Perovskite layer and method of preparation, solar cell, tandem cell, photovoltaic module

Abstract

The present application relates to the technical field of solar cells, and particularly provides a perovskite layer, a preparation method thereof, a solar cell, a stacked cell and a photovoltaic module, aiming to solve the problem of performance reduction of a perovskite solar cell caused by leakage of perovskite solution on the upper surface to the back surface during preparation of the perovskite layer in the prior art. To this end, the perovskite layer structure comprises a substrate, a first functional layer arranged on the substrate, and a perovskite material layer arranged on the first functional layer, wherein the perovskite material layer and the first functional layer have a non-overlapping area in the horizontal plane. The present application can reduce or avoid the performance reduction of the perovskite solar cell caused by pollution of the effective area on the back surface by the solution or the effective component, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, specifically providing a perovskite layer and its preparation method, a solar cell, a tandem cell, and a photovoltaic module. Background Technology

[0002] Perovskite solar cells have advantages such as excellent photoelectric performance and low cost. Furthermore, the band gap of perovskite materials is adjustable, and they can be stacked in multiple layers or stacked with other photovoltaic materials to form tandem solar cells, thereby achieving higher photoelectric conversion efficiency and showing great application potential.

[0003] Currently, the main methods for preparing perovskite layers include one-step and two-step methods. The one-step method involves preparing the perovskite raw material into a solution, and then forming a film in one step using methods such as spin coating, slot coating, or blade coating. The two-step method involves separating the perovskite raw material into two parts (inorganic salt and organic salt). First, the inorganic salt is deposited on the substrate surface to form an inorganic framework layer, and then the organic salt is deposited on the surface of the inorganic framework layer, reacting to form the perovskite layer.

[0004] However, regardless of whether it is a one-step or two-step method, during the fabrication process, the perovskite solution on the upper surface of the substrate is prone to leaking to the back side, contaminating the effective area on the back side and reducing the performance of the perovskite solar cell.

[0005] Accordingly, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0006] The present invention aims to solve the above-mentioned technical problem, namely, to solve the problem in the prior art that the performance of perovskite solar cells is reduced due to the leakage of perovskite solution from the upper surface to the back side during the preparation of the perovskite layer.

[0007] In a first aspect, the present invention provides a perovskite layer structure, comprising:

[0008] Base;

[0009] A first functional layer is disposed on the substrate;

[0010] A perovskite material layer disposed on the first functional layer;

[0011] The perovskite material layer and the first functional layer have a non-overlapping region when projected onto the horizontal plane.

[0012] When the above technical solution is adopted, there are non-overlapping areas on the first functional layer that are not covered by the perovskite material layer. In this way, during the preparation of the perovskite material layer, the solution or active ingredients will not be spread all over the surface of the first functional layer. This can prevent the solution or active ingredients from penetrating to the back side, reduce or avoid the situation where the performance of the solar cell with the perovskite layer structure is reduced due to the solution or active ingredients contaminating the effective area on the back side, and effectively improve the photoelectric conversion efficiency of the perovskite solar cell.

[0013] In the preferred embodiment of the above perovskite layer structure, the non-overlapping region is the exposed surface of the first functional layer that is not covered by the perovskite material layer.

[0014] In the preferred embodiment of the above-mentioned perovskite layer structure, the exposed surface forms a closed ring around the perovskite material layer.

[0015] In the preferred embodiment of the above-mentioned perovskite layer structure, the exposed surfaces are located only on opposite sides of the perovskite material layer.

[0016] In the preferred embodiment of the above perovskite layer structure, the maximum dimension L of the non-overlapping region in the direction parallel to the substrate plane satisfies: 0 < L ≤ 0.2 mm.

[0017] Secondly, this invention also proposes a method for preparing a perovskite layer structure.

[0018] Provide a substrate; form a first functional layer on the substrate; form a perovskite material layer on a portion of the surface of the first functional layer by spatially selective deposition, such that there is a non-overlapping region between the perovskite material layer and the first functional layer in a horizontal plane, wherein the non-overlapping region is the exposed surface of the first functional layer that is not covered by the perovskite material layer.

[0019] In the preferred embodiment of the above preparation method, the spatial selective deposition is a patterned solution method, in which a perovskite precursor solution is directly coated onto the surface of the portion, and a perovskite material layer is formed by heat treatment.

[0020] In the preferred embodiment of the above preparation method, the spatial selective deposition is a vapor deposition method, in which the component materials constituting the perovskite are deposited in vapor form on the surface of the portion, and a perovskite material layer is formed by heat treatment.

