Perovskite solar cell containing Al-doped ZnO nanorod arrays and preparation method thereof

Abstract

The present invention discloses a perovskite solar cell containing an Al-doped ZnO nanorod array and a preparation method thereof. The cell includes a transparent conductive substrate layer, an electron transport layer, a metal halide perovskite light-absorbing layer, and a back electrode layer which are sequentially arranged from bottom to top. The electron transport layer is composed of a seed layer, an Al-doped ZnO nanorod array layer, and a passivation layer from bottom to top. The preparation method includes preparing a seed layer on the transparent conductive substrate layer, preparing an Al-doped ZnO nanorod array layer on the seed layer by electrochemical deposition, controlling the voltage at -1.45 V to -1.55 V, keeping the deposition temperature at 80 °C ± 3 °C, controlling the deposition time at 10 min to 30 min, and then preparing a passivation layer, a metal halide perovskite light-absorbing layer, and a back electrode layer to obtain the cell. Compared with the prior art, the open-circuit voltage, short-circuit current density, fill factor, and photoelectric conversion efficiency of the cell are all greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and relates to a perovskite solar cell containing an Al-doped ZnO nanorod array and a preparation method thereof, and particularly relates to a metal halide perovskite solar cell using an Al-doped ZnO nanorod array as an electron transport layer and a preparation method thereof. Background Art

[0002] In the past decade, perovskite solar cells (PSCs) have developed rapidly and are considered to be the most promising solar cells to compete with crystalline silicon solar cells. Since 2009, the power conversion efficiency (PCE) of organic-inorganic hybrid PSCs has increased from 3.8% to 25.5%. Although the PCE of all-inorganic PSCs is inferior to the former, they have received great attention due to their higher stability. The raw materials of PSCs are widely sourced and inexpensive, the preparation process is simple, and they can be prepared on flexible substrates, making them the most promising emerging photovoltaic devices at present.

[0003] The electron transport layer material is one of the key materials of PSCs. The most commonly used is TiO2, but it has strong ultraviolet photocatalytic activity, and the generated oxygen or hydroxyl radicals will damage the organic chemical bonds of the perovskite light absorption layer, affecting long-term stability; TiO2 requires high-temperature sintering above 500 °C and has a low electron mobility. ZnO has semiconductor properties similar to TiO2, can be prepared at low temperature, and it is easy to obtain one-dimensional nanostructure arrays with rich morphologies. Replacing particulate TiO2 with a ZnO nanorod array as the electron transport layer material has the advantages of single-crystal linear electron transport, increasing electron transport channels, light diffraction, etc., and at the same time plays the role of accelerating electron transport and light trapping; in addition, the ZnO nanorod array can effectively buffer bending stress / strain and improve the mechanical flexibility of the device. However, the carrier concentration of the undoped ZnO nanorod array is relatively low, and its conductivity is still relatively low, resulting in the electrons generated by the light absorption layer not being able to be transmitted to the external circuit in time, thus resulting in a low short-circuit current density; in addition, the hydroxyl groups and oxygen vacancies present on the ZnO surface are weakly basic and will become non-radiative recombination centers for carriers, resulting in a decrease in the power conversion efficiency and stability of the battery. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a perovskite solar cell containing an Al-doped ZnO nanorod array and a preparation method thereof, which can improve the conductivity, stability, and output performance of the battery, and has no destructive effect on the perovskite material, and exhibits excellent thermal stability and water-oxygen stability in the natural environment.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions.

[0006] A perovskite solar cell containing an Al-doped ZnO nanorod array, wherein the perovskite solar cell comprises a transparent conductive substrate layer, an electron transport layer, a metal halide perovskite light absorption layer, and a back electrode layer which are sequentially arranged from bottom to top, and the electron transport layer is composed of a seed layer, an Al-doped ZnO nanorod array layer, and a passivation layer from bottom to top.

[0007] For the above-mentioned perovskite solar cell containing an Al-doped ZnO nanorod array, preferably, the transparent conductive substrate layer is ITO conductive glass, FTO conductive glass, AZO conductive glass, or a flexible polymer substrate, and / or, the seed layer is a SnO2 seed layer, the passivation layer is a SnO2 passivation layer, and / or, the back electrode layer is a carbon electrode, a silver electrode, or a gold electrode, and / or, the metal halide perovskite light absorption layer is an organic-inorganic hybrid perovskite light absorption layer or an all-inorganic perovskite light absorption layer. The organic-inorganic hybrid perovskite light absorption layer includes a FAPbI3 perovskite light absorption layer or a MAPbI3 perovskite light absorption layer, and the all-inorganic perovskite light absorption layer includes a CsPbBr3 perovskite light absorption layer, a CsPbBr2I perovskite light absorption layer, a CsPbBrI2 perovskite light absorption layer, or a CsPbI3 perovskite light absorption layer.

