Back contact solar cell and photovoltaic module

Abstract

The utility model relates to a back contact solar cell and a photovoltaic assembly. The back contact solar cell includes: a substrate including a first surface; the passivation contact layer is arranged on the first surface, the passivation contact layer comprises first doped regions and second doped regions, the first doped regions and the second doped regions are alternately arranged at intervals in the first direction, and the types of doping elements of the first doped regions and the second doped regions are opposite; the first electrode is arranged on the side, away from the substrate, of the first doped region and is in ohmic contact with the first doped region; wherein the first doped region comprises a plurality of first local passivation contact parts which are arranged at intervals in the second direction, and the first direction and the second direction intersect and are both parallel to the first surface. According to the back contact solar cell and the photovoltaic assembly, parasitic absorption can be reduced, and the efficiency of the back contact solar cell is high.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaics, in particular to a back contact solar cell and a photovoltaic component. Background Art

[0002] IBC (Interdigitated Back Contact) cells appeared in the 1970s. They set the positive and negative electrodes of the cell on the back of the cell, and there is no metal shading on the front, which greatly improves the optical absorption of the cell. With the continuous development of photovoltaic technology, the mainstream technology of back-contact solar cells in the industry currently combines the full back electrode structure and the passivation contact structure. However, the passivation contact layer has a more obvious absorption effect on photons, which causes the photons reaching the back of the back-contact solar cell to be absorbed by the passivation contact layer set on the back of the cell. The parasitic absorption is more obvious, which reduces the short-circuit current of the back-contact solar cell and affects the efficiency of the back-contact solar cell. Utility Model Content

[0003] Based on this, it is necessary to provide a back-contact solar cell and photovoltaic module that can reduce parasitic absorption and have higher efficiency.

[0004] A first aspect of an embodiment of the present application provides a back-contact solar cell, comprising:

[0005] a substrate, the substrate comprising a first surface;

[0006] a passivation contact layer, the passivation contact layer being disposed on the first surface, and comprising first doping regions and second doping regions arranged alternately and at intervals along a first direction, and the types of doping elements of the first doping regions and the second doping regions are opposite; and

[0007] A first electrode, the first electrode is disposed on a side of the first doping region facing away from the substrate and is in ohmic contact with the first doping region;

[0008] The first doped region includes a plurality of first local passivation contact portions spaced apart along a second direction, and the first direction and the second direction intersect and are both parallel to the first surface.

[0009] In one embodiment, the first electrode includes a plurality of first fine gates spaced apart along a first direction, each first fine gate extends along a second direction, and a plurality of first local passivation contacts of a first doping region are in ohmic contact with a corresponding first fine gate.

[0010] In one embodiment, the back-contact solar cell further includes a second electrode, the second electrode is disposed on a side of the second doping region away from the substrate, the second electrode includes a plurality of second fine grids spaced apart along the first direction, each second fine grid extending along the second direction;

[0011] The second doping region includes a plurality of second local passivation contacts arranged at intervals along the second direction, and the plurality of second local passivation contacts of one second doping region are in ohmic contact with the corresponding second fine gate.

[0012] In one embodiment, the first fine gate and the second fine gate are both configured as continuous strip structures extending along the second direction;

[0013] The first local passivation contact portions and the second local passivation contact portions are evenly distributed along the second direction.

[0014] In one embodiment, the first fine gate includes a plurality of first sub-gate lines arranged at intervals along the second direction, and the first local passivation contact portions corresponding to the first fine gate are multiple groups, and are in ohmic contact with the corresponding multiple first sub-gate lines group by group; and / or

[0015] The second fine gate includes a plurality of second sub-gate lines arranged at intervals along the second direction. The second fine gate corresponds to a plurality of second local passivation contact portions, which are in ohmic contact with the corresponding plurality of second sub-gate lines group by group.

[0016] In one embodiment, the back contact solar cell further comprises a passivation layer, the passivation layer is stacked and arranged on a side of the passivation contact layer away from the substrate, and the first electrode and the second electrode are arranged on the passivation layer;

[0017] The passivation layer is provided with a first through hole and a second through hole at positions corresponding to each first local passivation contact portion and each second local passivation contact portion;

[0018] Each first local passivation contact portion is in ohmic contact with the corresponding first fine grid through the first through hole; each second local passivation contact portion is in ohmic contact with the corresponding second fine grid through the second through hole.

