Back contact battery and photovoltaic module

Abstract

The invention provides a back contact battery, which comprises a semiconductor substrate, a first doping layer and a second doping layer, the main body part of the first doping layer and the main body part of the second doping layer are alternately distributed on one side of the backlight surface of the semiconductor substrate, and the conduction types of the first doping layer and the second doping layer are opposite; wherein the first part of the second doping layer is overlapped above one part of the first doping layer to form a laminated structure; and one part, close to the second part of the laminated structure, of the second doping layer is tilted in the direction away from the laminated structure to form a tilted part. The invention also provides a photovoltaic module. The back contact cell provided by the invention can realize balance between improvement of a hot spot effect and guarantee of photoelectric conversion efficiency.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a back contact cell and a photovoltaic module. Background Art

[0002] A back-contact cell refers to a solar cell with no electrodes on the light-facing side of the cell, and both the positive and negative electrodes are arranged on the back-light side of the cell. This can reduce the shading of the electrodes to the cell, increase the short-circuit current of the cell, and improve the energy conversion efficiency of the cell. During the actual use of the back-contact battery, bird droppings, leaves, dust and other obstructions may fall onto the component, blocking the cell at the corresponding position. When the cell is blocked, the temperature will rise and produce a hot spot effect. If the temperature generated by the hot spot exceeds a certain temperature value, it will cause problems such as delamination of the photovoltaic module, burning of the back panel, and cracking of the glass, which will cause the entire solar cell to be scrapped, and in severe cases may cause a fire risk. However, existing back-contact batteries with anti-hot spot structures have problems such as excessive leakage loss and excessive local heating.

[0003] Therefore, there is a need to provide an improved back contact cell and photovoltaic module to overcome or reduce at least some of the disadvantages existing in the above-mentioned prior art. Summary of the invention

[0004] In a first aspect of the present invention, a back-contact cell is provided, wherein the back-contact cell comprises: a semiconductor substrate, a first doping layer and a second doping layer;

[0005] The main body of the first doping layer and the main body of the second doping layer are alternately distributed on the backlight side of the semiconductor substrate, and the first doping layer and the second doping layer have opposite conductivity types;

[0006] The first portion of the second doped layer overlaps a portion of the first doped layer to form a stacked structure; and a portion of the second portion of the second doped layer close to the stacked structure is tilted away from the stacked structure to form a tilted portion.

[0007] In the back-contact battery of the present invention, by overlapping a first part of the second doping layer above a part of the first doping layer to form a stacked structure, a built-in diode with a lower reverse breakdown voltage can be formed at the electrical connection between the first doping layer and the second doping layer, which is beneficial to making the back-contact battery have a lower reverse breakdown voltage when shaded, and reducing the hot-spot risk of the back-contact battery; by tilting a part of the second part of the second doping layer close to the stacked structure away from the stacked structure to form a tilted part, a gap can be formed between the tilted part and the stacked structure, and the existence of this gap can separate a partial area of the first doping layer in the stacked structure from the second part of the second doping layer, so that a leakage area cannot be formed at this gap, dispersing the leakage points and avoiding local overheating; the existence of the tilted part can reduce the proportion of the leakage contact area, minimizing the loss of the battery conversion efficiency caused by the PN junction contact while improving the hot-spot effect.

[0008] Optionally, another part of the second part of the second doping layer is in close contact with the stacked structure to form a fitting part;

[0009] Wherein, in a first direction, a plurality of tilted parts and a plurality of fitting parts are alternated; the first direction is parallel to the extending direction of the side surface of the first doping layer in the stacked structure opposite to the second part of the second doping layer.

[0010] Optionally, the first doping layer in the stacked structure is electrically connected to the second part of the second doping layer, and a side docking surface is formed on the side surface of the first doping layer in the stacked structure opposite to the second part of the second doping layer, wherein the side docking surface has a bending structure.

[0011] Optionally, the bending structure includes a plurality of docking sections bent and connected in a direction parallel to the backlight surface.

[0012] Optionally, there are a plurality of protruding parts protruding towards the second part of the second doping layer and a plurality of recessed parts recessed away from the second part of the second doping layer in the docking section.

[0013] Optionally, the tilted part is formed at the position of the second part of the second doping layer corresponding to the protruding part; or

[0014] The tilted part is formed at the position of the second part of the second doping layer corresponding to the recessed part; or

[0015] The tilted part is formed at the position of the second part of the second doping layer corresponding to the recessed part adjacent to the protruding part.

[0016] Optionally, an air gap is defined between the tilted part, the first doping layer in the stacked structure, and the semiconductor substrate.

[0017] Optionally, the back-contact battery further includes a surface passivation layer that covers the first doped layer, the second doped layer, and the stacked structure. The surface passivation layer extends into the air gap at the upturned portion, thereby filling part or all of the air gap.

[0018] Optionally, there is a spacer region between the main body portion of the first doped layer and the main body portion of the second doped layer;

[0019] The second doped layer further includes an extension portion of the second doped layer. The extension portion of the second doped layer extends across the spacer region and extends over a part of the first doped layer to form a stacked structure, where the first part and the second part of the second doped layer are part of the extension portion of the second doped layer.

[0020] Optionally, there is a spacer region between the main body portion of the first doped layer and the main body portion of the second doped layer;

[0021] The first doped layer further includes an extension portion of the first doped layer, and the second doped layer further includes an extension portion of the second doped layer. The extension portion of the second doped layer overlaps above the extension portion of the first doped layer in the spacer region to form a stacked structure, where the first part and the second part of the second doped layer are part of the extension portion of the second doped layer.

[0022] Optionally, there is a spacer region between the main body portion of the first doped layer and the main body portion of the second doped layer;

[0023] The first doped layer further includes an extension portion of the first doped layer. The extension portion of the first doped layer extends across the spacer region and extends under the main body portion of the second doped layer to form a stacked structure, where the first part of the second doped layer is part of the main body portion of the second doped layer.

[0024] In a second aspect of the present invention, a photovoltaic module is provided, including:

[0025] A battery string formed by electrically connecting a plurality of the aforementioned back-contact batteries; and

[0026] An encapsulation layer covering the surface of the back-contact battery.

[0027] Those skilled in the art will understand the above and other objects, advantages, and features of the present invention more clearly according to the following detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. Description of the Drawings

[0028] The features, advantages, and exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which the same reference numerals indicate the same elements, and among them:

[0029] Figure 1It is a partial schematic view of some components of a back-contact battery according to an embodiment of the present invention, in which a warped portion is shown.

[0030] Figure 2 is Figure 1 Another partial schematic view of the back-contact battery, in which a fitting portion is shown.

