Stacked battery and method of manufacturing the same, photovoltaic module

Abstract

This disclosure relates to the photovoltaic field, providing a tandem solar cell and its manufacturing method, as well as a photovoltaic module. The tandem solar cell includes: a bottom cell and a perovskite cell stacked together; a passivation layer located between the bottom cell and the perovskite cell, and the passivation layer having at least one recessed region recessed towards the bottom cell on the surface near the perovskite cell; and a conductive portion located in the recessed region, wherein the passivation layer and the conductive portion together constitute a connecting layer, and the bottom cell and the perovskite cell are electrically connected through the connecting layer. The width of the recessed region is 500 nm to 800 nm, and / or the width of the conductive portion is 200 nm to 400 nm, which is at least beneficial to improving the power conversion efficiency of the tandem solar cell.

Description

Technical Field

[0001] This disclosure relates to the photovoltaic field, and in particular to a tandem cell and its manufacturing method, and a photovoltaic module. Background Technology

[0002] With the gradual depletion of fossil fuels, photovoltaic cells are becoming increasingly widely used as a new energy alternative. A photovoltaic cell is a device that converts solar energy into electrical energy. It utilizes the photovoltaic principle to generate charge carriers, which are then extracted using electrodes, thus facilitating the efficient use of electrical energy.

[0003] Current photovoltaic cells mainly include BC cells (Back Contact), TOPCON (Tunnel Oxide Passivated Contact) cells, PERC cells (Passivated emitter and rear cell), heterojunction cells (Heterojunction with Intrinsic Thin-film, abbreviated as HIT or HJT), and perovskite tandem cells, etc. Summary of the Invention

[0004] This disclosure provides a tandem solar cell and its manufacturing method, as well as a photovoltaic module, which at least helps to improve the power conversion efficiency of the tandem solar cell.

[0005] This disclosure provides a stacked solar cell, comprising: a base cell and a perovskite cell stacked together; a passivation layer located between the base cell and the perovskite cell, wherein the passivation layer has at least one recessed region recessed toward the base cell near the surface of the perovskite cell; and a conductive portion located in the recessed region, wherein the passivation layer and the conductive portion together constitute a connecting layer, and the base cell and the perovskite cell are electrically connected through the connecting layer; wherein the width of the recessed region is 500 nm to 800 nm, and / or the width of the conductive portion is 200 nm to 400 nm.

[0006] Optionally, the surface of the bottom cell near the passivation layer has a first textured structure, and the surface of the passivation layer near the perovskite cell has a second textured structure, the second textured structure having the recessed area.

[0007] Optionally, along the first direction, the depth of the recessed area recessed toward the bottom cell is 0.1 μm to 1 μm, and the first direction is the stacking direction of the bottom cell and the perovskite cell; and / or, the area of ​​the conductive portion on the surface of the passivation layer near the perovskite cell accounts for 50% to 70%.

[0008] Optionally, the perovskite solar cell includes a hole transport layer, a perovskite layer, and an electron transport layer stacked together; the bottom cell includes a substrate and a doped conductive portion stacked together; wherein, the passivation layer is located between the hole transport layer and the doped conductive portion, and the doped conductive portion is doped with an N-type dopant element.

[0009] Optionally, the perovskite solar cell includes an electron transport layer, a perovskite layer, and a hole transport layer stacked together; the bottom cell includes a substrate and a doped conductive portion stacked together; wherein the passivation layer is located between the electron transport layer and the doped conductive portion, and the doped conductive portion is doped with a p-type dopant element.

[0010] Optionally, the doped conductive portion and the passivation layer are doped with the same type of doping element, and along the direction from the bottom cell to the perovskite cell, the passivation layer includes at least a stacked A layer and a (A+1) layer, the doping concentration of the doping element in the A layer is lower than the doping concentration of the doping element in the (A+1) layer, where A is a positive integer greater than or equal to 1.

[0011] Optionally, along the direction from the bottom cell to the perovskite cell, the doped conductive portion includes at least a stacked portion B and a (B+1) portion, wherein the doping concentration of the dopant element in the portion B is lower than the doping concentration of the dopant element in the (B+1) portion, and B is a positive integer greater than or equal to 1.

[0012] Optionally, the perovskite solar cell further includes a repair layer located on the side of the perovskite layer away from the passivation layer.

[0013] Optionally, the material of the passivation layer includes at least one of aluminum fluoride, lithium fluoride, magnesium fluoride, cesium fluoride, sodium fluoride, potassium fluoride, calcium fluoride, aluminum oxide, silicon oxide, silicon nitride, silicon fluoride, silicon oxyfluoride, silicon carbon oxynitride, or aluminum oxynitride.

[0014] Optionally, the perovskite solar cell includes a hole transport layer, a perovskite layer, and an electron transport layer stacked along a first direction; wherein the electron transport layer includes an interface layer and a conductive layer located on the side of the interface layer away from the perovskite layer, and the thickness of the interface layer is less than or equal to the thickness of the conductive layer along the first direction.

[0015] Optionally, the perovskite solar cell includes a first transparent conductive layer, a hole transport layer, a perovskite layer, and an electron transport layer stacked along a first direction; wherein, along the first direction, the thickness of the hole transport layer is less than or equal to the thickness of the first transparent conductive layer.

[0016] Optionally, the perovskite solar cell includes a first transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, and a second transparent conductive layer stacked along a first direction; wherein the surface of the first transparent conductive layer away from the hole transport layer has a plurality of protrusions; and / or, the surface of the second transparent conductive layer away from the electron transport layer has a plurality of protrusions.

[0017] This disclosure also provides a method for manufacturing a tandem solar cell, comprising: providing a base cell; forming a passivation layer on one surface of the base cell, wherein the passivation layer has at least one recessed region recessed toward the base cell on the surface away from the base cell; forming a conductive portion on the recessed region, wherein the passivation layer and the conductive portion together constitute a connecting layer; wherein the width of the recessed region is 500 nm to 800 nm, and / or the width of the conductive portion is 200 nm to 400 nm; and forming a perovskite solar cell on the side of the connecting layer away from the base cell.

[0018] Optionally, the surface of the bottom battery near the passivation layer presents a first textured structure; the method of forming the passivation layer includes: forming the passivation layer on the first textured structure using a deposition process, so that the surface of the passivation layer away from the bottom battery presents a second textured structure, and the second textured structure has the recessed area.

[0019] Optionally, the method for forming the perovskite solar cell includes: using a spin coating process to sequentially form a hole transport layer and a perovskite layer on at least the side of the connecting layer away from the bottom cell.

[0020] Optionally, the method for forming the perovskite solar cell further includes: using a spin coating process to form a repair layer on the side of the perovskite layer away from the hole transport layer.

[0021] Optionally, the method for forming the perovskite solar cell further includes: using a deposition process to form an electron transport layer on the side of the perovskite layer away from the hole transport layer.

[0022] Optionally, the method of forming the perovskite solar cell includes: sequentially forming an electron transport layer, a perovskite layer, and a hole transport layer on at least the side of the interconnecting layer away from the bottom cell.

[0023] This disclosure also provides a photovoltaic module, comprising: a battery string, formed by connecting a plurality of stacked batteries as described in any one of the preceding claims, or formed by connecting a plurality of stacked batteries formed by a manufacturing method of the stacked batteries as described in any one of the preceding claims; an encapsulating film for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulating film opposite to the battery string.

[0024] The technical solution provided in this disclosure has at least the following advantages: First, the passivation layer helps reduce the risk of recombination of charge carriers generated in the base cell near the perovskite cell surface, thereby improving carrier lifetime and reducing the series resistance between the base and perovskite cells. Furthermore, the recessed areas on the passivation layer near the perovskite cell surface enhance the light-trapping effect of the passivation layer, allowing more light to pass through and be absorbed and utilized by the base cell, thus improving the photoelectric conversion efficiency of the base cell. Even further, the conductive portion fills the recessed areas, improving the flatness of the connecting layer formed by the passivation layer and the conductive portion near the perovskite cell surface. This improves the film quality of the perovskite cell on the connecting layer without affecting the light-trapping efficiency of the passivation layer, and further enhances the conductivity of the connecting layer through the conductive portion, thereby further reducing the series resistance between the base and perovskite cells. In addition, the conductive portion can reflect some light, allowing it to propagate back into the perovskite cell, thus improving the light absorption and utilization rate of the tandem cell. This is beneficial for improving the power conversion efficiency of tandem batteries from multiple aspects. Attached Figure Description

[0025] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, 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.

[0026] Figure 1 This is a schematic diagram of a first partial cross-sectional structure of a stacked battery provided in an embodiment of the present disclosure. Figure 2 This is a partial top view of a stacked battery provided in an embodiment of the present disclosure. Figure 3 A top view schematic diagram of a recessed region in a stacked battery provided in an embodiment of this disclosure; Figure 4 This is a schematic diagram of a second partial cross-sectional structure of a stacked battery provided in an embodiment of the present disclosure; Figure 5 This is a schematic diagram of a third partial cross-sectional structure of a stacked battery provided in an embodiment of the present disclosure. Figure 6 This is a schematic diagram of a fourth partial cross-sectional structure of a stacked battery provided in an embodiment of the present disclosure; Figure 7 This is a schematic diagram of a fifth partial cross-sectional structure of a stacked battery provided in an embodiment of the present disclosure; Figure 8 This is a partial top view of a second transparent conductive layer in a stacked battery according to an embodiment of the present disclosure. Figure 9 This is a schematic diagram of a sixth partial cross-sectional structure of a stacked battery provided in an embodiment of the present disclosure; Figure 10 A process flow diagram of a method for manufacturing a stacked battery according to another embodiment of this disclosure; Figure 11 This is a partial cross-sectional structural diagram of a stacked battery after the passivation layer has been formed in a manufacturing method of the stacked battery provided in another embodiment of the present disclosure; Figure 12 This is a partial cross-sectional view of a method for manufacturing a stacked battery according to another embodiment of the present disclosure, after the conductive portion has been formed. Figure 13 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in yet another embodiment of this disclosure; Figure 14 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in yet another embodiment of the present disclosure.

[0027] Explanation of reference numerals in the attached figures: 100, Base cell; 110, First textured structure; 120, Substrate; 130, Doped conductive part; 101, Perovskite cell; 111, Hole transport layer; 121, Perovskite layer; 131, Electron transport layer; 1311, Interface layer; 1312, Conductive layer; 141, Repair layer; 151, Second transparent conductive layer; 1511, Protrusion; 161, First transparent conductive layer; 102, Passivation layer; 112, Recessed area; 122, Second textured structure; 103, Conductive part; 123, Connecting layer; 114, First electrode; 124, Second electrode; 40, Stacked cell; 41, Encapsulating film; 42, Cover plate; 43, Solder ribbon. Detailed Implementation

[0028] As can be seen from the background technology, the power conversion efficiency of tandem batteries needs to be improved.

