Method for manufacturing perovskite cell and perovskite cell

Abstract

This application provides a method for fabricating a perovskite solar cell and a perovskite solar cell. The method for fabricating the perovskite solar cell includes forming a first charge transport layer on a glass substrate; coating a perovskite precursor solution onto the first charge transport layer to form a perovskite precursor liquid film on the first charge transport layer; subjecting the perovskite precursor liquid film to a shaping treatment and a heat treatment in sequence to transform the perovskite precursor liquid film into a perovskite layer, wherein, during the heat treatment, the distance between the middle region of the glass substrate and the heating unit is greater than the distance between the peripheral region and the heating unit, so that the perovskite precursor liquid film after the shaping treatment is heated uniformly; and performing a planarization treatment on the perovskite layer.

Description

Technical Field

[0001] This application mainly relates to the field of photovoltaic technology, and in particular to a method for preparing a perovskite cell and the perovskite cell itself. Background Technology

[0002] In the field of solar cells, perovskite solar cells have attracted much attention due to their excellent photoelectric performance, high photoelectric conversion efficiency, low fabrication cost, and simple process. However, the efficiency and stability of the perovskite layer are poor under the long-term effects of water, oxygen, light, and heat, leading to a reduction in the lifespan of perovskite solar cells.

[0003] Existing technologies typically employ an anti-solvent method to prepare high-quality perovskite layers, combined with perovskite passivation strategies to reduce defects in the perovskite bulk phase and interfaces, thereby decreasing non-radiative recombination of charge carriers in perovskite solar cells. However, this preparation method and passivation strategy still have problems. On the one hand, the anti-solvent method is not conducive to the preparation of large-area perovskite solar cells and easily leads to problems such as poor perovskite film quality and numerous defects. On the other hand, when preparing large-area perovskite films, the temperature uniformity of the heat treatment equipment itself affects the crystallization quality and uniformity of the perovskite film. For example, when using a hot stage to prepare large-area perovskite films, contact between the glass substrate and the hot stage causes warping at the glass edges, resulting in large differences in the annealing temperature of the perovskite film, leading to abnormal and uneven crystallization. Similarly, when using an oven to prepare large-area perovskite films, temperature differences exist between the central and peripheral areas of the oven, also resulting in abnormal and uneven crystallization of the perovskite film.

[0004] Therefore, there is an urgent need in this field for a method for preparing perovskite solar cells and for perovskite solar cells in order to solve the above problems. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide a method for preparing a perovskite solar cell and a perovskite solar cell. The preparation method can improve the heating uniformity of the liquid film of the perovskite precursor after shaping treatment, thereby improving the crystallization quality and crystallization uniformity of the prepared perovskite layer.

[0006] To address the aforementioned technical problems, this application provides a method for fabricating a perovskite solar cell. The method includes: forming a first charge transport layer on a glass substrate; coating a perovskite precursor solution onto the first charge transport layer to form a perovskite precursor liquid film on the first charge transport layer; sequentially subjecting the perovskite precursor liquid film to a shaping treatment and a heat treatment to transform the perovskite precursor liquid film into a perovskite layer, wherein, during the heat treatment, the distance between the central region of the glass substrate and the heating unit is greater than the distance between the peripheral region and the heating unit, so that the perovskite precursor liquid film after the shaping treatment is heated uniformly; and performing a planarization treatment on the perovskite layer.

[0007] In one embodiment of this application, the heating unit includes a first heating plate, and the heat treatment is performed using the first heating plate. In this embodiment, a pin is used to lift the glass substrate above the first heating plate, and the length of the pin lifting the middle region is greater than the length of the pin lifting the peripheral region.

[0008] In one embodiment of this application, the heating unit includes a second heating plate and a plurality of first transmission rollers located on the second heating plate for transporting perovskite battery intermediates. The heat treatment is performed using the second heating plate and the plurality of first transmission rollers, wherein the glass substrate is in contact with the plurality of first transmission rollers, and in the axial direction of each first transmission roller, the diameter of the middle section of the first transmission roller is greater than the diameter of both ends.