[0031] Figure 3 is Figure 1 A schematic layout diagram of the side docking surface, the warped portion and the fitting portion of the back-contact battery.

[0032] Figure 4 It is a partial schematic view of some components of a back-contact battery according to another embodiment of the present invention.

[0033] Figure 5 is Figure 1 A schematic view of an implementation manner of the back-contact battery.

[0034] Figure 6 is Figure 1 A schematic view of another implementation manner of the back-contact battery.

[0035] Figure 7 It is a cross-sectional schematic view of the back-contact battery according to an embodiment of the present invention.

[0036] Figure 8 It is a schematic diagram of a distribution relationship between a first doping layer and a second doping layer of the back-contact battery according to an embodiment of the present invention.

[0037] Figure 9 It is a schematic diagram of another distribution relationship between a first doping layer and a second doping layer of the back-contact battery according to an embodiment of the present invention.

[0038] Figure 10 is Figure 1 A schematic view of a single side docking surface of the back-contact battery.

[0039] Figure 11 It is an SEM image of a back-contact battery with a warped portion. Specific Embodiments

[0040] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0041] Various structural schematic diagrams according to embodiments of the present invention are shown in the accompanying drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary, and in practice, there may be deviations due to manufacturing tolerances or technical limitations. And those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0042] In the context of the present invention, when a layer / element is referred to as being "on" another layer / element, the layer / element can be directly on the other layer / element, or there can be an intermediate layer / element between them. Additionally, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element can be "under" the other layer / element. In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0043] Furthermore, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, the meaning of "a plurality" is two or more, unless otherwise specifically defined.

[0044] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "coupled" 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 directly connected or indirectly connected through an intermediate medium, and it can be the internal communication 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 present invention can be understood according to specific circumstances.

[0045] Embodiments of the present invention provide a back-contact battery 100, wherein, as Figure 1As shown, the back-contact battery 100 includes: a semiconductor substrate 101, a first doping layer 200, and a second doping layer 300; the main body 204 of the first doping layer and the main body 304 of the second doping layer are alternately distributed on one side of the backlight surface of the semiconductor substrate 101, and the conduction types of the first doping layer 200 and the second doping layer 300 are opposite; wherein, a first portion 351 of the second doping layer 300 overlaps a portion of the first doping layer 200 to form a stacked structure 600; and wherein, a portion of a second portion 352 of the second doping layer 300 near the stacked structure 600 warps away from the stacked structure 600 to form a warped portion 361.

[0046] In the back-contact battery 100 of the embodiment of the present invention, by overlapping a first portion 351 of the second doping layer 300 on a portion of the first doping layer 200 to form a stacked structure 600, an internal diode with a lower reverse breakdown voltage can be formed at the electrical connection between the first doping layer 200 and the second doping layer 300, which is beneficial to making the back-contact battery 100 have a lower reverse breakdown voltage when being blocked, and reducing the hot-spot risk of the back-contact battery 100; by warping a portion of a second portion 352 of the second doping layer 300 near the stacked structure 600 away from the stacked structure 600 to form a warped portion 361, a gap can be formed between the warped portion 361 and the stacked structure 600. The existence of the gap can separate a partial area of the first doping layer 200 and the second portion 352 of the second doping layer 300 in the stacked structure 600, so that a leakage area cannot be formed at this gap, and the leakage points are dispersed to avoid local overheating. For example, an air gap 363 can be formed between the warped portion 361 and the stacked structure 600, and the existence of the air gap 363 can separate a partial area of the first doping layer 200 and the second portion 352 of the second doping layer 300 in the stacked structure 600; or for another example, a film layer gap can also be formed between the warped portion 361 and the stacked structure 600, that is, a partial area of the first doping layer 200 and the second portion 352 of the second doping layer 300 in the stacked structure 600 can be separated by the existence of an insulating or semi-insulating film layer. The existence of the warped portion 361 can reduce the proportion of the leakage contact area, so that while improving the hot-spot effect, the loss of the battery conversion efficiency caused by the PN region contact is minimized; at the same time, physical insulation can be formed through the air gap 363. Compared with a dielectric layer with certain conductivity (such as an interface passivation layer, etc.), the insulation effect of the air gap 363 is stronger and the reliability is higher, which can enhance the local insulation effect and is beneficial to the forward power generation of the back-contact battery 100. Therefore, by adjusting the total number of settings, size, etc. of the warped portion 361, a balance can be achieved between improving the hot-spot effect and ensuring the photoelectric conversion efficiency.

[0047] An embodiment of the present invention also provides a photovoltaic module (not shown in the figure). The photovoltaic module includes a battery string formed by electrically connecting the foregoing back-contact battery 100 and a packaging layer covering the surface of the battery string. The photovoltaic module has an effect similar to that of the foregoing back-contact battery 100.

[0048] The back-contact battery 100 of the embodiment of the present invention will be introduced in more detail below with reference to the drawings.

[0049] A back-contact battery 100 refers to a solar cell in which the light-facing surface 111 of the cell has no electrodes, and the positive electrode and the negative electrode are both disposed on the backlight surface 112 side of the cell, so that the shielding of the cell by the electrodes can be reduced, the short-circuit current of the cell can be increased, and the energy conversion efficiency of the cell can be improved.

[0050] There are two possible distribution relationships between the first doping layer 200 and the second doping layer 300 of the back-contact battery 100, as shown respectively in Figure 8 and Figure 9 shown.

[0051] It can be understood that in this article, the "first doping layer" and the "second doping layer" are only for convenience of description. From aspects such as function and setting position, the first doping layer 200 and the second doping layer 300 can be interchanged. Alternatively, the back-contact battery 100 includes: a semiconductor substrate 101, a first doping layer 200, and a second doping layer 300; the main body portion 204 of the first doping layer and the main body portion 304 of the second doping layer are alternately distributed on the backlight surface side of the semiconductor substrate 101, and the conductive types of the first doping layer 200 and the second doping layer 300 are opposite; wherein, a first part of the first doping layer 200 overlaps a part of the second doping layer 300 to form a stacked structure 600; and wherein, a part of a second part of the first doping layer 200 close to the stacked structure 600 warps away from the stacked structure 600 to form a warped portion 361.

[0052] The following will be combined with Figure 8 to illustrate the back-contact battery 100 of the embodiment of the present application.

