Solar cell and manufacturing method therefor, and electric apparatus and power generation apparatus

Abstract

Disclosed in the present application are a solar cell and a manufacturing method therefor, and a photovoltaic module, an electric apparatus and a power generation apparatus. The solar cell comprises: a substrate and at least one sub-cell located on the substrate, wherein the sub-cell comprises at least a first electrode layer, a light-absorbing layer, and a second electrode layer, and the orthographic projections of the first electrode layer, the light-absorbing layer, and the second electrode layer of each sub-cell on a plane of the substrate have an overlapping region; the sub-cell further comprises a first transport layer located between the first electrode layer and the light-absorbing layer, the light-absorbing layer comprises a first sub-portion and a second sub-portion which are connected to each other, the lower surface of the first sub-portion is lower than the upper surface of the first transport layer, and the orthographic projection of the first sub-portion on the plane of the substrate falls within the overlapping region; and / or, the sub-cell further comprises a second transport layer located between the light-absorbing layer and the second electrode layer, the second electrode layer comprises a third sub-portion and a fourth sub-portion which are connected to each other, the lower surface of the third sub-portion is lower than the upper surface of the second transport layer, and the orthographic projection of the third sub-portion on the plane of the substrate falls within the overlapping region.

Description

A solar cell, its manufacturing method, an electrical device, and a power generation device. Technical Field

[0001] This disclosure relates to the field of solar cell technology, and in particular to a solar cell, a method for manufacturing the same, an electrical device, and a power generation device. Background Technology

[0002] In recent years, thin-film solar cells have attracted widespread attention from industry investors due to their high efficiency, simple process, and low cost. Thin-film solar cells typically include a first electrode layer, a second electrode layer, and a functional layer located between the first and second electrode layers. The functional layer includes at least a light-absorbing layer, which can generate electron-hole pairs when excited by incident photons. The flow of electrons and holes generates current, thereby realizing the conversion from light energy to electrical energy. Summary of the Invention

[0003] This application provides a solar cell to improve the light incident rate within the light-absorbing layer.

[0004] This application is achieved through the following technical solution.

[0005] The first aspect of this application provides a solar cell, comprising:

[0006] A substrate, and at least one sub-cell located on the substrate, the sub-cell comprising at least a first electrode layer, a light-absorbing layer, and a second electrode layer stacked sequentially from bottom to top on the substrate, wherein the orthographic projections of the first electrode layer, the light-absorbing layer, and the second electrode layer of each sub-cell onto the plane of the substrate have an overlapping area; wherein...

[0007] The sub-cell also includes a first transport layer located between the first electrode layer and the light-absorbing layer. The light-absorbing layer includes a first sub-section and a second sub-section connected together. The lower surface of the first sub-section is lower than the upper surface of the first transport layer. The second sub-section covers the first transport layer and the first sub-section. The orthographic projection of the first sub-section onto the substrate plane falls into the overlapping area; and / or,

[0008] The sub-cell also includes a second transport layer located between the light-absorbing layer and the second electrode layer. The second electrode layer includes a third sub-section and a fourth sub-section connected together. The lower surface of the third sub-section is lower than the upper surface of the second transport layer. The fourth sub-section covers the second transport layer and the third sub-section. The orthographic projection of the third sub-section on the substrate plane falls into the overlapping area.

[0009] The sub-cell includes a first transport layer located between a first electrode layer and a light-absorbing layer. At least a portion of the incident light enters from the side where the first transport layer is located and reaches the light-absorbing layer. The lower surface of the first sub-part of the light-absorbing layer is lower than the upper surface of the first transport layer. Alternatively, the sub-cell includes a second transport layer disposed between the light-absorbing layer and a second electrode layer. At least a portion of the incident light enters from the side where the second transport layer is located and reaches the light-absorbing layer. The lower surface of the third sub-part of the second electrode layer is lower than the upper surface of the second transport layer. Thus, the presence of the first and / or third sub-parts partially thins the first and / or second transport layers, reducing their bulk resistance and consequently the overall resistance of the solar cell. Furthermore, it reduces parasitic absorption of incident light by the first and / or second transport layers, increasing their transmittance and thus increasing the light absorption rate of the light-absorbing layer. Additionally, the presence of the first and / or third sub-parts can block some of the lateral transport of charge carriers within the first and / or second transport layers, thereby reducing non-recombination losses of charge carriers.

[0010] In any embodiment, in the direction perpendicular to the substrate plane, the ratio of the thickness of the first sub-part to the thickness of the first transport layer ranges from 0.2 to 1, and / or the ratio of the thickness of the third sub-part to the thickness of the second transport layer ranges from 0.2 to 1. This increases applicability to various scenarios, and when within the aforementioned ranges, by controlling the thickness of the first sub-part and / or the third sub-part, the transmittance of the first transport layer and / or the second transport layer can be increased while effectively controlling the lateral transport of charge carriers within the first transport layer and / or the second transport layer, as well as the bulk resistance of the first transport layer and / or the second transport layer.

[0011] In any embodiment, the lower surface of the first sub-part is higher than the lower surface of the first transport layer, and / or the lower surface of the third sub-part is higher than the lower surface of the second transport layer. Thus, in practical applications, when the first transport layer and / or the second transport layer are processed using scribing or etching processes to form a recessed structure, and the first sub-part and / or the third sub-part are formed within this recessed structure, the scribing or etching processes are prevented from penetrating the first transport layer and / or the second transport layer, thereby avoiding damage to other film layers located below the first transport layer and / or the second transport layer and affecting the performance of the solar cell.

[0012] In any embodiment, the cross-sectional shape of the first sub-part along a direction parallel to the plane of the substrate includes one or a combination of circles, ellipses, polygons, and irregular shapes, and / or, the cross-sectional shape of the third sub-part includes one or a combination of circles, ellipses, polygons, and irregular shapes. This increases the applicability to various scenarios.

[0013] In any embodiment, the light-absorbing layer of each sub-cell includes a plurality of first sub-parts extending along a first direction and arranged along a second direction intersecting the first direction. Both the first and second directions are parallel to the substrate plane. Thus, the arrangement of the plurality of first sub-parts can further increase the transmittance of the first transport layer and further reduce the transport of charge carriers along the second direction within the first transport layer, as well as the bulk resistance of the first transport layer; and / or,

[0014] Each sub-cell's second electrode layer includes multiple third sub-sections. These multiple third sub-sections extend along a third direction and are arranged along a fourth direction intersecting the third direction. Both the third and fourth directions are parallel to the substrate plane. Thus, the arrangement of multiple third sub-sections can further increase the light transmittance of the second transport layer and further reduce the transport of charge carriers along the fourth direction within the second transport layer, as well as the bulk resistance of the second transport layer.

[0015] In any embodiment, in the first direction, the two end sidewalls of the first sub-section are flush with the two end sidewalls of the first transport layer. Thus, by cutting off the first transport layer along the first direction, the transport of charge carriers within the first transport layer of each sub-cell along the second direction can be further reduced, thereby further reducing carrier non-recombination losses. And / or,

[0016] In the third direction, the two end sidewalls of the third sub-section are flush with the two end sidewalls of the second transport layer. In this way, the third sub-section cuts off the second transport layer along the first direction, which can further reduce the transport of charge carriers in the second transport layer of each sub-cell along the second direction, thereby further reducing the non-recombination loss of charge carriers.

[0017] In any embodiment, the solar cell further includes a passivation layer, which is located at least between the first transport layer and the light-absorbing layer. The passivation layer can reduce interface defects between the light-absorbing layer and the first transport layer, reduce the probability of carriers being trapped during transport, and thereby improve the carrier transport efficiency.

[0018] In any embodiment, the light-absorbing layer is a perovskite light-absorbing layer. This configuration increases the light absorption rate of the perovskite light-absorbing layer.

[0019] In any embodiment, the first transport layer is an electron transport layer or a hole transport layer, and / or the second transport layer is an electron transport layer or a hole transport layer, to increase the applicable scenarios.

[0020] A second aspect of this application provides a method for manufacturing a solar cell, comprising:

[0021] Provide substrate;

[0022] Forming at least one sub-cell on a substrate includes: sequentially forming a first electrode layer, a light-absorbing layer, and a second electrode layer on the substrate from bottom to top, wherein the orthographic projections of the first electrode layer, the light-absorbing layer, and the second electrode layer of each sub-cell onto the substrate plane have an overlapping area; wherein...

[0023] The formation of the sub-cell further includes: forming a first transport layer between the first electrode layer and the light-absorbing layer, wherein at least one first recessed structure is formed within the first transport layer, and the orthographic projection of the first recessed structure onto the substrate plane is located in the overlapping region; the light-absorbing layer fills the first recessed structure and covers the first transport layer and the first recessed structure; and / or,

[0024] The formation of the sub-cell further includes: forming a second transport layer between the light-absorbing layer and the second electrode layer, wherein at least one second recessed structure is formed in the second transport layer, and the orthogonal projection of the second recessed structure onto the substrate plane is located in the overlapping area; the second electrode layer fills the second recessed structure and covers the second transport layer and the second recessed structure.

[0025] In this application, a first transmission layer is disposed between a first electrode layer and a light-absorbing layer, and a first recessed structure is formed within the first transmission layer, with a portion of the light-absorbing layer filling the first recessed structure. Alternatively, a second transmission layer is disposed between the light-absorbing layer and a second electrode layer, and a second recessed structure is formed within the second transmission layer, with a portion of the second electrode layer filling the second recessed structure. Thus, when at least a portion of the incident light enters from the side where the first transmission layer is located and reaches the light-absorbing layer, and / or at least a portion of the incident light enters from the side where the second transmission layer is located and reaches the light-absorbing layer, the first recessed structure and / or the second recessed structure affect the first transmission layer and / or the light-absorbing layer. The second transport layer partially thins the solar cell, reducing the bulk resistance of the first and / or second transport layers, thereby reducing the overall resistance of the solar cell. It also reduces parasitic absorption of incident light by the first and / or second transport layers, increasing their transmittance and consequently increasing the light absorption rate of the light-absorbing layer. Furthermore, the portion of the light-absorbing layer located within the first recessed structure and / or the second electrode layer located within the second recessed structure can block some of the lateral transport of charge carriers within the first and / or second transport layers, thereby reducing non-recombination losses of charge carriers.