[0009] In one embodiment of this application, the heating unit includes a third heating plate and a plurality of second transmission rollers located on the third heating plate for transporting perovskite battery intermediates. The heat treatment is performed using the third heating plate and the plurality of second transmission rollers, wherein the intermediate region is supported by the plurality of second transmission rollers and the peripheral region is suspended.

[0010] In one embodiment of this application, the difference in distance between the central region, the peripheral region and the heating unit is not less than 0.5 cm.

[0011] In one embodiment of this application, the method further includes: forming a second charge transport layer on the perovskite layer, wherein the glass substrate is in an arched state during the formation of the second charge transport layer.

[0012] In one embodiment of this application, the glass substrate is supported on opposite sides by a carrier plate to place the glass substrate in the arched state.

[0013] In one embodiment of this application, the shaping process includes a vacuum flash evaporation process.

[0014] In one embodiment of this application, the heating temperature of the heat treatment is 100°C to 160°C.

[0015] This application also provides a perovskite solar cell, comprising a glass layer, a transparent conductive layer, a first charge transport layer, a perovskite layer, a second charge transport layer, and a back electrode stacked sequentially, wherein the perovskite solar cell is prepared by the perovskite solar cell preparation method described above.

[0016] Compared with the prior art, this application has the following advantages: (1) By making the distance between the middle region of the glass substrate and the heating unit greater than the distance between the peripheral region and the heating unit, the problem of uneven thermal field during heat treatment is improved, the temperature uniformity of the entire glass substrate is enhanced, and the perovskite precursor liquid film after shaping treatment is heated uniformly. By making the perovskite precursor liquid film after shaping treatment heated uniformly during heat treatment, the crystal quality and crystal uniformity of the final perovskite layer can be improved. (2) By using the difference in spacing between the middle area and the periphery of the glass substrate and the heating unit, as well as the weight of the glass substrate itself, the glass substrate is made to be in an arched state during the preparation of the perovskite layer. After the preparation is completed, the perovskite layer is flattened. In this way, the compressive stress inside the perovskite layer is further increased, thereby improving the quality of the perovskite layer. Attached Figure Description

[0017] The accompanying drawings are included to provide a further understanding of this application; they are incorporated into and constitute a part of this application. The drawings illustrate embodiments of this application and, together with this specification, serve to explain the principles of this application. In the drawings: Figure 1 This is a schematic flowchart of a method for preparing a perovskite solar cell according to an embodiment of this application; Figure 2 This is a cross-sectional schematic diagram of a heat treatment apparatus according to an embodiment of this application; Figure 3 This is a cross-sectional schematic diagram of a proportional heat treatment apparatus of this application; Figure 4 This is a schematic diagram of the structure of a perovskite solar cell according to an embodiment of this application.

[0018] Reference numerals: Oven 100, First heating plate 110, Glass substrate 120, Ejector pin 130, Fourth heating plate 140, Oven 200, Lower heating plate 210, Glass substrate 220, Ejector pin 230, Upper heating plate 240, Perovskite cell 300, Glass layer 310, Transparent conductive layer 320, First charge transport layer 330, Perovskite layer 340, Second charge transport layer 350, Back electrode 360, P1 scribe line 381, P2 scribe line 382, ​​P3 scribe line 383, Lead wire 370. Detailed Implementation

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0020] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0021] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0022] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0023] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0024] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0025] It should be understood that when a component is referred to as "on another component," "connected to another component," "coupled to another component," or "in contact with another component," it can be directly on, connected to, coupled to, or in contact with that other component, or there may be an intervening component. In contrast, when a component is referred to as "directly on another component," "directly connected to," "directly coupled to," or "directly in contact with" another component, there is no intervening component. Similarly, when a first component is referred to as "electrically contacting" or "electrically coupled to" a second component, there is an electrical path between the first and second components that allows current to flow. This electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even if there is no direct contact between the conductive components.