[0019] In one embodiment, an outer contour shape of at least one of the first local passivation contact portion and the second local passivation contact portion is configured as a circle, a diamond, or a square.

[0020] In one embodiment, the spacing between adjacent first local passivation contacts is no greater than 1000 microns, the spacing between adjacent second local passivation contacts is no greater than 1000 microns, and the spacing between adjacent first local passivation contacts and second local passivation contacts is no greater than 1000 microns.

[0021] In one embodiment, the back-contact solar cell further includes a second electrode, the second electrode is disposed on a side of the second doping region away from the substrate, the second electrode includes a plurality of second fine grids spaced apart along the first direction, each second fine grid extending along the second direction;

[0022] The second doping region includes a plurality of second local passivation contacts arranged at intervals along the first direction. The second local passivation contacts are arranged in one-to-one correspondence with the first fine grids, and the projection of the second local passivation contact on the first surface covers the projection of the corresponding second fine grid on the first surface.

[0023] In a second aspect of the embodiments of the present application, a photovoltaic module is provided, which includes at least one battery string, and the battery string includes at least two of the above-mentioned back-contact solar cells.

[0024] Beneficial effects of the above-mentioned back-contact solar cell and photovoltaic module:

[0025] By making the first doping region include a plurality of first local passivation contacts arranged at intervals along the second direction, it is equivalent to setting a plurality of spaced first local passivation contacts in the region corresponding to the first doping region on the first surface. Compared with the solution of setting passivation contact materials on the entire first surface layer, the setting area of the passivation contact materials is reduced, and the absorption of incident light is reduced. Thus, the parasitic absorption on the first surface side of the back-contact solar cell can be reduced, the short-circuit current of the back-contact solar cell can be increased, and thus the efficiency of the back-contact solar cell can be improved.

[0026] In addition, since the first doping region includes a plurality of first local passivation contacts, the area of the first doping region can be changed by adjusting the size of a single first local passivation contact, so as to flexibly adjust the area ratio of the first doping region on the first surface. In other words, the overall area ratio of the first doping region can be configured as the optimal area ratio to make the efficiency of the solar cell reach the optimum. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of the back-contact solar cell provided by the embodiments of the present application;

[0028] Figure 2 is a schematic partial structural diagram of the back-contact solar cell provided by the embodiments of the present application;

[0029] Figure 3 is a schematic diagram of another structure of the back-contact solar cell provided by the embodiments of the present application;

[0030] Figure 4 is a schematic partial side cross-sectional view of the back-contact solar cell provided by the embodiments of the present application;

[0031] Figure 5 is a schematic diagram of still another structure of the back-contact solar cell provided by the embodiments of the present application;

[0032] Figure 6 is a schematic diagram of still another structure of the back-contact solar cell provided by the embodiments of the present application;

[0033] Figure 7 Schematic diagram of forming a first local passivation contact structure and a second local passivation contact structure in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application;

[0034] Figure 8 Schematic diagram of forming a passivation layer in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application;

[0035] Figure 9 Schematic diagram of forming a first through hole and a second through hole in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application;

[0036] Figure 10 Schematic diagram of forming a first electrode and a second electrode in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application;

[0037] Figure 11 Schematic diagram of forming a first local passivation contact structure and a second local passivation contact structure in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application;

[0038] Figure 12 Schematic diagram of forming a passivation layer in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application;

[0039] Figure 13 Schematic diagram of forming a first through hole in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application;

[0040] Figure 14 Schematic diagram of forming a contact groove on the passivation layer in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application;

[0041] Figure 15 Schematic diagram of forming a first electrode and a second electrode in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application;

[0042] Figure 16 Schematic diagram of forming a contact groove with another structure on the passivation layer in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application;

[0043] Figure 17 Schematic diagram of forming a first electrode and a second electrode in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application.

