the splitting process on the sliced ​​cell and the sub-back surface is not a right angle, that is, the entire solar cell is beveled to form the sliced ​​cell, and for the sub-front surface and sub-back surface on the sliced ​​cell, the cross section on the sliced ​​cell can be regarded as an inclined surface. Based on this, compared with splitting the entire solar cell along the second direction to form the cross section of the sliced ​​cell, the atomic arrangement density on the inclined cross section designed on the sliced ​​cell in one embodiment of the present disclosure is smaller, and the covalent bond surface density is smaller, so the connection between adjacent atoms on the cross section is not firm, which is more conducive to promoting the passivation layer on the cross section to bond with the dangling bonds on the cross section, that is, making it easier for the passivation layer to saturate the dangling bonds on the cross section, and the passivation layer can also passivate other surface defects on the cross section, which is conducive to further improving the ability of the passivation layer to reduce the defect state density of the cross section, so as to further reduce the recombination center of the cross section to reduce the probability of carrier recombination. In other words, designing the cross-section of the segmented cell to be inclined rather than perpendicular to its sub-back surface and cooperating with the passivation function of the passivation layer can help further improve the passivation effect of the passivation layer on the cross-section, thereby further reducing the probability of carrier recombination on the cross-section and increasing the carrier lifetime, thereby further improving the photoelectric conversion efficiency of the segmented cell.

[0040] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0041] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0042] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0043] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0044] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0045] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of 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 application can be understood according to the specific circumstances.

[0046] In the accompanying drawings corresponding to the embodiments of the present application, the thickness and area of ​​the layer are magnified for better understanding and ease of description. When describing a component (such as a layer, film, region or substrate) on another component or on the surface of another component, the component can be "directly" located on the surface of the other component, or a third component can be present 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 as "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 is it formed on a partial edge of the entire surface.

[0047] In the description of the embodiments of the present application, when a component "includes" another component, unless otherwise specified, other components are not excluded, and other components may be further included. In addition, when a component such as a layer, a film, a region, or a plate is referred to as being "on / located on" another component, it may 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 exist in between. In addition, when a component such as a layer, a film, a region, a plate, etc. is "directly located on" another component, or when a component such as a layer, a film, a region, a plate, etc. is located on the surface of another component, it means that no other components are located in between.

[0048] The terms used in the description of the various embodiments described herein are only used to describe specific embodiments and are not intended to be limiting. As used in the description of the various embodiments described and in the appended claims, "the components" are also intended to include plural forms unless the context clearly indicates otherwise. Among them, components include components such as layers, films, regions, or plates.

[0049] The following will describe the various embodiments of the present disclosure in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present disclosure, many technical details are provided in order to enable the reader to better understand the embodiments of the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the embodiments of the present disclosure can be implemented.

[0050] An embodiment of the present disclosure provides a solar cell, which will be described in detail below with reference to the accompanying drawings.

[0051] refer to Figure 1 and Figure 2 , solar cells include: segmented solar The invention relates to a solar cell 110, wherein at least two of the split cells 110 are formed by splitting the same whole solar cell 100 along a first direction X, the whole solar cell 100 has a front side 100a and a back side 100b arranged relatively along a second direction Y, the split cell 110 has a sub-front side 110a and a sub-back side 110b arranged relatively along the second direction Y, the sub-front side 110a of the at least two split cells 110 formed based on the same whole solar cell 100 is a partial area of ​​the front side 100a, and the sub-back side 110b of the at least two split cells 110 formed based on the same whole solar cell 100 is a partial area of ​​the back side 100b; wherein the second direction Y is a thickness direction of the split cell 110, and the first direction X intersects with the second direction Y, the split cell 110 has a cross section 110c formed by the splitting process, and two complementary angles are formed between the cross section 110c and the plane where the sub-back side 110b is located, and one of the angles is an acute angle; and the passivation layer 101 is at least located on the cross section 110c.

[0052] in, Figure 1 A schematic cross-sectional structure diagram of a single whole solar cell divided into at least two sub-cells provided in an embodiment of the present disclosure; Figure 2 A schematic diagram of a first partial cross-sectional structure of a solar cell provided in one embodiment of the present disclosure.

[0053] In some cases, due to the segmentation process, a large number of defect states, mechanical damage caused by the segmentation process or other surface defects may exist on the cross section 110c formed by the segmentation process on the segmented battery 110. Moreover, due to the various surface defects on the cross section 110c, impurities may be easily introduced on the cross section 110c. These defects and impurities may easily serve as recombination centers for electron-hole pairs and shorten the life of carriers, resulting in a reduction in the photoelectric conversion efficiency of the segmented battery 110. It should be noted that the segmentation process includes but is not limited to laser cutting, and laser cutting may also easily leave laser damage on the cross section 110c.

[0054] It is worth noting that the sub-front side 110a of at least two split cells 110 formed based on the same whole solar cell 100 is a partial area of ​​the front side 100a, and the sub-back side 110b of at least two split cells 110 formed based on the same whole solar cell 100 is a partial area of ​​the back side 100b, then the split cell 110 is formed by cutting the whole solar cell 100 from its front side 100a to its back side 100b, or from its back side 100b to its front side 100a, so that the thickness direction of the whole solar cell 100 and the thickness direction of the split cell 110 are both the second direction Y. Moreover, the cutting direction of the whole solar cell 100 is limited, that is, the split cell 110 is formed by dividing the same whole solar cell 100 along the first direction X, and the first direction X intersects with the thickness direction of the split cell 110. In this way, the angle between the cross section 110c formed by the dividing process on the split cell 110 and the sub-back side 110b is not a right angle. In other words, the entire solar cell 100 is beveled to form the segmented cell 110 , and for the sub-front side 110 a and the sub-back side 110 b on the segmented cell 110 , the cross section on the segmented cell 110 can be regarded as an inclined surface.

[0055] Moreover, compared to splitting the entire solar cell along the thickness direction of the entire solar cell to form a cross-section of a sliced ​​cell, the atomic arrangement density on the inclined cross-section 110c designed on the sliced ​​cell 110 in one embodiment of the present disclosure is smaller, and the covalent bond surface density is smaller. The connection between adjacent atoms on the cross-section 110c is not firm, which is more conducive to promoting the passivation layer 101 located on the cross-section 110c to form a bond with the dangling bonds on the cross-section 110c, that is, making it easier for the passivation layer 101 to saturate the dangling bonds on the cross-section 110c. In addition, the passivation layer 101 can also passivate other surface defects on the cross-section 110c, which is conducive to further improving the ability of the passivation layer 101 to reduce the defect state density of the cross-section 110c, so as to further reduce the recombination center of the cross-section 110c to reduce the carrier recombination probability. In other words, designing the cross section 110c of the segmented cell 110 to be inclined rather than perpendicular to its sub-back side 110b and cooperating with the passivation function of the passivation layer 101 is beneficial to further improve the passivation effect of the passivation layer 101 on the cross section 110c, so as to further reduce the probability of carrier recombination on the cross section 110c, increase the carrier lifespan, and thus further improve the photoelectric conversion efficiency of the segmented cell.

[0056] In some cases, compared to the situation where the cross section 110c of the formed segmented cell 110 is not passivated after the entire solar cell 100 is segmented, the inclination of the cross section 110c relative to the sub-back side 110b, combined with the passivation of the cross section 110c by the passivation layer 101, is beneficial for increasing the open circuit voltage Voc of the solar cell by about 3.2 mV, the fill factor FF by about 0.80%, and the photoelectric conversion efficiency Eff by about 0.33%.

[0057] In other cases, compared to the situation where the cross section 110c of the formed slice cell 110 is passivated after the entire solar cell is split along the thickness direction of the entire solar cell to form a slice cell cross section, in a solar cell including a slice cell 110 provided by an embodiment of the present disclosure, the inclination of the cross section 110c relative to the sub-back side 110b is beneficial to increase the open circuit voltage Voc of the solar cell by about 2.5 mV, the fill factor FF by about 0.66%, and the photoelectric conversion efficiency Eff by about 0.25%.

[0058] The embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0059] In some embodiments, reference Figure 3 , Figure 4 or Figure 5 The single split cell 110 includes at least one section 110 c , and the passivation layer 101 is located on each section 110 c .

[0060] in, Figure 3A schematic diagram of a top view structure in which a single whole solar cell provided in an embodiment of the present disclosure is divided into two sub-cells; Figure 4 A schematic diagram of a top view structure in which a single whole solar cell provided in an embodiment of the present disclosure is divided into four sub-cells; Figure 5 A schematic diagram of a top view of a single whole solar cell provided in an embodiment of the present disclosure is divided into 9 sub-cells. In addition, in order to clearly illustrate the cross section 110c in each sub-cell 110, Figures 3 to 5 In the figure, a partial number of the battery slices 110 are drawn in a perspective manner.

[0061] The relationship between the sliced ​​solar cell 110 and the whole solar cell 100 is described in detail below.

[0062] In some examples, reference Figure 3 , N is 2, and a single slice cell 110 is 1 / 2 of the whole solar cell 100. In other words, the slice cell 110 is a half-cut solar cell.

