Perovskite solar cell and preparation method thereof

Abstract

The invention relates to the technical field of solar cells, in particular to a perovskite solar cell and a preparation method thereof. The perovskite solar cell comprises a hole transport layer, an interface modification layer and a perovskite photoactive layer which are stacked, wherein the hole transport layer comprises a self-assembly monomolecular layer; the interface modification layer comprises an organic additive, and the organic additive comprises R1 and R2; r1 is a carboxylic acid group, and R2 is an amino group. And iminodiacetic acid. According to the embodiment of the invention, the interface modification layer containing the organic additive is introduced, so that the distribution of the perovskite light active layer is more uniform, and meanwhile, due to the existence of the interface modification layer, the defects on the interface of the interface modification layer / the perovskite light active layer are fewer. The efficiency of the perovskite solar cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a perovskite solar cell and a preparation method thereof. Background Art

[0002] Pin-type single-junction perovskite solar cells (PSCs), also known as inverted perovskite solar cells, have the characteristics of high conversion efficiency, good stability and easy manufacturing. In inverted perovskite solar cells, the hole transport layer (HTL) can include a self-assembled monolayer, which has excellent electron blocking and hole selection properties. However, the use of the self-assembled monolayer as a hole transport layer has the problem of poor wettability to the perovskite precursor solution, resulting in uneven distribution of the perovskite photoactive layer, which limits the further improvement of the performance of perovskite solar cells.

[0003] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0004] The embodiments of the present application provide a perovskite solar cell and a method for preparing the same to solve or alleviate one or more of the technical problems raised above.

[0005] A first aspect of an embodiment of the present application provides a perovskite solar cell.

[0006] The perovskite solar cell comprises: a hole transport layer, an interface modification layer and a perovskite photoactive layer are stacked; Wherein, the hole transport layer comprises a self-assembled monolayer; The interface modification layer includes an organic additive, and the organic additive has an R1 group and an R2 group; R1 is a carboxylic acid group, and R2 is an amino group.

[0007] In the first aspect of the embodiment of the present application, by introducing an interface modification layer including an organic additive, the distribution of the perovskite photoactive layer is made more uniform, and at the same time, the presence of the interface modification layer makes the interface of the interface modification layer / perovskite photoactive layer have fewer defects. The efficiency of the perovskite solar cell is improved.

[0008] A second aspect of an embodiment of the present application provides a method for preparing a perovskite solar cell.

[0009] The method for preparing the perovskite solar cell comprises the following operations: Providing a transparent conductive substrate, on which a hole transport layer and an interface modification layer are sequentially stacked; A perovskite photoactive layer is prepared by a solution method on a side of the interface modification layer away from the hole transport layer; Wherein, the hole transport layer comprises a self-assembled monolayer; The interface modification layer includes an organic additive, and the organic additive has R1 and R2; R1 is a carboxylic acid group, and R2 is an amino group.

[0010] In the second aspect of the embodiment of the present application, a solution method is used to prepare a perovskite photoactive layer on the interface modification layer, which improves the wettability of the perovskite precursor solution on the interface modification layer, and the prepared perovskite photoactive layer is more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0012] Figure 1 This is a SEM image provided in Example 1 of the present application; Figure 2 This is the SEM image provided in Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0013] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0014] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. When the second element, component, region, layer or part is discussed, it does not indicate that the present application necessarily has the first element, component, region, layer or part.

[0015] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0016] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0017] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0018] When single-layer sub-self-assembled materials are used as hole transport layers in inverse perovskite cells, there is a problem of poor wettability with the perovskite precursor solution.

[0019] Based on this, the present application introduces a layer of iminodiacetic acid interface modification layer at the interface between the monomolecular self-assembled layer and the perovskite photoactive layer to improve the performance of the device. The embodiment of the present application provides a perovskite solar cell and a method for preparing the same. Based on this, the problem of poor wettability of the monomolecular self-assembled layer to the perovskite precursor solution is solved. See below for details.

[0020] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0021] A first aspect of an embodiment of the present application provides a perovskite solar cell.

[0022] In some embodiments, the perovskite solar cell comprises: a hole transport layer, an interface modification layer and a perovskite photoactive layer are stacked; Wherein, the hole transport layer comprises a self-assembled monolayer; The interface modification layer includes an organic additive, and the organic additive has an R1 group and an R2 group; R1 is a carboxylic acid group, and R2 is an amino group.

