Calcium-silicon laminated solar cell, preparation method thereof and photovoltaic module

Abstract

The invention discloses a calcium-silicon laminated solar cell, a preparation method thereof and a photovoltaic module, and relates to the technical field of solar cells. The calcium-silicon laminated solar cell comprises a perovskite cell, wherein the perovskite cell comprises a substrate, a transparent conductive layer, a functional layer and a top electrode which are laminated in sequence; the plurality of sub perovskite cells in the sub region of the perovskite cell are connected in series; and the plurality of sub-regions are connected in parallel through buried conductive wires. According to the technical scheme, a series-parallel connection combined mode is adopted, the problem of poor voltage matching between the perovskite cell and the silicon-based cell can be effectively relieved, balanced and stable current can be conveniently generated, and the photoelectric conversion efficiency of the calcium-silicon laminated solar cell is improved; according to the invention, the parallel connection between the sub-regions is completed through the buried conductor wires, the series connection between the plurality of sub perovskite cells in the sub-regions is not affected, the combination effect between the functional layers is better, and the shading effect and the contact resistance can be effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to calcium silicon stacked solar cells and preparation methods thereof, and photovoltaic modules. Background Art

[0002] Perovskite materials themselves have excellent photoelectric properties, such as high light absorption coefficient, long carrier diffusion length and adjustable band gap, which make perovskite solar cells have high photoelectric conversion efficiency. Compared with traditional silicon-based solar cells, the advantages of perovskite solar cells are that they have high photoelectric conversion efficiency, low production cost and solution processability. Calcium-silicon tandem solar cells differentially absorb sunlight with a wider range of wavelengths by superimposing perovskite cells on silicon-based cells, reducing photon thermal loss and improving the photoelectric conversion efficiency of the cells.

[0003] At present, there is a voltage matching problem between the perovskite cell in the calcium-silicon tandem solar cell and the silicon-based cell underneath, which in turn affects the device stability and photoelectric conversion efficiency of the cell.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a calcium-silicon tandem solar cell and a preparation method and a photovoltaic module that have high device stability, can improve the photoelectric conversion efficiency of the cell, and can effectively alleviate the problem of poor voltage matching between perovskite cells and silicon-based cells.

[0006] To achieve the above purpose, this application adopts the following technical solutions: A calcium-silicon tandem solar cell, comprising a perovskite cell, wherein the perovskite cell comprises a substrate, a transparent conductive layer, a functional layer, and a top electrode stacked in sequence; The perovskite cell is divided into a plurality of sub-regions by a positive electrode connection region and / or a negative electrode connection region; one or more groups of P1 grooves, P2 grooves, and P3 grooves are arranged in sequence in any sub-region along the lateral direction of the perovskite cell, so as to divide the perovskite cell in the sub-region into a plurality of sub-perovskite cells connected in series; A first wire groove is provided in the positive electrode connection area, a second wire groove is provided in the negative electrode connection area, and conductive wires are provided in both the first and second wire grooves; the multiple sub-areas are connected in parallel through the conductive wires in the first wire groove and / or the conductive wires in the second wire groove; the top surface of the conductive wire is on the same horizontal plane as the top surface of the transparent conductive layer; the first wire groove, the second wire groove, and the P1 groove respectively penetrate the transparent conductive layer; the P2 groove penetrates the functional layer; and the P3 groove penetrates the top electrode.

[0007] In some embodiments, one or more first groove groups, P2 grooves, first wire grooves, P2 grooves, and one or more second groove groups are sequentially arranged in the positive electrode connection area along the lateral direction of the perovskite battery; And / or, one or more groups of second groove groups, P1 grooves, second wire grooves, P1 grooves, and one or more groups of first groove groups are sequentially arranged in the negative electrode connection area along the lateral direction of the perovskite battery; a P2 groove is also arranged directly above the second wire groove, and the second wire groove is directly connected to the adjacent P1 groove; The first groove group includes groove P1, groove P2 and groove P3, and groove P2 is located on one side of groove P1; the second groove group includes groove P1, groove P2 and groove P3, and groove P2 is located on the other side of groove P1.

[0008] In some embodiments, the first conductive groove sequentially penetrates the transparent conductive layer and a portion of the substrate, and the depth of the first conductive groove does not exceed one third of the thickness of the substrate; And / or, the second conductive groove sequentially penetrates the transparent conductive layer and a portion of the substrate, and the depth of the second conductive groove does not exceed one third of the thickness of the substrate.

[0009] In some embodiments, the thickness of the conductive line is greater than the thickness of the transparent conductive layer.

[0010] In some embodiments, the material of the conductive wire includes one or more of silver and copper.

[0011] In some implementation methods, the spacing between adjacent P1 grooves is recorded as D1, and the spacing between the first conductive line groove and its adjacent P1 groove is recorded as D2; D1 and D2 satisfy: D1=D2.

[0012] In some embodiments, the spacing between adjacent P1 grooves is 4-15 mm.

[0013] In some of the embodiments, a crystalline silicon cell is also included; the crystalline silicon cell and the perovskite cell are stacked.

