A passivated NiO x Thin film, perovskite solar cells and their fabrication methods

Abstract

This invention belongs to the field of thin film material preparation technology, specifically relating to a passivated NiO x Thin-film perovskite solar cells and their fabrication methods. This invention utilizes SAM formed by mixing DPA-carbazole derivatives and potassium 4-chlorophenyltrifluoroborate as NiO. x The passivation layer of the thin film, potassium 4-chlorophenyltrifluoroborate, is used to fill the vacancies within the SAM structure, ensuring that the SAM completely covers the NiO. x On a thin film. The perovskite solar cell consists of a conductive substrate and a passivated NiO layer, arranged sequentially. x The invention comprises a thin film, a perovskite light-absorbing layer, an electron transport layer, an electron blocking layer, and a metal electrode. The SAM layer is used to enhance the light absorption of NiO. x Interface modification of perovskite solar cells can passivate surface defects in their thin films and reduce non-radiative recombination; it can also improve the interface energy level matching and increase conductivity; thereby improving the open-circuit voltage, fill factor and stability of the device.

Description

A passivated NiO x Thin film, perovskite solar cells and their fabrication methods Technical Field

[0001] This invention belongs to the field of thin film material preparation technology, specifically relating to a passivated NiO x Thin film, perovskite solar cells and their fabrication methods. Background Technology

[0002] In the field of perovskite solar cells, the choice of hole transport layer material is crucial to device performance. Inorganic p-type semiconductor nickel oxide is considered a promising hole transport layer material due to its excellent chemical stability, high optical transmittance, and tunable band structure, especially suitable for inverted perovskite solar cells.

[0003] NiO x Poor interfacial energy level matching between the perovskite layer and the NiO layer leads to significant energy shift and low quasi-Fermi level splitting, which in turn reduces the open-circuit voltage and fill factor. Simultaneously, the perovskite layer and NiO... x The thermal expansion coefficient and lattice mismatch between the elements may cause interfacial strain, exacerbate lattice distortion, and accelerate perovskite degradation; the high oxidation state of Ni limits hole extraction and transport efficiency, reduces electrical conductivity, and leads to charge carrier accumulation at the interface, triggering nonradiative recombination loss.

[0004] Most existing technologies rely on the self-assembly of monolayers to synthesize NiO. x The thin film surface is modified; for example, Reference 1: Z.-E. Shi, T.-H. Cheng, C.-Y. Lung, C.-W. Lin, C.-L. Wang, B.-H. Jiang, Y.-S.Hsiao, C.-P. Chen, Chemical Engineering Journal 2024, 498. Reference 1 modifies NiO by using different SAM self-assembled molecular layers such as Me-4PACz, MeO-2PACz, 2PACz, or 4PADCB. x Thin films; Me-4PACz is (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid, MeO-2PACz is [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, 2PACz is (2-(9H-carbazole-9-yl)ethyl)phosphonic acid, and 4PADCB is 4-(7H-dibenzo[C,G]carbazole-7-yl)butyl]phosphonic acid. Suitable surfaces are formed by self-assembling monolayers and adjusting the energy level arrangement to improve NiO... xThe performance of the base device under single sunlight illumination and indoor lighting conditions was evaluated. Simultaneously, this interface modification altered surface properties, promoted the crystallization of the upper perovskite layer, reduced non-radiative recombination losses, and improved carrier transport.

[0005] However, due to the steric hindrance of the carbazole core, self-assembled single molecules cannot be formed in NiO. x A dense monolayer forms on the surface, leading to NiO x Defects at the interface with the perovskite layer cannot be effectively passivated, resulting in leakage current and non-radiative recombination problems. Summary of the Invention

[0006] To address the steric hindrance of the carbazole core in the aforementioned self-assembled monomolecules, which hinders the formation of a dense monolayer, leading to the perovskite and NiO... x To address the technical problem of ineffective passivation of defects at the bottom of the interface, this invention provides a passivated NiO layer. x Thin film, perovskite solar cells and their fabrication methods.