[0063] In some cases, continue to refer to Figure 3 The corners of the four sides of the whole solar cell 100 that are connected in sequence are rounded corners 100c. Based on this, the corners of the sides 110d that have not been divided in the split cell 110 that are connected in sequence are still rounded corners 100c, but the corners of the section 110c connected to the side 110d in the split cell 110 do not have rounded corners.

[0064] In some cases, in conjunction with reference Figure 1 and Figure 3 , in the two sub-cells 110 belonging to the same whole solar cell 100, the angle between the cross section 110c of one sub-cell 110 and its sub-back surface 110b is a first angle β, and the angle between the cross section 110c of the other sub-cell 110 and its sub-back surface 110b is a second angle γ, and the first angle β and the second angle γ are complementary. It should be noted that, Figure 1 In the example, the first angle β is an obtuse angle and the second angle γ is an acute angle.

[0065] In other examples, reference Figure 4 , N is 4, and a single slice cell 110 is 1 / 4 of the entire solar cell 100 .

[0066] In some cases, continue to refer to Figure 4 , the segmentation path in the whole solar cell 100 is in the shape of a cross, and a rounded corner 100c is reserved at one corner of any segment cell 110. Moreover, among the four segment cells 110 belonging to the same whole solar cell 100, any segment cell 110 has two cross sections 110c.

[0067] In one example, refer to Figure 4 , of the two sections 110c of the same split battery 110, the angle between one section 110c and the sub-back surface 110b of the split battery 110 is a third angle (not shown in the figure), and the angle between the other section 110c and the split battery 110 is a fourth angle (not shown in the figure), and the third angle and the fourth angle are both acute angles; in another example, continue to refer to Figure 4 , of the two sections 110c of the same split battery 110, the angle between one section 110c and the sub-back surface 110b of the split battery 110 is a third angle (not shown in the figure), and the angle between the other section 110c and the split battery 110 is a fourth angle (not shown in the figure), and the third angle and the fourth angle are both obtuse angles; in another example, continue to refer to Figure 4 Among the two sections 110c of the same slice battery 110, the angle between one section 110c and the sub-back side 110b of the slice battery 110 is the third angle (not shown in the figure), and the angle between the other section 110c and the slice battery 110 is the fourth angle (not shown in the figure), and one of the third angle and the fourth angle is an acute angle, and the other is an obtuse angle.

[0068] It should be noted that there are multiple possibilities for the first direction X intersecting with the second direction Y. Based on different choices of the first direction X, the two sections 110c of the same split battery 110 may present different tilt states, which can be flexibly designed according to requirements in actual applications.

[0069] In other cases, the whole solar cell can also be divided into four slice cells in sequence along a fixed direction, and then only two slice cells each have two rounded corners. Among the four slice cells belonging to the same whole solar cell, the two slice cells with rounded corners each have only one cross section, and the remaining two slice cells each have two opposite cross sections along the fixed direction.

[0070] It should be noted that, based on the different ways of dividing the whole solar cell 100, among at least two slice cells 110 belonging to the same whole solar cell 100, the number of cross-sections 110c possessed by different slice cells 110 and the inclination state of each cross-section 110c may be different, and can be flexibly designed according to needs in actual applications.

[0071] In some other examples, reference Figure 5 , N is 9, and a single slice cell 110 is 1 / 9 of the entire solar cell 100.

[0072] It should be noted that the above Figures 3 to 5The three examples shown are all examples of a whole solar cell 100 being divided into at least two sub-cells 110. In practical applications, the number N of sub-cells 110 divided by a single whole solar cell 100 can be adjusted according to needs and size, for example, N can also be 3, 5, 6, 7, 8 or 10. In addition, an embodiment of the present disclosure does not limit the division path of the whole solar cell 100, which can be flexibly adjusted according to needs.

[0073] In the above various embodiments, reference Figures 1 to 5 In a partial number of split batteries 110, the area of ​​the sub-front side 110a may be larger than the area of ​​the sub-back side 110b, and a first angle β is formed between at least one section 110c and the sub-back side 110b, and the supplementary angle of the first angle β is an acute angle, that is, the first angle β formed between the section 110c and the sub-back side 110b is an obtuse angle, and an acute angle is also formed between the section 110c and the plane where the sub-back side 110b is located.

[0074] In the above various embodiments, reference Figures 1 to 5 In another part of the split battery cells 110, the area of ​​the sub-front side 110a may be smaller than the area of ​​the sub-back side 110b, and a second angle γ is formed between at least one section 110c and the sub-back side 110b, the second angle γ is an acute angle, and an obtuse angle is also formed between the section 110c and the plane where the sub-back side 110b is located.

[0075] It should be noted that, in actual applications, for a split battery with at least two cross-sections, the angles between a certain number of cross-sections and their sub-back sides are acute angles, while the angles between another number of cross-sections and their sub-back sides are obtuse angles. In this case, the area of ​​the sub-front side of the split battery may be equal to the area of ​​its sub-back side.

[0076] It is worth noting that in the above various embodiments, reference Figures 1 to 5 For any cross section 110c, the angle formed between the cross section 110c and the corresponding sub-back surface 110b is an acute angle or an obtuse angle.

[0077] In the above various embodiments, reference Figures 3 to 5 The shape of the orthographic projection of the split battery 110 on the sub-back surface 110 b may be a rectangle, and some corners of the rectangle are rounded 100 c.

[0078] In the above various embodiments, reference Figures 1 to 5, the acute angle formed between the cross section 110c and the plane where the sub-back surface 110b is located can be 45° to 80°. If the acute angle is less than 45°, the cross section 110c is too inclined relative to the sub-back surface 110b, and the portion of the slice battery 110 including the cross section 110c can be regarded as a tip protruding from the entire slice battery 110. The smaller the acute angle, the more protruding the tip, and the easier it is for the tip to break when under pressure, which is not conducive to improving the structural stability of the slice battery 110; if the acute angle is greater than 80°, the cross section 110c is too inclined relative to the sub-back surface 110b, which is not conducive to reducing the atomic arrangement density on the cross section 110c, and thus is not conducive to improving the passivation effect of the passivation layer 101 on the cross section 110c. Therefore, the acute angle is designed to be 45° to 80°, and the inclination of the cross section 110c relative to the sub-back side 110b is controlled, which is beneficial to improving the structural stability of the slice battery 110 and reducing the probability of damage to the slice battery 110, while effectively reducing the atomic arrangement density on the cross section 110c, thereby enhancing the passivation effect of the passivation layer 101 on the cross section 110c.

[0079] In some examples, the acute angle formed between the cross section 110c and the plane where the sub-back side 110b is located can be 45° to 50°, for example, the acute angle can be 46°, 47°, 48° or 49°, which is conducive to making the cross section 110c approach the fcc (111) crystal plane of the sliced ​​battery 110. It is worth noting that compared with other crystal planes, the atomic arrangement density of the fcc (111) crystal plane is the smallest, and the covalent bond surface density is the smallest, and the connection between adjacent atoms is not firm. Based on this, the acute angle formed between the plane where the cross section 110c and the sub-back side 110b are located is designed to be 45°~50°, which is beneficial to reduce the atomic arrangement density on the cross section 110c as much as possible, and enhance the ability of the passivation layer 101 to saturate the dangling bonds on the cross section 110c as much as possible, which is beneficial to further enhance the passivation effect of the passivation layer 101 on the cross section 110c, so as to further reduce the probability of carrier recombination on the cross section 110c, and increase the carrier lifetime, thereby further improving the photoelectric conversion efficiency of the sliced ​​battery.

[0080] In other examples, the acute angle formed between the cross section 110c and the plane where the sub-back surface 110b is located may also be 55°, 60°, 65°, 70°, 75°, 80° or 85°, etc.

[0081] In some embodiments, reference Figure 6 , Figure 6A schematic diagram of a second partial cross-sectional structure of a solar cell provided in an embodiment of the present disclosure, wherein along a third direction Z, the passivation layer 101 includes at least a first passivation layer 111 and a second passivation layer 121 which are stacked, the first passivation layer 111 includes a silicon oxide material, the second passivation layer 121 includes a metal oxide material, the metal element in the metal oxide material includes at least one of Al element, Ti element, Zn element, Zr element, Hf element, Mo element, W element or Ni element, and the third direction Z is perpendicular to the cross section 110c.

[0082] Thus, on the one hand, the first passivation layer 111 is designed to include a silicon oxide material, and the cross section 110c is chemically passivated by the silicon oxide material. For example, the oxygen atoms in the first passivation layer 111 saturate the dangling bonds on the cross section 110c, and the cross section 110c tilted relative to the sub-back surface 110b is used to enhance the ability of the oxygen atoms to saturate the dangling bonds on the cross section 110c, so as to further reduce the defect state density of the cross section 110c, so as to further reduce the recombination center of the cross section 110c and reduce the probability of carrier recombination; on the other hand, the second passivation layer 121 is designed to include a metal oxide material, and the metal elements in the metal oxide material include Al, T At least one of the i element, Zn element, Zr element, Hf element, Mo element, W element or Ni element, with the help of the metal element in the second passivation layer 121, the second passivation layer 121 itself has a high density of fixed charges, and the high density of fixed charges can generate a large electric field, thereby performing good field effect passivation on the section 110c, for example, a large energy band bending is generated between the second passivation layer 121 and the section 110c, hindering the minority carriers from migrating to the section 110c, reducing the concentration of minority carriers at the section 110c, thereby helping to reduce the probability of recombination of majority carriers and minority carriers at the section 110c. In this way, the first passivation layer 111 and the second passivation layer 121 cooperate together, and cooperate with the section 110c inclined relative to the sub-back surface 110b, which is conducive to significantly improving the photoelectric conversion efficiency of the sliced ​​cell 110, thereby improving the photoelectric conversion efficiency of the solar cell.

