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 first electrode, a second electrode and a perovskite layer located between the first electrode and the second electrode, an electron transport layer is arranged between the perovskite layer and the first electrode, the material of the electron transport layer comprises a metal oxide, and organic molecules shown in the formula I are arranged between the perovskite layer and the electron transport layer. X in the organic molecules is adjacently combined with the electron transport layer, and-NH < 3 + > in the organic molecules is adjacently combined with the perovskite layer. On the basis of the organic molecule effect, the pore between the electron transmission layer and the perovskite layer can be improved, so that the interlayer combination is tighter, the electron transmission performance can be improved, and the energy conversion efficiency of the perovskite solar cell can be improved.

Description

Technical Field

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

[0002] Perovskite materials are a type of semiconductor materials with uniform size and high color purity. Their elemental composition has a crystal structure similar to that of the mineral CaTiO3. Perovskite materials have strong light absorption capacity and a wide absorption range, and have great advantages in the field of optoelectronics. For example, perovskite solar cells (PSCs) with perovskite materials as light-absorbing layers have developed rapidly. They have excellent carrier mobility, high absorption coefficient and low-cost solution processing, and have attracted widespread attention from the business community.

[0003] Metal oxides are generally used as electron transport layer materials in perovskite solar cells. The surface of such electron transport layers generally produces a porous structure, and the crystal structure of the perovskite film still has crystal defects. There are many pores between the perovskite layer and the electron transport layer of the metal oxide, which leads to a decrease in the performance of the perovskite solar cell. Summary of the invention

[0004] The purpose of the present application is to provide a perovskite solar cell and a method for preparing the same, aiming to solve the technical problem of how to improve the interlayer gap between the electron transport layer and the perovskite layer in the perovskite solar cell to improve its performance.

[0005] In order to achieve the above application purpose, the technical solution adopted in this application is as follows:

[0006] In a first aspect, the present application provides a perovskite solar cell, comprising a first electrode, a second electrode, and a perovskite layer located between the first electrode and the second electrode, an electron transport layer is provided between the perovskite layer and the first electrode, the material of the electron transport layer comprises a metal oxide, and an organic molecule as shown in formula I is provided between the perovskite layer and the electron transport layer;

[0007]

[0008] Wherein, X includes at least one of carbonyl, carboxyl, hydroxyl, thiol, imine, cyano and nitro, and R is -(CH2) n - or hydroxy-substituted -(CH2) n -, n is an integer greater than or equal to 1; X in the organic molecule is adjacent to the electron transport layer, -NH3 in the organic molecule + Adjacent to the perovskite layer.

[0009] In some embodiments, X is carboxyl; and / or n=2-5.

[0010] In some embodiments, the molar ratio of the organic molecule to the perovskite material in the perovskite layer is (0.01-0.04):1.

[0011] In some embodiments, the metal oxide includes at least one of TiO2, NiOx, SnO2, ZrO2, and ZnO;

[0012] And / or, a hole transport layer is provided between the perovskite layer and the second electrode.

[0013] In a second aspect, the present application provides a method for preparing a perovskite solar cell, comprising:

[0014] preparing an electron transport layer containing a metal oxide on the first electrode;

[0015] Depositing a perovskite precursor solution containing an organic molecule represented by Formula I on the surface of the electron transport layer, and then performing a heat treatment to obtain a perovskite layer;

[0016] preparing a second electrode on the perovskite layer;

[0017]

[0018] Wherein, X includes at least one of carbonyl, carboxyl, hydroxyl, thiol, imine, cyano and nitro, and R is -(CH2) n - or hydroxy-substituted -(CH2) n -, n is an integer greater than or equal to 1.

[0019] In some embodiments, the steps of preparing the perovskite precursor solution include:

[0020] Dissolving the halide salt corresponding to the organic molecule shown in Formula I and a perovskite precursor in a solvent to obtain the perovskite precursor solution;

[0021] Alternatively, the organic molecule represented by Formula II and the perovskite precursor are dissolved in a solvent, and then the pH value of the solution is adjusted to protonate the amino end of the organic molecule represented by Formula II to obtain the perovskite precursor solution;

[0022]

[0023] In some embodiments, the molar ratio of the halide salt corresponding to the organic molecule represented by Formula I to the perovskite precursor is (0.01-0.04):1; or, the molar ratio of the organic molecule represented by Formula II to the perovskite precursor is (0.01-0.04):1.

