Cellulose derivative doped perovskite active layer, preparation method thereof and perovskite solar cell

Abstract

The invention discloses a cellulose derivative doped perovskite active layer, a preparation method thereof and a perovskite solar cell, and relates to the technical field of solar cells, and the preparation method comprises the steps: dissolving PbI2, PbBr2, CsI, MABr, FAI and MACl in a solvent to obtain a mixed solution; adding HPMCP into the mixed solution to obtain a perovskite precursor solution; and in a protective gas atmosphere, spin-coating the perovskite precursor solution on a substrate, dropwise adding chlorobenzene in the spin-coating process, and heating the substrate after spin-coating to obtain the perovskite active layer. The method has the beneficial effects that the leakage of lead in perovskite is effectively inhibited by utilizing the physical wrapping effect of HPMCP and the strong coordinate bond effect and hydrogen bond effect of perovskite, the quality of a perovskite active layer thin film can be improved, grain boundary defects are effectively passivated, ion migration is inhibited, and good optical performance is achieved; the photoelectric conversion efficiency and the environmental stability of the halogen hybrid perovskite solar cell device are effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of solar cells, and in particular relates to a cellulose derivative-doped perovskite active layer and a preparation method thereof, and a perovskite solar cell. Background Art

[0002] As a representative of the third generation of photovoltaic technology, perovskite solar cells have achieved a breakthrough in photoelectric conversion efficiency from 3.8% to 27% in just ten years, thanks to their advantages such as high light absorption coefficient, adjustable band gap, low-temperature solution processability and low cost. They are regarded as a potential alternative to traditional silicon-based solar cells. Its lightweight and flexible characteristics have broadened its application scenarios, such as building-integrated photovoltaics (BIPV), wearable devices and space energy systems. However, its large-scale commercialization is limited by the environmental stability defects of the material. The lead compound (PbI2) in the perovskite active layer (such as MAPbI3) is easily decomposed under water, oxygen, heat or light, resulting in lead ions (Pb 2+ ) leakage. Studies have shown that in a hot and humid environment (85°C / 85% RH), the lead dissolution of unencapsulated perovskite films exceeds 10 ppm within 100 hours, far exceeding the environmental safety threshold. In addition, mechanical stress (such as bending and impact) will aggravate the cracking of the encapsulation layer and accelerate the process of lead leakage. Insufficient stability not only affects the life of the device, but also becomes the main cause of the spread of lead pollution, seriously threatening the ecological environment and human health.

[0003] Packaging is the core means to block water and oxygen corrosion and inhibit lead leakage. The current mainstream solution adopts a multi-layer composite structure: the inner layer uses hydrophobic polymers (such as polyparaxylene) or inorganic substances (Al2O3, SiO2) to form a physical barrier to slow down the migration of lead ions; the outer layer uses weather-resistant materials (such as fluorinated glass or metal foil) to resist UV aging and mechanical damage. However, traditional packaging performs poorly in long-term wet heat tests - for example, after 1,000 hours of accelerated aging (85°C / 85% RH), the lead leakage rate of epoxy resin packaged components is still 0.3 μg / cm 2· In recent years, the protective effect of lead ions has been declining year by year due to the interface stratification problem. Recent studies have attempted to introduce self-healing coatings (such as dynamic covalent polymers) or nanocomposites (such as graphene-enhanced PDMS), but such technologies face challenges such as high cost, complex processes, or poor compatibility with perovskite layers, making it difficult to balance long-term stability and large-scale production needs. Therefore, the development of new packaging materials with high barrier properties and good environmental friendliness is crucial to inhibit lead leakage and achieve high-efficiency perovskite solar cells. Summary of the invention

[0004] The object of the present invention is to solve at least one of the technical problems existing in the prior art, and to provide a perovskite active layer doped with cellulose derivatives, a preparation method thereof, and a perovskite solar cell.

[0005] The object of the present invention is to provide the application of a cellulose derivative wrapping material with rich hydroxyl groups and carbon-oxygen double bonds in the side chain in a perovskite solar cell, making full use of the physical wrapping effect of HPMCP (hydroxypropyl methylcellulose phthalate), as well as the strong coordination bond effect and hydrogen bond effect with perovskite, to effectively inhibit lead leakage; at the same time, during the grain growth and nucleation process, it can also delay the nucleation and crystallization growth behavior of perovskite, effectively improving the microscopic morphology, making the grains more uniform and the grain boundaries fewer, greatly improving the crystallinity and stability; in addition, HPMCP can fill the grain boundary gaps, effectively passivate the perovskite crystal defects, stabilize the crystal lattice, thereby improving the photoelectric conversion efficiency and environmental stability of the perovskite solar cell.