[0014] The present application also provides a method for preparing a calcium-silicon tandem solar cell, comprising: preparing a perovskite cell; wherein the method for preparing the perovskite cell comprises: Prepare a transparent conductive layer on a substrate; scratch a P1 groove, a first conductive groove and / or a second conductive groove penetrating the transparent conductive layer on the transparent conductive layer; After providing the P1 groove, the first conductive line groove and / or the second conductive line groove, preparing a conductive line in each conductive line groove; After preparing the conductive wire, a hole transport layer, a perovskite light absorption layer, and an electron transport layer are sequentially prepared on the transparent conductive layer; a P2 groove is carved on the electron transport layer, which sequentially penetrates the electron transport layer, the perovskite light absorption layer, and the hole transport layer; On the electron transport layer where the P2 groove has been carved, a top electrode is prepared; on the top electrode, a P3 groove penetrating the top electrode is carved to obtain a perovskite cell including a plurality of sub-perovskite cells; Wherein, the first conducting groove is arranged in the positive electrode connection area, and the second conducting groove is arranged in the negative electrode connection area; the perovskite battery is divided into a plurality of sub-areas by the positive electrode connection area and / or the negative electrode connection area; any of the plurality of sub-areas is provided with one or more groups of P1 grooves, P2 grooves, and P3 grooves arranged in sequence along the lateral direction of the perovskite battery, so as to divide the perovskite battery in the sub-area into a plurality of sub-perovskite batteries connected in series; the plurality of sub-areas are connected in parallel through the conductive wires in the first conducting groove and / or the conductive wires in the second conducting groove.

[0015] The present application also provides a photovoltaic module, including: The calcium-silicon tandem solar cell as described above; or The calcium-silicon tandem solar cell is prepared by the above-mentioned preparation method.

[0016] In the technical solution of the present application, the perovskite battery is used to connect the positive electrode (high end) and / or the negative electrode (low end) between the sub-regions through the positive electrode connection area and / or the negative electrode connection area to each other, thereby completing the parallel connection between the sub-regions, and the multiple sub-perovskite batteries in the sub-regions are connected in series. The combination of series and parallel connection can effectively alleviate the problem of voltage matching difference between the perovskite battery and the silicon-based battery, and at the same time facilitate the generation of balanced and stable current, improve the stability of the device, and effectively and stably transmit the current generated in the battery to the external circuit, thereby significantly improving the light efficiency of the calcium-silicon laminated solar cell. Electrical conversion efficiency and stability; the parallel connection between sub-regions is completed through buried conductive wires, which does not affect the series connection between multiple sub-perovskite batteries in the sub-region, and the combination effect between the functional layers is better, which can not only ensure that the battery has sufficient mechanical strength, but also effectively reduce the shading effect and contact resistance, thereby reducing energy loss and improving the photoelectric conversion efficiency and stability of calcium-silicon stacked solar cells; when the perovskite battery and the crystalline silicon battery are stacked, they have a stable interconnection structure, and the process route is consistent with the process route of a single-cell perovskite solar cell, without the need for iterative equipment, and the technology is mature and can be mass-produced. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application. Figure 1 This is a schematic structural diagram of the positive electrode connection area of ​​the perovskite battery in the embodiment of the present application when the top electrode is not prepared and the P3 groove is not provided; Figure 2 This is a schematic diagram of the structure of the positive electrode connection area of ​​the perovskite battery in an embodiment of the present application; Figure 3 This is a schematic structural diagram of the negative electrode connection area of ​​the perovskite battery in the embodiment of the present application when the top electrode is not prepared and the P3 groove is not provided; Figure 4 This is a schematic diagram of the structure of the negative electrode connection area of ​​the perovskite battery in the embodiment of the present application; Figure 5 A schematic diagram of the embodiment of the present application in which the positive electrode connection area, the negative electrode connection area, and the positive electrode connection area are sequentially arranged to separate the perovskite battery into four sub-areas, and the four sub-areas are connected in parallel; Figure 6 Schematic diagram of the arrangement of the P1 groove, the P2 groove, and the P3 groove of the perovskite battery in the embodiment of the present application; Figure 6 The wire grooves include a first wire groove and a second wire groove; Figure 7Schematic diagram of the arrangement of the P1 groove, P2 groove, and P3 groove of the perovskite battery in the comparative example of the present application.

[0018] Numbers in the figure: 1, substrate; 2, transparent conductive layer; 3, hole transport layer; 4, perovskite light absorption layer; 5, electron transport layer; 6, top electrode; 7, conductive wire; P11, first wire groove; P12, second wire groove. DETAILED DESCRIPTION

[0019] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0020] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not mean that the present disclosure necessarily has the first element, component, region, layer or part.

