Solar cell, photovoltaic module and laminated cell

Abstract

The invention relates to the technical field of photovoltaic cells, in particular to a solar cell, a photovoltaic module and a laminated cell. The solar cell comprises a silicon substrate, the silicon substrate is provided with a first surface and a second surface which are oppositely arranged, and a plurality of first doped layers and a plurality of second doped layers are arranged on the first surface at intervals. A concave part is arranged in the first doped layer, a doped contact part with the polarity opposite to that of the first doped layer is formed in the concave part, and the first doped layer is in contact with the doped contact part. According to the invention, the first doped layer is provided with the recessed part, the recessed part is internally provided with the doped contact part, and the polarity of the doped contact part is opposite to that of the first doped layer, so that the first doped layer and the doped contact part form a local conductive path, and a bypass point location is formed at the recessed part. The reverse breakdown voltage when the back contact cell is shielded can be reduced, so that the hot spot resistance of the solar cell is improved, and the hot spot phenomenon caused by poor local conductivity of the solar cell is improved.

Description

Technical Field

[0001] This application relates to the technical field of photovoltaic cells, and particularly to a solar cell, a photovoltaic module, and a tandem cell. Background Art

[0002] Currently, in solar cells, a back-contact cell is a cell in which both the emitter and base contact electrodes are placed on the back surface (non-light-receiving surface) of the cell. There is no metal electrode shielding on the light-receiving surface of this cell, thus effectively increasing the short-circuit current of the cell.

[0003] During the use of back-contact cells, when the cell is blocked by an obstacle in the external environment, the blocked cell will exhibit a hot spot phenomenon. This effect can severely damage the solar cell, and at the same time, the energy generated by the illuminated solar cell may also be consumed by the shielded cell. Summary of the Invention

[0004] Embodiments of this application provide a solar cell, a photovoltaic module, and a tandem cell, aiming to improve the hot spot effect of solar cells.

[0005] Embodiments of this application provide a solar cell, the solar cell includes a silicon substrate, the silicon substrate has a first surface and a second surface arranged opposite to each other, and a plurality of first doping layers and a plurality of second doping layers are arranged at intervals on the first surface; A recessed portion is provided in the first doping layer, and a doping contact portion having a polarity opposite to that of the first doping layer is formed in the recessed portion, and the first doping layer is in contact with the doping contact portion.

[0006] In a possible design, there is a spacer region between the first doping layer and the second doping layer; The minimum distance between the doping contact portion and the second doping layer is the width of the spacer region.

[0007] In a possible design, the area ratio of the recessed portion to the first doping layer is a, and 0.05% ≤ a ≤ 5%.

[0008] In a possible design, the one-dimensional dimension of the recessed portion is b, and 0.5 μm ≤ b ≤ 240 μm In a possible design, the solar cell further includes a first electrode stacked on the first doping layer; Along the thickness direction of the solar cell, the projection plane of the doping contact portion on the first surface does not coincide with the projection plane of the first electrode on the first surface.

[0009] In a possible design, the doping contact portions are uniformly distributed in the first doping layer.

[0010] In a possible design, along the thickness direction perpendicular to the solar cell, the doped contact portion covers at least a partial area of the side wall of the recessed portion.

[0011] In a possible design, the recessed portion does not penetrate the first doped layer, and the doped contact portion covers the bottom wall of the recessed portion.

[0012] In a possible design, the recessed portion penetrates the first doped layer, and part of the silicon substrate is exposed from the recessed portion; The doped contact portion covers the silicon substrate exposed from the recessed portion.

[0013] In a second aspect of the embodiments of the present application, a photovoltaic module is further provided. The photovoltaic module includes a first cover plate, a first encapsulant film, a battery string, a second encapsulant film, and a second cover plate which are stacked.

[0014] The battery string includes a plurality of electrically connected solar cells, and the solar cells are the above-mentioned solar cells.

[0015] In a third aspect of the embodiments of the present application, a tandem cell is further provided. The tandem cell includes a top cell, an intermediate connection layer, and a bottom cell, and the intermediate connection layer is connected between the top cell and the bottom cell; The top cell is one of a perovskite cell, a cadmium telluride solar cell, a copper indium gallium selenide solar cell, or a gallium arsenide solar cell, and the bottom cell is the above-mentioned solar cell.