[0008] As a general technical concept, the present invention also provides a preparation method for the above-mentioned perovskite solar cell containing an Al-doped ZnO nanorod array, comprising the following steps:

[0009] S1. Prepare a seed layer on the transparent conductive substrate layer;

[0010] S2. Prepare an Al-doped ZnO nanorod array layer on the seed layer. The preparation process includes: adding a soluble salt of zinc into water to obtain a zinc salt solution, adding a soluble salt of aluminum into water to obtain an aluminum salt solution, adding the aluminum salt solution into the zinc salt solution, controlling the atomic ratio of Al to Zn to be 0.75-1.25:100, stirring to obtain a mixed solution, then heating and raising the temperature to 80°C ± 3°C, using an inert electrode as the positive electrode and the transparent conductive substrate layer on which the seed layer is deposited as the negative electrode for electrochemical deposition, controlling the voltage at -1.45V to -1.55V, keeping the deposition temperature at 80°C ± 3°C, controlling the deposition time at 10 min to 30 min, and performing post-deposition heat treatment to obtain an Al-doped ZnO nanorod array layer on the seed layer;

[0011] S3. Prepare a passivation layer on the Al-doped ZnO nanorod array layer;

[0012] S4. Prepare a metal halide perovskite light absorption layer on the passivation layer;

[0013] S5. Prepare a back electrode layer on the metal halide perovskite light-absorbing layer to obtain a perovskite solar cell containing an Al-doped ZnO nanorod array.

[0014] For the preparation method of the above perovskite solar cell containing an Al-doped ZnO nanorod array, preferably, in step S1, the seed layer is a SnO2 seed layer, and the preparation method of the SnO2 seed layer is as follows: Dissolve a soluble salt of tin in absolute ethanol to obtain an ethanol solution of the tin salt. The concentration of the tin salt in the ethanol solution of the tin salt is controlled at 0.15 mol / L to 0.25 mol / L, stir at room temperature for 85 min to 95 min, spin-coat on the transparent conductive substrate layer, the spin-coating speed is 2500 rpm to 3500 rpm, the spin-coating time is 25 s to 35 s, and then perform heat treatment. The temperature of the heat treatment is 345 °C to 355 °C, and the time of the heat treatment is 55 min to 95 min.

[0015] For the preparation method of the above perovskite solar cell containing an Al-doped ZnO nanorod array, preferably, in step S3, the passivation layer is a SnO2 passivation layer, and the preparation method of the SnO2 passivation layer is as follows: Dissolve a soluble salt of tin in absolute ethanol to obtain an ethanol solution of the tin salt. The concentration of the tin salt in the ethanol solution of the tin salt is controlled at 0.15 mol / L to 0.25 mol / L, stir at room temperature for 85 min to 95 min, spin-coat on the surface of the Al-doped ZnO nanorod array layer, the spin-coating speed is 4500 rpm to 5500 rpm, the spin-coating time is 25 s to 35 s, and then perform heat treatment. The temperature of the heat treatment is 345 °C to 355 °C, and the time of the heat treatment is 25 min to 65 min.

[0016] For the preparation method of the above perovskite solar cell containing an Al-doped ZnO nanorod array, preferably, in step S2, the concentration of the zinc salt solution is 0.0025 mol / L to 0.0035 mol / L, the concentration of the aluminum salt solution is 0.0025 mol / L to 0.0035 mol / L, the soluble salt of zinc is zinc nitrate hexahydrate, and the soluble salt of aluminum is aluminum nitrate nonahydrate.

[0017] For the preparation method of the above perovskite solar cell containing an Al-doped ZnO nanorod array, preferably, in step S2, the stirring time is 30 min to 35 min.

[0018] For the preparation method of the above perovskite solar cell containing an Al-doped ZnO nanorod array, preferably, in step S2, the electrochemical deposition is carried out in a Hull cell, the inert electrode is platinum titanium mesh or platinum, and the distance between the positive electrode and the negative electrode is 2 cm to 3 cm.