[0083] In addition, since the density of silicon oxide material is high, it is beneficial to improve the density of the first passivation layer 111, so that the film stability of the first passivation layer 111 is high, which is beneficial to protect the section 110c covered by the first passivation layer 111 through the first passivation layer 111, for example, it can prevent external impurities from invading the section 110c.

[0084] Moreover, the silicon oxide material also has a good anti-PID (potential induced degradation) effect. Since the subsequent packaging materials of the photovoltaic modules formed based on solar cells are difficult to achieve 100% isolation from the outside world, water vapor may enter the interior of the solar cell through the packaging materials or backplane used for edge sealing in a humid environment. At this time, the glass in the packaging material will produce sodium ions, and the sodium ions will move to the surface of the solar cell under the action of the external electric field to produce PID phenomenon, resulting in a decrease in the photoelectric conversion efficiency of the solar cell. The silicon oxide material has good compactness and insulation, so it has a good effect on preventing water vapor from entering the section 110c to enter the sliced ​​cell 110, thereby having a good anti-PID effect. In this way, even if the packaging material of the photovoltaic module is difficult to achieve complete insulation, water vapor enters the environment of the solar cell through the packaging material used for edge sealing, and the film layer composed of the silicon oxide material can also prevent the sodium ions in the glass in the packaging material from moving to the section 110c, thereby preventing the PID phenomenon and maintaining a high photoelectric conversion rate of the solar cell.

[0085] In some cases, along a direction perpendicular to the first direction X, i.e., direction Z, the first passivation layer 111 and the second passivation layer 121 are stacked on the cross section 110c. Compared with the second passivation layer 121, the first passivation layer 111 is closer to the cross section 110c. For example, the first passivation layer 111 can cover the cross section 110c. This helps shorten the migration path of oxygen atoms in the first passivation layer 111 to the surface defects on the section 110c, so as to improve the chemical passivation effect of oxygen atoms in the first passivation layer 111 on the section 110c; moreover, compared with the second passivation layer 121 comprising metal oxide material, the lattice of the first passivation layer 111 comprising silicon oxide material is more adapted to the lattice of the substrate in the slice battery 110, which helps to avoid the problem of large lattice mismatch between the section 110c and the second passivation layer 121 when the section 110c is in direct contact with the second passivation layer 121, so as to avoid the problem of increased surface defects caused by lattice mismatch, thereby improving the interface passivation effect on the section 110c.

[0086] The metal oxide material included in the second passivation layer 121 is exemplified below.

[0087] In some examples, the metal element in the metal oxide material includes Al element, that is, the second passivation layer 121 includes aluminum oxide material. On the one hand, the aluminum oxide material enables the second passivation layer 121 to have a high density of fixed negative charges (Q f About 10 12 cm -2 ~10 13 cm -2), which is beneficial to improve the field passivation effect of the second passivation layer 121 on the section 110c, so as to reduce the probability of carrier recombination at the section 110c, thereby helping to improve the photoelectric conversion efficiency of the slice battery 110; on the other hand, in the technology of forming the second passivation layer 121 comprising aluminum oxide material, an appropriate amount of hydrogen ions will also be present in the second passivation layer 121, so that the second passivation layer 121 has a good hydrogen passivation effect on the section 110c. For example, an appropriate amount of hydrogen ions in the second passivation layer 121 can not only effectively saturate the dangling bonds on the section 110c through migration, but also inhibit the recombination of itself with carriers, which is beneficial to ensure that the carriers are effectively converged to the corresponding electrodes in the slice battery 110, so as to further improve the photoelectric conversion efficiency of the slice battery 110.

[0088] In other examples, the metal element in the metal oxide material includes the Mo element, that is, the second passivation layer 121 includes a molybdenum oxide material. On the one hand, the molybdenum oxide material enables the second passivation layer 121 to have a high work function, which is also conducive to the second passivation layer 121 having a good field passivation effect on the cross section 110c; on the other hand, in the technology of forming the second passivation layer 121 including the molybdenum oxide material, the second passivation layer 121 also has a proper amount of hydrogen ions, so that the second passivation layer 121 has a good hydrogen passivation effect on the cross section 110c.

[0089] It should be noted that the above two examples are examples of the metal oxide material in the second passivation layer 121 having a good passivation effect on the cross section 110c. In practical applications, the metal element in the metal oxide material includes at least one of the Al element, the Ti element, the Zn element, the Zr element or the Hf element, which can make the second passivation layer 121 have a high density of fixed negative charges to perform a good field passivation effect on the cross section 110c; the metal element in the metal oxide material includes at least one of the Mo element, the W element or the Ni element, which can make the second passivation layer 121 have a high density of fixed positive charges or a high work function to perform a good field passivation effect on the cross section 110c.

[0090] In some embodiments, reference Figure 7 , Figure 7 This is a schematic diagram of a third partial cross-sectional structure of a solar cell provided in an embodiment of the present disclosure. The passivation layer 101 may further include an intermediate passivation layer 131. The intermediate passivation layer 131 is located between the first passivation layer 111 and the second passivation layer 121. Moreover, the intermediate passivation layer 131 and the first passivation layer 111 both contain silicon elements, and the intermediate passivation layer 131 and the second passivation layer 121 contain the same metal elements.

[0091] It is worth noting that the intermediate passivation layer 131 not only has the same element as the first passivation layer 111, namely, silicon, but also has the same element as the second passivation layer 121, namely, metal. In this way, the intermediate passivation layer 131 is not only conducive to making the lattice at the interface where the intermediate passivation layer 131 and the first passivation layer 111 are in contact more compatible with the silicon element, but also conducive to making the lattice at the interface where the intermediate passivation layer 131 and the second passivation layer 121 are in contact more compatible with the metal element, which is conducive to avoiding the problem of large lattice mismatch between the first passivation layer 111 and the second passivation layer 121 when the first passivation layer 111 and the second passivation layer 121 are in direct contact, so as to avoid the problem of increased surface defects caused by lattice mismatch, thereby improving the interface passivation effect of the passivation layer 101 on the slice battery 110, for example, improving the passivation effect on the cross section 110c.

[0092] In other words, the intermediate passivation layer 131 plays a transitional role to improve the adaptability of the lattice at the interface where the first passivation layer 111, the intermediate passivation layer 131 and the second passivation layer 121 contact each other in sequence, and prevent the occurrence of gaps and dislocation phenomena at the interface where the first passivation layer 111, the intermediate passivation layer 131 and the second passivation layer 121 contact each other in sequence, so as to improve the uniformity of the film layer of the passivation layer 101 itself, thereby improving the interface passivation effect of the passivation layer 101 on the split battery 110. Moreover, it is beneficial to improve the connection strength between the first passivation layer 111 and the intermediate passivation layer 131, and the connection strength between the intermediate passivation layer 131 and the second passivation layer 121 by means of the intermediate passivation layer 131, so as to avoid the mutual slippage or shedding problem between the first passivation layer 111 and the intermediate passivation layer 131, or the intermediate passivation layer 131 and the second passivation layer 121, thereby helping to improve the structural stability of the passivation layer 101.

[0093] In some embodiments, continue to refer to Figure 7 , the material of the intermediate passivation layer 131 includes an oxide having silicon elements and metal elements. In this way, it can be ensured that the intermediate passivation layer 131 not only has the same elements as the first passivation layer 111, but also has the same elements as the second passivation layer 121, so that the intermediate passivation layer 131 serves as a transition layer between the first passivation layer 111 and the second passivation layer 121, and the oxygen atoms in the intermediate passivation layer 131 can be used to further saturate the dangling bonds on the section 110c based on the migration of the oxygen atoms toward the section 110c, so as to further reduce the defect state density of the section 110c, thereby further reducing the recombination center of the section 110c to reduce the probability of carrier recombination.

[0094] In some embodiments, in conjunction with reference Figure 8 and Fig. 9The intermediate passivation layer 131 and the first passivation layer 111 have a first surface e in contact with each other, and the intermediate passivation layer 131 and the second passivation layer 121 have a second surface f in contact with each other; wherein the content of silicon element at the first surface e is higher than that at the second surface f, and the content of metal element at the first surface e is lower than that at the second surface f.

[0095] in, Figure 8 A schematic diagram of a partial cross-sectional structure of a segmented cell and a passivation layer in a solar cell provided in an embodiment of the present disclosure; Fig. 9 for Figure 8 The graph showing the percentage of element contents in the sliced ​​battery and passivation layer.

