A solar cell with addition of mwcnt:nio in spiro-ome tad and a method for manufacturing the same

Abstract

The application discloses a solar cell with MWCNT:NiO added in spiro-OMeTAD and a preparation method thereof, and the preparation method comprises the following steps: (1) cleaning and blowing dry an ITO substrate; (2) preparing a SnO2-KCl solution; and spin-coating the SnO2-KCl solution on the ITO glass; (3) spin-coating an Al2O3 precursor solution on the SnO2-KCl layer; (4) spin-coating a perovskite precursor solution on the Al2O3 layer; (5) spin-coating a spiro-OMeTAD+MWCNT:NiO dispersion liquid on the perovskite layer; and (6) vacuum evaporating a gold electrode. The application avoids high-temperature treatment in the preparation process of the solar cell in the prior art, thereby reducing production cost, improving photoelectric conversion efficiency of the solar cell, and being suitable for large-scale industrialized production in a roll-to-roll mode.

Description

Technical Field

[0001] This invention belongs to the fields of materials chemistry and biology, and specifically relates to a solar cell with MWCNT:NiO added to spiro-OMeTAD and its preparation method. Background Technology

[0002] With the development of science and technology and the progress of society, environmental pollution and the energy crisis remain two major problems that humanity urgently needs to solve. Solar energy, as a clean and renewable energy source, has enormous reserves that are inexhaustible and have excellent application prospects. Solar cells, as a light-to-electricity conversion element, can convert solar radiation energy into electrical energy, which is one of the important ways to solve environmental pollution and the energy crisis. In recent years, novel perovskite solar cells, with their advantages of high efficiency, low cost, and simple fabrication processes, have attracted widespread attention. Perovskite materials are abundant and easy to prepare, and the cell assembly process has low costs, thus showing great commercial application potential. Summary of the Invention

[0003] The purpose of this invention is to provide a solar cell with nickel oxide quantum dot-modified multi-walled carbon nanotubes (MWCNT:NiO) added to spiro-OMeTAD and its preparation method. This invention overcomes the instability and deliquescence of the hole transport layer in previous perovskite solar cells, and also provides a new approach for the rapid transfer and extraction of charge in the hole transport layer.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A method for fabricating a perovskite solar cell with spiro-OMeTAD+MWCNT:NiO as the hole transport layer is as follows:

[0006] (1) The ITO (indium tin oxide) substrate was ultrasonically cleaned sequentially with deionized water, anhydrous ethanol and acetone, and then the ITO substrate was dried with nitrogen and subjected to ultraviolet treatment.

[0007] (2) Prepare SnO2-KCl solution in air; then spin-coat the obtained SnO2-KCl solution onto ITO glass, anneal after spin-coating, and finally perform ultraviolet treatment to obtain ITO / SnO2-KCl sample;

[0008] (3) Prepare an Al2O3 precursor solution; then spin-coat the Al2O3 precursor solution onto the sample from step (2), and anneal after spin-coating to obtain an ITO / SnO2-KCl / Al2O3 sample;

[0009] (4) The ITO / SnO2-KCl / Al2O3 sample obtained in step (3) was spin-coated with perovskite precursor solution under nitrogen protection, and then annealed to obtain ITO / SnO2-KCl / Al2O3 / perovskite sample.

[0010] (4) The ITO / SnO2-KCl / Al2O3 sample obtained in step (3) was spin-coated with perovskite precursor solution under nitrogen protection, and then annealed to obtain ITO / SnO2-KCl / Al2O3 / perovskite sample.

[0011] (5) Spin-coating the sample obtained in step (4) with spiro-OMeTAD+MWCNT:NiO dispersion and air-drying it naturally to obtain ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO sample; The preparation process of spiro-OMeTAD+MWCNT:NiO dispersion is as follows: MWCNT:NiO is added to chlorobenzene and ultrasonically dispersed and then magnetically stirred to obtain 0.01mg / mL~0.02mg / mL MWCNT:NiO chlorobenzene dispersion. spiro-OMeTAD powder is added to MWCNT:NiO chlorobenzene dispersion, and then lithium bis(trifluoromethanesulfonylimide) and 4-tert-butylpyridine are added. Stir for 10h~15h to obtain the sample.

[0012] (6) Vacuum evaporation of gold electrodes is performed on the sample obtained in step (5) to finally obtain a solar cell with the structure ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO / Au.