[0016] The technical effect of the embodiments of the present application is that: a recessed portion is formed in the first doped layer, a doped contact portion is provided in the recessed portion, and the polarity of the doped contact portion is opposite to the polarity of the first doped layer, so that a local conductive path is formed between the first doped layer and the doped contact portion, thereby forming a bypass point at the recessed portion, which can reduce the reverse breakdown voltage when the back contact cell is shaded, thereby improving the anti-thermal spot performance of the solar cell and realizing the improvement of the thermal spot phenomenon caused by local poor conductivity of the solar cell.

[0017] It should be understood that the above general description and the following detailed description are only exemplary and do not limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the photovoltaic module provided by the present application; Figure 2 is a schematic cross-sectional view of the solar cell provided by the present application; Figure 3 is a schematic distribution diagram of the first doped layer and the second doped layer provided by the present application; Figure 4Schematic diagram of the distribution of the doped contact portions on the first doped layer provided by this application; Figure 5 Schematic diagram of the distribution of the doped contact portions on the first doped layer provided by this application in another embodiment; Figure 6 Cross-sectional schematic diagram of a partial structure of the solar cell provided by this application; Figure 7 Cross-sectional schematic diagram of a partial structure of the solar cell provided by this application in another embodiment; Figure 8 Cross-sectional schematic diagram of a partial structure of the solar cell provided by this application in another embodiment; Figure 9 Cross-sectional schematic diagram of a partial structure of the solar cell provided by this application in another embodiment; Figure 10 Cross-sectional schematic diagram of a partial structure of the solar cell provided by this application in another embodiment.

[0019] Reference numerals: 10 - Photovoltaic module; 101 - First cover plate; 102 - First encapsulant film; 103 - Cell string; 104 - Second encapsulant film; 105 - Second cover plate; 1 - Solar cell; 11 - Silicon substrate; 11a - First surface; 11b - Second surface; 111 - First doped layer; 111a - Concave portion; 111b - Doped contact portion; 112 - Second doped layer; 113 - Spacer region; 114 - First electrode; 115 - Second electrode; 116 - Tunneling oxide layer; 117 - Back surface passivation layer; 118 - Front surface passivation layer.

[0020] The accompanying drawings here are incorporated into the specification and form a part of the specification, showing embodiments consistent with this application, and are used together with the specification to explain the principles of this application. Detailed implementation manners

[0021] For a better understanding of the technical solutions of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0022] It should be clear that the described embodiments are only a part of the embodiments of the present application, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts belong to the scope protected by the present application.

[0023] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0024] It should be understood that the term "and / or" used herein is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0025] It should be noted that the orientation terms such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described from the angles shown in the drawings and should not be construed as a limitation on the embodiments of the present application. In addition, in the context, it should also be understood that when it is mentioned that an element is connected "above" or "below" another element, it can not only be directly connected "above" or "below" another element, but also be indirectly connected "above" or "below" another element through an intermediate element.

[0026] In the field of photovoltaic power generation technology, a photovoltaic module is the core component that converts solar energy into electrical energy. Figure 1 FIG. 16 is a schematic structural diagram of a photovoltaic module 10. The photovoltaic module 10 includes a first cover plate 101, a first encapsulant film 102, a cell string 103, a second encapsulant film 104, and a second cover plate 105 that are stacked along the Z direction of its own thickness. The first cover plate 101 and the cell string 103 are encapsulated and fixed through the first encapsulant film 102, and the second cover plate 105 and the cell string 103 are encapsulated and fixed through the second encapsulant film 104.

[0027] Specifically, the first cover plate 101 and / or the second cover plate 105 can be photovoltaic glass with a high light transmittance, such as double-coated glass. The first cover plate 101 and the second cover plate 105 are used to protect the internal encapsulant materials and the cell string 103 from mechanical damage and external environmental erosion and have the ability to prevent water and moisture. During the lamination process of the photovoltaic module 10, the first encapsulant film 102 and the second encapsulant film 104 are used to encapsulate the cell string 103 to prevent the external environment from affecting the performance of the cell string 103, and at the same time, they can also bond the first cover plate 101, the cell string 103, and the second cover plate 105 into a whole.