[0021] In the preferred embodiment of the above preparation method, the spatially selective deposition is a sequential deposition method, which includes: first forming an inorganic precursor layer on the first functional layer; then applying an organic salt solution to at least a portion of the surface of the inorganic precursor layer to react and generate a perovskite material layer.

[0022] When the above technical solution is adopted, the raw materials for forming the perovskite material layer are confined to a portion of the surface of the first functional layer during the preparation of the perovskite material layer. At least a portion of the surface of the first functional layer is not covered by the perovskite material layer. This reduces or avoids the chance of organic salt solution penetrating to the back of the first functional layer due to coating to the edge of the first functional layer. This reduces the probability of the performance of the solar cell with the perovskite layer structure being reduced due to organic salt solution contaminating the effective area on the back, thereby improving the photoelectric conversion efficiency of the solar cell.

[0023] Thirdly, the present invention also provides a perovskite solar cell, which includes the perovskite layer structure described in any of the foregoing embodiments or the perovskite layer structure prepared by the preparation method described in any of the foregoing embodiments.

[0024] It should be noted that this perovskite solar cell possesses all the technical effects of the aforementioned perovskite layer structure or preparation method, which will not be elaborated upon here.

[0025] Fourthly, the present invention also provides a stacked battery comprising a bottom battery and a top battery arranged sequentially, wherein the top battery is the aforementioned perovskite solar cell.

[0026] In the preferred embodiment of the above-mentioned stacked battery, the bottom battery is a crystalline silicon battery.

[0027] It should be noted that this tandem cell possesses all the technical advantages of the aforementioned perovskite solar cells, which will not be elaborated upon here.

[0028] Fourthly, the present invention also provides a photovoltaic module, which includes the aforementioned perovskite solar cell or tandem cell.

[0029] It should be noted that this photovoltaic module possesses all the technical effects of the aforementioned perovskite solar cells or tandem cells, which will not be elaborated upon here. Attached Figure Description

[0030] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0031] Figure 1 This is a top view of a perovskite layer structure according to an embodiment of the present invention;

[0032] Figure 2 This is a cross-sectional view of a perovskite layer structure formed on a first functional layer by spin coating according to an embodiment of the present invention.

[0033] Figure 3 This is a cross-sectional view (a) of a perovskite layer structure formed on the surface of a first functional layer by a sequential deposition method according to an embodiment of the present invention.

[0034] Figure 4 This is a cross-sectional view (II) of a perovskite layer structure formed on the surface of the first functional layer by a sequential deposition method according to an embodiment of the present invention.

[0035] Figure 5 This is a schematic diagram of the structure of a perovskite solar cell according to an embodiment of the present invention.

[0036] List of reference numerals in the attached diagram:

[0037] 1. Perovskite material layer; 2. Non-overlapping region; 3. Inorganic precursor layer. Detailed Implementation

[0038] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0039] It should be noted that in the description of this invention, the terms "left," "right," "up," "down," etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0040] Currently, during the fabrication of perovskite solar cells, solutions or active ingredients on the substrate surface can leak to the back side, contaminating the effective area and reducing the performance of the perovskite solar cell. To address this, this invention ensures that the orthogonal projection of the first functional layer on the substrate onto a horizontal plane includes a surface not covered by the perovskite material layer. This reduces or avoids the performance degradation caused by solution or active ingredient contamination of the effective area on the back side during perovskite material layer fabrication, effectively improving the photoelectric conversion efficiency of perovskite solar cells.

[0041] In one possible implementation, the present invention provides a perovskite layer structure, the perovskite layer structure including a substrate, a first functional layer disposed on the substrate, and a perovskite material layer disposed on the first functional layer, wherein the perovskite material layer and the first functional layer have a non-overlapping region in their orthogonal projections on a horizontal plane, the non-overlapping region being the exposed surface of the first functional layer not covered by the perovskite material layer.

[0042] Through in-depth research, the inventors of this application discovered that the main reason for leakage of the perovskite precursor solution or its active ingredients to the back side during the preparation of the perovskite material layer is that when the solution or active ingredients cover the entire surface of the substrate, they penetrate to the back side from its edges. To address this, the inventors of this application have created a perovskite material layer that covers a portion of the surface of the first functional layer, forming an exposed surface on the surface of the first functional layer that is not covered by the perovskite material layer. For example, viewed from above, the substrate, the first functional layer, and the perovskite material layer are all roughly rectangular, with a portion of the first functional layer exposed and not covered by the perovskite material layer. This means that the orthogonal projections of the perovskite material layer and the first functional layer on the horizontal plane do not overlap. This reduces or prevents the perovskite solution from penetrating to the back side, thereby reducing or preventing performance degradation of the perovskite solar cell due to contamination of the effective area on the back side, effectively improving the photoelectric conversion efficiency of the perovskite solar cell.

