Perovskite photovoltaic cell with cu(acac)2 material passivating adjacent interfaces of a photoactive layer and method of manufacture thereof

Abstract

The present application relates to a kind of perovskite photovoltaic cell with Cu (acac) 2 material passivation photoactive layer adjacent interface and preparation method thereof.The perovskite photovoltaic cell, from bottom to top, includes transparent conductive substrate, electron transport layer, perovskite photosensitive active layer, hole transport layer and metal electrode, also includes interface passivation layer, the interface passivation layer is embedded between the hole transport layer and perovskite photosensitive active layer or between the electron transport layer and perovskite photosensitive active layer, the interface passivation layer is Cu (acac) 2 material.The present application uses Cu (acac) 2 material as interface passivation layer, embedded between the hole transport layer and perovskite photosensitive active layer or between the electron transport layer and perovskite photosensitive active layer, so that the perovskite photovoltaic cell prepared has the advantages of higher efficiency, longer life, lower cost and higher stability, conducive to the marketization of perovskite photovoltaic cell.

Description

Technical Field

[0001] This invention belongs to the field of thin film materials and devices, specifically relating to a perovskite photovoltaic cell with Cu(acac)2 material passivating the interface between adjacent photosensitive layers and its preparation method. Background Technology

[0002] Perovskite photovoltaic cells have achieved efficiencies exceeding 25%, demonstrating significant commercial potential. However, stability has consistently hampered their commercialization process, drawing considerable attention from both the research and industry communities. To improve the efficiency and stability of these devices, in addition to fabricating high-quality perovskite photosensitive layers, appropriate interface modification and passivation are crucial.

[0003] Currently, many results on interface modification and passivation of perovskite photosensitive layers have been reported both domestically and internationally (J.Xia et al., Energy Environ. Mater. 2022, 0, 1-24). Inserting polymers into the perovskite photosensitive layer / hole transport layer achieves a relatively ideal passivation effect (P. Qin et al., Adv. Funct. Mater. 2020, 1908408). Utilizing the δ-FAPbI3 phase, which has a wider band gap than the black phase perovskite, effectively suppresses charge recombination at the interface (J. Zhang et al., Adv. Funct. Mater. 2022, 2204642). Selectively fixing iodine or interacting with undercoordinated lead cations by adjusting the molecular conformation of malondiamide (X. Wang., Chem. Eng. J. 2023, 138559). Iminoimide undecanoic acid is used to improve the crystallinity of the photosensitive layer (L. Zhu et al., Adv. Energy Mater. 2021, 2100529). All these methods reduce the density of trapped states at the interface and suppress ion migration. However, these materials used for interface passivation are constrained by factors such as complicated synthesis, high cost, low carrier mobility, acidity, and hydrophilicity, which seriously hinder their adaptation to the large-scale commercial development of perovskite solar cells. Therefore, it is urgent to find ideal interface modification / passivation materials. Summary of the Invention

[0004] This invention addresses the technical problems existing in the prior art by providing a perovskite photovoltaic cell with Cu(acac)2 material passivating the interface between adjacent photosensitive layers and its preparation method. The Cu(acac)2 material used is an ideal interface modification / passivation material, which can effectively reduce the manufacturing cost of the cell while improving the cell performance.

[0005] In a first aspect, the present invention provides a perovskite photovoltaic cell with Cu(acac)2 material passivating the interface between adjacent photosensitive layers, employing the following technical solution:

[0006] A perovskite photovoltaic cell with Cu(acac)2 material passivating the interface between adjacent photosensitive layers, comprising, from bottom to top, a transparent conductive substrate, an electron transport layer, a perovskite photosensitive active layer, a hole transport layer, and a metal electrode, and further comprising an interface passivation layer, wherein the interface passivation layer is embedded between the hole transport layer and the perovskite photosensitive active layer or between the electron transport layer and the perovskite photosensitive active layer, and the interface passivation layer is made of Cu(acac)2 material.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, the transparent conductive substrate is ITO conductive glass, FTO conductive glass, or flexible transparent plastic PET coated with ITO; the electron transport layer is a SnO2 thin film; and the perovskite photosensitive active layer is a CH3NH3PbI3 perovskite photosensitive active layer or a binary mixture (CsI). 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 (Cs=cesium,FA=HC(NH2)2) mixed perovskite photosensitive active layer; the hole transport layer is Spiro-OMeTAD; the metal electrode is a Cu electrode, an Au electrode, or an Ag electrode.