[0028] Among them, the battery string 103 can be one or multiple. When there are multiple battery strings 103, they can be connected in series, parallel, or in a mixed connection. A mixed connection means that there are both series and parallel connections among multiple battery strings 103, which can provide a relatively high voltage and capacity. One end of the bus bar is connected to the battery string 103, and the other end is connected to the junction box, so as to lead out the electric energy generated by the photovoltaic module 10 through the junction box and connect it to an external load.

[0029] Among them, the materials of the first encapsulant film 102 and the second encapsulant film 104 can be one of materials such as ethylene-vinyl acetate copolymer (EVA), polyolefin elastomer (POE), polyvinyl butyral (PVB), etc., and can also be an EPE encapsulant film (EVA-POE-EVA co-extrusion structure) or an EP encapsulant film (EVA-EP co-extrusion structure).

[0030] It can be understood that other layers can also be provided between the first cover plate 101 and the first encapsulant film 102, between the first encapsulant film 102 and the battery string 103, between the battery string 103 and the second encapsulant film 104, and between the second encapsulant film 104 and the second cover plate 105. Here, the specific number of layers of the photovoltaic module 10 can be set according to the actual situation, and this embodiment does not limit it here.

[0031] In this embodiment, the photovoltaic module 10 strings and connects the single solar cells 1, encapsulates them, and connects out the external connecting wires, becoming a solar cell 1 module that can be independently used as a photovoltaic power source. The photovoltaic module 10 absorbs sunlight and directly converts solar radiant energy into electric energy output required by using the photovoltaic effect.

[0032] Figure 2 It is a cross-sectional schematic diagram of the solar cell 1. The solar cell 1 includes a silicon substrate 11. Along the thickness direction Z of the solar cell 1, the silicon substrate 11 has a first surface 11a and a second surface 11b that are oppositely arranged.

[0033] In some embodiments, the material of the silicon substrate 11 can be an elemental semiconductor material. Specifically, the elemental semiconductor material is composed of a single element, for example, it can be silicon. Among them, the elemental semiconductor material can be in a single crystal state, polycrystalline state, amorphous state, or microcrystalline state (a state with both single crystal state and amorphous state is called microcrystalline state). For example, silicon can be at least one of single crystal silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon.

[0034] In some embodiments, the silicon substrate 11 can be an N-type semiconductor substrate or a P-type semiconductor substrate. The N-type semiconductor substrate is doped with an N-type element, and the N-type element can be any one of group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As). The P-type semiconductor substrate is doped with a P-type element, and the P-type doping element can be any one of group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0035] In some embodiments, the first surface 11a of the silicon substrate 11 can be the back surface, and the second surface 11b can be the front surface. When the solar cell 1 is a single-sided cell, the second surface 11b can be the light-receiving surface for receiving incident light, and the first surface 11a serves as the backlight surface. When the solar cell 1 is a double-sided cell, that is, both the first surface 11a and the second surface 11b of the silicon substrate 11 can be used as light-receiving surfaces and can be used to receive incident light. Among them, the first surface 11a can also receive incident light, but the efficiency of receiving incident light is slightly lower than that of the second surface 11b receiving incident light.

[0036] Among them, the second surface 11b has a textured surface structure, and the textured surface structure is a regular pyramid-shaped textured surface structure. The inclined surface of the textured surface structure can increase the internal reflection of incident light, thereby improving the absorption and utilization rate of the silicon substrate 11 for incident light, and further improving the cell efficiency of the solar cell 1.

[0037] Please continue to refer to Figure 2 , a tunneling oxide layer 116 is provided on the side of the first surface 11a away from the silicon substrate 11, and a plurality of first doping layers 111 and second doping layers 112 are provided at intervals on the side of the tunneling oxide layer 116 away from the silicon substrate 11, and there is a spacer region 113 between the first doping layer 111 and the second doping layer 112. A back surface passivation layer 117 is provided on the side of the first doping layer 111 away from the silicon substrate 11, the side of the second doping layer 112 away from the silicon substrate 11, and the spacer region 113. The first surface 11a is also provided with a first electrode 114 and a second electrode 115. A partial structure of the first electrode 114 penetrates the back surface passivation layer 117 and is electrically connected to the first doping layer 111, and a partial structure of the second electrode 115 penetrates the back surface passivation layer 117 and is electrically connected to the second doping layer 112.

