Perovskite solar cell, preparation method thereof and laminated solar cell

Abstract

The invention relates to the field of photovoltaic technology, and discloses a perovskite solar cell, a preparation method thereof and a laminated solar cell. The perovskite solar cell comprises a substrate, a tin oxide electron transport layer, a perovskite light absorption layer, a hole transport layer and a metal electrode which are arranged in sequence, a nickel selenide doped conductive oxide film is arranged between the tin oxide electron transport layer and the perovskite light absorption layer, and the doping concentration of nickel selenide in the conductive oxide film is controlled to be 0.01-5 mmol / L. According to the invention, the conductive oxide film is added between the tin oxide electron transport layer and the perovskite light absorption layer, and the nickel selenide is doped in the film layer; therefore, the nickel selenide-doped conductive oxide film can regulate and control the energy level difference between the tin oxide electron transport layer and the perovskite light absorption layer, passivate perovskite interface defects, and fill and passivate oxygen vacancies and other defects of the tin oxide electron transport layer, so that recombination can be greatly reduced, the carrier collection efficiency can be improved, and the cell performance can be further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic technology, in particular to a perovskite solar cell, a preparation method thereof and a laminated solar cell. BACKGROUND

[0002] Perovskite solar cells (PSC) have become the third generation of solar cells with broad development prospects due to their excellent photoelectric performance, low material cost, abundant raw materials and diversified application scenarios.

[0003] As shown in the publication CN108389977A, a perovskite solar cell includes, from bottom to top, a conductive substrate, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer and an anode layer. Among them, titanium oxide (TiO2) has the advantages of ideal energy band position, high electron extraction rate and low recombination loss, and mature preparation process, and has become the most widely used electron transport layer (ETL) material. However, the electron mobility of titanium oxide is lower than that of tin oxide (SnO2). Therefore, selecting SnO2 as the electron transport layer can greatly improve the electron transport efficiency and further optimize the performance of the perovskite solar cell.

[0004] Although SnO2 has many advantages such as good chemical stability, low cost and light absorption, the energy level structure of SnO2 as the electron transport layer of PSC does not match the energy level of the perovskite light-absorbing layer, which is not conducive to the separation and extraction of electrons. Moreover, the SnO2 ETL has defect states such as oxygen vacancies, which will become charge recombination centers, increase recombination, and hinder the improvement of cell performance. In addition, the perovskite polycrystalline structure and its low-temperature solution preparation process result in the existence of B vacancy defects in the perovskite (ABX3) layer. These defects become non-radiative recombination centers, which significantly affect the performance and stability of PSC, hindering its commercialization. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art and provide a perovskite solar cell, a preparation method thereof and a laminated solar cell.

[0006] Based on this, the present application discloses a perovskite solar cell, which includes a substrate, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer and a metal electrode arranged in a laminated manner from bottom to top.

[0007] Among them, the electron transport layer is a tin oxide electron transport layer; a nickel selenide doped conductive oxide film is further arranged between the tin oxide electron transport layer and the perovskite light-absorbing layer, and the doping concentration of the nickel selenide in the conductive oxide film is controlled at 0.01-5 mmol / L.

[0008] Preferably, the doping concentration of the nickel selenide in the conductive oxide film is 0.5 mmol / L.

[0009] Preferably, the thickness of the nickel selenide doped conductive oxide film is 10-200 nm.

[0010] Further preferably, the thickness of the nickel selenide doped conductive oxide film is 20 nm.

[0011] Further preferably, the material of the conductive oxide film is at least one of tungsten oxide, zinc oxide, tin oxide, titanium oxide;

[0012] The A-site ions in the ABX3 material of the perovskite light-absorbing layer include but are not limited to one or more of cesium ions (Cs + ), methylammonium ions (CH3NH3, MA + ), potassium ions (K + ), rubidium ions (Rb + ), formamidinium ions (CH2(NH2) 2+ ); the B-site ions include but are not limited to one or more of lead ions (Pb 2+ ), tin ions (Sn 2+ ), calcium ions (Ca 2+ ), germanium ions (Ge 2+ ), copper ions (Cu 2+ ), zinc ions (Zn 2+ ), gallium ions (Ga 2+ ); and the X-site ions include but are not limited to one or more of iodine ions (I - ), bromine ions (Br - ), chlorine ions (Cl - ), fluorine ions (F - ), thiocyanate ions (SCN - ).