[0096] It is worth noting that, on the one hand, the first passivation layer 111 contains silicon oxide material. Based on this, the content of silicon element at the first surface e where the intermediate passivation layer 131 contacts the first passivation layer 111 is designed to be higher than that at the second surface f. Compared with the second surface f, it is beneficial to enrich the silicon element at the first surface e, thereby helping to further improve the adaptability of the lattice at the interface where the intermediate passivation layer 131 and the first passivation layer 111 contact by increasing the silicon element content at the first surface e, further reducing the defect state density at the first surface e, thereby further improving the passivation effect of the passivation layer 101 on the cross section 110c. On the other hand, the second passivation layer 121 contains a metal oxide material. Based on this, the content of the metal element at the second surface f where the intermediate passivation layer 131 contacts the second passivation layer 121 is designed to be higher than the content at the first surface e, which is beneficial to enrich the metal element at the second surface f, thereby further improving the adaptability of the lattice at the interface where the intermediate passivation layer 131 and the second passivation layer 121 contact by increasing the content of the metal element at the second surface f, further reducing the defect state density at the second surface f, and further improving the passivation effect of the passivation layer 101 on the section 110c.

[0097] In some embodiments, in conjunction with reference Figure 8 and Fig. 9 , along the direction Z from the first passivation layer 111 to the second passivation layer 121, the content of silicon in the intermediate passivation layer 131 tends to decrease, and the content of metal in the intermediate passivation layer 131 tends to increase. In some cases, the direction Z from the first passivation layer 111 to the second passivation layer 121 is perpendicular to the cross section 110c, in other words, the direction Z is perpendicular to the first direction X.

[0098] It is worth noting that the content of silicon at the first surface e is higher than that at the second surface f, and the content of metal at the first surface e is lower than that at the second surface f, which is conducive to ensuring that the content of silicon in the intermediate passivation layer 131 is decreasing and the content of metal in the intermediate passivation layer 131 is increasing in the direction from the first passivation layer 111 to the second passivation layer 121. In addition, both silicon and metal elements in the intermediate passivation layer 131 are changing in a trend, that is, gradually changing, which is conducive to improving the performance stability of the intermediate passivation layer 131 and avoiding performance mutations caused by sudden changes in the content of elements in the intermediate passivation layer 131.

[0099] In some embodiments, in conjunction with reference Figure 8 and Fig. 9 The intermediate passivation layer 131 may further include oxygen elements. In the direction Z from the first passivation layer 111 to the second passivation layer 121 , the content of oxygen elements in the intermediate passivation layer 131 first increases and then decreases.

[0100] It is worth noting that, in order to improve the adaptability of the lattice at the interface where the intermediate passivation layer 131 contacts the first passivation layer 111, and to improve the adaptability of the lattice at the interface where the intermediate passivation layer 131 contacts the second passivation layer 121, the first surface e where the intermediate passivation layer 131 contacts the first passivation layer 111 is designed to be enriched with silicon elements, and the second surface f where the intermediate passivation layer 131 contacts the second passivation layer 121 is designed to be enriched with metal elements, so that the peak value of the content of the oxygen element in the intermediate passivation layer 131 is located in the middle part in the direction from the first passivation layer 111 to the second passivation layer 121, so as to ensure that one of the two ends of the intermediate passivation layer 131 is rich in silicon elements and the other is rich in metal elements. Based on this, the content of the oxygen element in the intermediate passivation layer 131 is designed to increase first and then decrease, so as to ensure that the passivation layer 101 has a high passivation effect on the cross section 110c.

[0101] It should be noted that, in some embodiments, a parameter showing an increasing trend means that the parameter gradually increases, that is, during the change process, the parameter has been gradually increasing; a parameter showing a decreasing trend means that the parameter gradually decreases, that is, during the change process, the parameter has been gradually decreasing. In other embodiments, a parameter showing an increasing trend means that during the change process, the parameter is increasing as a whole, and in the local change process, the parameter may be gradually decreasing; a parameter showing a decreasing trend means that during the change process, the parameter is decreasing as a whole, and in the local change process, the parameter may be gradually increasing. In other embodiments, a parameter showing an increasing trend may mean that the parameter gradually increases, a parameter showing a decreasing trend may mean that the parameter is decreasing as a whole, and in the local change process, the parameter is gradually increasing; or, a parameter showing an increasing trend may mean that the parameter is increasing as a whole, and in the local change process, the parameter is gradually decreasing, and a parameter showing a decreasing trend means that the parameter is gradually decreasing. The above parameters include but are not limited to the content of silicon element in the middle passivation layer 131 , the content of metal element in the middle passivation layer 131 , and the content of oxygen element in the middle passivation layer 131 .

[0102] also, Fig. 9 The above is only an example of the change trend of the content ratio of the silicon element, the metal element and the oxygen element in the partial area of ​​the slice battery 110 and the passivation layer 101 in the slice battery. In actual applications, the change trend of the content ratio of the silicon element, the metal element and the oxygen element in the slice battery 110 and the passivation layer 101 may also be partially or completely different from the above. Fig. 9 The examples shown have differences. In one example Fig. 9 The metal element may be aluminum.

[0103] In some embodiments, the material of the intermediate passivation layer 131 may be a common oxide of silicon and aluminum, and the material of the second passivation layer 121 may be an aluminum oxide material.

[0104] In some embodiments, reference Figure 8 In the direction Z pointing from the first passivation layer 111 to the second passivation layer 121 , the thickness D1 of the first passivation layer 111 is less than the thickness D3 of the intermediate passivation layer 131 , and the thickness D3 of the intermediate passivation layer 131 is less than the thickness D2 of the second passivation layer 121 .

[0105] It is worth noting that the first passivation layer 111 includes silicon oxide material. When the thickness of the film layer including silicon oxide material along direction Z, i.e. D1, is small, it can ensure that the first passivation layer 111 has a good chemical passivation effect on the section 110c, and compared with forming a first passivation layer 111 with a large thickness, the formation process of the first passivation layer 111 with a smaller D1 is simpler; in addition, the thickness D1 of the first passivation layer 111 is small. When the intermediate passivation layer 131 contains oxygen elements, it is also beneficial to make the oxygen atoms in the intermediate passivation layer 131 easier to migrate to the section 110c, so as to further improve the chemical passivation effect on the section 110c.

[0106] The intermediate passivation layer 131 serves as a transition layer between the first passivation layer 111 and the second passivation layer 121. The intermediate passivation layer 131 may have a suitable thickness D3 along the direction Z, preferably to facilitate the migration of oxygen atoms in the intermediate passivation layer 131 to the cross section 110c. Moreover, the second passivation layer 121 includes a metal oxide material. Along the direction Z, within a certain thickness range, the greater the thickness of the film layer including the metal oxide material, the better the field effect passivation effect of the second passivation layer 121 on the cross section 110c. Therefore, along the direction Z, the thickness D2 of the second passivation layer 121 is designed to be maximum, the thickness D1 of the first passivation layer 111 is designed to be minimum, and the thickness D3 of the intermediate passivation layer 131 is designed to be between D1 and D2. This can ensure that the first passivation layer 111 has a good chemical passivation effect on the cross section 110c, and that the second passivation layer 121 has a good field effect passivation effect on the cross section 110c, and is beneficial to the migration of oxygen atoms in the intermediate passivation layer 131 to the cross section 110c.

[0107] In some embodiments, reference Figure 8 , along the direction Z, the thickness D1 of the first passivation layer 111 may be 1 nm to 10 nm. In some examples, the thickness D1 of the first passivation layer 111 may be 4 nm to 7 nm, such as 4.5 nm, 5 nm, 5.5 nm, 6 nm or 6.5 nm.

[0108] In some embodiments, reference Figure 8 , the thickness D2 of the second passivation layer 121 may be 20 nm to 100 nm along the direction Z. In some examples, the thickness D2 of the second passivation layer 121 may be 40 nm to 60 nm, such as 45 nm, 48 nm, 50 nm, 53 nm, 55 nm or 58 nm.

[0109] In some embodiments, reference Figure 8, the thickness D3 of the intermediate passivation layer 131 may be 4 nm to 15 nm along the direction Z. In some examples, the thickness D3 of the intermediate passivation layer 131 may be 8 nm to 12 nm, such as 8.5 nm, 9 nm, 9.5 nm, 10 nm, 10.5 nm, 11 nm or 11.5 nm.

[0110] In some embodiments, the intermediate passivation layer 131 may further include oxygen elements. The silicon content of the intermediate passivation layer 131 is 2% to 60%, the metal content is 2% to 50%, and the oxygen content is 38% to 50%.

[0111] It should be noted that the silicon content in the intermediate passivation layer 131 is 2% to 60%, which means that the average value of the silicon content in the intermediate passivation layer 131 is in the range of 2% to 60%, and the silicon content in different regions of the intermediate passivation layer 131 may be within the average value or may not be within the average value. Similarly, the metal content in the intermediate passivation layer 131 is 2% to 50%, which means that the average value of the metal content in the intermediate passivation layer 131 is in the range of 2% to 50%, and the metal content in different regions of the intermediate passivation layer 131 may be within the average value or may not be within the average value; the oxygen content in the intermediate passivation layer 131 is 38% to 50%, which means that the average value of the oxygen content in the intermediate passivation layer 131 is in the range of 38% to 50%, and the oxygen content in different regions of the intermediate passivation layer 131 may be within the average value or may not be within the average value.

