Back contact photovoltaic cell and photovoltaic module

Abstract

This application relates to a back-contact photovoltaic cell and a photovoltaic module, and pertains to the field of photovoltaic technology. The back-contact photovoltaic cell includes a silicon substrate, which comprises a base region, at least two P-type doped regions, and at least two N-type doped regions. The P-type and N-type doped regions are spaced apart along a first direction. The base region includes a first separating region disposed between the P-type and N-type doped regions. At least two P-type doped regions and at least two N-type doped regions are spaced apart along a second direction, and the first and second directions intersect. In this application, the first separating region absorbs energy from different wavelengths of light, and the parasitic absorption of the P-type and N-type doped regions is relatively small. Therefore, the photoelectric conversion efficiency of the back-contact photovoltaic cell is relatively high, and the output power of the photovoltaic module is relatively high.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and in particular to a back-contact photovoltaic cell and photovoltaic module. Background Technology

[0002] In related technologies, back-contact photovoltaic cells include a silicon substrate and grid electrodes. The grid electrodes are disposed on the back-light-receiving side of the silicon substrate, ensuring that the light-receiving side of the silicon substrate is not blocked by the grid electrodes. However, the photoelectric conversion efficiency of back-contact photovoltaic cells still needs improvement in these technologies. Summary of the Invention

[0003] This application provides a back-contact photovoltaic cell and a photovoltaic module to improve the photoelectric conversion efficiency of the back-contact photovoltaic cell and the output power of the photovoltaic module.

[0004] This application provides a back-contact photovoltaic cell. The back-contact photovoltaic cell includes a silicon substrate. The silicon substrate includes a base region, at least two P-type doped regions, and at least two N-type doped regions. The P-type doped regions and N-type doped regions are spaced apart along a first direction. The base region includes a first separating region disposed between the P-type doped regions and the N-type doped regions. The at least two P-type doped regions are spaced apart along a second direction, and the at least two N-type doped regions are spaced apart along the second direction. The first direction and the second direction intersect.

[0005] This application provides a photovoltaic module, which includes a battery string, the battery string including at least two electrically connected photovoltaic cells, and the photovoltaic cells are back-contact photovoltaic cells provided in this application.

[0006] In the back-contact photovoltaic cell of this application, the silicon substrate includes a first surface and a second surface disposed opposite to each other. The first surface is directly and primarily irradiated by sunlight. P-type doped regions, N-type doped regions, and a first separating region are all disposed on the second surface. The first separating region intrinsically absorbs long-wavelength sunlight. Ambient light exists in the operating environment of the back-contact photovoltaic cell. When ambient light directly or primarily irradiates the second surface, the first separating region also intrinsically absorbs short-wavelength ambient light. Under the above arrangement, the first separating region intrinsically absorbs energy from different wavelengths of light, thereby generating a relatively large number of electron-hole pairs within the silicon substrate. Because at least two P-type doped regions are spaced apart along a second direction on the second surface, and because at least two N-type doped regions are spaced apart along a second direction on the second surface, the degree of parasitic absorption of long-wavelength sunlight by the P-type and N-type doped regions is relatively small. Therefore, the photoelectric conversion efficiency of the back-contact photovoltaic cell is relatively high, and correspondingly, the output power of the photovoltaic module is relatively high.

[0007] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this application. Attached Figure Description

[0008] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the back-contact photovoltaic cell in the first embodiment. Figure 2 for Figure 1 A schematic cross-sectional view of the back-contact photovoltaic cell along direction AA. Figure 3 for Figure 1 A schematic cross-sectional view of the back-contact photovoltaic cell along direction BB. Figure 4 This is a schematic diagram of the structure of a silicon substrate in the first embodiment; Figure 5 This is a schematic diagram of the back-contact photovoltaic cell in the second embodiment; Figure 6 This is a schematic diagram of the back-contact photovoltaic cell in the third embodiment. Figure 7 A schematic diagram of the silicon substrate in the third embodiment; Figure 8 This is a schematic diagram of the back-contact photovoltaic cell in the fourth embodiment. Figure 9 This is a schematic diagram of the silicon substrate in the fourth embodiment; Figure 10 This is a schematic diagram of the silicon substrate in the fifth embodiment; Figure 11 This is a schematic diagram of the back-contact photovoltaic cell in the sixth embodiment; Figure 12 This is a schematic diagram of the silicon substrate in the sixth embodiment; Figure 13 This is a schematic diagram of the back-contact photovoltaic cell in the seventh embodiment; Figure 14 This is a schematic diagram of the silicon substrate in the seventh embodiment; Figure 15 This is a schematic diagram of the silicon substrate in the eighth embodiment; Figure 16This is a schematic diagram of the back-contact photovoltaic cell in the ninth embodiment; Figure 17 This is a schematic diagram of the back-contact photovoltaic cell in the ninth embodiment; Figure 18 A partial structural schematic diagram of the base region, P-type doped region, third intrinsic amorphous silicon, first metal reflective layer and first passivation structure in the tenth embodiment; Figure 19 A partial structural schematic diagram of the base region, N-type doped region, fourth intrinsic amorphous silicon, second metal reflective layer and first passivation structure in the eleventh embodiment; Figure 20 This is a partial structural schematic diagram of a silicon substrate, a first gate electrode, and a first passivation structure in some embodiments; Figure 21 This is a partial structural diagram of a silicon substrate, a second gate electrode, and a first passivation structure in some embodiments.

[0010] Figure reference numerals: 10-Back contact photovoltaic cell, 1-Silicon substrate, 1a-First side, 1b-Second side, 11-Base region, 111-First separating region, 112-Second separating region, 113-Third separating region, 12-P-type doped region, 13-N-type doped region, 21-First intrinsic polycrystalline silicon, 22-Second intrinsic polycrystalline silicon, 31-First intrinsic microcrystalline silicon, 32-Second intrinsic microcrystalline silicon, 41-First intrinsic amorphous silicon, 42-Second intrinsic amorphous silicon Intrinsic amorphous silicon, 43-Third intrinsic amorphous silicon, 44-Fourth intrinsic amorphous silicon, 51-First passivation structure, 52-Second passivation structure, 61-First gate electrode, 611-First reflective portion, 612-First conductive body, 613-First electrical connection portion, 62-Second gate electrode, 621-Second reflective portion, 622-Second conductive body, 623-Second electrical connection portion, 71-First metal reflective layer, 72-Second metal reflective layer. Detailed Implementation

[0011] To better understand the technical solutions of this application, the embodiments of this application are described in detail below with reference to the accompanying drawings. It should be understood that the described embodiments are merely some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this application. The terminology used in the embodiments of this application is for the purpose of describing specific embodiments only, and is not intended to limit this application. The singular forms "a," "described," and "the" used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should be understood that the term "and / or" used herein is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship. Furthermore, the ordinal numbers "first," "second," "third," "fourth," "fifth," and "sixth" in this document are used to avoid confusion of constituent elements, and are not necessarily intended to limit the quantity. In the accompanying drawings, each pair of the first direction X, the second direction Y, and the third direction Z can be perpendicular to each other. The fourth direction L can be the reverse of the first direction X, the fifth direction M can be the reverse of the second direction Y, and the sixth direction N can be the reverse of the third direction Z. For clarity, the proportions of layers, films, regions, etc., in the accompanying drawings may not represent the proportions of actual structures. It should be understood that when feature a (e.g., passivation structure, part, layer, film, region, gate electrode) is mentioned as being "disposed on" or "located" on feature b (e.g., passivation structure, part, layer, film, region, substrate, wall, surface), feature a can be directly disposed on or directly located on feature b, or there may be other features c between feature a and feature b. Conversely, when feature a is mentioned as being "directly located" or "directly disposed" on feature b, it indicates that there are no other features between feature a and feature b. It should be understood that the meaning of electrical connection can include: after two structures with conductive properties are physically connected, under the action of an electric field, one of the two physically connected structures with conductive properties can conduct electricity to the other. The physical connection used for conduction can be a direct connection or an indirect connection through other conductive media.