[0038] Among them, the first electrode 114 and the second electrode 115 are the fine grids of the solar cell 1 for collecting and aggregating the current of the solar cell 1, and the first electrode 114 and the second electrode 115 can be sintered from burn-through paste.

[0039] Specifically, the forming methods of the first electrode 114 and the second electrode 115 can be as follows: Metal paste is printed on the surface of the back passivation layer 117 by using a screen printing process, and then a sintering process is performed on the metal paste. The metal paste contains materials with glass powder or highly corrosive components. In this way, during the sintering process, the corrosive components will corrode the back passivation layer 117, so that the metal paste penetrates into the back passivation layer 117 and is in electrical contact with the first doping layer 111 or the second doping layer 112.

[0040] Among them, the metal paste can include at least one of silver, aluminum, copper, tin, gold, lead or nickel.

[0041] Please continue to refer to Figure 2 , and a front passivation layer 118 is provided on the side of the second surface 11b facing away from the silicon substrate 11.

[0042] Figure 3 FIG. is a schematic diagram of the distribution of the first doping layer 111 and the second doping layer 112. There is a spacer 113 between the first doping layer 111 and the second doping layer 112 to achieve automatic isolation between regions of different conduction types, and it can eliminate leakage caused by the formation of a tunnel junction between the heavily doped P region and the N region on the back of the solar cell 1, which affects the cell efficiency. Moreover, the first doping layer 111 is electrically connected to the first electrode 114, and the second doping layer 112 is electrically connected to the second electrode 115.

[0043] It can be understood that the first doping layer 111 can be an N-type doping layer, and the second doping layer 112 can be a P-type doping layer. Or, the first doping layer 111 can be a P-type doping layer, and the second doping layer 112 can be an N-type doping layer. It can be specifically set according to the actual situation, as long as the polarities of the first doping layer 111 and the second doping layer 112 are opposite. This embodiment does not make a limitation here.

[0044] Figure 4 FIG. is a schematic diagram of the distribution of the doping contact part 111b on the first doping layer 111 in one embodiment. Figure 5 FIG. is a schematic diagram of the distribution of the doping contact part 111b on the first doping layer 111 in another embodiment. Please refer to Figure 4 and Figure 5 , a recess 111a is provided in the first doping layer 111, and a doping contact part 111b with a polarity opposite to that of the first doping layer 111 is formed in the recess 111a, and the first doping layer 111 is in contact with the doping contact part 111b.

[0045] Among them, the recessed portion 111a may be a groove structure formed in the first doped layer 111, that is, along the thickness direction Z of the solar cell 1, the recessed portion 111a does not completely penetrate the first doped layer 111. Alternatively, the recessed portion 111a may also be a hole structure formed in the first doped layer 111, that is, along the thickness direction Z of the solar cell 1, the recessed portion 111a completely penetrates the first doped layer 111. It can be specifically set according to the actual situation, and this embodiment does not limit it here.

[0046] In this embodiment, a recessed portion 111a is formed on the first doped layer 111. The recessed portion 111a has a doped contact portion 111b, and the polarity of the doped contact portion 111b is opposite to that of the first doped layer 111, so that the first doped layer 111 and the doped contact portion 111b are in contact to form a local conduction path, thereby forming a bypass point at the recessed portion 111a, which can reduce the reverse breakdown voltage when the solar cell 1 is shaded, thereby improving the anti-thermal spot performance of the solar cell 1 and realizing the improvement of the thermal spot phenomenon caused by local poor conduction of the solar cell 1.

[0047] It should be noted that the orthographic projection of the recessed portion 111a on the first surface 11a may be circular, polygonal or irregular in shape, etc. It can be specifically determined according to the actual situation, and this embodiment does not limit it here.

