Three-dimensional polymer buried interface modified efficient and stable trans-perovskite solar cell and preparation method and application thereof

Abstract

The invention discloses an efficient and stable trans-perovskite solar cell modified by a three-dimensional polymer buried interface and a preparation method and application thereof, and relates to the technical field of solar photovoltaics. The cell comprises conductive glass, a hole transport layer, a three-dimensional polymer layer, a perovskite thin film, an electron transport layer and an electrode which are sequentially laminated, wherein the three-dimensional polymer layer is poly (p-vinyl benzyl tripropyl ammonium hexafluorophosphate). According to the invention, poly (p-vinyl benzyl tripropyl ammonium hexafluorophosphate) (TAS) is used as an interface passivation material and is introduced into a buried interface of PSCs, and the efficiency and stability of the perovskite cell are improved by regulating and controlling the modification concentration of a three-dimensional polymer, passivating the defects of the buried interface and enhancing carrier transport and separation at the interface.

Description

Technical Field

[0001] The present invention relates to the technical field of solar photovoltaics, and particularly to a highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried interface modification, a preparation method thereof, and an application thereof. Background Art

[0002] With the increasing global energy demand and the gradual depletion of traditional energy resources, energy shortage has become a severe challenge restricting the sustainable development of society. As a green energy source that is inexhaustible and renewable, solar energy has become a key area of research and industrial development in various countries. Perovskite solar cells (PSCs) have become an important development direction in the field of solar cells due to their high power conversion efficiency, low cost, and simple fabrication process. In particular, inverted perovskite solar cells have excellent electron transport properties, which can effectively reduce charge recombination and improve the power conversion efficiency. At the same time, the inverted structure also provides better mechanical stability and long-term performance guarantee, making it suitable for large-scale applications. However, inverted perovskite solar cells still face interface stability problems, especially the interface defects between the hole transport layer and the perovskite layer, which will reduce the efficiency of the battery and affect its long-term stability. Therefore, improving the interface performance of the battery and reducing interface defects are the key to enhancing the performance of perovskite solar cells.

[0003] Currently, introducing salts, small molecules, ionic liquids, etc. into the buried interface has been proven to passivate interface defects and improve the performance of perovskite solar cells to varying degrees. The Liang research group (2023, Small) introduced a phthalazine diiodide (PDI2) buffer layer into the perovskite bottom interface. The PDI2 buffer layer can lubricate the thermal expansion mismatch between the perovskite and the substrate, release lattice strain, and thus form a void-free buried interface. By introducing PDI2, the degradation caused by voids during the growth process and the increase in non-radiative recombination at the bottom interface are effectively suppressed, thereby extending the working life of perovskite solar cells. The Gao research group (2022, Journal of Energy Chemistry) used an ionic liquid called 4-fluorophenylammonium tetrafluoroborate (FBABF4) to optimize the SnO2 / perovskite interface. This method aims to achieve larger grain sizes and reduce defects, thereby improving the performance and stability of PSCs. The Yang research group (2016, Energy&EnvironmentalScience) inserted 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) between the electron transport layer (ETL) and the perovskite material, which reduced the roughness of the ETL and promoted effective electron contact between the perovskite layer and the ETL.

[0004] However, the use of small-molecule salts as interface modifiers in PSCs also faces some challenges. During the spin-coating process, these small molecules tend to aggregate, resulting in non-uniform distribution on the surface of the transmission layer. This non-uniform distribution may have a negative impact on the performance of the device. In addition, small molecules are vulnerable to ion migration phenomena during long-term stability tests, which further exacerbates the problem by damaging the overall stability of perovskite solar cells. At the same time, the structures of salts such as small molecules are relatively simple and lack sufficient defect passivation sites, making it difficult to achieve the cooperative passivation of multiple defects, and the passivation effect is limited. Therefore, we develop a simple preparation technique to avoid the agglomeration and migration of salts such as small molecules and achieve the cooperative passivation of multiple defects at the perovskite interface, with the expectation of obtaining high-efficiency perovskite solar cells. Summary of the Invention

[0005] In view of the deficiencies in the above-mentioned background technology, the present invention provides a highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried interface modification, as well as a preparation method and application thereof. The present invention designs a poly(vinylbenzyltripropylammonium hexafluorophosphate) (TAS) as an interface passivation material and introduces it into the buried interface of PSCs. By regulating the modification concentration of the three-dimensional polymer, the defects at the buried interface are passivated, the carrier transport and separation at the interface are enhanced, and the efficiency and stability of the perovskite solar cell are improved.