[0009] Furthermore, the SnO2 thin film was prepared by a solution method, and the specific steps are as follows: 0.1M SnCl2·2H2O was dissolved in ethanol, and it was coated onto a conductive substrate by spin coating, and then annealed in air at 180°C for 60 min.

[0010] Furthermore, the perovskite photosensitive active layer is prepared by an anti-solvent method.

[0011] Furthermore, the interface passivation layer is prepared in an inert gas environment using a Cu(acac)2 solution via spin coating or an antisolvent method.

[0012] Furthermore, the Cu(acac)2 concentration in the Cu(acac)2 solution is 1.2-4.0 mg / ml, and the solvent is isopropanol or chlorobenzene; under an inert gas environment, Cu(acac)2 is modified between the hole transport layer and the perovskite photosensitive active layer or between the electron transport layer and the perovskite photosensitive active layer.

[0013] Furthermore, in the spin coating method, the spin coating speed is 800-2000 rpm and the time is 15 seconds.

[0014] Secondly, the present invention provides a method for preparing a perovskite photovoltaic cell with Cu(acac)2 material passivating the interface between adjacent photosensitive layers, using the following technical solution:

[0015] A method for fabricating a perovskite photovoltaic cell with Cu(acac)2 material passivating the interface between adjacent photosensitive layers includes the following steps:

[0016] 1) Clean and dry the transparent conductive substrate;

[0017] 2) An electron transport layer was prepared on a transparent conductive substrate using a solution method and then placed in an ultraviolet ozone cleaner for 15 minutes under atmospheric conditions and room temperature.

[0018] 3) A perovskite photosensitive active layer is prepared on the surface of the electron transport layer under inert gas protection;

[0019] 4) An interface passivation layer is prepared on the surface of the perovskite photosensitive active layer, wherein the interface passivation layer is Cu(acac)2 material;

[0020] 5) A hole transport layer is prepared on the surface of the interface passivation layer by spin coating;

[0021] 6) Metal electrodes are prepared on the surface of the hole transport layer using an evaporation coating method to obtain perovskite photovoltaic cells;

[0022] or

[0023] 1) Clean and dry the transparent conductive substrate;

[0024] 2) An electron transport layer was prepared on a transparent conductive substrate using a solution method, and then placed in an ultraviolet ozone cleaner for 15 minutes under atmospheric conditions and room temperature.

[0025] 3) An interface passivation layer is prepared on the surface of the electron transport layer, wherein the interface passivation layer is Cu(acac)2 material;

[0026] 4) Under inert gas protection, a perovskite photosensitive active layer is prepared on the surface of the interface passivation layer;

[0027] 5) A hole transport layer was prepared on the surface of the perovskite photosensitive active layer by spin coating;

[0028] 6) Metal electrodes are prepared on the surface of the hole transport layer by evaporation coating to obtain perovskite photovoltaic cells.

[0029] Furthermore, the interface passivation layer is prepared by spin coating, and the specific steps are as follows: spin coating Cu(acac)2 solution onto the surface of the perovskite photosensitive active layer or the electron transport layer to obtain the interface passivation layer.

[0030] The beneficial effects of this invention are as follows: This invention uses Cu(acac)2 material as an interface passivation layer, embedded between the hole transport layer and the perovskite photosensitive active layer or between the electron transport layer and the perovskite photosensitive active layer; this modifies the interface, greatly increases the contact area of ​​the interface, which is beneficial to the transport of charge carriers, suppresses the occurrence of nonradiative recombination, and improves the performance of photovoltaic devices, thereby significantly increasing the open-circuit voltage and fill factor of the cell; the preparation process is simple, the performance is significantly improved, and the manufacturing cost is low, which is conducive to the commercialization of perovskite photovoltaic cells. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the perovskite photovoltaic cell in an embodiment of the present invention, in which the interface between the hole transport layer and the photosensitive layer is passivated with Cu(acac)2 material.