[0053] In Figure 8 , the first doping layer 200 includes the main body portion 204 of the first doping layer, and the second doping layer 300 includes the main body portion 304 of the second doping layer. The main body portion 204 of the first doping layer and the main body portion 304 of the second doping layer are alternately distributed at intervals in a strip shape. There is an interval region 190 between the main body portion 204 of the first doping layer and the main body portion 304 of the second doping layer. Specifically, Figure 8In this case, the main body portion 204 of the first doping layer only includes the strip-shaped portion 201 of the first doping layer. The main body portion 304 of the second doping layer only includes the strip-shaped portion 301 of the second doping layer. The spacer region 190 is formed between the strip-shaped portion 201 of the first doping layer and the strip-shaped portion 301 of the second doping layer. Here, the region where the strip-shaped portion 201 of the first doping layer is located is the first doping region 191, the region where the strip-shaped portion 301 of the second doping layer is located is the second doping region 192, and the spacer region 190 is formed between the first doping region 191 and the second doping region 192.

[0054] The first doping layer 200 may further include an extension portion 203 of the first doping layer. The extension portion 203 of the first doping layer extends from a partial region of the main body portion 204 of the first doping layer toward the second doping layer 300, that is, extends from a partial region of the strip-shaped portion 201 of the first doping layer toward the strip-shaped portion 301 of the second doping layer.

[0055] The second doping layer 300 may further include an extension portion 303 of the second doping layer. The extension portion 303 of the second doping layer extends from a partial region of the main body portion 304 of the second doping layer toward the first doping layer 200, that is, extends from a partial region of the strip-shaped portion 301 of the second doping layer toward the strip-shaped portion 201 of the first doping layer.

[0056] It should be noted that the extension portion 203 of the first doping layer is usually formed integrally with the main body portion 204 of the first doping layer, that is, extends from a partial region of the main body portion 204 of the first doping layer toward the second doping layer 300. However, the extension portion 203 of the first doping layer may also be formed separately from the main body portion 204 of the first doping layer, that is, by using an additional process, independently of the main body portion 204 of the first doping layer, to form a conductive block, where the conductive block is structurally connected or partially stacked with the main body portion 204 of the first doping layer, and may be the same or different in material and the same or different in conduction type. The extension portion 303 of the second doping layer is similar to the extension portion 203 of the first doping layer and will not be elaborated here.

[0057] Thus, in the above description, the first portion 351 of the second doping layer overlaps above a portion of the first doping layer 200 to form a stacked structure 600. The "first portion of the second doping layer" may be a part of the main body 304 of the second doping layer, or may be all or a part of the extension 303 of the second doping layer. The "portion of the first doping layer" may be a part of the main body 204 of the first doping layer, or may be all or a part of the extension 203 of the first doping layer. The "second portion of the second doping layer" depends on the "first portion of the second doping layer". Among them, when the first portion 351 of the second doping layer is a part of the main body 304 of the second doping layer, the second portion 352 of the second doping layer is a part of the main body 304 of the second doping layer. When the first portion 351 of the second doping layer is a part of the extension 303 of the second doping layer, the second portion 352 of the second doping layer is also a part of the extension 303 of the second doping layer.

[0058] Regarding the specific structure of the spacer region 190, in the back-contact battery 100 of the embodiment of the present application, the spacer region 190 may be a spacer region where the main body 204 of the first doping layer and the main body 304 of the second doping layer are disconnected.

[0059] Regarding the positions of the first doping layer 200 and the second doping layer 300 relative to the semiconductor substrate 101, the first doping layer 200 and the second doping layer 300 may both be formed within the semiconductor substrate 101. Alternatively, the first doping layer 200 and the second doping layer 300 may both be formed on the semiconductor substrate 101. Alternatively, the first doping layer 200 is formed within the semiconductor substrate 101, and the second doping layer 300 is formed on the semiconductor substrate 101. In the above several cases, the first portion 351 of the second doping layer 300 may overlap above a portion of the first doping layer 200 to form a stacked structure 600. Among them, when the first doping layer 200 is formed within the semiconductor substrate 101 and the second doping layer 300 is formed on the semiconductor substrate 101, generally the height of the main body 204 of the first doping layer 200 is higher than the height of the main body 304 of the second doping layer 300, and all or a part of the extension 303 of the second doping layer is used to overlap above a portion of the first doping layer 200 to form a stacked structure 600.

[0060] The formation position of the stacked structure 600 may be in the spacing region 190, the first doping region 191, and the second doping region 192. Specifically, when the stacked structure 600 is formed in the spacing region 190, all or part of the extension portion 303 of the second doping layer is overlapped on all or part of the extension portion 203 of the first doping layer; when the stacked structure 600 is formed in the first doping region 191, all or part of the extension portion 303 of the second doping layer is overlapped on part of the strip portion 201 of the first doping layer; when the stacked structure 600 is formed in the second doping region 192, part of the strip portion 301 of the second doping layer is overlapped on all or part of the extension portion 203 of the first doping layer.

[0061] For example, Figure 8 In the figure, at mark 801, the stacked structure 600 is formed at the spacing region 190, where the extension portion 303 of the second doping layer overlaps over the extension portion 203 of the first doping layer; at mark 802, the stacked structure 600 is formed at the first doping region 191, where the extension portion 303 of the second doping layer overlaps over a portion of the strip portion 201 of the first doping layer; at mark 803, the stacked structure 600 is formed at the second doping region 192, where a portion of the strip portion 301 of the second doping layer overlaps over the extension portion 203 of the first doping layer.

[0062] In some embodiments, Figure 5 As shown, the second doping layer 300 further includes an extension portion 303 of the second doping layer, the extension portion 303 of the second doping layer extends across the spacing region 190 and extends over a portion of the first doping layer 200 to form a stacked structure 600, wherein the first portion 351 and the second portion 352 of the second doping layer 300 are part of the extension portion 303 of the second doping layer. Figure 5 , the extension 303 of the second doping layer is shown to extend across the spacing region 190 and over a portion of the main portion 204 of the first doping layer. In this case, the second portion 352 of the second doping layer 300 near the stacked structure 600 is the extension 303 of the second doping layer. Figure 5 The second portion 352 of the second doping layer 300 is lifted upward to overlap the main portion 204 of the first doping layer, so that a part of the second portion 352 is tilted away from the stacked structure 600 to form a tilted portion 361.

[0063] Combination Figure 1 and Figure 5In this case, the extension portion 303 of the second doping layer can be roughly divided into three parts. The first part 351 is the part of the extension portion 303 of the second doping layer that forms the stacked structure 600. The third part 353 is the part of the extension portion 303 of the second doping layer that adheres to the semiconductor substrate 101. The second part 352 is the bridging part of the extension portion 303 of the second doping layer between the first part 351 and the third part 353. Among them, a part of the second part 352 warps away from the stacked structure 600 to form a warping portion 361. Figure 11 The SEM image of the back contact battery 100 with the warping portion 361 is shown.

[0064] It can be understood that for the three parts, namely the first part 351, the second part 352, and the third part 353 of the extension portion 303 of the second doping layer, they can be formed integrally, or each part can be formed separately. Two adjacent parts are electrically connected, connected in structure or partially stacked, and can be the same or different in material and the same in conduction type.