[0029] This disclosure provides a tandem solar cell and its manufacturing method, as well as a photovoltaic module. In the tandem solar cell, firstly, the passivation layer helps reduce the risk of recombination of charge carriers generated in the bottom cell near the surface of the perovskite cell, and also reduces the risk of recombination of charge carriers generated in the perovskite cell near the surface of the bottom cell, thereby improving the carrier lifetime and reducing the series resistance between the bottom cell and the perovskite cell. Furthermore, the recessed areas on the surface of the passivation layer near the perovskite cell help improve the light-trapping effect of the passivation layer, allowing more light to pass through the passivation layer and be absorbed and utilized by the bottom cell, thus improving the photoelectric conversion efficiency of the bottom cell. Even further, the conductive portion has a certain filling effect on the recessed areas, which can improve the flatness of the connecting layer formed by the passivation layer and the conductive portion near the surface of the perovskite cell, thereby improving the film quality of the perovskite cell located on the connecting layer. This does not affect the light-trapping efficiency of the passivation layer, and the conductive portion can further improve the conductivity of the connecting layer, thereby further reducing the series resistance between the bottom cell and the perovskite cell. Furthermore, the conductive parts can reflect some of the light, allowing it to propagate back into the perovskite solar cell, thereby improving the light absorption and utilization rate of the tandem solar cell. This contributes to improving the power conversion efficiency of the tandem solar cell from multiple perspectives.

[0030] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "multiple" means two or more (including two), unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0031] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0032] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0033] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of this disclosure and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of this disclosure. For example, if the device or element in the illustration is inverted, then the element described as "below," "under," "below," or "bottom" of other elements or features will be oriented "above" or "top" of said other elements or features. Therefore, the term "below" may, depending on the context in which the term is used, encompass both above and below orientations, which will be obvious to those skilled in the art. Materials may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatial relative descriptive terms used herein may be interpreted accordingly.

[0034] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0035] In the description of the embodiments of this disclosure, electrical connection between one component and another means that both components are made of conductive materials, and the two components are in direct contact and connected or connected via other conductive materials. Therefore, when the photovoltaic module is generating electricity, current flows between the two components. Electrical contact between one component and another means that the two components are not only in contact, but also, because both components are made of conductive materials, current flows between the two components when the photovoltaic module is generating electricity.

[0036] In the description of embodiments of this disclosure, the terms "about," "approximately," "roughly," or "about" for a numerical value referring to a specific parameter include the numerical value, and those skilled in the art will understand that the deviation from the numerical value is within acceptable tolerances of the specific parameter. For example, "about" or "about" for a numerical value may include additional numerical values ​​that are in the range of 90.0% to 110.0% of the numerical value, such as in the range of 95.0% to 105.0%, 97.5% to 102.5%, 99.0% to 101.0%, 99.5% to 100.5%, or 99.9% to 100.1%.

[0037] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and / or area of ​​layers, films, panels, regions, etc., are enlarged for better understanding and ease of description. Throughout the specification, the same reference numerals denote the same elements. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor on a portion of the edge of the entire surface.

[0038] In the description of embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. When a component (such as a layer, film, region, or substrate) is described as being on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be an intermediate component between the two components. Conversely, when a component is described as being on the surface of another component, or a component is "directly" on another component, or another component is formed or disposed on the surface of a component, it indicates that there is no intermediate component between the two components. For simplicity and clarity, various components may be drawn at any scale. In the drawings, some components may be omitted for simplicity.

[0039] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "the component" is also intended to include the plural form unless the context clearly indicates otherwise.

[0040] The “components” mentioned above can refer to layers, films, regions, parts, structures, etc.

[0041] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the embodiments. However, the technical solutions claimed in the embodiments of this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0042] This disclosure provides an embodiment of a stacked battery, which will be described in detail below with reference to the accompanying drawings.

[0043] refer to Figure 1 , Figure 1 This is a partial cross-sectional view of a first embodiment of the tandem solar cell provided in this disclosure. The tandem solar cell includes: a bottom cell 100 and a perovskite cell 101 stacked together; a passivation layer 102 located between the bottom cell 100 and the perovskite cell 101, and the surface of the passivation layer 102 near the perovskite cell 101 has at least one recessed region 112 that is recessed into the bottom cell 100; and a conductive portion 103 located in the recessed region 112. The passivation layer 102 and the conductive portion 103 together constitute a connecting layer 123, and the bottom cell 100 and the perovskite cell 101 are electrically connected through the connecting layer 123.

[0044] First, the passivation layer 102 facilitates the passivation of the surfaces of the bottom cell 100 and the perovskite cell 101 that are close to each other, thereby reducing the risk of recombination of charge carriers generated in the bottom cell 100 on the surface of the bottom cell 100 close to the perovskite cell 101, and reducing the risk of recombination of charge carriers generated in the perovskite cell 101 on the surface of the perovskite cell 101 close to the bottom cell 100, thereby improving the carrier lifetime and reducing the series resistance between the bottom cell 100 and the perovskite cell 101. Furthermore, the passivation layer 102 is designed to have at least one recessed region 112 that is recessed into the bottom cell 100 on the surface of the perovskite cell 101. This is beneficial to improve the roughness of the surface of the passivation layer 102 near the perovskite cell 101, thereby enhancing the light trapping effect of the passivation layer 102 by means of the recessed region 112. This allows more light to pass through the passivation layer 102 and be absorbed and utilized by the bottom cell 100, thereby improving the photoelectric conversion efficiency of the bottom cell 100 and promoting the improvement of the power conversion efficiency (PCE) of the tandem cell. Furthermore, by designing the conductive portion 103 to be located in the recessed region 112, the conductive portion 103 can fill the recessed region 112 to a certain extent, improving the flatness of the connecting layer 123, which is jointly formed by the passivation layer 102 and the conductive portion 103, near the surface of the perovskite solar cell 101. This improves the film quality of the perovskite solar cell 101 located on the connecting layer 123, without affecting the light trapping efficiency of the passivation layer 102. The conductive portion 103 can also further improve the conductivity of the connecting layer 123, thereby further reducing the series resistance between the bottom cell 100 and the perovskite solar cell 101. Thus, by designing the surface morphology of the passivation layer 102 and utilizing the combined effect of the passivation layer 102 and the conductive portion 103, the power conversion efficiency of the tandem solar cell can be improved from multiple aspects.

[0045] Furthermore, for the small amount of light that does not pass through the passivation layer 102, the conductive part 103 can further reflect it, allowing that portion of the light to propagate again into the perovskite solar cell 101, where it is absorbed and utilized, thereby improving the light absorption and utilization rate of the tandem solar cell.

[0046] It is worth noting that the perovskite solar cell 101 is located on the connecting layer 123. The flatness of the surface of the connecting layer 123 affects the film quality of at least one layer of the perovskite solar cell 101 near the connecting layer 123. In other words, a higher surface roughness increases the uniformity of the film thickness formed on that surface, thus affecting the function of the film. Based on this, by using the conductive portion 103 to improve the flatness of the surface of the connecting layer 123 near the perovskite solar cell 101, i.e., reducing its surface roughness, it is beneficial to improve the film quality of the perovskite solar cell 101 located on the connecting layer 123, thereby ensuring that the perovskite solar cell 101 has good photoelectric conversion efficiency.

[0047] In some cases, before stacking the perovskite solar cell 101 on the base cell 100, the surface of the base cell 100 near the perovskite solar cell 101 is cleaned, and the surface of the base cell 100 should not be exposed to air for a long time. Based on this, the passivation layer 102 is designed to be located on the surface of the base cell 100 near the perovskite solar cell 101, which is beneficial for providing physical protection to the surface of the base cell 100 near the perovskite solar cell 101.

[0048] In some cases, compared to the current stacked batteries without passivation layers and / or conductive parts, the stacked battery provided in one embodiment of this disclosure, with the cooperation of the passivation layer 102 and the conductive part 103, has improved open-circuit voltage, short-circuit current and fill factor to varying degrees, so that the power conversion efficiency of the stacked battery reaches at least 33.45%.

[0049] It should be noted that in the stacked battery provided in one embodiment of this disclosure, there is no limitation on the number of conductive portions 103 located on the surface of the passivation layer 102 near the perovskite cell 101, nor is there any limitation on the orthographic projection morphology of a single conductive portion 103 on the bottom cell 100, as long as the conductive portion 103 has a certain filling effect on the recessed area 112.

[0050] The following will describe in more detail a stacked battery provided in an embodiment of the present disclosure with reference to the accompanying drawings.

[0051] In some embodiments, reference Figure 1 The base cell 100 can be a crystalline silicon cell, for example, a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, or an amorphous silicon solar cell. Furthermore, the cell type of the base cell 100 includes, but is not limited to, BC cells, TOPCON cells, PERC cells, or HIT / HJT cells.

[0052] Among them, BC batteries include, but are not limited to, IBC batteries (Interdigitated Back Contact), HBC batteries (Heterojunction Back Contact), TBC batteries (TOPCon Back Contact), HTBC batteries (Heterojunction TunnelOxide Passivated Back Contact), or HPBC batteries (Hybrid Passivated Back Contact).

[0053] In other embodiments, the bottom cell may also be a thin-film solar cell, wherein the thin-film solar cell includes, but is not limited to, copper indium selenide (CIGS) thin-film solar cells, gallium arsenide (GaAs) thin-film solar cells, or cadmium sulfide (CdS) thin-film solar cells.

[0054] In some embodiments, reference Figure 1 The material of the conductive part 103 may include at least one of the following metals: silver, aluminum, copper, tin, gold, lead, or nickel. Generally, metal materials can increase the reflectivity of the conductive part 103 to light, thereby reflecting as much light as possible back into the perovskite cell 101 for absorption and utilization by the perovskite cell 101, thus maximizing the light absorption and utilization rate of the tandem cell.

[0055] In some embodiments, reference Figure 1 The surface of the bottom cell 100 near the passivation layer 102 can be presented as a first texture structure 110, and the surface of the passivation layer 102 near the perovskite cell 101 is presented as a second texture structure 122, with a recessed area 112 on the second texture structure 122.

[0056] Thus, the first texture structure 110 helps to improve the surface roughness of the side of the bottom cell 100 near the passivation layer 102, thereby improving the light trapping effect of the bottom cell 100. In addition, it can also promote the surface of the passivation layer 102 near the perovskite cell 101 to present a second texture structure 122.

[0057] It is understood that the passivation layer 102 can be regarded as conformally covering the surface of the bottom cell 100 that presents the first texture structure 110, thereby making the passivation layer 102 close to the surface of the perovskite cell 101, that is, the surface of the passivation layer 102 away from the bottom cell 100 presents the second texture structure 122. In this way, the morphology of the first texture structure 110 and the second texture structure 122 can be approximately the same.

[0058] It should be noted that the morphology of at least one of the first texture structure 110 and the second texture structure 122 may include at least one of a pyramidal structure, a prismatic structure, a spherical structure, or a pen-like structure, and both the first texture structure 110 and the second texture structure 122 can be regarded as a velvety surface. Generally, the first texture structure 110 is formed in the bottom battery 100 using a texturing process.