[0006] The first object of the present invention is to provide a highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried interface modification, comprising a conductive glass, a hole transport layer, a three-dimensional polymer layer, a perovskite thin film, an electron transport layer, and an electrode stacked in sequence: The three-dimensional polymer layer is poly(vinylbenzyltripropylammonium hexafluorophosphate).

[0007] Preferably, the hole transport layer comprises nickel oxide and [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid; the electron transport layer comprises [6,6]-phenyl C61 butyric acid methyl ester and fullerene.

[0008] Preferably, the perovskite thin film is prepared from a perovskite precursor solution; Among them, the perovskite precursor solution is prepared by dissolving lead iodide, cesium iodide, lead bromide, methylammonium bromide, and formamidinium iodide in a mixed solvent of dimethylformamide and dimethyl sulfoxide and stirring well overnight.

[0009] Preferably, the thickness of the hole transport layer is 40-60 nm; the thickness of the three-dimensional polymer layer is 20-40 nm; the thickness of the perovskite thin film is 700-800 nm; the thickness of the electron transport layer is 40-60 nm.

[0010] Preferably, the poly(vinylbenzyltripropylammonium hexafluorophosphate) is prepared by reacting poly(benzylethyltripropylammonium chloride) with potassium hexafluorophosphate in an aqueous solution.

[0011] The second object of the present invention is to provide a method for preparing a highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried bottom interface modification, comprising the following steps: Perform surface treatment on the conductive glass; Prepare a hole transport layer on the conductive glass; Prepare a three-dimensional polymer layer on the hole transport layer: Dropwise add and spin-coat a dimethylacetamide solution of poly(vinylbenzyltripropylammonium hexafluorophosphate) on the hole transport layer, and anneal at 90-110 °C for 3-8 minutes to obtain the three-dimensional polymer layer; Prepare a perovskite thin film on the three-dimensional polymer layer; Prepare an electron transport layer on the perovskite thin film; Prepare an electrode on the electron transport layer; Wherein, the concentration of the poly(vinylbenzyltripropylammonium hexafluorophosphate) is 0.05-0.15 mg / mL.

[0012] Preferably, preparing a hole transport layer on the conductive glass includes: Dropwise add a nickel oxide solution on the treated conductive glass, perform spin-coating, and heat at 150-180 °C for 8-12 minutes to obtain a nickel oxide thin film. Subsequently, spin-coat an ethanol solution of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid on the nickel oxide thin film, and then anneal at 90-110 °C for 8-12 minutes.

[0013] Preferably, preparing a perovskite thin film on the three-dimensional polymer layer includes: Spin-coat a perovskite precursor solution on the three-dimensional polymer layer, and then anneal at 100-120 °C for 15-30 minutes. Then, spin-coat a mixed solution of isopropanol and dimethyl sulfoxide containing phenethylammonium bromide, and anneal at 100-120 °C for 3-8 minutes; Wherein, during the process of spin-coating the perovskite precursor solution, ethyl acetate is added drop by drop.

[0014] Preferably, preparing an electron transport layer on the perovskite thin film: includes: Spin-coat [6,6]-phenyl-C61-butyric acid methyl ester and fullerene on the perovskite thin film as the electron transport layer, wherein the spin-coating speed is 2000-4000 rpm and the time is 20-40 seconds; After spin-coating, keep warm at 55-65 °C for 3-6 minutes; Preparing an electrode on the electron transport layer includes: Under vacuum conditions, deposit gold and chromium as the electrode by thermal evaporation.

[0015] The third object of the present invention is to provide an application of a highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried interface modification in the field of photovoltaics.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried interface modification, a preparation method and an application. The three-dimensional polymer TAS adopted by the present invention has low diffusivity and excellent thermal stability, can effectively overcome the problems of volatilization and decomposition at high temperatures, and has rich functional groups. Through coordination, hydrogen bonding and electrostatic interactions, various charge defects (deep-level defects, shallow-level defects) can be passivated. By increasing the perovskite grain size and reducing the grain boundary area, the generation of defects is reduced, the quality of the hole transport layer and the perovskite thin film is improved, and thus the optoelectronic performance and durability of the inverted perovskite solar cell are enhanced.

[0017] The preparation method of the buried interface modification material for the inverted perovskite solar cell of the present invention is simple, the raw materials are low in price, easy to obtain, and the experiment has strong repeatability, meeting the requirements of low-temperature preparation of the inverted perovskite solar cell.

[0018] Through applied research, it is found that the efficiency of the perovskite device modified with the TAS three-dimensional polymer can reach 25.41%, and it maintains 90.6% of the initial efficiency after aging in air for 1000 hours, while the efficiency of the perovskite battery prepared by the conventional method is 23.25%, and it only maintains 43.8% of the initial efficiency after aging in air for 1000 hours. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of an inverted perovskite solar cell with a buried interface modification.