[0013] Further preferably, the substrate is an indium tin oxide conductive glass; the perovskite light-absorbing layer is Cs 0.05 (FA 0.9 MA 0.1 ) 0.95 Pb(I 0.9 Br 0.1 )3; the material of the hole transport layer is 4-(3,6-dimethyl-9H-carbazole-9-yl)butyl phosphonic acid; and the metal electrode is a silver electrode. Of course, the substrate, the perovskite light-absorbing layer, the hole transport layer and the metal electrode of the present application can also be made of other materials commonly used in the preparation of perovskite solar cells.

[0014] The present application also discloses a preparation method of a perovskite solar cell, which comprises the following preparation steps:

[0015] S1, pretreating the substrate;

[0016] S2, preparing a tin oxide electron transport layer on a surface of the pretreated substrate;

[0017] S3, preparing a nickel selenide doped conductive oxide film on a surface of the tin oxide electron transport layer away from the substrate;

[0018] S4, preparing a perovskite light absorbing layer on a surface of the nickel selenide doped conductive oxide film away from the tin oxide electron transport layer;

[0019] S5, preparing a hole transport layer on a surface of the perovskite light absorbing layer away from the nickel selenide doped conductive oxide film;

[0020] S6, preparing a metal electrode on a surface of the hole transport layer away from the perovskite light absorbing layer, thereby obtaining the perovskite solar cell.

[0021] Preferably, in step S3, the method for preparing the nickel selenide doped conductive oxide film is spin coating, blade coating, spray coating, chemical bath deposition, sputtering, atomic deposition or evaporation.

[0022] Preferably, in step S1, the pretreatment comprises: sequentially cleaning the substrate with acetone, anhydrous ethanol and deionized water, then blowing dry nitrogen, and then performing ultraviolet light and ozone treatment, thereby obtaining a clean substrate with surface hydrophilicity.

[0023] The application further discloses a laminated solar cell comprising the perovskite solar cell as described above.

[0024] Compared with the prior art, the application has at least the following beneficial effects:

[0025] Nickel selenide (NiSe) is a semiconductor material with high intrinsic electron mobility, and its conduction band minimum (CBM) is-3.8eV to-4.0eV, which is different due to the difference in crystal phase and crystal structure. The CBM of the common perovskite light absorbing layer is-3.8eV, and the CBM of the tin oxide as the electron transport layer is-4.3eV.

[0026] Based on this, the application introduces a nickel selenide doped conductive oxide film between the perovskite light absorbing layer and the tin oxide electron transport layer by taking nickel selenide as an additive, which can assist the film layer in regulating and optimizing the energy band structure, reducing the energy level offset, helping to form a smoother energy level gradient between the perovskite light absorbing layer and the tin oxide ETL, reducing the energy potential barrier of the electrons moving from the perovskite light absorbing layer to the tin oxide ETL, thereby significantly improving the charge extraction efficiency and rate, and promoting the efficient separation and extraction of electrons.

[0027] Moreover, the tin oxide ETL has defect states such as oxygen vacancies (these vacancies are the main non-radiative recombination centers), and these defects become charge recombination centers. The nickel selenide additive can interact with these defect sites, inhibit the ability of the oxygen vacancies and other defects to capture electrons, improve the electron mobility, and significantly reduce the loss of carrier recombination.