[0007] The first objective of this invention is to provide a passivated NiO x Thin film, the passivated NiO x Thin films include NiO x Thin film and deposited on NiO x A SAM layer on the thin film; the SAM layer is formed by depositing a mixture of DPA-carbazole derivative and potassium 4-chlorophenyltrifluoroborate in a solvent system; potassium 4-chlorophenyltrifluoroborate is used to fill the vacancies in the SAM structure; the mass ratio of DPA-carbazole derivative to potassium 4-chlorophenyltrifluoroborate is 5:1 to 10; the DPA-carbazole derivative is Me-4PACz, MeO-2PACz or 4PADCB.

[0008] This invention utilizes a SAM layer formed by mixing DPA-carbazole derivatives and potassium 4-chlorophenyltrifluoroborate as NiO. x The passivation layer of the thin film is formed by filling the vacancies in the SAM structure with potassium 4-chlorophenyltrifluoroborate, ensuring that the SAM layer more completely covers NiO. x On the thin film. Simultaneously, the Cl and F atoms in potassium 4-chlorophenyltrifluoroborate effectively passivate NiO. x Surface defects, optimized Ni 3+ / Ni 2+ The ratio of K to F atoms in the SAM layer improves hole extraction capability and bandgap matching. Furthermore, the synergistic effect of K and F atoms in the SAM layer stabilizes the perovskite interface, significantly reduces nonradiative recombination loss, and promotes the formation of high-quality perovskite films. In addition, the SAM layer successfully suppresses Ni... 3+ Redox reactions with perovskite.

[0009] Preferably, the solvent is ethanol.

[0010] Preferably, the thickness of the SAM layer is 20nm to 30nm.

[0011] A second objective of this invention is to provide a perovskite solar cell.

[0012] Preferably, the perovskite solar cell comprises a conductive substrate and passivated NiO. x The thin film, perovskite light-absorbing layer, electron transport layer, electron blocking layer and metal electrode are assembled.

[0013] Preferably, the conductive substrate is ITO, and the performance parameters of the conductive substrate meet the following conditions: sheet resistance ≤ 15 ohms, transmittance ≥ 92%.

[0014] Preferably, the electron transport layer is PC. 61 BM.

[0015] Preferably, the electron blocking layer is a BCP.

[0016] A third objective of this invention is to provide a method for preparing the above-mentioned perovskite solar cell, comprising the following steps:

[0017] Passivated NiO deposited on a conductive substrate x Thin film, in passivated NiO x A perovskite light-absorbing layer is deposited on a thin film, an electron transport layer is deposited on the perovskite light-absorbing layer, an electron blocking layer is deposited on the electron transport layer, and a metal electrode is deposited on the electron blocking layer to obtain a perovskite solar cell.

[0018] Preferably, the perovskite light-absorbing layer is formed by depositing a perovskite precursor solution onto passivated NiO. x Obtained on thin films; the chemical formula of the perovskite precursor is (FA). 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.9 Br 0.1 3.

[0019] Preferably, the perovskite precursor solution is obtained by mixing cesium iodide, methylammonium iodide, lead bromide, formamidinium hydroiodate and lead iodide in a solvent system according to the chemical formula of the perovskite precursor.

[0020] Preferably, the solvent is a mixture of N,N-dimethylformamide and dimethyl sulfoxide, wherein the volume ratio of N,N-dimethylformamide to dimethyl sulfoxide is 4:1.

[0021] Compared with the prior art, the present invention has the following technical effects:

[0022] This invention utilizes SAM formed by mixing DPA-carbazole derivatives and potassium 4-chlorophenyltrifluoroborate as NiO. x The passivation layer of the thin film utilizes potassium 4-chlorophenyltrifluoroborate to fill the vacancies within the SAM structure, ensuring a more complete SAM layer coverage of NiO. x On the thin film; simultaneously, NiO is effectively passivated by Cl and F atoms in potassium 4-chlorophenyltrifluoroborate. x Surface defects, optimized Ni 3+ / Ni 2+ The ratio was improved, enhancing hole extraction capability and bandgap matching. Furthermore, the synergistic effect of K and F atoms in the SAM layer stabilized the perovskite interface, significantly reducing nonradiative recombination loss and promoting the formation of high-quality perovskite films. It also resolved the steric hindrance of the carbazole core in the SAM molecule, which hindered the formation of a dense monolayer, leading to better perovskite and NiO bonding. x The technical problem of the inability to effectively mask defects at the bottom of the interface.

