Perovskite precursor solution, preparation method of perovskite precursor solution, perovskite solar cell and preparation method of perovskite solar cell

Abstract

The invention relates to a perovskite precursor solution and a preparation method thereof, and a perovskite solar cell and a preparation method thereof. The perovskite precursor solution comprises an organic solvent and a solute, the solute comprises a perovskite precursor and amino cellulose; the perovskite precursor comprises A, B and X, A comprises at least one of FA < + >, MA < + >, Cs < + > and Rb < + >, B comprises at least one of Pb < 2 + >, Sn < 2 + > and Sr < 2 + >, and X comprises at least one of Cl <->, Br <-> and I <->; the ratio of the molar weight of B in the perovskite precursor to the mass of amino cellulose is 1.6 mmol: (1mg-2mg). The perovskite precursor solution can be used for preparing a perovskite layer of a perovskite solar cell, the effect of passivating internal defects of the prepared perovskite layer can be achieved, and then the conversion efficiency of the perovskite solar cell is improved.

Description

Technical Field

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

[0002] Perovskite solar cells have become a research hotspot in the photovoltaic field due to their excellent photoelectric performance, low cost, and flexibility. Although perovskite solar cells have high theoretical efficiencies, they are limited by inherent material and device issues. During the crystallization process, perovskite materials inevitably form grain boundary defects, bulk defects, and interface defects. These defects act as non-radiative recombination centers, shortening carrier lifetimes, reducing open-circuit voltage, and lowering fill factors, making it difficult for the device's photoelectric conversion efficiency to reach its theoretical limit. Therefore, passivating defects in the perovskite layer is a viable approach to reducing non-radiative recombination losses and improving device conversion efficiency.

[0003] However, conventional passivation methods for perovskite layers typically involve passivating the interface to reduce surface defects. These passivation methods only passivate the surface of the perovskite layer, but struggle to passivate internal defects, resulting in limited improvements in the conversion efficiency of perovskite solar cells. Summary of the Invention

[0004] Based on this, it is necessary to provide a perovskite precursor solution and a preparation method thereof, a perovskite solar cell and a preparation method thereof. The perovskite precursor solution of the present application can be used to prepare a perovskite layer of a perovskite solar cell, and can achieve the effect of passivating the internal defects of the prepared perovskite layer, thereby improving the conversion efficiency of the perovskite solar cell.

[0005] In a first aspect, the present application provides a perovskite precursor solution, comprising an organic solvent and a solute; the solute comprises a perovskite precursor and aminocellulose; the perovskite precursor comprises A, B and X, wherein A comprises FA + 、MA + 、Cs + and Rb + At least one of, B includes Pb 2+ 、Sn 2+ and Sr 2+ At least one of, X includes Cl - Br - and I - At least one of the following: the molar amount of B in the perovskite precursor and the mass ratio of the aminocellulose is 1.6 mmol: (1 mg ~ 2 mg).

[0006] In some embodiments, the aminocellulose includes at least one of aminomethylcellulose, aminoethylcellulose, aminopropylcellulose and polyaminocellulose.

[0007] In some embodiments, the aminocellulose includes at least one of 6-deoxy-6-aminocellulose and 6-deoxy-6-(2-aminoethyl)cellulose.

[0008] In a second aspect, the present application provides a method for preparing a perovskite precursor solution, comprising the following steps:

[0009] Dissolve the perovskite precursor raw materials and aminocellulose in an organic solvent; wherein the perovskite precursor raw materials include source A, source B and source X, wherein source A includes FA + 、MA + 、Cs + and Rb + At least one of the B source includes Pb 2+ 、Sn 2+ and Sr 2+ At least one of the X source includes Cl - Br - and I - At least one of the following: the molar amount of the B source in the perovskite precursor raw material and the mass ratio of the amino cellulose is 1.6 mmol: (1 mg ~ 2 mg).