[0024] In some embodiments, the solvent includes at least one of dimethyl sulfoxide and N,N-dimethylformamide.

[0025] In some embodiments, the heat treatment temperature is 100-150°C.

[0026] In some embodiments, the step of preparing the second electrode on the perovskite layer includes: first preparing a hole transport layer on the surface of the perovskite layer, and then preparing the second electrode on the hole transport layer.

[0027] The perovskite solar cell provided in the first aspect of the present application has a unique organic molecule disposed between the perovskite layer and the electron transport layer containing the metal oxide, wherein the X group of the organic molecule can be combined with the metal oxide on the surface of the electron transport layer, and the protonated amino group (-NH3 + ) can be combined with the perovskite material of the perovskite layer. Based on the action of the organic molecules, the pores between the electron transport layer and the perovskite layer can be improved, making the interlayer bonding tighter, which is beneficial to improving the electron transport performance and thus improving the energy conversion efficiency of the perovskite solar cell.

[0028] The second aspect of the present application provides a method for preparing a perovskite solar cell, wherein a perovskite precursor solution containing an organic molecule represented by formula I is deposited on the surface of an electron transport layer containing a metal oxide, and then heat-treated to form a perovskite film layer. In this process, the organic molecule represented by formula I acts as a molecular template, and its X group can be combined with the metal oxide, while the protonated amino group (-NH3 + ) can be combined with perovskite materials, which is conducive to the nucleation of perovskite crystallization, allowing the perovskite to crystallize and grow along the porous surface of the electron transport layer and fill its porous structure. The generated perovskite layer can be more closely combined with the electron transport layer, which is beneficial to improve the electron transport performance. The final perovskite solar cell has a good energy conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 It is a schematic diagram of the process of depositing a perovskite precursor solution containing organic molecules into a film in the method for preparing a perovskite solar cell provided in an embodiment of the present application;

[0031] Figure 2: is a layout electron microscope image of a perovskite solar cell provided in an embodiment of the present application; wherein (a) is the interface between the perovskite layer and the electron transport layer formed without adding organic molecules, and (b) is the interface between the perovskite layer and the electron transport layer formed by adding organic molecules;

[0032] Figure 3 It is an XRD comparison diagram of the perovskite layer of the perovskite solar cell provided in the embodiment of the present application and the perovskite layer of the comparative example. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0035] In the present application, "at least one" means one or more, "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items.

[0036] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0037] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0038] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0039] The terms "first" and "second" are used only for descriptive purposes to distinguish objects such as substances from each other, and should not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0040] In perovskite solar cells, the surface of the electron transport layer formed by metal oxides generally has a porous structure, while the perovskite thin film layer has certain crystal defects, which easily lead to electron-hole recombination. In addition, the interlayer materials of the perovskite thin film layer and the electron transport layer are difficult to mix effectively, resulting in more pores between the layers. As a result, the free electrons generated by the perovskite are difficult to be effectively transferred to the external circuit by the electron transport layer, which in turn leads to a decrease in PSC performance.

[0041] Based on this, the present application fills a unique organic molecule between the electron transport layer and the perovskite layer of the perovskite solar cell, and based on the action of the organic molecule, the perovskite crystal growth has directionality, which can make the interface between the perovskite layer and the electron transport layer more tightly bonded. The specific technical solution is as follows.

[0042] In a first aspect, an embodiment of the present application provides a perovskite solar cell. The solar cell of the embodiment of the present application includes a first electrode, a second electrode, and a perovskite layer between the first electrode and the second electrode, an electron transport layer is provided between the perovskite layer and the first electrode, the material of the electron transport layer includes a metal oxide, and an organic molecule as shown in Formula I is provided between the perovskite layer and the electron transport layer.

[0043]

[0044] In the organic molecule represented by the above formula I, X includes at least one of a carbonyl group (Carbonyl Group, -CO-), a carboxyl group (Carboxyl Group, -COOH), a hydroxyl group (Hydroxyl Group, -OH), a thiol group (Thiols, -SH), an imine group (Imine Group, -C=N-), a cyano group (Cyano Group, -CN), and a nitro group (Nitro Group, -NO2), and R is -(CH2) n - or hydroxy-substituted -(CH2) n -, n is an integer greater than or equal to 1. Among them, X in the organic molecule can be combined with the metal oxide on the surface of the electron transport layer, and -NH3 + Combined with the perovskite material of the perovskite layer.