[0028] Furthermore, the interface between the perovskite light-absorbing layer and the tin oxide ETL is a key recombination region. The nickel atoms in the nickel selenide can also form coordination bonds with the uncoordinated B-site ions on the surface of the perovskite light-absorbing layer, effectively optimizing and passivating the defects such as dangling bonds and defect states at the interface between the tin oxide ETL and the perovskite light-absorbing layer, enhancing the chemical stability, reducing the non-radiative recombination at the interface, and thus greatly reducing the recombination.

[0029] Therefore, the perovskite solar cell of the present application can effectively solve the problems of surface recombination caused by the mismatch of energy levels between SnO2 as the electron transport layer and the perovskite light-absorbing layer, B-site vacancy defects in the perovskite light-absorbing layer, and oxygen vacancy defects in the SnO2 electron transport layer, and thus can effectively improve the short-circuit current density, open-circuit voltage, fill factor, and photoelectric conversion efficiency of the cell. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Figure 1 is a structural schematic diagram of a perovskite solar cell according to the present application.

[0031] Figure 1 is a structural schematic diagram of a perovskite solar cell according to the present application. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned objects, features and advantages of the present application more apparent and easy to understand, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] The preparation method of the perovskite solar cell according to the present application is described below with reference to Figure 1. Figure 1 which comprises the following preparation steps:

[0034] Step 1: Preparing a pretreated ITO (indium tin oxide) conductive glass as the substrate 1 (of course, the substrate 1 can also use other substrate materials commonly used in perovskite solar cells).

[0035] Step 2: Preparing a tin oxide electron transport layer 2 on the upper surface of the substrate 1.

[0036] Step 3: Preparing a nickel selenide-doped conductive oxide film 3 on the upper surface of the tin oxide electron transport layer 2.

[0037] In step 3, the conductive oxide film is at least one of tungsten oxide, zinc oxide, tin oxide, titanium oxide. The preparation method of the nickel selenide-doped conductive oxide film 3 includes but is not limited to spin coating, blade coating, spraying, chemical bath deposition, sputtering, atomic deposition or evaporation method; the thickness of the nickel selenide-doped conductive oxide film 3 is 10-200 nm.

[0038] In step 3, the doping concentration of nickel selenide in the conductive oxide film is controlled at 0.01-5 mmol / L.

[0039] In step 4, a perovskite light-absorbing layer 4 is prepared on the upper surface of the nickel selenide-doped conductive oxide film 3.

[0040] In step 4, the A-site ions in the ABX3 material of the perovskite light-absorbing layer include but are not limited to one or more of cesium ions (Cs + ), methylammonium ions (CH3NH3, MA + ), potassium ions (K + ), rubidium ions (Rb + ), formamidinium ions (CH2(NH2) 2+ ); the B-site ions include but are not limited to one or more of lead ions (Pb 2+ ), tin ions (Sn 2+ ), calcium ions (Ca 2+ ), germanium ions (Ge 2+ ), copper ions (Cu 2+ ), zinc ions (Zn 2+ ), gallium ions (Ga 2+ ); the X-site ions include but are not limited to one or more of iodine ions (I - ), bromine ions (Br - ), chlorine ions (Cl - ), fluorine ions (F - ), thiocyanate ions (SCN - ).

[0041] In step 5, a hole transport layer 5 is prepared on the upper surface of the perovskite light-absorbing layer 4.

[0042] In step 6, a metal electrode 6 is prepared on the upper surface of the hole transport layer 5.

[0043] The materials of the perovskite light-absorbing layer 4, the hole transport layer 5 and the metal electrode 6 refer to the materials commonly used in the preparation of the perovskite solar cell, and thus are not described in detail.

[0044] The perovskite solar cell of the present application is prepared by the preparation method of steps 1-6 of the above specific embodiments of the present application; for example, Figure 1As shown, the perovskite solar cell includes, from bottom to top, an ITO substrate 1, a tin oxide electron transport layer 2, a nickel selenide doped conductive oxide film 3, a perovskite light absorbing layer 4, a hole transport layer 5, and a metal electrode 6.