[0026] Flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, various steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from these processes.

[0027] The preparation method and the perovskite battery of this application will be described below through specific embodiments.

[0028] A perovskite solar cell comprises a glass layer, a transparent conductive layer, a first charge transport layer, a perovskite layer, a second charge transport layer, and a back electrode, stacked sequentially. The fabrication method of this application can fabricate both conventional and inverted perovskite solar cells. In a conventional perovskite solar cell, the first charge transport layer is an electron transport layer, and the second charge transport layer is a hole transport layer. In an inverted perovskite solar cell, the first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer.

[0029] refer to Figure 1 The perovskite solar cell in one embodiment shown is prepared by a method (hereinafter referred to as the "preparation method"), which includes the following steps.

[0030] Step S110: A first charge transport layer is formed on the glass substrate.

[0031] Specifically, the glass substrate includes a glass layer and a transparent conductive layer located on the glass layer. A first charge transport layer can be formed on the transparent conductive layer by a slit coating method. The material of the transparent conductive layer can include a transparent conductive oxide (TCO), which can be selected from one or more of indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), indium zinc oxide (IZO), and tungsten-doped indium oxide (IWO).

[0032] In some embodiments, the first charge transport layer is an electron transport layer (ETL), the material of which includes isomethyl [6,6]-phenyl-C71-butyrate (PCBM), C 60 And Indene-C 60 One or more of the diadducts (abbreviated as ICBA).

[0033] In some embodiments, the first charge transport layer is a hole transport layer (HTL), and its material includes organic hole transport materials, inorganic hole transport materials, self-assembled monolayer (SAM) materials, and poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), etc. The self-assembled monolayer materials include one or more of the following: [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (abbreviated as 2PACZ), (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid (abbreviated as MeO-2PACZ), (4-(3,6-dimethyl-9H-carbazole-9-yl)ethyl)phosphonic acid (abbreviated as Me-4PACZ), (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanotitanium)phosphonic acid (abbreviated as MPA-CPA), and (4-(2,7-dibromo-9,9-dimethylacridin-10(9H)yl)butyl)phosphonic acid (abbreviated as DMAcPA).

[0034] As an example of step S110, firstly, a nickel oxide (NiOx) layer with a thickness of 20 nm is prepared on a glass substrate with P1 lines etched using a magnetron sputtering process; subsequently, a Me-4PACZ layer is prepared on the nickel oxide layer using a slot coating process, and then annealed to obtain a solid film. Thus, a first charge transport layer comprising the nickel oxide layer and the Me-4PACZ layer is formed.

[0035] Step S120: A perovskite precursor solution is coated on the first charge transport layer to form a perovskite precursor liquid film on the first charge transport layer.

[0036] Specifically, the perovskite precursor and solvent are mixed and fully dissolved in a certain proportion to ensure the uniformity of the solution and good coating performance. The prepared perovskite precursor solution is then uniformly coated onto the pre-prepared first charge transport layer, typically using spin coating technology. During spin coating, the solution is dropped onto the first charge transport layer and uniformly distributed by high-speed rotation, thereby forming a uniform liquid film on the first charge transport layer. This liquid film is the perovskite precursor liquid film.

[0037] In some embodiments, formamidinium iodide (FAI), lead iodide (PbI2), methylamine chloride (MACl), methylamine iodide (MAI), and cesium iodide (CsI) powders are mixed and dissolved in a solvent to obtain a solution containing CsI. 0.05 FA 0.9 MA 0.05 A perovskite precursor solution of PbI3. For example, the solvent is a mixture of N,N-dimethylformamide (DMF) and dimethylpyrrolidone (NMP), wherein the volume ratio of DMF to NMP is 9:1.