[0023] In the embodiments of the present application, by introducing an interface modification layer including an organic additive, the problem of poor wettability of the self-assembled monolayer to the perovskite precursor solution can be improved when the perovskite photoactive layer is prepared by a solution method. Specifically, the carboxyl group in the organic additive can improve the uneven coverage of the perovskite photoactive layer due to the hydrophobicity of the SAMs material, and the amino group in the organic additive can also improve the wettability. When the carboxyl group and the amino group are in contact with a polar solvent, hydrogen bonds can be formed, thereby enhancing the interaction between the perovskite precursor solution and the interface modification layer. In addition, the polarity of the carboxyl group enables it to form strong interaction forces with the materials in the perovskite precursor solution, including ionic bonds, hydrogen bonds, etc., which helps to improve wettability. In addition to improving wettability, the carboxyl group in the organic additive can also passivate defects at the interface between the perovskite and SAMs, and can interact with free Pb + The amino group in the organic additive also has the function of passivating defects. In cooperation with the carboxyl group, the photoelectric conversion efficiency of the perovskite solar cell can be significantly improved.

[0024] It can be understood that the perovskite solar cell described in the embodiments of the present application is a trans structure.

[0025] In some embodiments, in a perovskite solar cell, the organic additive includes at least one of iminodiacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, nitrilotriacetic acid, and iminodipropionic acid.

[0026] In some embodiments, in a perovskite solar cell, the self-assembled monolayer includes at least one of a monomolecular self-assembled material containing a phosphonic acid group and a monomolecular self-assembled material containing a carboxylic acid group. Exemplarily, the monomolecular self-assembled material of the phosphonic acid group includes at least one of (2-(9H-carbazole-9-yl)ethyl)phosphonic acid (2PACZ), (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid (MeO-2PACZ), and (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid (Me-4PACZ). The monomolecular self-assembled material of the carboxylic acid group may be 9H-carbazole-2-carboxylic acid.

[0027] In some embodiments, in a perovskite solar cell, the thickness of the interface modification layer is 4 nm to 8 nm, for example, 4 nm, 6 nm, 8 nm, etc. Thus, while improving the wettability of the perovskite precursor solution, it also has good carrier transport performance.

[0028] In some embodiments, the perovskite solar cell further comprises a transparent conductive substrate, an electron transport layer, a hole blocking layer and a counter electrode; the transparent conductive substrate, the hole transport layer, the interface modification layer, the perovskite photoactive layer, the electron transport layer, the hole blocking layer and the counter electrode are stacked in sequence. Thus, the presence of the interface modification layer reduces the interface defects of the interface modification layer / perovskite photoactive layer, and the wettability of the interface modification layer to the perovskite precursor solution is improved, so that the distribution of the perovskite photoactive layer thereon is more uniform, so that the conversion efficiency of the inverse perovskite solar cell is improved.

[0029] The present application embodiment does not limit the material and thickness of the transparent conductive substrate, the electron transport layer, the hole blocking layer and the counter electrode. Preferably, the perovskite solar cell satisfies at least one of the following characteristics: (A) The chemical formula of the perovskite photoactive material in the perovskite photoactive layer is: ABX3; wherein A is selected from FA + 、MA + , Cs + , Rb + At least one of; B is selected from Pb 2+ ; X is selected from Cl - Br ‐ ,I ‐ At least one of; Exemplarily, the perovskite photoactive material in the perovskite photoactive layer may be FAMAPbI3, FACsPbI3 or FAMACsPbI3, whereby the two carboxyl groups in the iminodiacetic acid can react with the uncoordinated Pb in the perovskite photoactive layer 2+ (B) The thickness of the perovskite photoactive layer is 400nm to 600nm, for example, 400nm, 450nm, 500nm, 600nm, etc.; (C) The electron transport layer includes C 60 、Fullerene derivatives (PCBM (C 70)) at least one of; (D) the thickness of the electron transport layer is 20nm to 40nm, for example, 20nm, 30nm, 40nm, etc.; (E) the material of the hole blocking layer includes at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and SnO2; (F) the thickness of the hole blocking layer is 5nm to 10nm, for example, 5nm, 6nm, 8nm, 10nm; (G) the material of the counter electrode includes at least one of Au, Ag, and Cu; (H) the thickness of the counter electrode is 60nm to 80nm, for example, 60nm, 70nm, 80nm, etc. (I) the transparent conductive substrate includes fluorine-doped SnO2 conductive glass (FTO glass), indium tin oxide conductive glass (ITO glass) or a flexible ITO conductive substrate. This is conducive to optimizing the comprehensive performance of the inverse perovskite solar cell.