[0065] In some other embodiments, as Figure 4 shown, the first doping layer 200 further includes an extension portion 203 of the first doping layer, and the second doping layer 300 further includes an extension portion 303 of the second doping layer. The extension portion 303 of the second doping layer overlaps above the extension portion 203 of the first doping layer in the spacer region 190 to form a stacked structure 600. Among them, the first part 351 and the second part 352 of the second doping layer 300 are part of the extension portion 303 of the second doping layer. Specifically, the first part 351 of the second doping layer 300 is the part of the extension portion 303 of the second doping layer that forms the stacked structure 600, and the second part 352 is the bridging part of the extension portion 303 of the second doping layer close to the first part 151.

[0066] In still some other embodiments, as Figure 6 shown, the first doping layer 200 further includes an extension portion 203 of the first doping layer. The extension portion 203 of the first doping layer extends across the spacer region 190 and extends below the main body portion 304 of the second doping layer to form a stacked structure 600. Among them, the first part 351 of the second doping layer 300 is part of the main body portion 304 of the second doping layer. In Figure 6 it, the extension of the extension portion 203 of the first doping layer across the spacer region 190 and extending below the main body portion 304 of the second doping layer is shown. In this case, the second part 352 of the second doping layer 300 close to the stacked structure 600 is the part of the main body portion 304 of the second doping layer at Figure 6The portion between the dashed line and the multiple side docking surfaces 400. The second portion 352 of the second doping layer 300 is lifted upward because the end of the extension portion 203 of the first doping layer is inserted under the first portion 351 of the second doping layer 300, such that a part of the second portion 352 warps away from the stacked structure 600 to form a warped portion 361.

[0067] Figure 6 In [the structure shown in], the main body portion 304 of the second doping layer can be roughly divided into three parts. The first part 351 is the part of the main body portion 304 of the second doping layer that forms the stacked structure 600. The third part 353 is the part of the main body portion 304 of the second doping layer that adheres to the semiconductor substrate 101. The second part 352 is the bridging part of the main body portion 304 of the second doping layer between the first part 351 and the third part 353. Among them, a part of the second part 352 warps away from the stacked structure 600 to form a warped portion 361. For the first part 351, the second part 352, and the third part 353 of the main body portion 304 of the second doping layer, similar to the first part 351, the second part 352, and the third part 353 of the extension portion 303 of the second doping layer, they can be integrally formed or separately formed, which will not be elaborated here.

[0068] In some embodiments, in the back-contact battery 100 of the embodiment of the present application, another part of the second portion 352 of the second doping layer 300 closely adheres to the stacked structure 600 to form an adhering portion 362. Among them, in the first direction, multiple warped portions 361 and multiple adhering portions 362 are alternating; the first direction is parallel to the extending direction of the side surface of the first doping layer 200 in the stacked structure 600 that faces the second portion 352 of the second doping layer 300. By making the multiple warped portions 361 and the multiple adhering portions 362 alternate, it is possible to further ensure that the leakage points are dispersed and avoid local overheating; the existence of the adhering portion 362 can increase the proportion of the leakage contact area. Thus, by adjusting the total number of settings, the size, the arrangement manner, etc. of the multiple warped portions 361 and the multiple adhering portions 362, a balance can be achieved between improving the hot-spot effect and ensuring the photoelectric conversion efficiency.

[0069] The “first direction” is parallel to the extension direction of the side surface of the first doped layer 200 in the stacked structure 600 that is opposite to the second portion 352 of the second doped layer 300. In the back contact cell 100 of the embodiment of the present application, the first doped layer 200 and the second portion 352 of the second doped layer 300 in the stacked structure 600 are electrically connected, and the side surface of the first doped layer 200 in the stacked structure 600 that is opposite to the second portion 352 of the second doped layer 300 forms a side butt joint 400. The extension direction of the side surface of the first doped layer 200 in the stacked structure 600 that is opposite to the second portion 352 of the second doped layer 300 is also the extension direction of the side butt joint 400. Figure 3 a) shows the bending structure 500 of the side butt joint surface 400 in a top view. Figure 3 b) shows a side view of a plurality of raised portions 361 and a plurality of abutment portions 362 alternating in the first direction. Figure 5 In the example shown, there is a side butt joint surface 400. In this case, the extension direction of the side butt joint surface 400 and the corresponding first direction are Figure 5 The up and down direction; Figure 6 In the example shown, there are three side butt joint surfaces 400, each of which has its own extension direction and first direction. The extension direction of the first side butt joint surface 401 and the second side butt joint surface 402 and the corresponding first direction are specifically Figure 6 The left and right directions, and the extension direction of the third side docking surface 403 located in the middle, and the corresponding first direction are specifically Figure 6 Up and down direction.

[0070] The formation position of the side butt joint 400 is different according to the formation position of the stacked structure 600, and can be formed in the spacing region 190, the first doping region 191, the second doping region 192, the junction of the spacing region 190 and the first doping region 191, and the junction of the spacing region 190 and the second doping region 192. Specifically, when the stacked structure 600 is formed in the spacing region 190, the side butt joint 400 can be formed in the spacing region 190, the junction of the spacing region 190 and the first doping region 191, and the junction of the spacing region 190 and the second doping region 192; when the stacked structure 600 is formed in the first doping region 191, the side butt joint 400 can be formed in the first doping region 191, the spacing region 190 and the first doping region 191; when the stacked structure 600 is formed in the second doping region 192, the side butt joint 400 can be formed in the second doping region 192, the spacing region 190 and the second doping region 192.

[0071] Regarding the contact method between a part of the first doping layer 200 and a part of the second doping layer 300, a direct contact can be formed between a part of the first doping layer 200 and a part of the second doping layer 300 to form a side docking surface 400; an indirect contact can also be formed between a part of the first doping layer 200 and a part of the second doping layer 300 to form a side docking surface 400, that is, other layer structures may be provided between a part of the first doping layer 200 and a part of the second doping layer 300 as needed, as long as an electrical docking can be formed between a part of the first doping layer 200 and a part of the second doping layer 300.

[0072] In some embodiments, in the back-contact battery 100 of the embodiment of the present invention, the side docking surface 400 has a bent structure 500. In other words, the side docking surface 400 is not a flat surface. When there are multiple side docking surfaces, one or more of them may have a bent structure 500. Compared with the docking surface of a planar structure, the side docking surface 400 with a bent structure 500 can increase the leakage channel contact area of a single side docking surface 400, effectively reduce the total number of anti-thermal-spot structures provided, and minimize the loss of battery conversion efficiency caused by PN junction contact while improving the thermal-spot effect.