[0038] Step S130: The perovskite precursor liquid film is subjected to shaping and heat treatment in sequence to transform the perovskite precursor liquid film into a perovskite layer. During the heat treatment, the distance between the middle region of the glass substrate and the heating unit is greater than the distance between the peripheral region and the heating unit, so that the perovskite precursor liquid film after shaping is heated uniformly.

[0039] Specifically, the perovskite precursor liquid film undergoes a stabilization process under certain conditions. During this process, the solvent in the perovskite precursor liquid film gradually evaporates, and the surface of the film begins to dry. However, the solvent in the inner layer has not completely evaporated, allowing the film to maintain a certain degree of fluidity, thus laying the foundation for subsequent heat treatment. During the stabilization process, temperature and humidity are controlled to promote the initial stabilization of the liquid film while preventing excessively rapid solvent evaporation or uneven film formation.

[0040] The shaped perovskite precursor liquid film will then undergo a heat treatment stage. During this stage, the solvent in the perovskite precursor liquid film will further evaporate, the structure of the liquid film will gradually stabilize, and a series of physical and chemical changes will occur. In the heat treatment process, the perovskite precursor liquid film successively undergoes solvent evaporation, nucleation, crystal growth, morphology optimization, and densification, thus transforming into a solid perovskite layer.

[0041] In some embodiments, the shaping process includes vacuum flash evaporation of the perovskite precursor liquid film. Vacuum flash evaporation can instantly vaporize and remove the surface solvent of the perovskite precursor liquid film in a vacuum environment, so as to quickly shape the perovskite precursor liquid film and avoid problems such as film sagging and uneven film thickness caused by glass substrate shaking and uneven surface tension.

[0042] In some embodiments, the heating temperature for heat treatment is 100°C to 160°C, for example, 100°C, 120°C, 140°C and 160°C.

[0043] The heating unit for heat treatment includes a first heating plate, through which the shaped perovskite precursor liquid film is heat-treated. To ensure that the distance between the central region of the glass substrate and the heating unit is greater than the distance between the peripheral region and the heating unit, ejector pins of varying lengths are used to lift the glass substrate above the first heating plate. Specifically, the length of the ejector pin lifting the central region of the glass substrate is greater than the length of the ejector pin lifting the peripheral region. Thus, during heat treatment, due to the difference in weight of the glass substrate and the length of the ejector pins, the central region of the cross-section along the thickness direction of the glass substrate protrudes beyond the peripheral region, resulting in an arched shape for the glass substrate. This causes the central region of the glass substrate to be farther from the first heating plate, while the peripheral region is closer to the first heating plate, which matches the conventional design of the heating temperature of the first heating plate (i.e., the temperature of the central region of the first heating plate is slightly higher than that of the peripheral region), thereby improving the temperature uniformity of the entire glass substrate. Furthermore, during heat treatment, the temperature uniformity of the glass substrate can improve the crystallinity and uniformity of the final formed perovskite layer.

[0044] refer to Figure 2 A cross-sectional schematic diagram of a heat treatment apparatus according to an embodiment is shown, using an oven 100 ( Figure 2 (Only a partial structure of oven 100 is shown) The oven 100 heat-treats the shaped perovskite precursor liquid film. Oven 100 includes a first heating plate 110 and a fourth heating plate 140. Pins 130 of varying lengths are disposed on the surface of the first heating plate 110 facing the fourth heating plate 140. A glass substrate 120 is located between the first heating plate 110 and the fourth heating plate 140 and is supported by the pins 130. It is understood that a first charge transport layer and the shaped perovskite precursor liquid film are sequentially formed on the surface of the glass substrate 120 away from the pins 130.

[0045] like Figure 2 As shown, the length of the ejector pin 130 that lifts the middle region of the glass substrate 120 is greater than the length of the ejector pin 130 that lifts the peripheral region of the glass substrate 120. Due to the weight of the glass substrate 120 itself and the difference in length between the ejector pins 130, the glass substrate 120 is in an arched state. Thus, the distance between the middle region of the glass substrate 120 and the first heating plate 110 is greater than the distance between the peripheral region of the glass substrate 120 and the first heating plate 110, thereby improving the temperature uniformity of the entire glass substrate 120.