[0030] A second aspect of an embodiment of the present application provides a method for preparing a perovskite solar cell.

[0031] In some embodiments, the method for preparing the perovskite solar cell comprises the following operations: S1. Provide a transparent conductive substrate, on which a hole transport layer and an interface modification layer are sequentially stacked; wherein the hole transport layer comprises a self-assembled monolayer; and the interface modification layer comprises iminodiacetic acid. Thus, the wettability to the perovskite precursor solution is improved by introducing the interface modification layer.

[0032] Optionally, the transparent conductive substrate may be FTO glass, ITO glass or a flexible ITO conductive substrate.

[0033] In some specific embodiments, the hole transport layer may be a nickel oxide layer and a self-assembled monolayer stacked in sequence on a transparent conductive substrate; the hole transport layer may also be a self-assembled monolayer, thereby extracting and transporting holes.

[0034] In some specific embodiments, the hole transport layer can be prepared by spin coating. Optionally, a SAMs solution can be spin coated on a transparent conductive substrate, and then the solvent can be removed. The solute of the SAMs solution can include at least one of MeO-2PACZ, 2PACZ, Me-4PACZ, etc.; the solvent of the SAMs solution can be at least one of ethanol and isopropanol; the concentration of the SAMs solution is 0.2mg / ml~1mg / ml. Furthermore, the spin coating speed can be 2000rpm~3000rpm, for example, it can be 2000rpm, 2500rpm, 2800rpm, 3000rpm, etc. Optionally, the solvent can be removed by keeping warm at 100℃~120℃ for 10min~15min to remove the solvent and obtain a self-assembled monolayer stacked on a transparent conductive substrate.

[0035] In some specific embodiments, the interface modification layer can be prepared by spin coating.

[0036] Optionally, an iminodiacetic acid solution is spin-coated on the hole transport layer, and then the solvent is removed to obtain an interface modification layer.

[0037] Preferably, the thickness of the interface modification layer is 4 nm to 8 nm.

[0038] Furthermore, the concentration of the iminodiacetic acid solution may be 0.4 mg / ml to 1.2 mg / ml, for example, 0.4 mg / ml, 0.6 mg / ml, 0.8 mg / ml, 1 mg / ml, 1.2 mg / ml, etc.; the solvent may be at least one of ethanol and isopropanol.

[0039] Furthermore, the spin coating speed may be 2000 rpm to 3000 rpm. For example, the spin coating speed may be 2000 rpm, 2500 rpm, 2800 rpm, 3000 rpm, etc.

[0040] Furthermore, the temperature may be kept at 100° C. to 120° C. for 10 to 15 minutes to remove the solvent. For example, the temperature may be kept at 100° C., 110° C., 120° C., etc., and the time may be 10 minutes, 12 minutes, 14 minutes, 15 minutes, etc.

[0041] S2, preparing a perovskite photoactive layer by a solution method on the side of the interface modification layer away from the hole transport layer, thereby obtaining a uniformly distributed perovskite photoactive layer.

[0042] Furthermore, the solution method includes at least one of a spin coating method, a dip coating method, and a slit coating method.

[0043] In some embodiments, in the preparation method of perovskite solar cells, the preparation of the perovskite photoactive layer by solution method includes: spin coating the perovskite precursor solution on the interface modification layer by spin coating, and then annealing to form the perovskite photoactive layer; wherein the perovskite precursor solution includes at least one of FAMAPbI3, FACsPbI3, and FAMACsPbI3. Thus, the two carboxyl groups in the iminodiacetic acid can react with the uncoordinated Pb in the perovskite photoactive layer. 2+ Coordinate and passivate interface defects.

[0044] Furthermore, the solvent of the perovskite precursor solution may include at least one of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), γ-butyrolactone (GBL), and N-methylpyrrolidone (NMP). For example, a mixed solvent of DMF and DMSO in a volume ratio of (3-5):1, a mixed solvent of GBL and NMP in a volume ratio of (3-5):1, and a mixed solvent of DMF and NMP in a volume ratio of (3-5):1 may be used.

[0045] Furthermore, the rotation speed of spin coating the perovskite precursor solution may be 4000 rpm to 6000 rpm, for example, 4000 rpm, 5000 rpm, 6000 rpm, etc.