[0026] In any embodiment, a second transport layer is formed between the light-absorbing layer and the second electrode layer, comprising:

[0027] After forming the first electrode layer and before forming the light-absorbing layer, a first transport layer with a first recessed structure is formed on the first electrode layer using a mask process; or, a first transport material layer is formed on the first electrode layer, and a laser scribing or photolithography process is performed on the first transport material layer to form the first transport layer and at least one first recessed structure located within the first transport layer; and / or,

[0028] A second transport layer is formed between the light-absorbing layer and the second electrode layer, comprising:

[0029] After the light-absorbing layer is formed and before the second electrode layer is formed, a second transport layer with a second recessed structure inside is formed on the light-absorbing layer using a mask process; or, a second transport material layer is formed on the light-absorbing layer, and a laser scribing process or a photolithography process is performed on the second transport material layer to form the second transport layer and at least one second recessed structure located in the second transport layer.

[0030] In this way, the first transport layer and / or the second transport layer can be formed through different methods, increasing the number of applicable scenarios.

[0031] In any embodiment, during the step of performing laser scribing to form the first recessed structure and / or the second recessed structure, the laser power ranges from 0.2W to 0.8W; and / or the laser pulse frequency ranges from 200kHz to 500kHz; and / or the laser wavelength ranges from 450nm to 600nm. Thus, by controlling the laser power, pulse frequency, and wavelength to be within the aforementioned ranges, it is possible to control the formation of the first recessed structure and / or the second recessed structure to obtain a first recessed structure and / or the second recessed structure with a predetermined depth, without damaging the first electrode layer located below the first transport layer.

[0032] In any embodiment, after forming the first transport layer and the first recessed structure within the first transport layer, and before forming the light-absorbing layer, the method further includes: forming a passivation layer, the passivation layer at least covering the upper surface of the first transport layer and the surface exposed by the first recessed structure. Thus, after the subsequent formation of the light-absorbing layer, the passivation layer is located between the light-absorbing layer and the first transport layer. The passivation layer can reduce interface defects between the light-absorbing layer and the first transport layer, reducing the probability of carriers being trapped during transport, thereby improving carrier transport efficiency.

[0033] A third aspect of this application also provides a photovoltaic module, which includes the solar cell of the first aspect of this application.

[0034] The fourth aspect of this application also provides an electrical device, which includes the photovoltaic module of the third aspect of this application.

[0035] The fifth aspect of this application also provides a power generation device, which includes the photovoltaic module of the third aspect of this application.

[0036] Details of one or more embodiments of this disclosure are set forth in the following drawings and description. Other features and advantages of this disclosure will become apparent from the specification and the drawings. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1a is a structural block diagram of a photovoltaic module provided in some embodiments of this application; Figure 1b is a structural block diagram of an electrical device provided in some embodiments of this application; Figure 1c is a structural block diagram of a power generation device provided in some embodiments of this application;

[0039] Figures 2a to 2f are different examples of structural schematic diagrams of solar cells provided in some embodiments of this application;

[0040] Figure 3a shows different examples of the cross-sectional shapes of the first sub-part and the second sub-part along the direction parallel to the plane of the substrate provided in some embodiments of this application; Figures 3b and 3c are respectively top views of the first sub-part and the third sub-part provided in some embodiments of this application;

[0041] Figure 4 is a flowchart of a method for manufacturing a solar cell according to some embodiments of this application;

[0042] Figures 5 to 10 are schematic flowcharts of methods for manufacturing solar cells according to some embodiments of this application;

[0043] Figures 11 and 12 are schematic flowcharts of methods for manufacturing solar cells according to other embodiments of this application;

[0044] Figure 13 is a schematic flowchart of a method for manufacturing a solar cell according to some embodiments of this application;

[0045] Figure 14a shows different examples of the cross-sectional shapes of the first recessed structure and the second recessed structure provided in some embodiments of this application along the direction parallel to the plane of the substrate; Figures 14b and 14c are respectively top views of the first recessed structure and the second recessed structure provided in some embodiments of this application.

[0046] Figures (1) to (3) in Figure 15 are top views of the first transmission layer formed after different lasers are used to perform scribing processes on the first transmission layer.

[0047] Figure 16a shows the fluorescence spectrum of the perovskite absorbing layer provided in Example 1 and Comparative Example 1; Figure 16b shows the light absorption intensity of the perovskite absorbing layer provided in Example 1 and Comparative Example 1.

[0048] Explanation of reference numerals in the attached figures: 1 Solar cell; 100 Photovoltaic module; 2 Electrical device; 3 Power generation device; 10 Substrate; 101 Overlapping area; 102 Dead area; 11 First electrode layer; 121 First transport layer; 122 Second transport layer; 13 Light-absorbing layer; 131 First sub-section; 132 Second sub-section; 14 Second electrode layer; 141 Third sub-section; 142 Fourth sub-section; T1 First trench; T2 Second trench; T3 Third trench; S1 First recessed structure; S2 Second recessed structure; 15 Sub-cell; 16 Passivation layer. Detailed Implementation

[0049] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0050] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of this disclosure. However, it will be apparent to those skilled in the art that this disclosure may be practiced without one or more of these details. In other instances, to avoid confusion with this disclosure, certain technical features well-known in the art have not been described; that is, not all features of actual embodiments are described herein, nor are well-known functions and structures described in detail.

[0051] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this disclosure, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion. And the discussion of a second element, component, area, layer, or portion does not imply that the first element, component, area, layer, or portion necessarily exists in this disclosure.

[0052] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below,” “under,” or “below” other elements or features will be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0053] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprise” and / or “comprising,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0054] In recent years, thin-film solar cells have attracted widespread attention from industry investors due to their high efficiency, simple manufacturing process, and low cost. A thin-film solar cell typically includes a first electrode layer, a second electrode layer, and a functional layer located between the first and second electrode layers. The functional layer includes at least a light-absorbing layer, which generates electron-hole pairs upon excitation by incident photons. The flow of electrons and holes generates current, thereby converting light energy into electrical energy. However, light loss due to reflection or absorption at the interfaces between different film layers within the functional layer leads to a decrease in the light absorption rate of the light-absorbing layer. Some embodiments incorporate an anti-reflection or anti-reflection coating on the light-incident side to increase light transmittance; however, these coatings are costly to manufacture, easily worn, and unsuitable for large-area industrial production.

[0055] Based on this, the inventors propose a technical solution in which the sub-cell includes a first transmission layer located between a first electrode layer and a light-absorbing layer. At least a portion of the incident light enters from the side where the first transmission layer is located and reaches the light-absorbing layer, and the lower surface of the first sub-part of the light-absorbing layer is lower than the upper surface of the first transmission layer. And / or the sub-cell includes a second transmission layer disposed between the light-absorbing layer and a second electrode layer. At least a portion of the incident light enters from the side where the second transmission layer is located and reaches the light-absorbing layer, and the lower surface of the third sub-part of the second electrode layer is lower than the upper surface of the second transmission layer. Thus, the first sub-part and / or the second electrode layer... The presence of the third sub-sub ...

[0056] The technical solutions described in the embodiments of this application are applicable to photovoltaic modules that include solar cells, electrical devices that use photovoltaic modules, and power generation devices that use photovoltaic modules.

[0057] Figure 1a is a schematic block diagram of a photovoltaic module 100 provided in some embodiments of this application. As shown in Figure 1a, the photovoltaic module 100 includes a solar cell 1. There may be one or more solar cells 1. If there are multiple solar cells 1, they may be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that some of the multiple solar cells 1 are connected in series and others in parallel, which can provide higher voltage and current.

[0058] Figure 1b is a schematic block diagram of an electrical device 2 provided in some embodiments of this application. The electrical device 2 can be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, and power tool, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-described electrical device 2.

[0059] Figure 1c is a schematic block diagram of a power generation device 3 provided in some embodiments of this application. The power generation device 3 includes a photovoltaic module 100. The power generation device 3 may also have a control system and a transmission system. The power generation device 3 provided in this application uses the control system and transmission system to adjust the electrical energy generated by the photovoltaic module 100 into electrical energy that can match the electrical equipment.

[0060] Hereinafter, some embodiments of the present application will be described in detail with reference to Figures 2a to 2d and Figures 3a to 3c.

[0061] As shown in the figure, this application provides a solar cell, including: a substrate 10, and at least one sub-cell 15 located on the substrate 10. The sub-cell 15 includes at least a first electrode layer 11, a light-absorbing layer 13, and a second electrode layer 14 stacked sequentially from bottom to top on the substrate 10. The orthographic projections of the first electrode layer 11, the light-absorbing layer 13, and the second electrode layer 14 of each sub-cell 15 onto the plane of the substrate 10 have an overlapping region 101. The sub-cell 15 further includes a first transport layer 121 located between the first electrode layer 11 and the light-absorbing layer 13. The light-absorbing layer 13 includes a first sub-part 131 and a second sub-part 132 connected together. The lower surface of the first sub-part 131 is lower than the upper surface of the first transport layer 121, and the second sub-part 132 covers the first transport layer 121 and the second sub-part 132. The orthographic projection of the first sub-part 131 onto the plane of the substrate 10 falls into the overlapping region 101; and / or...

[0062] The sub-cell 15 also includes a second transport layer 122 located between the light-absorbing layer 13 and the second electrode layer 14. The second electrode layer 14 includes a third sub-part 141 and a fourth sub-part 142 connected together. The lower surface of the third sub-part 141 is lower than the upper surface of the second transport layer 122. The fourth sub-part 142 covers the second transport layer 122 and the third sub-part 141. The orthographic projection of the third sub-part 141 on the plane of the substrate 10 falls into the overlapping area 101.