[0020] Figure 2 It is the SEM images of the surface of the perovskite thin film before and after TAS modification: (a) and (b); the SEM images of the cross section of the perovskite thin film before and after TAS modification: (c) and (d).

[0021] Figure 3 It is the short-circuit current density-open circuit voltage curve of the perovskite battery before and after TAS buried interface modification.

[0022] Figure 4 It is the environmental stability test of the non-encapsulated device before and after TAS interface modification: the evolution of the normalized PCE of the non-encapsulated device in the atmosphere of 50±5% at room temperature. Detailed Embodiments

[0023] To enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention will be further described below in conjunction with specific embodiments and drawings. However, the specific embodiments cited do not limit the present invention.

[0024] The object of the present invention is to provide a highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried interface modification, a preparation method and an application thereof. The present invention uses poly(vinylbenzyltripropylammonium hexafluorophosphate) (TAS) as an interface passivation material and introduces it into the buried interface of PSCs. By regulating the modification concentration of the three-dimensional polymer, the defects of the buried interface are passivated, the carrier transport and separation at the interface are enhanced, and the efficiency and stability of the perovskite solar cell are improved.

[0025] To achieve the above object, in the first aspect of the present invention, a highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried interface modification is provided. As shown in Figure 1 the figure, it includes a conductive glass, a hole transport layer, a three-dimensional polymer layer, a perovskite thin film, an electron transport layer, and an electrode stacked in sequence: The three-dimensional polymer layer is poly(vinylbenzyltripropylammonium hexafluorophosphate).

[0026] The three-dimensional polymer TAS adopted in the present invention has low diffusivity and excellent thermal stability, can effectively overcome the problems of volatilization and decomposition at high temperatures, and has rich functional groups. Through coordination, hydrogen bonding and electrostatic interactions, various charge defects (deep-level defects, shallow-level defects) can be passivated. By increasing the perovskite grain size and reducing the grain boundary area, the generation of defects is reduced, the quality of the hole transport layer and the perovskite thin film is improved, and thus the optoelectronic performance and durability of the inverted perovskite solar cell are enhanced.

[0027] Among them, the hole transport layer includes nickel oxide and [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid; the electron transport layer includes [6,6]-phenyl C61 butyric acid methyl ester and fullerene.

[0028] The perovskite thin film is prepared from a perovskite precursor solution; among them, the perovskite precursor solution is prepared by dissolving lead iodide, cesium iodide, lead bromide, methylammonium bromide, and formamidinium iodide in a mixed solvent of dimethylformamide and dimethyl sulfoxide and stirring well overnight.

[0029] Specifically, the perovskite precursor solution is prepared by dissolving lead iodide (PbI2, 1.62 mol / L), cesium iodide (CsI, 0.09 mol / L), lead bromide (PbBr2, 0.11 mol / L), methylammonium bromide (MABr, 0.03 mol / L), and formamidinium iodide (FAI, 1.61 mol / L) in an anhydrous solvent of dimethylformamide (DMF) / dimethyl sulfoxide (DMSO) (volume ratio 5:1), and stirring well overnight. The chemical composition of this precursor solution is (FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 )3, with a total concentration of 1.73 mol / L, forming a CsFAMA triple-cation perovskite precursor solution.

[0030] Among them, the thickness of the hole transport layer is 40 - 60 nm; the thickness of the three-dimensional polymer layer is 20 - 40 nm; the thickness of the perovskite thin film is 700 - 800 nm; the thickness of the electron transport layer is 40 - 60 nm.

[0031] Preferably, the thickness of the hole transport layer is 50 nm; the thickness of the three-dimensional polymer layer is 30 nm; the thickness of the perovskite thin film is 780 nm; the thickness of the electron transport layer is 50 nm.

[0032] The poly(vinylbenzyltripropylammonium hexafluorophosphate) is prepared by reacting poly(benzylethyltripropylammonium chloride) with potassium hexafluorophosphate through an aqueous solution reaction.