[0045] In the perovskite solar cell of the present application embodiment, the organic molecule represented by formula I is a protonated amino group (-NH3 + ) organic molecules, that is, the electrically neutral amino group (-NH2) becomes a positively charged group after protonation, and there are many types of X groups, and the above-mentioned types of X groups can be combined with metal oxides. Based on the binding effect of the organic molecule between the electron transport layer and the perovskite layer, the pores between the electron transport layer and the perovskite layer can be improved, making the interlayer bonding closer, which is conducive to improving the electron transport performance, thereby improving the energy conversion efficiency of perovskite solar cells.

[0046] In some embodiments, X in the organic molecule represented by the above formula I is a carboxyl group, which contains two oxygen atoms. The dioxygen chelation coordination of the carboxyl group can bind more tightly to the metal oxide, thereby further improving the binding stability between the electron transport layer and the perovskite layer.

[0047] In some embodiments, in the organic molecule represented by the above formula I, R is -(CH2) n - or hydroxy-substituted -(CH2) n -, n = 2 to 5, for example, n can be 2, 3, 4, 5, etc., specifically a straight chain type. Organic molecules with short carbon chains can better improve the electron transport capacity between the electron transport layer and the perovskite.

[0048] In some embodiments, the molar ratio of the organic molecule shown in the above formula I to the perovskite material in the perovskite layer is (0.01-0.04): 1. For example, the molar ratio of the organic molecule to the perovskite material can be 0.01: 1, 0.02: 1, 0.04: 1, etc. The organic molecules used in this ratio can well allow the perovskite to fill the porous gaps on the surface of the electron transport layer.

[0049] In some embodiments, the metal oxide of the electron transport layer includes at least one of titanium oxide (TiO2), nickel oxide (NiOx), tin oxide (SnO2), zirconium oxide (ZrO2), and zinc oxide (ZnO). The electron transport layer can be a layer of metal oxide or two layers of metal oxides stacked together, such as a dense metal oxide layer and a porous metal oxide layer stacked in sequence, and the surface of the electron transport layer bonded with organic molecules refers to the surface of the electron transport layer facing away from the first electrode, which generally has a porous structure.

[0050] In some embodiments, the chemical formula of the perovskite material of the perovskite layer may be ABM3; wherein A is a monovalent cation, which may be an organic cation and / or an inorganic cation, and a specific monovalent organic cation may include CH3NH3 + (MA + )、CH(NH2)2 + (FA +), the monovalent inorganic cation may include Rb + , Cs + At least one of; B is a divalent metal cation, which may specifically include Pb 2+ Sn 2+ At least one of; M is a monovalent anion, specifically a halogen ion, including Cl - Br - and I - At least one of .

[0051] In some embodiments, a hole transport layer may be provided between the perovskite layer and the second electrode to further improve the hole transport performance of the perovskite solar cell. Specifically, the material of the hole transport layer may include 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly-3-hexylthiophene (P3HT), triphenylamine (H101) with triptycene as the core, 3,4-ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA), N-(4-aniline)carbazole-spirobifluorene (CzPAF-SBF), poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), etc.

[0052] In some embodiments, the first electrode may be a transparent conductive substrate, including but not limited to the following materials: fluorine-doped tin oxide (FTO), indium-doped tin oxide (ITO), aluminum-doped zinc oxide (AZO), boron-doped zinc oxide (BZO), indium-doped zinc oxide (IZO), etc. The second electrode may be a metal electrode, such as gold, silver, copper, etc., or one or more of the conductive oxide electrodes.

[0053] In a second aspect, an embodiment of the present application provides a method for preparing a perovskite solar cell. The preparation method of the embodiment of the present application comprises:

[0054] S01: preparing an electron transport layer containing a metal oxide on the first electrode;

[0055] S02: depositing a perovskite precursor solution containing an organic molecule represented by formula I on the surface of the electron transport layer, and then performing a heat treatment to obtain a perovskite layer;

[0056] S03: preparing a second electrode on the perovskite layer.