[0021] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0024] The embodiments of the present application aim to provide a calcium-silicon tandem solar cell and a preparation method thereof, and a photovoltaic module. The perovskite cell is connected to the positive electrode (high end) and / or the negative electrode (low end) between the sub-regions through the positive electrode connection area and / or the negative electrode connection area to complete the parallel connection between the sub-regions, and the multiple sub-perovskite cells in the sub-region are connected in series. The combination of series and parallel connection can effectively alleviate the problem of voltage matching difference between the perovskite cell and the silicon-based cell, and at the same time facilitate the generation of balanced and stable current, improve the stability of the device, and effectively and stably transmit the current generated in the battery to the external circuit, thereby significantly improving the photoelectric conversion efficiency and stability of the calcium-silicon stacked solar cell; the parallel connection between the sub-regions is completed by the buried conductive wire, which does not affect the series connection between the multiple sub-perovskite cells in the sub-region, and the combination effect between the functional layers is better, which can not only ensure that the battery has sufficient mechanical strength, but also effectively reduce the shading effect and contact resistance, thereby reducing energy loss and improving the photoelectric conversion efficiency and stability of the calcium-silicon stacked solar cell; when the perovskite cell and the crystalline silicon cell are stacked, they have a stable interconnection structure, and the process route is consistent with the process route of the single-section perovskite solar cell, without iterative equipment, and the technology is mature and can be mass-produced.

[0025] The embodiment of the present application provides a calcium-silicon tandem solar cell, including a perovskite cell, wherein the perovskite cell includes a substrate, a transparent conductive layer, a functional layer, and a top electrode stacked in sequence; The perovskite cell is divided into a plurality of sub-regions by a positive electrode connection region and / or a negative electrode connection region; one or more groups of P1 grooves, P2 grooves, and P3 grooves are arranged in sequence in any sub-region along the lateral direction of the perovskite cell, so as to divide the perovskite cell in the sub-region into a plurality of sub-perovskite cells connected in series; A first wire groove is provided in the positive electrode connection area, a second wire groove is provided in the negative electrode connection area, and conductive wires are provided in both the first and second wire grooves; the multiple sub-areas are connected in parallel through the conductive wires in the first wire groove and / or the conductive wires in the second wire groove; the top surface of the conductive wire is on the same horizontal plane as the top surface of the transparent conductive layer; the first wire groove, the second wire groove, and the P1 groove respectively penetrate the transparent conductive layer; the P2 groove penetrates the functional layer; and the P3 groove penetrates the top electrode.

[0026] In the embodiment of the present application, Figure 5As shown, the positive electrode connection area, the negative electrode connection area, and the positive electrode connection area are arranged in sequence to separate the perovskite sub-cell into 4 sub-areas, and then the busbars are used to complete the parallel connection between multiple sub-areas, and the sub-perovskite batteries in each sub-area are connected in series. It should be noted that the number and arrangement of the positive electrode connection area and the negative electrode connection area can be set according to actual needs, and the busbars are used to complete the parallel connection between multiple sub-areas; in addition, the sub-perovskite batteries in each sub-area are connected in series.

[0027] In the embodiment of the present application, the material of the transparent conductive layer includes one or more of indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (FTO) and antimony-doped tin oxide (ATO); the thickness of the transparent conductive layer can be 20-200nm (for example, 20nm, 30nm, 40nm, 80nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm). The preparation method of the transparent conductive layer may include one or more of electrochemical deposition, sputtering and atomic layer deposition.

[0028] In the embodiment of the present application, the functional layer may include a hole transport layer, a perovskite light absorption layer, and an electron transport layer, and may include other additional layers as needed.

[0029] The material of the hole transport layer may include one or more of Spiro-OMeTAD, triphenylamine derivatives, CuI, CuSCN, Cu2ZnSnS4, CuO, Cu2O, 2PACz, and MeO-2PACz; the thickness of the hole transport layer may be 1-100 nm (for example, 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, and 100 nm). The thickness of the hole transport layer is. The preparation method of the hole transport layer may include one or more of spin coating, spray coating, electrochemical deposition, sputtering, and atomic layer deposition.

[0030] The materials of the electron transport layer may include TiO2, ZnO, WO3, SnO2, Zn2SnO4, C 60 、PC 61 The thickness of the electron transport layer may be 10-200 nm (e.g., 10 nm, 20 nm, 30 nm, 40 nm, 80 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm). The preparation method of the electron transport layer may include one or more of spin coating, spray coating, spray pyrolysis, slit coating, and atomic layer deposition.

[0031] The perovskite light absorption layer is made of a perovskite material, and the perovskite material may be an ABX3 structure; A is a monovalent cation; B is a divalent cation; and X is a monovalent anion. More specifically, A includes but is not limited to a mixture of one or more monovalent cations selected from cesium (Cs), rubidium (Rb), methylamine (CH3NH3), and guanidine (CH2(NH2)2); B includes but is not limited to a mixture of one or more divalent cations selected from lead (Pb), copper (Cu), zinc (Zn), gallium (Ga), tin (Sn), and calcium (Ca); and X includes but is not limited to a mixture of one or more monovalent anions selected from iodine (I), bromine (Br), chlorine (Cl), fluorine (F), and thiocyanate ion (SCN). The thickness of the perovskite light absorbing layer may be 400-1500 nm (eg, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, 1100 nm, 1200 nm, 1500 nm). The preparation method of the perovskite light absorbing layer may include one or more of spin coating, spray coating, and slit coating.