[0043] It should be noted that the first functional layer can be a hole transport layer, or other possible functional layers disposed between the substrate and the perovskite material layer.

[0044] In one possible implementation, the exposed surface forms a closed ring around the perovskite material layer. The first functional layer typically covers the entire substrate. This results in a distance between all sides of the perovskite material layer and the first functional layer, with exposed surfaces outside all sides of the first functional layer not covered by the perovskite material layer. Taking a rectangular substrate, first functional layer, and perovskite material layer viewed from above as examples, the exposed surface is roughly a ring-shaped area surrounding the perovskite material layer. That is, there is a distance between the four sides of the perovskite material layer and the four sides of the first functional layer and the substrate. The area of ​​the perovskite material layer is smaller than the areas of the first functional layer and the substrate, and it is located in the central region of the first functional layer. This avoids coating the perovskite precursor solution or the active ingredients required for preparing the perovskite material layer onto the edges of the first functional layer and then penetrating to the back side of the substrate. This better prevents the solution or active ingredients from penetrating to the back side of the substrate and contaminating the effective area, effectively improving the photoelectric conversion efficiency of the perovskite solar cell. For example, as... Figure 1 As shown, Figure 1 The diagram shows a schematic of the perovskite layer structure from a top-down perspective. The dark area in the diagram is the perovskite material layer 1, and the gray area is the non-overlapping area 2. The non-overlapping area 2 is the exposed surface of the first functional layer that is not covered by the perovskite material layer, forming a closed ring around the outside of the perovskite material layer 1.

[0045] In one possible implementation, the exposed surface is located only on opposite sides of the perovskite material layer. This creates a distance between the two opposite sides of the perovskite material layer and the first functional layer, and also between the two opposite sides of the substrate. Taking an example where the substrate, first functional layer, and perovskite material layer are all rectangular when viewed from above, the exposed surface is roughly two rectangular areas located on opposite sides of the perovskite material layer. In other words, the two opposite sides of the perovskite material layer are distanced from the corresponding two sides of the first functional layer and the substrate, and the other two sides extend to the corresponding sides of the first functional layer. This reduces the possibility of coating the first functional layer with solution or active ingredients, minimizing the risk of solar cell performance degradation due to solution or active ingredients penetrating to the back of the substrate and contaminating the effective area, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

[0046] It should be noted that the exposed surface may be located only on the outer side of one side of the perovskite material layer, or on the outer side of all three sides of the perovskite material layer, etc. It should also be noted that although the above example uses a regular rectangle as the perovskite material layer, it is clearly only an illustrative example and not a limitation. The perovskite material layer can obviously also be set as a square, circle, polygon, or other possible regular shape, or other possible irregular shape.

[0047] In one possible implementation, the maximum dimension L of the non-overlapping region in the direction parallel to the substrate plane satisfies: 0 < L ≤ 0.2 mm. For example, L can be 0.2 mm, 0.18 mm, 0.15 mm, 0.12 mm, 0.10 mm, 0.08 mm, 0.05 mm, etc. Taking a regular rectangle as an example, in this case, the shape of the non-overlapping region in the direction parallel to the substrate plane is approximately a ring structure, with two pairs of opposite rectangular regions. The dimension of the two opposite rectangular regions along the length direction of the perovskite material layer is L1, and the dimension of the two opposite rectangular regions along the width direction of the perovskite material layer is L2. The larger of L1 and L2 is greater than 0 and less than or equal to 0.2 mm. In this way, it is possible to avoid the organic salt solution from penetrating to the back side of the substrate and to ensure that a sufficient area of ​​perovskite material layer is formed on the first functional layer, thereby better ensuring the photoelectric conversion efficiency of the perovskite solar cell.

[0048] It should be noted that the dimensions of the non-overlapping region in the direction parallel to the substrate plane can be measured in the following way: draw the outer contour lines of the perovskite material layer and the first functional layer respectively, and measure the dimension between the two outer contour lines along the width or length direction of the first functional layer.

[0049] In one possible embodiment, the present invention also provides a method for preparing a perovskite layer structure, the method comprising the following steps:

[0050] S1: Provides the substrate.

[0051] In this embodiment, the substrate is a silicon wafer. Of course, the substrate can also be titanium foil, molybdenum foil, stainless steel foil, or other possible flexible substrates, or ceramic, graphite, or other possible heterogeneous substrates.