[0048] Please refer to Figure 3 、 Figure 4 and Figure 5 Between the first doped layer 111 and the second doped layer 112, there is a spacer region 113. The minimum distance between the doped contact portion 111b and the second doped layer 112 is the width of the spacer region 113. That is to say, although the polarity of the doped contact portion 111b is opposite to that of the first doped layer 111, there is no contact between the doped contact portion 111b and the second doped layer 112, that is, the doped contact portion 111b is not an extended structure extending from the second doped layer 112 to the first doped layer 111.

[0049] Please continue to refer to Figure 4 and Figure 5 Along the thickness direction Z of the solar cell 1, the projection plane of the doped contact portion 111b on the first surface 11a does not coincide with the projection plane of the first electrode 114 on the first surface 11a. That is to say, the doped contact portion 111b does not overlap with the first electrode 114, and there is no contact between the doped contact portion 111b in the first doped layer 111 and the first electrode 114, and no additional metal recombination loss will be introduced.

[0050] Please continue to refer to Figure 5, in some embodiments, the doped contact portion 111b is uniformly distributed in the first doped layer 111. That is to say, the doped contact portions 111b are arranged in an array in the first doped layer 111. By arranging the doped contact portions 111b in an array, a corresponding local conductive path structure can exist at each position of the first doped layer 111 of the solar cell 1, so as to improve the hot spot phenomenon of the solar cell 1.

[0051] In this embodiment, the recessed portion 111a can be formed into an approximately uniform distribution by patterning means such as a mask, an ink process, a laser process, etc., so that local conduction and hot spot reduction can be made more controllable. And, the recessed portion 111a can be completely arranged to avoid the area of the first electrode 114, so as to avoid metal recombination loss.

[0052] Taking the laser process as an example, the formation methods of the first doped layer 111 and the second doped layer 112 can be: first, form the first doped layer 111 on the side of the tunneling oxide layer 116 away from the silicon substrate 11, then remove part of the first doped layer 111 by means of local laser, then form the second doped layer 112 in the area where the first doped layer 111 is removed, and then perform etching and pickling treatments to form a spacer 113 between the first doped layer 111 and the second doped layer 112.

[0053] Based on the formation methods of the first doped layer 111 and the second doped layer 112, the formation method of the recessed portion 111a can be: form the first doped layer 111 on the side of the tunneling oxide layer 116 away from the silicon substrate 11, and after removing part of the first doped layer 111 by means of local laser, the recessed portion 111a can be formed in the first doped layer 111 by means of laser.

[0054] Or, the formation method of the recessed portion 111a can be: form the first doped layer 111 on the side of the tunneling oxide layer 116 away from the silicon substrate 11, and while removing part of the first doped layer 111 by means of local laser, form the recessed portion 111a inside the first doped layer 111. Specifically, it can be set according to the design situation, and this embodiment does not limit it here.

[0055] It can be understood that the methods for forming the recessed portion by using the ink process and the mask process can refer to the above, and this embodiment will not elaborate here.

[0056] Based on the formation methods of the first doped layer 111 and the second doped layer 112, the formation method of the doped contact portion 111b can be: while forming the second doped layer 112 in the area where the first doped layer 111 is removed, form the doped contact portion 111b in the recessed portion 111a. That is to say, the doped contact portion 111b has the same material as the second doped layer 112, so that the doped contact portion 111b has the opposite polarity to the first doped layer 111.

[0057] Please continue to refer to Figure 4 , it can be understood that in some embodiments, the doped contact portion 111b can also be non-uniformly distributed in the first doped layer 111.

[0058] It can be understood that some of the recessed portions 111a can also be randomly formed during the manufacturing process of the solar cell 1. For example, the recessed portions 111a may come from high-temperature processes and subsequent wet processes, etc., which may all form the recessed portions 111a in the first doped layer 111.

[0059] It should be noted that even if some of the recessed portions 111a can be randomly formed during the manufacturing process of the solar cell 1, after the doped contact portion 111b is formed in these recessed portions 111a, the local conduction path formed by the doped contact portion 111b and the first doped layer 111 cannot meet the requirement of reducing hot spots. Therefore, in this embodiment, the recessed portions 111a are further provided in the first doped layer 111, and the doped contact portion 111b is formed in the recessed portions 111a to further reduce the hot spot phenomenon.