[0013] Preferably, in step (2), the SnO2-KCl solution is prepared as follows: potassium chloride is dissolved in deionized water to prepare a KCl solution with a concentration of 5 mg / ml. Then, a SnO2 hydrocolloid solution with a concentration of 15 wt% and a KCl solution with a volume ratio of 5 mg / ml are mixed at a volume ratio of 2:1 to prepare a SnO2-KCl solution. In step (2), annealing refers to annealing at 100°C for 5 minutes and then annealing at 150°C for 10 minutes.

[0014] Preferably, in step (3), the preparation process of the Al2O3 precursor solution is as follows: the Al2O3 precursor solution is obtained by diluting the 20 wt% Al2O3 isopropanol solution and isopropanol at a volume ratio of 1:15. In step (3), annealing refers to annealing at 120°C for 5 minutes and then annealing at 200°C for 20 minutes.

[0015] Preferably, in step (4), the perovskite precursor solution is specifically Cs 0.05 (FA 0.85 MA 0.15) 0.95 Pb(I 0.85 Br 0.15 3. Perovskite precursor solution, the specific preparation process is as follows: CsI, FAI, MAI, PbI2 and PbBr2 are dissolved in a mixed solution of DMF and DMSO with a volume ratio of 8.5:1.5 in a molar ratio of 0.05:0.81:0.14:0.78:0.22. 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 The volume ratio of 3 moles is 1.4 mol / L, and then the mixture is stirred for 10 h to 15 h to obtain a perovskite precursor solution; in step (4), annealing means annealing at 90℃ for 5 minutes and then annealing at 120℃ for 10 minutes.

[0016] Preferably, in step (5), the concentration of MWCNT:NiO chlorobenzene dispersion is 0.015 mg / mL, the ultrasonic power is 800 W, the ultrasonic time is 0.5 h to 1.5 h, the magnetic stirring speed is 3000 rpm, and the stirring time is 1.5 h to 2.5 h.

[0017] The preparation process of spiro-OMeTAD+MWCNT:NiO dispersion is as follows: 72.5 mg of spiro-OMeTAD powder is weighed, and 1 mL of MWCNT:NiO chlorobenzene dispersion, 18 μL of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 28.5 μL of 4-tert-butylpyridine are added. The mixture is stirred for 12 h to obtain spiro-OMeTAD+MWCNT:NiO dispersion.

[0018] The preparation process of NiO-modified multi-walled carbon nanotube powder (MWCNT:NiO) is as follows: Ni-modified multi-walled carbon nanotube powder (MWCNT:Ni) with an outer diameter of 10-20 nm and a length of 10-30 μm (carbon nanotube content >38 wt%) is placed in a muffle furnace and heated in air to 200±10℃ and held for 25~35 minutes to obtain NiO-modified multi-walled carbon nanotube powder (MWCNT:NiO).

[0019] The perovskite solar cell prepared by the above method with spiro-OMeTAD+MWCNT:NiO as the hole transport layer has the following characteristics: SnO2-KCl layer thickness is 40 nm, Al2O3 layer thickness is 20 nm, perovskite layer thickness is 450 nm, spiro-OMeTAD+MWCNT:NiO layer thickness is 140 nm, and gold electrode thickness is 80 nm.

[0020] Compared with existing methods, the method of this invention can maximize the performance of solar cells under the same conditions, avoid the high-temperature treatment in the previous solar cell manufacturing process, thereby reducing production costs, and also improve the photoelectric conversion efficiency of solar cells, making it suitable for large-scale industrial production of roll-to-roll. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the battery structure of the present invention;

[0022] Figure 2 Surface scanning electron microscope (SEM) images of spiro-OMeTAD and spiro-OMeTAD+MWCNT:NiO thin films prepared in Example 1;

[0023] Figure 3 The X-ray diffraction (XRD) pattern of MWCNT:NiO obtained in Example 1;

[0024] Figure 4 The current density-voltage ratio of the solar cells prepared in Example 1 for ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD / Au and ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO / Au is calculated. J -V) curve;

[0025] Figure 5 Stability testing of the ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD / Au and ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO / Au batteries prepared in Example 1;

[0026] Figure 6 Water contact angle tests were performed on spiro-OMeTAD and spiro-OMeTAD+MWCNT:NiO films. Detailed Implementation

[0027] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the scope of protection of the present invention is not limited thereto.

[0028] Example 1

[0029] A method for fabricating a perovskite solar cell with spiro-OMeTAD+MWCNT:NiO as the hole transport layer is as follows:

[0030] (1) Prepare SnO2-KCl solution in air: Dissolve 5 mg of potassium chloride in 1 ml of deionized water to prepare a KCl solution with a mass concentration of 5 mg / ml. Then dilute the SnO2 hydrocolloid solution (purchased from Alfa Aesar) with the prepared KCl solution at a volume ratio of 2:1 to prepare SnO2-KCl solution.