[0052] S2: The first functional layer is formed on the substrate.

[0053] As described above, the first functional layer can be a hole transport layer or other possible functional layers disposed between the substrate and the perovskite material layer.

[0054] S3: By spatially selectively depositing, a perovskite material layer is formed on a portion of the surface of the first functional layer, such that there is a non-overlapping area between the perovskite material layer and the first functional layer in the orthogonal projection on the horizontal plane. This non-overlapping area is the exposed surface of the first functional layer that is not covered by the perovskite material layer.

[0055] In other words, when forming the perovskite material layer on the surface of the first functional layer through spatial selection, at least a portion of the perovskite solution is not laid onto the surface of the first functional layer, ensuring that there is at least a partially exposed area on the surface of the first functional layer. This allows the orthographic projections of the perovskite material layer and the first functional layer on the horizontal plane to form a non-overlapping area, which is the exposed surface of the first functional layer not covered by the perovskite material layer. For example, viewed from above, the substrate, the first functional layer, and the perovskite material layer are all roughly rectangular. The first functional layer formed on the substrate covers the entire substrate, and the perovskite material layer formed on a portion of the surface of the first functional layer has a non-overlapping area on the horizontal plane with the orthographic projection of the first functional layer. This non-overlapping area is the roughly annular exposed surface of the first functional layer not covered by the perovskite material layer. This reduces or avoids the penetration of solution or active ingredients to the back side, thereby reducing or avoiding performance degradation of the perovskite solar cell due to contamination of the effective area on the back side, effectively improving the photoelectric conversion efficiency of the perovskite solar cell.

[0056] In one possible implementation, spatially selective deposition is a patterned solution method, in which a perovskite precursor solution is directly coated onto a portion of the surface of the first functional layer, followed by heat treatment to form a perovskite material layer. The patterned solution method can be inkjet printing, spin coating, slot coating, or blade coating.

[0057] like Figure 2 As shown, Figure 2 The diagram shows a cross-sectional view of a perovskite layer structure formed on the first functional layer by spin coating. Figure 2 In the diagram, the dark gray area at the bottom represents the substrate and the first functional layer. The surface of the substrate is textured, and the texture is represented by wavy lines. The light gray area above the textured surface represents the perovskite material layer 1. The perovskite material layer is located in the center of the first functional layer and the substrate. The non-overlapping area 2 is the exposed surface of the first functional layer surrounding the perovskite material layer 1.

[0058] In another embodiment, spatially selective deposition is performed using vapor deposition, where the components constituting the perovskite are deposited in vapor form on a portion of the surface of the first functional layer, followed by heat treatment to form the perovskite material layer. It should be noted that a single evaporation source can be used to evaporate the prepared perovskite precursor solution, causing it to be deposited in vapor form on a portion of the surface of the first functional layer. Alternatively, multiple evaporation sources can be used for co-evaporation, where multiple components forming the perovskite material layer are used as evaporation sources and evaporated together, each deposited in vapor form on a portion of the surface of the first functional layer, followed by heat treatment to form the perovskite material layer. For example, the components constituting the perovskite could be CsI, methyl ether iodide (FAI), PbI2, PbBr2, and methylamine chloride. These components are deposited in vapor form on a portion of the surface of the first functional layer, followed by heat treatment to obtain the perovskite material layer.

[0059] In another implementation, spatially selective deposition is a sequential deposition method, specifically including:

[0060] S11: First, an inorganic precursor layer is formed on the first functional layer.

[0061] S12: An organic salt solution is applied to a portion of the surface deposited on the inorganic precursor layer to react and generate a perovskite material layer.

[0062] The raw materials for forming the perovskite material layer are divided into two parts: an inorganic precursor material and an organic salt solution. The inorganic precursor material includes at least an inorganic lead salt, such as lead iodide or lead bromide, to ensure the photoelectric conversion efficiency of the perovskite material layer. First, the inorganic precursor material is deposited on the surface of the first functional layer using vapor deposition or patterned solution deposition to form an inorganic precursor layer that covers the entire surface of the first functional layer. Then, the organic salt solution is applied to a portion of the surface of the inorganic precursor layer using patterned solution deposition (e.g., inkjet printing, spin coating) or vapor deposition. For example, the organic salt solution is applied to the surface of the middle portion of the inorganic precursor layer. Then, annealing is performed under preset conditions. The organic salt solution reacts with the inorganic precursor material to form the perovskite material layer, which is located in the central region of the inorganic precursor layer. This ensures that the organic salt solution does not reach the edge of the substrate and therefore does not penetrate from the edge to the back side of the substrate. In this case, the outer edge of the perovskite material layer forms the aforementioned non-overlapping region. This non-overlapping region is covered by an inorganic precursor layer but does not form a perovskite material layer. In this way, the organic salt solution can be avoided from contaminating the back side of the substrate, thereby effectively improving the photoelectric conversion efficiency of the perovskite solar cell.