[0023] This invention utilizes a SAM layer to treat NiO x Interface modification of perovskite solar cells passivates surface defects in their thin films and reduces non-radiative recombination; it also improves interface energy level matching and conductivity; thereby enhancing the open-circuit voltage, fill factor, and stability of optoelectronic devices. Attached Figure Description

[0024] Figure 1 shows the NiO in Comparative Example 1. x Scanning electron microscope image of the thin film.

[0025] Figure 2 shows the passivated NiO in Comparative Example 2. x Scanning electron microscope image of the thin film.

[0026] Figure 3 shows the passivated NiO in Example 1. x Scanning electron microscope image of the thin film.

[0027] Figure 4 is a scanning electron microscope image of the perovskite light-absorbing layer in Comparative Example 1.

[0028] Figure 5 is a scanning electron microscope image of the perovskite light-absorbing layer in Comparative Example 2.

[0029] Figure 6 is a scanning electron microscope image of the perovskite light-absorbing layer in Example 1.

[0030] Figure 7 shows the JV curve of the perovskite solar cell prepared in Comparative Example 1.

[0031] Figure 8 shows the JV curve of the perovskite solar cell prepared in Comparative Example 2.

[0032] Figure 9 shows the JV curve of the perovskite solar cell prepared in Example 1.

[0033] Figure 10 shows the JV curve of the perovskite solar cell prepared in Example 2.

[0034] Figure 11 shows the JV curve of the perovskite solar cell prepared in Example 3.

[0035] Figure 12 shows the JV curves of the perovskite solar cells prepared in Examples 1 and 4-6. Detailed Implementation

[0036] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings.

[0037] Unless otherwise specified, all reagents used in this invention are commercially available, and all methods used are conventional techniques in the art.

[0038] It should be noted that the ITO conductive glass used in the following examples has a size of 14.9mm × 14.9mm, a sheet resistance ≤ 15 ohms, a film thickness of 125nm, and a transmittance ≥ 92%. Potassium (4-chlorophenyl)trifluoroborate is abbreviated as PCPTFB.

[0039] Example 1

[0040] A method for fabricating a perovskite solar cell includes the following steps:

[0041] Step 1, Substrate Pretreatment:

[0042] Immerse the ITO conductive glass in water containing detergent for 10 minutes and rub the conductive surface repeatedly 20 times to remove surface dust. Then, ultrasonically clean it for 15 minutes each with deionized water, isopropanol, and anhydrous ethanol. Finally, soak it in anhydrous ethanol for later use.

[0043] The cleaned ITO conductive glass was placed in an ultraviolet ozone cleaner for 10 minutes to remove organic contaminants from the surface, resulting in pretreated ITO conductive glass.

[0044] Step 2: Preparation of passivated NiO x film:

[0045] 20mg NiO x Dissolved in 1 mL of deionized water, sonicated in an ice bath for 10 min, and then filtered through a 0.22mm aqueous filter to obtain NiO. x Solution.

[0046] Using pretreated ITO conductive glass as a substrate, 80 µL of NiO was pipetted in. x The solution was dropped onto the substrate for spin-coating deposition. The spin-coating speed was controlled at 2000 rpm / s, and the spin-coating time was 30 s. After spin-coating, the substrate was placed on a heating stage at 120℃ for annealing for 15 min to obtain NiO. x film.

[0047] Dissolve 0.3 mg of PCPTFB and 0.5 mg of Me-4PACz in 1 mL of anhydrous ethanol and stir at 800 rpm / min for 2 h to obtain SAM solution.