[0019] For the preparation method of the perovskite solar cell containing an Al-doped ZnO nanorod array, preferably, in step S2, the temperature of the heat treatment is 450°C ± 3°C, the time of the heat treatment is 30 min to 45 min, and the atmosphere of the heat treatment is air.

[0020] In the present invention, a hole transport layer can be added or not added between the metal halide perovskite light-absorbing layer and the back electrode layer, which can be selected according to actual needs.

[0021] In the present invention, the thickness of each layer of the battery can be within the conventional thickness range and can be set according to the actual needs of the battery, so it is not limited. Generally, it can be set in the following range: the transparent conductive substrate layer is 500 nm - 600 nm, the seed crystal layer is 80 nm - 120 nm, the Al-doped ZnO nanorod array layer is 300 nm - 500 nm, the passivation layer is 50 nm - 80 nm, the metal halide perovskite light-absorbing layer is 500 nm - 1000 nm, and the back electrode layer is 800 - 1200 nm, but it is not limited thereto.

[0022] Compared with the prior art, the advantages of the present invention are as follows:

[0023] The present invention provides a perovskite solar cell containing an Al-doped ZnO nanorod array and a preparation method thereof. This method not only requires Al doping of ZnO nanorods to change their surface properties, but also uses tin dioxide (SnO2) as a passivation layer to avoid direct contact between ZnO nanorods and the perovskite thin film. The two are carried out simultaneously to solve the existing problems. The Al-doped ZnO nanorod array prepared by this method has the advantages of low cost, large-scale preparation, and controllable morphology and thickness of the nanorods. The obtained ZnO nanorods have high electron mobility, high conductivity, and good stability. The output performance of the solar cell prepared with these nanorods has been greatly improved. The battery preparation method of the present invention can improve the conductivity, stability, and output performance of the battery by using these ZnO nanorods and specific process parameters, and there is no destructive effect on the perovskite material, showing excellent thermal stability and water and oxygen stability in the natural environment.

[0024] The present invention realizes the growth of Al-doped ZnO nanorod arrays by electrodeposition method, greatly improves their conductivity, and obtains the process control rules. The size, morphology and thickness of the Al-doped ZnO nanorod arrays are controlled by the SnO2 seed layer and electrodeposition process parameters (including the concentration of the electrodeposition solution, the distance between the positive and negative electrodes, the electrodeposition temperature, the electrodeposition time, etc.). The conductivity of the Al-doped ZnO nanorod arrays is controlled by the Al doping amount. The SnO2 passivation layer is used to prevent the direct contact between the metal halide perovskite light-absorbing layer and the surface of the Al-doped ZnO nanorod arrays. A method for preparing an Al-doped ZnO nanostructure array with a special morphology by a simple preparation process and large-area growth at low cost is provided. It has an excellent surface texture light trapping effect and can improve the light trapping efficiency of solar cells. Compared with the traditional TiO2 electron transport layer, the electron mobility of the Al-doped ZnO nanorod array electron layer is greatly improved, the conductivity is significantly enhanced, and the thermal stability is greatly improved. Compared with the traditional SnO2 used as the electron transport layer, the Al-doped ZnO nanorod array electron transport layer has significantly improved the photoelectric conversion efficiency, open circuit voltage and short circuit current density, greatly improving the performance of the battery. Description of the Drawings

[0025] Figure 1 Fig. is a schematic three-dimensional structure diagram of a perovskite solar cell containing an Al-doped ZnO nanorod array according to Embodiment 1 of the present invention.

[0026] Figure 2 Fig. is a schematic cross-sectional structure diagram of a perovskite solar cell containing an Al-doped ZnO nanorod array according to Embodiment 1 of the present invention.

[0027] Figure 3 Fig. is a SEM image of an Al-doped ZnO nanorod array prepared in Embodiment 1 of the present invention.

[0028] Figure 4 Fig. is a J-V curve diagram of a perovskite solar cell containing an Al-doped ZnO nanorod array prepared in Embodiment 1 of the present invention.

[0029] Figure 5 Fig. is a J-V curve diagram of a CsPbBr3 perovskite solar cell with SnO2 as the electron transport layer in Comparative Example 1.

[0030] Figure 6 Fig. is a J-V curve diagram of an undoped ZnO nanorod-based CsPbBr3 perovskite solar cell.

[0031] Legend:

[0032] 1. Transparent conductive substrate layer; 2. Seed layer; 3. Al-doped ZnO nanorod array layer; 4. Passivation layer; 5. Metal halide perovskite light-absorbing layer; 6. Back electrode layer. Detailed implementation mode

[0033] The present invention will be further described below in conjunction with the accompanying drawings of the specification and specific preferred embodiments, but the protection scope of the present invention is not limited thereby. The materials and instruments used in the following embodiments are all commercially available.