[0063] Therefore, the non-overlapping region can be an exposed surface on the first functional layer that is not covered by the perovskite material layer, or it can be a surface on the first functional layer that is covered by the inorganic precursor layer but not by the perovskite material layer.

[0064] For example, the substrate is roughly rectangular, the first functional layer covers the entire substrate, the inorganic precursor layer covers the entire first functional layer, and the organic salt solution is applied to a predetermined area of ​​the inorganic precursor layer. This predetermined area is located in the middle of the inorganic precursor layer and is roughly rectangular. In this way, the perovskite material layer generated by the reaction is also located in the predetermined area in the middle of the first functional layer, forming the aforementioned non-overlapping area around the circumference of the perovskite material layer. Figure 1 As shown, the perovskite material layer is located in the middle, and the non-overlapping region surrounds the outside of the perovskite material layer.

[0065] During the process of adding organic salt solution to the substrate, some organic salt solution will inevitably be sprayed onto the surface of the inorganic precursor layer outside the predetermined area, reacting with this portion of the inorganic precursor material. However, due to the small amount of organic salt solution, a complete perovskite phase cannot be formed; only a partially formed perovskite phase can be formed. In other words, the non-overlapping region can be a simple inorganic precursor layer, a partially formed perovskite phase, or a combination of both.

[0066] Of course, it is also possible that one pair of sides of the preset area, which are arranged opposite each other, overlaps with the side corresponding to the first functional layer, and the non-overlapping area is located outside the other pair of sides; or, the three sides of the preset area overlap with the side corresponding to the first functional layer, and the non-overlapping area is located outside the other side. Obviously, the preset area can also be a square, circle, polygon, or other possible regular shape, or other possible irregular shape, other than a rectangle.

[0067] In this way, the penetration of organic materials into the back of the substrate can be reduced or avoided, thus reducing or avoiding the effective area of ​​contamination on the back of the substrate and effectively improving the photoelectric conversion efficiency of perovskite solar cells.

[0068] It should be noted that inorganic precursor raw materials may consist only of inorganic lead salts, or they may be a mixture of inorganic lead salts and other inorganic salts (such as inorganic copper salts, inorganic cesium salts, inorganic tin salts, etc.).

[0069] Of course, the inorganic precursor layer may not cover the entire first functional layer. In other words, the inorganic precursor layer may not cover part of the surface of the first functional layer. In this case, even if the organic salt solution applied to the surface of the inorganic precursor layer is coated to the edge of the inorganic precursor layer, there will still be exposed surfaces on the first functional layer that are not covered by the perovskite material layer.

[0070] In one possible implementation, the preset conditions include: an annealing temperature of 130°C to 180°C, an annealing time of 10 min to 40 min, and an ambient humidity of 20% to 40%. That is, after applying the organic salt solution to part of the surface of the inorganic precursor layer, annealing is performed under the conditions of ambient humidity of 20% to 40% and temperature of 130°C to 180°C for 10 min to 40 min, so that the organic salt solution reacts with the inorganic precursor raw material to generate a perovskite material layer.

[0071] For example, the annealing temperature can be 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, etc., the annealing time can be 10min, 15min, 20min, 25min, 30min, 35min, 40min, etc., and the ambient humidity can be 20%, 25%, 30%, 35%, 40%, etc.

[0072] In one possible implementation, the perovskite material layer comprises an ABX3 type perovskite material, wherein A is a monovalent cation, B is a divalent cation, and X is a monovalent anion.

[0073] In one possible implementation, A is Cs. + 、Rb + One or more of methylamino and formamidinyl groups.

[0074] In one possible implementation, B is Pb. 2+ Cu 2+ Zn 2+ Ga 2+ Sn 2+ Ca 2+ One or more of them.

[0075] In one possible implementation, X is I. - ,Br - Cl - F - One or more of the thiocyanate ions.

[0076] For example, the inorganic precursor raw material can be BX2, which can be one or a mixture of inorganic salts such as PbI2, CuCl2, ZnCl2, GaBr2, and SnF2, or a mixture of BX2 and AX (where A is Cs). + Or Rb + Those skilled in the art can choose flexibly according to specific application scenarios.