[0033] Exemplarily, the synthesis method of poly(vinylbenzyltripropylammonium hexafluorophosphate) includes: First, dissolve benzylethyltripropylammonium chloride ([BTNA]Cl) (3 g) and azobisisobutyronitrile (AIBN) (0.08 g) in 30 mL of ethanol, and react at 80 °C, 150 rpm, and under a nitrogen gas stream. After reacting for 12 hours, add acetone to generate poly(benzylethyltripropylammonium chloride) (P[BTNA]Cl). The precipitate is washed with acetone multiple times to remove the residual [BTNA]Cl. Then, dissolve the obtained P[BTNA]Cl in water and mix it with a 10% (by volume) aqueous solution of potassium hexafluorophosphate (KPF6) (20 mL) to form a precipitate. The precipitate is filtered, washed several times with water, and then detected with an aqueous silver nitrate solution to determine whether the chloride ions are completely removed after washing. Finally, dehydrate the precipitate in a vacuum at 80 °C to obtain poly(vinylbenzyltripropylammonium hexafluorophosphate), abbreviated as P[BTNA][PF6].

[0034] The second aspect of the present invention provides a method for preparing a highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried bottom interface modification, comprising the following steps: Perform surface treatment on the conductive glass; Fabricate a hole transport layer on the conductive glass; Fabricate a three-dimensional polymer layer on the hole transport layer: Drop and spin-coat a dimethylacetamide solution of poly(4-vinylbenzyltripropylammonium hexafluorophosphate) on the hole transport layer, and anneal at 90-110 °C for 3-8 minutes to obtain the three-dimensional polymer layer; Fabricate a perovskite thin film on the three-dimensional polymer layer; Fabricate an electron transport layer on the perovskite thin film; Fabricate an electrode on the electron transport layer.

[0035] Wherein, the concentration of the poly(4-vinylbenzyltripropylammonium hexafluorophosphate) is 0.05-0.15 mg / mL.

[0036] Fabricating a hole transport layer on the conductive glass includes: Drop an aqueous nickel oxide solution on the treated conductive glass, perform spin-coating, and heat at 150-180 °C for 8-12 minutes to obtain a nickel oxide thin film. Subsequently, spin-coat an ethanol solution of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid on the nickel oxide thin film, and then anneal at 90-110 °C for 8-12 minutes.

[0037] Fabricating a perovskite thin film on the three-dimensional polymer layer includes: Spin-coat a perovskite precursor solution on the three-dimensional polymer layer, then anneal at 100-120 °C for 15-30 minutes. Then, spin-coat a mixed solution of isopropanol and dimethyl sulfoxide containing phenethylammonium bromide, and anneal at 100-120 °C for 3-8 minutes; Wherein, during the process of spin-coating the perovskite precursor solution, ethyl acetate is added drop by drop.

[0038] Fabricating an electron transport layer on the perovskite thin film: Include: Spin-coat [6,6]-phenyl-C61-butyric acid methyl ester and fullerene on the perovskite thin film as the electron transport layer, wherein the spin-coating speed is 2000-4000 rpm and the time is 20-40 seconds; After spin-coating, keep the temperature at 55-65 °C for 3-6 minutes.

[0039] Fabricating an electrode on the electron transport layer includes: Under vacuum conditions, deposit gold and chromium as the electrode by thermal evaporation.

[0040] Exemplarily, a method for preparing a highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried bottom interface modification includes: Put indium tin oxide (ITO) glass into an ultrasonic cleaning tank and clean it successively with a detergent-deionized water solution, acetone, and ethanol for 15 minutes. After drying with nitrogen, treat it with ultraviolet ozone for 15 minutes. Subsequently, drop a nickel oxide (NiO x ) solution with a concentration of 20 mg / mL on the ITO and spin-coat it at 3000 rpm for 30 seconds, then heat it at 160 °C for 10 minutes.

[0041] Transfer the treated ITO to a glove box. On the NiO x film, spin-coat [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid (MeO-4PACz, 1.5 mg / mL) dissolved in ethanol at 4000 rpm for 30 seconds, and then anneal it at 100 °C for 10 minutes.

[0042] Subsequently, drop 50 μL of a solution of three-dimensional polymer poly(vinylbenzyltripropylammonium hexafluorophosphate) (TAS, 0.05 - 0.15 mg / mL) in dimethylacetamide (DMF) on the MeO-4PACz film at 4000 rpm and anneal it at 100 °C for 5 minutes.

[0043] Next, mix lead iodide (PbI2, 1.62 mol / L), cesium iodide (CsI, 0.09 mol / L), lead bromide (PbBr2, 0.11 mol / L), methylammonium bromide (MABr, 0.03 mol / L), and formamidinium iodide (FAI, 1.61 mol / L) in a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) with a volume ratio of 5:1, and stir overnight to prepare a CsFAMA triple-cation perovskite precursor solution [(FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 )3, 1.73 mol / L]. Spin-coat the perovskite precursor solution on the three-dimensional polymer layer at 2000 rpm for 10 seconds, and then at 5000 rpm for 40 seconds. Before the operation of spin-coating at 5000 rpm for 40 seconds is completed, dropwise add 200 μL of the antisolvent ethyl acetate (EA) for 15 seconds.