[0010] In a third aspect, the present application provides a method for preparing a perovskite solar cell, comprising the following steps:

[0011] The perovskite layer is prepared using any one of the above-described perovskite precursor solutions or the perovskite precursor solution prepared by the above-described method for preparing a perovskite precursor solution.

[0012] In some embodiments, the preparation of the perovskite layer comprises the following steps:

[0013] Spin-coating the perovskite precursor solution on a substrate;

[0014] During the spin coating process, an anti-solvent is added dropwise to the perovskite precursor solution;

[0015] The substrate is subjected to an annealing treatment.

[0016] In some embodiments, the annealing treatment is performed at a temperature of 80°C to 150°C.

[0017] In some embodiments, the annealing treatment time is 20 min to 60 min.

[0018] In some embodiments, the method for preparing a perovskite solar cell comprises the following steps:

[0019] Providing a transparent substrate, wherein the transparent substrate has a transparent conductive layer;

[0020] forming a first charge extraction layer on the transparent conductive layer;

[0021] forming a perovskite layer on the surface of the first charge extraction layer;

[0022] forming a second charge extraction layer on the surface of the perovskite layer;

[0023] A metal electrode is prepared on the surface of the second charge extraction layer.

[0024] In a fourth aspect, the present application provides a perovskite solar cell, comprising a perovskite layer, wherein the perovskite layer is prepared using any one of the above-described perovskite precursor solutions or the above-described method for preparing the perovskite precursor solution.

[0025] In some embodiments, a perovskite solar cell includes a transparent conductive layer, a first charge extraction layer, the perovskite layer, a second charge extraction layer, and a metal electrode stacked in sequence.

[0026] Aminocellulose is cellulose that has been chemically modified to introduce functional amino groups. Due to its unique chemical structure, aminocellulose has good film-forming properties and processability, and exhibits excellent solubility in organic solvents. Introducing aminocellulose into a perovskite precursor solution can provide an effective way to passivate the internal defects of the perovskite layer. The molecular structure of aminocellulose contains functional groups such as amino (-NH2) and hydroxyl (-OH). During the film formation process, aminocellulose can not only form coordination bonds with uncoordinated B ions in the perovskite material, but also form hydrogen bonds / electrostatic interactions with A ions or X ions in the perovskite crystal through hydroxyl groups. By reducing vacancy defects of cations and anions in the perovskite layer and reducing non-radiative recombination, the photoelectric conversion efficiency of perovskite solar cells can be improved.

[0027] At the same time, the polymer main chain of aminocellulose has a certain degree of rigidity and molecular sequence regularity, which can serve as a nucleus-inducing template to promote the orderly nucleation and growth of perovskite crystals, thereby improving the film quality of perovskite films, increasing grain size, and reducing grain boundary defect density.

[0028] Furthermore, the flexibility of the chain segment structure of aminocellulose can also enhance the mechanical stability and thermal stress resistance of the perovskite film. The perovskite precursor solution of the present application shows application potential in flexible or large-area perovskite solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic structural diagram of a perovskite solar cell provided in one embodiment of the present application;

[0030] Figure 2 3 is a comparison diagram of the JV curves of the perovskite solar cells in Example 3 and Comparative Example 1;

[0031] Figure 3 The SEM images of the perovskite layer in Example 3 and Comparative Example 1 are compared, wherein: Figure 3 Figure a is the SEM image of the perovskite layer in Example 3. Figure 3 b is the SEM image of the perovskite layer in Comparative Example 1;

[0032] Figure 4 The efficiency change curves of the packaged devices of the perovskite solar cells in Example 3 and Comparative Example 1 were measured in maximum power point tracking mode under irradiation of an equivalent white light LED for 1 second in ambient air (65°C).