[0032] In the embodiment of the present application, the material of the top electrode may include one or more transparent conductive materials; the preparation method of the top electrode may include one or more of evaporation, magnetron sputtering, printing, spin coating, scraping, spraying, spray pyrolysis, and slit coating. The thickness of the top electrode may be 20-200nm (for example, 20nm, 30nm, 40nm, 80nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm).

[0033] In an embodiment of the present application, the material of the conductive wire may include one or more of a transparent conductive material, silver (Ag), copper (Cu), and aluminum (Al); the preparation method of the conductive wire may include one or more of an electrochemical deposition method and a magnetron sputtering method.

[0034] In the embodiment of the present application, the P1 groove, P2 groove, P3 groove, first wire groove and second wire groove can be scratched by one or more of mechanical scratching, nanosecond infrared laser scratching, picosecond infrared laser scratching, femtosecond infrared laser scratching and picosecond ultraviolet laser scratching.

[0035] In the embodiment of the present application, the perovskite battery is used to connect the positive electrode (high end) and / or the negative electrode (low end) between the sub-regions through the positive electrode connection area and / or the negative electrode connection area to each other, thereby completing the parallel connection between the sub-regions, and the multiple sub-perovskite batteries in the sub-regions are connected in series. The combination of series and parallel connection can effectively alleviate the problem of voltage matching difference between the perovskite battery and the silicon-based battery, and at the same time facilitate the generation of balanced and stable current, improve the stability of the device, and effectively and stably transmit the current generated in the battery to the external circuit, thereby significantly improving the light efficiency of the calcium-silicon laminated solar cell. Electrical conversion efficiency and stability; the parallel connection between sub-regions is completed through buried conductive wires, which does not affect the series connection between multiple sub-perovskite batteries in the sub-region, and the combination effect between the functional layers is better, which can not only ensure that the battery has sufficient mechanical strength, but also effectively reduce the shading effect and contact resistance, thereby reducing energy loss and improving the photoelectric conversion efficiency and stability of calcium-silicon stacked solar cells; when the perovskite battery and the crystalline silicon battery are stacked, they have a stable interconnection structure, and the process route is consistent with the process route of a single-cell perovskite solar cell, without the need for iterative equipment, and the technology is mature and can be mass-produced.

[0036] In an optional embodiment, one or more groups of first groove groups, P2 grooves, first wire grooves, P2 grooves, and one or more groups of second groove groups are sequentially arranged in the positive electrode connection area along the lateral direction of the perovskite battery; And / or, one or more groups of second groove groups, P1 grooves, second wire grooves, P1 grooves, and one or more groups of first groove groups are sequentially arranged in the negative electrode connection area along the lateral direction of the perovskite battery; a P2 groove is also arranged directly above the second wire groove, and the second wire groove is directly connected to the adjacent P1 groove; The first groove group includes groove P1, groove P2 and groove P3, and groove P2 is located on one side of groove P1; the second groove group includes groove P1, groove P2 and groove P3, and groove P2 is located on the other side of groove P1.

[0037] In an embodiment of the present application, the first groove group includes P2 grooves, P1 grooves, and P3 grooves arranged in sequence along the lateral direction of the perovskite cell; or the first groove group includes P3 grooves, P2 grooves, and P1 grooves arranged in sequence along the lateral direction of the perovskite cell; the second groove group includes P1 grooves, P2 grooves, and P3 grooves arranged in sequence along the lateral direction of the perovskite cell; or the second groove group includes P3 grooves, P1 grooves, and P2 grooves arranged in sequence along the lateral direction of the perovskite cell.

[0038] In the embodiment of the present application, grooves are engraved on both sides of the first wire groove and the second wire groove, which can optimize the microscopic circuit of the first wire groove and the second wire groove, play a role in optimizing the current circuit and distribution, make the current distribution in the series-parallel circuit more uniform, and thus improve the photoelectric conversion efficiency of the calcium-silicon stacked solar cell.

[0039] In an optional embodiment, the first conductive groove sequentially penetrates the transparent conductive layer and a portion of the substrate, and the depth of the first conductive groove does not exceed one third of the thickness of the substrate; And / or, the second conductive groove sequentially penetrates the transparent conductive layer and a portion of the substrate, and the depth of the second conductive groove does not exceed one third of the thickness of the substrate.

[0040] In the embodiment of the present application, controlling the depth of the first wire groove and the second wire groove, that is, controlling the thickness of the first wire groove and the second wire groove engraved into the substrate and the thickness of the conductive wire, can not only ensure that the battery has sufficient mechanical strength, but also be beneficial to generating a balanced and stable current, thereby improving the stability of the device. At the same time, the current generated in the battery can be effectively and stably transmitted to the external circuit, thereby significantly improving the photoelectric conversion efficiency and stability of the calcium-silicon laminated solar cell.

[0041] In an optional embodiment, the thickness of the conductive line is greater than the thickness of the transparent conductive layer.

[0042] In the embodiment of the present application, the depth of the P1 groove is controlled to be smaller than the depth of the first wire groove and the second wire groove, that is, the P1 groove only penetrates the transparent conductive layer, and after the first wire groove and the second wire groove penetrate the transparent conductive layer, they are slightly engraved into the substrate, and then conductive wires are arranged in the first wire groove and the second wire groove (the depth of the first wire groove and the second wire groove is the thickness of the conductive wire); thickening the thickness of the conductive wire facilitates the generation of balanced and stable current, improves the stability of the device, and at the same time can effectively and stably transmit the current generated in the battery to the external circuit, thereby significantly improving the photoelectric conversion efficiency and stability of the calcium-silicon laminated solar cell.