[0073] Specifically, in the direction parallel to the backlight surface 112, a single side docking surface 400 has a bent unfolded length L (not shown in the figure) and an end straight length D (see Figure 10 ), where L > 1.001D. By defining the relationship between the bent unfolded length L and the end straight length D as L > 1.001D, it can be ensured that the side docking surface 400 forms a bend.

[0074] In some embodiments, under the measurement condition of a 10-micron step size, L ≥ 1.05D. For example, L is 1.05D, 1.08D, 1.10D, 1.20D. By setting L ≥ 1.05D, it can be further ensured that the side docking surface 400 has a bent structure. Considering that in practical applications, it may be difficult or too complex to measure a complete side docking surface 400, the size relationship between L and D can be determined under the measurement condition of a 10-micron step size. The measurement condition of a 10-micron step size is to select one or more local segments with a 10-micron straight length from the entire side docking surface 400. The end straight length D of the one or more local segments is 10 microns, and the bent unfolded length L of the bent structure of the one or more local segments is measured, and thus the size relationship between L and D is directly obtained or obtained by averaging.

[0075] In a preferred embodiment, under the measurement condition of a 1-μm step size, L ≥ 1.2D. For example, L is 1.2D, 1.4D, 1.5D, 1.8D, 5D. By setting L ≥ 1.2D, it can be ensured that the bent structure of the side docking surface 400 can greatly increase the leakage channel contact area of a single side docking surface 400, effectively prevent the back contact battery 100 from being burned due to local heat concentration, effectively reduce the hot spot risk of the back contact battery 100 and the photovoltaic module including the back contact battery 100, and at the same time can also effectively reduce the total number of side docking surfaces 400 provided. Generally, L ≤ 800D. For example, L is 800D, 600D, 200D, 50D, 10D. When L exceeds the foregoing range, the etching difficulty will be too great, affecting the production efficiency.

[0076] The value range of D can be 10 - 3000 μm. D is, for example, 10 μm, 100 μm, 500 μm, 1000 μm, 1500 μm, 2500 μm, 3000 μm.

[0077] The value range of L can be 50 - 8000 μm. L is, for example, 50 μm, 150 μm, 650 μm, 1500 μm, 2500 μm, 3000 μm, 5000 μm, 8000 μm.

[0078] For the "direction parallel to the backlight surface", taking the case where the backlight surface 112 of the semiconductor substrate 101 is on the upward side as an example, for example Figure 7 in the upper part, the direction of the backlight surface 112 can be considered as a generally horizontal direction. The side docking surface 400 is a surface perpendicular to the horizontal direction or having a certain angle with the horizontal direction. This surface has two first vertical sides perpendicular to the horizontal direction or having a certain angle with the horizontal direction, and two second horizontal sides generally parallel to the horizontal direction. In this article, the "direction parallel to the backlight surface 112" refers to the extension direction of the second horizontal side, which is also called the "extension direction of the side docking surface" and the "extension direction of the bent structure". Thus, the bent unfolded length L and the end straight length D are respectively the bent unfolded length and the end straight length of the second horizontal side. For example, in Figure 6 the example shown, there are three side docking surfaces 400. Each side docking surface 400 has its own direction parallel to the backlight surface 112, its own extension direction of the side docking surface 400, and its own extension direction of the bent structure 500. Among them, the direction parallel to the backlight surface 112, the extension direction of the side docking surface, and the extension direction of the bent structure 500 of the first side docking surface 401 and the second side docking surface 402 are specifically Figure 6 the left - right direction, while the direction parallel to the backlight surface 112, the extension direction of the side docking surface, and the extension direction of the bent structure 500 of the third side docking surface 403 are specifically Figure 6Up and down direction.

[0079] The bending structure 500 may be any structure that can make the side butt joint surface 400 no longer a flat surface. The exemplary structure of the bending structure 500 is described in detail below in conjunction with the accompanying drawings.

[0080] In some embodiments, the bending structure 500 includes a plurality of connecting sections 510 connected in a bending manner in a direction parallel to the backlight surface 112, such as Figure 3 a) and Figure 10 By configuring the bending structure 500 to include a plurality of docking sections 510 connected in a bent manner, it can be ensured that the presence of the bending structure 500 can greatly increase the contact area of ​​the leakage channel of a single side docking surface 400, effectively prevent local overheating of the back contact battery 100, and effectively reduce the total number of side docking surfaces 400.

[0081] Continue to refer Figure 3 a) and Figure 10 In the docking section 510, there are a plurality of protruding portions 511 protruding toward the second portion 352 of the second doping layer 300, and a plurality of recessed portions 512 recessed away from the second portion 352 of the second doping layer 300. In some embodiments, the raised portion 361 may be formed at a position of the second portion 352 of the second doping layer 300 corresponding to the protruding portion 511, such as Figure 3 or, the raised portion 361 may be formed at a position corresponding to the recessed portion 512 of the second portion 352 of the second doping layer 300, such as Figure 3 or, the raised portion 361 may be formed at a position of the second portion 352 of the second doping layer 300 corresponding to the recessed portion 512 adjacent to the protruding portion 511, such as Figure 3 By making the position of the raised portion 361 correspond to the protruding portion 511, the recessed portion 512, and the recessed portion 512 adjacent to the protruding portion 511 of the docking section, it is ensured that the raised portion 361 is dispersed, and then the fitting portion 362 is dispersed, which is further conducive to the dispersion of the leakage points.

[0082] In some embodiments, an air gap 363 is defined between the raised portion 361, the first doped layer 200 in the stacked structure 600, and the semiconductor substrate 101. Figure 1As shown. The existence of the air gap 363 can separate a partial area of the first doped layer 200 in the stacked structure 600 from the second part 352 of the second doped layer 300, so that a leakage current area cannot be formed at the air gap 363, dispersing the leakage points and avoiding local overheating; a physical insulation can be formed through the air gap 363. Compared with a dielectric layer with certain conductivity (such as an interface passivation layer, etc.), the insulation effect of the air gap 363 is stronger and the reliability is higher, which can enhance the local insulation effect, further reduce the contact recombination, and is beneficial to the forward power generation of the back contact battery 100.

[0083] The back contact battery 100 further includes a surface passivation layer 140, and the surface passivation layer 140 covers the first doped layer 200, the second doped layer 300, and the stacked structure 600. Among them, the surface passivation layer 140 extends into the air gap 363 at the upturned part 361, so as to fill part or all of the air gap 363, such as Figure 4 shown. Figure 4 The surface passivation layer 140 is shown in, where the surface passivation layer 140 extends into the air gap 363 at the upturned part 361, so as to fill part of the air gap 363. In the case where the surface passivation layer 140 fills part of the air gap 363, not only the air gap 363 is used for insulation at the upturned part 361, but also the surface passivation layer 140 is used for separation, which is beneficial to the forward power generation of the back contact battery 100.