[0044] Transfer the ITO glass to a heating platform and anneal it at 110 °C for 20 minutes. Next, spin-coat a solution of phenethylammonium bromide (PEABr) with a concentration of 2 mg / mL in isopropyl alcohol (IPA) and dimethyl sulfoxide (DMSO) solution (volume ratio 200:1) on the top at 4000 rpm for 30 seconds, and then anneal it at 110 °C for 5 minutes.

[0045] Subsequently, methyl [6,6]-phenyl C61 butyrate (PCBM, purity 99%) and fullerene (C60, purity 99.5%) were spin-coated on the perovskite film as the electron transport layer (ETL) at a mass ratio of 4:1. The spin-coating speed was 3000 rpm, the time was 30 seconds, the temperature was 60 °C, and the time was 5 minutes.

[0046] Finally, under a vacuum condition of 2×10 −6 mbar (effective area 0.1 cm 2 ), 100 nm of gold (Au) and 5 nm of chromium (Cr) were deposited by thermal evaporation to fabricate the device.

[0047] Components of the perovskite solution: FAI, CsI, MABr, PbBr2, PbI2.

[0048] It should be noted that the experimental methods used in the present invention are all conventional methods without special instructions; the reagents and materials used can be purchased on the market without special instructions.

[0049] Example 1 Synthesis of three-dimensional polymer: First, benzylethyltripropylammonium chloride ([BTNA]Cl) (3 g) and azobisisobutyronitrile (AIBN) (0.08 g) were dissolved in 30 mL of ethanol and reacted at 80 °C, 150 rpm, and under a nitrogen gas stream. After reacting for 12 hours, acetone was added to form polybenzylethyltripropylammonium chloride (P[BTNA]Cl). The precipitate was washed several times with acetone to remove the residual [BTNA]Cl. Then, the obtained P[BTNA]Cl was dissolved in water and mixed with a 10% (by volume) aqueous solution of potassium hexafluorophosphate (KPF6) (20 mL) to form a precipitate. The precipitate was filtered, washed several times with water, and then detected with an aqueous silver nitrate solution to determine whether the chloride ions were completely removed after washing. Finally, the precipitate was dehydrated in vacuo at 80 °C to obtain P[BTNA][PF6].

[0050] Preparation of perovskite solar cell: The indium tin oxide (ITO) glass was placed in an ultrasonic cleaning tank and washed successively with a detergent-deionized water solution, acetone, and ethanol for 15 minutes. After drying with nitrogen, it was treated with ultraviolet ozone for 15 minutes.

[0051] Subsequently, a solution of nickel oxide (NiO x ) with a concentration of 20 mg / mL was dropped onto the ITO and spin-coated at 3000 rpm for 30 seconds, and then heated at 160 °C for 10 minutes. The treated ITO was transferred to a glove box, and in NiO xOn the thin film, [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid (MeO-4PACz, 1.5 mg / mL) dissolved in ethanol was spin-coated at 4000 rpm for 30 seconds and then annealed at 100 °C for 10 minutes to obtain the MeO-4PACz thin film; Subsequently, 50 μL of a dimethylacetamide (DMF) solution of three-dimensional polymer poly(vinylbenzyltripropylammonium hexafluorophosphate) (TAS, 0.05 mg / mL) was dropped onto the MeO-4PACz thin film at 4000 rpm and annealed at 100 °C for 5 minutes to obtain the three-dimensional polymer layer; Next, lead iodide (PbI2, 1.62 mol / L), cesium iodide (CsI, 0.09 mol / L), lead bromide (PbBr2, 0.11 mol / L), methylammonium bromide (MABr, 0.03 mol / L) and formamidinium iodide (FAI, 1.61 mol / L) were mixed in dimethylformamide (DMF) / dimethyl sulfoxide (DMSO) (volume ratio 5:1) [(FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 )3, 1.73 mol / L], stirred overnight to prepare a CsFAMA triple-cation perovskite precursor solution. The perovskite precursor solution was spin-coated on the three-dimensional polymer layer at 2000 rpm for 10 seconds and then at 5000 rpm for 40 seconds. Before the operation of spin-coating at 5000 rpm for 40 seconds was completed, 200 μL of antisolvent ethyl acetate (EA) was added dropwise for 15 seconds.