[0043] In an optional embodiment, the material of the conductive wire includes one or more of silver and copper. Optimizing the material of the conductive wire is beneficial to generating a balanced and stable current, improving the stability of the device, and can effectively and stably transmit the current generated in the battery to the external circuit, thereby significantly improving the photoelectric conversion efficiency and stability of the calcium-silicon tandem solar cell.

[0044] In an optional embodiment, the spacing between adjacent P1 grooves is recorded as D1, and the spacing between the first conductive line groove and its adjacent P1 groove is recorded as D2; D1 and D2 satisfy: D1=D2.

[0045] In the embodiment of the present application, controlling the spacing between the P1 groove and the first conductive wire groove can make the current distribution in the series-parallel circuit more uniform, thereby improving the photoelectric conversion efficiency of the calcium-silicon stacked solar cell.

[0046] In an optional embodiment, the spacing between adjacent P1 grooves is 4-15 mm (for example, 4 mm, 6 mm, 8 mm, 10 mm, 12 mm, 14 mm, 15 mm).

[0047] In the embodiment of the present application, controlling the spacing between the P1 groove and the first conductive wire groove can make the current distribution in the series-parallel circuit more uniform, thereby improving the photoelectric conversion efficiency of the calcium-silicon stacked solar cell.

[0048] In an optional embodiment, a crystalline silicon cell is also included; the crystalline silicon cell and the perovskite cell are stacked.

[0049] In the embodiments of the present application, crystalline silicon cells include but are not limited to TopCON cells, heterojunction cells (HJT), and back contact cells (IBC). In the embodiments of the present application, when the perovskite cell and the crystalline silicon cell are stacked, they have a stable interconnection structure, and the process route is consistent with the process route of a single-cell perovskite solar cell, without the need for iterative equipment, and the technology is mature and can be mass-produced.

[0050] The present application also provides a method for preparing a calcium-silicon tandem solar cell, comprising: preparing a perovskite cell; wherein the method for preparing the perovskite cell comprises: Prepare a transparent conductive layer on a substrate; scratch a P1 groove, a first conductive groove and / or a second conductive groove penetrating the transparent conductive layer on the transparent conductive layer; After providing the P1 groove, the first conductive line groove and / or the second conductive line groove, preparing a conductive line in each conductive line groove; After preparing the conductive wire, a hole transport layer, a perovskite light absorption layer, and an electron transport layer are sequentially prepared on the transparent conductive layer; a P2 groove is carved on the electron transport layer, which sequentially penetrates the electron transport layer, the perovskite light absorption layer, and the hole transport layer; On the electron transport layer where the P2 groove has been carved, a top electrode is prepared; on the top electrode, a P3 groove penetrating the top electrode is carved to obtain a perovskite cell including a plurality of sub-perovskite cells; Wherein, the first conducting groove is arranged in the positive electrode connection area, and the second conducting groove is arranged in the negative electrode connection area; the perovskite battery is divided into a plurality of sub-areas by the positive electrode connection area and / or the negative electrode connection area; any of the plurality of sub-areas is provided with one or more groups of P1 grooves, P2 grooves, and P3 grooves arranged in sequence along the lateral direction of the perovskite battery, so as to divide the perovskite battery in the sub-area into a plurality of sub-perovskite batteries connected in series; the plurality of sub-areas are connected in parallel through the conductive wires in the first conducting groove and / or the conductive wires in the second conducting groove.

[0051] In the embodiment of the present application, when the perovskite cell and the crystalline silicon cell are stacked, they have a stable interconnection structure, and the process route is consistent with the process route of a single-cell perovskite solar cell. There is no need for iterative equipment, and the technology is mature and can be mass-produced.

[0052] The following specific examples further illustrate the present application, but should not be construed as limiting the present application. Without departing from the spirit and substance of the present application, modifications or replacements made to the methods, steps or conditions of the present application are within the scope of the present application.