[0060] In some embodiments, the area ratio of the recessed portion 111a to the first doped layer 111 is a, where 0.05% ≤ a ≤ 5%. That is to say, the ratio of the area of the orthographic projection of the recessed portion 111a on the first doped layer 111 to the area of the first doped layer 111 is 0.05% - 5%.

[0061] Exemplarily, the ratio of the area of the orthographic projection of the recessed portion 111a on the first doped layer 111 to the area of the first doped layer 111 can be 0.05%, 0.1%, 0.25%, 0.5%, 0.75%, 1%, 1.25%, 1.5%, 1.75%, 2%, 2.25%, 2.5%, 2.75%, 3%, 3.25%, 3.5%, 3.75%, 4%, 4.25%, 4.5%, 4.75%, 5%, etc. Specifically, it can be set according to the actual situation, and this embodiment does not limit it here.

[0062] In this embodiment, the larger the ratio of the area of the orthographic projection of the recessed portion 111a on the first doped layer 111 to the area of the first doped layer 111, the more contact surfaces there are between the doped contact portion 111b in the recessed portion 111a and the first doped layer 111, and the better the local conduction effect. The smaller the ratio of the area of the orthographic projection of the recessed portion 111a on the first doped layer 111 to the area of the first doped layer 111, the fewer contact surfaces there are between the doped contact portion 111b in the recessed portion 111a and the first doped layer 111, and the lower the ability of the doped contact portion 111b to affect the efficiency of the solar cell 1. Therefore, by setting the area ratio of the recessed portion 111a to the first doped layer 111 to be 0.05% - 5%, the local conduction effect of the solar cell 1 can be improved while avoiding affecting the photoelectric conversion efficiency of the solar cell 1.

[0063] Further, the ratio of the area of the orthographic projection of the recess 111a on the first doping layer 111 to the area of the first doping layer 111 is 0.3%-1.5%.

[0064] Exemplarily, the ratio of the area of the orthographic projection of the recess 111a on the first doping layer 111 to the area of the first doping layer 111 can be 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, etc., or the ratio can be enlarged or reduced according to the actual situation, and can be specifically set according to the actual situation. This embodiment does not make a limitation here.

[0065] In some embodiments, the one-dimensional dimension of the recess 111a is b, and 0.5μm ≤ b ≤ 240μm.

[0066] Exemplarily, the one-dimensional dimension of the recess 111a can be 0.5μm, 20μm, 40μm, 60μm, 80μm, 100μm, 120μm, 140μm, 160μm, 180μm, 200μm, 220μm, 240μm, etc., and can be specifically set according to the actual situation. This embodiment does not make a limitation here.

[0067] In this embodiment, the larger the one-dimensional dimension of the recess 111a, the more contact surfaces there are between the doping contact portion 111b in the recess 111a and the first doping layer 111, and the better the local conduction effect brought. The smaller the one-dimensional dimension of the recess 111a, the fewer contact surfaces there are between the doping contact portion 111b in the recess 111a and the first doping layer 111, and the lower the ability of the doping contact portion 111b to affect the efficiency of the solar cell 1. Therefore, by setting the one-dimensional dimension of the recess 111a to be 0.5μm - 240μm, while improving the local conduction efficiency of the solar cell 1, the photoelectric conversion efficiency of the solar cell 1 can be avoided from being affected.

[0068] Wherein, the shape of the projection of the recess 111a on the first doping layer 111 can be circular, rectangular, elliptical, triangular, etc. The one-dimensional dimension of the recess 111a can be the diameter of a circle, the side length of a rectangle or a triangle, the side length of an ellipse, etc., and the one-dimensional dimension of the recess 111a can also be the connection line between two angles, etc.

[0069] Figure 6 It is a schematic diagram in one embodiment when a doping contact portion 111b is formed in the recess 111a in the first doping layer 111. Figure 7 It is a schematic diagram in another embodiment when a doping contact portion 111b is formed in the recess 111a in the first doping layer 111. Figure 8Schematic diagram of another embodiment when a doped contact portion 111b is formed in the recessed portion 111a of the first doped layer 111 Figure 9 Schematic diagram of another embodiment when a doped contact portion 111b is formed in the recessed portion 111a of the first doped layer 111. Please refer to Figure 6 , Figure 7 , Figure 8 and Figure 9 . Along the thickness direction Z perpendicular to the solar cell 1, the doped contact portion 111b covers at least a partial area of the side wall of the recessed portion 111a.