[0033] Description of Reference Numerals

[0034] 10-transparent conductive layer; 20-hole transport layer; 30-perovskite layer; 40-interface passivation layer; 50-electron transport layer; 60-metal electrode. DETAILED DESCRIPTION

[0035] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0037] In the description of the present application, it should be understood 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" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and 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 should not be understood as a limitation on the present application.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0039] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0040] An embodiment of the present application provides a perovskite precursor solution, comprising an organic solvent and a solute; the solute comprises a perovskite precursor and aminocellulose; the perovskite precursor comprises A, B and X, wherein A comprises FA + 、MA + 、Cs + and Rb + At least one of, B includes Pb 2+ 、Sn 2+ and Sr 2+ At least one of, X includes Cl - Br - and I - At least one of the following: the molar ratio of B in the perovskite precursor to the mass of aminocellulose is 1.6 mmol: (1 mg ~ 2 mg).

[0041] Aminocellulose is cellulose chemically modified to introduce functional amino groups. Due to its unique chemical structure, aminocellulose exhibits excellent film-forming properties and processability, and exhibits excellent solubility in organic solvents. Therefore, introducing aminocellulose into the perovskite precursor solution can provide a limited approach to passivating the internal defects of the perovskite layer. The molecular structure of aminocellulose contains both amino (-NH2) and hydroxyl (-OH) functional groups. During film formation, aminocellulose not only forms coordination bonds with uncoordinated B ions in the perovskite material, but also forms hydrogen bonds / electrostatic interactions with A or X ions in the perovskite crystal through the hydroxyl groups. This reduces vacancy defects in cations and anions in the perovskite layer, thereby reducing non-radiative recombination and thus improving the photoelectric conversion efficiency of perovskite solar cells.

[0042] At the same time, the polymer main chain of aminocellulose has a certain degree of rigidity and molecular sequence regularity, which can serve as a nucleus-inducing template to promote the orderly nucleation and growth of perovskite crystals, thereby improving the film quality of perovskite films, increasing grain size, and reducing grain boundary defect density.

[0043] Furthermore, the flexibility of the chain segment structure of aminocellulose can also enhance the mechanical stability and thermal stress resistance of the perovskite film. The perovskite precursor solution of the present application shows application potential in flexible or large-area perovskite solar cells.

[0044] Within the above-mentioned range of the ratio of the molar amount of the perovskite precursor to the mass of aminocellulose, aminocellulose has a good passivation effect on vacancy defects in the perovskite layer, and can also effectively promote the nucleation and growth of perovskite crystals, improve the quality of perovskite thin film formation, and improve the conversion efficiency of perovskite solar cells. When the ratio of the molar amount of the perovskite precursor to the mass of aminocellulose is too large, that is, when the amount of aminocellulose is too small, the passivation effect is relatively limited. When the ratio of the molar amount of the perovskite precursor to the mass of aminocellulose is too small, that is, when the amount of aminocellulose is too large, it is easy to have an adverse effect on the film formation effect of the perovskite thin film, thereby affecting the conversion efficiency of the perovskite solar cell.

[0045] It should be noted that the performance of perovskite solar cells is significantly affected by the crystallization effect of the perovskite layer. Therefore, when preparing the perovskite precursor solution, the molar amount of the perovskite precursor and the mass ratio of aminocellulose are controlled within a narrow range of 1.6mmol: (1mg~2mg). This allows aminocellulose to achieve a good passivation effect on the defects in the perovskite layer. At the same time, it can also promote the orderly nucleation and growth of perovskite crystals through the rigidity of its main chain and the regularity of its molecular sequence, thereby improving the conversion efficiency of the perovskite solar cell. Optionally, the ratio of the molar amount of the perovskite precursor to the mass of the aminocellulose is 1.6mmol:1mg, 1.6mmol:1.1mg, 1.6mmol:1.2mg, 1.6mmol:1.3mg, 1.6mmol:1.4mg, 1.6mmol:1.5mg, 1.6mmol:1.6mg, 1.6mmol:1.7mg, 1.6mmol:1.8mg, 1.6mmol:1.9mg or 1.6mmol:2mg, or the ratio of the molar amount of the perovskite precursor to the mass of the aminocellulose can also be within the range between any two of the above ratios.

[0046] In some embodiments, the aminocellulose includes at least one of aminomethylcellulose, aminoethylcellulose, aminopropylcellulose, and polyaminocellulose.