[0084] The following combines Figure 9 to illustrate the back contact battery 100 of the embodiment of the present application.

[0085] In Figure 9 , the first doped layer 200 includes the main body 204 of the first doped layer, and the second doped layer 300 includes the main body 304 of the second doped layer. The main body 204 of the first doped layer and the main body 304 of the second doped layer are alternately distributed in an interdigitated manner at intervals. There is an interval area 190 between the main body 204 of the first doped layer and the main body 304 of the second doped layer. Specifically, Figure 9In it, the main body portion 204 of the first doping layer includes the strip-shaped portion 201 of the first doping layer and the connecting portion 202 of the first doping layer. Among them, the connecting portion 202 of the first doping layer is used to connect a plurality of strip-shaped portions 201 of the first doping layer. The second doping layer 300 includes the strip-shaped portion 301 of the second doping layer and the connecting portion 302 of the second doping layer. Among them, the connecting portion 302 of the second doping layer is used to connect a plurality of strip-shaped portions 301 of the second doping layer. The region where the strip-shaped portion 201 of the first doping layer is located is the first doping region 191, the region where the strip-shaped portion 301 of the second doping layer is located is the second doping region 192, the region where the connecting portion 202 of the first doping layer is located is the third doping region 193, and the region where the connecting portion 302 of the second doping layer is located is the fourth doping region 194. In this case, the spacer region 190 can be formed between the strip-shaped portion 201 of the first doping layer and the adjacent strip-shaped portion 301 of the second doping layer, that is, between the first doping region 191 and the second doping region 192; formed between the strip-shaped portion 201 of the first doping layer and the adjacent connecting portion 302 of the second doping layer, that is, between the first doping region 191 and the fourth doping region 194; formed between the connecting portion 202 of the first doping layer and the adjacent strip-shaped portion 301 of the second doping layer, that is, between the third doping region 193 and the second doping region 192.

[0086] The first doping layer 200 may further include an extension portion 203 of the first doping layer. The extension portion 203 of the first doping layer extends from a partial region of the main body portion 204 of the first doping layer toward the second doping layer 300, that is, extends from the strip-shaped portion 201 of the first doping layer or the connecting portion 202 of the first doping layer toward the second doping layer 300. Specifically, the extension portion 203 of the first doping layer extends from a partial region of the strip-shaped portion 201 of the first doping layer toward the strip-shaped portion 301 or the connecting portion 302 of the second doping layer, or extends from all or a partial region of the connecting portion 202 of the first doping layer toward the strip-shaped portion 301 of the second doping layer.

[0087] The second doping layer 300 may further include an extension portion 303 of the second doping layer. The extension portion 303 of the second doping layer extends from a partial region of the main body portion 304 of the second doping layer toward the first doping layer 200, that is, extends from the strip-shaped portion 301 of the second doping layer or the connecting portion 302 of the second doping layer toward the first doping layer 200. Specifically, the extension portion 303 of the second doping layer extends from a partial region of the strip-shaped portion 301 of the second doping layer toward the strip-shaped portion 201 or the connecting portion 202 of the first doping layer, or extends from all or a partial region of the connecting portion 302 of the second doping layer toward the strip-shaped portion 201 of the first doping layer.

[0088] Similar to Figure 8 Similar,Figure 9 The extension portion 203 of the first doping layer in Figure 9 is usually formed integrally with the main body portion 204 of the first doping layer. However, the extension portion 203 of the first doping layer can also be formed separately from the main body portion 204 of the first doping layer. The extension portion 303 of the second doping layer is similar to the extension portion 203 of the first doping layer and will not be elaborated here.

[0089] Thus, in the stacked structure 600 formed by overlapping a first part 351 of the foregoing second doping layer over a part of the first doping layer 200, the "first part of the second doping layer" can be a part of the strip-shaped portion 301 of the second doping layer, or all or part of the connecting portion 302 of the second doping layer, or all or part of the extension portion 303 of the second doping layer; the "part of the first doping layer" can be a part of the strip-shaped portion 201 of the first doping layer, or all or part of the connecting portion 202 of the first doping layer, or all or part of the extension portion 203 of the first doping layer; the "second part of the second doping layer" depends on the "first part of the second doping layer". Among them, when the first part 351 of the second doping layer is a part of the main body portion 304 of the second doping layer, the second part 352 of the second doping layer is a part of the main body portion 304 of the second doping layer; when the first part 351 of the second doping layer is a part of the connecting portion 302 of the second doping layer, the second part 352 of the second doping layer is a part of the connecting portion 302 of the second doping layer; when the first part 351 of the second doping layer is a part of the extension portion 303 of the second doping layer, the second part 352 of the second doping layer is also a part of the extension portion 303 of the second doping layer. It should be understood that usually a part of the second doping layer 300 overlaps over a part of the first doping layer 200 in the adjacent position to form the stacked structure 600.

[0090] For the formation position of the stacked structure 600, it can be in the spacer region 190, the first doped region 191, the second doped region 192, the third doped region 193, and the fourth doped region 194. Specifically, when the stacked structure 600 is formed in the spacer region 190, all or a part of the extension portion 303 of the second doped layer overlaps above all or a part of the extension portion 203 of the first doped layer; when the stacked structure 600 is formed in the first doped region 191, all or a part of the extension portion 303 of the second doped layer overlaps above a part of the strip portion 201 of the first doped layer; when the stacked structure 600 is formed in the second doped region 192, a part of the strip portion 301 of the second doped layer overlaps above all or a part of the extension portion 203 of the first doped layer; when the stacked structure 600 is formed in the third doped region 193, all or a part of the extension portion 303 of the second doped layer overlaps above all or a part of the connection portion 202 of the first doped layer; when the stacked structure 600 is formed in the fourth doped region 194, all or a part of the connection portion 302 of the second doped layer overlaps above all or a part of the extension portion 203 of the first doped layer.

[0091] For example, Figure 9 in, at the mark 901, the stacked structure 600 can be at the spacer region 190, and the extension portion 303 of the second doped layer (the extension portion 303 of the second doped layer is specifically formed by extending from the strip portion 301 of the second doped layer toward the connection portion 202 of the first doped layer) overlaps above the extension portion 203 of the first doped layer (the extension portion 203 of the first doped layer is specifically formed by extending from the connection portion 202 of the first doped layer toward the strip portion 301 of the second doped layer); at the mark 902, the stacked structure 600 can be at the first doped region 191, and the extension portion 303 of the second doped layer (the extension portion 303 of the second doped layer is specifically formed by extending from the strip portion 301 of the second doped layer toward the strip portion 201 of the first doped layer) overlaps above a part of the strip portion 201 of the first doped layer; at the mark 903, the stacked structure 600 can be at the first doped region 191, and the extension portion 303 of the second doped layer (the extension portion 303 of the second doped layer is specifically formed by extending from the connection portion 302 of the second doped layer toward the strip portion 201 of the first doped layer) overlaps above a part of the strip portion 201 of the first doped layer.