[0063] It should be noted that "up" here and in the following text refers to the upward direction or upper side in the attached drawings, and "down" refers to the downward direction or lower side in the attached drawings. Here, "from bottom to top" can be understood as a direction pointing from the lower side of the substrate 10 to the upper side and perpendicular to the plane of the substrate 10.

[0064] The term "lower than" in this context and in the following text means that, in the direction perpendicular to the substrate 10, the distance between one part and the substrate 10 is less than the distance between the other part and the substrate 10. For example, "the lower surface of the first sub-part 131 is lower than the upper surface of the first transmission layer 121" means that the distance between the lower surface of the first sub-part 131 and the substrate 10 is less than the distance between the upper surface of the first transmission layer 121 and the substrate 10. Similarly, "the lower surface of the third sub-part 141 is lower than the upper surface of the second transmission layer 122" means that the distance between the lower surface of the third sub-part 141 and the substrate 10 is less than the distance between the upper surface of the second transmission layer 122 and the substrate 10.

[0065] It should be understood that the descriptions of "above", "below", "higher than", and "lower than" in this application are not to be construed as limiting the location of the solar cell.

[0066] In some embodiments, the substrate 10 may be made of a transparent material, such as one or more of glass, tempered glass, quartz, and organic flexible materials. The organic flexible material may include one or more of transparent polymer materials, such as polyimide, polyethylene terephthalate, and polyethersulfone resin.

[0067] In some embodiments, the material of the first electrode layer 11 may be a transparent conductive material, including but not limited to one or more of indium tin oxide (ITO), aluminum zinc oxide (AZO), indium tungsten oxide (IWO), indium cerium oxide (ICO), fluorine-doped tin oxide (FTO), zinc-doped zinc oxide (IZO), and antimony-doped tin oxide (ATO), such as fluorine-doped tin oxide (FTO).

[0068] In some embodiments, the material of the second electrode layer 14 may include a metal electrode material, a carbon material, or a composite electrode material composed of a metal electrode material and a transparent electrode material; wherein, the metal electrode material includes one or more of silver, aluminum, gold, copper, titanium, chromium, nickel, platinum, and palladium, and the carbon material includes graphene, etc.

[0069] In some embodiments, the light-absorbing layer 13 may include one or more of the following: a perovskite light-absorbing layer, an amorphous silicon light-absorbing layer, a copper indium gallium selenide light-absorbing layer, a cadmium telluride light-absorbing layer, a gallium arsenide light-absorbing layer, and an organic dye light-absorbing layer. The light-absorbing layer can be used to prepare thin-film solar cells with a thickness on the order of micrometers or nanometers, thereby expanding the application scenarios of solar cells.

[0070] Furthermore, the light-absorbing layer 13 may include a perovskite light-absorbing layer. This configuration increases the light absorption rate of the perovskite light-absorbing layer, thereby increasing the power generation of the perovskite solar cell. In some embodiments, the molecular formula of the perovskite light-absorbing layer material satisfies ABX3 or A2CDX6. Specifically, the material of the perovskite light-absorbing layer can be an inorganic perovskite material, an organic perovskite material, or an organic-inorganic hybrid perovskite material. For example, the material of the perovskite light-absorbing layer can be CsPbI2Br or MAPbBr3 (where MA represents the methylamine cation (CH3NH3)). + )) or FAPbI3 (where FA represents formamidinium cation (CH(NH2)2) + )).

[0071] In some embodiments, the first transport layer 121 is an electron transport layer or a hole transport layer. As shown in Figures 2a to 2d, in some embodiments, the solar cell further includes a second transport layer 122, which is located between the light-absorbing layer 13 and the second electrode layer 14. The second transport layer 122 can be either an electron transport layer or a hole transport layer, and the first transport layer 121 and the second transport layer 122 are different. For example, the first transport layer 121 is an electron transport layer and the second transport layer 122 is a hole transport layer, or the first transport layer 121 is a hole transport layer and the second transport layer 122 is an electron transport layer. The provision of the electron transport layer and / or the hole transport layer helps to extract and transport the electron-hole pairs generated by the light-absorbing layer 13 to the corresponding electrodes, thereby improving the carrier transport capability. Depending on the actual situation, the first transport layer 121 and the second transport layer 122 can be provided on both sides of the light-absorbing layer 13, or the first transport layer 121 or the second transport layer 122 can be provided only on one side of the light-absorbing layer 13; there is no limitation here.

[0072] The electron transport layer material is an n-type semiconductor with electron transport capabilities. Specific materials include, but are not limited to, titanium oxide (TiO2), tin oxide (SnO2), zinc oxide (ZnO), vanadium oxide (V2O5), zinc tin oxide (Zn2SnO4), and fullerene C. 60 (C 60 ), fullerene C 70 (C 70 ) and fullerene derivatives (such as [6,6]-phenyl-C61-butyrate isomethyl ester, PC 61 One or more of BM, etc., without specific restrictions here.

[0073] The hole transport layer material is a p-type semiconductor with hole transport capability. Specific materials include, but are not limited to, one or more of the following: nickel oxide (NiOx), cuprous oxide (Cu2O), molybdenum oxide (MoO3), copper iodide (CuI), cuprous thiocyanate (CuSCN), zinc oxide, 2,2',7,7'-tetratetra(N,N-p-methoxyaniline)-9, 9'-spirodifluorene (Spiro-OMeTAD), poly[bis(4-phenyl)((2,4,6-trimethylphenyl)amine] (PTAA), and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphate (Me-4PACz), etc., without specific limitations. In some embodiments, the hole transport layer material is nickel oxide (NiOx).

[0074] In some embodiments, the solar cell further includes a barrier layer (not shown) located between the second transport layer 122 and the second electrode layer 14. In some embodiments, the second transport layer 122 is an electron transport layer, and the material of the barrier layer includes one or more of BCP (copper bath alloy) or SnO2, such as BCP (copper bath alloy).

[0075] The number of sub-cells 15 can be one or more. As shown in Figures 2a to 2d, in some embodiments, the number of sub-cells 15 is multiple. Specifically, the solar cell further includes: a first trench T1 extending along a fifth direction and penetrating the first electrode layer 11; a second trench T2 extending along a fifth direction and penetrating the light-absorbing layer 13, the first transmission layer 121, and / or the second transmission layer 122, wherein the second electrode layer 14 also fills the second trench T2; and a third trench T3 extending along a fifth direction and penetrating the second electrode layer 14, the light-absorbing layer 13, the first transmission layer 121, and / or the second transmission layer 122; wherein the first trench T1, the second trench T2, and the third trench T3 are alternately arranged along a sixth direction to divide the first electrode layer 11, the light-absorbing layer 13, the second electrode layer 14, the first transmission layer 121, and / or the second transmission layer 122 into a plurality of sub-cells 15; the plurality of sub-cells 15 are arranged along the sixth direction, and two adjacent sub-cells 15 are connected in series through the second electrode layer 14 located in the second trench T2, and two adjacent sub-cells 15 are separated by the third trench T3.

[0076] In some embodiments, the first transport layer 121 is further filled with a first trench T1.

[0077] Here, the fifth and sixth directions are perpendicular or oblique and are both parallel to the plane of the substrate 10.

[0078] In some implementations, the vertically overlapping area of ​​the first electrode layer 11, the light-absorbing layer 13, and the second electrode layer 14 is the active area of ​​the sub-cell 15, that is, the orthographic projection of the active area of ​​the sub-cell 15 onto the plane of the substrate 10 coincides with the overlapping area 101; between two adjacent sub-cells 15, the area where the first trench T1, the second trench T2, and the third trench T3 are located is the dead area of ​​the sub-cell 15, and the first sub-part 131 and the third sub-part 141 are located within the active area of ​​the sub-cell 15.

[0079] As shown in Figure 2a, in some embodiments, a first transmission layer 121 is disposed between the first electrode layer 11 and the light-absorbing layer 13. The light-absorbing layer 13 includes a first sub-part 131, and the lower surface of the first sub-part 131 is lower than the upper surface of the first transmission layer 121. Thus, the presence of the first sub-part 131 partially thins the first transmission layer 121, reducing the bulk resistance of the first transmission layer 121 and thereby reducing the overall resistance of the solar cell. On the other hand, when incident light enters from the side of the substrate 10 where the first electrode layer 11 and the first transmission layer 121 are disposed and reaches the light-absorbing layer 13, the parasitic absorption of the incident light by the first transmission layer 121 is reduced, increasing the transmittance of the first transmission layer 121, thereby increasing the light absorption rate of the light-absorbing layer 13. Furthermore, the first sub-part 131 is located in the active region of the sub-cell 15, which can effectively increase the light absorption rate of the light-absorbing layer 13 located in the active region, thereby helping to improve the power generation of the solar cell. Furthermore, the presence of the first sub-section 131 can block the lateral transmission of some charge carriers within the first transport layer 121, thereby reducing the non-recombination loss of charge carriers.

[0080] As shown in Figure 2b, in some other embodiments of this application, a second transmission layer 122 is disposed between the light-absorbing layer 13 and the second electrode layer 14. The second electrode layer 14 includes at least one third sub-part 141, and the lower surface of the third sub-part 141 is lower than the upper surface of the second transmission layer 122. Thus, the presence of the third sub-part 141 partially thins the second transmission layer 122, thereby reducing the bulk resistance of the second transmission layer 122 and thus reducing the overall resistance of the solar cell. On the other hand, when incident light enters from the side of the substrate 10 where the second electrode layer 14 and the second transmission layer 122 are disposed and reaches the light-absorbing layer 13, the parasitic absorption of the incident light by the second transmission layer 122 is reduced, and the transmittance of the second transmission layer 122 is increased, thereby increasing the light absorption rate of the light-absorbing layer 13. Furthermore, the third sub-part 141 is located in the active region of the sub-cell 15, which can effectively increase the light absorption rate of the light-absorbing layer 13 located in the active region, thereby helping to increase the power generation of the solar cell. Furthermore, the presence of the third sub-section 141 can block the lateral transmission of some charge carriers within the second transport layer 122, thereby reducing the non-recombination loss of charge carriers.