[0059] In some embodiments, reference Figure 1Along the first direction X, the depth H8 of the recessed region 112 recessed into the bottom cell 100 can be 0.1 μm to 1 μm, where the first direction X is the stacking direction of the bottom cell 100 and the perovskite cell 101. This allows the recessed depth of the recessed region 112 to be within an appropriate range, improving the light-trapping effect of the passivation layer 102 while facilitating the formation of a suitable-sized conductive portion 103 within the recessed region 112.

[0060] It should be noted that in the same passivation layer 102, the depth H8 of different recessed regions 112 can be different and can have a large difference, but the numerical range is almost all within 0.1μm~1μm.

[0061] also, Figure 1 The surface of the passivation layer 102 away from the bottom battery 100 is presented as a second texture structure 122, and the second texture structure 122 includes a pyramid-shaped structure as an example. Based on this, the depth H8 of the recessed area 112 recessed into the bottom battery 100 can be the height difference between the top and bottom of the pyramid-shaped structure in the first direction X, and the height difference between the top and bottom of different pyramid-shaped structures is different.

[0062] In some cases, the depth H7 of the recessed region 112 recessed towards the bottom battery 100 along the first direction X can be 0.1 μm to 0.5 μm or 0.5 μm to 1 μm. Optionally, the depth H7 of the recessed region 112 recessed towards the bottom battery 100 can be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or 1 μm, etc.

[0063] In some embodiments, in conjunction with reference Figure 1 and Figure 2 , Figure 2 This is a partial top view of a stacked battery provided in an embodiment of the present disclosure. The area of ​​the conductive portion 103 on the surface of the passivation layer 102 near the perovskite battery 101 can be 50% to 70%, for example, 50% to 55%, 55% to 60%, 60% to 65%, or 65% to 70%. Optionally, the area of ​​the conductive portion 103 on the surface of the passivation layer 102 near the perovskite battery 101 can be 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, or 70%, etc.

[0064] In this way, conductive portions 103 can be provided in most of the recessed areas 112, thereby maximizing the filling effect of the conductive portions 103 on the recessed areas 112, improving the flatness of the connecting layer 123 formed by the passivation layer 102 and the conductive portions 103 near the surface of the perovskite solar cell 101, thereby improving the film quality of the perovskite solar cell 101 located on the connecting layer 123, and avoiding excessive filling of the recessed areas 112 by the conductive portions 103 so as not to affect the light trapping efficiency of the passivation layer 102. Furthermore, the conductivity of the connecting layer 123 can be maximized by utilizing the conductive portions 103 with a larger area ratio, thereby further reducing the series resistance between the bottom cell 100 and the perovskite solar cell 101.

[0065] It should be noted that the area ratio of the conductive part 103 on the surface of the passivation layer 102 near the perovskite cell 101 refers to the ratio of the positive projection area of ​​the conductive part 103 on the projection plane with a plane perpendicular to the first direction X as the projection plane to the positive projection area of ​​the passivation layer 102 on the projection plane, which can be 50% to 70%.

[0066] In some embodiments, in conjunction with reference Figure 1 and Figure 2 The width W1 of the recessed region 112 can be 500nm~800nm, for example, it can be 500nm~600nm, 600nm~700nm or 700nm~800nm. Optionally, the width W1 of the recessed region 112 can be 500nm, 510nm, 520nm, 530nm, 540nm, 550nm, 560nm, 570nm, 580nm, 590nm, 600nm, 610nm, 620nm, 630nm, 640nm, 650nm, 660nm, 670nm, 680nm, 690nm, 700nm, 710nm, 720nm, 730nm, 740nm, 750nm, 760nm, 770nm, 780nm or 800nm, etc.

[0067] In some cases, in conjunction with references Figures 1 to 3 The surface of the passivation layer 102 away from the bottom battery 100 presents a second texture structure 122. Figure 2 Taking the second texture structure 122, which includes a pyramid-shaped structure, as an example, the four edges of the pyramid-shaped structure are indicated by four diagonal lines. Two adjacent edges and the bottom of the pyramid-shaped structure constitute the side of the pyramid-shaped structure. The recessed area 112 can be regarded as a recessed area enclosed by two side surfaces of two adjacent pyramid-shaped structures.

[0068] in, Figure 3 This is a top view schematic diagram of a recessed region in a stacked battery provided in an embodiment of the present disclosure.

[0069] Based on this, taking the plane perpendicular to the first direction X as the projection plane, the width W1 of the recessed area 112 includes either the side length or the diagonal length of the orthographic projection pattern of the entire recessed area 112 on the projection plane. Figure 2 In the example, the width W1 of the recessed area 112 is taken as the diagonal length of the orthographic projection pattern of the entire recessed area 112 on the projection plane. Furthermore, Figure 2 Taking the orthographic projection pattern of the recessed area 112 on the projection surface as a relatively regular or more regular quadrilateral as an example, in this case, the width W1 of the recessed area 112 is either the side length or the diagonal length of the quadrilateral.

[0070] In practical applications, the plane perpendicular to the first direction X is used as the projection plane. The orthographic projection pattern of the entire recessed area 112 on the projection plane can also be an irregular polygon. In this case, the side length or diagonal length of the orthographic projection pattern of the entire recessed area 112 on the projection plane is not absolute, but is artificially defined to characterize the width W1 of the recessed area 112. For example, refer to... Figure 3 The orthographic projection pattern of the entire recessed area 112 on the projection surface is an irregular quadrilateral. In this case, the length W11 of the orthographic projection pattern of the entire recessed area 112 on the projection surface can be defined as the side length of the longest side of the irregular quadrilateral, the width W12 of the orthographic projection pattern of the entire recessed area 112 on the projection surface can be defined as the side length of the shortest side of the irregular quadrilateral, and the diagonal length W13 of the orthographic projection pattern of the entire recessed area 112 on the projection surface can be defined as the side length of the longest diagonal of the irregular quadrilateral. It should be understood that the above is only an exemplary description, and can be flexibly defined according to actual needs in practice.

[0071] In addition, the orthographic projection pattern of the entire recessed area 112 on the projection surface can be an irregular quadrilateral, or other irregular polygons, circles, or irregular shapes that are approximately circular. In this case, the width W1 of the recessed area 112 is selected from multiple regions with different specific areas in the orthographic projection pattern of the entire recessed area 112 on the projection surface. These regions with specific areas can be flexibly defined according to actual needs, and then the average value of the side length, diagonal, or diameter of multiple regions with different specific areas is calculated.

[0072] In some embodiments, in conjunction with reference Figure 1 and Figure 2The width W2 of the conductive portion 103 can be 200nm to 400nm. For example, it can be 200nm to 300nm or 300nm to 400nm. Optionally, the width W2 of the conductive portion 103 can be 200nm, 210nm, 220nm, 230nm, 240nm, 250nm, 260nm, 270nm, 280nm, 290nm, 300nm, 310nm, 320nm, 330nm, 340nm, 350nm, 360nm, 370nm, 380nm, 390nm, or 400nm, etc.

[0073] It should be noted that the plane perpendicular to the first direction X is used as the projection plane. Figure 2 The example shown uses an elliptical orthographic projection pattern of the conductive part 103 on the projection surface. In practical applications, the orthographic projection pattern of the conductive part on the projection surface can also be a relatively regular quadrilateral, an irregular quadrilateral, other irregular polygons, a circle, or an irregular shape that is approximately circular. Furthermore, the measurement method of the width W2 of the conductive part 103 is the same as or corresponds to the measurement method of the width W1 of the recessed area 112, and will not be described again here.

[0074] The following two examples illustrate in detail the positional relationship between a portion of the film layer in a perovskite solar cell and a portion of the film layer in a bottom cell.

[0075] In some embodiments, reference Figure 4 , Figure 4 This is a partial cross-sectional view of a second embodiment of the stacked solar cell provided in this disclosure. The perovskite solar cell 101 may include a hole transport layer 111, a perovskite layer 121, and an electron transport layer 131 stacked together. The bottom solar cell 100 may include a substrate 120 stacked together and a doped conductive portion 130. A passivation layer 102 is located between the hole transport layer 111 and the doped conductive portion 130, and the doped conductive portion 130 is doped with an N-type dopant. Thus, electrons in the bottom solar cell 100 are output through the doped conductive portion 130, and holes in the perovskite solar cell 101 are output through the hole transport layer 111. The connecting layer 123 provides a recombination channel for electrons in the bottom solar cell 100 and holes in the perovskite solar cell 101, thereby realizing the series connection of the bottom solar cell 100 and the perovskite solar cell 101.

[0076] It is worth noting that the hole transport layer 111 is generally fabricated at a relatively low temperature, such as no higher than 150°C, which helps to reduce the thermal impact of the fabrication temperature of the hole transport layer 111 on the bottom cell 100. Generally, for a bottom cell 100 with an N-type semiconductor substrate 120, i.e., a bottom cell 100 doped with N-type dopant elements, the front side of the bottom cell 100, i.e., the surface of the bottom cell 100 near the perovskite cell 101, is usually provided with a doped conductive portion 130 for electron extraction. This makes the polarity of the bottom cell 100, including the N-type semiconductor substrate, more compatible with the hole transport layer 111. The passivation layer 102 is designed to be located between the hole transport layer 111 and the doped conductive portion 130, which is more conducive to compatibility with the bottom cell 100 including the N-type semiconductor substrate, thereby improving the power conversion efficiency of the tandem cell. In addition, the hole transport layer 111 has high film stability, for example, high resistance to thermal aging and photo-aging, which helps to provide better interface protection for the bottom cell 100.

[0077] In some cases, the N-type dopant element can be at least one of group V elements such as phosphorus (P), bismuth (Bi), antimony (Sb), or arsenic (As).

[0078] In other embodiments, reference is made to... Figure 5 , Figure 5 This is a schematic diagram of a third partial cross-sectional structure of a tandem solar cell provided in an embodiment of the present disclosure. The perovskite solar cell 101 may include an electron transport layer 131, a perovskite layer 121, and a hole transport layer 111 stacked together. The bottom solar cell 100 may include a substrate 120 stacked together and a doped conductive portion 130. A passivation layer 102 is located between the electron transport layer 131 and the doped conductive portion 130, and the doped conductive portion 130 is doped with a p-type dopant. Thus, holes in the bottom solar cell 100 are output through the doped conductive portion 130, and electrons in the perovskite solar cell 101 are output through the electron transport layer 131. The connecting layer 123 provides a recombination channel for holes in the bottom solar cell 100 and electrons in the perovskite solar cell 101, thereby realizing the series connection of the bottom solar cell 100 and the perovskite solar cell 101.

[0079] It is worth noting that the electron transport layer 131 has superior conductivity. The passivation layer 102 is designed to be located between the electron transport layer 131 and the doped conductive part 130, which is more conducive to reducing the series resistance between the bottom cell 100 and the perovskite cell 101, thereby improving the power conversion efficiency of the tandem cell.