[0006] The technical solution of the present invention is as follows: The first aspect of the present invention provides a preparation method of a perovskite active layer doped with cellulose derivatives, comprising the following steps: Dissolve PbI2, PbBr2, CsI, MABr, FAI and MACl in a solvent to obtain a mixed solution; add HPMCP to the mixed solution to obtain a perovskite precursor solution; Under the atmosphere of a protective gas, spin-coat the perovskite precursor solution on a substrate, and drop chlorobenzene during the spin-coating process, and heat the substrate after spin-coating to obtain a perovskite active layer.

[0007] The HPMCP dopant material of the present invention is a cellulose derivative with rich hydroxyl groups and carbon-oxygen double bonds in the side chain, making full use of the physical wrapping effect of HPMCP, as well as the strong coordination bond effect and hydrogen bond effect with perovskite, to effectively inhibit lead leakage; at the same time, during the grain growth and nucleation process, it can also delay the nucleation and crystallization growth behavior of perovskite, effectively improving the microscopic morphology, making the grains more uniform and the grain boundaries fewer, greatly improving the crystallinity and stability; in addition, HPMCP can fill the grain boundary gaps, effectively passivate the perovskite crystal defects, stabilize the crystal lattice, thereby improving the photoelectric conversion efficiency and environmental stability of the perovskite solar cell Optionally, the mass ratio of the added PbI2, PbBr2, CsI, MABr, FAI and MACl is 700-740:26-30:19-20:7.5-8.5:230-246:14-16, and the mass ratio of the added HPMCP to the total mass of PbI2, PbBr2, CsI, MABr, FAI and MACl is 0.01-0.05:99.95-99.99; The solvent is a mixed solution of N, N-dimethylformamide and dimethyl sulfoxide, wherein the volume ratio of N, N-dimethylformamide to dimethyl sulfoxide is 3-5:1.

[0008] Optionally, the mass ratio of the addition of PbI2, PbBr2, CsI, MABr, FAI, and MACl is 718.335:28.2:19.5:8:238.2:15.2, and the mass ratio of the addition of HPMCP to the total mass of PbI2, PbBr2, CsI, MABr, FAI, and MACl is 0.05:99.95; The volume ratio of N, N-dimethylformamide to dimethyl sulfoxide is 4:1.

[0009] Optionally, the specific steps of "spin-coating the perovskite precursor solution on a substrate and dropping chlorobenzene during the spin-coating process" include: At 20-25 °C, the perovskite precursor solution is first spin-coated at a speed of 900-1100 rpm for 9-11 s, and then spin-coated at a speed of 4500-5500 rpm for 25-35 s, and 100-200 mL of chlorobenzene is dropped at 18-22 s during the spin-coating.

[0010] Optionally, the temperature for heating the substrate after spin-coating is 100-150 °C, and the heating time is 30-60 min.

[0011] Specifically, the perovskite active layer is Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 perovskite thin film, which is prepared by spin-coating with an anti-solvent method, and the specific steps are as follows: Dissolve 718.335 mg of PbI2, 28.2 mg of PbBr2, 19.5 mg of CsI, 8 mg of MABr, 238.2 mg of FAI (formamidinium hydroiodide), and 15.2 mg of MACl (methylammonium hydrochloride) in 1 mL of a mixed solution of N, N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), wherein the volume ratio of N, N-dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) is 4:1, stir at room temperature for 12-24 h, and then add 0.05 wt% HPMCP solution (dissolved in DMF) to obtain a perovskite precursor solution.

[0012] Under nitrogen protection, at 20 - 25 °C, spin-coat the perovskite precursor solution at 1000 rpm for 10 s + 5000 rpm for 30 s on the hole transport layer. At 20 s, add 200 mL of chlorobenzene dropwise. After spin-coating, place the substrate on a hot stage and heat at 100 - 150 o °C for 30 - 60 min. After cooling, form Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 perovskite thin film, and the thickness of the perovskite active layer is 500 - 700 nm.