[0077] For example, the organic salt solution can be AX (A is methylamino or formamidinyl), and AX can be one or more of the organic salts such as methyl ether hydroiodide, methyl ether hydrobromide, methylamine thiocyanate, and methylamine hydrochloride.

[0078] In one possible implementation, the thickness of the perovskite material layer can be the same as or comparable to that of the inorganic precursor layer. In this case, the inorganic precursor layer generally has a relatively loose structure with larger gaps between the inorganic precursor raw materials. Organic salts can enter these gaps, react with adjacent inorganic precursor raw materials, and form the perovskite material layer. Thus, the thickness of the resulting perovskite material layer is the same as or approximately comparable to that of the inorganic precursor layer. Alternatively, the thickness of the perovskite material layer can be greater than that of the inorganic precursor layer. In this case, the inorganic precursor layer has a relatively dense structure with smaller gaps between the inorganic precursor raw materials. Only a small amount or virtually no organic salts enter these gaps. The organic salts react with the underlying inorganic precursor raw materials to form the perovskite material layer, resulting in a perovskite material layer with a thickness greater than that of the inorganic precursor layer.

[0079] like Figure 3 and Figure 4 As shown, Figure 3 and Figure 4 The diagram shows a cross-sectional view of a perovskite layer structure formed on the surface of the first functional layer using the sequential deposition method described above. (See diagram for reference.) Figure 3As shown, the dark gray area at the bottom represents the substrate and the first functional layer. The surface of the substrate is textured, represented by wavy lines in the figure. The medium gray area above the textured surface represents the perovskite material layer. The light gray areas on the left and right sides of the medium gray area represent the non-overlapping regions 2, which are also the aforementioned inorganic precursor layers 3. It can be seen that the thickness of the perovskite material layer 1 is approximately the same as the thickness of the inorganic precursor layer 3 in the non-overlapping regions. Figure 3 The situation shown is similar to Figure 2 The difference is that the thickness of the perovskite material layer 1 is greater than the thickness of the inorganic precursor layer 3.

[0080] In one possible embodiment, the present invention also provides a perovskite solar cell, which includes the perovskite layer structure described in any of the foregoing embodiments or the perovskite layer structure prepared by any of the foregoing preparation methods.

[0081] like Figure 5 As shown, the perovskite solar cell includes, in sequence, an antireflection layer, a TCO layer, a SnO2 layer, a C60 layer, a perovskite layer (PVK layer), an HTL layer, an n-type amorphous silicon layer, a front intrinsic amorphous silicon layer, a silicon substrate, a back intrinsic amorphous silicon layer, a p-type amorphous silicon layer, an ITO layer, and Ag metal grid layers disposed at the top and bottom, respectively.

[0082] It should be noted that the perovskite solar cell can be a full cell or a half cell of a 210mm silicon wafer, or it can be an M6 size cell.

[0083] In one possible implementation, the present invention also provides a tandem battery comprising a bottom battery and a top battery arranged sequentially, wherein the bottom battery is a crystalline silicon battery and the top battery is the aforementioned perovskite solar cell.

[0084] It should be noted that the bottom cell can also be a III-V compound semiconductor cell, a full perovskite tandem cell, a copper indium gallium selenide cell, or a cadmium telluride cell, etc.

[0085] In one possible implementation, the present invention also provides a photovoltaic module comprising the aforementioned perovskite solar cell or tandem cell.

[0086] The following describes possible implementations of the present invention in conjunction with specific embodiments and comparative examples.

[0087] Example 1

[0088] A substrate is provided. The substrate is an N-type silicon wafer with a texture of 2μm and a wafer size of 210*105mm.

[0089] Fabrication of the bottom cell: Plasma-enhanced chemical vapor deposition (PECVD) was used to form a front-side amorphous silicon layer and a back-side amorphous silicon layer on the substrate. The front-side amorphous silicon layer includes a front-side intrinsic amorphous silicon layer and an n-type amorphous silicon layer, while the back-side amorphous silicon layer includes a back-side intrinsic amorphous silicon layer and a p-type amorphous silicon layer. The thicknesses of the front-side intrinsic amorphous silicon layer and the n-type amorphous silicon layer are 5 nm, 20 nm, 5 nm, and 30 nm respectively.

[0090] Preparation of ITO transparent conductive layer: ITO transparent conductive layer is formed on the surface of the bottom cell by sputtering, and the thickness of the transparent conductive layer is 8 nm.

[0091] Preparation of the first functional layer: A 0.5 mg / mL MeO-4PACz solution (ethanol as solvent) was inkjet printed onto the surface of the bottom cell with ITO deposited using a piezoelectric inkjet printer. The layer was then baked in an oven at 120°C for 10 min to obtain the SAM layer as the first functional layer. The thickness of the SAM layer is approximately 1 nm.