[0048] In a glove box with humidity <0.01ppm, using NiO x Using a thin film as a substrate, 70 µL of SAM solution was pipetted onto NiO. x Spin-coating deposition was performed on the thin film, with the spin-coating speed controlled at 3000 rpm / s and the spin-coating time at 30 s. After spin-coating, the film was annealed on a heating stage at 100℃ for 10 min to obtain passivated NiO. x film.

[0049] Step 3: Prepare the perovskite light-absorbing layer:

[0050] 18.2 mg of cesium iodide, 35.6 mg of methylammonium iodide, 77.05 mg of lead bromide, 190.2 mg of formamidinium hydroiodate and 548.6 mg of lead iodide were dissolved in 800 μL of N,N-dimethylformamide and 200 μL of dimethyl sulfoxide. The solution was stirred at 800 rpm / min for 2 h at room temperature to obtain a perovskite precursor solution.

[0051] In a glove box with humidity <0.01ppm, passivation of NiO x Using a thin film as a substrate, 50 µL of perovskite precursor solution was pipetted onto passivated NiO. x Spin-coating deposition was performed on the thin film. The low speed of the spin coater was 1000 rpm and the spin coating time was 10 s. The high speed of the spin coater was 4000 rpm and the spin coating time was 40 s. 160 μL of chlorobenzene was added dropwise 5 s before the end of the spin coating. After the spin coating was completed, the film was placed on a heating stage at 100 ℃ and annealed for 60 min to obtain a perovskite light-absorbing layer.

[0052] Step 4: Fabrication of the electron transport layer:

[0053] 20 mg of methyl 6,6-phenyl-C61-butyrate was dissolved in 1 mL of chlorobenzene and stirred at 800 rpm / min for 2 h to obtain PC. 61 BM solution.

[0054] Using a perovskite light-absorbing layer as a substrate, 40 µL of PC was aspirated using a pipette. 61 BM solution was dropped onto the perovskite light-absorbing layer for spin-coating deposition. The spin-coating speed was controlled at 3000 rpm / s and the spin-coating time was 30 s. After spin-coating was completed, the layer was placed on a heating stage at 70°C for annealing for 10 min to obtain the electron transport layer.

[0055] Step 5: Prepare the electron blocking layer:

[0056] Dissolve 0.5 mg of BCP in 1 mL of isopropanol and stir at 800 rpm / min for 2 h to obtain a BCP solution.

[0057] Using the electron transport layer as a substrate, 60 µL of BCP solution was pipetted onto the electron transport layer for spin coating deposition. The spin coating speed was controlled at 6000 rpm / s and the spin coating time was 30 s. After spin coating, the layer was placed on a heating stage at 70 °C for annealing for 10 min to obtain the electron blocking layer.

[0058] Step 6: Fabrication of perovskite solar cells:

[0059] A perovskite solar cell was obtained by evaporating an Ag electrode onto an electron blocking layer using a vacuum deposition machine. The Ag electrode was 100 nm thick.

[0060] Example 2

[0061] A method for fabricating a perovskite solar cell includes the following steps:

[0062] The difference between Example 2 and Example 1 is as follows:

[0063] MeO-2PACz was used to replace MeO-4PACz.

[0064] Example 3

[0065] A method for fabricating a perovskite solar cell includes the following steps:

[0066] The difference between Example 3 and Example 1 is as follows:

[0067] Replace MeO-4PACz with 4PADCB.

[0068] Example 4

[0069] A method for fabricating a perovskite solar cell includes the following steps:

[0070] The difference between Example 4 and Example 1 is as follows:

[0071] The mass ratio of PCPTFB to Me-4PACz is 1:5.

[0072] Example 5

[0073] A method for fabricating a perovskite solar cell includes the following steps:

[0074] The difference between Example 5 and Example 1 is as follows:

[0075] The mass ratio of PCPTFB to Me-4PACz is 1:1.

[0076] Example 6

[0077] A method for fabricating a perovskite solar cell includes the following steps:

[0078] The difference between Example 6 and Example 1 is as follows:

[0079] The mass ratio of PCPTFB to Me-4PACz is 2:1.