[0092] For the specific structure of the spacer region 190, the formation method of the stacked structure 600, the formation position of the side docking surface 400, the positions of the first doped layer 200 and the second doped layer 300 relative to the semiconductor substrate 101, the contact method between a part of the first doped layer 200 and a part of the second doped layer 300, etc. Figure 8The back contact cell 100 in FIG. 1 is similar in part, and only some features are shown below.

[0093] In some embodiments, another part of the second portion 352 of the second doping layer 300 is in close contact with the stacked structure 600 to form a contact portion 362; wherein, in a first direction, a plurality of raised portions 361 and a plurality of contact portions 362 are alternated; and the first direction is parallel to the extension direction of the side surface of the first doping layer 200 in the stacked structure 600 that is opposite to the second portion 352 of the second doping layer 300. The effect is similar to the above, and will not be described in detail here.

[0094] In some embodiments, the first doped layer 200 and the second portion 352 of the second doped layer 300 in the stacked structure 600 are electrically connected, and the side surface of the first doped layer 200 in the stacked structure 600 opposite to the second portion 352 of the second doped layer 300 forms a side interface 400, wherein the side interface 400 has a bent structure 500. The effect is similar to the above, and will not be repeated here.

[0095] As for the formation position of the side docking surface 400, similar to the foregoing, it can be at the spacing region 190, the first doping region 191, the second doping region 192, the third doping region 193, the fourth doping region 194, the junction of the spacing region 190 and the first doping region 191 (which can also be called the junction of the spacing region 190 and the strip portion 201 of the first doping layer), the junction of the spacing region 190 and the second doping region 192 (which can also be called the junction of the spacing region 190 and the strip portion 301 of the second doping layer), the junction of the spacing region 190 and the third doping region 193 (which can also be called the junction of the spacing region 190 and the extension 203 of the first doping layer), the junction of the spacing region 190 and the fourth doping region 194 (which can also be called the junction of the spacing region 190 and the connecting portion 302 of the second doping layer), etc., which will not be elaborated here.

[0096] In some embodiments, an air gap 363 is defined between the raised portion 361, the first doped layer 200 in the stacked structure 600, and the semiconductor substrate 101. The effect is similar to the above, and will not be described in detail here.

[0097] In some embodiments, the back contact cell 100 further includes a surface passivation layer 140, which covers the first doping layer 200, the second doping layer 300 and the stacked structure 600, wherein the surface passivation layer 140 extends into the air gap 363 at the raised portion 361, thereby filling part or all of the air gap 363. The effect is similar to the above, and will not be repeated here.

[0098] Combine the following Figure 7 , the overall structure of the back contact battery 100 of an embodiment of the present application is described.

[0099] like Figure 7 As shown, the back contact cell 100 comprises: a semiconductor substrate 101, a first doping layer 200 and a second doping layer 300; the main body 204 of the first doping layer and the main body 304 of the second doping layer are alternately distributed on the backlight side of the semiconductor substrate 101, and the first doping layer 200 and the second doping layer 300 have opposite conductivity types; wherein the first portion 351 of the second doping layer 300 overlaps a portion of the first doping layer 200 to form a stacked structure 600; and wherein a portion of the second portion 352 of the second doping layer 300 close to the stacked structure 600 is tilted away from the stacked structure 600 to form a tilted portion 361. Specifically, the extension portion 303 of the second doping layer extends across the spacing region and extends above the main body 204 of the first doping layer to form the stacked structure 600; and wherein a portion of the second portion 352 of the extension portion 303 of the second doping layer close to the stacked structure 600 is tilted away from the stacked structure 600 to form a tilted portion 361. The surface passivation layer 140 covers the first doping layer 200 , the second doping layer 300 and the stacked structure 600 , wherein the surface passivation layer 140 extends into the air gap 363 at the raised portion 361 , thereby filling the entire air gap 363 .

[0100] Figure 7 The back contact battery 100 shown may also include a first dielectric layer 131 located between the first doping layer 200 and the semiconductor substrate 101, a second dielectric layer 132 located between the second doping layer 300 and the semiconductor substrate 101, an insulating layer 150 located between the extension portion 303 of the second doping layer in the stacked structure 600 and the main portion 204 of the first doping layer, a first electrode 121, and a second electrode 122.

[0101] It should be noted that, in terms of the specific electrode structure of the positive electrode and the negative electrode, the back contact battery 100 of the embodiment of the present invention may be a "back contact battery without a main grid". In this case, the electrode structure in the back contact battery only includes a plurality of collector electrodes (a first electrode 121 and a second electrode 122). The collector electrodes may also be referred to as fine grid lines. The plurality of collector electrodes may extend along a first direction and be spaced apart along a second direction. Alternatively, the back contact battery 100 of the embodiment of the present invention may also be a "back contact battery with a main grid. In this case, the back contact battery includes a plurality of collector electrodes and a plurality of bus structures (not shown in the figure). The bus structures may also be referred to as bus electrodes. The bus structures are spaced apart along a first direction and extend along a second direction, and are electrically coupled to collector electrodes of the same conductivity type as themselves. The bus structure may be a structure extending over the entire cell or a structure extending over only a portion of the cell.

[0102] The materials of each layer and electrode of the back-contact battery 100 in the embodiments of the present invention, etc. can refer to any materials that can be used to prepare the back-contact battery 100 in the prior art. The materials of each layer, etc. are briefly described below.

[0103] The semiconductor substrate can be a silicon substrate. The silicon substrate can be N-type or P-type silicon, with a thickness of 30 - 500 microns. The backlight surface and the light-facing surface of the semiconductor substrate can be flat. Alternatively, the light-facing surface of the semiconductor substrate can also be a textured surface.

[0104] The conductivity type of the first doping layer can be N-type, in which case the conductivity type of the second doping layer is P-type; or, the conductivity type of the first doping layer can also be P-type, in which case the conductivity type of the second doping layer is N-type. For the specific materials of the first doping layer and the second doping layer, the N-type doping layer can be one or more of single-crystalline silicon, polycrystalline silicon, amorphous silicon, microcrystalline silicon, nanocrystalline silicon, and silicon oxide, and its N-type doping element can be one or more of carbon, nitrogen, phosphorus, arsenic, antimony, bismuth, oxygen, sulfur, selenium, and tellurium; the P-type doped semiconductor layer can be one or more of single-crystalline silicon, polycrystalline silicon, amorphous silicon, microcrystalline silicon, nanocrystalline silicon, and silicon oxide, and its P-type doping element can be one or more of boron, aluminum, gallium, indium, thallium, carbon, and nitrogen. The thicknesses of the first doping layer and the second doping layer can be set as needed, for example, 3 - 3000 nm.