[0092] Preparation of perovskite material layers:

[0093] 1) Preparation of the inorganic precursor layer: Lead iodide and cesium bromide were loaded using a vacuum thermal evaporation method and placed together with the bottom cell having the SAM layer formed in a vacuum chamber. The chamber was then evacuated (≤5.0×10⁻⁶). -4 The material was heated to 100°C and the current of the two evaporation sources was slowly increased to evaporate the material. The rate ratio of lead iodide to cesium bromide was 3 Å / s: 0.5 Å / s. Lead iodide and cesium bromide were simultaneously deposited on the surface of the SAM layer, and the resulting inorganic precursor layer was 580 nm thick and covered the entire surface of the SAM layer.

[0094] 2) Preparation of the perovskite material layer: An organic salt solution was inkjet printed onto a predetermined area on the surface of the inorganic precursor layer using a piezoelectric inkjet printer. The predetermined area, measuring 209.6 x 104.6 mm, was located in the center of the inorganic precursor layer, with each of its four sides having a 0.2 mm distance from the corresponding side of the inorganic precursor layer. The organic salt solution was a mixture of dimethyl ether hydroiodide, dimethyl ether hydrobromide, methylamine thiocyanate, and methylamine hydrochloride, with isopropanol as the solvent. The concentrations of dimethyl ether hydroiodide, dimethyl ether hydrobromide, methylamine thiocyanate, and methylamine hydrochloride were 0.35 mol / L, 0.35 mol / L, 0.09 mol / L, and 0.09 mol / L, respectively. The mixture was then annealed in air at 30% humidity at 150°C for 20 minutes, resulting in a perovskite material layer with a thickness of 800 mm.

[0095] Preparation of passivation layer: Propane-1,3-diammonium diiodide (PDADI) was deposited on the surface of the perovskite material layer by thermal evaporation, and then annealed at 100°C for 2 min to form a passivation layer with a thickness of 2 nm.

[0096] Preparation of C60 layer: C60 layer with a thickness of 12 nm was prepared by thermal evaporation.

[0097] Preparation of SnO2 layer: SnO2 layer with a thickness of 15nm was formed by atomic layer deposition.

[0098] Preparation of IZO layer: IZO layer with a thickness of 50 nm was prepared by sputtering.

[0099] Preparation of Ag metal grid layers: The top and bottom Ag metal grid layers were prepared by printing.

[0100] Preparation of antireflection layer: A 110 nm thick MgF2 antireflection layer was prepared on top by thermal evaporation to complete the preparation of perovskite solar cells.

[0101] Example 2:

[0102] The difference from Example 1 is that the left side of the preset area coincides with the side corresponding to the substrate, the horizontal dimension between the right side and the side corresponding to the substrate is 0.2 mm, and the vertical dimension between the upper and lower long sides and the side corresponding to the substrate is 0.2 mm.

[0103] Example 3:

[0104] The difference from Example 1 is that the perovskite material layer is prepared in one step by inkjet printing. Specifically, the substrate has a texture of 1 μm. In preparing the perovskite material layer, CsI, FAI, PbI2, and PbBr2 are dissolved in a mixed solution of DMF:DMSO:NMP = 80:15:5 at a Pb concentration of 1.7 M. 60 mg / mL of methylammonium chloride (PbCl) is added, and the mixture is shaken for 6 hours to obtain a perovskite precursor solution. This solution is then filtered using a 0.22 μm filter to remove undissolved raw materials. The filtered perovskite precursor solution is then inkjet printed onto a predetermined area on the surface of the SAM layer. After annealing, the perovskite material layer is formed. The molecular formula of this perovskite material layer is CsI. 0.25 FA 0.75 Pb(I 0.8 Br 0.23. The thickness of this perovskite material layer is approximately 2 μm. It should be noted that this thickness refers to the thickness of the perovskite material layer from the bottom of the pyramidal textured surface of the silicon wafer to the surface of the perovskite material layer. The preset area for inkjet printing has dimensions of 209.6 * 104.6 mm, located in the center of the SAM layer. The horizontal dimensions between its left and right sides and the corresponding sides of the SAM layer, and the vertical dimensions between its top and bottom sides and the corresponding sides of the SAM layer, are both 0.2 mm.

[0105] Comparative Example 1:

[0106] The difference from Example 1 is that the size of the preset area is slightly larger than the size of the substrate, 211*106 mm, so that the inkjet printing area can completely cover the surface of the SAM layer.