[0047] In some embodiments, the aminocellulose includes at least one of 6-deoxy-6-aminocellulose and 6-deoxy-6-(2-aminoethyl)cellulose.

[0048] Another embodiment of the present application provides a method for preparing a perovskite precursor solution, comprising the following steps:

[0049] The perovskite precursor raw materials and amino cellulose are dissolved in an organic solvent; wherein the perovskite precursor raw materials include source A, source B and source X, wherein source A includes FA + 、MA + 、Cs + and Rb + At least one of the B source includes Pb 2+ 、Sn 2+ and Sr 2+ At least one of the X source includes Cl - Br - and I - At least one of the following: the molar amount of the B source in the perovskite precursor raw material and the mass ratio of the aminocellulose is 1.6 mmol: (1 mg ~ 2 mg).

[0050] In some embodiments, the perovskite precursor raw materials include CsI, MAI, FAI, MACl, and PbI2.

[0051] In some embodiments, the organic solvent includes at least one of DMF and DMSO.

[0052] The present application provides a method for preparing a perovskite solar cell, comprising the following steps:

[0053] The perovskite layer is prepared using any of the above perovskite precursor solutions or the perovskite precursor solution prepared by the above method for preparing a perovskite precursor solution.

[0054] In some embodiments, the preparation of the perovskite layer comprises the following steps:

[0055] Spin-coat the perovskite precursor solution on the substrate;

[0056] During the spin coating process, the antisolvent is added dropwise to the perovskite precursor solution;

[0057] The substrate is annealed.

[0058] It is understood that the perovskite precursor solution of the present application can be applied to prepare a perovskite layer by an antisolvent method, and the antisolvent used is any one of the antisolvents commonly used in the art. For example, the antisolvent can be chlorobenzene.

[0059] In some embodiments, the annealing temperature is 80°C to 150°C.

[0060] Optionally, the temperature of the annealing treatment is 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C, or the temperature of the annealing treatment may also be within a range between any two of the above temperatures.

[0061] In some embodiments, the annealing time is 20 min to 60 min.

[0062] Optionally, the annealing time is 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, or the annealing time may be within the range between any two of the above times.

[0063] In some embodiments, the method for preparing a perovskite solar cell comprises the following steps:

[0064] Providing a transparent substrate having a transparent conductive layer thereon;

[0065] forming a first charge extraction layer on the transparent conductive layer;

[0066] forming a perovskite layer on the surface of the first charge extraction layer;

[0067] forming a second charge extraction layer on the surface of the perovskite layer;

[0068] A metal electrode is prepared on the surface of the second charge extraction layer.

[0069] It is understood that the perovskite precursor solution of the present application can be used to prepare both formal perovskite solar cells and inverse perovskite solar cells. When the perovskite solar cell is a formal perovskite solar cell, the first charge extraction layer is an electron transport layer, and the second charge extraction layer is a hole transport layer. When the perovskite solar cell is an inverse perovskite solar cell, the first charge extraction layer is a hole transport layer, and the second charge extraction layer is an electron transport layer.

[0070] The present application provides a perovskite solar cell, comprising a perovskite layer, wherein the perovskite layer is prepared using any of the above-mentioned perovskite precursor solutions or the above-mentioned method for preparing the perovskite precursor solution.

[0071] In some embodiments, the perovskite solar cell includes a transparent conductive layer, a first charge extraction layer, a perovskite layer, a second charge extraction layer, and a metal electrode stacked in sequence.

[0072] Reference Figure 1 As shown, in some embodiments, the perovskite solar cell includes: a transparent conductive layer 10, a hole transport layer 20, a perovskite layer 30, an interface passivation layer 40, an electron transport layer 50 and a metal electrode 60 stacked in sequence.

[0073] In some embodiments, the perovskite solar cell includes: a transparent conductive layer, an electron transport layer, an interface passivation layer, a perovskite layer, a hole transport layer, and a metal electrode stacked in sequence.