[0012] This application provides some embodiments of back-contact photovoltaic cells; please refer to them. Figure 1As shown, the back-contact photovoltaic cell 10 includes a silicon substrate 1, which includes a first surface 1a and a second surface 1b. The first surface 1a is the surface directly or primarily exposed to sunlight. The first surface 1a and the second surface 1b are arranged opposite to each other along the thickness direction of the silicon substrate 1. The silicon substrate 1 includes a base region 11, a P-type doped region 12, and an N-type doped region 13. For the back-contact photovoltaic cell 10, both the P-type doped region 12 and the N-type doped region 13 are disposed on the second surface 1b. The P-type doped region 12 and the N-type doped region 13 are spaced apart along a first direction X. The base region 11 includes a first separating region 111, which is disposed between the P-type doped region 12 and the N-type doped region 13. For sunlight, the P-type doped region 12 and the N-type doped region 13 exhibit parasitic absorption on the second surface 1b, while the first separating region 111 exhibits intrinsic absorption on the second surface 1b. When sunlight directly or primarily illuminates the first surface 1a, the sunlight passes sequentially through the first surface 1a and the second surface 1b. For the sunlight passing sequentially through the first surface 1a and the second surface 1b, the region near the second surface 1b within the silicon substrate 1 absorbs the long-wavelength light of the sunlight. Correspondingly, the first separating region 111 intrinsically absorbs the long-wavelength light of the sunlight. In practical applications, ambient light also exists in the environment where the back-contact photovoltaic cell 10 is located. Ambient light can include sunlight reflected by objects in the environment, such as the ground, supports, and buildings. When ambient light directly or primarily illuminates the second surface 1b, the ambient light passes sequentially through the second surface 1b and the first surface 1a. For the ambient light passing sequentially through the second surface 1b and the first surface 1a, the region near the second surface 1b within the silicon substrate 1 absorbs the short-wavelength light of the ambient light. Correspondingly, the first separating region 111 intrinsically absorbs the short-wavelength light of the ambient light. Under the above configuration, the first separation region 111 intrinsically absorbs the energy of light of different wavelengths, so as to generate a relatively large number of electron-hole pairs in the silicon substrate 1, thereby making the photoelectric conversion efficiency of the back contact photovoltaic cell 10 relatively large.

[0013] From another perspective, by utilizing the space between the P-type doped region 12 and the N-type doped region 13, a local region of the base region 11 is extended between the P-type doped region 12 and the N-type doped region 13, so that the area of ​​the base region 11 used for intrinsic absorption is relatively large, thereby making the number of electron-hole pairs that the silicon substrate 1 can generate relatively large.

[0014] In some embodiments, please refer to Figure 2 As shown, the silicon substrate 1 includes at least two P-type doped regions 12 spaced apart along the second direction Y. In this configuration, the ratio of the area of ​​the P-type doped region 12 on the second surface 1b to the area of ​​the second surface 1b is relatively small, and the degree of parasitic absorption of long-wavelength sunlight by the P-type doped region 12 is relatively small. Therefore, the photoelectric conversion efficiency of the back-contact photovoltaic cell 10 is relatively large.

[0015] In some embodiments, please refer to Figure 3 As shown, the silicon substrate 1 includes at least two N-type doped regions 13 spaced apart along the second direction Y. In this configuration, the ratio of the area of ​​the N-type doped region 13 on the second surface 1b to the area of ​​the second surface 1b is relatively small, and the degree of parasitic absorption of long-wavelength sunlight by the N-type doped region 13 is relatively small. Therefore, the photoelectric conversion efficiency of the back-contact photovoltaic cell 10 is relatively large.

[0016] In some embodiments, the silicon substrate 1 may include monocrystalline silicon or polycrystalline silicon.

[0017] In some embodiments, the base region 11 serves as the main region within the silicon substrate 1. The base region 11 may be doped with N-type elements, which refer to elements in the fifth group of the periodic table, such as phosphorus, arsenic, antimony, etc.

[0018] In some embodiments, the P-type doped region 12 may include: a region within the silicon substrate 1 doped with at least one P-type element. A P-type element refers to a Group 3 element in the periodic table, such as boron, aluminum, gallium, etc.

[0019] In some embodiments, the activation doping concentration of the p-type doped region 12 with respect to p-type elements can be greater than or equal to 1E17 atoms / cm². 3 "1E17" is the scientific notation for "ten to the power of seventeen". Additionally, atoms / cm 3 This indicates the number of atoms per cubic centimeter. Furthermore, the method for measuring the concentration of activated doping can be electrochemical capacitance-voltage profiling (ECV), or ECV analysis for short. The equipment for measuring the concentration of activated doping can be an electrochemical analyzer, or ECV tester for short.

[0020] In some embodiments, the P-type doped region 12 can be understood as a region extending a certain depth from the second surface 1b into the silicon substrate 1.

[0021] In some embodiments, the meaning of N-type doped region 13 may include: a region within silicon substrate 1 doped with at least one N-type element.

[0022] In some embodiments, when both the base region 11 and the N-type doped region 13 are doped with N-type elements, the activation doping concentration of the N-type doped region 13 with respect to the N-type elements is greater than the activation doping concentration of the base region 11 with respect to the N-type elements.

[0023] In some embodiments, the activation doping concentration of the N-type doped region 13 with respect to the N-type element is greater than 1E17 atoms / cm³. 3 .

[0024] In some embodiments, the N-type doped region 13 can be understood as a region extending a certain depth from the second surface 1b into the silicon substrate 1.

[0025] In some embodiments, intrinsic absorption may include: the light absorption process that generates electron-hole pairs within the silicon substrate 1.

[0026] In some embodiments, parasitic absorption may include: no light absorption process of electron-hole pairs is generated within the silicon substrate 1.

[0027] In some embodiments, for the silicon substrate 1, long-wavelength sunlight includes light with wavelengths in the range of 700 nanometers (nm) to 1000 nanometers (nm).

[0028] In some embodiments, for the silicon substrate 1, the short-wavelength ambient light includes light with a wavelength in the range of 300 nm to 500 nm.

[0029] In some embodiments, the first direction X and the second direction Y can be perpendicular. Due to limitations in actual manufacturing processes, some errors are allowed, meaning that the first direction X and the second direction Y can be approximately perpendicular.

[0030] In some other embodiments (not shown in the figure), there may be a relatively obvious acute or obtuse angle between the first direction and the second direction.

[0031] In some embodiments, for the silicon substrate 1 being an N-type silicon substrate, or for the base region 11 being doped with N-type elements, the first partition region 111 is not doped with P-type elements, or the first partition region 111 may be doped with a very small amount of P-type elements, for example, boron doping concentration less than 1E15 atoms / cm². 3 .

[0032] Understandably, the approximate range of the first dividing zone 111 can be referenced as follows: Figure 1 The area within the rectangle shown by the dashed line. Figure 1 In the diagram, to clearly indicate the extent of the first separating region 111, the boundary line of the first separating region 111 is spaced apart from the boundary line of the P-type doped region 12, and the boundary line of the first separating region 111 is spaced apart from the boundary line of the N-type doped region 13. In the actual back-contact photovoltaic cell 10, there is no clear boundary between the first separating region 111 and the P-type doped region 12, and there is no clear boundary between the first separating region 111 and the N-type doped region 13.