[0013] The second aspect of the present invention provides the perovskite active layer obtained by the preparation method described above, and the thickness of the perovskite active layer is 500 - 700 nm.

[0014] The third aspect of the present invention provides a perovskite solar cell including the perovskite active layer.

[0015] Optionally, the perovskite solar cell further includes: A conductive glass substrate; A hole transport layer, which is disposed on the substrate, and the perovskite active layer is disposed on the hole transport layer; A phenethylammonium iodide modification layer, which is disposed on the perovskite active layer; An electron transport layer, which is disposed on the phenethylammonium iodide modification layer; A metal electrode layer, which is disposed on the electron transport layer; Wherein, the thickness of the hole layer is 20 - 40 nm, and the thickness of the metal electrode layer is 100 - 200 nm.

[0016] The third aspect of the present invention provides a preparation method of the perovskite solar cell, including the following steps: S1. Pretreat the substrate; S2. Prepare a [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) hole transport layer on the substrate; S3. Deposit an HPMCP-doped Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 perovskite active layer on the surface of the hole transport layer; S4. Spin-coat a phenethylammonium iodide modification layer on the surface of the perovskite active layer; S5. Spin-coat the electron transport materials 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]-C-61 (PCBM) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) on the surface of the phenethylammonium iodide modification layer to obtain an electron transport layer; S6. Evaporate a metal electrode on the electron transport layer to obtain a perovskite solar cell.

[0017] Optionally, the specific steps of step S1 include: successively ultrasonically clean the laser-etched ITO glass with deionized water, isopropyl alcohol, and ethanol for 20 minutes each, dry it with a hair dryer, and then perform plasma treatment for 5 minutes; The specific steps of step S2 include: dissolve MeO-2PACz powder in ethanol, with a concentration of 0.8~1.2 mg / mL -1 , mix evenly to form a MeO-2PACz solution, spin-coat it on the substrate by spin coating, with a spin coating rate of 3800~4200 rpm and a spin coating time of 25~35 s, and then perform heat treatment at a temperature of 80~120 °C for 8~12 min to prepare a MeO-2PACz hole transport layer; The specific steps of step S4 include: prepare a 0.8~1.2 mg / mL -1 isopropyl alcohol solution of phenethylammonium iodide, spin-coat it on the surface of the perovskite active layer at 3000~6000 rpm for 25~35 s to obtain a phenethylammonium iodide modification layer; The specific steps of step S5 include: dissolve PCBM in chlorobenzene, with a concentration range of 20~25 mg / mL -1 , to obtain a PCBM solution; dissolve BCP in isopropyl alcohol, with a concentration of 0.4~0.6 mg / mL -1 , stir for 5~7 hours to obtain a BCP solution; spin-coat the PCBM solution on the phenethylammonium iodide modification layer at a rotation speed of 1500~3000 rpm, and treat it at 80~100 o °C for 25~35 min to obtain a PCBM layer; then spin-coat the BCP solution on the PCBM layer to obtain an electron transport layer.

[0018] In step S6, the metal electrode is any one of gold, silver, or copper, and is formed into a film by vacuum thermal evaporation, with an evaporation rate of 0.2~1.2 Å / s, and the film thickness of the metal electrode is 100~200 nm.

[0019] The present invention has at least one of the following beneficial effects: The present invention uses an HPMCP (hydroxypropyl methylcellulose phthalate) wrapping material as an additive for the perovskite active layer. It can not only physically wrap the perovskite lattice, fill the lattice gaps, and inhibit the erosion of water and oxygen and lead leakage, but also chemically form a coordination bond with lead ions in the perovskite and have a strong hydrogen bond with FA ions, which can stabilize the lattice and inhibit ion migration. Therefore, the device performance is effectively improved, the photoelectric conversion efficiency is as high as 23.43%, and lead leakage is effectively inhibited. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of a perovskite solar cell.

[0021] Figure 2 It is a transmission electron microscope image (TEM) of perovskite doped with HPMCP material.

[0022] Figure 3 It is a scanning electron microscope image (SEM) of a standard sample and a perovskite thin film doped with HPMCP material.

[0023] Figure 4 It is an X-ray photoelectron spectroscopy (XPS) of a standard sample and a perovskite thin film doped with HPMCP material.