[0046] refer to Figure 3 The diagram shows a cross-sectional view of an apparatus for a heat treatment process in proportion to a 200 oven. Figure 3(Only a partial structure of oven 200 is shown) The oven processes the shaped perovskite precursor liquid film. Oven 200 includes a lower heating plate 210, an upper heating plate 240, and a glass substrate 220 located between the upper and lower heating plates. The surface of the lower heating plate 210 facing the upper heating plate 240 is provided with ejector pins 230 of uniform length. The glass substrate 220 is lifted by the ejector pins 230 of uniform length on the lower heating plate 210, thereby keeping the glass substrate 220 flat during heat treatment. Thus, in... Figure 3 In the comparative example shown, due to the temperature differences inside the oven 200, the temperature difference between the central and peripheral regions of the glass substrate 220 is large, resulting in abnormal and uneven crystallization of the final perovskite layer. Simultaneously, under thermal stress, the peripheral region of the glass substrate 220 warps, further contributing to the temperature differences in the heat treatment of the entire glass substrate 220.

[0047] Compared to Figure 3 As shown in the comparative examples, the technical solution of this application enables the perovskite precursor liquid film after shaping treatment to be heated uniformly, thereby improving the problems of abnormal and uneven crystallization of the perovskite layer caused by uneven heating in related technologies.

[0048] In some embodiments, the heating unit for heat treatment includes a second heating plate and a plurality of first drive rollers located on the second heating plate for transferring a perovskite battery intermediate (after shaping). During the heat treatment process, the glass substrate of the perovskite intermediate comes into contact with the plurality of first drive rollers, which carry and transfer the perovskite battery intermediate. The perovskite battery intermediate is heat-treated using the second heating plate and the plurality of first drive rollers.

[0049] Compared to the cylindrical drive rollers of equal diameter in related technologies, in this embodiment, the diameter of the middle section of each first drive roller in the axial direction is larger than the diameter of both ends. As a result, the glass substrate is in an arched state under the action of the first drive roller and its own weight, and the distance between the middle area of ​​the glass substrate and the second heating plate is greater than the distance between the peripheral area and the second heating plate, thereby making the perovskite battery intermediate uniformly heated.

[0050] In some embodiments, the heating unit for heat treatment includes a third heating plate and a plurality of second drive rollers located on the third heating plate for transporting the perovskite battery intermediate. The plurality of second drive rollers only contact and support the central region of the glass substrate, while the peripheral region of the glass substrate is suspended. In related technologies, drive rollers are mostly cylindrical with a uniform diameter and simultaneously support both the central and peripheral regions of the glass substrate. Compared to related technologies, the second drive rollers in this application only support the central region of the glass substrate. Thus, the glass substrate is in an arched state under its own gravity, and the distance between the central region of the glass substrate and the third heating plate is greater than the distance between the peripheral region and the third heating plate, thereby ensuring uniform heating of the perovskite battery intermediate.

[0051] For example, the contact width between the second drive roller and the middle region of the glass substrate is one-third of the width of the glass substrate.

[0052] During the heat treatment process, the perovskite cell intermediate is carried and transported by multiple second drive rollers, and the perovskite cell intermediate is heat-treated by a third heating plate.

[0053] In some embodiments, the difference between the distance between the middle region of the glass substrate and the heating unit and the distance between the peripheral region of the glass substrate and the heating unit is not less than 0.5 cm.

[0054] Step S140: The perovskite layer is leveled.