[0034] Example 1

[0035] A perovskite solar cell containing an Al-doped ZnO nanorod array of the present invention, as Figure 1 and Figure 2 shown, the perovskite solar cell includes a transparent conductive substrate layer 1, an electron transport layer, a metal halide perovskite light absorption layer 5, and a back electrode layer 6 arranged in sequence from bottom to top. The electron transport layer is composed of a seed layer 2, an Al-doped ZnO nanorod array layer 3, and a passivation layer 4 from bottom to top.

[0036] In this embodiment, the transparent conductive substrate layer 1 is an FTO conductive glass layer, the seed layer 2 is a SnO2 seed layer, the passivation layer 4 is a SnO2 passivation layer, the back electrode layer 6 is a carbon electrode, and the metal halide perovskite light absorption layer 5 is a CsPbBr3 perovskite thin film layer.

[0037] A preparation method of a perovskite solar cell containing an Al-doped ZnO nanorod array of this embodiment includes the following steps:

[0038] S1. Cleaning the FTO transparent conductive glass

[0039] Successively ultrasonic clean the FTO conductive glass (commercially available) with glass cleaner, deionized water, acetone, isopropanol, and absolute ethanol for 30 minutes each, bake at 80 °C for 20 minutes, and then clean the FTO conductive glass with a UV-ozone cleaner for 25 minutes.

[0040] S2. Preparing the SnO2 seed layer

[0041] Take 0.1896 g of anhydrous stannous chloride and dissolve it in 5 mL of absolute ethanol. Stir it open at room temperature for 90 minutes without aging. Spin-coat the ethanol solution of stannous chloride onto the cleaned FTO conductive glass at 3000 rpm for 30 s. Place it in a muffle furnace and heat-treat it at 350 °C for 60 minutes to obtain the SnO2 seed layer.

[0042] S3. Preparing the Al-doped ZnO nanorod array layer 3

[0043] Take 1.1254 g of aluminum nitrate nonahydrate (Al(NO3)3·9H2O) and dissolve it in 1000 mL of deionized water. Stir at room temperature for 30 min to obtain an aluminum nitrate solution; take 0.4463 g of zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and dissolve it in 500 mL of deionized water to obtain a zinc nitrate solution. Take 5 mL of the aluminum nitrate solution and add it to the zinc nitrate solution. Control the Al / Zn atomic ratio to 1.00 at.%, and stir at room temperature for 30 min to obtain a mixed solution (i.e., the electrodeposition solution). Add the electrodeposition solution to a Hull cell, heat it up to 80 °C, place the FTO conductive glass coated with a SnO2 seed layer at the negative electrode, and place a platinum titanium mesh (inert electrode) at the positive electrode. The distance between the positive and negative electrodes is 2 cm, control the voltage at -1.5 V, and perform electrochemical deposition for 15 min, while maintaining the temperature at 80 °C during the deposition. After the deposition is completed, put the product into a muffle furnace and heat-treat it at 450 °C for 30 min. The atmosphere for the heat treatment is air, and then let it cool down with the furnace to obtain an Al-doped ZnO nanorod array layer 3. The SEM test results are as Figure 3 shown.

[0044] S4. Preparation of SnO2 Passivation Layer

[0045] Take 0.1896 g of anhydrous stannous chloride and dissolve it in 5 mL of anhydrous ethanol. Stir it open at room temperature for 90 min without aging. Spin-coat the ethanol solution of stannous chloride onto the Al-doped ZnO nanorod array layer 3 at 5000 rpm for 30 s, place it in a muffle furnace, and heat-treat it at 350 °C for 30 min to obtain an SnO2 passivation layer.

[0046] S5. Preparation of CsPbBr3 All-Inorganic Perovskite Thin Film

[0047] S5.1 Dissolve PbBr2 in N,N-dimethylformamide (DMF) to prepare a DMF solution with a concentration of 1.0 mol / L PbBr2; dissolve CsBr in methanol to prepare a methanol solution with a concentration of 0.07 mol / L CsBr.