[0053] Example 1 Calcium-silicon tandem solar cells, including perovskite cells, such as Figure 2 , Figure 4 As shown, the perovskite cell comprises a substrate 1, a transparent conductive layer 2, a hole transport layer 3, a perovskite light absorption layer 4, an electron transport layer 5, and a top electrode 6 which are stacked in sequence; The perovskite battery is divided into a plurality of sub-regions by a positive electrode connection region and a negative electrode connection region; one or more groups of P1 grooves, P2 grooves, and P3 grooves are arranged in sequence in any sub-region along the lateral direction of the perovskite battery, so as to divide the perovskite battery in the sub-region into a plurality of sub-perovskite batteries connected in series; A first wire groove P11 is provided in the positive electrode connection area, a second wire groove P12 is provided in the negative electrode connection area, and a conductive wire 7 is provided in each wire groove; the plurality of sub-areas are connected in parallel through the conductive wire 7 in the first wire groove P11 and the conductive wire 7 in the second wire groove P12; the top surface of the conductive wire 7 is on the same horizontal plane as the top surface of the transparent conductive layer 2; the first wire groove P11, the second wire groove P12, and the P1 groove penetrate the transparent conductive layer 2 respectively; the P2 groove penetrates the functional layer (hole transport layer 3, perovskite light absorption layer 4, electron transport layer 5); the P3 groove penetrates the top electrode 6; Wherein, the positive electrode connection area is as follows Figure 2As shown, in the positive electrode connection area, a P2 groove, a P1 groove, a P3 groove, a P2 groove, a first wire groove P11, a P2 groove, a P3 groove, a P1 groove, and a P2 groove are sequentially arranged along the lateral direction of the perovskite battery; The negative electrode connection area is as follows Figure 4 As shown, the negative electrode connection area is provided with a P1 groove, a P2 groove, a P3 groove, a P1 groove, a second wire groove P12, a P1 groove, a P3 groove, a P2 groove, and a P1 groove in sequence along the lateral direction of the perovskite battery; a P2 groove is also provided directly above the second wire groove P12, and the second wire groove P12 is directly connected to the adjacent P1 groove; the parallel connection between the positive electrode connection area and the negative electrode connection area is as shown in FIG. Figure 5 As shown, the perovskite battery is divided into four sub-areas by sequentially arranging the positive electrode connection area, the negative electrode connection area, and the positive electrode connection area, and a bus bar is used to complete the parallel connection between the four sub-areas; wherein, the spacing between adjacent P1 grooves is 5 mm, and the spacing between the first wire groove P11 and its adjacent P1 groove is 5 mm.

[0054] The calcium silicon tandem solar cell is obtained by stacking a crystalline silicon cell and a perovskite cell, wherein the crystalline silicon cell is used as the bottom cell. The specific preparation process of the perovskite cell is as follows: (1) Using indium tin oxide (ITO) as a raw material, a transparent conductive layer 2 with a thickness of 100 nm is prepared on a substrate by sputtering; laser-scribing a P1 groove, a first conductive groove P11, and a second conductive groove P12 penetrating the transparent conductive layer 2 on the transparent conductive layer 2; (2) using silver as a raw material and adopting an electrochemical deposition method to prepare conductive wires 7 in each conductive wire slot; (3) using PVD technology (physical vapor deposition technology) to prepare a NiOx layer with a thickness of 30 nm on the transparent conductive layer 2 as a hole transport layer 3; (4) depositing a perovskite light absorption layer 4 on the hole transport layer 3 by a one-step spin coating method; the band gap of the perovskite light absorption layer 4 is about 1.85 eV and the thickness is 600 nm; (5) A 20 nm thick C film was prepared on the perovskite light absorption layer 4 by thermal evaporation. 60 layer, using atomic layer deposition on C 60 A SnO layer with a thickness of 10 nm was prepared on the X Layer, C 60 layer, SnO X The layers together constitute the electron transport layer 5; (6) Using a laser to carve a P2 groove on the electron transport layer 5 that penetrates the electron transport layer 5, the perovskite light absorption layer 4, and the hole transport layer 3 in sequence; at this time, the positive electrode connection area is as follows Figure 1 As shown, the negative electrode connection area is Figure 3 As shown; (7) A top electrode 6 with a thickness of 200 nm is prepared on the electron transport layer 5 by using PVD technology (physical vapor deposition technology); the material of the top electrode 6 is indium tin oxide (ITO); a P3 groove penetrating the top electrode 6 is engraved on the top electrode 6; at this time, the positive electrode connection area is as follows Figure 2 As shown, the negative electrode connection area is Figure 4 As shown; the arrangement of the P1 groove, P2 groove, and P3 groove of the perovskite cell is as follows Figure 6 As shown, the bus bar is used to complete the parallel connection, and the setting of the bus bar can be adjusted according to actual needs.

[0055] Example 2 The calcium-silicon tandem solar cell of Example 2 was prepared by referring to the preparation method of Example 1, except that the thickness of the conductive wire 7 in Example 2 was 110 nm (the thickness of the conductive wire 7 in Example 1 was 100 nm).

[0056] Example 3 The calcium-silicon tandem solar cell of Example 3 was prepared by referring to the preparation method of Example 1, except that the thickness of the conductive wire 7 in Example 3 was 120 nm (the thickness of the conductive wire 7 in Example 1 was 100 nm).

[0057] Example 4 The calcium-silicon tandem solar cell of Example 4 is prepared by referring to the preparation method of Example 1, except that in Example 4, indium tin oxide (ITO) is used as the raw material and the electrochemical deposition method is adopted to prepare the conductive wires 7 in each conductive groove.

[0058] Example 5 The calcium-silicon stacked solar cell of Example 5 is prepared by referring to the preparation method of Example 1, with the only difference being that in Example 5, the spacing between adjacent P1 grooves is 5 mm, and the spacing between the first wire groove P11 and its adjacent P1 groove is 4 mm (in Example 1, the spacing between adjacent P1 grooves is 5 mm, and the spacing between the first wire groove P11 and its adjacent P1 groove is 5 mm).