[0024] Figure 5 It is a photoluminescence spectrum of a standard sample and a perovskite thin film doped with HPMCP material.

[0025] Figure 6 It is the lead content when a standard sample and an unencapsulated perovskite device modified with HPMCP are dissolved in water.

[0026] Figure 7 It is the influence of different gradient doping doses of HPMCP on the device efficiency.

[0027] Figure 8 It is the current-voltage curve of a standard sample and a perovskite device modified with HPMCP Figure 9 It is the stability curve of a standard sample and a perovskite device modified with HPMCP. Detailed Embodiments

[0028] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clear, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] Embodiment 1 A preparation method of a perovskite solar cell includes the following steps: S1. The laser-etched ITO glass is ultrasonically cleaned with deionized water, isopropanol, and ethanol for 20 minutes in sequence, dried with a hair dryer, and then plasma-treated for 5 minutes to obtain the conductive substrate ITO. S2. A hole transport layer of [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz) is prepared on the substrate. The specific steps are as follows: Dissolve MeO-2PACz powder in ethanol, with a concentration of 1 mg / mL. -1 After shaking evenly to form a MeO-2PACz solution, spin-coat it on the conductive substrate ITO using the spin-coating method at a spin-coating rate of 4000 rpm for 30 s. Subsequently, heat-treat it at 100 °C for 10 min. The thickness of the formed hole layer is 30 nm.

[0030] S3. Deposit Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 perovskite active layer. The perovskite active layer is modified with a hydroxypropyl methylcellulose phthalate (HPMCP) dopant material. The HPMCP used in this example is purchased from Adamas Company, with a CAS of 9050-31-1. The structural formula of HPMCP is as follows: It can be seen from the above structural formula that the HPMCP polymer has rich functional groups.

[0031] The specific steps of S3 are as follows: S3.1. Dissolve 718.335 mg of PbI2, 28.2 mg of PbBr2, 19.5 mg of CsI, 8 mg of MABr, 238.2 mg of FAI, and 15.2 mg of MACl in 1 mL of a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), where the volume ratio of N,N-dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) is 4:1. Stir at room temperature for 24 h, and then add 0.05 wt% of the HPMCP encapsulant to obtain a perovskite precursor solution.

[0032] S3.2. Under nitrogen protection, at 25 °C, spin-coat the perovskite precursor solution on the hole transport layer at 1000 rpm for 10 s + 5000 rpm for 30 s. Add 200 μL of chlorobenzene at 20 s. After spin-coating, place the substrate on a hot stage and heat at 100 °C for 50 min. After cooling, form Cs 0.05 (FA0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 perovskite thin film, and the thickness of the perovskite active layer is 600 nm.

[0033] S4. Spin-coat a phenethylammonium iodide modification layer on the surface of the perovskite active layer, and the specific steps are as follows: Prepare a 1 mg mL -1 phenethylammonium iodide isopropanol solution, and spin-coat it on the surface of the perovskite thin film at 5000 rpm for 30 s to obtain the modification layer.

[0034] S5. Spin-coat an electron transport material 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]-C-61 (PCBM) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) on the surface of the phenethylammonium iodide modification layer to prepare an electron transport layer, and the specific steps are as follows: Dissolve 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]-C-61 (PCBM) in chlorobenzene, and its concentration range is 20 mg mL -1 , dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in isopropanol, and the concentration is 0.5 mgmL -1 , and stir for 6 hours. Spin-coat the PCBM solution on the phenethylammonium iodide modification layer at a speed of 4000 rpm, and then treat it at 90 o °C for 30 min to obtain the electron transport layer. Then spin-coat the BCP solution on the PCBM electron transport layer without annealing.

[0035] S6. Evaporate a metal electrode on the electron transport layer, and the specific steps are as follows: The metal electrode is silver, and the film is formed by vacuum thermal evaporation. The evaporation rate is 1 Å / s, and the film thickness of the metal electrode is 100 nm, to prepare a Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 perovskite solar cell.

[0036] The structural schematic diagram of the perovskite solar cell prepared in Example 1 is as Figure 1As shown, from bottom to top are the conductive substrate ITO layer, the MeO-2PACz hole transport layer, the cellulose derivative doped perovskite active layer, the phenylethylamine iodide (PEAI) modification layer, the 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]-C-61 (PCBM) electron transport layer, the 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP) modification layer and the Ag metal electrode layer.