[0033] In some embodiments, please refer to Figure 2 As shown, the base region 11 may further include a second partition region 112. The second partition region 112 and the P-type doped region 12 are alternately arranged along the second direction Y. This can also be understood as a second partition region 112 being provided between two P-type doped regions 12 spaced apart along the second direction Y. Under this arrangement, more of the long-wavelength sunlight and short-wavelength ambient light are intrinsically absorbed by the first partition region 111 and the second partition region 112, while less of the long-wavelength sunlight is parasiticly absorbed by the P-type doped region 12. Therefore, the photoelectric conversion efficiency of the back-contact photovoltaic cell 10 is relatively high.

[0034] From another perspective, by utilizing the space between the two P-type doped regions 12, a local region of the base region 11 is extended between the two P-type doped regions 12, so that the area of ​​the base region 11 used for intrinsic absorption is relatively large, thereby making the number of electron-hole pairs that the silicon substrate 1 can generate relatively large.

[0035] In some embodiments, the number of P-type doped regions 12 spaced apart along the second direction Y is j, and correspondingly, the number of second partition regions 112 is (j-1), where j is a natural number greater than or equal to 2. When j is greater than or equal to 3, a second partition region 112 is provided between every two P-type doped regions 12 spaced apart along the second direction Y.

[0036] In some embodiments, for the silicon substrate 1 being an N-type silicon substrate, or for the base region 11 being doped with N-type elements, the second partition region 112 is not doped with P-type elements; or, the second partition region 112 may be doped with a very small amount of P-type elements, for example, boron doping concentration less than 1E15 atoms / cm². 3 .

[0037] Understandably, the approximate extent of the second dividing zone 112 can be referenced as follows: Figure 2 The area within the rectangle shown by the dashed line. Figure 2 In order to clearly indicate the range of the second separation region 112, the boundary line of the second separation region 112 is spaced apart from the boundary line of the P-type doped region 12. In the actual back contact photovoltaic cell 10, there is no clear boundary between the second separation region 112 and the P-type doped region 12.

[0038] In some embodiments, please refer to Figure 3As shown, the base region 11 may also include a third partition region 113. The third partition region 113 and the N-type doped region 13 are alternately arranged along the second direction Y. This can also be understood as the third partition region 113 being disposed between two N-type doped regions 13 spaced apart along the second direction Y. Under this arrangement, long-wavelength sunlight and short-wavelength ambient light are more intrinsically absorbed by the first partition region 111 and the third partition region 113, while long-wavelength sunlight is less parasiticly absorbed by the N-type doped region 13. Therefore, the photoelectric conversion efficiency of the back-contact photovoltaic cell 10 is relatively high.

[0039] From another perspective, by utilizing the space between the two N-type doped regions 13, a local region of the base region 11 is extended between the two N-type doped regions 13, so that the area of ​​the base region 11 used for intrinsic absorption is relatively large, thereby making the number of electron-hole pairs that the silicon substrate 1 can generate relatively large.

[0040] In some embodiments, the number of N-type doped regions 13 spaced apart along the second direction Y is k, and correspondingly, the number of third partition regions 113 is (k-1), where k is a natural number greater than or equal to 2. When k is greater than or equal to 3, a third partition region 113 is provided between every two N-type doped regions 13 spaced apart along the second direction Y.

[0041] In some embodiments, for the silicon substrate 1 being an N-type silicon substrate, or for the base region 11 being doped with an N-type element, the active doping concentration of the N-type doped region 13 with respect to the N-type element is greater than the active doping concentration of the N-type element in the third partition region 113.

[0042] Understandably, the approximate extent of the third dividing zone 113 can be referenced as follows: Figure 3 The area within the rectangle shown by the dashed line. Figure 3 In order to clearly indicate the range of the third partition region 113, the boundary line of the third partition region 113 is spaced apart from the boundary line of the N-type doped region 13. In the actual back contact photovoltaic cell 10, there is no clear boundary between the third partition region 113 and the N-type doped region 13.

[0043] In some embodiments, please refer to Figure 4 As shown, the base region 11 may include the first partition region 111, the second partition region 112 and the third partition region 113 mentioned above. The P-type doped region 12 and the N-type doped region 13 are arranged alternately along the first direction X. The first partition region 111 is disposed between the P-type doped region 12 and the N-type doped region 13. The second partition region 112 and the P-type doped region 12 are arranged alternately along the second direction Y. The third partition region 113 and the N-type doped region 13 are arranged alternately along the second direction Y.

[0044] In some embodiments, please refer to Figure 4As shown, the first partition 111 is connected to the second partition 112, and the first partition 111 is connected to the third partition 113. The first partition 111 is located between the second partition 112 and the third partition 113.

[0045] In some embodiments, please refer to Figure 1 and Figure 4 As shown, the base region 11 may include a first partition region 111. At least two P-type doped regions 12 spaced apart along the second direction Y may be provided on one side of the first partition region 111, and at least two N-type doped regions 13 spaced apart along the second direction Y may be provided on the other side of the first partition region 111.

[0046] In some embodiments, please refer to Figure 4 As shown, the P-type doped region 12 may have a first length D1 along the second direction Y, and the first length D1 may be in the range of 100 micrometers (μm) to 10,000 micrometers (μm). Specifically, the first length D1 may be 100 μm, 500 μm, 1000 μm, 2000 μm, 3000 μm, 4000 μm, 5000 μm, 6000 μm, 7000 μm, 8000 μm, 9000 μm or 10000 μm.

[0047] In some other embodiments, please refer to Figure 4 As shown, the first length D1 can also be in the range of 100μm to 1000μm. Specifically, the first length D1 can be 100μm, 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm or 1000μm.

[0048] In some other embodiments, please refer to Figure 4 As shown, the first length D1 can also be in the range of 100μm to 500μm. Specifically, the first length D1 can be 100μm, 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm or 500μm.

[0049] In some embodiments, please refer to Figure 4 As shown, a single P-type doped region 12 can have a first width D2 along the first direction X, and the first width D2 can be in the range of 50 μm to 200 μm. Specifically, the first width D2 can be 50 μm, 100 μm, 150 μm or 200 μm.

[0050] In some other embodiments, please refer to Figure 4As shown, the first width D2 can also be within the range of 50μm to 100μm. Specifically, the first width D2 can be 50μm, 60μm, 70μm, 80μm, 90μm, or 100μm.

[0051] In some other embodiments, please refer to Figure 4 As shown, the first width D2 can also be within the range of 100μm to 200μm. Specifically, the first width D2 can be 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, or 200μm.

[0052] In some embodiments, please refer to Figure 4 As shown, a first spacing distance D3 exists between the two P-type doped regions 12 along the second direction Y. The first spacing distance D3 can be in the range of 50 μm to 500 μm. Specifically, the first spacing distance D3 can be 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, or 500 μm.

[0053] In some other embodiments, please refer to Figure 4 As shown, the first interval distance D3 can also be within the range of 50μm to 200μm. Specifically, the first interval distance D3 can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, or 200μm.

[0054] In some other embodiments, please refer to Figure 4 As shown, the first interval distance D3 can also be within 200μm to 500μm. Specifically, the first interval distance D3 can be 200μm, 250μm, 300μm, 350μm, 400μm, 450μm or 500μm.

[0055] In some embodiments, please refer to Figure 4 As shown, the N-type doped region 13 may have a second length D4 along the second direction Y. The range and value of the second length D4 can be referred to the range and value of the first length D1 described above, and will not be repeated here.

[0056] In some embodiments, please refer to Figure 4 As shown, the N-type doped region 13 may have a second width D5 along the first direction X. The range and value of the second width D5 can be referred to the range and value of the first width D2 described above, and will not be repeated here.

[0057] In some embodiments, please refer to Figure 4 As shown, there is a second spacing distance D6 between the two N-type doped regions 13 along the second direction Y. The range and value of the second spacing distance D6 can be referred to the range and value of the first spacing distance D3 described above, and will not be repeated here.