[0031] (2) Preparation of Al2O3 precursor solution: The Al2O3 precursor solution is obtained by diluting a 20 wt% Al2O3 isopropanol solution (nanoparticle size <50 nm, purchased from Sigma-Aldrich) and isopropanol at a volume ratio of 1:15.

[0032] (3) Preparation of Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 3) Perovskite precursor solution: CsI, FAI, MAI, PbI2, and PbBr2 were dissolved in a mixed solution of DMF and DMSO with a volume ratio of 8.5:1.5 in a molar ratio of 0.05:0.81:0.14:0.78:0.22. 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 The volume ratio of 3 moles was 1.4 moles per liter, and the mixture was stirred for 12 hours to obtain a perovskite precursor solution.

[0033] (4) Preparation of spiro-OMeTAD+MWCNT:NiO dispersion:

[0034] First, a certain amount of Ni-modified multi-walled carbon nanotube powder (MWCNT:Ni) (outer diameter: 10-20 nm, length: 10-30 μm, carbon nanotube content: >38 wt%, purchased from Zhongke Times Nano, Chengdu, Sichuan) was placed in a muffle furnace and heated to 200℃ in air for 30 minutes to fully oxidize the Ni in MWCNT:Ni to NiO, thus obtaining NiO-modified multi-walled carbon nanotube powder (MWCNT:NiO). Then, 0.15 mg of MWCNT:NiO powder was dispersed in 10 mL of chlorobenzene, followed by ultrasonic treatment (ultrasonic power 800 W, frequency 40 kHz) for about 1 hour, and then stirred on a magnetic stirring table at 3000 rpm for two hours to obtain a MWCNT:NiO chlorobenzene dispersion.

[0035] The method for preparing spiro-OMeTAD solution is as follows: 72.5 mg of spiro-OMeTAD powder is weighed into a small sample vial, and then 1 mL of chlorobenzene, 18 μL of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and 28.5 μL of 4-tert-butylpyridine are added. The mixture is stirred for 12 h to obtain spiro-OMeTAD solution.

[0036] The preparation method of spiro-OMeTAD+MWCNT:NiO dispersion is similar to that of spiro-OMeTAD solution, except that 1 mL of chlorobenzene is replaced with 1 mL of MWCNT:NiO chlorobenzene dispersion.

[0037] (5) The ITO substrate with an area of ​​2.0cm×2.0cm was ultrasonically cleaned with deionized water, isopropanol and acetone for 45 minutes each. Finally, the ITO substrate was dried with nitrogen and subjected to ultraviolet treatment (wavelength 254 nm, temperature about 50℃) for 15 minutes.

[0038] (6) Take 100 μL of SnO2-KCl solution in air and spin-coat it on ITO glass at 5500 rpm for 9 s. After spin-coating, anneal at 100℃ for 5 minutes and then at 150℃ for 10 minutes. After all annealing is completed, perform UV treatment for 1 hour to obtain ITO / SnO2-KCl sample. The SnO2-KCl film thickness is about 40 nm.

[0039] (7) After the sample is cooled to room temperature, 100 μl of Al2O3 precursor solution is spin-coated onto the ITO / SnO2-KCl sample at 3500 rpm for 20 s. Then, the sample is annealed at 120 °C for 5 minutes and then at 200 °C for 20 minutes to obtain the ITO / SnO2-KCl / Al2O3 sample. The Al2O3 film thickness is about 20 nm.

[0040] (8) ITO / SnO2-KCl / Al2O3 samples were spin-coated with 25 μL (total 25 μL) of Cs at low speed of 1000 rpm and high speed of 4000 rpm under nitrogen protection (this step was carried out in a glove box with water and oxygen content both less than 0.1 ppm, and the water and oxygen content was kept less than 0.1 ppm in all steps using the glove box). 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 )3 Perovskite precursor solution, spin-coated for 4s and 12s respectively, then annealed at 90℃ for 5 minutes on a hot plate, and then annealed at 120℃ for 10 minutes on a hot plate to obtain ITO / SnO2-KCl / Al2O3 / perovskite sample, Cs0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 The thickness of the three layers is approximately 450 nm (because this application spin-coated a relatively uniform mesoporous layer Al2O3 under the perovskite layer, which is beneficial for better perovskite film formation and increased thickness during spin-coating of the perovskite layer. At the same time, the thickness of the spin-coated perovskite layer will also vary slightly due to the influence of the external ambient temperature during the experiment).