[0032] Figure 2 This is a schematic diagram of the perovskite photovoltaic cell in an embodiment of the present invention, in which Cu(acac)2 material is used to passivate the interface between the electron transport layer and the photosensitive layer.

[0033] Figure 3 The JV curves of perovskite photovoltaic cells with the interface between the interface layer and the photosensitive layer passivated by Cu(acac)2 material are obtained in Examples 1-5 of this invention.

[0034] The attached diagram lists the components represented by each number as follows:

[0035] 1. Transparent conductive substrate; 2. Electron transport layer; 3. Perovskite photosensitive active layer; 4. Interface passivation layer; 5. Hole transport layer; 6. Metal electrode. Detailed Implementation

[0036] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0037] Unless otherwise stated, the raw materials used in this invention are conventional materials in this technical field and are all commercially available. Unless otherwise specified, the test methods and detection methods in the following embodiments are conventional methods, and the instruments used in the tests are all commercially available. For example, Spiro-OMeTAD (English name: 2,2',7,7'-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, Chinese name: 2,2',7,7'-tetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene) was purchased from Xi'an Qiyue Biotechnology Co., Ltd.

[0038] Inorganic transition metal materials are complexes of multiple cation valence states, exhibiting characteristics of amphoteric oxides. Intermediate valence metal cations readily "collapse" and disproportionate to generate high-valence and low-valence metal cations (or elemental metals). High-valence cations possess strong oxidizing properties (P. Qin et al., Surf. Interfaces. 2017, 12, 006) and readily react with perovskite photosensitive layers and degradation products (A. Guerrero et al., ACS Nano. 2016, 10, 218-224), forming insulating metal-iodine materials that prevent the smooth migration of holes. To address this issue, many research groups both domestically and internationally have focused on optimizing and controlling device interfaces by considering factors such as device structure, composition, grain boundaries, and interfaces (S. Akin et al., Adv. Energy Mater. 2019, 1903090). Among these methods, doping (H. Zhang et al., Adv. Mater. 2017, 29, 1604984) and organic material interface engineering (A. Agresti et al., Adv. Funct. Mater. 2020, 2003790) are common interface passivation processes.

[0039] Acetylacetone and its metal complexes have attracted much attention from researchers due to their active chemical reactivity, excellent electron transfer, and energy transfer properties. Metal acetylacetone complexes, on the other hand, are chemically very stable and have long been widely used in many chemical fields. For copper, it is usually represented by metal or oxide ions (Cu). + or Cu 2+ Copper ions exist primarily in the form of Cu. In aqueous solution, copper ions mainly exist as Cu. 2+ It exists in the form of Cu; in an acidic environment, Cu + It is easily oxidized to Cu 2+ However, in a deoxygenated water environment, Cu + It can form a Cu ratio with the added reagent. 2+ More stable complexes, thus increasing Cu + The amount is maintained to keep a high concentration of cuprous ions. Cu can be easily reduced under heating conditions using a reducing agent. 2+ Reduced to Cu + The perovskite photosensitive layer contains iodide ions, and degradation will produce lead, iodine and iodides, exhibiting acidity.

[0040] Based on this, the inventors used Cu(acac)₂ to dope or passivate the perovskite photosensitive layer, and through extensive creative experiments and the accumulation of relevant experimental data, they determined the preparation conditions and confirmed that Cu… + I can 0 Restore to I -Under heat annealing or light irradiation, Pb 0 It will be oxidized to Pb 2+ This can effectively eliminate deep-level defects in the photosensitive layer. Cu 2+ -Cu + The ion pairs are not consumed during redox cycles. Simultaneously, the reaction product CuI is a p-type material with very high hole mobility, which is beneficial for improving the hole mobility of the device. Copper ions can create occupancy sites at perovskite B sites, and O ions from the acetylacetonate group can passivate the dangling bonds of perovskite Pb, suppressing nonradiative recombination and improving device efficiency.