[0112] In some cases, for the area with the largest silicon content in the intermediate passivation layer 131, such as the first surface e, the silicon content in the area is 40% to 80%, for example, the silicon content in the area can be 60%; for the area with the smallest silicon content in the intermediate passivation layer 131, such as the second surface f, the silicon content in the area is 2% to 5%, for example, the silicon content in the area can be 3%.

[0113] In some cases, for the area with the smallest metal element content in the intermediate passivation layer 131, such as the first surface e, the metal element content in this area is 2% to 5%, for example, the metal element content in this area can be 3%; for the area with the largest metal element content in the intermediate passivation layer 131, such as the second surface f, the metal element content in this area is 30% to 70%, for example, the metal element content in this area can be 50%.

[0114] In some cases, for the area with the largest oxygen content in the intermediate passivation layer 131, such as the middle area of ​​the intermediate passivation layer 131, the oxygen content in this area is 45% to 60%, for example, the oxygen content in this area can be 60%; for the area with the smallest oxygen content in the intermediate passivation layer 131, such as the first surface e or the second surface f, the oxygen content in this area is 20% to 40%, for example, the oxygen content in this area can be 20%.

[0115] It should be noted that, for the intermediate passivation layer 131, the sum of the silicon content, the metal content and the oxygen content may be 100% or may not be 100%. In the case where the sum of the silicon content, the metal content and the oxygen content is not 100%, the intermediate passivation layer 131 also contains other impurity elements, such as hydrogen, so that the intermediate passivation layer 131 has a hydrogen passivation effect on the cross section 110c. It is worth noting that in the technology for forming the second passivation layer 121, it is possible that the second passivation layer 121 contains other impurity elements in addition to silicon, oxygen and metal elements.

[0116] In some embodiments, in conjunction with reference Figure 8 and Fig. 9 , along the direction Z, the first passivation layer 111 has a third surface g away from the second passivation layer 121, and a first surface e close to the second passivation layer 121; wherein the content of silicon element at the third surface g is higher than that at the first surface e, and the content of oxygen element at the third surface g is lower than that at the first surface e.

[0117] It is worth noting that the third surface g is the interface where the first passivation layer 111 and the cross section 110c are in contact. Most of the cross section 110c is formed by the side of the substrate 160 in the split cell 110. The substrate 160 can be a silicon base material. Based on this, the content of silicon element at the third surface g where the first passivation layer 111 and the cross section 110c are in contact is designed to be higher than that at the first surface e. Compared with the first surface e, it is beneficial to enrich the silicon element at the third surface g, thereby facilitating the further improvement of the lattice adaptability at the interface where the first passivation layer 111 and the cross section 110c are in contact by increasing the content of silicon element at the third surface g, further reducing the defect state density at the third surface g, and further improving the passivation effect of the first passivation layer 111 on the cross section 110c. Moreover, in order to make the content of silicon element at the third surface g higher than that at the first surface e, the content of oxygen element at the third surface g is designed to be lower than that at the first surface e, so as to ensure that the first passivation layer 111 has a higher passivation effect on the cross section 110c.

[0118] In some embodiments, in conjunction with reference Figure 8 and Fig. 9 , along the direction Z from the first passivation layer 111 to the second passivation layer 121, the content of silicon in the first passivation layer 111 shows a decreasing trend, and the content of oxygen in the first passivation layer 111 shows an increasing trend. In this way, both silicon and oxygen in the first passivation layer 111 show a trend change, that is, a gradual change, which is conducive to improving the performance stability of the first passivation layer 111 and avoiding performance mutations caused by sudden changes in the content of elements in the first passivation layer 111.

[0119] It should be noted that the above has already described in detail the “increasing trend”, “specific circumstances included in the increasing trend”, “decreasing trend” and “specific circumstances included in the decreasing trend”. The description that the content of silicon element in the first passivation layer 111 shows a decreasing trend and the content of oxygen element in the first passivation layer 111 shows an increasing trend will not be repeated here.

[0120] In some embodiments, along direction Z, the second passivation layer 121 has a fourth surface h away from the first passivation layer 111, and a second surface close to the first passivation layer 111; wherein the content of the oxygen element at the second surface f is higher than that at the fourth surface h, and the content of the metal element at the second surface f is lower than that at the fourth surface h.

[0121] It is worth noting that, whether the first passivation layer 111 and the second passivation layer 121 are in direct contact, or there is an intermediate passivation layer 131 between the first passivation layer 111 and the second passivation layer 121, the content of the oxygen element at the second surface f is designed to be higher than that at the fourth surface h, which is conducive to enriching the oxygen element at the second surface f compared to the fourth surface h, thereby making it more conducive to more oxygen atoms to migrate to the cross section 110c, so as to improve the passivation effect of the passivation layer 101 on the cross section 110c. Moreover, in order to make the content of the oxygen element at the second surface f higher than that at the fourth surface h, the content of the metal element at the second surface f is designed to be lower than that at the fourth surface h, so as to ensure that the second passivation layer 121 has a higher passivation effect on the cross section 110c.

[0122] In some embodiments, in conjunction with reference Figure 8 and Fig. 9 , along the direction Z from the first passivation layer 111 to the second passivation layer 121, the content of oxygen in the second passivation layer 121 shows a decreasing trend, and the content of metal in the second passivation layer 121 shows an increasing trend. In this way, both the oxygen and metal elements in the second passivation layer 121 show a trend change, that is, a gradual change, which is conducive to improving the performance stability of the second passivation layer 121 and avoiding performance mutations caused by sudden changes in the content of elements in the second passivation layer 121.

[0123] It should be noted that the above has already described in detail the “increasing trend”, “specific circumstances included in the increasing trend”, “decreasing trend” and “specific circumstances included in the decreasing trend”. The relevant description that the content of oxygen element in the second passivation layer 121 shows a decreasing trend and the content of metal element in the second passivation layer 121 shows an increasing trend will not be repeated here.

[0124] In some embodiments, the silicon content of the first passivation layer 111 is 60% to 98%, and the oxygen content is 2% to 40%.

[0125] It should be noted that the silicon content in the first passivation layer 111 is 60% to 98%, which means that the average value of the silicon content in the first passivation layer 111 is in the range of 60% to 98%, and the silicon content in different regions of the first passivation layer 111 may be within the average value or may not be within the average value. Similarly, the oxygen content in the first passivation layer 111 is 2% to 40%, which means that the average value of the oxygen content in the first passivation layer 111 is in the range of 2% to 40%, and the oxygen content in different regions of the first passivation layer 111 may be within the average value or may not be within the average value.

[0126] In some cases, for the area with the largest silicon content in the first passivation layer 111, such as the third surface g, the silicon content in the area is 90% to 98%, for example, the silicon content in the area can be 95%; for the area with the smallest silicon content in the first passivation layer 111, such as the first surface e, the silicon content in the area is 40% to 80%, for example, the silicon content in the area can be 60%.

[0127] In some cases, for the area with the smallest oxygen content in the first passivation layer 111, such as the third surface g, the oxygen content in the area is 2% to 5%, for example, the oxygen content in the area may be 3%; for the area with the largest oxygen content in the first passivation layer 111, such as the first surface e, the oxygen content in the area is 20% to 60%, for example, the oxygen content in the area may be 40%.

[0128] It should be noted that, for the first passivation layer 111, the sum of the silicon content ratio and the oxygen content ratio may be 100% or may not be 100%. In the case where the sum of the silicon content ratio and the oxygen content ratio is not 100%, the first passivation layer 111 also contains other impurity elements, such as hydrogen, so that the first passivation layer 111 also has a hydrogen passivation effect on the cross section 110c. It is worth noting that in the technology for forming the first passivation layer 111, it is possible that the first passivation layer 111 contains other impurity elements in addition to silicon, oxygen and metal elements.

[0129] In some embodiments, the metal element content in the second passivation layer 121 is 45% to 65%, and the oxygen element content is 35% to 55%.

[0130] It should be noted that the percentage of metal element content in the second passivation layer 121 being 45% to 65% means that the average value of the percentage of metal element content in the second passivation layer 121 is in the range of 45% to 65%, and the percentage of metal element content in different regions of the second passivation layer 121 may be within the average value or may not be within the average value. Similarly, the percentage of oxygen element content in the second passivation layer 121 being 35% to 55% means that the average value of the percentage of oxygen element content in the second passivation layer 121 is in the range of 35% to 55%, and the percentage of oxygen element content in different regions of the second passivation layer 121 may be within the average value or may not be within the average value.

[0131] In some cases, for the area with the largest metal element content in the second passivation layer 121, such as the fourth surface h, the metal element content in the area is 55% to 75%, for example, the metal element content in the area can be 70%; for the area with the smallest metal element content in the first passivation layer 111, the metal element content in the area is 25% to 50%, for example, the metal element content in the area can be 30%.

[0132] In some cases, for the region with the smallest oxygen content in the second passivation layer 121, the oxygen content in the region is 25% to 45%, for example, the oxygen content in the region may be 30%; for the region with the largest oxygen content in the second passivation layer 121, the oxygen content in the region is 50% to 70%, for example, the oxygen content in the region may be 55%.