[0081] As shown in Figure 2a, in an embodiment where the light-absorbing layer 13 includes a first sub-section 131, the sub-cell 15 may further include a second transport layer 122 located between the light-absorbing layer 13 and the second electrode layer 14. The second electrode layer 14 may not have a third sub-section 141, and the lower surface of the second electrode layer 14 located in the active region is higher than the upper surface of the first transport layer 121 located in the active region. However, this is not a limitation; the second transport layer 122 may not be provided between the light-absorbing layer 13 and the second electrode layer 14.

[0082] The term "above" here and below means that, in the direction perpendicular to the substrate 10, one electrode is farther from the substrate 10 than the other. For example, the lower surface of the second electrode layer 14 located in the active region being higher than the upper surface of the first transport layer 121 located in the active region means that the distance between the lower surface of the second electrode layer 14 located in the active region and the substrate 10 is greater than the distance between the upper surface of the first transport layer 121 located in the active region and the substrate 10.

[0083] As shown in Figure 2b, in an embodiment where the second electrode layer 14 includes a third sub-section 141, the sub-cell 15 may further include a first transmission layer 121 located between the first electrode layer 11 and the light-absorbing layer 13, and the light-absorbing layer 13 may not have the first sub-section 131, with the lower surface of the light-absorbing layer 13 being higher than the upper surface of the first transmission layer 121. However, this is not a limitation; the first transmission layer 121 may not be provided between the first electrode layer 11 and the light-absorbing layer 13.

[0084] However, it is not limited to this. As shown in Figure 2c, while the first transmission layer 121 is provided between the first electrode layer 11 and the light-absorbing layer 13, the second transmission layer 122 is provided between the light-absorbing layer 13 and the second electrode layer 14. The light-absorbing layer 13 includes a first sub-part 131, and the second electrode layer 14 includes a third sub-part 141. In this way, when light is simultaneously incident on both sides of the sub-cell 15 where the first electrode layer 11 and the second electrode layer 12 are provided, the presence of the first sub-part 131 and the third sub-part 141 can simultaneously improve the light transmittance of the first transmission layer 121 and the second transmission layer 122, and simultaneously reduce the bulk resistance of the first transmission layer 121 and the second transmission layer 122, as well as block the lateral movement of some charge carriers in the first transmission layer and the second transmission layer 122.

[0085] In some embodiments, the ratio of the thickness of the first sub-part 131 to the thickness of the first transport layer 121 in the direction perpendicular to the plane of the substrate 10 is between 0.2 and 1 (including the endpoint value), such as 0.2, 0.5, 0.7, 0.8, 0.9, 1, etc. This increases the applicability of different scenarios, and when it is within the above range, the transmittance of the first transport layer 121 can be increased by controlling the thickness of the first sub-part 131, while effectively controlling the lateral transport of charge carriers in the first transport layer 121 and the bulk resistance of the first transport layer 121.

[0086] In some embodiments, the ratio of the thickness of the third sub-part 141 to the thickness of the second transport layer 122 in the direction perpendicular to the plane of the substrate 10 is between 0.2 and 1 (including the endpoint value), such as 0.2, 0.5, 0.7, 0.8, 0.9, 1, etc. This increases the applicability of different scenarios, and when it is within the above range, the transmittance of the second transport layer 122 can be increased by controlling the thickness of the third sub-part 141, while effectively controlling the lateral transport of charge carriers in the second transport layer 122 and the bulk resistance of the second transport layer 122.

[0087] As shown in Figures 2a and 2c, in some embodiments, the lower surface of the first sub-part 131 is flush with the lower surface of the first transport layer 121, meaning the first sub-part 131 can penetrate the first transport layer 121. However, this is not the only possibility. As shown in Figure 2d, in other embodiments of this application, the lower surface of the first sub-part 131 may be higher than the lower surface of the first transport layer 121, meaning the first sub-part 131 does not penetrate the first transport layer 121. Thus, in practical applications, when a scribing or etching process is used to form a recessed structure in the first transport layer 121, and a light-absorbing layer 13 is filled in the recessed structure to form the first sub-part 131, the scribing process or the etching process is prevented from penetrating the first transport layer 121, thereby avoiding damage to the first electrode layer 11 located below the first transport layer 121 and affecting the performance of the solar cell.

[0088] In some embodiments, the lower surface of the third sub-part 141 is flush with the lower surface of the second transport layer 122, meaning the third sub-part 141 can penetrate the second transport layer 122. However, this is not the only possibility. As shown in FIG2d, in other embodiments of this application, the lower surface of the third sub-part 141 may also be higher than the lower surface of the second transport layer 122, meaning the third sub-part 141 does not penetrate the second transport layer 122. Thus, in practical applications, when a scribing or etching process is used to form a recessed structure in the second transport layer 122, and the second electrode layer 14 is filled in the recessed structure to form the third sub-part 141, the scribing process is prevented from penetrating the second transport layer 122, thereby avoiding damage to the light-absorbing layer 13 located below the second transport layer 122 and affecting the performance of the solar cell.

[0089] As shown in Figure 3a, in some embodiments, the cross-sectional shape of the first sub-part 131 along the direction parallel to the plane of the substrate 10 and the cross-sectional shape of the third sub-part 141 include one or a combination of circles, ellipses, polygons, irregular shapes, etc., to increase scene adaptability.

[0090] As shown in FIG3b, in some embodiments, the light-absorbing layer 13 of each sub-cell 15 includes a plurality of first sub-parts 131. The plurality of first sub-parts 131 extend along a first direction and are arranged along a second direction intersecting the first direction. Both the first and second directions are parallel to the plane of the substrate 10. In this way, the arrangement of the plurality of first sub-parts 131 can further increase the light transmittance of the first transport layer 121 and further reduce the transport of charge carriers in the first transport layer 121 along the second direction, as well as the bulk resistance of the first transport layer 121.

[0091] Here, the first direction can be the same as the extension direction of the first trench T1, the second trench T2, and the third trench T3 (i.e., the fifth direction), and the second direction can be the same as the arrangement direction of the first trench T1, the second trench T2, and the third trench T3 (i.e., the sixth direction). However, it is not limited to this; the first direction can also intersect with the fifth direction, and the second direction can also intersect with the sixth direction.

[0092] As shown in Figure 3b, in some embodiments, in the first direction, the two end sidewalls of the first sub-section 131 are flush with the two end sidewalls of the first transport layer 121, respectively. That is, the first sub-section 121 cuts off the first transport layer 121 along the first direction. In this way, the transport of charge carriers in the first transport layer 121 of each sub-cell 15 along the second direction can be further reduced, thereby further reducing the non-recombination loss of charge carriers. However, it is not limited to this. The third sub-section 141 may not cut off the first transport layer 121 along the first direction to increase the applicability of different scenarios.

[0093] As shown in FIG3c, in some embodiments, the second electrode layer 14 of each sub-cell 15 includes a plurality of third sub-sections 141. The plurality of third sub-sections 141 extend along a third direction and are arranged along a fourth direction intersecting the third direction. Both the third and fourth directions are parallel to the plane of the substrate 10. Thus, the arrangement of the plurality of third sub-sections 141 can further increase the light transmittance of the second transport layer 122 and further reduce the transport of charge carriers in the second transport layer 122 along the fourth direction, as well as the bulk resistance of the second transport layer 122.

[0094] Here, the third direction can be the same as the first direction, and the fourth direction can be the same as the second direction. However, it is not limited to this; the first direction can also intersect with the first direction, and the second direction can also intersect with the second direction.

[0095] As shown in Figure 3c, in some embodiments, in the third direction, the two end sidewalls of the third sub-section 141 are flush with the two end sidewalls of the second transport layer 122, respectively. That is, the third sub-section 141 cuts off the second transport layer 122 along the first direction. In this way, the transport of charge carriers in the second transport layer 122 of each sub-cell 15 along the second direction can be further reduced, thereby further reducing the non-recombination loss of charge carriers. However, it is not limited to this. The third sub-section 141 may also not cut off the second transport layer 122 along the first direction to increase the applicability of different scenarios.

[0096] In some embodiments, the width of the first sub-part 131 in the second direction and / or the width of the third sub-part 141 in the fourth direction can be between 20 μm and 40 μm (including endpoint values), such as 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, etc.; the distance between two adjacent first sub-parts 131 and / or two adjacent third sub-parts 141 can be between 0.5 mm and 3 mm (including endpoint values), such as 0.5 mm, 1 mm, 2 mm, 3 mm, etc., when on the upper Within the aforementioned range, the area occupied by the first sub-part 131 and / or the third sub-part 141 can be effectively controlled by controlling the width of the first sub-part 131 and / or the third sub-part 141, as well as the spacing between two adjacent first sub-parts 131 and / or third sub-parts 141. This improves the light transmittance of the first transport layer 121 and / or the second transport layer 122 without reducing the vertical transport of charge carriers within the first transport layer 121 and / or the second transport layer 122, thereby avoiding a reduction in the turn-on voltage of the solar cell.

[0097] The first sub-part 131 shown in Figures 3b and 3c extends along a straight line in a first direction, and the third sub-part 141 extends along a straight line in a third direction. However, it is not limited to this; the first sub-part 131 and / or the third sub-part 141 may also extend along broken lines or curves to increase the applicable scenarios.