[0070] Among them, the doped contact portion 111b may completely cover all side wall surfaces and the bottom wall surface of the recessed portion 111a. Or, the doped contact portion 111b may cover only a partial side wall surface and not cover the bottom wall surface. Or, the doped contact portion 111b may cover only a partial side wall surface and cover the entire bottom wall surface. Or, the doped contact portion 111b may cover only a partial side wall surface and a partial bottom wall surface. Or, the doped contact portion 111b may cover all side wall surfaces but not cover the bottom wall surface. It can be specifically set according to the actual situation, and this embodiment does not limit it here.

[0071] It can be understood that when the recessed portion 111a is formed in the first doped layer 111, the formed recessed portion 111a may not penetrate through the first doped layer 111, or may completely penetrate through the first doped layer 111. It can be specifically set according to the actual situation, and this embodiment does not limit it here.

[0072] For details, please continue to refer to Figure 6 . The recessed portion 111a does not penetrate through the first doped layer 111, and the doped contact portion 111b covers the bottom wall of the recessed portion 111a. That is to say, the recessed portion 111a does not completely penetrate through the first doped layer 111 in the thickness direction Z of the first doped layer 111, and the doped contact portion 111b covers at least a partial area of the side wall surface of the recessed portion 111a and at least a partial area of the bottom wall surface of the recessed portion 111a.

[0073] In this embodiment, the recessed portion 111a is a groove structure that does not completely penetrate through the first doped layer 111, and the doped contact portion 111b can form a local conduction path with the first doped layer 111 on the side wall surface and the bottom wall surface of the recessed portion 111a.

[0074] Or, please continue to refer to Figure 7, the recess 111a penetrates through the first doped layer 111, a part of the back passivation layer 117 is exposed from the recess 111a, and the doped contact portion 111b covers the back passivation layer 117 exposed from the recess 111a. That is to say, the recess 111a completely penetrates the first doped layer 111 in the thickness direction Z of the first doped layer 111, and the doped contact portion 111b covers at least a part of the side wall surface of the recess 111a and a part of the area of the back passivation layer 117.

[0075] In this embodiment, the recess 111a is a hole structure that completely penetrates the first doped layer 111, and the doped contact portion 111b can form a local conductive path with the first doped layer 111 on the side wall surface of the recess 111a.

[0076] Or, please continue to refer to Figure 8 , the recess 111a penetrates through the first doped layer 111 and the back passivation layer 117, a part of the silicon substrate 11 is exposed from the recess 111a, and the doped contact portion 111b covers the silicon substrate 11 exposed from the recess 111a. That is to say, the recess 111a completely penetrates the first doped layer 111 and the back passivation layer 117 in the thickness direction Z of the first doped layer 111, and the doped contact portion 111b covers at least a part of the side wall surface of the recess 111a and a part of the area of the silicon substrate 11.

[0077] In this embodiment, the recess 111a is a hole structure that completely penetrates the first doped layer 111, and the doped contact portion 111b can form a local conductive path with the first doped layer 111 on the side wall surface of the recess 111a.

[0078] Or, please continue to refer to Figure 9 , the recess 111a penetrates through the first doped layer 111, the back passivation layer 117 and a part of the silicon substrate 11, a part of the silicon substrate 11 is exposed from the recess 111a, and the doped contact portion 111b covers the silicon substrate 11 exposed from the recess 111a. That is to say, the recess 111a penetrates through the first doped layer 111, the back passivation layer 117 and a part of the silicon substrate 11 in the thickness direction Z of the first doped layer 111, and the doped recess 111a covers at least a part of the side wall surface of the recess 111a and a part of the area of the silicon substrate 11.

[0079] In this embodiment, the recess 111a is a hole structure that completely penetrates the first doped layer 111, and the doped contact portion 111b can form a local conductive path with the first doped layer 111 on the side wall surface of the recess 111a.