[0046] Furthermore, the annealing temperature is 100° C. to 150° C., and the annealing time is 15 min to 35 min. Thus, a well-crystallized perovskite photoactive layer can be obtained.

[0047] The following will conduct performance tests on the structure or preparation method of the perovskite solar cell provided in the embodiments of the present application and related comparative examples.

[0048] [Example 1] Step 100: Surface cleaning of FTO glass: Step 101: placing the FTO glass in an ultrasonic cleaning device, and cleaning the FTO glass with detergent-free water, deionized water, and ethanol in steps, each cleaning step lasting 20 minutes, and then drying with nitrogen for use; Step 102: treating the ultrasonically cleaned FTO glass with ultraviolet ozone for 20 min; Step 200: Preparation of hole transport layer: Step 201: preparing an ethanol solution of Me-4PACZ with a concentration of 0.6 mg / ml; Step 202: spin-coating the ethanol solution of Me-4PACZ on the FTO glass at a rotation speed of 3000 rpm, and then keeping it at 100° C. for 10 min to obtain a hole transport layer with a thickness of 1 nm; Step 300: Preparation of interface modification layer: Step 301: preparing a 0.8 mg / ml ethanol solution of iminodiacetic acid; Step 302: spin-coating an ethanol solution of iminodiacetic acid on the hole transport layer at a rotation speed of 3000 rpm and keeping the temperature at 100° C. for 10 minutes to obtain an interface modification layer with a thickness of 6 nm; Step 400: Preparation of perovskite photoactive layer: Step 401: preparing a FAMAPbI3 solution with a concentration of 1.2 mol / L as a perovskite precursor solution; The solvent of the FAMAPbI3 solution was a mixed solvent of DMF and NMP with a volume ratio of 4:1; Step 402: Spin-coat the perovskite precursor solution onto the hole transport layer in step 202, and deposit the thin film using a one-step spin coating method, with a spin coating speed of 5000 rpm and a time of 30 seconds; Step 403: 5 seconds before the end of the spin coating deposition, 300 μL of anisole is added dropwise to obtain a perovskite wet film; Step 404: annealing at 150° C. for 10 min to obtain a 400 nm thick perovskite photoactive layer; Step 500: Preparation of electron transport layer: Step 501: Evaporate 30nm C on the perovskite photoactive layer at 0.5Å / s 60 , as an electron transport layer; Step 600: Preparation of hole blocking layer: Step 601: evaporating 6 nm BCP at 0.5 Å / s on the electron transport layer as a hole blocking layer; Step 700: Prepare metal electrodes: Step 701: thermally evaporate a gold film on the hole blocking layer and evaporate a 70nm silver electrode.

[0049] [Example 2] The other steps are the same as those in Example 1, except that: Step 302: spin-coat the iminodiacetic acid ethanol solution on the hole transport layer, and obtain an interface modification layer with a thickness of 4 nm by changing the number of spin-coating.

[0050] [Example 3] The other steps are the same as those in Example 1, except that: Step 302: spin-coat the iminodiacetic acid ethanol solution on the hole transport layer, and obtain an interface modification layer with a thickness of 8 nm by changing the number of spin-coating.

[0051] [Example 4] The other steps are the same as those in Example 1, except that: Step 302: Spin-coat the iminodiacetic acid ethanol solution on the hole transport layer, and obtain an interface modification layer with a thickness of 2 nm by changing the number of spin-coating.

[0052] [Example 5] The other steps are the same as those in Example 1, except that: Step 302: spin-coat the iminodiacetic acid ethanol solution on the hole transport layer, and obtain an interface modification layer with a thickness of 10 nm by changing the number of spin-coating.

[0053] [Example 6] The other steps are the same as those in Example 1, except that: The iminodiacetic acid in step 300 is replaced by diethylenetriaminepentaacetic acid.

[0054] [Example 7] The other steps are the same as those in Example 1, except that: The iminodiacetic acid in step 300 is replaced by ethylenediaminetetraacetic acid.

[0055] [Comparative Example 1] The other steps are the same as those in Example 1, except that: There is no preparation of the interface modification layer in step 300 .