[0044] Explanation of the reference numerals in the drawings:

[0045] 100. Back-contact solar cell;

[0046] 10. Substrate;

[0047] 20. Passivation contact layer; 201. First doped region; 202. Second doped region; 21. First local passivation contact portion; 22. Second local passivation contact portion; 30. First electrode; 31. First fine grid; 311. First sub-grid line; 32. First main grid; 40. Passivation layer; 41. First through hole; 42. Second through hole; 43. Contact groove; 50. Second electrode; 51. Second fine grid; 511. Second sub-grid line; 52. Second main grid; 60. Insulating portion;

[0048] F. First surface; Y. First direction; E. Second direction. Detailed implementation manners

[0049] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the following will describe the detailed implementation manners of the present utility model with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present utility model. However, the present utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed below.

[0050] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present utility model.

[0051] In addition, 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 at least one of such features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0052] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "linkage", "fixation" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication between two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0053] In the present utility model, unless otherwise clearly defined and limited, the first feature may be in direct contact with the second feature or in indirect contact with the second feature through an intermediate medium when the first feature is "above" or "below" the second feature. Moreover, when the first feature is "above", "over" and "on top of" the second feature, the first feature may be directly above or obliquely above the second feature, or merely indicate that the horizontal height of the first feature is higher than that of the second feature. When the first feature is "under", "beneath" and "underneath" the second feature, the first feature may be directly below or obliquely below the second feature, or merely indicate that the horizontal height of the first feature is less than that of the second feature.

[0054] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "above", "below", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0055] The back-contact solar cell and photovoltaic module according to the embodiments of the present application will be described below with reference to the accompanying drawings.

[0056] Figure 1 is a schematic structural diagram of the back-contact solar cell provided by the embodiments of the present application; Figure 2 is a partial structural schematic diagram of the back-contact solar cell provided by the embodiments of the present application.

[0057] Refer to Figure 1 、 Figure 2 The back-contact solar cell 100 according to the embodiments of the present application includes a substrate 10, a passivation contact layer 20, and a first electrode 30.

[0058] The substrate 10 includes a first surface F. The passivation contact layer 20 is disposed on the first surface F, and the passivation contact layer 20 includes first doping regions 201 and second doping regions 202 that are alternately and spaced apart along a first direction Y, and the types of doping elements in the first doping regions 201 and the second doping regions 202 are opposite. The first electrode 30 is disposed on a side of the first doping region 201 away from the substrate 10, and is in ohmic contact with the first doping region 201.

[0059] The first doped region 201 includes a plurality of first local passivation contact portions 21 arranged at intervals along a second direction E. The first direction Y and the second direction E intersect and are both parallel to the first surface F.

[0060] By making the first doped region 201 include a plurality of first local passivation contacts 21 spaced apart along the second direction E, this is equivalent to setting a plurality of spaced apart first local passivation contacts 21 on the first surface F. Compared with a solution in which the entire layer of the first surface F is provided with the passivation contact material, the setting area of ​​the passivation contact material is reduced, and the absorption of incident light is reduced, thereby reducing the parasitic absorption on one side of the first surface F of the back contact solar cell 100, increasing the short-circuit current of the back contact solar cell 100, and thus improving the efficiency of the back contact solar cell 100.

[0061] In addition, the first doped region 201 includes a plurality of first local passivation contacts 21, and the area of ​​the first doped region 201 can be changed by adjusting the size of a single first local passivation contact 21, so as to flexibly adjust the area ratio of the first doped region 201 on the first surface F. In other words, the overall area ratio of the first doped region 201 can be configured to be the optimal area ratio so as to optimize the efficiency of the solar cell.

[0062] The types of doping elements in the first doping region 201 and the second doping region 202 are opposite. For example, the doping type of the first doping region 201 may be P-type, and the doping type of the second doping region 202 may be N-type. Alternatively, the doping type of the first doping region 201 may be N-type, and the doping type of the second doping region 202 may be P-type.

[0063] The first local passivation contact portions 21 are arranged at intervals along the second direction E. For example, the first local passivation contact portions 21 may be arranged in a row along the second direction E and are spaced apart from each other.

[0064] In the present application, refer to Figure 1, the first electrode 30 includes a plurality of first fine grids 31 arranged at intervals along the first direction Y, each first fine grid 31 extending along the second direction E, and a plurality of first local passivation contacts 21 of one first doping region 201 being in ohmic contact with the corresponding same first fine grid 31. Thus, all the first local passivation contacts 21 in ohmic contact with the same first fine grid 31 form the first doping region 201.