[0037] Example 2 The only difference from Example 1 is that the amount of HPMCP added is changed to 0.02 wt %, and the rest is the same as Example 1.

[0038] Example 3 The only difference from Example 1 is that the amount of HPMCP added is changed to 0.04 wt %, and the rest is the same as Example 1.

[0039] Example 4 The only difference from Example 1 is that the amount of HPMCP added is changed to 0.06 wt %, and the rest is the same as Example 1.

[0040] Comparative Example 1 The difference from Example 1 is that the perovskite active layer in step S3 is not modified with hydroxypropyl methylcellulose phthalate (HPMCP) dopant material, and the other steps are the same as Example 1.

[0041] The samples prepared in Examples 1 to 4 and Comparative Example 1 were tested for performance. The test results are as follows: Figures 2 - 9 As shown, Figures 2 - 9 The “hydroxypropyl methylcellulose phthalic acid” in the table refers to the sample prepared in Example 1, and the “standard sample” refers to the sample prepared in Comparative Example 1.

[0042] like Figure 2 Shown is a transmission electron microscopy (TEM) image of the HPMCP-doped perovskite prepared in Example 1. The black color is the perovskite and the gray color is the cellulose derivative, indicating that the perovskite grains are wrapped by the HPMCP.

[0043] like Figure 3 Shown are scanning electron microscope (SEM) images of the standard sample and perovskite film doped with HPMCP material. Compared with the standard sample, the grain size of the perovskite film modified with HPMCP encapsulating agent is more uniform and the grain boundary gaps are filled.

[0044] like Figure 4 The X-ray photoelectron spectroscopy (XPS) of the standard sample and the perovskite film doped with HPMCP material is shown. Compared with the standard sample, the shift of the lead peak of the perovskite film modified with HPMCP wrapper indicates that HPMCP can bind to Pb2+ Interaction

[0045] As Figure 5 shown in the photoluminescence spectra of the standard sample and the perovskite film doped with HPMCP material, the carrier transport performance of the perovskite film modified with HPMCP encapsulant is better than that of the standard sample.

[0046] As Figure 6 shown in the lead content when the standard sample and the unencapsulated perovskite device modified with HPMCP are dissolved in water. Compared with the standard sample, the lead leakage of the perovskite device modified with HPMCP encapsulant is lower after being dissolved in water, proving that HPMCP can effectively inhibit lead leakage.

[0047] As Figure 7 shown in the effect of different gradients of HPMCP doping dosage on the device efficiency. The device efficiency is the highest when the addition amount of HPMCP is 0.05 wt%, proving that the optimal doping amount of the HPMCP dopant is 0.05 wt%.

[0048] As Figure 8 shown in the current-voltage curves of the standard sample and the perovskite device modified with HPMCP. As Figure 9 shown in the stability curve of the standard sample and the perovskite device modified with HPMCP. It can be seen from Figures 8 - 9 that the device performance after HPMCP modification in Example 1 is as follows: under standard simulated sunlight (AM 1.5G, 100mW / cm 2 ²), open circuit voltage = 1.12V; short circuit current = 24.56mA / cm 2 ²; fill factor = 85.17%; photoelectric conversion efficiency = 23.43%. While the device performance of the sample in Comparative Example 1 is: under standard simulated sunlight (AM 1.5G, 100mW / cm 2 ²), open circuit voltage = 22.91V; short circuit current = 1.33mA / cm 2 ²; fill factor = 83.38%; photoelectric conversion efficiency = 21.65%. It can be seen from this that, compared with Comparative Example 1, the device performance prepared in Example 1 is significantly improved.

[0049] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a cellulose derivative-doped perovskite active layer, characterized in that: The following steps are involved: Dissolving PbI2, PbBr2, CsI, MABr, FAI and MACl in a solvent to obtain a mixed solution; adding HPMCP to the mixed solution to obtain a perovskite precursor solution; In a protective gas atmosphere, the perovskite precursor solution is spin-coated on a substrate, and chlorobenzene is added dropwise during the spin-coating process. After the spin-coating, the substrate is heated to obtain a perovskite active layer.