[0080] Comparative Example 1

[0081] A method for fabricating a perovskite solar cell includes the following steps:

[0082] Step 1, Substrate Pretreatment:

[0083] Immerse the ITO conductive glass in water containing detergent for 10 minutes and rub the conductive surface repeatedly 20 times to remove surface dust. Then, ultrasonically clean it for 15 minutes each with deionized water, isopropanol, and anhydrous ethanol. Finally, soak it in anhydrous ethanol for later use.

[0084] The cleaned ITO conductive glass was placed in an ultraviolet ozone cleaner for 10 minutes to remove organic contaminants from the surface, resulting in pretreated ITO conductive glass.

[0085] Step 2: Preparation of NiO x film:

[0086] 20mg NiO x Dissolved in 1 mL of deionized water, sonicated in an ice bath for 10 min, and then filtered through a 0.22mm aqueous filter to obtain NiO. x Solution.

[0087] Using pretreated ITO conductive glass as a substrate, 80 µL of NiO was pipetted in. x The solution was dropped onto the substrate for spin-coating deposition. The spin-coating speed was controlled at 2000 rpm / s, and the spin-coating time was 30 s. After spin-coating, the substrate was placed on a heating stage at 120℃ for annealing for 15 min to obtain NiO. x film.

[0088] Step 3: Prepare the perovskite light-absorbing layer:

[0089] 18.2 mg of cesium iodide, 35.6 mg of methylammonium iodide, 77.05 mg of lead bromide, 190.2 mg of formamidinium hydroiodate and 548.6 mg of lead iodide were dissolved in 800 μL of N,N-dimethylformamide and 200 μL of dimethyl sulfoxide. The solution was stirred at 800 rpm / min for 2 h at room temperature to obtain a perovskite precursor solution.

[0090] In a glove box with humidity <0.01ppm, using NiO x Using a thin film as a substrate, 50 µL of perovskite precursor solution was pipetted onto NiO. x Spin-coating deposition was performed on the thin film. The low speed of the spin coater was 1000 rpm and the spin coating time was 10 s. The high speed of the spin coater was 4000 rpm and the spin coating time was 40 s. 160 μL of chlorobenzene was added dropwise 5 s before the end of the spin coating. After the spin coating was completed, the film was placed on a heating stage at 100 ℃ and annealed for 60 min to obtain a perovskite light-absorbing layer.

[0091] Step 4: Fabrication of the electron transport layer:

[0092] 20 mg of methyl 6,6-phenyl-C61-butyrate was dissolved in 1 mL of chlorobenzene and stirred at 800 rpm / min for 2 h to obtain PC. 61 BM solution.

[0093] Using a perovskite light-absorbing layer as a substrate, 40 µL of PC was aspirated using a pipette. 61 BM solution was dropped onto the perovskite light-absorbing layer for spin-coating deposition. The spin-coating speed was controlled at 3000 rpm / s and the spin-coating time was 30 s. After spin-coating was completed, the layer was placed on a heating stage at 70°C for annealing for 10 min to obtain the electron transport layer.

[0094] Step 5: Prepare the electron blocking layer:

[0095] Dissolve 0.5 mg of BCP in 1 mL of isopropanol and stir at 800 rpm / min for 2 h to obtain a BCP solution.

[0096] Using the electron transport layer as a substrate, 60 µL of BCP solution was pipetted onto the electron transport layer for spin coating deposition. The spin coating speed was controlled at 6000 rpm / s and the spin coating time was 30 s. After spin coating, the layer was placed on a heating stage at 70 °C for annealing for 10 min to obtain the electron blocking layer.

[0097] Step 6: Fabrication of perovskite solar cells:

[0098] A perovskite solar cell was obtained by evaporating an Ag electrode onto an electron blocking layer using a vacuum deposition machine. The Ag electrode was 100 nm thick.

[0099] The difference between Comparative Example 1 and Example 1 is as follows:

[0100] In NiO x A perovskite light-absorbing layer was directly deposited on the thin film without NiO. x The thin film is passivated with a SAM layer.