[0057] When preparing a perovskite solar cell in the embodiment of the present application, a perovskite precursor solution containing an organic molecule shown in Formula I is deposited on the surface of an electron transport layer containing a metal oxide, and then heat treated to form a perovskite film layer. In this process, the organic molecule shown in Formula I acts as a molecular template, making the perovskite crystal growth directional, allowing the layer interface between the perovskite layer and the electron transport layer to be more tightly bonded, thereby facilitating the improvement of electron transport performance. The perovskite solar cell finally prepared has good energy conversion efficiency.

[0058] Specifically, the perovskite solar cell provided in the first aspect of the embodiment of the present application is prepared by the preparation method provided in the second aspect of the embodiment of the present application.

[0059] In step S01, the first electrode may be a transparent conductive substrate, including but not limited to the following materials: fluorine-doped tin oxide, indium-doped tin oxide, aluminum-doped zinc oxide, boron-doped zinc oxide, indium-doped zinc oxide, etc. The metal oxide of the electron transport layer prepared on the surface includes at least one of TiO2, NiOx, SnO2, ZrO2, and ZnO, and may be a single layer of metal oxide or two layers of metal oxide, for example, a dense metal oxide layer and a porous metal oxide layer prepared in sequence, which may be prepared by magnetron sputtering or solution spin coating.

[0060] In step S02, in the organic molecule represented by the above formula I in the perovskite precursor solution, X includes at least one of a carbonyl group, a carboxyl group, a hydroxyl group, a thiol group, an imine group, a cyano group, and a nitro group, and R is -(CH2) n - or hydroxy-substituted -(CH2) n -, n is an integer greater than or equal to 1, such as n = 3-5. The perovskite precursor in the perovskite precursor solution can be a monovalent halide AM and a divalent halide BM2 corresponding to the perovskite material chemical formula ABM3.

[0061] Taking the organic molecule where X is carboxyl and R is -(CH2)3- as an example, the chemical formula of the perovskite material is MAPbI3. Figure 1 As shown, when the perovskite precursor solution is deposited on the surface of the electron transport layer (ETL) and heat-treated to form a film, -NH3 + The functional group will form hydrogen bonds with the iodine ions in the perovskite, while the carboxyl group at the other end will produce coordination bonds with the porous electron transport layer material, thereby forming a monolayer between the electron transport layer and the perovskite layer. This allows the perovskite to be completely and tightly combined with the porous structure on the surface of the electron transport layer, so that the high electroactive area characteristics of the porous electron transport layer can be effectively utilized, and more electrons can be transferred per unit time more effectively, thereby reducing hysteresis or electron-hole recombination, thereby improving battery performance.

[0062] In some embodiments, the steps of preparing the perovskite precursor solution include:

[0063] Dissolving a halide salt corresponding to the organic molecule shown in Formula I and a perovskite precursor in a solvent to obtain a perovskite precursor solution;

[0064] Alternatively, the organic molecule represented by Formula II and the perovskite precursor are dissolved in a solvent, and then the pH value of the solution is adjusted to protonate the amino end of the organic molecule represented by Formula II to obtain a perovskite precursor solution;

[0065]

[0066] Wherein, the halogen salt corresponding to the organic molecule shown in Formula I, i.e. -NH3 in the molecular structure of Formula I + With F - , Cl - Br - ,I - The halogen salt formed by the plasma combination may be, for example, 3-propionic acid ammonium iodide, 3-propionic acid ammonium bromide, 4-butyric acid ammonium iodide, 4-butyric acid ammonium bromide, 5-aminopentanoic acid iodide, 5-aminopentanoic acid bromide, 6-aminopentanoic acid iodide, 6-aminopentanoic acid bromide, etc. In the organic molecule shown in formula II, X and R are the same as those in formula I, except that the amino group is not protonated, for example, it may be 3-aminopropionic acid, 4-aminobutyric acid, 4-amino-2-hydroxybutyric acid, 6-aminocaproic acid, and the amino group may be protonated by adjusting the pH value of the solution.

[0067] In some embodiments, the molar ratio of the halide salt corresponding to the organic molecule represented by Formula I to the perovskite precursor is (0.01-0.04):1; or, the molar ratio of the organic molecule represented by Formula II to the perovskite precursor is (0.01-0.04):1.