[0058] In some embodiments, please refer to Figure 4 As shown, the first separating region 111 has a third width D7 along the first direction X, and the third width D7 can be in the range of 50 μm to 300 μm. Specifically, the third width D7 can be 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, or 300 μm. Alternatively, the third width D7 can also be understood as the spacing distance along the first direction X between the P-type doped region 12 and the N-type doped region 13.

[0059] In some other embodiments, please refer to Figure 4 As shown, the third width D7 can also be in the range of 50μm to 100μm. Specifically, the third width D7 can be 50μm, 60μm, 70μm, 80μm, 90μm, or 100μm.

[0060] In some other embodiments, please refer to Figure 4 As shown, the third width D7 can also be in the range of 50μm to 70μm. Specifically, the third width D7 can be 50μm, 51μm, 52μm, 53μm, 54μm, 55μm, 56μm, 57μm, 58μm, 59μm, 60μm, 61μm, 62μm, 63μm, 64μm, 65μm, 66μm, 67μm, 68μm, 69μm, or 70μm.

[0061] In some embodiments, please refer to Figure 5 As shown, the base region 11 may include three or more odd-numbered first partition regions 111 spaced apart along the first direction X. At least two P-type doped regions 12 spaced apart along the second direction Y may be provided on one side of any first partition region 111, and at least two N-type doped regions 13 spaced apart along the second direction Y may be provided on the other side of any first partition region 111.

[0062] In some embodiments, please refer to Figure 6 and Figure 7 As shown, the back-contact photovoltaic cell 10 may include a first intrinsic polycrystalline silicon 21, and the first intrinsic polycrystalline silicon 21 and the P-type doped region 12 are alternately arranged along the second direction Y. This can also be understood as... Figure 1 , Figure 2 and Figure 4 Based on the embodiment shown, the second partition 112 is replaced with as shown Figure 6 and Figure 7 The first intrinsic polycrystalline silicon 21 is shown. In this configuration, long-wavelength sunlight and short-wavelength ambient light are more intrinsically absorbed by the first separating region 111 and the first intrinsic polycrystalline silicon 21, while long-wavelength sunlight is less parasiticly absorbed by the P-type doped region 12. Therefore, the photoelectric conversion efficiency of the back-contact photovoltaic cell 10 is relatively high.

[0063] Understandably, although the intrinsic absorption of the first intrinsic polysilicon 21 is weaker than that of the second partition region 112, the parasitic absorption of the first intrinsic polysilicon 21 is still weaker than that of the P-type doped region 12.

[0064] In some embodiments, please refer to Figure 7 As shown, the first intrinsic polysilicon 21 and the P-type doped region 12 are alternately arranged along the second direction Y, and the third partition region 113 and the N-type doped region 13 are alternately arranged along the second direction Y.

[0065] In some embodiments, please refer to Figure 8 and Figure 9 As shown, the back-contact photovoltaic cell 10 may include a second intrinsic polycrystalline silicon 22, and the second intrinsic polycrystalline silicon 22 and the N-type doped region 13 are alternately arranged along the second direction Y. This can also be understood as... Figure 1 , Figure 3 and Figure 4 Based on the embodiment shown, the third partition 113 is replaced with, as shown in the example. Figure 8 and Figure 9 The second intrinsic polycrystalline silicon 22 is shown. In this configuration, long-wavelength sunlight and short-wavelength ambient light are more intrinsically absorbed by the first separating region 111 and the second intrinsic polycrystalline silicon 22, while long-wavelength sunlight is less parasiticly absorbed by the N-type doped region 13. Therefore, the photoelectric conversion efficiency of the back-contact photovoltaic cell 10 is relatively high.

[0066] Understandably, although the intrinsic absorption of the second intrinsic polysilicon 22 is weaker than that of the third partition region 113, the parasitic absorption of the second intrinsic polysilicon 22 is still weaker than that of the N-type doped region 13.

[0067] In some embodiments, please refer to Figure 9 As shown, the second partition region 112 and the P-type doped region 12 are alternately arranged along the second direction Y, and the second intrinsic polysilicon 22 and the N-type doped region 13 are alternately arranged along the second direction Y.

[0068] In some embodiments, please refer to Figure 10As shown, the back-contact photovoltaic cell 10 can simultaneously include a first intrinsic polycrystalline silicon 21 and a second intrinsic polycrystalline silicon 22. The first intrinsic polycrystalline silicon 21 and the P-type doped region 12 are alternately arranged along the second direction Y, and the second intrinsic polycrystalline silicon 22 and the N-type doped region 13 are alternately arranged along the second direction Y. A first separating region 111 is disposed between the P-type doped region 12 and the N-type doped region 13. The relevant technical effects have been described above and will not be repeated here.

[0069] It is understandable that the meaning of intrinsic polycrystalline silicon can include: silicon materials with a polycrystalline structure that have not undergone artificial doping treatment.

[0070] In some embodiments, please refer to Figure 11 and Figure 12 As shown, the back-contact photovoltaic cell 10 may include a first intrinsic microcrystalline silicon 31, and the first intrinsic microcrystalline silicon 31 and the P-type doped region 12 are alternately arranged along the second direction Y. This can also be understood as... Figure 1 , Figure 2 and Figure 4 Based on the embodiment shown, the second partition 112 is replaced with as shown Figures 11 to 12 The first intrinsic microcrystalline silicon 31 is shown. In this configuration, long-wavelength sunlight and short-wavelength ambient light are more intrinsically absorbed by the first separating region 111 and the first intrinsic microcrystalline silicon 31, while long-wavelength sunlight is less parasiticly absorbed by the P-type doped region 12. Therefore, the photoelectric conversion efficiency of the back contact photovoltaic cell 10 is relatively high.

[0071] Understandably, although the intrinsic absorption of the first intrinsic microcrystalline silicon 31 is weaker than that of the second partition region 112, the parasitic absorption of the first intrinsic microcrystalline silicon 31 is still weaker than that of the P-type doped region 12.

[0072] In some embodiments, please refer to Figure 12 As shown, the first intrinsic microcrystalline silicon 31 and the P-type doped region 12 are alternately arranged along the second direction Y, and the third partition region 113 and the N-type doped region 13 are alternately arranged along the second direction Y.

[0073] In some embodiments, please refer to Figure 13 and Figure 14 As shown, the back-contact photovoltaic cell 10 may include a second intrinsic microcrystalline silicon 32, and the second intrinsic microcrystalline silicon 32 and the N-type doped region 13 are alternately arranged along the second direction Y. This can also be understood as... Figure 1 , Figure 3 and Figure 4 Based on the embodiment shown, the third partition 113 is replaced with, as shown in the example. Figures 13 to 14The second intrinsic microcrystalline silicon 32 is shown. In this configuration, more of the long-wavelength sunlight and the short-wavelength ambient light are intrinsically absorbed by the first separating region 111 and the second intrinsic microcrystalline silicon 32, while less of the long-wavelength sunlight is parasiticly absorbed by the N-type doped region 13. Therefore, the photoelectric conversion efficiency of the back-contact photovoltaic cell 10 is relatively high.

[0074] Understandably, although the intrinsic absorption of the second intrinsic microcrystalline silicon 32 is weaker than that of the third partition region 113, the parasitic absorption of the second intrinsic microcrystalline silicon 32 is still weaker than that of the N-type doped region 13.

[0075] In some embodiments, please refer to Figure 14 As shown, the second partition region 112 and the P-type doped region 12 are alternately arranged along the second direction Y, and the second intrinsic microcrystalline silicon 32 and the N-type doped region 13 are alternately arranged along the second direction Y.

[0076] In some embodiments, please refer to Figure 15 As shown, the back-contact photovoltaic cell 10 may include a first intrinsic microcrystalline silicon 31 and a second intrinsic microcrystalline silicon 32. The first intrinsic microcrystalline silicon 31 and the P-type doped region 12 are alternately arranged along the second direction Y, and the second intrinsic microcrystalline silicon 32 and the N-type doped region 13 are alternately arranged along the second direction Y. A first separating region 111 is disposed between the P-type doped region 12 and the N-type doped region 13. The relevant technical effects have been described above and will not be repeated here.