[0065] It can be understood that the back-contact solar cell 100 of the present application can be a main-gridless back-contact solar cell or a main-grid back-contact solar cell.

[0066] In the case of a main-grid back-contact solar cell, the back-contact solar cell 100 may further include a plurality of first main grids 32 extending along the first direction Y, and the plurality of first main grids 32 are arranged at intervals along the second direction E.

[0067] In the embodiment of the present application, the back-contact solar cell 100 further includes a second electrode 50, the second electrode 50 is disposed on the side of the second doping region 202 away from the substrate 10, and the second electrode 50 includes a plurality of second fine grids 51 arranged at intervals along the first direction Y, each second fine grid 51 extending along the second direction E.

[0068] The second doping region 202 includes a plurality of second local passivation contacts 22 arranged at intervals along the second direction E, and the plurality of second local passivation contacts 22 of one second doping region 202 are in ohmic contact with the corresponding same second fine grid 51. Thus, all the second local passivation contacts 22 in ohmic contact with the same second fine grid 51 form the second doping region 202.

[0069] Certainly, in the case of a main-grid back-contact solar cell, the back-contact solar cell 100 may further include a plurality of second main grids 52 extending along the first direction Y, and the plurality of second main grids 32 are arranged at intervals along the second direction E. The first main grids 32 and the second main grids 52 are alternately arranged in the second direction E.

[0070] The first main grid 32 is connected to each first fine grid 31 and is insulated and isolated from each second fine grid 51, and the second main grid 52 is connected to each second fine grid 51 and is insulated and isolated from each first fine grid 31. The first main grid 32 and the second main grid 52 are respectively disposed on the side of the first fine grid 31 and the second fine grid 51 away from the substrate 10.

[0071] In the embodiment of the present application, with reference to Figure 1, both the first fine grid 31 and the second fine grid 51 are configured as continuous strip-shaped structures extending along the second direction E. Each of the first local passivation contact portions 21 and the second local passivation contact portions 22 are evenly distributed along the second direction E. In this way, the intervals between the first local passivation contact portions 21 in the same first doping region 201 along the second direction E are equal, and the intervals between the second local passivation contact portions 22 in the same second doping region 202 along the second direction E are equal.

[0072] At this time, at the intersection position of the first main grid 32 and the second fine grid 51, an insulating portion 60 is interposed between the first main grid 32 and the second fine grid 51. At the intersection position of the second main grid 52 and the first fine grid 31, an insulating portion 60 is interposed between the second main grid 52 and the first fine grid 31.

[0073] Figure 3 It is a schematic diagram of another structure of the back-contact solar cell provided by the embodiment of the present application.

[0074] In the embodiment of the present application, with reference to Figure 3 , in another possible implementation manner, the first fine grid 31 includes a plurality of first sub-grid lines 311 arranged at intervals along the second direction E. The first local passivation contact portions 21 corresponding to the first fine grid 31 are divided into multiple groups and are in ohmic contact with the corresponding plurality of first sub-grid lines 311 group by group. In this way, a group of first local passivation contact portions 21 is provided under each first sub-grid line 311, and no first local passivation contact portions 21 are provided at positions where no first sub-grid lines 311 are provided.

[0075] Furthermore, the second fine grid 51 includes a plurality of second sub-grid lines 511 arranged at intervals along the second direction E. The second local passivation contact portions 22 corresponding to the second fine grid 51 are divided into multiple groups and are in ohmic contact with the corresponding plurality of second sub-grid lines 511 group by group. In this way, a group of second local passivation contact portions 22 is provided under each second sub-grid line 511, and no second local passivation contact portions 22 are provided at positions where no second sub-grid lines 511 are provided.

[0076] The first sub-grid lines 311 included in each first fine grid 31 are arranged in one-to-one alignment in the first direction Y, and the second sub-grid lines 511 included in each second fine grid 51 are also arranged in one-to-one alignment in the first direction Y.

[0077] Figure 4 It is a partial side cross-sectional view of the back-contact solar cell provided by the embodiment of the present application.