[0048] S5.2 Spin-coat the PbBr2 solution on the SnO2 passivation layer at 2000 rpm for 30 s, heat-treat it at 90 °C for 30 min, and then dynamically spin-coat (i.e., drip and spin-coat simultaneously) the CsBr solution at 2000 rpm for 30 s. Heat-treat it at 250 °C for 5 min. Repeat this step (starting from spin-coating the CsBr solution) 6 times to obtain a CsPbBr3 perovskite thin film layer.

[0049] S6. Preparation of Carbon Electrode Layer

[0050] The carbon electrode was prepared by the doctor blade method. After the carbon electrode was prepared, it was placed on a hot stage at 120 °C and dried for 20 min. Finally, the complete battery device FTO / SnO2 / AZO NRA / SnO2 / CsPbBr3 / C was obtained.

[0051] The perovskite solar cell containing Al-doped ZnO nanorod arrays prepared in this example was subjected to J-V testing, and the test results are as Figure 4 shown. It can be seen from Figure 4 that in Example 1, the open-circuit voltage (V oc ) was 1.38 V, the short-circuit current density (J sc ) was 6.83 mA / cm 2 , the fill factor (FF) was 65%, and the power conversion efficiency (PCE) was 6.09%, showing excellent photovoltaic performance.

[0052] Comparative Example 1

[0053] A CsPbBr3 all-inorganic perovskite solar cell using SnO2 as the electron transport layer, and the preparation method includes the following steps:

[0054] (1) Cleaning the FTO transparent conductive glass: the same as step S1 in Example 1.

[0055] (2) Preparing the SnO2 electron transport layer: Dissolve 0.1896 g of anhydrous stannous chloride in 5 mL of anhydrous ethanol, stir it open at room temperature for 90 min without aging. Spin-coat the stannous chloride solution onto the cleaned FTO conductive glass at 3000 rpm for 30 s, and heat-treat it on a heating stage at 200 °C for 120 min. This heat-treatment temperature is the optimal heat-treatment temperature determined according to the best experimental results.

[0056] (3) Preparing the CsPbBr3 all-inorganic perovskite thin film: the same as step S5 in Example 1.

[0057] The all-inorganic perovskite solar cell prepared in this comparative example was subjected to J-V testing, and the test results are as Figure 5 shown. It can be seen from Figure 5 that in Comparative Example 1, the open-circuit voltage was 1.14 V, the short-circuit current density was 6.93 mA / cm 2 , the fill factor was 60%, and the power conversion efficiency was 4.83%. It can be seen from this that the performance of Example 1 is better than that of Comparative Example 1. It shows that the effect of Al-doped ZnO nanorod arrays as the electron transport layer is better than that of the traditional SnO2 electron transport layer.

[0058] Comparative Example 2

[0059] A preparation method of an undoped ZnO nanorod array-based CsPbBr3 perovskite solar cell is basically the same as that of Example 1, except that the ZnO nanorod array is not doped with Al.

[0060] The CsPbBr3 all-inorganic perovskite solar cell using ZnO nanorods prepared under this condition as the electron transport layer is subjected to J-V testing, as Figure 6 shown. As Figure 6 can be seen, in Comparative Example 2, the open-circuit voltage is 1.25 V, the short-circuit current density is 5.81 mA / cm 2 , the fill factor is 63%, and the photoelectric conversion efficiency is 4.6%. From this, it can be seen that the cell performance of Example 1 is superior to that of Comparative Example 2. This shows that the Al-doped ZnO nanorod array can overall improve the performance of the ZnO nanorod array as the electron transport layer.