[0041] Meanwhile, after Cu(acac)2 material passivates defects at the adjacent interfaces of the perovskite photosensitive layer, it can effectively suppress nonradiative recombination, accelerate the extraction and transport of charge carriers, passivate interface defects, improve the hydrophobicity of the device, and ultimately improve the efficiency of perovskite photovoltaic cells.

[0042] The following are embodiments of the present invention:

[0043] Example 1

[0044] like Figure 1 As shown, the perovskite photovoltaic cell designed in this embodiment comprises, from bottom to top, a transparent conductive substrate (FTO conductive glass), an electron transport layer (SnO2 thin film), a perovskite photosensitive active layer (CH3NH3PbI3 thin film), an interface passivation layer (Cu(acac)2 thin film), a hole transport layer (Spiro-OMeTAD), and a metal electrode (Au electrode). Its fabrication method includes the following steps:

[0045] (1) Treatment of transparent conductive substrate: Clean the FTO (fluorine-doped SnO2) conductive glass sheet. First, soak the conductive glass sheet in a solution containing a cleaning agent (such as Libai liquid detergent) for 30 minutes. Then, wipe it repeatedly and rinse it with clean water. Next, polish it with polishing powder. Then, place it in a container containing deionized water, acetone and alcohol respectively and sonicate for 20 minutes each. Finally, rinse it twice with deionized water, blow it dry with a nitrogen gun and put it in an oven to dry at 80°C.

[0046] (2) SnO2 thin film preparation: SnO2 thin film was prepared on FTO substrate and placed in a UV ozone cleaner. Under atmospheric and room temperature conditions, it was treated with UV ozone for 15 min. The treated SnO2 / FTO substrate was then quickly transferred into a glove box.

[0047] (3) Preparation of perovskite photosensitive active layer:

[0048] a. Preparation of CH3NH3PbI3 precursor solution: 0.2067 g CH3NH3I and 0.6000 g PbI2 (Aldrich) were mixed and dissolved in 1 mL of a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio 4:1), and stirred at 60 °C for 12 h, and then set aside for use.

[0049] b. Preparation of CH3NH3PbI3 thin film: In an inert gas-protected chamber, the prepared perovskite precursor solution was used as an antisolvent to prepare CH3NH3PbI3 thin films on SnO2 / FTO substrates at low speed of 1000 rpm (5 s) and high speed of 5000 rpm (30 s). 20 s before the end of the high-speed spin coating, 180 μL of chlorobenzene was rapidly dropped onto the surface of the CH3NH3PbI3 thin film, followed by annealing at 100 °C for 30 min.

[0050] (4) Preparation of an interface passivation layer on a perovskite photosensitive film:

[0051] a. Solution preparation: Dissolve the pre-prepared Cu(acac)2 in chlorobenzene solvent, and ultrasonically treat it in an ultrasonic cleaner for 1 hour. The solution concentration is 2.5 mg / mL. Set aside for use.

[0052] b. Preparation of the interface passivation layer: In an inert gas protected chamber, the prepared interface passivation solution is spin-coated onto the surface of the perovskite photosensitive layer film at a low speed of 1200 rpm (15 seconds).

[0053] (5) Preparation of Spiro-OMeTAD hole transport layer: 72.3 mg of Spiro-OMeTAD was dissolved in 1 ml of chlorobenzene solution, and 29 μL of TBP and 17.5 μL of Li-TFSI solution (concentration of 520 mg / mL, solvent of acetonitrile solution) were added to it. Spiro-OMeTAD hole transport layer was prepared on the interface passivation layer film by spin coating at 3500 rpm.

[0054] (6) Electrode preparation: An Au electrode with a thickness of about 80 nm was evaporated on the surface of Spiro-OMeTAD to obtain a perovskite photovoltaic cell.

[0055] To evaluate the photovoltaic characteristics of the perovskite photovoltaic cell with Cu(acac)2 thin film as the interface passivation layer, the JV curve of the cell prepared in this example was tested using a Keithley 2400 meter. The results are as follows: Figure 3 As shown. Battery performance test results indicate that its open-circuit voltage is 1.142V and its short-circuit current is 24.31mA / cm. 2The fill factor is 72.7%, and the energy conversion efficiency is 22.02%.