[0080] Generally speaking, for a bottom cell 100 whose substrate 120 is a P-type semiconductor substrate, that is, a bottom cell 100 doped with P-type dopant elements, the front side of the bottom cell 100, that is, the surface of the bottom cell 100 including the P-type semiconductor substrate near the perovskite cell 101, is usually provided with a doped conductive part 130 for leading out holes. This makes the polarity of the bottom cell 100 and the electron transport layer 131 more matched, which is more conducive to compatibility with the bottom cell 100 including the P-type semiconductor substrate, thereby improving the power conversion efficiency of the tandem cell.

[0081] In some cases, the p-type dopant element can be at least one of group III elements such as boron (B), aluminum (Al), gallium (Ga), or indium (In).

[0082] In both of the above embodiments, the substrate 120 can be made of an elemental semiconductor material. Specifically, the elemental semiconductor material is composed of a single element, such as silicon or germanium. The elemental semiconductor material can be monocrystalline, polycrystalline, amorphous, or microcrystalline (a state simultaneously possessing both monocrystalline and amorphous states is called microcrystalline). For example, silicon can be at least one of monocrystalline silicon, polycrystalline silicon, amorphous silicon, or microcrystalline silicon. In practical applications, the substrate material can also be a compound semiconductor material. Common compound semiconductor materials include, but are not limited to, silicon germanide, silicon carbide, gallium arsenide, indium gallium dihydrogen phosphate, perovskite, cadmium telluride, and copper indium selenide.

[0083] In the two embodiments described above, reference is made to... Figure 4 or Figure 5 The conductive portion 130 and the passivation layer 102 may be doped with the same type of doping element, and along the direction from the bottom cell 100 to the perovskite cell 101, the passivation layer 102 may include at least a stacked layer A (not shown in the figure) and a (A+1) layer (not shown in the figure), the doping concentration of the doping element in the layer A is lower than the doping concentration of the doping element in the (A+1) layer, where A is a positive integer greater than or equal to 1.

[0084] It is worth noting that increasing the doping concentration helps improve the conductivity of the passivation layer 102. In other words, as the carriers generated by the bottom cell 100 move along the transport path of the passivation layer 102, the transport resistance caused by the passivation layer 102 to the carriers is reduced layer by layer, which helps to reduce the series resistance between the bottom cell 100 and the perovskite cell 101.

[0085] It should be noted that when A is large enough, it can be considered that the doping concentration of the doped element in the passivation layer 102 gradually changes and gradually increases along the direction from the bottom cell 100 to the perovskite cell 101.

[0086] Furthermore, the doping concentration of the dopant element in the passivation layer 102 refers to the average doping concentration of activated and unactivated dopant elements contained in the passivation layer 102. In practical applications, 3 to 5 sampling points can be selected in the passivation layer 102, and the doping concentration of the dopant element at each sampling point can be measured using secondary ion mass spectrometry or transmission electron microscopy, and the average value can be calculated. When the passivation layer 102 includes layer A and layer (A+1), 3 to 5 sampling points can be selected in layer A and layer (A+1) respectively, and the average doping concentration of the dopant element at multiple sampling points in layer A can be calculated as the doping concentration of the dopant element in layer A, and the average doping concentration of the dopant element at multiple sampling points in layer (A+1) can be calculated as the doping concentration of the dopant element in layer (A+1).

[0087] In the two embodiments described above, reference is made to... Figure 4 or Figure 5 Along the direction from the bottom cell 100 to the perovskite cell 101, the doped conductive portion 130 may include at least a stacked portion B (not shown in the figure) and a (B+1) portion (not shown in the figure), wherein the doping concentration of the doping element in the portion B is lower than the doping concentration of the doping element in the (B+1) portion, and B is a positive integer greater than or equal to 1.

[0088] It is worth noting that increasing the doping concentration also helps to improve the conductivity of the doped conductive portion 130. In other words, the transport resistance of the doped conductive portion 130 to the charge carriers generated in the bottom cell 100 is reduced layer by layer in the transport path of the doped conductive portion 130, thereby helping to reduce the series resistance between the bottom cell 100 and the perovskite cell 101.

[0089] It should be noted that when B is large enough, it can be considered that the doping concentration of the doped element in the doped conductive part 130 gradually changes and gradually increases along the direction from the bottom cell 100 to the perovskite cell 101.

[0090] Furthermore, the doping concentration of the dopant element in the doped conductive portion 130 refers to the average doping concentration of activated and unactivated dopant elements contained in the doped conductive portion 130. In practical applications, 3 to 5 sampling points can be selected in the doped conductive portion 130, and the doping concentration of the dopant element at each sampling point can be measured using secondary ion mass spectrometry or transmission electron microscopy, and the average value can be calculated. When the doped conductive portion 130 includes a B portion and a (B+1) portion, 3 to 5 sampling points can be selected in the B portion and the (B+1) portion respectively, and the average doping concentration of the dopant element at multiple sampling points in the B portion can be calculated as the doping concentration of the dopant element in the B portion, and the average doping concentration of the dopant element at multiple sampling points in the (B+1) portion can be calculated as the doping concentration of the dopant element in the (B+1) portion.

[0091] In the two embodiments described above, reference is made to... Figure 6 , Figure 6 This is a schematic diagram of a fourth partial cross-sectional structure of a tandem solar cell provided in an embodiment of the present disclosure. The perovskite solar cell 101 may further include a repair layer 141 located on the side of the perovskite layer 121 away from the passivation layer 102. Thus, the repair layer 141 can passivate defects on the surface of the perovskite layer 121 away from the passivation layer 102, thereby reducing the defect state density on the surface of the perovskite layer 121 away from the passivation layer 102. Moreover, with the combined action of the passivation layer 102 and the repair layer 141, double-sided passivation of the perovskite layer 121 can be achieved, thereby improving the carrier collection efficiency of the hole transport layer 111 and the electron transport layer 131. It should be noted that... Figure 6 The example shown is that the passivation layer 102 is located between the hole transport layer 111 and the doped conductive portion 130.

[0092] In some cases, along the first direction X, i.e., the direction from the bottom cell 100 to the perovskite cell 101, the thickness H1 of the repair layer 141 can be 1nm to 5nm, for example, 1nm to 2nm, 2nm to 3nm, 3nm to 4nm, or 4nm to 5nm. Optionally, the thickness H1 of the repair layer 141 can be 1nm, 1.5nm, 2nm, 2.5nm, 3nm, 3.5nm, 4nm, 4.5nm, or 5nm.

[0093] It should be noted that the thickness H1 of the repair layer 141 can be measured by sampling. For example, a partial electron microscope (SEM) image of the area where the repair layer 141 is located can be taken, and 3 to 5 sampling areas can be selected in the repair layer 141. The thickness of each sampling area along the first direction X can be measured, and the average value can be calculated as the thickness H1 of the repair layer 141.

[0094] The following details other designs in tandem cells, and these other designs are applicable to... Figure 4 The stacked battery shown is also suitable for Figure 5 The stacked battery shown.

[0095] In some embodiments, reference Figure 1 The material of the passivation layer 102 may include at least one of aluminum fluoride, lithium fluoride, magnesium fluoride, cesium fluoride, sodium fluoride, potassium fluoride, calcium fluoride, aluminum oxide, silicon oxide, silicon nitride, silicon fluoride, silicon oxyfluoride, silicon oxycarbonate, or aluminum oxynitride.

[0096] In some cases, refer to Figure 1Along the first direction X, the thickness H2 of the passivation layer 102 can be 2nm to 8nm, for example, it can be 2nm to 3nm, 3nm to 4nm, 4nm to 5nm, 5nm to 6nm, 6nm to 7nm, or 7nm to 8nm. Optionally, the thickness H2 of the passivation layer 102 can be 2nm, 2.5nm, 3nm, 3.5nm, 4nm, 4.5nm, 5nm, 5.5nm, 6nm, 6.5nm, 7nm, 7.5nm, or 8nm.

[0097] It should be noted that the method for measuring the thickness H2 of the passivation layer 102 is roughly the same as the method for measuring the thickness H1 of the repair layer 141 in the aforementioned embodiment, and will not be repeated here.

[0098] In some embodiments, in conjunction with reference Figure 7 and Figure 8 The perovskite solar cell 101 may further include a second transparent conductive layer 151, the surface of which the second transparent conductive layer 151 away from the bottom cell 100 has a plurality of protrusions 1511.

[0099] It should be noted that, Figure 7 This is a schematic diagram of a fifth partial cross-sectional structure of a stacked battery provided in an embodiment of the present disclosure; Figure 8 This is a partial top view of the structure of the second transparent conductive layer in a stacked battery according to an embodiment of the present disclosure.

[0100] also, Figure 7 The image uses only black dots as an example to illustrate the multiple protrusions 1511 on the surface of the second transparent conductive layer 151 away from the bottom battery 100. In practical applications, the protrusions can be spherical particles or particles with other irregular shapes. In other words, the surface morphology of the protrusions has a certain degree of randomness. The cross-sectional shape of the protrusion along any cross-section can be approximately circular, elliptical, C-sided, or an irregular shape, where C is a positive integer greater than or equal to 3. Figure 8 The area outlined in black indicates the second transparent conductive layer 151 away from the bottom battery 100 (reference). Figure 7 The surface of the ) has multiple protrusions 1511.

[0101] It is worth noting that the surface of the second transparent conductive layer 151 away from the bottom cell 100 can generally be considered as the light-facing surface. The surface of the second transparent conductive layer 151 away from the bottom cell 100 is designed to have multiple protrusions 1511. On the one hand, the protrusions 1511 help to enhance the light-trapping effect of the second transparent conductive layer 151, allowing more light to pass through the second transparent conductive layer 151 and illuminate the interior of the perovskite cell 101 for absorption and utilization, thereby generating more charge carriers. On the other hand, the protrusions 1511 help to increase the contact area between the subsequent electrode and the second transparent conductive layer 151, reducing the contact resistance between them, thus improving the charge carrier collection efficiency of the electrode. Thus, the combined effect of these factors helps to further improve the power conversion efficiency of the tandem cell.

[0102] In addition, the protrusion 1511 helps to improve the adhesion between the subsequent electrode and the second transparent conductive layer 151, thereby improving the connection strength between the two and improving the structural stability of the stacked battery.

[0103] The specific location of the second transparent conductive layer 151 in the perovskite solar cell 101 will be described in detail below.

[0104] In some cases, refer to Figure 7 The perovskite solar cell 101 may include a stacked hole transport layer 111, a perovskite layer 121, and an electron transport layer 131; the bottom cell 100 may include a stacked substrate 120 and a doped conductive portion 130; wherein, a passivation layer 102 is located between the hole transport layer 111 and the doped conductive portion 130. Based on this, a second transparent conductive layer 151 may be located on the side of the electron transport layer 131 away from the perovskite layer 121, and the surface of the second transparent conductive layer 151 away from the electron transport layer 131 has a plurality of protrusions 1511.

[0105] In other cases, refer to Figure 5 The perovskite solar cell 101 may include a stacked electron transport layer 131, a perovskite layer 121, and a hole transport layer 111; the bottom cell 100 may include a stacked substrate 120 and a doped conductive portion 130; wherein, a passivation layer 102 is located between the electron transport layer 131 and the doped conductive portion 130. Based on this, a second transparent conductive layer ( Figure 5 (Not shown) can be located on the side of electron transport layer 131 away from perovskite layer 121, that is, between electron transport layer 131 and connection layer 123.