[0098] As shown in Figures 2e and 2f, in some embodiments, the solar cell further includes a passivation layer 16, which is located at least between the first transport layer 121 and the light-absorbing layer 13. The passivation layer 16 provided in this application is located between the first sub-section 131 and the first transport layer 121, and between the second sub-section 132 and the first transport layer 121. The passivation layer 16 reduces interface defects between the first sub-section 131 and the second sub-section 132 and the first transport layer 121, reducing the probability of carriers being trapped during transport, thereby improving carrier transport efficiency.

[0099] As shown in Figure 2e, in some embodiments, where the lower surface of the first sub-part 131 is flush with the lower surface of the first transmission layer 121 and the first sub-part 131 penetrates the first transmission layer 121, the passivation layer 16 may also cover a portion of the first electrode layer 11 located below the first sub-part 131. However, this is not the only possibility; the passivation layer 16 may also not cover the portion of the first electrode layer 11 located below the first sub-part 131 to expand the applicable scenarios.

[0100] In some embodiments, the material of the passivation layer 16 may be one or a combination of SAM self-assembled small molecules, PMP polymer molecules, or other known passivation materials.

[0101] In some embodiments, the light-absorbing layer 13 can be formed on the first transport layer 121 by a wet coating process. In some embodiments, the light-absorbing layer 13 is a perovskite light-absorbing layer. In some embodiments of this application, the perovskite light-absorbing layer includes a first sub-part 131 whose lower surface is lower than the upper surface of the first transport layer 121, which improves the crystallinity of the perovskite light-absorbing layer, suppresses the non-radiative recombination loss of charge carriers in the perovskite light-absorbing layer, thereby improving the carrier transport efficiency and thus improving the photoelectric performance of the solar cell.

[0102] This application also provides a method for manufacturing a solar cell, as shown in Figure 4. The manufacturing method includes:

[0103] Step S101: Provide a substrate;

[0104] Step S102: Forming at least one sub-cell on the substrate, including: sequentially forming a first electrode layer, a light-absorbing layer, and a second electrode layer on the substrate from bottom to top, wherein the orthographic projections of the first electrode layer, the light-absorbing layer, and the second electrode layer of each sub-cell onto the substrate plane have an overlapping area; wherein,

[0105] The formation of the sub-cell further includes: forming a first transport layer between the first electrode layer and the light-absorbing layer, wherein at least one first recessed structure is formed within the first transport layer, and the orthographic projection of the first recessed structure onto the substrate plane is located in the overlapping region; the light-absorbing layer fills the first recessed structure and covers the first transport layer and the first recessed structure; and / or,

[0106] The formation of the sub-cell further includes: forming a second transport layer between the light-absorbing layer and the second electrode layer, wherein at least one second recessed structure is formed in the second transport layer, and the orthogonal projection of the second recessed structure onto the substrate plane is located in the overlapping area; the second electrode layer fills the second recessed structure and covers the second transport layer and the second recessed structure.

[0107] The manufacturing method of this application will now be described in further detail with reference to the accompanying drawings.

[0108] First, step S101 is performed, as shown in FIG5, by providing substrate 10.

[0109] In some embodiments, the substrate 10 may be made of a transparent material, such as one or more of glass, tempered glass, quartz, and organic flexible materials. The organic flexible material may include one or more of transparent polymer materials, such as polyimide, polyethylene terephthalate, and polyethersulfone resin.

[0110] Next, step S102 is performed, as shown in Figures 6 to 10 and Figure 2a, at least one sub-cell 15 is formed on the substrate 10, including: forming a first electrode layer 11, a light-absorbing layer 13, and a second electrode layer 14 sequentially from bottom to top on the substrate 10, wherein the orthographic projection of the first electrode layer 11, the light-absorbing layer 13, and the second electrode layer 14 of each sub-cell 15 onto the plane of the substrate 10 has an overlapping area 101; wherein,

[0111] The sub-cell 15 further includes: forming a first transmission layer 121 between the first electrode layer 11 and the light-absorbing layer 13, wherein at least one first recessed structure S1 is formed in the first transmission layer 121, and the orthogonal projection of the first recessed structure S1 onto the plane of the substrate 10 is located in the overlapping region 101; the light-absorbing layer 13 fills the first recessed structure S1 and covers the first transmission layer 121 and the first recessed structure S1.

[0112] In some embodiments, the first electrode layer 11 and the second electrode layer 14 can be deposited by one or more thin film deposition processes, such as chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), physical vapor deposition (PVD), atomic layer deposition (ALD), electroplating, electroless plating, sputtering, evaporation, or any combination thereof.

[0113] In some embodiments, the material of the first electrode layer 11 may be a transparent conductive material, including but not limited to one or more of indium tin oxide (ITO), aluminum zinc oxide (AZO), indium tungsten oxide (IWO), indium cerium oxide (ICO), fluorine-doped tin oxide (FTO), zinc-doped zinc oxide (IZO), and antimony-doped tin oxide (ATO), such as fluorine-doped tin oxide (FTO).

[0114] In some embodiments, the material of the second electrode layer 14 may include a metal electrode material, a carbon material, or a composite electrode material composed of a metal electrode material and a transparent electrode material; wherein, the metal electrode material includes one or more of silver, aluminum, gold, copper, titanium, chromium, nickel, platinum, and palladium, and the carbon material includes graphene, etc.

[0115] In some embodiments, the light-absorbing layer 13 can be prepared by a wet coating process. In some embodiments, the light-absorbing layer 13 may include one or more of the following: a perovskite light-absorbing layer, an amorphous silicon light-absorbing layer, a copper indium gallium selenide light-absorbing layer, a cadmium telluride light-absorbing layer, a gallium arsenide light-absorbing layer, and an organic dye light-absorbing layer. The above-mentioned light-absorbing layers can be used to prepare thin-film solar cells with a thickness on the micrometer or nanometer scale, thereby expanding the application scenarios of solar cells.

[0116] Furthermore, the light-absorbing layer 13 may include a perovskite light-absorbing layer. This configuration increases the light absorption rate of the perovskite light-absorbing layer, thereby increasing the power generation of the perovskite solar cell. In some embodiments, the molecular formula of the perovskite light-absorbing layer material satisfies ABX3 or A2CDX6. Specifically, the material of the perovskite light-absorbing layer can be an inorganic perovskite material, an organic perovskite material, or an organic-inorganic hybrid perovskite material. For example, the material of the perovskite light-absorbing layer can be CsPbI2Br, MAPbBr3, or FAPbI3.

[0117] In some embodiments, the first transport layer 121 can be an electron transport layer or a hole transport layer. The provision of an electron transport layer or a hole transport layer helps to extract and transport electron-hole pairs generated by the light-absorbing layer 13 to the corresponding electrodes, thereby improving the carrier transport capability.

[0118] The electron transport layer material is an n-type semiconductor with electron transport capabilities. Specific materials include, but are not limited to, titanium oxide (TiO2), tin oxide (SnO2), zinc oxide (ZnO), vanadium oxide (V2O5), zinc tin oxide (Zn2SnO4), and fullerene C. 60 (C 60 ), fullerene C 70 (C 70 ) and fullerene derivatives (such as [6,6]-phenyl-C61-butyrate isomethyl ester, PC 61 One or more of BM, etc., without specific restrictions here.

[0119] The hole transport layer material is a p-type semiconductor with hole transport capability. Specific materials include, but are not limited to, one or more of the following: nickel oxide (NiOx), cuprous oxide (Cu2O), molybdenum oxide (MoO3), copper iodide (CuI), cuprous thiocyanate (CuSCN), zinc oxide, 2,2',7,7'-tetratetra(N,N-p-methoxyaniline)-9, 9'-spirodifluorene (Spiro-OMeTAD), poly[bis(4-phenyl)((2,4,6-trimethylphenyl)amine] (PTAA), and [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphate (Me-4PACz), for example, nickel oxide, without specific limitations.

[0120] In some embodiments, a single sub-cell 15 can be formed on the substrate 10 by sequentially stacking a first electrode layer 11, a first transport layer 121, a light-absorbing layer 13, and a second electrode layer 14 on the substrate 10.

[0121] However, this is not the only possibility; multiple sub-cells 15 may also be formed on the substrate 10. Specifically, forming multiple sub-cells 15 on the substrate 10 includes:

[0122] A first electrode layer 11 is formed on the substrate 10, and a first trench T1 extending along the fifth direction and penetrating the first electrode layer 11 is formed in the first electrode layer 11 (as shown in Figure 6).

[0123] A first transmission layer 121 is formed covering the first electrode layer 11 and the first trench T1, and at least one first recessed structure S1 is formed in the first transmission layer 121 (as shown in Figures 7 and 8).

[0124] A light-absorbing layer 13 is formed to fill the first recessed structure S1 and cover the first transmission layer 121 and the first recessed structure S1 (as shown in Figure 9);

[0125] A second trench T2 is formed that penetrates at least the light-absorbing layer 13 and the first transmission layer 121, and the second trench T2 extends along the fifth direction (as shown in Figure 10);

[0126] A second electrode layer 14 is formed, covering the light-absorbing layer 13 and filling the second trench T2. A third trench T3 is formed, extending at least through the second electrode layer 14, the light-absorbing layer 13, and the first transmission layer 121. The third trench T3 extends along the fifth direction. The first trench T1, the second trench T2, and the third trench T3 are arranged alternately along the sixth direction to divide the film layers such as the first electrode layer 11, the first transmission layer 121, the light-absorbing layer 13, and the second electrode layer 14 into multiple sub-cells 15 (as shown in Figure 2a).

[0127] Multiple sub-cells 15 are arranged along the sixth direction. Two adjacent sub-cells 15 are connected in series through a second electrode layer 14 located in the second trench T2, and two adjacent sub-cells 15 are separated by a third trench T3. In some embodiments, the first transport layer 121 also fills the first trench T1. Here, the fifth direction and the sixth direction are perpendicular or oblique and are both parallel to the plane of the substrate 10.