[0056] Example 2

[0057] like Figure 1 As shown, the perovskite photovoltaic cell designed in this embodiment comprises, from bottom to top, a transparent conductive substrate (ITO conductive glass), an electron transport layer (SnO2 thin film), a perovskite photosensitive active layer (CH3NH3PbI3 thin film), an interface passivation layer (Cu(acac)2 thin film), a hole transport layer (Spiro-OMeTAD), and a metal electrode (Au electrode). Its fabrication method includes the following steps:

[0058] (1) Cleaning the ITO conductive glass sheet: Same as in Example 1.

[0059] (2) SnO2 thin film preparation: Same as in Example 1.

[0060] (3) Preparation of perovskite photosensitive active layer: Same as in Example 1.

[0061] (4) Preparation of an interface passivation layer on a perovskite photosensitive film:

[0062] a. Solution preparation: Dissolve the pre-prepared Cu(acac)2 in a certain amount of isopropanol solvent, and ultrasonically treat it in an ultrasonic cleaner for 1 hour. The solution concentration is 1.2 mg / mL. Set aside for use.

[0063] b. Preparation of the interface passivation layer: In an inert gas protected chamber, the prepared interface passivation solution is spin-coated onto the surface of the perovskite photosensitive layer film at a low speed of 1000 rpm (15 s).

[0064] (5) Preparation of hole transport layer Spiro-OMeTAD: Same as in Example 1.

[0065] (6) Electrode preparation: An Au electrode with a thickness of about 80 nm was evaporated on the surface of Spiro-OMeTAD to obtain a perovskite photovoltaic cell.

[0066] To evaluate the photovoltaic characteristics of the perovskite photovoltaic cell with Cu(acac)2 thin film as the interface passivation layer, the JV curve of the cell prepared in this example was tested using a Keithley 2400 meter. The results are as follows: Figure 3 As shown. Battery performance test results indicate: its open-circuit voltage is 1.111V, and the short-circuit current is 20.62mA / cm. 2 The fill factor is 78.0%, and the energy conversion efficiency is 17.81%.

[0067] Example 3

[0068] like Figure 1 As shown, the perovskite photovoltaic cell designed in this embodiment comprises, from bottom to top, a transparent conductive substrate (ITO conductive glass), an electron transport layer (SnO2 thin film), a perovskite photosensitive active layer (CH3NH3PbI3 thin film), an interface passivation layer (Cu(acac)2 thin film), a hole transport layer (Spiro-OMeTAD), and a metal electrode (Cu electrode). Its fabrication method includes the following steps:

[0069] (1) Cleaning flexible transparent PET plastic coated with ITO: Same as in Example 1.

[0070] (2) SnO2 thin film preparation: Same as in Example 1.

[0071] (3) Preparation of perovskite photosensitive active layer: Same as in Example 1.

[0072] (4) Preparation of an interface passivation layer on a perovskite photosensitive film:

[0073] a. Solution preparation: Cu(acac)2, which was previously prepared by ball milling, was dissolved in chlorobenzene solution with a concentration of 2.5 mg / mL. The solution was then ultrasonically treated in an ultrasonic cleaner for 1 hour and set aside for use.

[0074] b. Preparation of the interface passivation layer: In an inert gas protected chamber, the prepared interface passivation solution is spin-coated onto the surface of the perovskite photosensitive layer film at a low speed of 1200 rpm (15 s).

[0075] (5) Preparation of hole transport layer Spiro-OMeTAD: Same as in Example 1.

[0076] (6) Electrode preparation: A Cu electrode with a thickness of about 80 nm was evaporated on the surface of Spiro-OMeTAD to obtain a perovskite photovoltaic cell.