[0133] It should be noted that, for the second passivation layer 121, the sum of the silicon content and the metal content may be 100% or may not be 100%. In the case where the sum of the silicon content and the metal content is not 100%, the second passivation layer 121 also contains other impurity elements, such as hydrogen, so that the second passivation layer 121 also has a hydrogen passivation effect on the cross section 110c. It is worth noting that in the technology for forming the second passivation layer 121, it is possible that the second passivation layer 121 contains other impurity elements in addition to silicon, oxygen and metal elements.

[0134] In some embodiments, the first passivation layer 111 may be Si a O b Material, a / b∈[1.5, 49], where a / b represents the ratio of the content of silicon element to the content of oxygen element in the first passivation layer 111.

[0135] In some embodiments, the intermediate passivation layer 131 may be SiAl i O j Material, i / j∈[0.04, 1.31], wherein i / j represents the ratio of the content of aluminum element and oxygen element in the intermediate passivation layer 131 .

[0136] In some embodiments, the second passivation layer 121 may be Al m O n Material, m / n∈[1, 1.2], wherein m / n represents the ratio of the content of aluminum element to the content of oxygen element in the second passivation layer 121 .

[0137] It should be noted that the mathematical formulas containing "a" and "b" in this article are a O b represents the element content ratio of silicon element and oxygen element in the first passivation layer 111. The mathematical formula containing "i" and "j" herein is SiAl i O j represents the element content ratio of aluminum element and oxygen element in the second passivation layer 121. The mathematical formula Al containing "m" and "n" herein is m O n represents the element content ratio of aluminum element and oxygen element in the intermediate passivation layer 131, Si a O b 、SiAl i O j and Al m O n None of them are strict chemical formulas or chemical structures, so Si a O b Material, SiAl i O j Materials and Al m On The materials may include one or more stoichiometric compounds, and / or, one or more non-stoichiometric compounds, and the values ​​of "a" and "b" (if present) may be integers or non-integers, the values ​​of "i" and "j" (if present) may also be integers or non-integers, and the values ​​of "m" and "n" (if present) may also be integers or non-integers.

[0138] As used herein, the term "non-stoichiometric compound" means and includes a compound having a certain element composition that cannot be represented by a ratio of well-defined natural numbers and does not violate the law of definite ratios. Among them, the content of each element in the first passivation layer 111, the second passivation layer 121 and the intermediate passivation layer 131 can be confirmed by testing and measuring using an X-ray energy spectrum (EDS, Energy Dispersive Spectrometer), an electron energy loss spectrum (EELS, Electron energy loss spectroscopy) or a secondary ion mass spectrometer (SIMS, Secondary Ion Mass Spectroscopy). For example, a specific line area or area area is selected for testing using a measuring device.

[0139] In some embodiments, reference Figures 1 to 5 , at least part of the split battery 110 has a side surface 110d that has not been split; Figure 2 and Fig.10 The split battery 110 includes: a substrate 120, the substrate 120 has a first surface 120a and a second surface 120b opposite to each other along a second direction Y; a first passivation film 130, located on the first surface 120a; a second passivation film 140, located on the second surface 120b; a side passivation film 150, located on the side 110d, the side passivation film 110d and the first passivation film 130 contain the same material, or the side passivation film 110d and the second passivation film 140 contain the same material.

[0140] in, Fig.10 A schematic diagram of a fourth partial cross-sectional structure of a solar cell provided in an embodiment of the present disclosure.

[0141] It should be noted that the reference Figure 3 or Figure 4 Each of the split cells 110 has a side surface 110d that has not been split. In practical applications, there are sections 110c formed by the splitting of the four side surfaces of some of the split cells 110. For example, Figure 5 The entire solar cell 100 is divided into 9 sub-cells 110 in a 3*3 array arrangement, and the four side surfaces of the sub-cell 110 located in the middle are all cross sections 110c.

[0142] In some examples, the side passivation film 150, the first passivation film 130 and the second passivation film 140 contain the same material, and the side passivation film 150, the first passivation film 130 and the second passivation film 140 can be formed by the same preparation process, which is beneficial to simplify the preparation process and reduce the preparation cost of the side passivation film 150, the first passivation film 130 and the second passivation film 140.

[0143] In some other examples, the first passivation film 130 and the second passivation film 140 may also be formed by different manufacturing processes, and the side passivation film 150 may be formed by the same manufacturing process as one of the first passivation film 130 and the second passivation film 140 .

[0144] It should be noted that the specific structure of the side passivation film 150 is different from the specific structure of the passivation layer 101. For example, the side passivation film 150 is a single-layer structure, which is different from the stacked structure of the passivation layer 101; or, the side passivation film 150 is also a stacked structure, but the material of at least part of the film layer in the side passivation film 150 is different from the material of at least part of the film layer in the passivation layer 101.

[0145] In some cases, the side passivation film 150 and the passivation layer 101 are not formed by the same manufacturing process.

[0146] In some embodiments, the side passivation film 150 may be a stacked structure of a first side passivation film, a second side passivation film, and a third side passivation film stacked in a direction perpendicular to the second direction Y. In one example, the material of the first side passivation film may include a silicon material, the material of the second side passivation film may include an aluminum oxide material, and the material of the third side passivation film may include a silicon nitride material; wherein, in the direction perpendicular to the second direction Y, the thickness of the second side passivation film may be 5 nm.

[0147] In some embodiments, the side passivation film 150 may be a single-layer structure, and the material of the side passivation film 150 includes silicon oxynitride material. In one example, the thickness of the side passivation film 150 in a direction perpendicular to the second direction Y may be 70 nm.

[0148] In some embodiments, reference Figure 1 , Figure 6 ,or Fig.10 In the split battery 110, the cross section 110c and the side surface 110d are connected to the sub-front surface 110a and the sub-back surface 110b along the second direction Y; Fig.10 The surface of the first passivation film 130 away from the first surface 120a along the second direction Y is the sub-front surface 110a; the surface of the second passivation film 140 away from the second surface 120b along the second direction Y is the sub-back surface 110b.

[0149] It is worth noting that the cross section 110c and the side surface 110d include not only the side surface of the substrate 120 , but also the side surfaces of the first passivation film 130 and the second passivation film 140 . In other words, the cross section 110c and the side surface 110d are both the side surfaces of the entire split battery 110 .

[0150] In some embodiments, the sliced ​​cell 110 may include an IBC cell (Interdigitated Back Contact), a TOPCON (Tunnel Oxide Passivated Contact), or a PERC cell (Passivated emitter and real cell).

[0151] It should be noted that the above three types of batteries may all include the passivation layer 101 , the side passivation film 150 , the first passivation film 130 and the second passivation film 140 in the above embodiments.

[0152] The following description is made by taking the sliced ​​battery 110 as a TOPCON battery as an example.

[0153] In some embodiments, in conjunction with reference Fig.10 and Fig.11 , Fig.11 The fifth partial cross-sectional structure schematic diagram of a solar cell provided in an embodiment of the present disclosure, the base 120 may include: a substrate 160, the substrate 160 having a third surface 160a and a fourth surface 160b opposite to each other along the second direction Y, the third surface 160a being close to the first surface 120a, and the fourth surface 160b being close to the second surface 120b; an emitter 170, located on the third surface 160a; a tunneling dielectric layer 180, located on the fourth surface 160b; and a doped conductive layer 190, located on a side of the tunneling dielectric layer 180 away from the fourth surface 160b. The first passivation film 130 is located on a side of the emitter 170 away from the third surface 160a, and the second passivation film 140 is located on a side of the doped conductive layer 190 away from the tunneling dielectric layer 180.

[0154] In some cases, the substrate 160 is a silicon base material, such as one or more of single crystal silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. In some examples, the substrate 160 may be an N-type semiconductor substrate, the substrate 160 may include an N-type doping element (such as phosphorus, arsenic, antimony, etc.), the emitter 170 may include a P-type doping element, and the emitter 170 forms a PN junction with the substrate 160.

[0155] In some cases, continue to refer to Fig.11The split cell 110 may further include: a first electrode 122 , the first electrode 122 being in electrical contact with the emitter 170 . In one example, the first electrode 122 penetrates the first passivation film 130 and is in electrical contact with the emitter 170 .

[0156] In some cases, continue to refer to Fig.11 The split cell 110 may further include a second electrode 123 , the second electrode 123 being in electrical contact with the doped conductive layer 190 . In one example, the second electrode 123 penetrates the second passivation film 140 and is in electrical contact with the doped conductive layer 190 .

[0157] In the above-mentioned various embodiments, in some embodiments, the first passivation film 130 and the second passivation film 140 can both be a single-layer structure or a stacked-layer structure, and the materials of the first passivation film 130 and the second passivation film 140 can both be at least one of silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride oxide, titanium oxide, hafnium oxide or aluminum oxide.

[0158] In some embodiments, the split battery 110 may further include: welding points, located on the first electrode 122 and the second electrode 123, to facilitate the subsequent use of welding strips and welding points to achieve electrical connection between adjacent split batteries 110. Some welding points will be described in detail later.