[0074] In some embodiments, the material of the transparent conductive layer includes at least one of ITO, IZO, IWO, ICO, and AZO.

[0075] In some embodiments, the material of the hole transport layer includes at least one of 2PACz, MeO-2PACz, NiO, PTAA, and Spiro-OMeTAD.

[0076] In some embodiments, the material of the electron transport layer includes at least one of fullerene and its derivatives, SnO2, TiO2, ZnO and In2O3.

[0077] In some embodiments, the material of the metal electrode includes at least one of Al, Ag, Cu, and Au.

[0078] The following are specific embodiments

[0079] Example 1

[0080] Preparation of perovskite solar cells:

[0081] (1) Preparation of perovskite precursor solution

[0082] Prepare 1 mL of 1.6 M Cs 0.05 MA 0.1 FA 0.85 PbI3 perovskite precursor solution. Appropriate amounts of CsI, MAI, FAI, and PbI2 were dissolved in a stoichiometric ratio in a 4:1 DMF / DMSO mixture. 10 mol% of MACl was added to the mixture to optimize the crystalline quality and morphology of the perovskite film. 1.0 mg of 6-deoxy-6-aminocellulose was also added. The solution was magnetically stirred at room temperature for 4 hours to ensure complete dissolution. The solution was then filtered through a 0.22 μm polytetrafluoroethylene (PTFE) membrane to remove undissolved impurities, yielding the perovskite precursor solution.

[0083] (2) Substrate pretreatment

[0084] The ITO substrate was ultrasonically treated with detergent, deionized water, anhydrous ethanol, acetone and isopropanol for 10 minutes respectively, then blown dry, and treated with ultraviolet ozone for 15 minutes to remove organic pollutants and enhance the hydrophilicity of the substrate surface.

[0085] (3) Preparation of hole transport layer

[0086] A 0.4 mg / mL MeO-2PACz methanol solution was dropwise added to the pretreated ITO substrate. A self-assembled monolayer (SAM) was formed by spin coating (3000 rpm for 30 seconds). After spin coating, the sample was annealed on a hot plate at 100°C for 10 minutes.

[0087] (4) Preparation of perovskite layer

[0088] 60 μL of the perovskite precursor solution in step (1) was deposited on the hole transport layer, first spin-coated at 2000 rpm for 10 s, then spun at 5000 rpm for 40 s. During the last 15 s of the spin-coating, 160 μL of chlorobenzene was added dropwise as an antisolvent to the substrate, and then the substrate was quickly transferred to 100 °C for annealing for 30 min.

[0089] (5) Preparation of interface passivation layer

[0090] A piperazine hydroiodide (PI) isopropanol solution with a concentration of 0.4 mg / mL was added dropwise to the surface of the annealed perovskite layer and spin-coated at 5000 rpm for 30 seconds. The substrate was then quickly transferred to 80°C for annealing for 10 minutes.

[0091] (6) Preparation of electron transport layer

[0092] After the substrate was cooled to room temperature, it was first -4 Pa) was thermally evaporated at a deposition rate of 0.3 Å / s to deposit 25 nm of C 60 Then, a 20nm SnO2 thin film was deposited using atomic layer deposition (ALD) using TDMASn and deionized water as precursors.

[0093] (7) Preparation of metal electrodes

[0094] The perovskite solar cell with an electron transport layer was thermally evaporated with 100 nm of Ag at an evaporation rate of 1 Å / s.

[0095] Example 2

[0096] Preparation of perovskite solar cells:

[0097] The preparation method of the perovskite solar cell in Example 2 is basically the same as that in Example 1, with the only difference being that, in step (1), 1.0 mg of 6-deoxy-6-aminocellulose is replaced with 6-deoxy-6-(2-aminoethyl)cellulose.

[0098] Example 3

[0099] Preparation of perovskite solar cells:

[0100] The preparation method of the perovskite solar cell in Example 3 is basically the same as that in Example 2, with the only difference being that in step (1), the mass of 6-deoxy-6-(2-aminoethyl) cellulose is 1.5 mg.