[0041] (9) Spin-coat 22 μL of a dispersion of spiro-OMeTAD or spiro-OMeTAD+MWCNT:NiO onto the ITO / SnO2-KCl / Al2O3 / perovskite sample (this step is carried out in a glove box with water and oxygen content of less than 0.1 ppm) at 4500 rpm for 20 s, and then air dry to obtain ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD sample and ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO sample. The thickness of the spiro-OMeTAD film is about 120 nm, and the thickness of the spiro-OMeTAD+MWCNT:NiO film is about 140 nm.

[0042] (10) Finally, the obtained sample was deposited with a gold electrode (80 nm thick) by vacuum evaporation, and the battery assembly was completed. The structure is as follows. Figure 1 As shown.

[0043] Figure 1 The structural diagram of the device is shown.

[0044] Figure 2 The images shown are (a) surface SEM images of spiro-OMeTAD and (b) spiro-OMeTAD+MWCNT:NiO. Figure 2 As can be seen in (a) of the image, there are a large number of pores on the film. Figure 2 As can be seen in (b), the film surface is relatively dense, without pores, and the presence of NiO quantum dot modified multi-walled carbon nanotubes (MWCNT:NiO) can be clearly seen.

[0045] Figure 3 The XRD test results of MWCNT:NiO powder confirm the successful synthesis of the target product MWCNT:NiO.

[0046] Figure 4It is an ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD / Au device and an ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO / Au device. JV Curve results. Table 1 shows the photovoltaic parameters for the two devices. From... Figure 4 As can be seen from the results in Table 1, the overall photovoltaic parameters based on the spiro-OMeTAD+MWCNT:NiO device are significantly improved.

[0047] Table 1. Photovoltaic parameters of two types of solar cells: ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD / Au and ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO / Au. (V) oc Open circuit voltage, J sc (Short-circuit current, FF: fill factor, PCE: photoelectric conversion efficiency)

[0048]

[0049] Figure 5 The ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD / Au devices and the ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO / Au devices were tested in an unpackaged dark state (a) (in air, relative humidity 30%–50%) and under illumination (b) (illuminance is a standard AM1.5 G simulated sunlight, i.e., 100 mW cm⁻¹). -2 Throughout the continuous illumination process, the battery's current-voltage curves were tested at intervals to obtain battery efficiency at different time points, as well as stability tests under three conditions: continuous thermal stability (c) (in a nitrogen glove box with water and oxygen content both less than 0.1 ppm, and the hot stage maintained at 85°C). Figure 5 As can be seen, after 1200 hours in the dark without encapsulation, the ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD / Au device can only maintain a 38% cell efficiency. The ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO / Au device prepared in this application can still maintain a 91% cell efficiency. Figure 5As can be seen from b, after 380 hours of illumination, the ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD / Au device can only maintain 30% battery efficiency, while the ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO / Au device prepared in this application can still maintain 70% battery efficiency. Figure 5 As can be seen from Figure c, after 450 hours at 85℃, the ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD / Au device can only maintain 15% battery efficiency. The ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO / Au device prepared in this application can still maintain 71% battery efficiency. It can be seen from the results in the figure that under these three conditions, the stability of the device based on spiro-OMeTAD+MWCNT:NiO is better than that of the device based on spiro-OMeTAD. Furthermore, the device based on spiro-OMeTAD+MWCNT:NiO prepared in this application has high humidity and high heat resistance.

[0050] Figure 6 The water contact angle tests are for (a) the spiro-OMeTAD thin film and (b) the spiro-OMeTAD+MWCNT:NiO thin film. The water contact angle of the spiro-OMeTAD thin film is 32°, and that of the spiro-OMeTAD+MWCNT:NiO thin film is 73.9°. The results show that the spiro-OMeTAD+MWCNT:NiO film has better hydrophobicity, which further proves that the device based on spiro-OMeTAD+MWCNT:NiO has better stability.