[0077] It is understandable that the meaning of intrinsic polycrystalline silicon can include: silicon materials with a microcrystalline structure that have not undergone artificial doping treatment.

[0078] In some embodiments, please refer to Figure 1 , Figure 2 , Figure 5 , Figure 6 and Figure 11 As shown, the back-contact photovoltaic cell 10 includes a first grid line electrode 61, which is electrically connected to the P-type doped region 12. The first grid line electrode 61 can serve as the positive electrode.

[0079] In some embodiments, please refer to Figure 1 , Figure 3 , Figure 5 , Figure 8 and Figure 13 As shown, the back-contact photovoltaic cell 10 includes a second grid electrode 62, which is electrically connected to the N-type doped region 13. The second grid electrode 62 can serve as a negative electrode.

[0080] In some embodiments, please refer to Figure 1As shown, the back-contact photovoltaic cell 10 may include a first passivation structure 51, which is disposed on the second surface 1b of the silicon substrate 1. Figure 2 , Figure 3 , Figure 5 , Figure 6 , Figure 8 , Figure 11 and Figure 13 The same applies to the positional setting of the first passivation structure 51 shown.

[0081] In some embodiments, please refer to Figure 16 As shown, the back-contact photovoltaic cell 10 includes a first intrinsic amorphous silicon 41, with the first intrinsic amorphous silicon 41 and a P-type doped region 12 alternately arranged along the second direction Y. The first gate electrode 61 includes a first reflective portion 611, with at least a portion of the structure of the first intrinsic amorphous silicon 41 disposed between the first reflective portion 611 and the base region 11. In this configuration, the first reflective portion 611 can reflect some long-wavelength light that has penetrated the silicon substrate 1 and the first intrinsic amorphous silicon 41 back into the silicon substrate 1, so that the silicon substrate 1 can intrinsically absorb a relatively large amount of long-wavelength light energy, thereby resulting in a relatively high photoelectric conversion efficiency for the back-contact photovoltaic cell 10.

[0082] In some embodiments, please refer to Figure 16 As shown, the surface of the first reflective part 611 has a reflective effect on light.

[0083] In some embodiments, please refer to Figure 16 As shown, the first reflective part 611 may include silver and / or aluminum.

[0084] In some embodiments, please refer to Figure 16 As shown, the first reflective part 611 may include silver and / or copper.

[0085] In some embodiments, please refer to Figure 16 As shown, at least a portion of the structure of the first reflective portion 611 is embedded in the first intrinsic amorphous silicon 41. This can also be understood as the first intrinsic amorphous silicon 41 being provided with a first groove, and at least a portion of the structure of the first reflective portion 611 being provided in the first groove. Under this arrangement, the thickness (dimension along the sixth direction N) of the region located between the first reflective portion 611 and the base region 11 in the first intrinsic amorphous silicon 41 is relatively small, and the degree of parasitic absorption that the first intrinsic amorphous silicon 41 can generate is relatively small, so that a relatively large amount of long-wavelength light can be reflected back into the silicon substrate 1 by the first reflective portion 611.

[0086] In some embodiments, please refer to Figure 16As shown, the back-contact photovoltaic cell 10 may include a first passivation structure 51, and a portion of the first passivation structure 51 may be disposed between the first reflective portion 611 and the first intrinsic amorphous silicon 41. Since the first passivation structure 51 has light-transmitting properties, long-wavelength light that has penetrated the silicon substrate 1 can still be reflected back into the silicon substrate 1 by the first reflective portion 611.

[0087] In some other embodiments (not shown in the figures), the first intrinsic amorphous silicon and the first reflective portion can be directly connected.

[0088] In some embodiments, please refer to Figure 16 As shown, for the same first gate electrode 61, the first gate electrode 61 includes a first conductive body 612 and a plurality of first reflective parts 611 connected to each other. The plurality of first reflective parts 611 protrude from the first conductive body 612 into the interior of the first intrinsic amorphous silicon 41.

[0089] Understandably, the first reflective portion 611 serves as a substructure for conducting electricity within the first gate electrode 61.

[0090] In some embodiments, please refer to Figure 16 As shown, for the same first gate electrode 61, the first gate electrode 61 includes a first conductive body 612 and a plurality of first electrical connection portions 613 connected to each other. The plurality of first electrical connection portions 613 protrude from the first conductive body 612 into the interior of the P-type doped region 12, and the first electrical connection portions 613 are electrically connected to the P-type doped region 12.

[0091] In some embodiments, the back-contact photovoltaic cell 10 includes a plurality of first grid line electrodes 61. The first grid line electrodes 61 can serve as fine grid electrodes or sub-grid electrodes. The back-contact photovoltaic cell 10 may also include a first main grid electrode (not shown in the figure). The plurality of first grid line electrodes 61 are electrically connected to the first main grid electrode. The first main grid electrode can be electrically connected to conductive interconnect strips to form a cell string.

[0092] In some embodiments, when the grid line electrode of the back contact photovoltaic cell 10 is welded to the conductive interconnect strip, the conductive interconnect strip may also be referred to as a solder strip.

[0093] In some embodiments, the back-contact photovoltaic cell 10 includes a plurality of first grid line electrodes 61, which are electrically connected to conductive interconnects to form a cell string. It is understood that the back-contact photovoltaic cell 10 is a gridless cell.

[0094] In some embodiments, the ratio of the length (dimension along the sixth direction N) of the portion of the first reflective portion 611 embedded in the first intrinsic amorphous silicon 41 to the maximum thickness (dimension along the sixth direction N) of the first intrinsic amorphous silicon 41 can be in the range of 0.4 to 0.8. Specifically, the ratio can be 0.4, 0.5, 0.6, 0.7, or 0.8.

[0095] In other embodiments, the ratio of the length of the portion of the first reflective portion 611 embedded in the first intrinsic amorphous silicon 41 to the maximum thickness of the first intrinsic amorphous silicon 41 can also be in the range of 0.5 to 0.6. Specifically, the ratio can be 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, or 0.6.

[0096] In some embodiments, please refer to Figure 17 As shown, the back-contact photovoltaic cell 10 includes a second intrinsic amorphous silicon 42, with the second intrinsic amorphous silicon 42 and an N-type doped region 13 alternately arranged along a second direction Y. The second gate electrode 62 includes a second reflective portion 621, with at least a portion of the structure of the second intrinsic amorphous silicon 42 disposed between the second reflective portion 621 and the base region 11. In this configuration, the second reflective portion 621 can reflect some long-wavelength light that has penetrated the silicon substrate 1 and the second intrinsic amorphous silicon 42 back into the silicon substrate 1, so that the silicon substrate 1 can intrinsically absorb a relatively large amount of long-wavelength light energy, thereby resulting in a relatively high photoelectric conversion efficiency for the back-contact photovoltaic cell 10.

[0097] In some embodiments, please refer to Figure 17 As shown, the surface of the second reflective part 621 has a reflective effect on light.

[0098] In some embodiments, please refer to Figure 17 As shown, the second reflective portion 621 may include silver and / or aluminum.

[0099] In some embodiments, please refer to Figure 17 As shown, the second reflective portion 621 may include silver and / or copper.

[0100] In some embodiments, please refer to Figure 17 As shown, at least a portion of the structure of the second reflective portion 621 is embedded within the second intrinsic amorphous silicon 42. This can also be understood as the second intrinsic amorphous silicon 42 being provided with a second groove, and at least a portion of the structure of the second reflective portion 621 being disposed within the second groove. Under this arrangement, the thickness (dimension along the sixth direction N) of the region located between the second reflective portion 621 and the base region 11 within the second intrinsic amorphous silicon 42 is relatively small, and the degree of parasitic absorption generated by the second intrinsic amorphous silicon 42 is relatively small, so that a relatively large amount of long-wavelength light can be reflected back into the silicon substrate 1 by the second reflective portion 621.