[0061] The above is only a preferred embodiment of the present invention and does not impose any form of limitation on the present invention. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A preparation method of a perovskite solar cell containing Al-doped ZnO nanorod arrays, characterized in that, It includes the following steps: S1. Prepare a seed layer (2) on a transparent conductive substrate layer (1); S2. Prepare an Al-doped ZnO nanorod array layer (3) on the seed layer (2). The preparation process includes: adding a soluble zinc salt into water to obtain a zinc salt solution, adding a soluble aluminum salt into water to obtain an aluminum salt solution, adding the aluminum salt solution into the zinc salt solution, controlling the atomic ratio of Al to Zn to be 0.75 - 1.25:100, stirring to obtain a mixed solution, then heating up to 80°C ± 3°C, using an inert electrode as the positive electrode and the transparent conductive substrate layer (1) on which the seed layer (2) is deposited as the negative electrode for electrochemical deposition, controlling the voltage at -1.45V to -1.55V, keeping the deposition temperature at 80°C ± 3°C, controlling the deposition time at 10 min to 30 min, and performing post-deposition heat treatment to obtain the Al-doped ZnO nanorod array layer (3) on the seed layer (2); S3. Prepare a passivation layer (4) on the Al-doped ZnO nanorod array layer (3); S4. Prepare a metal halide perovskite light-absorbing layer (5) on the passivation layer (4); S5. Prepare a back electrode layer (6) on the metal halide perovskite light-absorbing layer (5) to obtain a perovskite solar cell containing an Al-doped ZnO nanorod array; In step S1, the seed layer (2) is a SnO2 seed layer. The preparation method of the SnO2 seed layer is: dissolving a soluble tin salt in absolute ethanol to obtain an ethanol solution of the tin salt, controlling the concentration of the tin salt in the ethanol solution of the tin salt at 0.15 mol / L to 0.25 mol / L, stirring at room temperature for 85 min to 95 min, spin-coating on the transparent conductive substrate layer (1), the spin-coating speed is 2500 rpm to 3500 rpm, the spin-coating time is 25 s to 35 s, and then performing heat treatment, the heat treatment temperature is 345°C to 355°C, and the heat treatment time is 55 min to 95 min; The perovskite solar cell includes a transparent conductive substrate layer (1), an electron transport layer, a metal halide perovskite light-absorbing layer (5), and a back electrode layer (6) arranged in sequence from bottom to top. The electron transport layer is composed of a seed layer (2), an Al-doped ZnO nanorod array layer (3), and a passivation layer (4) from bottom to top; The transparent conductive substrate layer (1) is ITO conductive glass, FTO conductive glass, AZO conductive glass, or a flexible polymer substrate. The seed layer (2) is a SnO2 seed layer. The passivation layer (4) is a SnO2 passivation layer. The back electrode layer (6) is a carbon electrode, a silver electrode, or a gold electrode. The metal halide perovskite light-absorbing layer (5) is an organic-inorganic hybrid perovskite light-absorbing layer or an all-inorganic perovskite light-absorbing layer. The organic-inorganic hybrid perovskite light-absorbing layer includes an FAPbI3 perovskite light-absorbing layer or a MAPbI3 perovskite light-absorbing layer. The all-inorganic perovskite light-absorbing layer includes a CsPbBr3 perovskite light-absorbing layer, a CsPbBr2I perovskite light-absorbing layer, a CsPbBrI2 perovskite light-absorbing layer, or a CsPbI3 perovskite light-absorbing layer.

2. The preparation method of the perovskite solar cell containing an Al-doped ZnO nanorod array according to claim 1, characterized in that In step S3, the passivation layer (4) is a SnO2 passivation layer, and the preparation method of the SnO2 passivation layer is as follows: Dissolve the soluble salt of tin in absolute ethanol to obtain an ethanol solution of tin salt. The concentration of tin salt in the ethanol solution of tin salt is controlled at 0.15 mol / L to 0.25 mol / L, stir at room temperature for 85 min to 95 min, spin-coat on the surface of the Al-doped ZnO nanorod array layer (3), the spin-coating speed is 4500 rpm to 5500 rpm, the spin-coating time is 25 s to 35 s, and then perform heat treatment. The temperature of the heat treatment is 345 °C to 355 °C, and the time of the heat treatment is 25 min to 65 min.

3. The preparation method of the perovskite solar cell containing the Al-doped ZnO nanorod array according to claim 1 or 2, characterized in that, In step S2, the concentration of the zinc salt solution is 0.0025 mol / L to 0.0035 mol / L, the concentration of the aluminum salt solution is 0.0025 mol / L to 0.0035 mol / L, the soluble salt of zinc is zinc nitrate hexahydrate, and the soluble salt of aluminum is aluminum nitrate nonahydrate.

4. The preparation method of the perovskite solar cell containing an Al-doped ZnO nanorod array according to claim 1 or 2, characterized in that, In step S2, the stirring time is 30 min to 35 min.

5. The preparation method of the perovskite solar cell containing an Al-doped ZnO nanorod array according to claim 1 or 2, characterized in that, In step S2, the electrochemical deposition is carried out in a Hull cell. The inert electrode is platinum titanium mesh or platinum, and the distance between the positive electrode and the negative electrode is 2 cm to 3 cm.

6. The preparation method of the perovskite solar cell containing an Al-doped ZnO nanorod array according to claim 1 or 2, characterized in that, In step S2, the temperature of the heat treatment is 450 °C ± 3 °C, the time of the heat treatment is 30 min to 45 min, and the atmosphere of the heat treatment is air.

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