[0045] The perovskite solar cell of the present application adds a conductive oxide film (such as tungsten oxide, zinc oxide, tin oxide, or titanium oxide) between the tin oxide ETL and the perovskite light absorbing layer 4, and incorporates nickel selenide into the film layer. (1) The conduction band minimum of the nickel selenide is between the tin oxide and the perovskite material, which can make the energy level between the tin oxide ETL and the perovskite light absorbing layer 4 more matched, and is conducive to the separation and extraction of electrons. (2) The tin oxide ETL has defect states such as oxygen vacancies, and these defects can become charge recombination centers. The nickel selenide doped in the conductive oxide film can interact with these defect sites and inhibit their ability to capture electrons. At the same time, the Ni atoms in the nickel selenide can form coordination bonds with the uncoordinated B-site ions on the surface of the perovskite light absorbing layer 4, effectively passivating the dangling bonds and defect states at the interface, and reducing the non-radiative recombination at the interface. In this way, the perovskite solar cell of the present application can improve the energy level matching, optimize the contact interface, fill and passivate the defect states such as oxygen vacancies in the tin oxide electron transport layer 2, and passivate the interface defects such as B-site vacancies in the perovskite light absorbing layer 4, greatly reducing recombination and improving the collection efficiency of charge carriers. Therefore, it can effectively solve the problem of energy level mismatch between SnO2 as the electron transport layer and the perovskite light absorbing layer 4, the surface recombination problem caused by B-site vacancy defects in the perovskite layer, and the problem of oxygen vacancy defects in the SnO2 electron transport layer, thereby effectively improving the short-circuit current density, open-circuit voltage, fill factor, and photoelectric conversion efficiency of the cell.

[0046] The laminated solar cell of the present application includes the perovskite solar cell of the above specific embodiments of the present application.

[0047] The following gives a specific embodiment of a perovskite solar cell and a method for preparing the same.

[0048] Example 1

[0049] The method for preparing the perovskite solar cell of the present embodiment is described in detail with reference to Figure 1 , which includes the following preparation steps:

[0050] S1, select an indium tin oxide (ITO) conductive glass as a substrate 1, and sequentially clean the ITO substrate 1 with acetone, anhydrous ethanol, and deionized water. After cleaning, dry the substrate with dry nitrogen, and then perform ultraviolet light and ozone treatment to obtain a clean ITO substrate 1 with a hydrophilic surface. The thickness of the ITO substrate 1 is 120 nm.

[0051] S2, tin chloride (SnCl2·2H2O) is dissolved in N,N-dimethylformamide (DMF) solvent to prepare a precursor solution with a concentration of 0.15 mol / L, and stirred at room temperature on a magnetic stirrer for 10 min, and then transferred and left to stand to obtain a SnO2 precursor solution; 35 μL of the SnO2 precursor solution is spin-coated at a speed of 3000 rpm for 30 s, and annealed at 300°C for 60 min to form a 20 nm-thick SnO2 electron transport layer 2 on the upper surface of the ITO substrate 1.

[0052] S3, diisopropyl titanate (C 16 H 28 O6Ti) and n-butanol (C4H 10 O) are added in a volume ratio of 1:16 in a container to mix the DMF solution of nickel selenide, and stirred uniformly to obtain a nickel selenide-doped titanium oxide precursor solution (the concentration of nickel selenide is 0.5 mmol / L), and 30 μL of the nickel selenide-doped titanium oxide precursor solution is spin-coated dynamically at 2000 rpm for 3 times, each time for 48 s, and heated at 180°C for 10 min to form a 20 nm-thick nickel selenide-doped titanium oxide conductive film on the upper surface of the SnO2 electron transport layer.