[0055] In this step, the glass substrate, which was in an arched state during the heat treatment in step S130, is flattened to restore the glass substrate and the perovskite layer formed on it to a flat state. The deformation of the glass substrate from an arched state to a flat state increases the compressive stress inside the perovskite layer, promoting densification, strengthening grain boundary bonding, reducing grain boundary defects, and improving grain boundary integrity. This improves the quality of the prepared perovskite layer, thereby enhancing the efficiency and stability of the perovskite solar cell.

[0056] It should be noted that, based on steps S110 to S140 described above, the fabrication method further includes sequentially forming a second charge transport layer and a back electrode on the perovskite layer, and scribing lines from P1 to P3 using a laser to obtain the perovskite solar cell product. These steps are not the focus of this application and will not be elaborated upon.

[0057] In some embodiments, the fabrication method further includes forming a second charge transport layer on the perovskite layer while the glass substrate is in an arched state. In a perovskite solar cell with a formal structure, the second charge transport layer is a hole transport layer; in a perovskite solar cell with an inverted structure, the second charge transport layer is an electron transport layer.

[0058] As an example, during the formation of the second charge transport layer, a carrier plate supports the glass substrate on opposite sides to create an arched shape. In this case, the surface of the glass substrate furthest from the perovskite layer faces upwards, and the substrate bends downwards under gravity, exacerbating the arching. In some embodiments, because the torque on the longer side is greater than that on the shorter side, the carrier plate supports the shorter sides of the glass substrate to achieve greater deformation, further intensifying the arching.

[0059] It should be noted that this application does not limit the number of planarization processes or whether planarization is performed before forming the second charge transport layer. For example, planarization may be performed after forming the second charge transport layer, or both before and after forming the second charge transport layer. Therefore, any method for preparing a perovskite solar cell in a planar state is within the scope of protection of this application.

[0060] In some embodiments, the back electrode includes a metal electrode or a metal oxide transparent electrode, wherein the material of the metal electrode includes one or more of Ag, Au, and Cu, and the material of the metal oxide transparent electrode includes one or more of ITO, IZO, AZO, and IWO.

[0061] Furthermore, this application also proposes a perovskite solar cell prepared by the preparation method described above. (Reference) Figure 4 The schematic diagram of a perovskite solar cell according to an embodiment is shown. The perovskite solar cell 300 includes a glass layer 310, a transparent conductive layer 320, a first charge transport layer 330, a perovskite layer 340, a second charge transport layer 350, and a back electrode 360, which are stacked sequentially. Line P1 381 is formed after the transparent conductive layer 320 is prepared, and is evenly distributed throughout the transparent conductive layer 320, penetrating the transparent conductive layer 320. Line P2 382 is formed after the second charge transport layer 350 is prepared, located to the right of line P1 381, and penetrates the first charge transport layer 330, the perovskite layer 340, and the second charge transport layer 350. Line P3 383 is formed after the back electrode 360 ​​is prepared, located to the right of line P2 382, ​​and penetrates the perovskite layer 340, the second charge transport layer 350, and the back electrode 360.

[0062] In this process, the perovskite layer 340 is prepared through steps S120 to S140. During the heat treatment, because the distance between the central region of the glass layer 310 and the heating unit is greater than the distance between the peripheral region and the heating unit, the perovskite layer 340 is heated uniformly, thereby improving the crystallization quality and uniformity. Furthermore, during the flattening process, the glass layer 310 is restored from an arched state to a flat state, compressing the perovskite layer 340 and increasing the compressive stress, thereby improving the quality of the perovskite layer 340 and further enhancing the efficiency and stability of the perovskite solar cell 300.

[0063] Based on the preparation method described above, the electrical performance of the technical solution of this application is further verified through the following specific non-limiting examples and comparative examples.

[0064] Example 1

[0065] The preparation method of this embodiment includes steps S1 to S10. In step S1, FAI, PbI2, MACl, MAI, and CsI powders are mixed and added to 1 ml of solvent for dissolution. The solvent is a mixture of DMF and NMP, wherein DMF:NMP = 9:1, to obtain CsI. 0.05 FA 0.9 MA 0.05 A PbI3 perovskite precursor solution was prepared, and the hole transport layer material Me-4PACZ was dissolved in ethanol at a concentration of 1 mg / mL.