[0101] In some embodiments, please refer to Figure 17 As shown, the back-contact photovoltaic cell 10 may include a first passivation structure 51, and a portion of the first passivation structure 51 may be disposed between the second reflective portion 621 and the second intrinsic amorphous silicon 42. Since the first passivation structure 51 has light-transmitting properties, long-wavelength light that has penetrated the silicon substrate 1 can still be reflected back into the silicon substrate 1 by the second reflective portion 621.

[0102] In some other embodiments (not shown in the figures), the second intrinsic amorphous silicon and the second reflective portion can be directly connected.

[0103] In some embodiments, please refer to Figure 17 As shown, for the same second gate electrode 62, the second gate electrode 62 includes a second conductive body 622 and a plurality of second reflective parts 621 connected to each other. The plurality of second reflective parts 621 protrude from the second conductive body 622 into the interior of the second intrinsic amorphous silicon 42.

[0104] Understandably, the second reflector 621 serves as a substructure for conduction within the second gate electrode 62.

[0105] In some embodiments, please refer to Figure 17 As shown, for the same second gate electrode 62, the second gate electrode 62 includes a second conductive body 622 connected to each other and a plurality of second electrical connection portions 623. The plurality of second electrical connection portions 623 protrude from the second conductive body 622 into the interior of the N-type doped region 13, and the second electrical connection portions 623 are electrically connected to the N-type doped region 13.

[0106] In some embodiments, the back-contact photovoltaic cell 10 includes a plurality of second grid line electrodes 62. The second grid line electrodes 62 can serve as fine grid electrodes or sub-grid electrodes. The back-contact photovoltaic cell 10 may also include a second main grid electrode (not shown in the figure). The plurality of second grid line electrodes 62 are electrically connected to the second main grid electrode. The second main grid electrode can be electrically connected to conductive interconnect strips to form a cell string.

[0107] In some embodiments, the back-contact photovoltaic cell 10 includes a plurality of second grid electrodes 62, which are electrically connected to conductive interconnects to form a cell string. It is understood that the back-contact photovoltaic cell 10 is a gridless cell.

[0108] In some embodiments, the ratio of the length (dimension along the sixth direction N) of the portion of the second reflective portion 621 embedded in the second intrinsic amorphous silicon 42 to the maximum thickness (dimension along the sixth direction N) of the second intrinsic amorphous silicon 42 can be in the range of 0.4 to 0.8. Specifically, the ratio can be 0.4, 0.5, 0.6, 0.7, or 0.8.

[0109] In other embodiments, the ratio of the length of the portion of the second reflective portion 621 embedded in the second intrinsic amorphous silicon 42 to the maximum thickness of the second intrinsic amorphous silicon 42 can also be in the range of 0.5 to 0.6. Specifically, the ratio can be 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, or 0.6.

[0110] In some embodiments, please refer to Figure 18 As shown, the back-contact photovoltaic cell 10 may include a third intrinsic amorphous silicon 43 and a first metal reflective layer 71. The third intrinsic amorphous silicon 43 and the P-type doped region 12 are alternately arranged along the second direction Y. At least a portion of the structure of the third intrinsic amorphous silicon 43 is disposed between the first metal reflective layer 71 and the base region 11. In this arrangement, the first metal reflective layer 71 can reflect some long-wavelength light that has penetrated the silicon substrate 1 and the third intrinsic amorphous silicon 43 back into the silicon substrate 1, so that the silicon substrate 1 can intrinsically absorb a relatively large amount of long-wavelength light energy, thereby resulting in a relatively high photoelectric conversion efficiency of the back-contact photovoltaic cell 10.

[0111] In some embodiments, please refer to Figure 18 As shown, the main function is to utilize the reflection effect of the surface of the first metal reflective layer 71 facing the base region 11.

[0112] In some embodiments, please refer to Figure 18 As shown, the surface roughness Ra (profile arithmetic mean deviation) of the first metal reflective layer 71 facing the base region 11 can be below 5 nm, so that the surface of the first metal reflective layer 71 facing the base region 11 has good light reflection.

[0113] In some embodiments, please refer to Figure 18 As shown, the first metal reflective layer 71 may include copper, nickel, or a copper-nickel alloy.

[0114] In some embodiments, please refer to Figure 18 As shown, the first metal reflective layer 71 can be prepared by atomic layer deposition (ALD) or physical vapor deposition (PVD).

[0115] In some embodiments, please refer to Figure 18 As shown, at least a part of the structure of the first metal reflection layer 71 is embedded in the third intrinsic amorphous silicon 43. It can also be understood that the third intrinsic amorphous silicon 43 is provided with a third groove, and at least a part of the structure of the first metal reflection layer 71 is disposed in the third groove. In this setting, the thickness (dimension along the sixth direction N) of the region in the third intrinsic amorphous silicon 43 located between the first metal reflection layer 71 and the base region 11 is relatively small, and the degree of parasitic absorption generated by the third intrinsic amorphous silicon 43 is relatively small, so that a relatively large amount of long-wavelength light can be reflected back into the silicon substrate 1 by the first metal reflection layer 71.

[0116] In some embodiments, please refer to Figure 18 As shown, the cross-sectional structure of the first metal reflection layer 71 can be in the shape of "冂" or "凵", or the cross-sectional structure of the first metal reflection layer 71 is approximately in the shape of "冂" or "凵". It can also be understood that the first metal reflection layer 71 deposited on the third groove forms a fourth groove.

[0117] In some embodiments, please refer to Figure 18 As shown, the back-contact photovoltaic cell 10 can include a first passivation structure 51, and a partial structure of the first passivation structure 51 can be disposed between the first metal reflection layer 71 and the third intrinsic amorphous silicon 43. Since the first passivation structure 51 has a light-transmitting property, the long-wavelength light that has penetrated the silicon substrate 1 can still be reflected back into the silicon substrate 1 by the first metal reflection layer 71.

[0118] In some other embodiments (not shown in the figure), the first metal reflection layer and the third intrinsic amorphous silicon can be directly connected.

[0119] In some embodiments, the first metal reflection layer 71 and the first gate electrode 61 may not be directly connected, that is, the first metal reflection layer 71 is not used for conduction.

[0120] In some other embodiments, the first metal reflection layer 71 and the first gate electrode 61 can be directly connected.

[0121] In some embodiments, please refer to Figure 19 As shown, the back-contact photovoltaic cell 10 can include a fourth intrinsic amorphous silicon 44 and a second metal reflection layer 72. The fourth intrinsic amorphous silicon 44 and the N-type doped region 13 are alternately arranged along the second direction Y, and at least a part of the structure of the fourth intrinsic amorphous silicon 44 is disposed between the second metal reflection layer 72 and the base region 11. In this setting, the second metal reflection layer 72 can reflect some of the long-wavelength light that has penetrated the silicon substrate 1 and the fourth intrinsic amorphous silicon 44 back into the silicon substrate 1, so that the energy of the long-wavelength light that can be intrinsically absorbed by the silicon substrate 1 is relatively large, and thus the photoelectric conversion efficiency of the back-contact photovoltaic cell 10 is relatively large.

[0122] In some embodiments, please refer to Figure 19 As shown, the reflection effect of the surface of the second metal reflection layer 72 facing the base region 11 is mainly utilized.

[0123] In some embodiments, please refer to Figure 19 As shown, the surface roughness Ra of the surface of the second metal reflection layer 72 facing the base region 11 can be below 5 nm, so that the surface of the second metal reflection layer 72 facing the base region 11 has a good reflection effect on light.