[0128] Referring again to Figures 7 and 8, in some embodiments, a first transport layer 121 is formed between the first electrode layer 11 and the light-absorbing layer 13, comprising:

[0129] After the formation of the first electrode layer 11 and before the formation of the light-absorbing layer 13, a first transport material layer 121' is formed on the first electrode layer 11, and a laser scribing process or a photolithography process is performed on the first transport material layer 121' to form the first transport layer 121 and at least one first recessed structure S1 located in the first transport layer 121.

[0130] The first transport material layer 121' can be formed using one or more thin film processes. Here, forming the first recessed structure S1 using photolithography means forming a photoresist layer on the first transport layer 121, performing an exposure process on the photoresist layer to form a pattern on the photoresist layer, and then using the patterned photoresist layer as a mask to etch the first transport layer 121 to transfer the pattern of the photoresist layer to the first transport layer 121.

[0131] In some embodiments, when a laser scribing process is used to form the first recessed structure S1 on the first transport material layer 121', the power range of the laser can be between 0.2W and 0.8W (inclusive), such as 0.2W, 0.25W, 0.4W, 0.6W, 0.8W, etc.; and / or the pulse frequency range of the laser can be between 200kHz and 500kHz (inclusive), such as 200kHz, 300kHz, 400kHz, 500kHz, etc.; and / or the wavelength range of the laser can be between 450nm and 600nm (inclusive), such as 450nm, 500nm, 532nm, 600nm, etc. By controlling the power, pulse frequency, and wavelength of the laser to be within the above ranges, it is possible to control that a first recessed structure S1 with a predetermined depth is obtained when forming the first recessed structure S1, without damaging the first electrode layer 11 located below the first transport layer 121.

[0132] Figures (1) to (3) in Figure 15 are top views of the first transmission layer 121 after laser scribing is performed on the first transmission material layer 121' to form the first recessed structure S1, with a laser pulse frequency of 400kHz and a wavelength of 532nm, and lasers with powers of 0.25W, 0.4W, and 0.6W respectively. The lasers with frequencies of 0.25W, 0.4W, and 0.6W did not damage the first electrode layer 11.

[0133] In other embodiments of this application, a first transport layer 121 with a first recessed structure S1 can also be formed on the first electrode layer 11 using a mask process. Here, forming the first transport layer 121 with the first recessed structure S1 using a mask process means placing a mask on the first electrode layer 11 and using the mask in conjunction with one or more coating processes to form the first transport layer 121 with the first recessed structure S1.

[0134] Referring again to FIG9, in some embodiments, a portion of the light-absorbing layer 13 fills the first recessed structure S1 to form a first sub-part 131, and a portion of the light-absorbing layer 13 covers the first transmission layer 121 and the first sub-part 131 to form a second sub-part 132. The first sub-part 131 and the second sub-part 132 are connected, and the lower surface of the first sub-part 131 is lower than the upper surface of the first transmission layer 121.

[0135] In some implementations, the vertically overlapping area of ​​the first electrode layer 11, the light-absorbing layer 13, and the second electrode layer 14 is the active area of ​​the sub-cell 15, that is, the orthographic projection of the active area of ​​the sub-cell 15 onto the plane of the substrate 10 coincides with the overlapping area 101; between two adjacent sub-cells 15, the area where the first trench T1, the second trench T2, and the third trench T3 are located is the dead area of ​​the sub-cell 15, and the first recessed structure S1 and the first sub-part 131 are located within the active area of ​​the sub-cell 15.

[0136] In some embodiments of this application, the light-absorbing layer 13 includes a first sub-part 131 filling the first recessed structure S1, and the lower surface of the first sub-part 131 is lower than the upper surface of the first transport layer 121. Thus, the presence of the first sub-part 131 partially thins the first transport layer 121, reducing its bulk resistance and consequently the overall resistance of the solar cell. Furthermore, when incident light enters from the side of the substrate 10 where the first electrode layer 11 and the first transport layer 121 are located and reaches the light-absorbing layer 13, the parasitic absorption of the incident light by the first transport layer 121 is reduced, increasing its transmittance and consequently increasing the light absorption rate of the light-absorbing layer 13. Since the first sub-part 131 is located in the active region of the sub-cell 15, it effectively increases the light absorption rate of the light-absorbing layer 13 in the active region, thereby contributing to improved power generation of the solar cell. In addition, the presence of the first sub-part 131 can block some of the lateral transport of charge carriers within the first transport layer 121, thereby reducing non-recombination losses of charge carriers.

[0137] In some embodiments, the ratio of the thickness of the first sub-part 131 to the thickness of the first transport layer 121 in the direction perpendicular to the plane of the substrate 10 is between 0.2 and 1 (including the endpoint value), such as 0.2, 0.5, 0.7, 0.8, 0.9, 1, etc. This increases the applicability of different scenarios. When it is within the above range, the thickness of the first sub-part 131 can be controlled by controlling the depth of the first recessed structure S1. This increases the light transmittance of the first transport layer 121 while effectively controlling the lateral transport of charge carriers in the first transport layer 121 and the bulk resistance of the first transport layer 121.

[0138] As shown in Figure 2a, in some embodiments, the lower surface of the first sub-part 131 is flush with the lower surface of the first transport layer 121, meaning the first recessed structure S1 can penetrate the first transport layer 121. However, this is not the only possibility. As shown in Figure 2d, in other embodiments of this application, the lower surface of the first sub-part 131 may be higher than the lower surface of the first transport layer 121, meaning the first recessed structure S1 may not penetrate the first transport layer 121. Thus, in practical applications, when forming the first recessed structure S1 within the first transport layer 121 using scribing or etching processes, damage to the first electrode layer 11 located below the first transport layer 121 can be avoided, thus preventing any impact on the performance of the solar cell.

[0139] As shown in Figures 14a and 3a, in some embodiments, the cross-sectional shape of the first recessed structure S1 and the first sub-part 131 along the direction parallel to the plane of the substrate 10 includes one or a combination of circles, ellipses, polygons, irregular shapes, etc. Here, polygons may include triangles, quadrilaterals, pentagons, etc., thus increasing the applicability of different scenarios.

[0140] As shown in Figures 14b and 3b, in some embodiments, each sub-cell 15 has a plurality of first recessed structures S1 within its first transport layer 121. These first recessed structures S1 extend along a first direction and are arranged along a second direction intersecting the first direction. The light-absorbing layer 13 of each sub-cell 15 includes a plurality of first sub-parts 131 extending along the first direction and arranged along the second direction. Both the first and second directions are parallel to the plane of the substrate 10. Thus, the arrangement of the plurality of first sub-parts 131 can further increase the light transmittance of the first transport layer 121 and further reduce the transport of charge carriers within the first transport layer 121 along the second direction, as well as the bulk resistance of the first transport layer 121.

[0141] Here, the first direction can be the same as or intersect with the fifth direction, and the second direction can be the same as or intersect with the sixth direction.

[0142] As shown in Figures 14b and 3b, in some embodiments, in the first direction, the first recessed structure S1 cuts through the first transport layer 121, and the two end sidewalls of the first sub-part 131 located within the first recessed structure S1 are flush with the two end sidewalls of the first transport layer 121. Thus, due to the blocking effect of the first sub-part 131, the transport of charge carriers in the first transport layer 121 of each sub-cell 15 along the second direction can be further reduced, thereby further reducing the non-recombination loss of charge carriers. However, this is not a limitation; the first recessed structure S1 may not cut through the first transport layer 121 along the first direction to increase the applicability of different scenarios.

[0143] As shown in Figures 11 and 12, in some embodiments, forming the sub-cell 15 further includes forming a second transport layer 122 between the light-absorbing layer 13 and the second electrode layer 14, wherein at least one second recessed structure S2 is formed in the second transport layer 122, and the orthographic projection of the second recessed structure S2 onto the plane of the substrate 10 is located in the overlapping region 101.

[0144] Next, the steps shown in Figures 10 and 2a are performed on the structure shown in Figure 12 to form the structure shown in Figure 2b. As shown in Figure 2b, in some embodiments, the second trench T2 and the third trench T3 also penetrate the second transmission layer 122.

[0145] Referring again to Figures 11 and 12, in some embodiments, a second transport layer 122 is formed between the light-absorbing layer 13 and the second electrode layer 14, comprising:

[0146] After the light-absorbing layer 13 is formed and before the second electrode layer 14 is formed, a second transport material layer 122' is formed on the light-absorbing layer 13, and a laser scribing process or a photolithography process is performed on the second transport material layer 122' to form the second transport layer 122 and at least one second recessed structure S2 located in the second transport layer 122.

[0147] The second transport material layer 122' can be formed using one or more thin film processes.

[0148] In some embodiments, when a laser scribing process is performed on the second transmission material layer 122' to form the second recessed structure S2, the power range of the laser can be between 0.2W and 0.8W (inclusive), such as 0.2W, 0.25W, 0.4W, 0.6W, 0.8W, etc.; and / or the pulse frequency range of the laser can be between 200kHz and 500kHz (inclusive), such as 200kHz, 300kHz, 400kHz, 500kHz, etc.; and / or the wavelength range of the laser can be between 450nm and 600nm (inclusive), such as 450nm, 500nm, 532nm, 600nm, etc. By controlling the power, pulse frequency, and wavelength of the laser to be within the above ranges, it is possible to control that a second recessed structure S2 with a predetermined depth is obtained when forming the second recessed structure S2, without damaging the light-absorbing layer 13 located below the second transmission layer 122.

[0149] However, this is not the only option; a second transport layer 122 with a second recessed structure S2 can also be formed on the light-absorbing layer 13 using a photomask process. The steps for forming the second transport layer 122 using a photomask process and a photolithography process are similar to those for forming the first transport layer 121, and will not be described in detail here.