[0106] The protrusions 1511 in the second transparent conductive layer 151 will be described in detail below.

[0107] In some cases, refer to Figure 7, the size D of the protrusion 1511 may be 1 μm ~ 4 μm, for example, it may be 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2 μm, 2.1 μm, 2.2 μm, 2 .3μm, 2.4μm, 2.5μm, 2.6μm, 2.7μm, 2.8μm, 2.9μm, 3μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, 3.5μm, 3.6μm, 3.7μm, 3.8μm, 3.9μm or 4μm, etc.

[0108] It is worth noting that, on the one hand, considering that the wavelength range of light absorbed and utilized by the perovskite layer 121 in the perovskite solar cell 101 is generally 300nm~1000nm, designing the size of the protrusion 1511 to be at the micrometer level rather than the nanometer level is beneficial to improving the matching degree between the size of the protrusion 1511 and the wavelength of light absorbed and utilized by the perovskite layer 121, thereby improving the scattering effect of the protrusion 1511 on the light absorbed and utilized by the perovskite layer 121, and thus improving the light-trapping effect of the second transparent conductive layer 151. It is also worth noting that if the size of the protrusion is less than 100nm, it can be considered that the size of the protrusion is at the nanometer level, and the gain of nanometer-level protrusions on the light-trapping effect of the perovskite layer is not significant or even non-existent.

[0109] On the other hand, designing the size of the protrusion 1511 to be at the micrometer level rather than the nanometer level is beneficial to reducing the specific surface area of ​​the second transparent conductive layer 151, that is, reducing the ratio of the surface area to the volume of the second transparent conductive layer 151. This can reduce the parasitic absorption of light, especially short-wavelength light, by the second transparent conductive layer 151, thereby avoiding the temperature rise of the second transparent conductive layer 151.

[0110] On the other hand, compared with nanoscale protrusions, micron-scale protrusions 1511 are less prone to agglomeration, which helps to improve the uniformity of the distribution of protrusions 1511 in the second transparent conductive layer 151 and improve the structural stability of the second transparent conductive layer 151, thereby helping to make each region in the second transparent conductive layer 151 have a basically consistent light trapping effect.

[0111] In other cases, the size of the protrusions can also be 4μm to 10μm. It is worth noting that if the protrusion size is greater than 10μm, the number of protrusions that can be placed per unit area in the transparent conductive layer will be significantly reduced, which is detrimental to improving the light-trapping effect of the transparent conductive layer. Therefore, designing the protrusion size to be 1μm to 10μm helps to ensure a moderate number of protrusions that can be placed per unit area in the transparent conductive layer, thus guaranteeing a better light-trapping effect. Among these, designing the protrusion size to be 1μm to 4μm results in an even better light-trapping effect for the transparent conductive layer.

[0112] Furthermore, the size of protrusion 1511 will vary depending on the different processes used to prepare it. The preparation process of protrusion 1511 will be described similarly later.

[0113] It should be noted that the dimension D of the protrusion 1511 can be any one of the diameter of the protrusion 1511 or the side length or diagonal length of the orthographic projection pattern of the protrusion 1511 on the perovskite layer 121. In practical applications, the orthographic projection pattern of the protrusion on the substrate can also be an irregular polygon. In this case, the side length or diagonal length of the orthographic projection pattern of the protrusion on the substrate is not absolute, but is artificially defined to characterize the size of the protrusion. For example, when the orthographic projection pattern of the protrusion on the substrate is an irregular quadrilateral, the length of the orthographic projection pattern of the protrusion on the substrate can be defined as the side length of the longest side of the irregular quadrilateral, the width of the orthographic projection pattern of the protrusion on the substrate can be defined as the side length of the shortest side of the irregular quadrilateral, and the diagonal length of the orthographic projection pattern of the protrusion on the substrate can be defined as the side length of the longest diagonal of the irregular quadrilateral. It should be understood that the above is only an exemplary illustration, and in practice, it can be flexibly defined according to actual needs.

[0114] In addition, the orthographic projection pattern of the protrusion on the base can be an irregular quadrilateral, or other irregular polygons, circles, or irregular shapes that are approximately circular. In this case, the size of the protrusion is selected from multiple regions of different specific areas within the protrusion. These specific areas can be flexibly defined according to actual needs, and then the average value of the side length, diagonal, or diameter of the multiple regions of different specific areas is calculated.

[0115] In some cases, refer to Figure 7 The distribution density of protrusion 1511 can be 2.5 × 10⁻⁶. 6 pcs / cm 2 ~4.5×10 6 pcs / cm 2 .

[0116] In some cases, refer to Figure 7 The material of the protrusion 1511 can be the same as the material of the second transparent conductive layer 151.

[0117] In some examples, the material of the protrusion 1511 can be integrally formed with the second transparent conductive layer 151, which helps to improve the efficiency of fabricating the protrusion 1511 and the second transparent conductive layer 151 and reduce their fabrication cost.

[0118] In some examples, the material of the protrusion 1511 and the material of the second transparent conductive layer 151 can be at least one of tin-doped indium oxide, tungsten-doped indium oxide, cesium-doped indium oxide, tin oxide, cisium-doped zinc oxide, aluminum-doped zinc oxide, and zinc aluminum oxide.

[0119] In other examples, the material of protrusion 1511 may include at least one of silicon oxide, titanium oxide, zinc oxide, and silver nanoparticles, and the material of the second transparent conductive layer 151 may include at least one of tin-doped indium oxide, tungsten-doped indium oxide, cesium-doped indium oxide, molybdenum-doped indium oxide, cerium-doped indium oxide, indium hydroxide, tin oxide, zirconium-doped zinc oxide, aluminum-doped zinc oxide, and zinc aluminum oxide. In other words, the material of protrusion 1511 is different from the material of the second transparent conductive layer 151.

[0120] In some embodiments, reference Figure 9 The perovskite solar cell 101 may include a first transparent conductive layer 161, a hole transport layer 111, a perovskite layer 121, an electron transport layer 131 and a second transparent conductive layer 151 stacked along a first direction X; the surface of the first transparent conductive layer 161 away from the hole transport layer 111 may have multiple protrusions (not shown in the figure).

[0121] It should be noted that the protrusions on the surface of the first transparent conductive layer 161 are similar to the protrusions 1511 on the surface of the second transparent conductive layer 151, and the material of the first transparent conductive layer 161 is similar to the material of the second transparent conductive layer 151. Therefore, the parts of the first transparent conductive layer 161 and the second transparent conductive layer 151 that are the same or corresponding will not be described again here.

[0122] In some embodiments, reference Figure 1 The bottom battery 100 can be a whole battery or a segmented battery.

[0123] It should be noted that a segmented battery refers to a battery formed by dividing a complete cell into segments. A segmented battery can be 1 / E of a complete cell, where E is a positive integer. In some cases, E is 2, meaning the segmented battery can be half a cell or a two-segment battery; in other cases, E is 3, meaning the segmented battery can be three-segment batteries; and in still other cases, E is 4, meaning the segmented battery can be four-segment batteries.

[0124] In some cases, the bottom cell 100 is a segmented cell; the method of forming a segmented cell may include: cleaning the surface of the entire cell to remove the silicon nitride layer on the surface and expose the doped conductive portion 130 (see reference). Figure 4 Then, a laser cutting process is used to divide the entire cell into at least two cell segments.

[0125] It is worth noting that during the process of forming the sectional solar cells, the doped conductive portion 130 is exposed to air, and the cutting edges of the sectional solar cells are subject to certain laser damage. Therefore, a passivation layer 102 is designed on the surface of the bottom solar cell 100 near the perovskite solar cell 101. This passivation layer 102 is formed on the exposed doped conductive portion 130, which not only provides passivation protection for the exposed doped conductive portion 130 but also repairs the laser damage caused by the laser cutting process, thus passivating the cutting edges of the sectional solar cells. This helps to improve the open-circuit voltage and fill factor of the bottom solar cell 100.

[0126] In other cases, the base cell 100 is a single cell. In the process of using a single cell as the base cell 100, the surface of the single cell is first cleaned to remove the silicon nitride layer and expose the doped conductive portion 130 (see reference). Figure 4 Then, a perovskite solar cell 101 is fabricated on the entire cell. Based on this, a passivation layer 102 is designed on the surface of the bottom cell 100 near the perovskite solar cell 101, that is, a passivation layer 102 is formed on the exposed doped conductive portion 130, which can also passivate and protect the exposed doped conductive portion 130, thereby helping to improve the open circuit voltage and fill factor of the bottom cell 100.

[0127] In some cases, the bottom cell 100 is a segmented cell, and the aspect ratio of the segmented cell can be 1 to 3.5, for example, it can be 1 to 1.5, 1.5 to 2, 2 to 2.5, 2.5 to 3 or 3 to 3.5, etc. Optionally, the aspect ratio of the segmented battery can be 1, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2, 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35, 2.4, 2.45, 2.5, 2.55, 2.6, 2.65, 2.7, 2.75, 2.8, 2.85, 2.9, 2.95, 3, 3.05, 3.1, 3.15, 3.2, 3.25, 3.3, 3.35, 3.4, 3.45, or 3.5, etc.

[0128] In some examples, the length and width of the segmented battery can be 2.5cm to 25cm, for example, 2.5cm to 5cm, 5cm to 15cm, 10cm to 15cm, 15cm to 20cm or 20cm to 25cm. Optionally, the length and width of the segmented battery can be 2.5cm, 3cm, 3.5cm, 4cm, 4.5cm, 5cm, 5.5cm, 6cm, 6.5cm, 7cm, 7.5cm, 8cm, 8.5cm, 9cm, 9.5cm, 10cm, 10.5cm, 11cm, 11.5cm, 12cm, 12.5cm, 13cm, 13.5cm, 14cm, 14.5cm, 15cm, 15.5cm, 16cm, 16.5cm, 17cm, 17.5cm, 18cm, 18.5cm, 19.5cm, 20cm, 20.5cm, 21cm, 21.5cm, 22cm, 22.5cm, 23cm, 23.5cm, 24cm, 24.5cm, or 25cm, etc.

[0129] In some cases, the segmented battery can be a square with a length and width of 2.5cm, 8cm, or 18.2cm.

[0130] In some embodiments, reference Figure 9 , Figure 9 This is a schematic diagram of a sixth partial cross-sectional structure of a stacked battery provided in an embodiment of the present disclosure. The perovskite battery 101 may include a first transparent conductive layer 161, a hole transport layer 111, a perovskite layer 121 and an electron transport layer 131 stacked along a first direction X.

[0131] The first transparent conductive layer 161, hole transport layer 111, perovskite layer 121 and electron transport layer 131 will be described in detail below.

[0132] In some cases, refer to Figure 9 Along the first direction X, the thickness H3 of the hole transport layer 111 can be less than or equal to the thickness H4 of the first transparent conductive layer 161.