[0053] S4, an appropriate amount of formamidinium iodide (FAI), cesium iodide (CsI), methylammonium bromide (MABr), lead bromide (PbBr2) and lead iodide (PbI2) are dissolved in a mixed solvent of DMF and DMSO (dimethyl sulfoxide) prepared in a volume ratio of 4:1, mixed uniformly to prepare a perovskite precursor solution, and the perovskite precursor solution is filtered for standby. A perovskite light-absorbing layer 4 (Cs 0.05 (FA 0.9 MA 0.1 ) 0.95 Pb(I 0.9 Br 0.1 )3) is deposited on the upper surface of the nickel selenide-doped titanium oxide conductive film by a two-step spin-coating method: the first step of spin-coating is at a speed of 1500 rpm for 15 s; the second step of spin-coating is at a speed of 4000 rpm for 20 s; and after the two steps of spin-coating, annealing is performed at 100°C for 30 min to obtain a 500 nm-thick perovskite light-absorbing layer 4.

[0054] S5, 0.5 mg of Me-4PACz (4-(3, 6-dimethyl-9H-carbazol-9-yl) butylphosphonic acid) was dissolved in 1 ml of ethanol, stirred uniformly at room temperature to obtain a mixed solution, which was used for the next step; the hole transport layer 5 was prepared by solution spin coating method, the spin coating speed of the mixed solution was 5000 rpm, the spin coating time was 20 s, and the ITO substrate after spin coating was annealed at 100°C for 15 min, so that the 5 nm thick hole transport layer 5 was prepared on the upper surface of the perovskite light-absorbing layer 4.

[0055] S6, a silver electrode was prepared on the upper surface of the hole transport layer 5 of step S5 by vacuum thermal evaporation method, and the thickness of the silver electrode was 200 nm. After step S6, a perovskite solar cell of the present embodiment was obtained (the structure is shown in Figure 1

[0056] Example 2

[0057] The perovskite solar cell and the preparation method thereof of the present embodiment are specifically referred to Example 1, and the difference between the present embodiment and Example 1 is that:

[0058] In the present embodiment, a nickel selenide-doped tungsten oxide conductive film is prepared on the upper surface of the SnO2 electron transport layer in step S3; the rest is referred to Example 1.

[0059] Example 3

[0060] The perovskite solar cell and the preparation method thereof of the present embodiment are specifically referred to Example 1, and the difference between the present embodiment and Example 1 is that:

[0061] In the present embodiment, a nickel selenide-doped tin oxide conductive film is prepared on the upper surface of the SnO2 electron transport layer in step S3; the rest is referred to Example 1.

[0062] Example 4

[0063] The perovskite solar cell and the preparation method thereof of the present embodiment are specifically referred to Example 1, and the difference between the present embodiment and Example 1 is that:

[0064] In the present embodiment, a nickel selenide-doped zinc oxide conductive film is prepared on the upper surface of the SnO2 electron transport layer in step S3; the rest is referred to Example 1.

[0065] Comparative Example 1

[0066] The perovskite solar cell and the preparation method thereof of the present embodiment are specifically referred to Example 1, and the difference between the present embodiment and Example 1 is that:

[0067] In the present embodiment, the titanium oxide conductive film in step S3 is not doped with nickel selenide; the rest is referred to Example 1. ​

[0068] Comparative Example 2

[0069] The perovskite solar cell and the preparation method thereof of the present comparative example are specifically referred to Example 2, and the difference between the present comparative example and Example 2 is that:

[0070] The tungsten oxide conductive film in step S3 of the present comparative example is not doped with nickel selenide; the rest is specifically referred to Example 2.

[0071] Comparative Example 3

[0072] The perovskite solar cell and the preparation method thereof of the present comparative example are specifically referred to Example 3, and the difference between the present comparative example and Example 3 is that:

[0073] The tin oxide conductive film in step S3 of the present comparative example is not doped with nickel selenide; the rest is specifically referred to Example 3.

[0074] Comparative Example 4

[0075] The perovskite solar cell and the preparation method thereof of the present comparative example are specifically referred to Example 4, and the difference between the present comparative example and Example 4 is that:

[0076] The zinc oxide conductive film in step S3 of the present comparative example is not doped with nickel selenide; the rest is specifically referred to Example 4.