[0077] To evaluate the photovoltaic characteristics of the perovskite photovoltaic cell with Cu(acac)2 thin film as the interface passivation layer, the JV curve of the cell prepared in this example was tested using a Keithley 2400 meter. The results are as follows: Figure 3 As shown. Battery performance test results indicate that its open-circuit voltage is 0.893V and its short-circuit current is 19.96mA / cm. 2 The fill factor is 47.5%, and the energy conversion efficiency is 8.47%.

[0078] Example 4

[0079] like Figure 2As shown, the perovskite photovoltaic cell designed in this embodiment comprises, from bottom to top, a transparent conductive substrate (FTO conductive glass), an electron transport layer (SnO2 thin film), an interface passivation layer (Cu(acac)2 thin film), a perovskite photosensitive active layer (CH3NH3PbI3 thin film), a hole transport layer (Spiro-OMeTAD), and a metal electrode (Au electrode). Its fabrication method includes the following steps:

[0080] (1) Cleaning the FTO conductive glass sheet: Same as in Example 1.

[0081] (2) SnO2 thin film preparation: Same as in Example 1.

[0082] (3) An interface passivation layer is prepared on the surface of SnO2 thin film.

[0083] a. Solution preparation: Cu(acac)2, which was previously prepared by ball milling, was dissolved in chlorobenzene solution with a concentration of 4.0 mg / mL. The solution was then ultrasonically treated in an ultrasonic cleaner for 1 hour and set aside for use.

[0084] b. Preparation of the interface passivation layer: In an inert gas protected chamber, the prepared interface passivation solution is spin-coated onto the surface of the perovskite photosensitive layer film at a low speed of 1500 rpm (15 s).

[0085] (4) Preparation of perovskite photosensitive active layer:

[0086] a. Preparation of CH3NH3PbI3 precursor solution: 0.2067 g CH3NH3I and 0.6000 g PbI2 (Aldrich) were mixed and dissolved in 1 mL of a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio 4:1), and stirred at 60 °C for 12 h, and then set aside for use.

[0087] b. Preparation of CH3NH3PbI3 thin film: In an inert gas-protected chamber, the prepared perovskite precursor solution was used as an antisolvent to prepare CH3NH3PbI3 thin films on an interface passivation layer / SnO2 / FTO substrate at low speed (1000 rpm / min) (5 s) and high speed (5000 rpm / min) (30 s). 20 s before the end of the high-speed operation, 180 μL of chlorobenzene was rapidly dropped onto the surface of the CH3NH3PbI3 thin film, followed by annealing at 100 °C for 30 min.

[0088] (5) Preparation of hole transport layer Spiro-OMeTAD: Same as in Example 1.

[0089] (6) Electrode preparation: Same as in Example 1.

[0090] To evaluate the photovoltaic characteristics of the perovskite photovoltaic cell with Cu(acac)2 thin film as the interface passivation layer, the JV curve of the cell prepared in this example was tested using a Keithley 2400 meter. The results are as follows: Figure 3 As shown. Battery performance test results indicate: its open-circuit voltage is 1.118V; the battery's short-circuit current is 18.53mA / cm. 2 The fill factor is 75.8%, and the energy conversion efficiency is 15.70%.

[0091] Example 5

[0092] like Figure 1 As shown, the perovskite photovoltaic cell designed in this embodiment includes, from bottom to top, a transparent conductive substrate (FTO conductive glass), an electron transport layer (SnO2 thin film), and a perovskite photosensitive active layer (CsI). 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 The fabrication method of the thin film, the interface passivation layer (Cu(acac)2 thin film), the hole transport layer (Spiro-OMeTAD), and the metal electrode (Au electrode) includes the following steps:

[0093] (1) Cleaning the FTO conductive glass sheet: Same as in Example 1.

[0094] (2) SnO2 thin film preparation: Same as in Example 1.

[0095] (3) Preparation of perovskite photosensitive active layer:

[0096] a. Solution preparation: Cu(acac)2, which was previously prepared by ball milling, was dissolved in chlorobenzene solution with a concentration of 2.5 mg / mL. The solution was then ultrasonically treated in an ultrasonic cleaner for 1 hour and set aside for use.