[0133] It should be noted that the measurement methods for the thickness H3 of the hole transport layer 111 and the thickness H4 of the first transparent conductive layer 161 are roughly the same as the measurement methods for the thickness H1 of the repair layer 141 in the aforementioned embodiments, and will not be repeated here.

[0134] In some examples, the hole transport layer 111 can be a hybrid SAM layer, that is, the hole transport layer 111 includes at least two types of SAM (Self-Assembled Monolayer).

[0135] In some examples, the material of the first transparent conductive layer 161 can be indium tin oxide.

[0136] It is worth noting that the hole transport layer 111 is mainly used to modify the interface of the perovskite layer 121, reduce the recombination risk of charge carriers, and facilitate the rapid extraction of holes, thereby promoting the longitudinal transport of charge carriers. The first transparent conductive layer 161 needs to balance conductivity and light transmittance to promote the lateral transport of charge carriers. Based on this, the thickness H3 of the hole transport layer 111 is designed to be less than or equal to the thickness of the first transparent conductive layer 161. This is beneficial for maintaining a relatively thin hole transport layer 111 to avoid increasing the series resistance, and for ensuring that the thickness H4 of the first transparent conductive layer 161 has a suitable thickness to ensure good conductivity of the first transparent conductive layer 161, while avoiding a decrease in light transmittance due to an excessively large thickness H4 of the first transparent conductive layer 161.

[0137] In some examples, the thickness H3 of the hole transport layer 111 along the first direction X can be 1nm to 5nm, for example, it can be 1nm to 2nm, 2nm to 3nm, 3nm to 4nm, or 4nm to 5nm, etc. Optionally, the thickness H3 of the hole transport layer 111 can be 1nm, 1.5nm, 2nm, 2.5nm, 3nm, 3.5nm, 4nm, 4.5nm, or 5nm, etc.

[0138] In some examples, the thickness H4 of the first transparent conductive layer 161 along the first direction X can be 5nm to 20nm, for example, it can be 5nm to 10nm, 10nm to 15nm, or 15nm to 20nm. Optionally, the thickness H4 of the first transparent conductive layer 161 can be 5nm, 6nm, 7nm, 8nm, 9nm, 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, or 20nm.

[0139] In some cases, refer to Figure 4Along the first direction X, the thickness H7 of the perovskite layer 121 can be 600nm~800nm, for example, 600nm~650nm, 650nm~700nm, 700nm~750nm, or 750nm~800nm. Optionally, the thickness H7 of the perovskite layer 121 can be 600nm, 610nm, 620nm, 630nm, 640nm, 650nm, 660nm, 670nm, 680nm, 690nm, 700nm, 710nm, 720nm, 730nm, 740nm, 750nm, 760nm, 770nm, 780nm, or 800nm. It should be noted that the measurement method of the thickness H7 of the perovskite layer 121 is roughly the same as the measurement method of the thickness H1 of the repair layer 141 in the aforementioned embodiment, and will not be repeated here.

[0140] In some cases, refer to Figure 9 The electron transport layer 131 may include an interface layer 1311 and a conductive layer 1312 located on the side of the interface layer 1311 away from the perovskite layer 121. Along the first direction X, the thickness H5 of the interface layer 1311 may be less than or equal to the thickness H6 of the conductive layer 1312. In other cases, refer to... Figure 4 or Figure 5 The electron transport layer 131 can also be a single-film structure. It should be noted that the measurement methods for the thickness H5 of the interface layer 1311 and the thickness H6 of the conductive layer 1312 are roughly the same as the measurement methods for the thickness H1 of the repair layer 141 in the aforementioned embodiments, and will not be repeated here.

[0141] In some examples, the material of the interface layer 1311 can be a fullerene.

[0142] In some examples, the material of the conductive layer 1312 can be tin dioxide.

[0143] It is worth noting that the interface layer 1311 is mainly used to modify the interface of the perovskite layer 121, reduce the recombination risk of charge carriers, and facilitate the rapid extraction of electrons, thereby promoting the longitudinal transport of charge carriers. The conductive layer 1312 needs to balance conductivity and light transmittance to promote the lateral transport of charge carriers and effectively block holes and protect the electron transport layer 131. Based on this, the thickness H5 of the interface layer 1311 is designed to be less than or equal to the thickness H6 of the conductive layer 1312. This is beneficial for maintaining a relatively thin interface layer 1311 to avoid increasing the series resistance, and for ensuring that the thickness H6 of the conductive layer 1312 has a suitable thickness to ensure good conductivity of the first transparent conductive layer 161, while avoiding damage to the interface layer 1311 caused by subsequent electrode fabrication processes, such as vapor deposition.

[0144] In some examples, the thickness H5 of the interface layer 1311 along the first direction X can be 10nm to 20nm, for example, 10nm to 15nm or 15nm to 20nm. Optionally, the thickness H5 of the interface layer 1311 can be 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm or 20nm, etc.

[0145] In some examples, the thickness H6 of the conductive layer 1312 along the first direction X can be 10nm to 30nm, for example, it can be 10nm to 15nm, 15nm to 20nm, 20nm to 25nm, or 25nm to 30nm. Optionally, the thickness H6 of the conductive layer 1312 can be 10nm, 11nm, 12nm, 13nm, 14nm, 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, 24nm, 25nm, 26nm, 27nm, 28nm, 29nm, or 30nm.

[0146] In some embodiments, reference Figure 9 The stacked cell may further include: a first electrode 114 located on the side of the second transparent conductive layer 151 away from the bottom cell 100; and a second electrode 124 located on the side of the bottom cell 100 away from the perovskite cell 101.

[0147] In summary, firstly, the passivation layer 102 helps reduce the risk of recombination of charge carriers generated in the bottom cell 100 at the surface of the bottom cell 100 near the perovskite cell 101, and also reduces the risk of recombination of charge carriers generated in the perovskite cell 101 at the surface of the perovskite cell 101 near the bottom cell 100, thereby improving carrier lifetime and reducing the series resistance between the bottom cell 100 and the perovskite cell 101. Furthermore, the recessed region 112 on the surface of the passivation layer 102 near the perovskite cell 101 helps improve the light-trapping effect of the passivation layer 102, allowing more light to pass through the passivation layer 102 and be absorbed and utilized by the bottom cell 100, thus improving the photoelectric conversion efficiency of the bottom cell 100. Furthermore, the conductive portion 103 fills the recessed area 112 to a certain extent, improving the flatness of the connecting layer 123, which is formed by the passivation layer 102 and the conductive portion 103, near the surface of the perovskite solar cell 101. This improves the film quality of the perovskite solar cell 101 located on the connecting layer 123, without affecting the light-trapping efficiency of the passivation layer 102. The conductive portion 103 further enhances the conductivity of the connecting layer 123, thereby further reducing the series resistance between the base cell 100 and the perovskite solar cell 101. In addition, the conductive portion 103 can reflect some light, allowing it to propagate back into the perovskite solar cell 101, thus improving the light absorption and utilization rate of the tandem solar cell. Therefore, it is beneficial to improve the power conversion efficiency of the tandem solar cell from multiple aspects.

[0148] Another embodiment of this disclosure provides a method for manufacturing a stacked battery, used to form the stacked battery provided in the foregoing embodiments. The manufacturing method of the stacked battery provided in another embodiment of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that parts that are the same as or corresponding to those in the foregoing embodiments can be referred to the corresponding descriptions in the foregoing embodiments, and will not be repeated hereafter.

[0149] Reference Figures 10 to 12 , Figure 10 This is a process flow diagram of a method for manufacturing a stacked battery according to another embodiment of this disclosure. Figure 11 This is a partial cross-sectional view of the structure after the passivation layer is formed in a method for manufacturing a stacked battery according to another embodiment of this disclosure. Figure 12 This is a partial cross-sectional view of the structure after the conductive portion is formed in a method for manufacturing a stacked battery according to another embodiment of this disclosure; the method for manufacturing a stacked battery includes at least the following steps: S1: Provides a 100mAh battery.

[0150] S2: A passivation layer 102 is formed on one surface of the bottom battery 100, and the surface of the passivation layer 102 away from the bottom battery 100 has at least one recessed region 112 that is recessed into the bottom battery 100.

[0151] S3: A conductive portion 103 is formed on the recessed region 112, and the passivation layer 102 and the conductive portion 103 together constitute the connecting layer 123.

[0152] S4: A perovskite cell 101 is formed on the side of the connecting layer 123 away from the bottom cell 100.

[0153] Thus, the step of forming the connecting layer 123 is interspersed between the steps of forming the base cell 100 and forming the perovskite cell 101. The passivation layer 102 is formed on the surface of the base cell 100 where the perovskite cell 101 will be subsequently stacked. On the one hand, the passivation layer 102 can passivate the surface of the base cell 100 near the perovskite cell 101. On the other hand, the recessed region 112 of the formed passivation layer 102 near the surface of the perovskite cell 101 is beneficial to improving the light trapping effect of the passivation layer 102. Furthermore, the conductive portion 103 is formed on the recessed region 112, which improves the flatness of the connecting layer 123 formed by the passivation layer 102 and the conductive portion 103 near the surface of the perovskite cell 101. This improves the film quality of the perovskite cell 101 formed on the side of the connecting layer 123 away from the base cell 100, without affecting the light trapping efficiency of the passivation layer 102, and the conductivity of the connecting layer 123 can be further improved by means of the conductive portion 103. Furthermore, the conductive portion 103 can reflect some of the light, allowing it to propagate back into the perovskite solar cell 101, thereby improving the light absorption and utilization rate of the tandem solar cell. This contributes to improving the power conversion efficiency of the tandem solar cell from multiple perspectives.

[0154] It should be noted that in the manufacturing method of the stacked battery provided in another embodiment of this disclosure, the manufacturing method of the conductive part 103 is not limited. For example, a deposition process can be used to form a plurality of conductive parts 103 that are scattered on the passivation layer 102, as long as the conductive parts 103 have a certain filling effect on the recessed area 112.

[0155] In some embodiments, reference Figure 11 The surface of the bottom battery 100 near the passivation layer 102 is presented as a first texture structure 110; the method of forming the passivation layer 102 may include: forming the passivation layer 102 on the first texture structure 110 by a deposition process, so that the surface of the passivation layer 102 away from the bottom battery 100 is presented as a second texture structure 122, and the second texture structure 122 has a recessed area 112.

[0156] Thus, when a passivation layer 102 is formed on the first texture structure 110 using a deposition process, the first texture structure 110 serves as the deposition surface, which helps to make the surface of the passivation layer 102 present a morphology similar to that of the first texture structure 110. Even if the surface of the passivation layer 102 far from the bottom cell 100 presents a second texture structure 122, the absorption and utilization rate of light by the bottom cell 100 can be improved.

[0157] In some cases, the deposition process for forming the passivation layer 102 can be an ALD (Atomic Layer Deposition) process, which causes the passivation layer 102 to conformally cover the first texture structure 110.

[0158] In some examples, the step of forming the passivation layer 102 using the ALD process may include: placing the bottom cell 100 in a reaction chamber and alternately introducing an aluminum source and a fluorine source into the reaction chamber to form a passivation layer 102 comprising aluminum fluoride.