[0124] In some embodiments, please refer to Figure 19 As shown, the second metal reflection layer 72 can include copper, nickel or a copper-nickel alloy.

[0125] In some embodiments, please refer to Figure 19 As shown, the second metal reflection layer 72 can be prepared by atomic layer deposition or physical vapor deposition.

[0126] In some embodiments, please refer to Figure 19 As shown, at least part of the structure of the second metal reflection layer 72 is embedded in the fourth intrinsic amorphous silicon 44. It can also be understood that the fourth intrinsic amorphous silicon 44 is provided with a fifth groove, and at least part of the structure of the second metal reflection layer 72 is disposed in the fifth groove. In this setting, the thickness (dimension along the sixth direction N) of the region of the fourth intrinsic amorphous silicon 44 between the second metal reflection layer 72 and the base region 11 is relatively small, and the degree of parasitic absorption generated by the fourth intrinsic amorphous silicon 44 is relatively small, so that relatively more long-wavelength light can be reflected back into the silicon substrate 1 by the second metal reflection layer 72.

[0127] In some embodiments, please refer to Figure 19 As shown, the cross-sectional structure of the second metal reflection layer 72 can be in a "冂" shape or a "凵" shape, or the cross-sectional structure of the second metal reflection layer 72 is approximately in a "冂" shape or a "凵" shape. It can also be understood that the second metal reflection layer 72 deposited on the fifth groove forms a sixth groove.

[0128] In some embodiments, please refer to Figure 19 As shown, the back-contact photovoltaic cell 10 can include a first passivation structure 51, and a partial structure of the first passivation structure 51 can be disposed between the second metal reflection layer 72 and the fourth intrinsic amorphous silicon 44. Since the first passivation structure 51 has a light-transmissive property, the long-wavelength light that has penetrated the silicon substrate 1 can still be reflected back into the silicon substrate 1 by the second metal reflection layer 72.

[0129] In some other embodiments (not shown in the figure), the second metal reflection layer and the fourth intrinsic amorphous silicon can be directly connected.

[0130] In some embodiments, the second metal reflective layer 72 and the second gate electrode 62 may not be directly connected, that is, the second metal reflective layer 72 is not used for conducting electricity.

[0131] In some other embodiments, the second metal reflective layer 72 can be directly connected to the second gate electrode 62.

[0132] It is understandable that the meaning of intrinsic amorphous silicon can include: silicon materials with an amorphous structure that have not undergone artificial doping treatment.

[0133] In some embodiments, please refer to Figures 20 to 21 As shown, the P-type doped region 12 has a first area, and the N-type doped region 13 has a second area, with the first area being smaller than the second area. It can be understood that the first area is the area of ​​the projection of the P-type doped region 12 along the sixth direction N onto the base region 11, and the second area is the area of ​​the projection of the N-type doped region 13 along the sixth direction N onto the base region 11. The P-type doped region 12 has a first depth H1 along the sixth direction N, and the N-type doped region 13 has a second depth H2 along the sixth direction N, with the first depth H1 being greater than the second depth H2. Under this configuration, given the good hole collection capability of the P-type doped region 12, the parasitic absorption of long-wavelength sunlight by the P-type doped region 12 is relatively small.

[0134] Understandably, the parasitic absorption of the P-type doped region 12 is weaker than that of the N-type doped region 13. Therefore, reducing the parasitic absorption of the P-type doped region 12 is more conducive to improving the photoelectric conversion efficiency of the back contact photovoltaic cell 10.

[0135] Understandably, the measurement of the first depth H1 of the P-type doped region 12 and the second depth H2 of the N-type doped region 13 can be performed using the ECV analysis method and ECV instrument mentioned above to obtain information on the distribution of activation doping concentration with depth. In addition, the measurement of the first depth H1 of the P-type doped region 12 and the second depth H2 of the N-type doped region 13 can also be performed using secondary ion mass spectrometry (SIMS) and a secondary ion mass spectrometer (SIMS instrument) to obtain information on the distribution of doping concentration with depth.

[0136] Understandably, the measurement of the first area of ​​the P-type doped region 12 and the second area of ​​the N-type doped region 13 can be achieved by observing the difference in brightness between the doped region and the base region 11 using a high-magnification optical microscope (due to variations in reflectivity caused by different dopant element types and concentrations). This can then be combined with image processing software for threshold segmentation and edge recognition to automatically calculate the area. Alternatively, the sheet resistance of the doped region can be measured using the four-probe method. Sheet resistance is negatively correlated with doping concentration; by measuring the sheet resistance at multiple points, a sheet resistance distribution map can be constructed, and the area of ​​the doped region can be deduced using a diffusion model. Furthermore, the area of ​​the doped region can also be measured using photoluminescence imaging.

[0137] In some embodiments, please refer to Figures 20 to 21 As shown, the P-type doped region 12 is electrically connected to the first gate electrode 61, and the N-type doped region 13 is electrically connected to the second gate electrode 62. A first connection area exists between the P-type doped region 12 and the first gate electrode 61, and a second connection area exists between the N-type doped region 13 and the second gate electrode 62. The first connection area is larger than the second connection area. With this configuration, given the relatively small area of ​​the P-type doped region 12, the contact resistance between the P-type doped region 12 and the first gate electrode 61 is low, resulting in relatively low current loss during current transmission.

[0138] In some embodiments, please refer to Figures 20 to 21 As shown, the first gate electrode 61 includes a first electrical connection portion 613. For some P-type doped regions 12, the same P-type doped region 12 is electrically connected to at least two first electrical connection portions 613. The second gate electrode 62 includes a second electrical connection portion 623. For some N-type doped regions 13, the same N-type doped region 13 is electrically connected to at least three second electrical connection portions 623. The average length (dimension along the sixth direction N) of the first electrical connection portion 613 is greater than the average length (dimension along the sixth direction N) of the second electrical connection portion 623, to satisfy the setting that "the first connection area between the P-type doped region 12 and the first gate electrode 61 is greater than the second connection area between the N-type doped region 13 and the second gate electrode 62".

[0139] In some embodiments, please refer to Figures 20 to 21 As shown, the first gate electrode 61 includes a first conductive body 612, which is connected to a first electrical connection portion 613. The second gate electrode 62 includes a second conductive body 622, which is connected to a second electrical connection portion 623.

[0140] In some other embodiments (not shown in the figures), the back-contact photovoltaic cell includes a silicon substrate. The silicon substrate includes a base region, at least two P-type doped regions, and at least two N-type doped regions. The P-type and N-type doped regions are spaced apart along a first direction. The base region includes a first partition region disposed between the P-type and N-type doped regions. The at least two P-type doped regions are spaced apart along a second direction, and the at least two N-type doped regions are spaced apart along the second direction. Both the P-type and N-type doped regions protrude relative to the base region. For the two P-type doped regions spaced apart in the second direction, there is a seventh groove between the two P-type doped regions. For the two N-type doped regions spaced apart in the second direction, there is an eighth groove between the two N-type doped regions. A partial structure of the first passivation structure is disposed on the seventh groove, and other partial structures of the first passivation structure are disposed on the eighth groove. It can be understood that a ninth groove is formed at the location where the first passivation structure is deposited on the seventh groove, and a tenth groove is formed at the location where the first passivation structure is deposited on the eighth groove.

[0141] In some embodiments, the first passivation structure 51 may include at least one of a silicon oxide layer, an aluminum oxide layer, a silicon nitride layer, and a silicon oxynitride layer.

[0142] In some embodiments, please refer to Figure 1 As shown, the back contact photovoltaic cell 10 also includes a second passivation structure 52, which is disposed on the first surface 1a. The second passivation structure 52 may include at least one of a silicon oxide layer, an aluminum oxide layer, a silicon nitride layer, and a silicon oxynitride layer.