[0066] In step S2, the 600nm×1200nm FTO transparent conductive glass is cleaned and dried with nitrogen gas.

[0067] In step S3, a 1064nm laser is used to scribing P1 lines on the FTO transparent conductive layer to form equally spaced P1 line grooves that penetrate the FTO transparent conductive layer, with a width of 20μm.

[0068] In step S4, a 20 nm NiOx layer is prepared on the FTO transparent conductive layer after the P1 groove is scribed by magnetron sputtering. Then, a Me-4PACZ layer is prepared by slit coating and annealing to obtain a solid film. NiOx and Me-4PACZ together form a hole transport layer.

[0069] In step S5, a perovskite precursor solution is slit-coated onto the hole transport layer to obtain a uniform liquid film. This film is then processed using a VCD and followed by annealing to obtain the perovskite layer. During the annealing process, the glass substrate is placed as follows: Figure 2 In the oven 100 shown, ejector pins 130 lift the glass substrate above the first heating plate 110. The length of the ejector pins 130 lifting the middle region of the glass substrate is greater than the length of the ejector pins 130 lifting the peripheral region of the glass substrate, such that the distance between the middle region and the first heating plate 110 is greater than the distance between the peripheral region and the first heating plate 110. Specifically, the distance between the center of the glass substrate and the first heating plate 110 is 20 mm, and the distance between the edge of the glass substrate and the first heating plate is 18 mm.

[0070] In step S6, a 20 nm C layer is deposited on the perovskite layer by vapor deposition. 60In the vapor deposition process, the glass substrate is placed on a carrier plate with the surface of the glass substrate furthest from the perovskite layer facing upwards. The carrier plate contacts and supports the shorter, opposite sides of the glass substrate, causing the glass substrate to bend downwards under gravity. After vapor deposition is complete, the glass substrate is flattened and placed in an ALD (Alternating Discharge) device to prepare a 20nm SnO2 layer as an electron transport layer.

[0071] In step S7, a 532nm laser is used to scribing a P2 line, forming a P2 line groove that runs through the hole transport layer, the perovskite layer, and the electron transport layer. The P2 line groove is 50μm wide, located to the right of the P1 line groove, and is 20μm away from the P1 line groove.

[0072] In step S8, a composite layer of 30 nm ITO, 100 nm Cu and 50 nm ITO is prepared sequentially by magnetron sputtering as the back electrode.

[0073] In step S9, a 532nm laser is used to scribing P3 lines to form a P3 groove that runs through the perovskite layer, the electron transport layer, and the back electrode. The groove is 150μm wide, located to the right of the P2 groove, and 50μm away from the P2 groove.

[0074] In step S10, edge cleaning is performed and leads are connected to prepare a perovskite solar cell.

[0075] Example 2

[0076] The preparation method of this embodiment includes steps S1 to S10. Except for setting the distance between the center of the glass substrate and the first heating plate 110 to 12 mm and the distance between the edge of the glass substrate and the first heating plate to 10 mm in step S5, the other preparation steps are the same as in embodiment one, thereby preparing a perovskite solar cell.

[0077] Comparative Example 1

[0078] The difference between this comparative example and Example 1 is that, during the annealing process in step S5, the glass substrate is placed in an oven, and a flat carrier plate is used to fully contact the glass substrate to support it. In other words, the distance between the central region of the glass substrate and the heating unit is equal to the distance between the peripheral region of the glass substrate and the heating unit. All other preparation steps are the same as in Example 1, thus obtaining a perovskite solar cell.