[0052] The ITO glass was transferred to a heating platform and annealed at 110 °C for 20 minutes. Next, phenethylammonium bromide (PEABr) with a concentration of 2 mg / mL was spin-coated on the top in an isopropanol (IPA) and dimethyl sulfoxide (DMSO) solution (volume ratio 200:1) at 4000 rpm for 30 seconds and annealed at 110 °C for 5 minutes to obtain the perovskite thin film; Subsequently, [6,6]-phenyl C61 butyric acid methyl ester (PCBM, purity 99%) and fullerene (C60, purity 99.5%) were spin-coated on the perovskite thin film as an electron transport layer (ETL) at a spin-coating speed of 3000 rpm for 30 seconds and a temperature of 60 °C for 5 minutes.

[0053] Finally, under a vacuum condition of 2×10 −6 mbar (the effective area is 0.1 cm 2), A device was prepared by depositing 100 nm of gold (Au) and 5 nm of chromium (Cr) using the thermal evaporation method. The present invention includes a schematic diagram of the buried bottom interface inverted perovskite solar cell structure, as Figure 1 shown, Test results: The photoelectric conversion efficiency of the inverted perovskite cell is 24.61%.

[0054] Example 2 Synthesis of three-dimensional polymer: First, benzylethyltripropylammonium chloride ([BTNA]Cl) (3 g) and azobisisobutyronitrile (AIBN) (0.08 g) were dissolved in 30 mL of ethanol and reacted at 80 °C, 150 rpm, and a nitrogen gas stream. After reacting for 12 hours, acetone was added to form poly(benzylethyltripropylammonium chloride) (P[BTNA]Cl). The precipitate was washed several times with acetone to remove the residual [BTNA]Cl. Then, the obtained P[BTNA]Cl was dissolved in water and mixed with an aqueous solution of potassium hexafluorophosphate (KPF6) (20 mL) with a volume ratio of 10% to form a precipitate. The precipitate was filtered, washed several times with water, and then detected with an aqueous silver nitrate solution to determine whether the chloride ions were completely removed after washing. Finally, the precipitate was dehydrated in vacuo at 80 °C to obtain P[BTNA][PF6].

[0055] Preparation of perovskite cell: Indium tin oxide (ITO) glass was placed in an ultrasonic cleaning tank and washed successively with a detergent-deionized water solution, acetone, and ethanol for 15 minutes. After drying with nitrogen, it was further treated with ultraviolet ozone for 15 minutes.

[0056] Subsequently, a solution of nickel oxide (NiO x ) with a concentration of 20 mg / mL was dropped onto ITO and spin-coated at 3000 rpm for 30 seconds and heated at 160 °C for 10 minutes. The treated ITO was transferred to a glove box, and on the NiO x film, [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid (MeO-4PACz, 1.5 mg / mL) dissolved in ethanol was spin-coated at 4000 rpm for 30 seconds and then annealed at 100 °C for 10 minutes.

[0057] Subsequently, 50 μL of a solution of the three-dimensional polymer poly(vinylbenzyltripropylammonium hexafluorophosphate) (TAS, 0.10 mg / mL) in dimethylacetamide (DMF) was dropped onto the MeO-4PACz film at 4000 rpm and annealed at 100 °C for 5 minutes.

[0058] Next, lead iodide (PbI2, 1.62 mol / L), cesium iodide (CsI, 0.09 mol / L), lead bromide (PbBr2, 0.11 mol / L), methylammonium bromide (MABr, 0.03 mol / L), and formamidinium iodide (FAI, 1.61 mol / L) were mixed in dimethylformamide (DMF) / dimethyl sulfoxide (DMSO) (volume ratio 5:1) [(FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 )3, 1.73 mol / L], and stirred overnight to prepare a CsFAMA triple-cation perovskite precursor solution. The perovskite precursor solution was spin-coated on the three-dimensional polymer layer at a speed of 2000 rpm for 10 seconds and then at a speed of 5000 rpm for 40 seconds. Before the operation of spin-coating at a speed of 5000 rpm for 40 seconds was completed, 200 μL of the antisolvent ethyl acetate (EA) was added dropwise for 15 seconds.

[0059] The ITO glass was transferred to a heating platform and annealed at 110 °C for 20 minutes. Next, phenethylammonium bromide (PEABr) with a concentration of 2 mg / mL was spin-coated on the top in an isopropanol (IPA) / dimethyl sulfoxide (DMSO) solution (volume ratio 200:1) at a speed of 4000 rpm for 30 seconds and annealed at 110 °C for 5 minutes.

[0060] Subsequently, [6,6]-phenyl C61 butyric acid methyl ester (PCBM, purity 99%) and fullerene (C60, purity 99.5%) were spin-coated on the perovskite film as an electron transport layer (ETL) at a mass ratio of 4:1. The spin-coating speed was 3000 rpm, the time was 30 seconds, the temperature was 60 °C, and the time was 5 minutes.