[0078] In the embodiment of the present application, in combination with Figure 1 , Figure 2 and Figure 4 , Figure 9, the back-contact solar cell 100 further includes a passivation layer 40, the passivation layer 40 is stacked on the side of the passivation contact layer 20 away from the substrate 10, and the first electrode 30 and the second electrode 50 are disposed on the passivation layer 40. First through holes 41 and second through holes 42 are respectively provided at positions corresponding to each first local passivation contact portion 21 and each second local passivation contact portion 22 on the passivation layer 40. Each first local passivation contact portion 21 is in ohmic contact with the corresponding first fine grid 31 through the first through hole 41, and each second local passivation contact portion 22 is in ohmic contact with the corresponding second fine grid 51 through the second through hole 42.

[0079] In the embodiment of the present application, the outer contour shape of at least one of the first local passivation contact portion 21 and the second local passivation contact portion 22 is configured as a circle or a rhombus or a square.

[0080] Figure 5 It is a schematic diagram of another structure of the back-contact solar cell provided by the embodiment of the present application; Figure 6 It is a schematic diagram of another structure of the back-contact solar cell provided by the embodiment of the present application.

[0081] In the embodiment of the present application, continue to refer to Figure 5 and Figure 6 , the second doping region 202 includes a plurality of second local passivation contact portions 22 arranged at intervals along the first direction Y, the second local passivation contact portions 22 are arranged in one-to-one correspondence with the first fine grids 31, and the projection of the second local passivation contact portion 22 on the first surface F covers the projection of the corresponding second fine grid 51 on the first surface F.

[0082] When specifically implemented, Figure 5 is an improvement based on Figure 3 , each second local passivation contact portion 22 includes a plurality of short strip shapes extending along the second direction E, and each short strip structure corresponds to a first sub-grid line 311. Except for the improvement of the second local passivation contact portion 22, the remaining structures are similar to Figure 3 , and will not be described in detail here.

[0083] Figure 6 is an improvement based on Figure 1 , each second local passivation contact portion 22 is configured as a continuous long strip shape extending along the second direction, and each long strip structure corresponds to a first fine grid 31. Except for the improvement of the second local passivation contact portion 22, the remaining structures are similar to Figure 1 , and will not be described in detail here.

[0084] In the embodiment of the present application, the distance between adjacent first local passivation contact portions 21 is not greater than 1000 microns, the distance between adjacent second local passivation contact portions 22 is not greater than 1000 microns, and the distance between adjacent first local passivation contact portions 21 and second local passivation contact portions 22 is not greater than 1000 microns.

[0085] In addition, at least one of the first local passivation contact portion 21 and the second local passivation contact portion 22 includes a metal compound layer, or a semiconductor layer, or a semiconductor compound layer.

[0086] Or at least one of the first local passivation contact portion 21 and the second local passivation contact portion 22 includes a stack of an oxide layer and a polysilicon doped conductive layer.

[0087] Or at least one of the first local passivation contact portion 21 and the second local passivation contact portion 22 includes a stack of an intrinsic amorphous silicon layer and a doped polysilicon layer.

[0088] In a second aspect of the embodiments of the present application, a photovoltaic module is further provided, including at least one battery string, and the battery string includes at least two of the back-contact solar cells 100 described in the foregoing embodiments. The back-contact solar cells 100 can be connected together by string soldering.

[0089] In a third aspect of the embodiments of the present application, a photovoltaic system is further provided, including the above photovoltaic module.