[0107] Comparative Example 2:

[0108] The difference from Example 3 is that the size of the preset area for inkjet printing is 211*106 mm, so that the inkjet printing range can completely cover the surface of the SAM layer.

[0109] The photovoltaic performance parameters of the perovskite solar cells prepared in the above embodiments and comparative examples were tested, and the test results are shown in Table 1 below.

[0110] The main photovoltaic performance parameters include short-circuit current, open-circuit voltage, fill factor, and photoelectric conversion efficiency. The test methods for these performance parameters are as follows:

[0111] The battery was placed in a light source with a spectrum of AM 1.5G and an illuminance of 100 mW / cm². 2 Under simulated sunlight at a temperature of 25°C, voltage scanning was performed using a four-wire connection to a source meter, with corresponding current values ​​recorded simultaneously to obtain a current-voltage (IV) curve. From this current-voltage (IV) curve, the short-circuit current, open-circuit voltage, fill factor, and photoelectric conversion efficiency can be directly obtained.

[0112] Table 1 <![CDATA[Short-circuit current mA / cm 2 > Open circuit voltage V Fill factor % Photoelectric conversion efficiency % Example 1 19.56 1.943 80.21 30.48 Example 2 19.55 1.938 79.89 30.27 Example 3 19.42 1.997 82.32 31.93 Comparative Example 1 19.55 1.928 78.45 29.57 Comparative Example 2 19.42 1.981 81.22 31.24

[0113] As can be seen from Table 1 above, by ensuring that the perovskite material layer and the first functional layer have a non-overlapping region in their orthogonal projections on the horizontal plane, the solar cell containing this perovskite layer structure significantly improves the open-circuit voltage, fill factor, and photoelectric conversion efficiency compared to a solar cell where the perovskite material layer covers the entire first functional layer. Specifically, the open-circuit voltage can be increased by 0.8%, the fill factor by 2.2%, and the photoelectric conversion efficiency by 3.1%, effectively enhancing the photovoltaic performance of perovskite solar cells.

[0114] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A perovskite layer structure, characterized in that, include: Base; A first functional layer is disposed on the substrate; a perovskite material layer is disposed on the first functional layer; wherein the perovskite material layer and the first functional layer have a non-overlapping region in their orthogonal projections on a horizontal plane.

2. The perovskite layer structure according to claim 1, characterized in that, The non-overlapping region is the exposed surface of the first functional layer that is not covered by the perovskite material layer.

3. The perovskite layer structure according to claim 2, characterized in that, The exposed surface forms a closed ring around the perovskite material layer.

4. The perovskite layer structure according to claim 2, characterized in that, The exposed surfaces are located only on opposite sides of the perovskite material layer.

5. The perovskite layer structure according to any one of claims 1-4, characterized in that, The maximum dimension L of the non-overlapping region in the direction parallel to the base plane satisfies: 0 < L ≤ 0.2 mm.

6. A method for preparing a perovskite layer structure, characterized in that, include: Provide a base; A first functional layer is formed on the substrate; By spatially selectively depositing, a perovskite material layer is formed on a portion of the surface of the first functional layer, such that the perovskite material layer and the orthographic projection of the first functional layer on the horizontal plane have a non-overlapping region.

7. The preparation method according to claim 6, characterized in that, The spatial selective deposition is a patterned solution method, in which a perovskite precursor solution is directly coated onto the surface of the portion, and a perovskite material layer is formed by heat treatment.

8. The preparation method according to claim 6, characterized in that, The spatial selective deposition is a vapor deposition method, in which the component materials constituting the perovskite are deposited in vapor form on the surface of the part, and then heat-treated to form a perovskite material layer.

9. The preparation method according to claim 6, characterized in that, The spatially selective deposition is a sequential deposition method, which includes: first forming an inorganic precursor layer on the first functional layer; then applying an organic salt solution to at least a portion of the surface of the inorganic precursor layer to react and generate a perovskite material layer.

10. A perovskite solar cell, characterized in that, The perovskite solar cell comprises the perovskite layer structure according to any one of claims 1-5 or the perovskite layer structure prepared by the preparation method according to any one of claims 6-9.

11. A stacked battery, characterized in that, The stacked cell comprises a bottom cell and a top cell arranged in sequence, wherein the top cell is the perovskite solar cell according to claim 10.

12. The stacked battery according to claim 11, characterized in that, The bottom battery is a crystalline silicon battery.

13. A photovoltaic module, characterized in that, The photovoltaic module includes the perovskite solar cell of claim 10 or the tandem cell of claim 11 or 12.

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