[0097] b.(CsI) 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 Preparation of precursor solution: 0.5407 g of PbI2, 0.0759 g of PbBr2, 0.2254 g of FAI and 0.0179 g of CsI were mixed and dissolved in 1 mL of a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio 4:1), and stirred at 40 °C for 4 h, and then set aside for use.

[0098] c.(CsI) 0.05 (FAPbI3) 0.95 (PbBr2) 0.05Thin film preparation: In an inert gas protected chamber, the prepared perovskite precursor solution was spin-coated onto a SnO2 / FTO substrate at a low speed of 1000 rpm (5s) and a high speed of 5000 rpm (30s) to prepare (CsI). 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 A thin film was formed, and 180 μL of Cu(acac)₂chlorobenzene solution was dropped onto (CsI) 10 seconds before the high-speed end. 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 The film surface was then annealed at 100°C for 60 min, resulting in (CsI) film. 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 The thickness of the thin film is 450 nm.

[0099] (4) Preparation of an interface passivation layer on a perovskite photosensitive film: Same as in Example 1.

[0100] (5) Preparation of hole transport layer Spiro-OMeTAD: Same as in Example 1.

[0101] (6) Electrode preparation: Same as in Example 1.

[0102] To evaluate the photovoltaic characteristics of the perovskite photovoltaic cell with Cu(acac)2 thin film as the interface passivation layer, the JV curve of the cell prepared in this example was tested using a Keithley 2400 meter. The results are as follows: Figure 3 As shown. Battery performance test results indicate: its open-circuit voltage is 1.131V; the battery's short-circuit current is 24.12mA / cm. 2 The fill factor is 79.8%, and the energy conversion efficiency is 21.04%.

[0103] Example 6

[0104] like Figure 1 As shown, the perovskite photovoltaic cell designed in this embodiment includes, from bottom to top, a transparent conductive substrate (FTO conductive glass), an electron transport layer (SnO2 thin film), and a perovskite photosensitive active layer (CsI). 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 The method for preparing the following components includes: a thin film, an interface passivation layer (Cu(acac)2 thin film), a hole transport layer (Spiro-OMeTAD), and a metal electrode (Ag electrode).

[0105] (1) Cleaning the FTO conductive glass sheet: Same as in Example 1.

[0106] (2) SnO2 thin film preparation: Same as in Example 1.

[0107] (3) Preparation of perovskite photosensitive active layer.

[0108] a. Solution preparation: Cu(acac)2, which was previously prepared by ball milling, was dissolved in chlorobenzene solution with a concentration of 2.5 mg / mL. The solution was then ultrasonically treated in an ultrasonic cleaner for 1 hour and set aside for use.

[0109] b.(CsI) 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 Preparation of precursor solution: 0.5407 g of PbI2, 0.0759 g of PbBr2, 0.2254 g of FAI and 0.0179 g of CsI were mixed and dissolved in 1 mL of a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) (volume ratio 4:1), and stirred at 40 °C for 4 h, and then set aside for use.

[0110] c.(CsI) 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 Thin film preparation: In an inert gas protected chamber, the prepared perovskite precursor solution was spin-coated onto a SnO2 / FTO substrate at a low speed of 1000 rpm (5s) and a high speed of 5000 rpm (30s) to prepare (CsI). 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 A thin film was formed, and 180 μL of Cu(acac)₂chlorobenzene solution was dropped onto (CsI) 10 seconds before the high-speed end. 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 The film surface was then annealed at 100°C for 60 min, resulting in (CsI) film. 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 The thickness of the thin film is 450 nm.

[0111] (4) Preparation of an interface passivation layer on a perovskite photosensitive film: Same as in Example 1.

[0112] (5) Preparation of hole transport layer Spiro-OMeTAD: Same as in Example 1.

[0113] (6) Electrode preparation: An Ag electrode with a thickness of about 80 nm was evaporated on the surface of Spiro-OMeTAD to obtain a perovskite photovoltaic cell.

[0114] To evaluate the photovoltaic characteristics of the perovskite photovoltaic cell with Cu(acac)2 thin film as the interface passivation layer, the JV curve of the cell prepared in this example was tested using a Keithley 2400 meter. The results are as follows: Figure 3 As shown. Battery performance test results indicate: its open-circuit voltage is 0.845V; the short-circuit current is 20.95mA / cm²; the fill factor is 47.7%; and the energy conversion efficiency is 8.45%.