[0077] Comparative Example 5

[0078] The perovskite solar cell and the preparation method thereof of the present comparative example are specifically referred to Example 1, and the difference between the present comparative example and Example 1 is that:

[0079] The present comparative example omits step S3 (i.e. the perovskite solar cell structure of the present comparative example does not contain a nickel selenide doped oxide conductive film), and directly proceeds to step S4; the rest is specifically referred to Example 1.

[0080] Performance test

[0081] The perovskite solar cells prepared in Examples 1-4 and Comparative Examples 1-5 were tested for performance under the light irradiation conditions of 25℃, 1000W / m 2 , AM1.5G simulated sunlight, and the performance test results are shown in Table 1. In Table 1, Voc is the open circuit voltage, FF is the fill factor, Jsc is the short circuit current density, and PCE is the photoelectric conversion efficiency.

[0082] Table 1 IV (current-voltage) test results of perovskite solar cells

[0083] Voc (V) FF (%) Jsc(mA / cm 2 )]]> PCE (%) Example 1 1.192 81.65 24.07 23.42 Comparative Example 1 1.175 78.79 23.51 21.76 Example 2 1.189 79.60 24.18 22.89 Comparative Example 2 1.187 79.2 23.35 21.95 Example 3 1.186 80.73 23.65 22.64 Comparative Example 3 1.174 78.96 23.33 21.63 Example 4 1.163 77.65 23.66 21.05 Comparative Example 4 1.157 75.97 23.52 20.67 Comparative Example 5 1.179 78.92 23.20 21.59

[0084] From Table 1, it can be seen that:

[0085] In the present application, the nickel selenide doped conductive oxide film (such as the nickel selenide doped titanium oxide conductive film in Example 1) is prepared between the SnO2 electron transport layer and the perovskite light absorbing layer. Thus, (1) the nickel selenide doped conductive oxide film optimizes the energy level difference between the perovskite light absorbing layer and the SnO2 electron transport layer, reduces the electron transport barrier, accelerates the extraction speed of the photo-generated electrons from the perovskite light absorbing layer to the SnO2 material electron transport layer (ETL), reduces the residence time of the electrons in the perovskite light absorbing layer, thereby reducing the recombination probability; at the same time, it also reduces the migration resistance of the electrons in the SnO2 material ETL, increases the rate of transmission to the metal electrode (such as the silver electrode), directly improves the charge collection efficiency, and the short-circuit current density of the perovskite solar cell is obviously improved compared with the comparative example. (2) Moreover, the added nickel selenide fills the oxygen vacancies of the SnO2 material ETL and passivates the B-site vacancy defects of the perovskite light absorbing layer, which effectively reduces the recombination loss, makes the electron-hole pair separation more sufficient, and thus improves the open-circuit voltage of the perovskite solar cell. (3) Therefore, the high electron transport efficiency reduces the charge transport resistance, reduces the series resistance of the battery, the interface passivation and defect passivation inhibit and reduce the leakage current path, and improve the parallel resistance, so that the fill factor of the perovskite solar cell of the present application is significantly improved, and thus the photoelectric conversion efficiency of the battery is improved (such as the photoelectric conversion efficiency of the battery in Example 1 is improved from 21.76% in Comparative Example 1 to 23.42%).

[0086] Therefore, compared with the prior art or comparative example of CN108389977A, the present application introduces a nickel selenide doped conductive oxide film between the SnO2 material ETL and the perovskite light absorbing layer; this can improve the energy level matching between the SnO2 material ETL and the perovskite light absorbing layer, which is beneficial to the separation and extraction of electrons; and the nickel selenide can interact with the oxygen vacancy defect sites of the SnO2 material ETL, inhibit the ability of the oxygen vacancy defects to capture electrons by passivating the oxygen vacancy defects, improve the electron mobility, and reduce recombination; the nickel atoms in the nickel selenide can also form coordination bonds with the uncoordinated B-site ions on the surface of the perovskite light absorbing layer, further passivate the perovskite interface, effectively passivate the dangling bonds and defect states at the interface, further reduce recombination to improve battery performance.