[0101] Comparative Example 2

[0102] A method for fabricating a perovskite solar cell includes the following steps:

[0103] Step 1, Substrate Pretreatment:

[0104] Immerse the ITO conductive glass in water containing detergent for 10 minutes and rub the conductive surface repeatedly 20 times to remove surface dust. Then, ultrasonically clean it for 15 minutes each with deionized water, isopropanol, and anhydrous ethanol. Finally, soak it in anhydrous ethanol for later use.

[0105] The cleaned ITO conductive glass was placed in an ultraviolet ozone cleaner for 10 minutes to remove organic contaminants from the surface, resulting in pretreated ITO conductive glass.

[0106] Step 2: Preparation of passivated NiO x film:

[0107] 20mg NiO x Dissolved in 1 mL of deionized water, sonicated in an ice bath for 10 min, and then filtered through a 0.22mm aqueous filter to obtain NiO. x Solution.

[0108] Using pretreated ITO conductive glass as a substrate, 80 µL of NiO was pipetted in. x The solution was dropped onto the substrate for spin-coating deposition. The spin-coating speed was controlled at 2000 rpm / s, and the spin-coating time was 30 s. After spin-coating, the substrate was placed on a heating stage at 120℃ for annealing for 15 min to obtain NiO. x film.

[0109] Step 3: Prepare passivated SAM film:

[0110] Dissolve 0.5 mg of Me-4PACz in 1 mL of anhydrous ethanol and stir at 800 rpm / min for 2 h to obtain a SAM solution.

[0111] In a glove box with humidity <0.01ppm, using NiO xUsing a thin film as a substrate, 70 µL of SAM solution was pipetted onto NiO. x Spin-coating deposition was performed on the thin film, with the spin-coating speed controlled at 3000 rpm / s and the spin-coating time at 30 s. After spin-coating, the film was annealed on a heating stage at 100℃ for 10 min to obtain passivated NiO. x film.

[0112] Step 3: Preparation of perovskite thin films:

[0113] 18.2 mg of cesium iodide, 35.6 mg of methylammonium iodide, 77.05 mg of lead bromide, 190.2 mg of formamidinium hydroiodate and 548.6 mg of lead iodide were dissolved in 800 μL of N,N-dimethylformamide and 200 μL of dimethyl sulfoxide. The solution was stirred at 800 rpm / min for 2 h at room temperature to obtain a perovskite precursor solution.

[0114] In a glove box with humidity <0.01ppm, passivation of NiO x Using a thin film as a substrate, 50 µL of perovskite precursor solution was pipetted onto passivated NiO. x Spin-coating deposition was performed on the thin film. The low speed of the spin coater was 1000 rpm and the spin coating time was 10 s. The high speed of the spin coater was 4000 rpm and the spin coating time was 40 s. 160 μL of chlorobenzene was added dropwise 5 s before the end of the spin coating. After the spin coating was completed, the film was placed on a heating stage at 100 ℃ and annealed for 60 min to obtain a perovskite light-absorbing layer.

[0115] Step 4: Fabrication of the electron transport layer:

[0116] 20 mg of methyl 6,6-phenyl-C61-butyrate was dissolved in 1 mL of chlorobenzene and stirred at 800 rpm / min for 2 h to obtain PC. 61 BM solution.

[0117] Using a perovskite light-absorbing layer as a substrate, 40 µL of PC was aspirated using a pipette. 61 BM solution was dropped onto the perovskite light-absorbing layer for spin-coating deposition. The spin-coating speed was controlled at 3000 rpm / s and the spin-coating time was 30 s. After spin-coating was completed, the layer was placed on a heating stage at 70°C for annealing for 10 min to obtain the electron transport layer.

[0118] Step 5: Prepare the electron blocking layer:

[0119] Dissolve 0.5 mg of BCP in 1 mL of isopropanol and stir at 800 rpm / min for 2 h to obtain a BCP solution.

[0120] Using the electron transport layer as a substrate, 60 µL of BCP solution was pipetted onto the electron transport layer for spin coating deposition. The spin coating speed was controlled at 6000 rpm / s and the spin coating time was 30 s. After spin coating, the layer was placed on a heating stage at 70 °C for annealing for 10 min to obtain the electron blocking layer.