[0080] Figure 10Schematic diagram in another embodiment when a doped contact portion 111b is formed in the recessed portion 111a of the first doped layer 111. A silicon oxide layer is formed on the surface of the first doped layer 111. When the second doped layer 112 is formed in the region where the first doped layer 111 is removed and the doped contact portion 111b is formed in the recessed portion 111a, it can be provided over the entire surface of the first surface 11a. That is to say, the second doped layer 112 can be formed on the first doped layer 111, and the silicon oxide layer on the surface of the first doped layer 111 can isolate the first doped layer 111 and the second doped layer 112, avoiding direct contact between the first doped layer 111 and the second doped layer 112 and simplifying the manufacturing process.

[0081] This embodiment also provides a tandem cell. The tandem cell includes a top cell, an intermediate connection layer, and a bottom cell. The intermediate connection layer is connected between the bottom cell and the top cell. The top cell is one of a perovskite cell, a cadmium telluride solar cell 1, a copper indium gallium selenide solar cell 1, or a gallium arsenide solar cell 1, and the bottom cell is the above-mentioned solar cell 1.

[0082] For the selection of the intermediate connection layer, it is usually selected from transparent materials with a high refractive index. An effective intermediate connection layer needs to have high light transmittance to reduce the reflection and absorption of light at the connection layer interface, and good electrical conductivity to reduce the impact of series resistance on the device performance. Exemplarily, a transparent conductive metal oxide thin film (ITO) can be used as the intermediate connection layer.

[0083] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A solar cell, characterized in that, The solar cell (1) includes a silicon substrate (11) having a first surface (11a) and a second surface (11b) disposed opposite to each other, and a plurality of first doping layers (111) and a plurality of second doping layers (112) are disposed at intervals on the first surface (11a); A recess (111a) is provided in the first doping layer (111), and a doping contact portion (111b) having a polarity opposite to that of the first doping layer (111) is formed in the recess (111a), and the first doping layer (111) is in contact with the doping contact portion (111b).

2. The solar cell according to claim 1, wherein, There is a spacer region (113) between the first doping layer (111) and the second doping layer (112); The minimum distance between the doping contact portion (111b) and the second doping layer (112) is the width of the spacer region (113).

3. The solar cell according to claim 1, wherein The area ratio of the recess (111a) to the first doping layer (111) is a, where 0.05% ≤ a ≤ 5%.

4. The solar cell according to claim 1, characterized in that, The one-dimensional dimension of the recess (111a) is b, where 0.5 μm ≤ b ≤ 240 μm.

5. The solar cell according to claim 1, wherein The solar cell (1) further includes a first electrode (114) laminated on the first doping layer (111); Along the thickness direction (Z) of the solar cell (1), the projection surface of the doping contact portion (111b) on the first surface (11a) does not coincide with the projection surface of the first electrode (114) on the first surface (11a).

6. The solar cell according to claim 1, characterized in that, The doping contact portions (111b) are uniformly distributed in the first doping layer (111).

7. The solar cell according to any one of claims 1 to 6, characterized in that, Along a direction perpendicular to the thickness direction (Z) of the solar cell (1), the doping contact portion (111b) covers at least a partial region of the side wall of the recess (111a).

8. The solar cell according to claim 7, characterized in that, The recess (111a) does not penetrate the first doping layer (111), and the doping contact portion (111b) covers the bottom wall of the recess (111a).

9. The solar cell according to claim 7, wherein The recess (111a) penetrates the first doping layer (111), and a part of the silicon substrate (11) is exposed from the recess (111a); The doping contact portion (111b) covers the silicon substrate (11) exposed from the recess (111a).

10. A photovoltaic module, characterized in that, The photovoltaic module (10) includes a first cover plate (101), a first encapsulant film (102), a battery string (103), a second encapsulant film (104), and a second cover plate (105) which are laminated; The battery string (103) includes a plurality of electrically connected solar cells (1), and the solar cell (1) is the solar cell (1) according to any one of claims 1 to 9.

11. A stacked battery, characterized in that, The stacked cell includes a top cell, an intermediate connection layer, and a bottom cell, and the intermediate connection layer is connected between the top cell and the bottom cell; The top cell is one of a perovskite cell, a cadmium telluride solar cell, a copper indium gallium selenide solar cell, or a gallium arsenide solar cell, and the bottom cell is the solar cell (1) according to any one of claims 1 to 9.

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