[0115] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A perovskite photovoltaic cell passivating the adjacent interface of the photoactive layer with Cu(acac)2 material, comprising in succession from bottom to top a transparent conductive substrate, an electron transport layer, a perovskite photoactive active layer, a hole transport layer and a metal electrode, characterized in that, Further comprising an interface passivation layer embedded between the hole transport layer and the perovskite photoactive layer or between the electron transport layer and the perovskite photoactive layer, the interface passivation layer being a Cu(acac)2 material, the transparent conductive substrate being ITO conductive glass, FTO conductive glass or ITO-coated flexible transparent plastic PET; the electron transport layer being a SnO2 film; the perovskite photoactive layer being a CH3NH3PbI3 perovskite photoactive layer or a binary mixed (CsI) 0.05 (FAPbI3) 0.95 (PbBr2) 0.05 (Cs = cesium, FA = HC(NH2)2) mixed perovskite photoactive layer; the hole transport layer being Spiro-OMeTAD; The metal electrode is a Cu electrode, an Au electrode or an Ag electrode; the SnO2 thin film is prepared by a solution method, and the specific steps are as follows: 0.1 M SnCl2·2H2O is dissolved in ethanol, and is coated on a conductive substrate by a spin coating method, and is annealed in air at 180℃ for 60 min; the perovskite photoactive layer is prepared by an anti-solvent method; the interface passivation layer is prepared by a spin coating method or an anti-solvent method using a Cu(acac)2 solution in an inert gas environment; the concentration of Cu(acac)2 in the Cu(acac)2 solution is 1.2-4.0 mg / ml, and the solvent is isopropanol or chlorobenzene; in an inert gas environment, Cu(acac)2 is modified between the hole transport layer and the perovskite photoactive layer or between the electron transport layer and the perovskite photoactive layer.

2. The perovskite photovoltaic cell passivating the interface of the photoactive layer with Cu(acac)2 material according to claim 1, characterized in that, In the spin coating method, the spin coating speed is 800-2000 rpm, and the time is 15 s.

3. A method for the preparation of a perovskite photovoltaic cell passivating the interface adjacent to the photoactive layer with Cu(acac)2 material as claimed in claim 1 or 2, characterized by, The method comprises the following steps: 1) washing a transparent conductive substrate and drying; 2) preparing an electron transport layer on the transparent conductive substrate by a solution method, and placing it in a UV ozone cleaner, and treating it with UV ozone under an atmospheric atmosphere and at room temperature for 15 min; 3) preparing a perovskite photoactive layer on the surface of the electron transport layer under inert gas protection; 4) preparing an interface passivation layer on the surface of the perovskite photoactive layer, and the interface passivation layer is a Cu(acac)2 material; 5) preparing a hole transport layer on the surface of the interface passivation layer by a spin coating method; 6) preparing a metal electrode on the surface of the hole transport layer by an evaporation plating method to obtain a perovskite photovoltaic cell; or 1) washing a transparent conductive substrate and drying; 2) preparing an electron transport layer on the transparent conductive substrate by a solution method, and placing it in a UV ozone cleaner, and treating it with UV ozone under an atmospheric atmosphere and at room temperature for 15 min; 3) preparing an interface passivation layer on the surface of the electron transport layer, and the interface passivation layer is a Cu(acac)2 material; 4) preparing a perovskite photoactive layer on the surface of the interface passivation layer under inert gas protection; 5) preparing a hole transport layer on the surface of the perovskite photoactive layer by a spin coating method; 6) preparing a metal electrode on the surface of the hole transport layer by an evaporation plating method to obtain a perovskite photovoltaic cell.

4. The production method according to claim 3, characterized by, The interface passivation layer is prepared by a spin coating method, and the specific steps are as follows: a Cu(acac)2 solution is spin coated on the surface of the perovskite photoactive layer or the surface of the electron transport layer to obtain the interface passivation layer.

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