[0121] Step 6: Fabrication of perovskite solar cells:

[0122] A perovskite solar cell was obtained by evaporating an Ag electrode onto an electron blocking layer using a vacuum deposition machine. The Ag electrode was 100 nm thick.

[0123] The difference from Example 1 is as follows:

[0124] Me-4PACz was used as the SAM layer for NiO x The thin film undergoes passivation treatment.

[0125] Experimental testing.

[0126] 1. SEM characterization.

[0127] As shown in Figure 1, NiO is deposited on an ITO conductive glass substrate. x The film has low coverage and exhibits noticeable pores. If in NiO... x When a perovskite light-absorbing layer is deposited directly on a thin film, the ITO thin film will be in direct contact with the perovskite light-absorbing layer, which will seriously affect the extraction of charge carriers.

[0128] As shown in Figure 2, NiO is deposited on an ITO conductive glass substrate. x After thinning, Me-4PACz was used as the SAM layer for NiO. x The thin film is passivated to obtain passivated NiO. x Thin film. Compared to NiO in Comparative Example 1. x Thin film, single Me-4PACz against NiO x Passivated NiO formed after thin film passivation treatment x The film coverage is significantly improved, and there are no obvious pores; however, the passivated NiO... x The surface of the thin film shows severe aggregation, with some obvious protrusions; in passivated NiO x As the perovskite light-absorbing layer continues to be deposited on the thin film, these protrusions will severely affect the coverage of the perovskite light-absorbing layer, thereby seriously affecting the performance of the perovskite solar cell.

[0129] As shown in Figure 3, compared to the passivated NiO in Comparative Example 2 x In Example 1, the thin film, formed by mixing Me-4PACz and potassium 4-chlorophenyltrifluoroborate, is a SAM layer as NiO. xThe passivation layer of the thin film, resulting in passivated NiO x The film coverage is significantly improved, with no obvious pores; and the passivated NiO x The surface has no obvious protrusions. The perovskite light-absorbing layer is uniformly covered on the passivated NiO. x On the thin film, a uniform hole transport layer will effectively transport holes and block electrons.

[0130] As shown in Figures 4-6, in Comparative Example 1, NiO x The perovskite crystals grown on the thin film are relatively small; the passivated NiO in Comparative Example 2 x The perovskite crystals grown on the thin film are smaller in size; while the passivated NiO in Example 1 x The increased size of the perovskite grown on the thin film is due to the passivated NiO in Example 1. x The thin film is smoother and more even, which allows for more ordered growth of the perovskite crystals. Larger perovskite crystals facilitate carrier transport and reduce recombination.

[0131] 2. Electrical performance testing.

[0132] At AM 1.5G and 100mW / cm² from the Elitetech solar simulator 2 The JV curve of the PSC was recorded under solar illumination, and the corresponding scan rate for this curve was 0.02 V / s. -1 .

[0133] As shown in Figures 7-9 and Table 1, compared with the perovskite solar cells prepared in Comparative Examples 1 and 2, the perovskite solar cell prepared in Example 1 showed improvements in both open-circuit voltage and fill factor to varying degrees, thus exhibiting higher photoelectric conversion efficiency. This is because the passivated NiO in Example 1... x The thin film exhibits higher quality and stronger hole extraction capability in passivated NiO. x The perovskite film deposited on top of the thin film has stronger light absorption capacity and can generate more charge carriers, which is beneficial to the increase of photocurrent. When the scanning direction is changed, the perovskite solar cell devices prepared in Comparative Example 1 and Comparative Example 2 show a large difference in JV curves, i.e., hysteresis. This may be because the poor quality of the hole transport layer and the perovskite film hinders the extraction and transport of charge carriers, resulting in more charge accumulation at the interface between the hole transport layer and the perovskite layer. In contrast, the perovskite solar cell device prepared in Example 1 has a smaller hysteresis effect due to the larger crystal size and better crystallinity of the perovskite.