[0101] Example 4

[0102] Preparation of perovskite solar cells:

[0103] The preparation method of the perovskite solar cell in Example 4 is basically the same as that in Example 2, with the only difference being that in step (1), the mass of 6-deoxy-6-(2-aminoethyl) cellulose is 2 mg.

[0104] Comparative Example 1

[0105] Preparation of perovskite solar cells:

[0106] The preparation method of the perovskite solar cell in Comparative Example 1 is basically the same as that in Example 1, with the only difference being that aminocellulose is not added in the preparation of the perovskite precursor solution in step (1).

[0107] Device performance test

[0108] The perovskite solar cell devices prepared in Examples 1-4 and Comparative Example 1 were subjected to JV testing under a calibrated AM1.5G standard solar simulator, with an onset voltage of 1.2V, a cutoff voltage of -0.1V, and a scan rate of 10mV / s. Test parameters included open-circuit voltage (Voc), short-circuit current (Jsc), fill factor (FF), and photoelectric conversion efficiency (PCE). The test results are shown in Table 1:

[0109] Table 1

[0110]

[0111] By comparing the test data of Example 1, Example 2 and Comparative Example 1, it can be seen that in Comparative Example 1, no aminocellulose was added and the conversion efficiency was only 23.06%. In Example 1, by adding 6-deoxy-6-aminocellulose to the perovskite precursor solution, the photoelectric conversion efficiency was increased to 23.50%. In Example 2, by adding 6-deoxy-6-(2-aminoethyl) cellulose, the efficiency was increased to 24.47%. This is attributed to the aminocellulose introduced in Examples 1 and 2, which reduced the vacancy defects of cations and anions in the perovskite layer and reduced non-radiative recombination, thereby improving the photoelectric conversion efficiency of the perovskite solar cell. Compared with the 6-deoxy-6-aminocellulose in Example 1, the 6-deoxy-6-(2-aminoethyl) cellulose in Example 2 introduced a flexible side chain (-CH2CH2-), which allowed the terminal primary amine (-NH2) to more freely approach the defect sites in the perovskite crystal, especially the uncoordinated Pb 2+ As well as Pb vacancies and I vacancies. In addition, the 6-deoxy-6-aminocellulose in Example 1 has only one amino group and can only coordinate at a single point, while the 6-deoxy-6-(2-aminoethyl) cellulose structure in Example 2 contains a secondary amine (-NH-) and a primary amine (-NH2), which can provide a stronger electron donor, improve the affinity with metal ions, and more easily form a stable Lewis acid-base coordination on the surface / bulk of the perovskite material, forming a double-point coordination structure or a bridging structure to stabilize the grain boundary. It can be seen from the test data of Examples 2, 3, and 4 that by increasing the addition amount of 6-deoxy-6-(2-aminoethyl) cellulose, when the addition amount is 1.5 mg, the efficiency reaches 25.01%. Further increasing the addition amount, the efficiency drops significantly (Example 4 drops to 23.89%). Figure 23 is a comparison diagram of the JV curves of the perovskite solar cells in Example 3 and Comparative Example 1.

[0112] The samples in Example 3 and Comparative Example 1 were tested by scanning electron microscope (SEM) respectively. The SEM results are shown in the following images: Figure 3 shown. Figure 3 Figure a is the SEM image of the perovskite layer in Example 3. Figure 3 Figure b is the SEM image of the perovskite layer in Comparative Example 1. Figure 3 There is less PbI2 in a, and the grains are relatively Figure 3 The obvious increase of b is mainly due to the fact that the polymer main chain of aminocellulose has a certain degree of rigidity and molecular sequence regularity, which can serve as a crystal nucleus induction template to promote the orderly nucleation and growth of perovskite crystals, thereby improving the film quality of perovskite films and increasing the grain size.