[0079] The electrical performance parameters of the perovskite solar cells prepared by the methods of Example 1, Example 2, and Comparative Example 1 are recorded in Table 1. The electrical performance parameters include open-circuit voltage (Voc, in V) and short-circuit current density (Jsc, in mA / cm²). 2The fill factor (FF) and photoelectric conversion efficiency (Eff) of this application are also considered. In Examples 1 and 2, the short-circuit current density, fill factor, and photoelectric conversion efficiency for both forward and reverse scans are higher than those of Comparative Example 1, indicating that the technical solution of this application is beneficial for improving the efficiency of perovskite solar cells.

[0080] Table 1: Electrical performance parameters of perovskite solar cells.

[0081]

[0082] The basic concepts have been described above. Obviously, for those skilled in the art, the above disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0083] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0084] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the present application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0085] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of scope in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0086] Although this application has been described with reference to specific embodiments, those skilled in the art should recognize that the above embodiments are only used to illustrate this application, and various equivalent changes or substitutions can be made without departing from the spirit of this application. Therefore, any changes or modifications to the above embodiments within the essential spirit of this application will fall within the scope of the claims of this application.

Claims

1. A method for preparing a perovskite solar cell, characterized in that, include: A first charge transport layer is formed on a glass substrate; A perovskite precursor solution is coated on the first charge transport layer to form a perovskite precursor liquid film on the first charge transport layer. The perovskite precursor liquid film is subjected to shaping and heat treatment in sequence to transform the perovskite precursor liquid film into a perovskite layer. During the heat treatment, the distance between the middle region of the glass substrate and the heating unit is greater than the distance between the peripheral region and the heating unit, so that the perovskite precursor liquid film after the shaping treatment is heated uniformly. as well as The perovskite layer is then leveled.

2. The method for preparing a perovskite solar cell as described in claim 1, characterized in that, The heating unit includes a first heating plate, and the heat treatment is performed using the first heating plate. The glass substrate is lifted above the first heating plate using a push pin, and the length of the push pin lifting the middle region is greater than the length of the push pin lifting the peripheral region.

3. The method for preparing a perovskite solar cell as described in claim 1, characterized in that, The heating unit includes a second heating plate and a plurality of first transmission rollers located on the second heating plate for transporting perovskite cell intermediates. The heat treatment is performed using the second heating plate and the plurality of first transmission rollers, wherein the glass substrate is in contact with the plurality of first transmission rollers, and in the axial direction of each first transmission roller, the diameter of the middle section of the first transmission roller is greater than the diameter of the two ends.

4. The method for preparing a perovskite solar cell as described in claim 1, characterized in that, The heating unit includes a third heating plate and a plurality of second transmission rollers located on the third heating plate for transporting the perovskite cell intermediate. The heat treatment is performed using the third heating plate and the plurality of second transmission rollers, wherein the intermediate region is supported by the plurality of second transmission rollers and the peripheral region is suspended.

5. The method for preparing a perovskite solar cell according to any one of claims 1 to 4, characterized in that, The difference in distance between the central region, the peripheral region and the heating unit is not less than 0.5 cm.

6. The method for preparing a perovskite solar cell as described in claim 1, characterized in that, Also includes: A second charge transport layer is formed on the perovskite layer, wherein the glass substrate is in an arched state during the formation of the second charge transport layer.

7. The method for preparing a perovskite solar cell as described in claim 6, characterized in that, The glass substrate is supported on opposite sides by a carrier plate to place the glass substrate in the arched state.

8. The method for preparing a perovskite solar cell as described in claim 1, characterized in that, The shaping process includes vacuum flash evaporation.

9. The method for preparing a perovskite solar cell as described in claim 1, characterized in that, The heating temperature for the heat treatment is 100℃~160℃.

10. A perovskite solar cell, characterized in that, The perovskite battery comprises a glass layer, a transparent conductive layer, a first charge transport layer, a perovskite layer, a second charge transport layer, and a back electrode, which are stacked sequentially. The perovskite battery is prepared by the method for preparing a perovskite battery as described in any one of claims 1-9.

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