[0059] Example 6 The calcium-silicon stacked solar cell of Example 6 is prepared by referring to the preparation method of Example 1, with the only difference being that in Example 6, the spacing between adjacent P1 grooves is 5 mm, and the spacing between the first wire groove P11 and its adjacent P1 groove is 6 mm (in Example 1, the spacing between adjacent P1 grooves is 5 mm, and the spacing between the first wire groove P11 and its adjacent P1 groove is 5 mm).

[0060] Comparative Example 1 The calcium-silicon laminated solar cell in comparative example 1 was prepared by referring to the preparation method of example 1, except that: no positive electrode connection area and negative electrode connection area were provided, and only the busbars were attached to complete the parallel connection between the sub-regions, and the multiple sub-perovskite cells in each sub-region were connected in series. The arrangement of the P1 groove, P2 groove, and P3 groove of the perovskite cell is as follows: Figure 7 As shown, the bus bar is used to complete the parallel connection, and the setting of the bus bar can be adjusted according to actual needs.

[0061] The perovskite cell prepared in the above embodiment was subjected to a photoelectric test (that is, the various properties of the perovskite cell were tested before the crystalline silicon cell and the perovskite cell were stacked). The performance test results of the perovskite cell are shown in Table 1 below.

[0062] Table 1 Device performance data

[0063] Referring to the above test data, it can be seen that the perovskite battery is used to connect the positive electrode (high end) and the negative electrode (low end) between the sub-regions through the positive electrode connection area and the negative electrode connection area to each other, thereby completing the parallel connection between the sub-regions, and the multiple sub-perovskite batteries in the sub-region are connected in series. The combination of series and parallel connection is adopted to facilitate the generation of balanced and stable current, improve the stability of the device, and effectively and stably transmit the current generated in the battery to the external circuit, thereby significantly improving the photoelectric conversion efficiency and stability of the perovskite battery; the parallel connection between the sub-regions is completed by the buried conductive wire 7, which does not affect the series connection between the multiple sub-perovskite batteries in the sub-region, and the combination effect between the functional layers is better, which can not only ensure that the battery has sufficient mechanical strength, but also effectively reduce the shading effect and contact resistance, thereby reducing energy loss and improving the photoelectric conversion efficiency and stability of the perovskite battery.

[0064] In addition, it should be noted that the stability of the calcium-silicon tandem solar cells prepared in the above embodiments 1-6 is higher than that of the calcium-silicon tandem solar cells prepared in comparative example 1; the photoelectric conversion efficiency of the calcium-silicon tandem solar cells prepared in the above embodiments 1-6 is higher than that of the calcium-silicon tandem solar cells prepared in comparative example 1. It can be seen that the perovskite cell is used to connect the positive electrode (high end) and / or the negative electrode (low end) between the sub-regions through the positive electrode connection area and / or the negative electrode connection area to each other, thereby completing the parallel connection between the sub-regions, and the multiple sub-perovskite cells in the sub-regions are connected in series. The combination of series and parallel connection can effectively alleviate the problem of poor voltage matching between the perovskite cell and the silicon-based cell, and at the same time facilitate the generation of balanced and stable current, improve the stability of the device, and effectively and stably transmit the current generated in the battery to the external circuit, thereby significantly improving the photoelectric conversion efficiency of the calcium-silicon tandem solar cell. Efficiency and stability; the parallel connection between sub-regions is completed through buried conductive wires, which does not affect the series connection between multiple sub-perovskite cells in the sub-region, and the combination effect between the functional layers is better, which can not only ensure that the battery has sufficient mechanical strength, but also effectively reduce the shading effect and contact resistance, thereby reducing energy loss and improving the photoelectric conversion efficiency and stability of calcium-silicon stacked solar cells; when the perovskite cell and the crystalline silicon cell are stacked, they have a stable interconnection structure, and the process route is consistent with that of a single-cell perovskite solar cell, without the need for iterative equipment, and the technology is mature and can be mass-produced.

[0065] Referring to the detection data of the above-mentioned embodiment 1 and embodiments 2-3, it can be known that thickening the thickness of the conductive wire 7 facilitates the generation of a balanced and stable current, improves the stability of the device, and can effectively and stably transmit the current generated in the battery to the external circuit, thereby significantly improving the photoelectric conversion efficiency and stability of the calcium-silicon laminated solar cell.

[0066] Referring to the detection data of the above-mentioned Examples 1 and 4, it can be seen that optimizing the material of the conductive wire 7 is beneficial to generating a balanced and stable current and improving the stability of the device. At the same time, the current generated in the battery can be effectively and stably transmitted to the external circuit, thereby significantly improving the photoelectric conversion efficiency and stability of the calcium-silicon laminated solar cell.

[0067] Referring to the detection data of the above-mentioned embodiment 1 and embodiments 5-6, it can be known that controlling the spacing between the P1 groove and the first conductive groove P11 can make the current distribution in the series-parallel circuit more uniform, thereby improving the photoelectric conversion efficiency of the calcium-silicon stacked solar cell.