[0159] It is worth noting that “the passivation layer 101 is at least located on the cross section 110c” includes at least the following embodiments:

[0160] In some embodiments, reference Fig.12 , Fig.12 This is a schematic diagram of a sixth partial cross-sectional structure of a solar cell provided by an embodiment of the present disclosure, in which the passivation layer 101 is also located on a portion of the surface of the first passivation film 130 away from the first surface 120a along the second direction Y. It should be noted that in the step of forming the passivation layer 101 covering the cross section 110c, the raw materials required for preparing the passivation layer 101 may diffuse a certain distance to the surface of the first passivation film 130 connected to the cross section 110c, and thus the passivation layer 101 is also formed on the portion of the surface of the first passivation film 130 along the second direction Y away from the first surface 120a.

[0161] In some cases, the area ratio of the surface of the first passivation film 130 away from the first surface 120a along the second direction Y, where the passivation layer 101 is disposed, to the entire surface is not greater than 5%. For example, the area ratio of the surface of the first passivation film 130 where the passivation layer 101 is disposed to the entire surface may be 4.5%, 4%, 3.5%, 3%, 2.5% or 2%, etc. In this way, the raw materials required for preparing the passivation layer 101 diffuse to the surface of the first passivation film 130 over a shorter distance, which helps to avoid the passivation layer 101 from being formed on the solder joints used to connect adjacent sub-cells 110, so as not to hinder the sub-cell interconnection step in the process of forming a photovoltaic module. It is worth noting that, especially for solar cells that need to make full use of the utilization rate of the first surface 120a, that is, to increase the area of ​​the first surface 120a that receives light, the gate lines located on the first surface 120a, that is, the electrodes are getting thinner and thinner, or the closer the gate lines are to the edge of the first surface 120a, the more beneficial it is to improve the conversion efficiency of the encapsulated photovoltaic module by controlling the area ratio of the area where the passivation layer 101 is provided on the surface of the first passivation film 130 and the entire surface.

[0162] In other embodiments, reference Fig.13 , Fig.13 This is a schematic diagram of a seventh partial cross-sectional structure of a solar cell provided by an embodiment of the present disclosure, in which the passivation layer 101 is also located on a portion of the surface of the second passivation film 140 away from the second surface 120b along the second direction Y. It should be noted that in the step of forming the passivation layer 101 covering the cross section 110c, the raw materials required for preparing the passivation layer 101 may diffuse a certain distance to the surface of the second passivation film 140 connected to the cross section 110c, and thus the passivation layer 101 is also formed on the portion of the surface of the second passivation film 140 along the second direction Y away from the second surface 120b.

[0163] In some cases, the area ratio of the surface of the second passivation film 140 away from the second surface 120b along the second direction Y, where the passivation layer 101 is disposed, to the entire surface is not greater than 5%. For example, the area ratio of the surface of the first passivation film 130 where the passivation layer 101 is disposed to the entire surface may be 4.5%, 4%, 3.5%, 3%, 2.5% or 2%, etc. In this way, the raw materials required for preparing the passivation layer 101 diffuse to the surface of the second passivation film 140 over a shorter distance, which is also beneficial to avoid the passivation layer 101 from being formed on the solder joints used to connect adjacent sub-cells 110, so as not to hinder the sub-cell interconnection step in the process of forming a photovoltaic module.

[0164] In some other embodiments, reference Fig.14 , Fig.14This is a schematic diagram of the eighth partial cross-sectional structure of a solar cell provided in an embodiment of the present disclosure, in which the passivation layer 101 is also located on a partial surface of the first passivation film 130 away from the first surface 120a along the second direction Y, and the passivation layer 101 is also located on a partial surface of the second passivation film 140 away from the second surface 120b along the second direction Y.

[0165] In some cases, on the surface of the first passivation film 130 away from the first surface 120a along the second direction Y, the area ratio of the surface on which the passivation layer 101 is provided to the entire surface is not greater than 5%, and, on the surface of the second passivation film 140 away from the second surface 120b along the second direction Y, the area ratio of the surface on which the passivation layer 101 is provided to the entire surface is not greater than 5%.

[0166] It should be noted that the description of the solder joints in the above three embodiments can be referred to in the following embodiments and will not be repeated here.

[0167] In some embodiments, in conjunction with reference Fig.12 and Fig.15 The solar cell may further include: an edge solder joint 102; the edge solder joint 102 is located at the edge of the first surface 120a, and there is a gap between the passivation layer 101 located on the surface of the first passivation film 130 and the edge solder joint 102; in other embodiments, reference Fig.13 , the edge solder joint (not shown) is located at the edge of the second surface 120b, and there is a gap between the passivation layer 101 located on the surface of the second passivation film 140 and the edge solder joint 102; in some other embodiments, reference Fig.14 The edge solder joint (not shown) is located at both the edge of the first surface 120 a and the edge of the second surface 120 b , and there is a distance between the passivation layer 101 and the edge solder joint (not shown).

[0168] This helps to ensure that the passivation layer 101 does not cover the edge solder joints 102, and further does not cover the solder joints in the middle area of ​​the segmented cell 110, which helps to further prevent the passivation layer 101 from interfering with the sub-cell interconnection step in the process of forming a photovoltaic module.

[0169] It should be noted that Fig.15 A partial top view of a solar cell provided by an embodiment of the present disclosure. In addition, based on the type of the split cell 110, the edge solder joint 102 may be located only at the edge of one of the first surface 120a and the second surface 120b, or may be located at the edge of the first surface 120a and the edge of the second surface 120b. In addition, Fig.15 Only the edge welding point 102 on the first electrode 122 in the edge region is illustrated. In actual applications, there are welding points on the first electrode in the middle region, and there are welding points on the second electrode.

[0170] In summary, the angle between the cross section 110c and the sub-back side 110b formed by the splitting process on the slice cell 110 is not a right angle, that is, the entire solar cell 100 is beveled to form the slice cell 110. For the sub-front side 110a and the sub-back side 110b on the slice cell 110, the cross section 110c on the slice cell 110 can be regarded as an inclined surface. Based on this, compared with splitting the entire solar cell 100 along the second direction Y to form the cross-section 110c of the sliced ​​cell 110, the atomic arrangement density on the inclined cross-section 110c designed on the sliced ​​cell 110 in one embodiment of the present disclosure is smaller, and the covalent bond surface density is smaller, so the connection between adjacent atoms on the cross-section is not firm, which is more conducive to promoting the passivation layer 101 located on the cross-section 110c to form a bond with the dangling bonds on the cross-section 110c, that is, making it easier for the passivation layer 101 to saturate the dangling bonds on the cross-section 110c, and the passivation layer 101 can also passivate other surface defects on the cross-section 110c, which is conducive to further improving the ability of the passivation layer 101 to reduce the defect state density of the cross-section 110c, so as to further reduce the recombination center of the cross-section 110c to reduce the carrier recombination probability. In other words, designing the cross section 110c of the segmented cell 110 to be inclined rather than perpendicular to its sub-back side 110b and cooperating with the passivation function of the passivation layer 101 is beneficial to further improve the passivation effect of the passivation layer 101 on the cross section 110c, so as to further reduce the probability of carrier recombination on the cross section 110c, increase the carrier lifespan, and thus further improve the photoelectric conversion efficiency of the segmented cell 110.

[0171] Another embodiment of the present disclosure also provides a method for preparing a solar cell, which is used to prepare the solar cell provided by the above embodiment. The method for preparing a solar cell provided by another embodiment of the present disclosure will be described in detail below in conjunction with the accompanying drawings. It should be noted that the parts that are the same or corresponding to the above embodiment will not be repeated here.

[0172] refer to Figures 1 to 5 , a method for preparing a solar cell, comprising: providing a whole solar cell 100; dividing the whole solar cell 100 with the entire thickness along a first direction X to form at least two slice cells 110, and the thickness of the whole solar cell 100 is the same as the thickness of the slice cell 110 along a second direction Y; wherein the second direction Y is the thickness direction of the slice cell 110, and the first direction X intersects with the second direction Y, the slice cell 110 has a sub-front side 110a and a sub-back side 110b arranged opposite to each other along the second direction Y, and the slice cell 110 also has a cross section 110c formed by the above-mentioned treatment, and two complementary angles are formed between the planes where the cross section 110c and the sub-back side 110b are located, and one of the angles is an acute angle; and forming a passivation layer 101 at least on the cross section 110c.

[0173] In some embodiments, the step of forming the passivation layer 101 may include the following situations: In some situations, referring to Figure 2 , the passivation layer 101 is formed only on the section 110c; in other cases, referring to Fig.12 On the basis of forming the passivation layer 101 on the cross section 110c, the passivation layer 101 is also formed on a portion of the surface of the sub-front side 110a of the split cell 110; in some other cases, referring to Fig.13 On the basis of forming the passivation layer 101 on the cross section 110c, the passivation layer 101 is also formed on a portion of the surface of the sub-back side 110b of the split battery 110; in other cases, referring to Fig.14 On the basis of forming the passivation layer 101 on the cross section 110 c , the passivation layer 101 is formed on a portion of the surface of the sub-front side 110 a and a portion of the surface of the sub-back side 110 b of the split battery 110 .

[0174] In some embodiments, reference Figure 6 The step of forming the passivation layer 101 may further include: forming a first passivation layer 111 at least on the cross section 110 c ; and forming a second passivation layer 121 on a side of the first passivation layer 111 away from the split battery 110 .