[0090] Figure 7 Schematic diagrams for forming the first local passivation contact structure and the second local passivation contact structure in the manufacturing method of the back-contact solar cell provided by the embodiments of the present application; Figure 8 Schematic diagrams for forming a passivation layer in the manufacturing method of the back-contact solar cell provided by the embodiments of the present application; Figure 9 Schematic diagrams for forming the first through hole and the second through hole in the manufacturing method of the back-contact solar cell provided by the embodiments of the present application; Figure 10 Schematic diagrams for forming the first electrode and the second electrode in the manufacturing method of the back-contact solar cell provided by the embodiments of the present application; Figure 11 Schematic diagrams for forming the first local passivation contact structure and the second local passivation contact structure in the manufacturing method of the back-contact solar cell provided by the embodiments of the present application; Figure 12 Schematic diagrams for forming a passivation layer in the manufacturing method of the back-contact solar cell provided by the embodiments of the present application; Figure 13 Schematic diagrams for forming the first through hole in the manufacturing method of the back-contact solar cell provided by the embodiments of the present application; Figure 14 Schematic diagrams for forming a contact groove on the passivation layer in the manufacturing method of the back-contact solar cell provided by the embodiments of the present application; Figure 15 Schematic diagrams for forming the first electrode and the second electrode in the manufacturing method of the back-contact solar cell provided by the embodiments of the present application; Figure 16 Schematic diagrams for forming another structure of a contact groove on the passivation layer in the manufacturing method of the back-contact solar cell provided by the embodiments of the present application; Figure 17Schematic diagram of forming a first electrode and a second electrode in the manufacturing method of the back-contact solar cell provided by the embodiment of the present application.

[0091] The fourth aspect of the embodiment of the present application further provides a manufacturing method of a back-contact solar cell.

[0092] The method includes:

[0093] Step 1, referring to Figure 7 , form a plurality of first local passivation contact parts 21 and a plurality of second local passivation contact parts 22 on the first surface F of the substrate 10. The doping types of the first local passivation contact parts 21 and the second local passivation contact parts 22 are opposite. The plurality of first local passivation contact parts 21 and the plurality of second local passivation contact parts 22 are both arranged in a row along the second direction E.

[0094] Step 2, referring to Figure 8 , deposit a passivation layer 40 in one whole layer on one side of the first surface F of the substrate 10. The passivation layer 40 is an insulating layer, which can be but is not limited to silicon nitride, silicon oxynitride, silicon oxide, aluminum oxide, or a stacked structure of the above materials.

[0095] Step 3, referring to Figure 9 , open a first through hole 41 at the position of the passivation layer 40 corresponding to the first local passivation contact part 21, and open a second through hole 42 at the position of the passivation layer 40 corresponding to the second local passivation contact part 22. The size of the first through hole 41 can be less than or equal to the first local passivation contact part 21. The size of the second through hole 42 can be less than or equal to the second local passivation contact part 22.

[0096] Step 4, referring to 10, form a first electrode 30 and a second electrode 50 on the passivation layer 40. The first electrode 30 is in ohmic contact with the first local passivation contact part 21, and the second electrode 50 is in ohmic contact with the second local passivation contact part 22.

[0097] In some other embodiments, the manufacturing method of the back-contact solar cell may include:

[0098] Step 1, referring to Figure 11 , form a plurality of first local passivation contact parts 21 and a plurality of second local passivation contact parts 22 on the first surface F of the substrate 10. The doping types of the first local passivation contact parts 21 and the second local passivation contact parts 22 are opposite. The plurality of first local passivation contact parts 21 are arranged in a row along the second direction E. The second local passivation contact part 22 is in a strip shape extending along the second direction E.

[0099] Step 2, referring to Figure 12, a passivation layer 40 is deposited as a whole layer on one side of the first surface F of the substrate 10. The passivation layer 40 is an insulating layer, which can be but is not limited to silicon nitride, silicon oxynitride, silicon oxide, aluminum oxide, or a stacked structure of the above materials.

[0100] Step 3, referring to Figure 13 , at the position of the passivation layer 40 corresponding to the first local passivation contact portion 21, a first through hole 41 is opened, and at the position of the passivation layer 40 corresponding to the second local passivation contact portion 22, a second through hole 42 is opened. The size of the first through hole 41 can be less than or equal to the first local passivation contact portion 21.

[0101] Step 4, referring to Figure 14 , at the position of the passivation layer 40 corresponding to the second local passivation contact portion 22, a contact groove 43 extending along the second direction E is opened. Or the contact groove 43 can also be opened in multiple numbers along the second direction E as shown in Figure 16 and are arranged at intervals from each other.

[0102] Step 5, referring to Figure 15 , Figure 17 , a first electrode 30 and a second electrode 50 are formed on the passivation layer 40. The first electrode 30 is in ohmic contact with the first local passivation contact portion 21, and the second electrode 50 is in ohmic contact with the second local passivation contact portion 22. Figure 15 Corresponding to Figure 14 's structure, Figure 17 Corresponding to Figure 16 's structure.