2. The preparation method according to claim 1, characterized in that: The added mass ratio of PbI2, PbBr2, CsI, MABr, FAI and MACl is 700-740: 26-30: 19-20: 7.5-8.5: 230-246: 14-16, and the ratio of the added mass of HPMCP to the total mass of PbI2, PbBr2, CsI, MABr, FAI and MACl is 0.01-0.05: 99.95-99.99; The solvent is a mixed solution of N, N-dimethylformamide and dimethyl sulfoxide, wherein the volume ratio of N, N-dimethylformamide to dimethyl sulfoxide is 3-5:

1.

3. The preparation method according to claim 2, characterized in that: The added mass ratio of PbI2, PbBr2, CsI, MABr, FAI and MACl is 718.335:28.2:19.5:8:238.2:15.2, and the ratio of the added mass of HPMCP to the total mass of PbI2, PbBr2, CsI, MABr, FAI and MACl is 0.05:99.95; The volume ratio of N, N-dimethylformamide to dimethyl sulfoxide is 4:

1.

4. The preparation method according to claim 1, characterized in that: The specific steps of "spin coating the perovskite precursor solution on the substrate and dropwise adding chlorobenzene during the spin coating process" include: At 20-25° C., the perovskite precursor solution was first spin-coated at a rotation speed of 900-1100 rpm for 9-11 s, and then spin-coated at a rotation speed of 4500-5500 rpm for 25-35 s, and 100-200 mL of chlorobenzene was added dropwise at 18-22 s of the spin coating.

5. The preparation method according to claim 1, characterized in that: After spin coating, the substrate is heated at a temperature of 100-150° C. for a heating time of 30-60 minutes.

6. A perovskite active layer obtained by the preparation method according to any one of claims 1 to 5, characterized in that: The thickness of the perovskite active layer is 500-700 nm.

7. A perovskite solar cell, characterized in that: Comprising the perovskite active layer as claimed in claim 6.

8. The perovskite solar cell according to claim 7, characterized in that: Also includes: substrate; A hole transport layer, which is disposed on the substrate, and the perovskite active layer is disposed on the hole transport layer; A phenethylammonium iodide modification layer disposed on the perovskite active layer; An electron transport layer, which is disposed on the phenethylammonium iodide modified layer; A metal electrode layer, which is disposed on the electron transport layer; Wherein, the thickness of the hole layer is 20-40 nm, and the thickness of the metal electrode layer is 100-200 nm.

9. A method for preparing a perovskite solar cell according to any one of claims 7 to 8, characterized in that: The following steps are involved: S1, pre-treating the substrate; S2, preparing a MeO-2PACz hole transport layer on the substrate; S3, depositing HPMCP-doped Cs on the surface of the hole transport layer 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 perovskite active layer; S4, spin coating a phenethylammonium iodide modification layer on the surface of the perovskite active layer; S5, spin coating the electron transport materials PCBM and BCP on the surface of the phenethylammonium iodide modified layer to obtain an electron transport layer; S6. Vapor-depositing a metal electrode on the electron transport layer to obtain a perovskite solar cell.

10. The preparation method according to claim 9, characterized in that: The specific steps of step S2 include: dissolving MeO-2PACz powder in ethanol to a concentration of 0.8-1.2 mg mL -1 , after being uniformly mixed, a MeO-2PACz solution is formed, which is spin-coated on the substrate by a spin coating method, with a spin coating rate of 3800-4200 rpm and a spin coating time of 25-35 s, followed by a heat treatment temperature of 80-120°C for 8-12 min to prepare a MeO-2PACz hole transport layer; The specific steps of step S4 include: preparing 0.8~1.2mg mL -1 A phenethylammonium iodide isopropanol solution is spin-coated on the surface of the perovskite active layer at 3000-6000 rpm for 25-35 seconds to obtain a phenethylammonium iodide modified layer; The specific steps of step S5 include: dissolving PCBM in chlorobenzene to a concentration range of 20-25 mg mL -1 , and obtain PCBM solution; dissolve BCP in isopropanol at a concentration of 0.4-0.6 mg mL -1 , stirring for 5 to 7 hours to obtain a BCP solution; spin coating the PCBM solution on the phenethylammonium iodide modification layer at a speed of 1500 to 3000 rpm, 80 to 100 o C treatment for 25-35 min to obtain a PCBM layer; then, a BCP solution is spin-coated on the PCBM layer to obtain an electron transport layer.

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