[0150] The second electrode layer 14 fills the second recessed structure S2 and covers the second transport layer 122 and the second recessed structure S2. As shown in FIG2b, in some embodiments, a portion of the second electrode layer 14 fills the second recessed structure S2 to form a third sub-part 141, and a portion of the second electrode layer 14 covers the third sub-part 141 and the second transport layer 122 to form a fourth sub-part 142, and the lower surface of the third sub-part 141 is lower than the upper surface of the second transport layer 122.

[0151] In some embodiments of this application, the presence of the third sub-part 141 partially thins the second transport layer 122. On the one hand, this reduces the bulk resistance of the second transport layer 122, thereby reducing the overall resistance of the solar cell. On the other hand, when incident light enters from the side of the substrate 10 where the second electrode layer 14 and the second transport layer 122 are disposed and reaches the light-absorbing layer 13, it reduces the parasitic absorption of the incident light by the second transport layer 122, increases the transmittance of the second transport layer 122, and thus increases the light absorption rate of the light-absorbing layer 13. Furthermore, since the third sub-part 141 is located in the active region of the sub-cell 15, it can effectively increase the light absorption rate of the light-absorbing layer 13 located in the active region, thereby helping to increase the power generation of the solar cell. In addition, the presence of the third sub-part 141 can block some of the lateral transport of charge carriers within the second transport layer 122, thereby reducing the non-recombination loss of charge carriers.

[0152] In some embodiments, the ratio of the thickness of the third sub-part 141 to the thickness of the second transport layer 122 in the direction perpendicular to the plane of the substrate 10 is between 0.2 and 1 (including the endpoint value), such as 0.2, 0.5, 0.7, 0.8, 0.9, 1, etc. This increases the applicability of different scenarios, and when it is within the above range, the thickness of the third sub-part 141 can be controlled by controlling the depth of the second recessed structure S2. This increases the light transmittance of the second transport layer 122 while effectively controlling the lateral transport of charge carriers in the second transport layer 122 and the bulk resistance of the second transport layer 122.

[0153] In some embodiments, the lower surface of the third sub-part 141 is flush with the lower surface of the second transport layer 122, meaning the second recessed structure S2 can penetrate the second transport layer 122. However, this is not the only possibility. As shown in FIG2d, in other embodiments of this application, the lower surface of the third sub-part 141 may also be higher than the lower surface of the second transport layer 122, meaning the second recessed structure S2 does not penetrate the second transport layer 122. Thus, in practical applications, when the second recessed structure S2 is formed in the second transport layer 122 using scribing or etching processes, the scribing process is prevented from penetrating the second transport layer 122, thereby avoiding damage to the light-absorbing layer 13 located below the second transport layer 122 and affecting the performance of the solar cell.

[0154] As shown in Figures 14a and 3a, in some embodiments, the cross-sectional shape of the third sub-part 141 along the direction parallel to the plane of the substrate 10 includes one or a combination of circles, ellipses, polygons, irregular shapes, etc., to increase scene adaptability.

[0155] As shown in Figures 14c and 3c, in some embodiments, each sub-cell 15 has a plurality of second recessed structures S2 within its second transport layer 121. These second recessed structures S2 extend along a third direction and are arranged along a fourth direction intersecting the third direction. Each sub-cell's second electrode layer 14 includes a plurality of third sub-parts 141 extending along a third direction and arranged along a fourth direction, both of which are parallel to the plane of the substrate 10. Thus, the arrangement of the plurality of third sub-parts 141 can further increase the light transmittance of the second transport layer 122 and further reduce the transport of charge carriers along the fourth direction within the second transport layer 122, as well as the bulk resistance of the second transport layer 122.

[0156] Here, the third direction can be the same as or intersect with the first direction, and the fourth direction can be the same as or intersect with the second direction.

[0157] As shown in Figures 14c and 3c, in some embodiments, in the third direction, the second recessed structure S2 cuts off the second transport layer 122, and the two end sidewalls of the third sub-part 141 are flush with the two end sidewalls of the second transport layer 122, that is, the third sub-part 141 cuts off the second transport layer 122 along the first direction. In this way, the transport of charge carriers in the second transport layer 122 of each sub-cell 15 along the second direction can be further reduced, so as to further reduce the non-recombination loss of charge carriers. However, it is not limited to this, the third sub-part 141 may not cut off the second transport layer 122 along the first direction to increase the applicability of scenarios.

[0158] In some embodiments, the second transport layer 122 can be an electron transport layer or a hole transport layer, and the first transport layer 121 and the second transport layer 122 are different. For example, the first transport layer 121 is an electron transport layer and the second transport layer 122 is a hole transport layer, or the first transport layer 121 is a hole transport layer and the second transport layer 122 is an electron transport layer. The first transport layer 121 and the second transport layer 122 can be respectively provided on both sides of the light-absorbing layer 13, or the first transport layer 121 can be provided only on one side of the light-absorbing layer 13; there is no limitation here.

[0159] As shown in Figures 10 and 2a, in an embodiment where a first recessed structure S1 is formed in the first transmission layer 121 and the light-absorbing layer 13 includes a first sub-part 131, a second recessed structure S2 may not be formed in the second transmission layer 122. However, it is not limited to this; the second transmission layer 122 may not be provided between the light-absorbing layer 13 and the second electrode layer 14.

[0160] As shown in Figures 11, 12, and 2b, in embodiments where a second recessed structure S2 is formed within the second transmission layer 122, a first recessed structure S1 may not be formed within the first transmission layer 121. However, this is not a limitation; the first transmission layer 121 may not be disposed between the first electrode layer 11 and the light-absorbing layer 13.

[0161] However, this is not the only option. As shown in Figure 2c, a first transmission layer 121 can be provided between the first electrode layer 11 and the light-absorbing layer 13, while a second transmission layer 122 can be provided between the light-absorbing layer 13 and the second electrode layer 14. A first recessed structure S1 is formed in the first transmission layer 121, the light-absorbing layer 13 includes a first sub-part 131, a second recessed structure S2 is formed in the second transmission layer 122, and the second electrode layer 14 includes a third sub-part 141. In this way, when light is simultaneously incident on both sides of the first electrode layer 11 and the second electrode layer 12 in the sub-cell 15, the presence of the first sub-part 131 and the third sub-part 141 can simultaneously increase the light transmittance of the first transmission layer 121 and the second transmission layer 122, and simultaneously reduce the bulk resistance of the first transmission layer 121 and the second transmission layer 122, as well as block the lateral movement of some charge carriers in the first transmission layer and the second transmission layer 122.

[0162] In some embodiments, the width of the first sub-part 131 in the second direction and / or the width of the third sub-part 141 in the fourth direction can be between 20 μm and 40 μm (including endpoint values), such as 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, etc.; the distance between two adjacent first sub-parts 131 and / or two adjacent third sub-parts 141 can be between 0.5 mm and 3 mm (including endpoint values), such as 0.5 mm, 1 mm, 2 mm, 3 mm, etc., when on the upper Within the aforementioned range, the area occupied by the first sub-part 131 and / or the third sub-part 141 can be effectively controlled by controlling the width of the first sub-part 131 and / or the third sub-part 141, as well as the spacing between two adjacent first sub-parts 131 and / or third sub-parts 141. This improves the light transmittance of the first transport layer 121 and / or the second transport layer 122 without reducing the vertical transport of charge carriers within the first transport layer 121 and / or the second transport layer 122, thereby avoiding a reduction in the turn-on voltage of the solar cell. Figures 3b and 3c show the first sub-part 131 extending in a straight line in the first direction, and the third sub-part 141 extending in a straight line in the third direction. However, this is not a limitation; the first sub-part 131 and / or the third sub-part 141 can also extend along broken lines or curves to increase the applicable scenarios.

[0163] As shown in FIG13, in another embodiment of this application, after forming the first transport layer 121 and the first recessed structure S1 located within the first transport layer 121, and before forming the light-absorbing layer 13, the method further includes: forming a passivation layer 16, the passivation layer 16 at least covering the upper surface of the first transport layer 121 and the surface exposed by the first recessed structure S1. Thus, after the subsequent formation of the light-absorbing layer 13, the passivation layer 16 is at least located between the light-absorbing layer 13 and the first transport layer 121. The passivation layer 16 reduces interface defects between the first sub-part 131 and the second sub-part 132 and the first transport layer 121, reducing the probability of carriers being trapped during transport, thereby improving carrier transport efficiency.

[0164] Referring again to FIG13, in some embodiments, when the first recessed structure S1 penetrates the first transmission layer 121, the passivation layer 16 may cover the upper surface of the first transmission layer 121, the sidewalls of the first recessed structure S1, and the first electrode layer 11 exposed by the first recessed structure S1. Next, the steps shown in FIG10 and FIG2a are performed on the structure shown in FIG13 to form the structure shown in FIG2e, where the passivation layer 16 is located between the first sub-part 131 and the second sub-part 132 and the first transmission layer 121, and covers a portion of the first electrode layer 11 located in the first sub-part 131.

[0165] However, it is not limited to this. Alternatively, part of the passivation layer 16 covering the first electrode layer 11 can be removed, and the resulting passivation layer 16 covers the upper surface of the first transmission layer 121 and the sidewall of the first recessed structure S1 to increase the applicable scenarios.

[0166] As shown in Figure 2f, in some other embodiments of this application, when the first recessed structure S1 does not penetrate the first transmission layer 121, the passivation layer 16 can cover the upper surface of the first transmission layer 121 and the inner wall of the first recessed structure S1.

[0167] In some embodiments, the material of the passivation layer 16 may be one or a combination of SAM self-assembled small molecules, PMP polymer molecules, or other known passivation materials.

[0168] In some embodiments, the light-absorbing layer 13 can be formed on the first transport layer 121 by a wet coating process. In some embodiments, the light-absorbing layer 13 is a perovskite light-absorbing layer. In some embodiments of this application, the perovskite light-absorbing layer includes a first sub-part 131 whose lower surface is lower than the upper surface of the first transport layer 121, which improves the crystallinity of the perovskite light-absorbing layer, suppresses the non-radiative recombination loss of charge carriers in the perovskite light-absorbing layer, thereby improving the carrier transport efficiency and thus improving the photoelectric performance of the solar cell.