[0159] In one example, the aluminum source can be trimethylaluminum and the fluorine source can be nitrogen trifluoride. The raw materials for forming the passivation layer 102 are inexpensive and the manufacturing process is simple, making it suitable for industrial production. Moreover, the passivation layer 102, which includes aluminum fluoride, has good structural stability and can control the degradation of the tandem battery to within 2% even after being stored outdoors for more than 1000 hours.

[0160] The manufacturing process of perovskite solar cells will be explained in detail below.

[0161] In some embodiments, in conjunction with reference Figure 12 and Figure 4 The method of forming the perovskite solar cell 101 may include: using a spin coating process to sequentially form a hole transport layer 111 and a perovskite layer 121 on at least the side of the connecting layer 123 away from the bottom cell 100.

[0162] It is worth noting that the spin coating process requires a certain degree of flatness of the surface to be spin-coated. The higher the flatness of the surface, the better the quality of the film layer spin-coated on that surface, such as better thickness uniformity. Based on this, while the passivation layer 102 has a recessed region 112 on its surface to improve its light-trapping efficiency, a conductive portion 103 is formed on the recessed region 112. This not only does not affect the light-trapping efficiency of the passivation layer 102, but also improves the flatness of the connecting layer 123, which is formed by the passivation layer 102 and the conductive portion 103, near the surface of the perovskite solar cell 101. This is beneficial for forming a perovskite solar cell 101 with better film quality, and further helps to reduce interface defects of the perovskite solar cell 101 near the surface of the bottom cell 100.

[0163] In some cases, refer to Figure 9After forming the interconnect layer 123 and before forming the hole transport layer 111, the method for forming the perovskite solar cell 101 may further include: forming a first transparent conductive layer 161 on the side of the interconnect layer 123 away from the bottom cell 100; and forming the hole transport layer 111 on the side of the first transparent conductive layer 161 away from the interconnect layer 123. It should be noted that the manufacturing method of the first transparent conductive layer 161 is not limited and can be selected according to actual needs; for example, the first transparent conductive layer 161 can be formed using a magnetron sputtering process.

[0164] In some examples, the method of forming hole transport layer 111 may include: weighing 1 mg of a carbazole-based hole transport material, such as 2PACZ ([2-(9H-Carbazol-9-yl)ethyl]phosphonic acid), dissolving it completely in 1 mL of ethanol solution, adding a magnetic stir bar, and stirring overnight on a stirrer to dissolve the carbazole-based hole transport material in the ethanol solution to obtain a first precursor solution; subsequently weighing 1 mg of another hole transport material, such as Py3 ([2-(pyren-1-yl)ethyl]phosphonic acid), [2-(pyrene-1-yl)ethyl]phosphoric acid) is dissolved in an ethanol solution and stirred until fully dissolved to obtain a second precursor solution. The two precursor solutions are then mixed in a ratio of 1:2 or 1:3 and shaken until fully mixed. An appropriate amount of solution is then uniformly dropped onto the surface of the bottom battery 100 and spin-coated at a speed of about 4000 rpm to 5000 rpm for about 20 to 30 seconds. The mixture is then annealed at a temperature of about 100°C to 140°C for about 10 minutes and then cooled to room temperature to form a hole transport layer 111.

[0165] In some cases, refer to Figure 9 The method for forming the perovskite layer 121 may include: spreading approximately 50 microliters of perovskite solution across the side of the hole transport layer 111 away from the connecting layer 123, spin-coating at approximately 3000 rpm to 5000 rpm for approximately 20 to 30 seconds, and then annealing at approximately 90°C to 100°C for approximately 10 minutes to form the perovskite layer 121. It should be noted that the preparation of the perovskite solution can be adjusted according to actual needs.

[0166] In some cases, refer to Figure 9 The method of forming the perovskite solar cell 101 may further include: using a spin coating process to form a repair layer 141 on the side of the perovskite layer 121 away from the hole transport layer 111.

[0167] It is worth noting that by forming a conductive portion 103 on the recessed region 112, and improving the flatness of the connection layer 123, which is composed of the passivation layer 102 and the conductive portion 103, near the surface of the perovskite solar cell 101, it is not only beneficial to form a perovskite solar cell 101 with better film quality based on the flat surface of the connection layer 123, but also further flattens the surface of the perovskite layer 121, thereby improving the perovskite solar cell 101 with better film quality based on the flat surface of the perovskite layer 121. This enhances the passivation effect of the repair layer 141 on the side of the perovskite layer 121 away from the hole transport layer 111, thereby reducing interface defects on the surface of the perovskite layer 121 away from the bottom cell 100.

[0168] In some examples, the method of forming the repair layer 141 may include: dissolving EDAI2 (Ethylenediammonium Diiodide) in IPA (Isopropyl Alcohol) to prepare a repair solution with a concentration of about 0.5 mg / ml, spreading about 100 μL of the repair solution on the side of the perovskite layer 121 away from the hole transport layer 111, spin-coating at about 5000 rpm for about 30 s, and then annealing at a temperature of about 100°C for about 10 minutes to form the repair layer 141.

[0169] In some cases, refer to Figure 9 The method of forming a perovskite solar cell 101 may further include: using a deposition process to form an electron transport layer 131 on the side of the perovskite layer 121 away from the hole transport layer 111.

[0170] In some examples, reference Figure 9 The method of forming electron transport layer 131 may include: forming an interface layer 1311 on the side of perovskite layer 121 away from hole transport layer 111; and forming a conductive layer 1312 on the side of interface layer 1311 away from perovskite layer 121.

[0171] In some examples, the method of forming the interface layer 1311 may include: depositing a fullerene film on the surface of the perovskite layer 121 away from the hole transport layer 111 using a vapor deposition machine to form the interface layer 1311.

[0172] In some examples, the method of forming the conductive layer 1312 may include: depositing a thin film of tin dioxide using an ALD process to form the conductive layer 1312.

[0173] In other embodiments, in conjunction with reference to Figure 12 and Figure 5The method for forming the perovskite solar cell 101 may include: sequentially forming an electron transport layer 131, a perovskite layer 121, and a hole transport layer 111 on at least the side of the connecting layer 123 away from the bottom cell 100. It should be noted that the method for forming the electron transport layer 131, the perovskite layer 121, and the hole transport layer 111 is largely the same as in the aforementioned embodiments, and will not be repeated here.

[0174] In some embodiments, reference Figure 9 The method of forming a perovskite solar cell 101 may further include: forming a second transparent conductive layer 151.

[0175] In some cases, refer to Figure 9 Before forming the second transparent conductive layer 151, a hole transport layer 111, a perovskite layer 121 and an electron transport layer 131 have been formed in the perovskite solar cell 101. The step of forming the second transparent conductive layer 151 includes forming the second transparent conductive layer 151 on the side of the electron transport layer 131 away from the perovskite layer 121.

[0176] In other cases, refer to Figure 5 Before forming the stacked electron transport layer 131, perovskite layer 121, and hole transport layer 111 in the perovskite solar cell 101, a second transparent conductive layer is first formed on the side of the connecting layer 123 away from the bottom cell 100. Figure 5 (Not shown in the image).

[0177] In both of the above scenarios, the second transparent conductive layer 151 can be deposited using magnetron sputtering.

[0178] In some cases, refer to Figure 7 The method of forming a perovskite solar cell 101 may further include forming a plurality of protrusions 1511 on the surface of the second transparent conductive layer 151 away from the bottom cell 100.

[0179] The method for forming the second transparent conductive layer 151 and the protrusion 1511 is described in detail below.

[0180] In some examples, the second transparent conductive layer 151 is laser-processed to form a plurality of protrusions 1511 on the surface of the second transparent conductive layer 151 away from the bottom battery 100. Laser scanning technology can be used to laser-process the second transparent conductive layer 151.

[0181] In one example, the wavelength of the laser used in the laser processing can be 355nm~532nm, for example, 355nm~400nm, 400nm~450nm, 450nm~500nm, or 500nm~532nm. Optionally, the wavelength of the laser used in the laser processing can be 355nm, 360nm, 370nm, 380nm, 390nm, 400nm, 410nm, 420nm, 430nm, 440nm, 450nm, 460nm, 470nm, 480nm, 490nm, 500nm, 510nm, 520nm, 530nm, or 532nm, etc.

[0182] It is worth noting that if the wavelength of the laser used in the laser processing is less than 355nm, the laser's penetration is weak, which is not conducive to forming a suitable number of protrusions 1511; if the wavelength of the laser used in the laser processing is greater than 532nm, the laser's penetration is strong, which can easily cause laser damage to the film layer (hole transport layer 111 or electron transport layer 131) located below the second transparent conductive layer 151. Therefore, designing the laser used in the laser processing to have a wavelength of 355nm~532nm is beneficial for forming a suitable number of protrusions 1511 in the second transparent conductive layer 151 and for avoiding laser damage to the film layer located below the second transparent conductive layer 151.

[0183] In other examples, the surface of the second transparent conductive layer 151 away from the bottom battery 100 is etched to form a plurality of protrusions 1511 on the surface of the second transparent conductive layer 151 away from the bottom battery 100. The etching step may include: spraying an etching solution onto the surface of the second transparent conductive layer 151 away from the bottom battery 100, and using the etching solution to perform localized etching on the surface of the second transparent conductive layer 151 away from the bottom battery 100, thereby forming the protrusions 1511.

[0184] In one example, the etching solution may be an acidic solution comprising hydrogen chloride and / or ammonium fluoride, wherein the concentration of hydrogen chloride or ammonium fluoride in the etching solution may be 1% to 10%, for example, 1% to 5% or 5% to 10%. Optionally, the concentration of hydrogen chloride or ammonium fluoride in the etching solution may be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%, etc.

[0185] In one example, the etching temperature for etching the surface of the second transparent conductive layer 151 away from the bottom battery 100 can be 25°C to 150°C, for example, 25°C to 50°C, 50°C to 75°C, 75°C to 100°C, 100°C to 125°C, 125°C, or 150°C. Optionally, the etching temperature for etching the surface of the second transparent conductive layer 151 away from the bottom battery 100 can be 25°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, or 150°C, etc.

[0186] In one example, the etching time for etching the surface of the second transparent conductive layer 151 away from the bottom battery 100 can be 30s to 180s, for example, 30s to 55s, 55s to 105s, 105s to 155s, or 155s to 180s. The etching time for etching the surface of the second transparent conductive layer 151 away from the bottom battery 100 can be 30s, 40s, 50s, 60s, 70s, 80s, 90s, 100s, 110s, 120s, 130s, 140s, 150s, 160s, 170s, or 180s, etc.

[0187] In some other examples, the step of forming the second transparent conductive layer 151 includes: forming an initial transparent conductive layer (not shown in the figure); forming a protrusion 1511 on the surface of the initial transparent conductive layer away from the base cell 100; wherein the protrusion 1511 is located on the surface of the initial transparent conductive layer away from the substrate, or partially embedded in the initial transparent conductive layer, then the protrusion 1511 and the initial transparent conductive layer together constitute the second transparent conductive layer 151.