[0103] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0104] The above-described embodiments only represent several implementation manners of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several modifications and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the utility model patent shall be subject to the appended claims.

Claims

1. A back contact solar cell, characterized in that: include: a substrate comprising a first surface; a passivation contact layer, the passivation contact layer being disposed on the first surface, and comprising first doping regions and second doping regions arranged alternately and at intervals along a first direction, and the types of doping elements of the first doping regions and the second doping regions are opposite; and A first electrode, the first electrode is disposed on a side of the first doped region facing away from the substrate and is in ohmic contact with the first doped region; The first doped region includes a plurality of first local passivation contact portions arranged at intervals along a second direction, and the first direction and the second direction intersect and are both parallel to the first surface.

2. The back contact solar cell according to claim 1, characterized in that: The first electrode includes a plurality of first fine gates arranged at intervals along the first direction, each of the first fine gates extends along the second direction, and the plurality of first local passivation contacts of one of the first doping regions are in ohmic contact with the corresponding first fine gate.

3. The back contact solar cell according to claim 2, characterized in that: The back-contact solar cell further includes a second electrode, which is disposed on a side of the second doping region away from the substrate, and includes a plurality of second fine grids spaced apart along the first direction, each of the second fine grids extending along the second direction; The second doping region includes a plurality of second local passivation contacts arranged at intervals along a second direction, and the plurality of second local passivation contacts of one second doping region are in ohmic contact with the corresponding second fine gate.

4. The back contact solar cell according to claim 3, characterized in that: The first fine grid and the second fine grid are both configured as continuous strip structures extending along the second direction; The first local passivation contact portions and the second local passivation contact portions are evenly distributed along the second direction.

5. The back contact solar cell according to claim 3, characterized in that: The first fine gate includes a plurality of first sub-gate lines arranged at intervals along the second direction, the first local passivation contact portions corresponding to the first fine gate are a plurality of groups, and are in ohmic contact with the corresponding plurality of first sub-gate lines group by group; and / or The second fine gate includes a plurality of second sub-gate lines arranged at intervals along a second direction. The second local passivation contact portions corresponding to the second fine gate are in a plurality of groups and are in ohmic contact with the corresponding second sub-gate lines group by group.

6. The back contact solar cell according to claim 3, characterized in that: The back contact solar cell further comprises a passivation layer, the passivation layer is stacked and arranged on a side of the passivation contact layer away from the substrate, and the first electrode and the second electrode are arranged on the passivation layer; The passivation layer is provided with a first through hole and a second through hole at positions corresponding to each of the first local passivation contact portions and each of the second local passivation contact portions, respectively; Each of the first local passivation contact portions is in ohmic contact with the corresponding first fine grid through the first through hole; each of the second local passivation contact portions is in ohmic contact with the corresponding second fine grid through the second through hole.

7. The back contact solar cell according to claim 3, characterized in that: An outer contour shape of at least one of the first local passivation contact portion and the second local passivation contact portion is configured as a circle, a rhombus, or a square.

8. The back contact solar cell according to claim 3, characterized in that: The spacing between adjacent first local passivation contacts is not greater than 1000 micrometers, the spacing between adjacent second local passivation contacts is not greater than 1000 micrometers, and the spacing between adjacent first local passivation contacts and second local passivation contacts is not greater than 1000 micrometers.

9. The back contact solar cell according to claim 2, characterized in that: The back-contact solar cell further includes a second electrode, which is disposed on a side of the second doping region away from the substrate, and includes a plurality of second fine grids spaced apart along the first direction, each of the second fine grids extending along the second direction; The second doped region includes a plurality of second local passivation contacts arranged at intervals along a first direction, the second local passivation contacts are arranged one-to-one with the first fine gates, and a projection of the second local passivation contact on the first surface covers a projection of the corresponding second fine gate on the first surface.

10. A photovoltaic module, characterized in that: The invention comprises at least one cell string, wherein the cell string comprises at least two back-contact solar cells according to any one of claims 1 to 9.

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