[0051] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions conceived without inventive effort should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for preparing a solar cell by adding MWCNT:NiO in spiro-OMeTAD, characterized by, The method comprises the following steps: (1) clean the ITO substrate, dry and perform ultraviolet treatment; (2) prepare a SnO2-KCl mixed solution in air, then spin-coat the obtained SnO2-KCl mixed solution on the ITO glass, perform annealing treatment after spin-coating, and finally perform ultraviolet treatment to obtain an ITO / SnO2-KCl sample; (3) prepare an Al2O3 precursor solution, then spin-coat the Al2O3 precursor solution on the sample of step (2), perform annealing treatment after spin-coating to obtain an ITO / SnO2-KCl / Al2O3 sample; (4) spin-coat a perovskite precursor solution on the ITO / SnO2-KCl / Al2O3 sample obtained in step (3) under nitrogen protection, and then perform annealing treatment to obtain an ITO / SnO2-KCl / Al2O3 / perovskite sample; (5) spin-coat a spiro-OMeTAD+MWCNT:NiO dispersion liquid on the sample obtained in step (4), and naturally air dry to obtain an ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO sample; the preparation process of the spiro-OMeTAD+MWCNT:NiO dispersion liquid is as follows: MWCNT:NiO is ultrasonically dispersed in chlorobenzene and then magnetically stirred to obtain a 0.01 mg / mL-0.02 mg / mL MWCNT:NiO chlorobenzene dispersion liquid, spiro-OMeTAD powder is added into the MWCNT:NiO chlorobenzene dispersion liquid, and lithium bistrifluoromethanesulfonimide and 4-tert-butylpyridine are added, and stirring is performed for 10-15 hours to obtain the spiro-OMeTAD+MWCNT:NiO dispersion liquid; the preparation process of MWCNT:NiO is as follows: Ni-modified multi-walled carbon nanotube powder is placed in a muffle furnace, heated to 200±10 DEG C in air and kept for 25-35 minutes to obtain NiO-modified multi-walled carbon nanotube powder, which is denoted as MWCNT:NiO; (6) vacuum evaporate a gold electrode on the sample obtained in step (5) to finally obtain a solar cell with a structure of ITO / SnO2-KCl / Al2O3 / perovskite / spiro-OMeTAD+MWCNT:NiO / Au.

2. The method of claim 1, wherein the solar cell is prepared by adding MWCNT:NiO to spiro-OMeTAD. In step (2), the preparation process of the SnO2-KCl mixed solution is as follows: KCl is dissolved in deionized water to prepare a KCl solution with a concentration of 5 mg / ml, and then a SnO2 hydrocolloid solution with a concentration of 15 wt% and the KCl solution with a concentration of 5 mg / ml are mixed according to a volume ratio of 2:1 to prepare the SnO2-KCl mixed solution.

3. The method for preparing a solar cell with MWCNT:NiO added to spiro-OMeTAD according to claim 1, characterized in that, In step (3), the preparation process of the Al2O3 precursor solution is as follows: an isopropyl alcohol solution of Al2O3 with a concentration of 20 wt% and isopropyl alcohol are diluted according to a volume ratio of 1:15 to obtain the Al2O3 precursor solution.

4. The method of claim 1, wherein the solar cell is prepared by adding MWCNT:NiO to spiro-OMeTAD, and In step (4), the perovskite precursor solution is specifically a Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 )3perovskite precursor solution, and the specific preparation process is as follows: CsI, FAI, MAI, PbI2 and PbBr2 are dissolved in a mixed solution of DMF and DMSO with a volume ratio of 8.5:1.5 at a molar ratio of 0.05:0.81:0.14:0.78:0.22, Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.85 Br 0.15 )3molar volume ratio is 1.4 mol / L, and then stirred for 10-15 h to obtain a perovskite precursor solution. ​ 5. The method of claim 1, wherein the solar cell is prepared by adding MWCNT:NiO to spiro-OMeTAD, and In step (5), the concentration of MWCNT:NiO in the MWCNT:NiO chlorobenzene dispersion liquid is 0.015 mg / mL. ​ 6. The method for preparing a solar cell with MWCNT:NiO added to spiro-OMeTAD according to claim 1, characterized in that, In step (2), annealing refers to 100℃ annealing for 5 minutes, and then 150℃ annealing for 10 minutes; in step (3), annealing refers to 120℃ annealing for 5 minutes, and then 200℃ annealing for 20 minutes; in step (4), annealing refers to 90℃ annealing for 5 minutes, and then 120℃ annealing for 10 minutes.

7. The method of claim 1, wherein the solar cell is prepared by adding MWCNT:NiO to spiro-OMeTAD, and In step (5), the ultrasonic power is 800W, the ultrasonic time is 0.5h~1.5h, the rotating speed of magnetic stirring is 3000r / min, and the stirring time is 1.5h~2.5h. ​ 8. The perovskite solar cell with MWCNT:NiO added in spiro-OMeTAD prepared by the preparation method of any one of claims 1 to 7.

9. The perovskite solar cell according to claim 8, characterized in that, The thickness of the SnO2-KCl layer is 40nm, the thickness of the Al2O3 layer is 20nm, the thickness of the perovskite layer is 450nm, the thickness of the spiro-OMeTAD+MWCNT:NiO layer is 140nm, and the thickness of the gold electrode is 80nm.

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