[0188] It is worth noting that protrusions 1511 can be formed on the surface of the initial transparent conductive layer away from the substrate 120 using a coating or deposition process. The coating process applies pressure to the initial transparent conductive layer, which may cause some areas of the protrusions 1511 to embed into the initial transparent conductive layer.

[0189] In some embodiments, reference Figure 9 The method of forming a tandem battery may further include: forming a first electrode 114 on the side of the second transparent conductive layer 151 away from the bottom battery 100, as a lead-out terminal of the tandem battery. It should be noted that in the provided bottom battery 100, a second electrode 124 has been formed on the side of the bottom battery 100 away from the perovskite battery 101, as another lead-out terminal of the tandem battery.

[0190] In some cases, the method of forming the first electrode 114 may include: using a vapor deposition process to form silver on the side of the second transparent conductive layer 151 away from the bottom cell 100. It should be noted that the manufacturing process of the second electrode 124 may employ a vapor deposition process, or other processes used in the actual production of the bottom cell 100, such as screen printing followed by sintering.

[0191] Another embodiment of this disclosure provides a photovoltaic module, which includes multiple stacked cells as provided in the foregoing embodiments, or multiple stacked cells formed by the manufacturing method of the stacked cells provided in the foregoing embodiments. The photovoltaic module is used to convert received light energy into electrical energy. It should be noted that the parts that are the same as or corresponding to those in the foregoing embodiments can be referred to the corresponding descriptions in the foregoing embodiments, and will not be repeated below.

[0192] Reference Figure 13 and Figure 14 The photovoltaic module includes: a battery string, which is formed by connecting multiple stacked batteries 40 provided in the foregoing embodiments, or by connecting multiple stacked batteries 40 formed by the manufacturing method of the stacked batteries provided in the foregoing embodiments; an encapsulating film 41 for covering the surface of the battery string; and a cover plate 42 for covering the surface of the encapsulating film 41 facing away from the battery string.

[0193] in, Figure 13 A partial three-dimensional schematic diagram of a cell string in a photovoltaic module provided in yet another embodiment of this disclosure; Figure 14 This is a partial cross-sectional schematic diagram of a photovoltaic module provided in yet another embodiment of the present disclosure.

[0194] In some cases, multiple tandem cells 40 can be electrically connected via solder strips 43. It is worth noting that electrical connection actually means that both are made of conductive materials and are directly connected or connected via other conductive materials. Therefore, when the tandem cells 40 are generating electricity, there is an electrical connection between them.

[0195] It should be noted that, Figure 13 and Figure 14 This illustration only shows one positional relationship between the stacked cells 40, where each stacked cell 40 has electrodes of the same polarity arranged in the same direction, or in other words, the first electrode of each stacked cell 40 is arranged facing the same side, so that the solder ribbon 43 connects different sides of two adjacent stacked cells 40 respectively. In other embodiments, the stacked cells can also be arranged with electrodes of different polarities facing the same side, that is, the first electrode of one of two adjacent stacked cells and the second electrode of the other face the same side, and the electrodes of the multiple adjacent stacked cells are arranged in the order of first electrode, second electrode, first electrode, and so on, and the solder ribbon connects two adjacent stacked cells on the same side.

[0196] In some embodiments, no gaps are provided between the stacked cells, that is, the stacked cells overlap each other.

[0197] In some embodiments, multiple battery strings are electrically connected in series and / or in parallel.

[0198] In some embodiments, the encapsulating film 41 includes a first encapsulating layer and a second encapsulating layer. The first encapsulating layer covers one of the front or back sides of the stacked battery 40, and the second encapsulating layer covers the other of the front or back sides of the stacked battery 40. Specifically, at least one of the first encapsulating layer or the second encapsulating layer may be an organic encapsulating film such as polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer (EVA), polyolefin thermoplastic elastomer (POE), or polyethylene glycol terephthalate (PET). Alternatively, at least one of the first encapsulating layer or the second encapsulating layer may also be an EP film, an EPE film, or a PVP film. Among them, EP film refers to a co-extruded film composed of stacked EVA film and POE film; EPE film refers to a co-extruded film formed by sequentially stacking EVA film, POE film, and EVA film; and PVP film refers to a co-extruded film formed by stacking POE film, EVA film, and POE film. Co-extruded films can be prepared by sequentially extruding one or more raw materials onto another pre-made film during the film processing, or by bonding different types of pre-made films together.

[0199] In some cases, the first encapsulation layer and the second encapsulation layer still have a boundary line before lamination. After lamination, the photovoltaic module will no longer have the concept of a first encapsulation layer and a second encapsulation layer. That is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0200] In some embodiments, the cover plate 42 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulating film 41 can be an uneven surface or a textured surface containing multiple raised structures, thereby increasing the utilization rate of incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate being opposite to the first encapsulation layer, and the second cover plate being opposite to the second encapsulation layer.

[0201] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.

Claims

1. A stacked battery, characterized in that, include: Stacked configuration of bottom cells and perovskite cells; A passivation layer is located between the bottom cell and the perovskite cell, and the surface of the passivation layer near the perovskite cell has at least one recessed area that is recessed into the bottom cell; A conductive portion is located in the recessed area, and the passivation layer and the conductive portion together constitute a connection layer, through which the bottom cell and the perovskite cell are electrically connected; Wherein, the width of the recessed region is 500nm~800nm, and / or, the width of the conductive part is 200nm~400nm.

2. The stacked battery according to claim 1, characterized in that, The surface of the bottom cell near the passivation layer has a first texture structure, and the surface of the passivation layer near the perovskite cell has a second texture structure, the second texture structure having the recessed area.

3. The stacked battery according to claim 1, characterized in that, Along the first direction, the depth of the recessed area indented toward the bottom cell is 0.1 μm to 1 μm, and the first direction is the stacking direction of the bottom cell and the perovskite cell; and / or, the area of ​​the conductive part on the surface of the passivation layer near the perovskite cell accounts for 50% to 70%.

4. The stacked battery according to claim 1, characterized in that, The perovskite solar cell includes a stacked hole transport layer, a perovskite layer, and an electron transport layer; the bottom cell includes a stacked substrate and a doped conductive portion. The passivation layer is located between the hole transport layer and the doped conductive portion, and the doped conductive portion is doped with an N-type dopant element.

5. The stacked battery according to claim 1, characterized in that, The perovskite solar cell includes an electron transport layer, a perovskite layer, and a hole transport layer stacked together; the bottom cell includes a substrate and a doped conductive portion stacked together. The passivation layer is located between the electron transport layer and the doped conductive portion, and the doped conductive portion is doped with a P-type dopant.

6. The stacked battery according to claim 4 or 5, characterized in that, The doped conductive portion and the passivation layer are doped with the same type of doping element, and along the direction from the bottom cell to the perovskite cell, the passivation layer includes at least a stacked A layer and a (A+1) layer, the doping concentration of the doping element in the A layer is lower than the doping concentration of the doping element in the (A+1) layer, and A is a positive integer greater than or equal to 1.

7. The stacked battery according to claim 4 or 5, characterized in that, Along the direction from the bottom cell to the perovskite cell, the doped conductive portion includes at least a B portion and a (B+1) portion stacked together, wherein the doping concentration of the doping element in the B portion is lower than the doping concentration of the doping element in the (B+1) portion, and B is a positive integer greater than or equal to 1.

8. The stacked battery according to claim 4 or 5, characterized in that, The perovskite solar cell further includes a repair layer located on the side of the perovskite layer away from the passivation layer.

9. The stacked battery according to any one of claims 1 to 5, characterized in that, The passivation layer material includes at least one of aluminum fluoride, lithium fluoride, magnesium fluoride, cesium fluoride, sodium fluoride, potassium fluoride, calcium fluoride, aluminum oxide, silicon oxide, silicon nitride, silicon fluoride, silicon oxyfluoride, silicon oxycarbonate, or aluminum oxynitride.

10. The stacked battery according to claim 1, characterized in that, The perovskite solar cell includes a hole transport layer, a perovskite layer, and an electron transport layer stacked along a first direction. The electron transport layer includes an interface layer and a conductive layer located on the side of the interface layer away from the perovskite layer. Along the first direction, the thickness of the interface layer is less than or equal to the thickness of the conductive layer.

11. The stacked battery according to claim 1, characterized in that, The perovskite solar cell includes a first transparent conductive layer, a hole transport layer, a perovskite layer, and an electron transport layer stacked along a first direction. Wherein, along the first direction, the thickness of the hole transport layer is less than or equal to the thickness of the first transparent conductive layer.

12. The stacked battery according to claim 1, characterized in that, The perovskite solar cell includes a first transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, and a second transparent conductive layer stacked along a first direction. Wherein, the surface of the first transparent conductive layer away from the hole transport layer has multiple protrusions; and / or, the surface of the second transparent conductive layer away from the electron transport layer has multiple protrusions.

13. A method for manufacturing a stacked battery, characterized in that, include: Provide a base battery; A passivation layer is formed on one surface of the bottom battery, and the passivation layer has at least one recessed area that is recessed into the bottom battery on the surface away from the bottom battery. A conductive portion is formed on the recessed region, and the passivation layer and the conductive portion together constitute a connecting layer; wherein the width of the recessed region is 500nm~800nm, and / or the width of the conductive portion is 200nm~400nm; A perovskite cell is formed on the side of the connecting layer away from the bottom cell.

14. The method for manufacturing a stacked battery according to claim 13, characterized in that, The surface of the bottom battery near the passivation layer exhibits a first texture structure; The method for forming the passivation layer includes: forming the passivation layer on the first textured structure using a deposition process, such that the surface of the passivation layer away from the bottom battery presents a second textured structure, and the second textured structure has the recessed area.

15. The method for manufacturing a stacked battery according to claim 13 or 14, characterized in that, The method for forming the perovskite solar cell includes: using a spin coating process to sequentially form a hole transport layer and a perovskite layer on at least the side of the connecting layer away from the bottom cell.

16. The method for manufacturing a stacked battery according to claim 15, characterized in that, The method for forming the perovskite solar cell further includes: using a spin coating process to form a repair layer on the side of the perovskite layer away from the hole transport layer.

17. The method for manufacturing a stacked battery according to claim 15, characterized in that, The method for forming the perovskite solar cell further includes: using a deposition process to form an electron transport layer on the side of the perovskite layer away from the hole transport layer.

18. The method for manufacturing a stacked battery according to claim 13 or 14, characterized in that, The method of forming the perovskite solar cell includes: sequentially forming an electron transport layer, a perovskite layer, and a hole transport layer on at least one side of the interconnecting layer away from the bottom cell.

19. A photovoltaic module, characterized in that, include: A battery string is formed by connecting multiple stacked batteries as described in any one of claims 1 to 12, or by connecting multiple stacked batteries formed by the manufacturing method of the stacked batteries as described in any one of claims 13 to 18. An encapsulating film is used to cover the surface of the battery string; A cover plate is used to cover the surface of the encapsulating film that faces away from the battery string.

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