[0068] In some embodiments, the solvent includes at least one of dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF). For example, it can be a mixed solvent of DMF and DMSO in a weight ratio of (3-5):1, so that the organic molecules and the perovskite precursor can be better dissolved.

[0069] In some embodiments, the temperature of the heat treatment is 100-150° C. Under this temperature condition, the perovskite precursor solution can be well annealed to form a film.

[0070] In step S03, the step of preparing the second electrode on the perovskite layer may specifically include: first preparing a hole transport layer on the surface of the perovskite layer, and then preparing the second electrode on the hole transport layer. Among them, the material of the hole transport layer may include 2,2',7,7'-tetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly-3-hexylthiophene, triphenylamine with triptycene as the core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-aniline)carbazole-spirobifluorene, poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate), etc. The second electrode may be a metal electrode or a conductive oxide electrode.

[0071] The following describes the invention in conjunction with specific embodiments.

[0072] Example 1

[0073] A perovskite solar cell and a preparation method thereof. The perovskite solar cell structure sequentially comprises: a first electrode (material: FTO substrate), an electron transport layer (material: stacked dense TiO2 layer and meso-TiO2 layer), a perovskite layer (material: MAPbI3), a hole transport layer (material: Spiro-OMeTAD), and a second electrode (material: gold). An organic molecule shown in formula I is bonded between the perovskite layer and the electron transport layer, and R is -(CH2)2-, and X is a carboxyl group;

[0074]

[0075] The method for preparing the above-mentioned perovskite solar cell comprises:

[0076] Step 1: Clean the conductive FTO substrate, then sputter TiO2 on the FTO substrate, then spin-coat the meso-TiO2 nanoparticle suspension at 4000 rpm, and then anneal at 450°C to obtain an electron transport layer of about 200 nm.

[0077] Step 2: Prepare the perovskite precursor solution, dissolve PbI2 and MAI in a mixed solvent (DMF and DMSO mixed at a weight ratio of 4:1), where the molar ratio of PbI2 to MAI is 3:1, and the concentration of MAI is 0.25M (mol / L); then add 3-propionic acid ammonium iodide, the molar ratio of 3-propionic acid ammonium iodide to PbI2 is 0.01:1, and the perovskite precursor solution is obtained after uniform dispersion. The perovskite precursor solution is spin-coated on the electron transport layer at a speed of 2000rpm and annealed at 130℃ to obtain a perovskite layer of about 500nm.

[0078] Step 3: Spin-coat the chlorobenzene solution of Spiro-OMeTAD on the perovskite layer at 4000 rpm and anneal at 100 °C to obtain a hole transport layer of about 200 nm.

[0079] Step 4: Sputter gold on the hole transport layer to a thickness of about 80 nm to obtain the second electrode.

[0080] Comparative Example 1

[0081] A method for preparing a perovskite solar cell, which differs from the preparation steps of Example 1 in that, when preparing the perovskite precursor solution, 3-propionic acid ammonium iodide is replaced with 3-aminopropionic acid, and the solution remains neutral, and the amino groups of the organic molecules are not protonated. The other steps are the same as those of Example 1.

[0082] Comparative Example 2

[0083] A method for preparing a perovskite solar cell, which differs from the preparation steps of Example 1 in that 3-ammonium iodide is not added when preparing the perovskite precursor solution. The other steps are the same as those of Example 1.

[0084] Performance Testing

[0085] (1) Electron microscope image

[0086] like Figure 2 As shown, (a) is the interface between the perovskite layer and the electron transport layer formed in Example 2 without adding organic molecules, and (b) is the interface between the perovskite layer and the electron transport layer formed in Example 1 by adding organic molecules.

[0087] It can be seen that after the organic molecular template containing protonated amino groups is added to the perovskite precursor solution of Example 1, it can be clearly observed that the perovskite layer is tightly combined with the porous electron transport layer, and basically no unfilled porous structure is seen.

[0088] (2) XRD pattern

[0089] like Figure 3 As shown, the molecular template containing protonated amino groups in Example 1 allows the crystal growth of perovskite to be directional, so the XRD spectrum has special crystal planes, and strong (001) and (111) crystal planes are generated at 2θ≈5.8° and 23.2°. However, Comparative Examples 1 and 2 do not have such an effect. Therefore, the molecular template containing protonated amino groups can allow the perovskite to crystallize and grow along the porous electron transport layer and fill its porous structure.