[0134] As shown in Figures 10 and 11 and Table 1, compared with the perovskite solar cells prepared in Comparative Examples 1 and 2, the perovskite solar cells prepared in Examples 2 and 3 have improved open-circuit voltage and fill factor, thus exhibiting higher photoelectric conversion efficiency.

[0135] As shown in Figure 12 and Table 1, compared with the perovskite solar cells prepared in Comparative Examples 1 and 2, the perovskite solar cells prepared in Examples 4 to 6 have improved open-circuit voltage and fill factor, thus exhibiting higher photoelectric conversion efficiency.

[0136] Table 1. Electrical performance data of perovskite solar cells prepared in Examples 1-6 and Comparative Examples 1-2.

[0137]

[0138] In summary, the perovskite solar cell provided by this invention, based on a SAM layer deposited from a mixture of DPA-carbazole derivatives and potassium 4-chlorophenyltrifluoroborate, exhibits low hysteresis and high photoelectric conversion efficiency. The SAM layer reduces the NiO... x The increased surface roughness of the thin film resulted in a denser perovskite film, improved interfacial energy levels, and promoted the formation of high-quality perovskite films. This invention provides a practical approach and method for the commercialization of perovskite solar cells.

[0139] It should be noted that when numerical ranges are involved in this invention, it should be understood that the two endpoints of each numerical range, as well as any value between the two endpoints, can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described in this invention to avoid redundancy. Although preferred embodiments of this invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments, and all such changes and modifications fall within the scope of this invention.

[0140] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. If these modifications and variations fall within the scope of equivalents of this invention, then this invention also intends to include these modifications and variations.

Claims

1. A passivated NiO x The thin film is characterized by, The passivated NiO x Thin films include NiO x Thin film and deposited on NiO x A SAM layer on the thin film; the SAM layer is formed by depositing a mixture of DPA-carbazole derivative and potassium 4-chlorophenyltrifluoroborate in a solvent system; potassium 4-chlorophenyltrifluoroborate is used to fill the vacancies in the SAM structure; the mass ratio of DPA-carbazole derivative to potassium 4-chlorophenyltrifluoroborate is 5:1 to 10; the DPA-carbazole derivative is Me-4PACz, MeO-2PACz or 4PADCB.

2. The passivated NiO according to claim 1 x The thin film is characterized by, The thickness of the SAM layer is 20nm to 30nm.

3. The passivated NiO according to claim 1 x The thin film is characterized by, The solvent is ethanol.

4. A perovskite solar cell, characterized in that, The perovskite solar cell consists of a conductive substrate and passivated NiO. x The material is assembled from a thin film, a perovskite light-absorbing layer, an electron transport layer, an electron blocking layer, and a metal electrode; the passivated NiO is... x The thin film is the passivated NiO as described in any one of claims 1 to 3. x film.

5. The perovskite solar cell according to claim 4, characterized in that, The conductive substrate is ITO, and the performance parameters of the conductive substrate meet the following conditions: sheet resistance ≤ 15 ohms, transmittance ≥ 92%.

6. A method for preparing a perovskite solar cell according to claim 4, characterized in that, Includes the following steps: Passivated NiO deposited on a conductive substrate x Thin film, in passivated NiO x A perovskite light-absorbing layer is deposited on a thin film, an electron transport layer is deposited on the perovskite light-absorbing layer, an electron blocking layer is deposited on the electron transport layer, and a metal electrode is deposited on the electron blocking layer to obtain a perovskite solar cell.

7. The method for preparing a perovskite solar cell according to claim 6, characterized in that, The perovskite light-absorbing layer is formed by depositing a perovskite precursor solution onto passivated NiO. x Obtained on thin films, the perovskite precursor has the chemical formula (FA). 0.83 MA 0.17 ) 0.95 Cs 0.05 Pb(I 0.9 Br 0.1 3.

8. The method for preparing a perovskite solar cell according to claim 7, characterized in that, The perovskite precursor solution is obtained by mixing cesium iodide, methylammonium iodide, lead bromide, formamidinium hydroiodate, and lead iodide in a solvent system according to the chemical formula of the perovskite precursor.

Images