[0105] The first dielectric layer and the second dielectric layer can be one or more of oxides, nitrides, oxynitrides, halides, carbides, and silicon, and their thicknesses can be set as needed, for example, 0 - 10 nm. Preferably, the dielectric layer, the first dielectric layer, and the second dielectric layer can be one or more of silicon oxide, aluminum oxide, titanium oxide, niobium oxide, boron oxide, gallium oxide, tin oxide, hafnium oxide, tantalum oxide, silicon nitride, oxynitride silicon, silicon carbide, lithium fluoride, magnesium fluoride, amorphous silicon, microcrystalline silicon, nanocrystalline silicon, etc.

[0106] The insulating layer can be one or more of oxides, nitrides, oxynitrides, halides, carbides, and silicon, and its thickness can be set as needed, for example, 0 - 5000 nm. Preferably, the insulating layer can be one or more of phosphosilicate glass, borosilicate glass, aluminosilicate glass, gallium silicate glass, silicon oxide, aluminum oxide, silicon nitride, oxynitride silicon, silicon carbide, and amorphous silicon, etc.

[0107] The surface passivation layer can be one or more of oxides, nitrides, oxynitrides, halides, carbides, and silicon, and its thickness can be set as needed, for example, 0 - 1000 nm. Preferably, the surface passivation layer can be one or more of silicon oxide, aluminum oxide, titanium oxide, niobium oxide, boron oxide, gallium oxide, tin oxide, hafnium oxide, tantalum oxide, indium oxide, tungsten oxide, zinc oxide, silicon nitride, oxynitride silicon, silicon carbide, lithium fluoride, magnesium fluoride, amorphous silicon, microcrystalline silicon, nanocrystalline silicon, etc.

[0108] The preparation method of the back-contact battery 100 according to the embodiment of the present invention may refer to any method that can be used to prepare the back-contact battery 100 in the prior art, and will not be limited herein. For the formation of the warped portion, it can be prepared by adjusting processes such as temperature and other conditions during the battery preparation process, or it can be achieved by pre-embedding a film layer. For example, a suitable additional film layer is pre-embedded between a partial region of the first doping layer and the second portion of the second doping layer in the stacked structure, and then all or part of the film layer is ablated to obtain the warped portion.

[0109] Unless there are technical obstacles or contradictions, the various technical features disclosed in this application can be freely combined to form additional embodiments, and these additional embodiments are all within the protection scope of this application.

[0110] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "one example", "some examples", or "preferred embodiment" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0111] The embodiments of the present invention have been described in detail above. However, the aspects of the present invention are not limited to the above embodiments. Without departing from the scope of the present invention, various modifications and substitutions can be applied to the above embodiments.

Claims

1. A back contact battery, wherein: The back contact cell comprises: a semiconductor substrate, a first doping layer and a second doping layer; The main body of the first doping layer and the main body of the second doping layer are alternately distributed on the backlight side of the semiconductor substrate, and the first doping layer and the second doping layer have opposite conductivity types; The first portion of the second doped layer overlaps a portion of the first doped layer to form a stacked structure; and a portion of the second portion of the second doped layer close to the stacked structure is tilted away from the stacked structure to form a tilted portion.

2. The back contact cell according to claim 1, wherein: Another part of the second portion of the second doping layer is in close contact with the stacked structure to form a contact portion; Wherein, in a first direction, a plurality of the raised portions and a plurality of the bonding portions are alternated; and the first direction is parallel to an extension direction of a side surface of the first doped layer in the stacked structure that is opposite to the second portion of the second doped layer.

3. The back contact cell according to claim 1, wherein: The first doped layer and the second part of the second doped layer in the stacked structure are electrically connected, and the side of the first doped layer in the stacked structure opposite to the second part of the second doped layer forms a side butt surface, wherein the side butt surface has a bending structure.

4. The back contact cell according to claim 3, wherein: The bending structure includes a plurality of connecting sections connected in a bending manner in a direction parallel to the backlight surface.

5. The back contact cell according to claim 4, wherein: There are a plurality of protruding portions protruding toward the second portion of the second doping layer and a plurality of recessed portions recessed away from the second portion of the second doping layer in the butting section.

6. The back contact cell according to claim 5, wherein: The raised portion is formed at a position of the second portion of the second doping layer corresponding to the protruding portion; or The raised portion is formed at a position of the second portion of the second doping layer corresponding to the recessed portion; or The raised portion is formed at a position of the second portion of the second doping layer corresponding to the recessed portion adjacent to the protruding portion.

7. The back contact cell according to claim 1, wherein: An air gap is defined between the raised portion, the first doped layer in the stacked structure, and the semiconductor substrate.

8. The back contact cell according to claim 7, wherein: The back contact battery also includes a surface passivation layer, which covers the first doping layer, the second doping layer and the stacked structure, wherein the surface passivation layer extends into the air gap at the raised portion, thereby filling part or all of the air gap.

9. The back contact cell according to claim 1, wherein: A spacing region is provided between the main body portion of the first doping layer and the main body portion of the second doping layer; The second doping layer also includes an extension of the second doping layer, which extends across the spacing region and extends over a portion of the first doping layer to form the stacked structure, wherein the first and second portions of the second doping layer are portions of the extension of the second doping layer.

10. The back contact cell according to claim 1, wherein: A spacing region is provided between the main body portion of the first doping layer and the main body portion of the second doping layer; The first doping layer also includes an extension of the first doping layer, and the second doping layer also includes an extension of the second doping layer, and the extension of the second doping layer overlaps the extension of the first doping layer in the spacing area to form the stacked structure, wherein the first part and the second part of the second doping layer are part of the extension of the second doping layer.

11. The back contact cell according to claim 1, wherein: A spacing region is provided between the main body portion of the first doping layer and the main body portion of the second doping layer; The first doping layer also includes an extension portion of the first doping layer, which extends across the spacing region and extends below the main portion of the second doping layer to form the stacked structure, wherein the first portion of the second doping layer is a portion of the main portion of the second doping layer.

12. A photovoltaic module, wherein: The photovoltaic module comprises: A battery string, the battery string being formed by electrically connecting a plurality of back-contact batteries according to any one of claims 1 to 11; and A packaging layer covers a surface of the battery string.

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