[0090] (3)Perovskite solar cell performance test

[0091] The perovskite solar cell prepared in the above embodiment is connected to the solar simulator and the detection fixture of the battery performance detector, and the IV curve is scanned, and then the energy conversion efficiency PCE is calculated. avg , short-circuit current (Jsc), open-circuit voltage (Voc) and fill factor (FF), and the results are shown in Table 1.

[0092] Table 1

[0093] Case <![CDATA[PCE avg / %]]> <![CDATA[Jsc / mAcm -2 ]]> Voc / V FF Comparative Example 2 16.48 21.06 0.76 0.67 Comparative Example 1 16.37 20.99 0.72 0.65 Example 1 18.98 24.33 1.01 0.78

[0094] As can be seen from the above, Example 1 reduces the defect density of the perovskite material due to the addition of a protonated molecular template, thereby improving various performances of the battery; Comparative Example 1 is compared with Comparative Example 2, adding a non-protonated molecular template, and from the experimental results, the battery efficiency performance is not improved, but it is expected that the stability can be improved to a certain extent. The perovskite solar cell prepared in Example 1 of the present application can more effectively transfer more electrons per unit time, thereby improving the battery conversion efficiency performance.

[0095] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A perovskite solar cell, comprising a first electrode, a second electrode and a perovskite layer located between the first electrode and the second electrode, characterized in that: An electron transport layer is disposed between the perovskite layer and the first electrode, the material of the electron transport layer comprises a metal oxide, and an organic molecule as shown in Formula I is disposed between the perovskite layer and the electron transport layer; Wherein, X includes at least one of carbonyl, carboxyl, hydroxyl, thiol, imine, cyano and nitro, and R is -(CH2) n - or hydroxy-substituted -(CH2) n -, n is an integer greater than or equal to 1; X in the organic molecule is adjacent to the electron transport layer, -NH3 in the organic molecule + Adjacent to the perovskite layer.

2. The perovskite solar cell according to claim 1, characterized in that X is a carboxyl group; and / or n=2-5.

3. The perovskite solar cell according to claim 2, characterized in that The molar ratio of the organic molecules to the perovskite material in the perovskite layer is (0.01-0.04):

1.

4. The perovskite solar cell according to any one of claims 1 to 3, characterized in that: The metal oxide includes at least one of TiO2, NiOx, SnO2, ZrO2, and ZnO; And / or, a hole transport layer is provided between the perovskite layer and the second electrode.

5. A method for preparing a perovskite solar cell, characterized in that: include: preparing an electron transport layer containing a metal oxide on the first electrode; Depositing a perovskite precursor solution containing an organic molecule represented by Formula I on the surface of the electron transport layer, and then performing a heat treatment to obtain a perovskite layer; preparing a second electrode on the perovskite layer; Wherein, X includes at least one of carbonyl, carboxyl, hydroxyl, thiol, imine, cyano and nitro, and R is -(CH2) n - or hydroxy-substituted -(CH2) n -, n is an integer greater than or equal to 1.

6. The preparation method according to claim 5, characterized in that: The steps of preparing the perovskite precursor solution include: Dissolving the halide salt corresponding to the organic molecule shown in Formula I and a perovskite precursor in a solvent to obtain the perovskite precursor solution; Alternatively, the organic molecule represented by Formula II and the perovskite precursor are dissolved in a solvent, and then the pH value of the solution is adjusted to protonate the amino end of the organic molecule represented by Formula II to obtain the perovskite precursor solution; 7. The preparation method according to claim 6, characterized in that, The molar ratio of the halide salt corresponding to the organic molecule represented by formula I to the perovskite precursor is (0.01-0.04):1; or, the molar ratio of the organic molecule represented by formula II to the perovskite precursor is (0.01-0.04):

1.

8. The preparation method according to claim 6, characterized in that: The solvent includes at least one of dimethyl sulfoxide and N,N-dimethylformamide.

9. The preparation method according to any one of claims 5 to 8, characterized in that: The temperature of the heat treatment is 100-150°C.

10. The preparation method according to any one of claims 5 to 8, characterized in that: The step of preparing the second electrode on the perovskite layer includes: first preparing a hole transport layer on the surface of the perovskite layer, and then preparing the second electrode on the hole transport layer.

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