[0061] Finally, under a vacuum condition of 2×10 −6 mbar (effective area of 0.1 cm 2 ), 100 nm of gold (Au) and 5 nm of chromium (Cr) were deposited by thermal evaporation to prepare the device.

[0062] Test results: The photoelectric conversion efficiency of the inverted perovskite solar cell was 25.41%.

[0063] Example 3 Synthesis of three-dimensional polymer: First, benzylethyltripropylammonium chloride ([BTNA]Cl) (3 g) and azobisisobutyronitrile (AIBN) (0.08 g) were dissolved in 30 mL of ethanol and reacted at 80 °C, 150 rpm, and under a nitrogen gas stream. After reacting for 12 hours, acetone was added to form poly(benzylethyltripropylammonium chloride) (P[BTNA]Cl). The precipitate was washed several times with acetone to remove the residual [BTNA]Cl. Then, the obtained P[BTNA]Cl was dissolved in water and mixed with an aqueous solution of potassium hexafluorophosphate (KPF6) (20 mL) with a volume ratio of 10% to form a precipitate. The precipitate was filtered, washed several times with water, and then detected with an aqueous silver nitrate solution to determine whether chloride ions were completely removed after washing. Finally, the precipitate was dehydrated in vacuo at 80 °C to obtain P[BTNA][PF6].

[0064] Preparation of perovskite solar cells: Indium tin oxide (ITO) glass was placed in an ultrasonic cleaning tank and washed successively with a detergent-deionized water solution, acetone, and ethanol for 15 minutes. After drying with nitrogen, it was further treated with ultraviolet ozone for 15 minutes.

[0065] Subsequently, a solution of nickel oxide (NiO x ) with a concentration of 20 mg / mL was dropped onto the ITO and spin-coated at 3000 rpm for 30 seconds, and then heated at 160 °C for 10 minutes. The treated ITO was transferred to a glove box. On the NiO x film, [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid (MeO-4PACz, 1.5 mg / mL) dissolved in ethanol was spin-coated at 4000 rpm for 30 seconds, and then annealed at 100 °C for 10 minutes.

[0066] Subsequently, 50 μL of a solution of the three-dimensional polymer poly(vinylbenzyltripropylammonium hexafluorophosphate) (TAS, 0.15 mg / mL) in dimethylacetamide (DMF) was dropped onto the MeO-4PACz film at 4000 rpm and annealed at 100 °C for 5 minutes.

[0067] Next, lead iodide (PbI2, 1.62 mol / L), cesium iodide (CsI, 0.09 mol / L), lead bromide (PbBr2, 0.11 mol / L), methylammonium bromide (MABr, 0.03 mol / L), and formamidinium iodide (FAI, 1.61 mol / L) were mixed in dimethylformamide (DMF) / dimethyl sulfoxide (DMSO) (volume ratio 5:1) [(FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I0.95 Br 0.05 )3, 1.73 mol / L], stir overnight to prepare the CsFAMA triple-cation perovskite precursor solution. The perovskite precursor solution is spin-coated at 2000 rpm for 10 seconds and then at 5000 rpm for 40 seconds on the three-dimensional polymer layer. Before the operation of spin-coating at 5000 rpm for 40 seconds is completed, 200 μL of the antisolvent ethyl acetate (EA) is added dropwise for 15 seconds.

[0068] Transfer the ITO glass to a heating platform and anneal it at 110 °C for 20 minutes. Next, spin-coat a solution of phenethylammonium bromide (PEABr) with a concentration of 2 mg / mL in isopropanol (IPA) and dimethyl sulfoxide (DMSO) solution (volume ratio 200:1) on top at 4000 rpm for 30 seconds and then anneal it at 110 °C for 5 minutes.

[0069] Subsequently, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM, purity 99%) and fullerene (C60, purity 99.5%) are spin-coated on the perovskite film as the electron transport layer (ETL) at a mass ratio of 4:1, with a spin-coating speed of 3000 rpm for 30 seconds and a temperature of 60 °C for 5 minutes.

[0070] Finally, under a vacuum condition of 2×10 −6 mbar (effective area is 0.1 cm 2 ), deposit 100 nm of gold (Au) and 5 nm of chromium (Cr) by thermal evaporation to fabricate the device.

[0071] Test results: The photoelectric conversion efficiency of the inverted perovskite solar cell is 24.22%.