[0169] The present application will be described in further detail below with reference to specific embodiments, but the embodiments of the present application are not limited thereto.

[0170] Example 1:

[0171] Example 1 corresponds to the structure shown in Figure 9 of this application. The preparation process of Example 1 is as follows:

[0172] (1) Take a piece of 30cm*30cm conductive glass, wherein fluorine-doped tin oxide (FTO) is formed on the conductive glass, and serve as a substrate 10 on which the first electrode layer 11 is formed.

[0173] (2) An infrared laser is used to perform a scribing process to form the first trench T1 that penetrates the FTO layer. The width of the first trench T1 is about 30 μm. The entire glass is divided into 35 sub-cells along the long side. The series resistance of different sub-cells is greater than 10 Ω. The upper and lower 10 mm are used as the component welding area. Then, the etched conductive glass surface is cleaned twice with acetone and isopropanol, immersed in deionized water and ultrasonically treated for 10 min, dried in a forced-air drying oven, and placed in a drying room (humidity below 2%).

[0174] (3) The cleaned conductive glass is placed in a magnetron sputtering device to deposit a hole transport layer (as the first transport layer 121), wherein the hole transport layer is made of nickel oxide and has a thickness of about 15nm.

[0175] (4) A scribing process is performed using 4.2W picosecond green light to etch the hole transport layer in the active area of ​​each sub-cell, forming five first recessed structures that penetrate the hole transport layer on each sub-cell.

[0176] (5) A layer of FAPbI3 (as a perovskite light-absorbing layer) was coated on the hole transport layer using a slit coating process. Then, the perovskite light-absorbing layer was transferred to a vacuum pump and evacuated for 50 seconds at a vacuum level of 15 Pa. Next, the perovskite light-absorbing layer was transferred to a sealed space and small molecule amines were introduced. The perovskite light-absorbing layer was then annealed at 150°C for 10 minutes to obtain a perovskite light-absorbing layer dry film with a thickness of 550 nm. Then, the perovskite light-absorbing layer dry film was placed in an environment with a humidity of 2% and a temperature of 25°C and left to stand for 10 hours.

[0177] Comparative Example 1:

[0178] Steps (1) to (3) and step (5) are the same as in Example 1, except that Comparative Example 1 does not form a first recessed structure in the first transmission layer.

[0179] The fluorescence intensity of the perovskite absorbing layer in Example 1 and Comparative Example 1 was measured using a fluorescence spectrometer, and the light absorption intensity of the perovskite absorbing layer in Example 1 and Comparative Example 1 was measured using a UV-Vis spectrometer. As shown in Figures 16a and 16b, the solar cell structure described in this application can significantly improve the fluorescence intensity and light absorption intensity of the perovskite absorbing layer.

[0180] The performance of the solar cells in Comparative Example 1 and Example 1 was tested under standard simulated sunlight (AM1.5G, 100mW / cm2) to obtain IV curves. Based on the IV curves and data from the testing equipment, the short-circuit current Jsc (unit: mA / cm2) can be obtained. 2 The open-circuit voltage Voc (unit: V), maximum light output current Jmpp (unit: mA), and maximum light output voltage Vmpp (unit: V) are calculated. The fill factor FF of the battery is calculated using the formula FF = Jsc × Voc / (Jmpp × Vmpp), in percentage. The photoelectric conversion efficiency PCE of the battery is calculated using the formula PCE = Jsc × Voc × FF / Pin; Pin represents the input power of the incident light (unit: mW). Detailed test results are shown in Table 1.

[0181] Table 1:

[0182] As can be seen from the table above, compared with Comparative Example 1, the solar cell manufactured using the manufacturing method described in this application can significantly improve the photoelectric conversion efficiency of the solar cell.

[0183] The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A solar cell, comprising: A substrate, and at least one sub-cell located on the substrate, the sub-cell comprising at least a first electrode layer, a light-absorbing layer, and a second electrode layer stacked sequentially from bottom to top on the substrate, wherein the orthographic projections of the first electrode layer, the light-absorbing layer, and the second electrode layer of each sub-cell onto the plane of the substrate have an overlapping area; wherein... The sub-cell further includes a first transmission layer located between the first electrode layer and the light-absorbing layer. The light-absorbing layer includes a first sub-part and a second sub-part connected together. The lower surface of the first sub-part is lower than the upper surface of the first transmission layer. The second sub-part covers the first transmission layer and the first sub-part. The orthographic projection of the first sub-part onto the substrate plane falls into the overlapping area; and / or... The sub-cell further includes a second transport layer located between the light-absorbing layer and the second electrode layer. The second electrode layer includes a third sub-part and a fourth sub-part connected together. The lower surface of the third sub-part is lower than the upper surface of the second transport layer. The fourth sub-part covers the second transport layer and the third sub-part. The orthographic projection of the third sub-part onto the substrate plane falls into the overlapping area.

2. The solar cell according to claim 1, wherein in a direction perpendicular to the plane of the substrate, the ratio of the thickness of the first sub-part to the thickness of the first transmission layer is between 0.2 and 1, and / or the ratio of the thickness of the third sub-part to the thickness of the second transmission layer is between 0.2 and 1.

3. The solar cell according to claim 1 or 2, wherein the lower surface of the first sub-part is higher than the lower surface of the first transmission layer, and / or the lower surface of the third sub-part is higher than the lower surface of the second transmission layer.

4. The solar cell according to any one of claims 1-3, wherein the cross-sectional shape of the first sub-part along a direction parallel to the plane of the substrate includes one or a combination of a circle, an ellipse, a polygon, and an irregular shape, and / or the cross-sectional shape of the third sub-part includes one or a combination of a circle, an ellipse, a polygon, and an irregular shape.

5. The solar cell according to any one of claims 1-4, wherein the light-absorbing layer of each sub-cell comprises a plurality of first sub-parts, the plurality of first sub-parts extending along a first direction and arranged along a second direction intersecting the first direction, wherein both the first direction and the second direction are parallel to the substrate plane; and / or, Each of the sub-cells has a second electrode layer comprising a plurality of third sub-sections extending along a third direction and arranged along a fourth direction intersecting the third direction, both of which are parallel to the substrate plane.

6. The solar cell according to claim 5, wherein, in the first direction, the two end sidewalls of the first sub-part are respectively flush with the two end sidewalls of the first transmission layer, and / or, In the third direction, the two end sidewalls of the third sub-part are flush with the two end sidewalls of the second transmission layer.

7. The solar cell according to claim 1, further comprising: A passivation layer, wherein the passivation layer is located at least between the first transmission layer and the light-absorbing layer.

8. The solar cell according to any one of claims 1-7, wherein the light-absorbing layer is a perovskite light-absorbing layer.

9. The solar cell according to any one of claims 1-8, wherein the first transport layer is an electron transport layer or a hole transport layer, and / or the second transport layer is an electron transport layer or a hole transport layer.

10. A method for manufacturing a solar cell, comprising: Provide substrate; Forming at least one sub-cell on the substrate includes: sequentially forming a first electrode layer, a light-absorbing layer, and a second electrode layer on the substrate from bottom to top, wherein the first electrode layer, the light-absorbing layer, and the second electrode layer of each sub-cell have overlapping areas when projected onto the plane of the substrate; wherein... Forming the sub-cell further includes: forming a first transport layer between the first electrode layer and the light-absorbing layer, wherein at least one first recessed structure is formed within the first transport layer, and the orthographic projection of the first recessed structure onto the substrate plane is located in the overlapping region; the light-absorbing layer fills the first recessed structure and covers the first transport layer and the first recessed structure; and / or, The formation of the sub-cell further includes: forming a second transport layer between the light-absorbing layer and the second electrode layer, wherein at least one second recessed structure is formed in the second transport layer, and the orthogonal projection of the second recessed structure onto the substrate plane is located in the overlapping area; the second electrode layer fills the second recessed structure and covers the second transport layer and the second recessed structure.

11. The manufacturing method according to claim 10, wherein a second transport layer is formed between the light-absorbing layer and the second electrode layer, comprising: After the first electrode layer is formed and before the light-absorbing layer is formed, a first transmission layer with the first recessed structure inside is formed on the first electrode layer using a mask process. Alternatively, a first transport material layer may be formed on the first electrode layer, and a laser scribing process or a photolithography process may be performed on the first transport material layer to form the first transport layer and at least one of the first recessed structures located within the first transport layer. And / or, A second transport layer is formed between the light-absorbing layer and the second electrode layer, comprising: After the light-absorbing layer is formed and before the second electrode layer is formed, a second transmission layer with the second recessed structure inside is formed on the light-absorbing layer using a mask process. Alternatively, a second transport material layer may be formed on the light-absorbing layer, and a laser scribing or photolithography process may be performed on the second transport material layer to form the second transport layer and at least one second recessed structure located within the second transport layer.

12. The manufacturing method according to claim 11, wherein in the step of performing a laser scribing process to form the first recessed structure and / or the second recessed structure, the power of the laser is in the range of 0.2W to 0.8W; and / or the pulse frequency of the laser is in the range of 200kHz to 500kHz; and / or the wavelength of the laser is in the range of 450nm to 600nm.

13. The manufacturing method according to claim 10, wherein after forming the first transmission layer and the first recessed structure located within the first transmission layer, and before forming the light-absorbing layer, the method further comprises: A passivation layer is formed, which at least covers the upper surface of the first transmission layer and the surface exposed by the first recessed structure.

14. A photovoltaic module comprising a solar cell as claimed in any one of claims 1 to 9.

15. An electrical appliance comprising a photovoltaic module as described in claim 14.

16. A power generation device, the power generation device comprising the photovoltaic module as described in claim 14.

Images