[0113] The devices obtained in Example 3 and Comparative Example 1 were encapsulated with UV glue and cover glass, and then the devices were placed in ambient air (65°C) under 1 second of continuous irradiation with an equivalent white light LED in the maximum power point tracking mode to measure the stability of the encapsulated devices (MPPT). The results are as follows: Figure 4 As shown in the figure, after 500 hours, the PCE of the device in Example 3 dropped to 86.7%, while the PCE of the device in Comparative Example 1 dropped to 69.2%. The stability of the perovskite solar cell in Example 3 is better. This is because the 6-deoxy-6-(2-aminoethyl) cellulose in the perovskite precursor solution in Example 3 effectively passivates crystal defects, reduces the defect states of the perovskite, and improves device stability. In addition, the flexibility of its segment structure also enhances the stability and thermal stress resistance of the perovskite film.

[0114] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0115] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art could make several modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the patent in this application shall be based on the appended claims, and the specification and drawings may be used to interpret the claims.

Claims

1. A perovskite precursor solution, characterized in that Comprising an organic solvent and a solute; the solute comprises a perovskite precursor and aminocellulose; the perovskite precursor comprises A, B and X, wherein A comprises FA + 、MA + 、Cs + and Rb + At least one of, B includes Pb 2+ 、Sn 2+ and Sr 2+ At least one of, X includes Cl - Br - and I - At least one of the following: the molar amount of B in the perovskite precursor and the mass ratio of the aminocellulose is 1.6 mmol: (1 mg ~ 2 mg).

2. The perovskite precursor solution according to claim 1, characterized in that The aminocellulose includes at least one of aminomethyl cellulose, aminoethyl cellulose, aminopropyl cellulose and polyamino cellulose.

3. The perovskite precursor solution according to claim 1, characterized in that The aminocellulose includes at least one of 6-deoxy-6-aminocellulose and 6-deoxy-6-(2-aminoethyl)cellulose.

4. A method for preparing a perovskite precursor solution, characterized in that: The steps include: Dissolve the perovskite precursor raw materials and aminocellulose in an organic solvent; wherein the perovskite precursor raw materials include source A, source B and source X, wherein source A includes FA + 、MA + 、Cs + and Rb + At least one of the B source includes Pb 2+ 、Sn 2+ and Sr 2+ At least one of the X source includes Cl - Br - and I - At least one of the following: the molar amount of the B source in the perovskite precursor raw material and the mass ratio of the amino cellulose is 1.6 mmol: (1 mg ~ 2 mg).

5. A method for preparing a perovskite solar cell, characterized in that: The steps include: The perovskite layer is prepared using the perovskite precursor solution according to any one of claims 1 to 3 or the perovskite precursor solution prepared by the preparation method of the perovskite precursor solution according to claim 4.

6. The method for preparing a perovskite solar cell according to claim 5, wherein: The preparation of the perovskite layer comprises the following steps: Spin-coating the perovskite precursor solution on a substrate; During the spin coating process, an anti-solvent is added dropwise to the perovskite precursor solution; The substrate is subjected to an annealing treatment.

7. The method for preparing a perovskite solar cell according to claim 6, wherein: The annealing temperature is 80°C to 150°C; and / or, The annealing treatment time is 20 min to 60 min.

8. The method for preparing a perovskite solar cell according to claim 6, wherein: The steps include: Providing a transparent substrate, wherein the transparent substrate has a transparent conductive layer; forming a first charge extraction layer on the transparent conductive layer; forming a perovskite layer on the surface of the first charge extraction layer; forming a second charge extraction layer on the surface of the perovskite layer; A metal electrode is prepared on the surface of the second charge extraction layer.

9. A perovskite solar cell, characterized in that: The perovskite layer comprises a perovskite layer, wherein the perovskite layer is prepared using the perovskite precursor solution according to any one of claims 1 to 3 or the preparation method of the perovskite precursor solution according to claim 4.

10. The perovskite solar cell according to claim 9, characterized in that: The invention comprises a transparent conductive layer, a first charge extraction layer, the perovskite layer, a second charge extraction layer and a metal electrode which are stacked in sequence.

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