[0056] [Comparative Example 2] The other steps are the same as those in Example 1, except that step 200 and step 300 are combined into: A solution was prepared, wherein the solvent was ethanol, and the solution contained 0.6 mg / ml Me-4PACZ and 0.8 mg / ml iminodiacetic acid; The solution was spin-coated on FTO glass at a rotation speed of 3000 rpm, and then kept at 100° C. for 10 min to obtain a 7 nm thick hole transport layer containing iminodiacetic acid.

[0057]

Test example

[0058] 2. The variables of Examples 1 to 7 and Comparative Examples 1 to 2 are shown in Table 1. When the light intensity is 1000 W / m 2 (AM 1.5G spectrum), IV tests were performed on the perovskite cells of Examples 1 to 7 and Comparative Examples 1 to 2 at a temperature of 25°C. The results are also shown in Table 1.

[0059] Table 1

[0060] Note: Jsc is short-circuit current; Voc is open-circuit voltage; FF is fill factor; PCE is conversion efficiency.

[0061] As can be seen from Table 1 above, the conversion efficiency of Examples 1 to 5 is improved to varying degrees compared to Comparative Examples 1 to 2. This is because the introduction of the interface modification layer optimizes the wettability of the perovskite precursor solution, allowing the perovskite precursor solution to spread on the interface modification layer, which is conducive to forming a uniformly distributed and high-coverage perovskite photoactive layer. In Comparative Example 2, the interface modification material and the self-assembly material are mixed to prepare the hole transport layer, and the improved performance is not as good as that of Examples 1 to 7. This is because the organic additives are mixed with the single-molecule self-assembly material for spin coating, and the amino groups thereof will affect the anchoring of the single-molecule self-assembly material and the uniformity of the SAMs, so that the hole transport layer mixed with the organic additives is not as good as the interface modification layer composed of the organic additives to improve the wettability of the perovskite precursor solution.

[0062] It should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0063] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0064] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0065] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A perovskite solar cell, characterized in that: include: A hole transport layer, an interface modification layer and a perovskite photoactive layer are stacked; Wherein, the hole transport layer comprises a self-assembled monolayer; The interface modification layer includes an organic additive, and the organic additive has R1 and R2; R1 is a carboxylic acid group, and R2 is an amino group.

2. The perovskite solar cell according to claim 1, characterized in that The organic additive includes at least one of iminodiacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, nitrilotriacetic acid, and iminodipropionic acid.

3. The perovskite solar cell according to claim 1, characterized in that The self-assembled monolayer includes at least one of a monomolecular self-assembled material containing a phosphonic acid group and a monomolecular self-assembled material containing a carboxylic acid group.

4. The perovskite solar cell according to claim 1, characterized in that The thickness of the interface modification layer is 4 nm to 8 nm.

5. The perovskite solar cell according to any one of claims 1 to 4, characterized in that: The perovskite solar cell also includes a transparent conductive substrate, an electron transport layer, a hole blocking layer and a counter electrode; The transparent conductive substrate, the hole transport layer, the interface modification layer, the perovskite photoactive layer, the electron transport layer, the hole blocking layer and the counter electrode are stacked in sequence.

6. A method for preparing a perovskite solar cell, characterized in that: The following operations are included: Providing a transparent conductive substrate, on which a hole transport layer and an interface modification layer are sequentially stacked; A perovskite photoactive layer is prepared by a solution method on a side of the interface modification layer away from the hole transport layer; Wherein, the hole transport layer comprises a self-assembled monolayer; The interface modification layer includes an organic additive, and the organic additive has R1 and R2; R1 is a carboxylic acid group, and R2 is an amino group.

7. The method for preparing a perovskite solar cell according to claim 6, characterized in that: The solution method includes at least one of a spin coating method, a dip coating method, and a slit coating method.

8. The method for preparing a perovskite solar cell according to claim 6, characterized in that: The method of preparing the perovskite photoactive layer by a solution method comprises: Spin coating a perovskite precursor solution on the interface modification layer by a spin coating method, and then annealing to form a perovskite photoactive layer; Wherein, the perovskite precursor solution includes at least one of FAMAPbI3, FACsPbI3, and FAMACsPbI3.

9. The method for preparing a perovskite solar cell according to claim 8, characterized in that: The rotation speed of the spin coating is 4000 rpm to 6000 rpm; and / or The annealing temperature is 100°C to 150°C; and / or The solvent of the perovskite precursor solution includes at least one of N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, and N-methylpyrrolidone.

10. The method for preparing a perovskite solar cell according to any one of claims 6 to 9, characterized in that: The thickness of the interface modification layer is 4nm-8nm.

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