[0143] In some embodiments, please refer to Figure 1 As shown, the first surface 1a of the silicon substrate 1 may include a textured surface, or it can be understood that the first surface 1a of the silicon substrate 1 includes multiple pyramids, so that the first surface 1a has a light trapping effect, that is, the light reflectivity of the first surface 1a is relatively low, and a relatively large amount of sunlight can be incident into the silicon substrate 1 per unit time.

[0144] In some other embodiments, the silicon substrate 1 may be a P-type silicon substrate, meaning that the base region 11 may be doped with at least one P-type element. Accordingly, the active doping concentration of the P-type doped region 12 with respect to the P-type element is greater than the active doping concentration of the base region 11 with respect to the P-type element.

[0145] In some other embodiments (not shown in the figures), the P-type doped region can be replaced by a P-type tunneling passivation contact structure, which includes a first tunneling layer and a P-type doped conductive layer, the first tunneling layer being disposed between the silicon substrate and the P-type doped conductive layer. The first tunneling layer may include at least one of silicon oxide, silicon oxynitride, aluminum oxide, silicon nitride, intrinsic amorphous silicon, and intrinsic polycrystalline silicon. Additionally, the P-type doped conductive layer may include at least one of polycrystalline silicon, amorphous silicon, and microcrystalline silicon, and is doped with at least one P-type element. It is understood that the P-type tunneling passivation contact structure is a structure other than a silicon substrate.

[0146] In some other embodiments (not shown in the figures), the N-type doped region can be replaced by an N-type tunneling passivation contact structure, which includes a second tunneling layer and an N-type doped conductive layer, the second tunneling layer being disposed between the silicon substrate and the N-type doped conductive layer. The second tunneling layer may include at least one of silicon oxide, silicon oxynitride, aluminum oxide, silicon nitride, intrinsic amorphous silicon, and intrinsic polycrystalline silicon. Additionally, the N-type doped conductive layer may include at least one of polycrystalline silicon, amorphous silicon, and microcrystalline silicon, and is doped with at least one N-type element. It is understood that the N-type tunneling passivation contact structure is a structure other than a silicon substrate.

[0147] Understandably, microscopic instruments such as scanning electron microscopes (SEM), atomic force microscopes (AFM), or transmission electron microscopes (TEM) can be used to obtain sample images of the local structure of the back-contact photovoltaic cell 10. The dimensions and shapes of the microstructures in the sample images can be measured. The measured dimensions and areas can be averaged from measurements of the structures in multiple sample images.

[0148] This application provides some embodiments of photovoltaic (PV) modules, which may include cell strings, each comprising a conductive connection strip and at least two PV cells. Within the same cell string, for two adjacent PV cells, one PV cell is electrically connected to the other via a conductive connection strip (CCS). The PV cells may employ the back-contact PV cell 10 described above, thus resulting in a relatively high output power for the PV module.

[0149] In some embodiments, a photovoltaic module may include at least two battery strings, which may be electrically connected in series or in parallel.

[0150] In some embodiments, when the grid electrodes of a photovoltaic cell are welded to conductive interconnects, the conductive interconnects may also be referred to as solder strips.

[0151] In some other embodiments, the grid electrodes of the photovoltaic cell can also be connected to the conductive interconnects using conductive adhesive.

[0152] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application, or the scope of this application should be defined by the appended claims.

Claims

1. A back-contact photovoltaic cell, characterized in that, The back-contact photovoltaic cell includes a silicon substrate, the silicon substrate including a base region, at least two P-type doped regions and at least two N-type doped regions, the P-type doped regions and the N-type doped regions being spaced apart along a first direction, the base region including a first separating region being disposed between the P-type doped regions and the N-type doped regions, the at least two P-type doped regions being spaced apart along a second direction, the at least two N-type doped regions being spaced apart along the second direction, and the first direction intersecting the second direction.

2. The back-contact photovoltaic cell according to claim 1, characterized in that, The base region further includes a second partition region, the second partition region and the P-type doped region being alternately arranged along the second direction, and / or, the base region further includes a third partition region, the third partition region and the N-type doped region being alternately arranged along the second direction.

3. The back-contact photovoltaic cell according to claim 1, characterized in that, The back contact photovoltaic cell further includes a first intrinsic polycrystalline silicon, wherein the first intrinsic polycrystalline silicon and the P-type doped region are alternately arranged along a second direction, and / or, the back contact photovoltaic cell further includes a second intrinsic polycrystalline silicon, wherein the second intrinsic polycrystalline silicon and the N-type doped region are alternately arranged along the second direction.

4. The back-contact photovoltaic cell according to claim 1, characterized in that, The back contact photovoltaic cell further includes a first intrinsic microcrystalline silicon, wherein the first intrinsic microcrystalline silicon and the P-type doped region are alternately arranged along a second direction, and / or, the back contact photovoltaic cell further includes a second intrinsic microcrystalline silicon, wherein the second intrinsic microcrystalline silicon and the N-type doped region are alternately arranged along the second direction.

5. The back-contact photovoltaic cell according to claim 1, characterized in that, The back-contact photovoltaic cell includes (a): the back-contact photovoltaic cell includes a first intrinsic amorphous silicon and a first gate electrode, the first intrinsic amorphous silicon and the P-type doped region are alternately arranged along the second direction, the first gate electrode is electrically connected to the P-type doped region, the first gate electrode includes a first reflective portion, and at least a portion of the structure of the first intrinsic amorphous silicon is disposed between the first reflective portion and the base region; And / or, the back contact photovoltaic cell includes a configuration (b): the back contact photovoltaic cell includes a second intrinsic amorphous silicon and a second gate electrode, the second intrinsic amorphous silicon and the N-type doped region are alternately disposed along the second direction, the second gate electrode is electrically connected to the N-type doped region, the second gate electrode includes a second reflective portion, and at least a portion of the structure of the second intrinsic amorphous silicon is disposed between the second reflective portion and the base region.

6. The back-contact photovoltaic cell according to claim 5, characterized in that, When the back-contact photovoltaic cell includes the aforementioned arrangement (a), at least a portion of the structure of the first reflective portion is embedded within the first intrinsic amorphous silicon. And / or, when the back-contact photovoltaic cell includes the arrangement (b): at least a portion of the structure of the second reflective portion is embedded in the second intrinsic amorphous silicon.

7. The back-contact photovoltaic cell according to claim 1, characterized in that, The back-contact photovoltaic cell includes a third intrinsic amorphous silicon and a first metal reflective layer. The third intrinsic amorphous silicon and the P-type doped region are alternately arranged along the second direction. At least a portion of the structure of the third intrinsic amorphous silicon is disposed between the first metal reflective layer and the base region. And / or, the back-contact photovoltaic cell includes a fourth intrinsic amorphous silicon and a second metal reflective layer, wherein the fourth intrinsic amorphous silicon and the N-type doped region are alternately disposed along the second direction, and at least a portion of the structure of the fourth intrinsic amorphous silicon is disposed between the second metal reflective layer and the base region.

8. The back-contact photovoltaic cell according to any one of claims 1 to 7, characterized in that, The P-type doped region has a first area, the N-type doped region has a second area, the first area is smaller than the second area, the P-type doped region has a first depth, the N-type doped region has a second depth, and the first depth is greater than the second depth.

9. The back-contact photovoltaic cell according to claim 8, characterized in that, The back-contact photovoltaic cell further includes a first grid electrode and a second grid electrode. The P-type doped region is electrically connected to the first grid electrode, and the N-type doped region is electrically connected to the second grid electrode. There is a first connection area between the P-type doped region and the first grid electrode, and there is a second connection area between the N-type doped region and the second grid electrode. The first connection area is larger than the second connection area.

10. A photovoltaic module, characterized in that, The photovoltaic module includes a battery string, the battery string including at least two electrically connected photovoltaic cells, the photovoltaic cells being back-contact photovoltaic cells as described in any one of claims 1 to 9.

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