[0087] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to these embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the present application.

[0088] The technical solutions provided by the present application are described in detail above, and the principles and implementation manners of the present application are described by applying specific examples. The above description of the examples is only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manners and application ranges will be changed, and the above description should not be understood as a limitation on the present application.

Claims

1. A perovskite solar cell, characterized in that It includes a substrate, an electron transport layer, a perovskite light absorption layer, a hole transport layer and a metal electrode stacked in sequence from bottom to top; Wherein, the electron transport layer is a tin oxide electron transport layer; a nickel selenide-doped conductive oxide film is also provided between the tin oxide electron transport layer and the perovskite light absorption layer, and the doping concentration of the nickel selenide in the conductive oxide film is controlled at 0.01-5 mmol / L.

2. A perovskite solar cell according to claim 1, characterized in that: The doping concentration of nickel selenide in the conductive oxide film is 0.5 mmol / L.

3. The perovskite solar cell according to claim 1, wherein: The thickness of the nickel selenide-doped conductive oxide film is 10-200 nm.

4. A perovskite solar cell according to any one of claims 1 to 3, characterized in that: The thickness of the nickel selenide-doped conductive oxide film is 20 nm.

5. A perovskite solar cell according to any one of claims 1 to 3, characterized in that: The conductive oxide film is made of at least one of tungsten oxide, zinc oxide, tin oxide, and titanium oxide; The A-site ions in the ABX3 material of the perovskite light-absorbing layer are one or more of cesium ions, methylammonium ions, potassium ions, rubidium ions, and formamidine ions; the B-site ions are one or more of lead ions, tin ions, calcium ions, germanium ions, copper ions, zinc ions, and gallium ions; and the X-site ions are one or more of iodide ions, bromide ions, chloride ions, fluoride ions, and thiocyanate ions.

6. A perovskite solar cell according to any one of claims 1 to 3, characterized in that: The substrate is indium tin oxide conductive glass; the perovskite light absorbing layer is Cs 0.05 (FA 0.9 MA 0.1 ) 0.95 Pb(I 0.9 Br 0.1 )3; the material of the hole transport layer is 4-(3,6-dimethyl-9H-carbazole-9-yl)butylphosphonic acid; the metal electrode is a silver electrode.

7. The method for preparing a perovskite solar cell according to any one of claims 1 to 6, characterized in that: It comprises the following preparation steps: S1, pre-treating the substrate; S2. preparing a tin oxide electron transport layer on one surface of the pretreated substrate; S3, forming a nickel selenide-doped conductive oxide film on a surface of the tin oxide electron transport layer away from the substrate; S4, preparing a perovskite light absorbing layer on a surface of the nickel selenide-doped conductive oxide film away from the tin oxide electron transport layer; S5, forming a hole transport layer on a surface of the perovskite light absorbing layer away from the nickel selenide-doped conductive oxide film; S6. Prepare a metal electrode on a surface of the hole transport layer away from the perovskite light absorbing layer to obtain the perovskite solar cell.

8. The method for preparing a perovskite solar cell according to claim 7, wherein: In step S3, the nickel selenide-doped conductive oxide film is prepared by spin coating, blade coating, spray coating, chemical bath deposition, sputtering, atomic deposition or evaporation.

9. The method for preparing a perovskite solar cell according to claim 7, wherein: In step S1, the pretreatment includes: cleaning the substrate with acetone, anhydrous ethanol and deionized water in sequence, then drying it with dry nitrogen, and then treating it with ultraviolet light and ozone to obtain a clean substrate with a hydrophilic surface.

10. A stacked solar cell, characterized in that: It comprises a perovskite solar cell according to any one of claims 1 to 6.

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