[0175] In one example, reference Fig.11 After forming the first passivation layer 111 and before forming the second passivation layer 121, the preparation method may further include: forming an intermediate passivation layer 131 on a side of the first passivation layer 111 away from the split battery 110; the step of forming the second passivation layer 121 includes: forming the second passivation layer 121 on a side of the intermediate passivation layer 131 away from the first passivation layer 111.

[0176] It is worth noting that along the second direction Y, the thickness of the whole solar cell 100 is the same as the thickness of the slice cell 110, and the slice cell 110 is formed by cutting the whole solar cell 100 from its front side 100a to its back side 100b, or from its back side 100b to its front side 100a. Moreover, the cutting direction of the whole solar cell 100 is limited, that is, the same whole solar cell 100 is divided along the first direction X to form the slice cell 110, and the first direction X intersects with the thickness direction of the slice cell 110. In other words, the whole solar cell 100 is beveled to form the slice cell 110, and for the sub-front side 110a and the sub-back side 110b on the slice cell 110, the cross section on the slice cell 110 can be regarded as an inclined surface.

[0177] Based on this, by taking advantage of the smaller atomic arrangement density and smaller covalent bond surface density on the inclined section 110c designed on the slice battery 110, after the passivation layer 101 is formed on the section 110c, it is more conducive to promoting the passivation layer 101 to form bonds with the dangling bonds on the section 110c, so as to further improve the ability of the passivation layer 101 to reduce the defect state density of the section 110c, further reduce the probability of carrier recombination on the section 110c, and increase the carrier lifetime, thereby further improving the photoelectric conversion efficiency of the slice battery 110.

[0178] Another embodiment of the present disclosure further provides a photovoltaic module, which is used to convert received light energy into electrical energy. The following will describe in detail a method for preparing a solar cell provided by another embodiment of the present disclosure in conjunction with the accompanying drawings. Fig.16 A schematic diagram of a partial three-dimensional structure of a photovoltaic assembly provided by another embodiment of the present disclosure; Fig.17 for Fig.16 A schematic diagram of a cross-sectional structure along the cross-sectional direction MM1. It should be noted that the parts identical or corresponding to the above-mentioned embodiments are not described in detail here.

[0179] refer to Fig.16 and Fig.17 The photovoltaic module includes: a battery string, which is formed by connecting multiple solar cells 40 provided in the above embodiments, or by connecting multiple solar cells 40 prepared by the preparation method provided in the above embodiments; a packaging film 41, which is used to cover the surface of the battery string; and a cover plate 42, which is used to cover the surface of the packaging film 41 away from the battery string.

[0180] It is worth noting that the solar cells 40 are electrically connected to form a plurality of cell strings, and the plurality of cell strings are electrically connected in series and / or in parallel. Since the solar cell 40 includes a sliced ​​cell 110, and the sliced ​​cell 110 is formed by segmenting the entire solar cell 100, the power loss of the photovoltaic module can be improved by the current drop of the sliced ​​cell 110, so as to improve the photoelectric conversion efficiency of the photovoltaic module.

[0181] In some embodiments, reference Fig.17 , multiple battery strings can be electrically connected through the conductive tape 402. Fig.17 Only one positional relationship between solar cells is illustrated, that is, the arrangement direction of the electrodes with the same polarity of the cells is the same, or the electrodes with positive polarity of each cell are arranged toward the same side, so that the conductive tape connects different sides of two adjacent cells. In some embodiments, the cells can also be arranged in the order of electrodes with different polarities facing the same side, that is, the electrodes of multiple adjacent cells are arranged in the order of the first polarity, the second polarity, and the first polarity, and the conductive tape connects two adjacent cells on the same side.

[0182] In some embodiments, no intervals are set between the battery cells, that is, the battery cells overlap each other.

[0183] 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 side or the back side of the solar cell 40, and the second encapsulation layer covers the other of the front side or the back side of the solar cell 40. Specifically, at least one of the first encapsulation layer or the second encapsulation layer can be an organic encapsulation film such as a polyvinyl butyral (PVB) film, an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene co-elastomer (POE) film or a polyethylene terephthalate (PET) film.

[0184] In some cases, there is a boundary between the first encapsulation layer and the second encapsulation layer before lamination. After the lamination process, the photovoltaic module is formed and there is no longer the concept of the first encapsulation layer and the second encapsulation layer, that is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0185] In some embodiments, the cover plate 42 may be a glass cover plate, a plastic cover plate or the like with a light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulation film 41 may be a concave-convex surface, thereby increasing the utilization rate of the incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate is opposite to the first encapsulation layer, and the second cover plate is opposite to the second encapsulation layer.

[0186] In some embodiments, reference Fig.16 The solar cells 40 in the battery string are arranged along the direction U, and the main grids of two adjacent solar cells 40 in the battery string are staggered in the third direction Z. For the photovoltaic module, by setting the main grids of two adjacent solar cells 40 in the battery string to be staggered in the third direction Z, different potentials of the photovoltaic module can be tested, thereby improving the reliability of the test results.

[0187] In some embodiments, the photovoltaic cell 40 includes, but is not limited to, one or any combination of PERC cells (Passivated Emitter Rear Cell), IBC cells (Interdigitated Back Contact), TOPCon cells (Tunnel Oxide Passivated Contact), HIT / HJT cells (Heterojunction Technology heterojunction cells), solar thin-film cells, and stacked cells. Among them, solar thin-film cells include, but are not limited to, perovskite solar thin-film cells, copper indium selenide solar thin-film cells, gallium arsenide solar thin-film cells, and cadmium sulfide solar thin-film cells. Stacked cells include, but are not limited to, perovskite cells superimposed on crystalline silicon cells, perovskite cells superimposed on perovskite cells, and perovskite cells superimposed on thin-film cells.

[0188] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in practical applications, various changes can be made to them in form and detail 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, so the protection scope of the embodiments of the present disclosure shall be based on the scope defined in the claims.

Claims

1. A solar cell, characterized in that: include: Slice cells, at least two of which are formed by segmenting the same whole solar cell along a first direction, the whole solar cell having a front side and a back side arranged opposite to each other along a second direction, the slice cell having a sub-front side and a sub-back side arranged opposite to each other along the second direction, the sub-front side of at least two of the slice cells formed based on the same whole solar cell being a partial area of ​​the front side, and the sub-back side of at least two of the slice cells formed based on the same whole solar cell being a partial area of ​​the back side; The second direction is the thickness direction of the split battery, and the first direction intersects with the second direction. The split battery has a cross section formed by the segmentation process, and two complementary angles are formed between the cross section and the plane where the sub-back surface is located, and one of the angles is an acute angle. The passivation layer is at least located on the cross section.

2. The solar cell according to claim 1, characterized in that: A single split cell includes at least one section, and the passivation layer is located on each section.

3. The solar cell according to claim 1, characterized in that In one of the slice batteries, the area of ​​the sub-front side is larger than the area of ​​the sub-back side, a first angle is formed between at least one of the cross-sections and the sub-back side, and the complementary angle of the first angle is the acute angle; and / or, in another of the slice batteries, the area of ​​the sub-front side is smaller than the area of ​​the sub-back side, a second angle is formed between at least one of the cross-sections and the sub-back side, and the second angle is the acute angle.

4. The solar cell according to any one of claims 1 to 3, characterized in that The acute angle is 45° to 80°.

5. The solar cell according to claim 1, characterized in that: Along the third direction, the passivation layer includes at least a first passivation layer and a second passivation layer stacked together, the first passivation layer includes a silicon oxide material, the second passivation layer includes a metal oxide material, the metal elements in the metal oxide material include at least one of Al element, Ti element, Zn element, Zr element, Hf element, Mo element, W element or Ni element, and the third direction is perpendicular to the cross-section.

6. The solar cell according to claim 5, characterized in that: The passivation layer further includes an intermediate passivation layer, which is located between the first passivation layer and the second passivation layer. The intermediate passivation layer and the first passivation layer both contain silicon elements, and the intermediate passivation layer and the second passivation layer contain the same metal element.

7. The solar cell according to claim 6, characterized in that: The material of the intermediate passivation layer includes an oxide having the silicon element and the metal element.

8. The solar cell according to claim 1, characterized in that The orthographic projection of the split battery on the sub-back surface is in the shape of a rectangle, and some corners of the rectangle are rounded.

9. A method for preparing a solar cell, characterized in that: include: Provide whole solar cells; Along a first direction, a whole solar cell with a whole thickness is divided to form at least two split cells, and along a second direction, the thickness of the whole solar cell is the same as the thickness of the split cells; The second direction is the thickness direction of the split battery, and the first direction intersects the second direction. The split battery has a sub-front side and a sub-back side that are arranged opposite to each other along the second direction. The split battery also has a cross section formed by the segmentation process. Two complementary angles are formed between the cross section and the plane where the sub-back side is located, and one of the angles is an acute angle. A passivation layer is formed at least on the cross section.

10. A photovoltaic module, characterized in that: include: A battery string formed by connecting a plurality of solar cells according to any one of claims 1 to 8, or by connecting a plurality of solar cells formed by the preparation method according to claim 9; A packaging film, used to cover the surface of the battery string; The cover plate is used to cover the surface of the packaging film facing away from the battery string.

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