[0068] The present application also provides a photovoltaic module, including: the calcium-silicon tandem solar cell as described above; or the calcium-silicon tandem solar cell prepared by the preparation method as described above. The photovoltaic module also has the advantages of the calcium-silicon tandem solar cell, which will not be repeated here.

[0069] It should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0070] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0071] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0072] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A calcium silicon tandem solar cell, characterized in that: A perovskite cell is provided, wherein the perovskite cell comprises a substrate, a transparent conductive layer, a functional layer, and a top electrode stacked in sequence; The perovskite cell is divided into a plurality of sub-regions by a positive electrode connection region and / or a negative electrode connection region; one or more groups of P1 grooves, P2 grooves, and P3 grooves are arranged in sequence in any sub-region along the lateral direction of the perovskite cell, so as to divide the perovskite cell in the sub-region into a plurality of sub-perovskite cells connected in series; A first wire groove is provided in the positive electrode connection area, a second wire groove is provided in the negative electrode connection area, and conductive wires are provided in both the first and second wire grooves; the multiple sub-areas are connected in parallel through the conductive wires in the first wire groove and / or the conductive wires in the second wire groove; the top surface of the conductive wire is on the same horizontal plane as the top surface of the transparent conductive layer; the first wire groove, the second wire groove, and the P1 groove respectively penetrate the transparent conductive layer; the P2 groove penetrates the functional layer; and the P3 groove penetrates the top electrode.

2. The calcium-silicon tandem solar cell according to claim 1, characterized in that: In the positive electrode connection area, one or more groups of first groove groups, P2 grooves, first wire grooves, P2 grooves, and one or more groups of second groove groups are sequentially arranged along the lateral direction of the perovskite battery; And / or, one or more groups of second groove groups, P1 grooves, second wire grooves, P1 grooves, and one or more groups of first groove groups are sequentially arranged in the negative electrode connection area along the lateral direction of the perovskite battery; a P2 groove is also arranged directly above the second wire groove, and the second wire groove is directly connected to the adjacent P1 groove; The first groove group includes groove P1, groove P2 and groove P3, and groove P2 is located on one side of groove P1; the second groove group includes groove P1, groove P2 and groove P3, and groove P2 is located on the other side of groove P1.

3. The calcium-silicon tandem solar cell according to claim 1, characterized in that: The first conductive groove sequentially penetrates the transparent conductive layer and a portion of the substrate, and the depth of the first conductive groove does not exceed one third of the thickness of the substrate; And / or, the second conductive groove sequentially penetrates the transparent conductive layer and a portion of the substrate, and the depth of the second conductive groove does not exceed one third of the thickness of the substrate.

4. The calcium-silicon tandem solar cell according to claim 3, characterized in that: The thickness of the conductive line is greater than the thickness of the transparent conductive layer.

5. The calcium-silicon tandem solar cell according to claim 1, characterized in that: The material of the conductive wire includes one or more of silver and copper.

6. The calcium-silicon tandem solar cell according to claim 2, characterized in that: The distance between adjacent P1 grooves is recorded as D1, and the distance between the first conductive line groove and its adjacent P1 groove is recorded as D2; D1 and D2 satisfy: D1=D2.

7. The calcium-silicon tandem solar cell according to claim 6, characterized in that: The spacing between adjacent P1 grooves is 4-15 mm.

8. The calcium-silicon tandem solar cell according to any one of claims 1 to 7, characterized in that: It also includes a crystalline silicon cell; the crystalline silicon cell and the perovskite cell are stacked.

9. A method for preparing a calcium silicon tandem solar cell, characterized in that: include: Prepare a perovskite battery; wherein the preparation method of the perovskite battery comprises: Prepare a transparent conductive layer on a substrate; scratch a P1 groove, a first conductive groove and / or a second conductive groove penetrating the transparent conductive layer on the transparent conductive layer; After providing the P1 groove, the first conductive line groove and / or the second conductive line groove, preparing a conductive line in each conductive line groove; After preparing the conductive wire, a hole transport layer, a perovskite light absorption layer, and an electron transport layer are sequentially prepared on the transparent conductive layer; a P2 groove is carved on the electron transport layer, which sequentially penetrates the electron transport layer, the perovskite light absorption layer, and the hole transport layer; On the electron transport layer where the P2 groove has been carved, a top electrode is prepared; on the top electrode, a P3 groove penetrating the top electrode is carved to obtain a perovskite cell including a plurality of sub-perovskite cells; Wherein, the first conducting groove is arranged in the positive electrode connection area, and the second conducting groove is arranged in the negative electrode connection area; the perovskite battery is divided into a plurality of sub-areas by the positive electrode connection area and / or the negative electrode connection area; any of the plurality of sub-areas is provided with one or more groups of P1 grooves, P2 grooves, and P3 grooves arranged in sequence along the lateral direction of the perovskite battery, so as to divide the perovskite battery in the sub-area into a plurality of sub-perovskite batteries connected in series; the plurality of sub-areas are connected in parallel through the conductive wires in the first conducting groove and / or the conductive wires in the second conducting groove.

10. A photovoltaic module, characterized in that: include: The calcium-silicon tandem solar cell according to any one of claims 1 to 8; or A calcium-silicon tandem solar cell prepared by the preparation method as described in claim 9.

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