[0072] Comparative Example 1 Compared with the example, in the comparative example, the hole transport layer is spin-coated by the "no TAS method"; The specific operation is as follows, Preparation of perovskite solar cell: Put the indium tin oxide (ITO) glass into an ultrasonic cleaning tank and clean it successively with a detergent-deionized water solution, acetone, and ethanol for 15 minutes. After drying with nitrogen, treat it with ultraviolet ozone for 15 minutes.

[0073] Subsequently, a solution of nickel oxide (NiO x ) with a concentration of 20 mg / mL is dropped on the ITO and spin-coated at 3000 rpm for 30 seconds, and then heated at 160 °C for 10 minutes. Transfer the treated ITO to a glove box, and in NiO xOn the thin film, [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid (MeO-4PACz, 1.5 mg / mL) dissolved in ethanol was spin-coated at 4000 rpm for 30 seconds and then annealed at 100 °C for 10 minutes.

[0074] Next, lead iodide (PbI2, 1.62 mol / L), cesium iodide (CsI, 0.09 mol / L), lead bromide (PbBr2, 0.11 mol / L), methylammonium bromide (MABr, 0.03 mol / L), and formamidinium iodide (FAI, 1.61 mol / L) were mixed in dimethylformamide (DMF) / dimethyl sulfoxide (DMSO) (volume ratio 5:1) [(FA 0.98 MA 0.02 ) 0.95 Cs 0.05 Pb(I 0.95 Br 0.05 )3, 1.73 mol / L], stirred overnight to prepare a CsFAMA triple-cation perovskite precursor solution. The perovskite precursor solution was spin-coated on the MeO-4PACz thin film at 2000 rpm for 10 seconds and then at 5000 rpm for 40 seconds. Before the operation was completed, 200 μL of the antisolvent ethyl acetate (EA) was added dropwise for 15 seconds. The ITO glass was transferred to a heating platform and annealed at 110 °C for 20 minutes. Next, phenethylammonium bromide (PEABr) with a concentration of 2 mg / mL in isopropanol (IPA) and dimethyl sulfoxide (DMSO) solution (volume ratio 200:1) was spin-coated on the top at 4000 rpm for 30 seconds and annealed at 110 °C for 5 minutes.

[0075] Subsequently, [6,6]-phenyl C61 butyric acid methyl ester (PCBM, purity 99%) and fullerene (C60, purity 99.5%) were spin-coated on the perovskite thin film as an electron transport layer (ETL) at a mass ratio of 4:1, with a spin-coating speed of 3000 rpm for 30 seconds and a temperature of 60 °C for 5 minutes.

[0076] Finally, under a vacuum condition of 2×10 −6 mbar (effective area of 0.1 cm 2 ), 100 nm of gold (Au) and 5 nm of chromium (Cr) were deposited by thermal evaporation to fabricate the device.

[0077] Test results: The photoelectric conversion efficiency of the inverted perovskite solar cell was 23.27%.

[0078] To illustrate the relevant performance of the solar cell provided by the present invention, it is described in conjunction with the accompanying drawings.

[0079] The surface of the perovskite film modified with TAS prepared in Example 2 (b) and the surface of the unmodified perovskite film prepared in Comparative Example 1 (a), as well as the cross-section of the perovskite film modified with TAS prepared in Example 2 (d) and the cross-section of the unmodified perovskite film prepared in Comparative Example 1 (c) were respectively analyzed by scanning electron microscopy (SEM). The results are as Figure 2 shown. Compared with Comparative Example 1, the grain size of the perovskite film in Example 2 was significantly increased and the arrangement was more compact, and the grain boundaries were reduced. The cross-sectional structure of the perovskite film modified with TAS in Example 2 showed a highly oriented vertical growth mode, which was manifested as a single grain uniformly extending along the entire film thickness direction, making the particle distribution of the perovskite layer more dense and regular, helping to suppress the defect state density at the grain boundaries, reducing the carrier recombination probability, increasing the carrier mobility and diffusion length, thereby optimizing the electrical and optical properties of the film and finally improving the photoelectric conversion efficiency of the device.

[0080] The inverted perovskite solar cells prepared in Examples 1, 2, 3 and Comparative Example 1 were respectively tested under the illumination conditions of AM 1.5G, 100 mW cm -2 for current-voltage ( J-V ). The results are as Figure 3 shown. Under the same scanning conditions, the devices of Examples 1, 2, and 3 modified with TAS showed significantly improved photovoltaic performance and obtained higher photoelectric conversion efficiencies. The device efficiency of Example 1 was 24.61%, the device efficiency of Example 2 was 25.41%, the device efficiency of Example 3 was 24.22%, and the device efficiency of Comparative Example 1 was 23.27%, indicating that the three-dimensional polymer buried interface modification provided by the present invention can improve the efficiency of inverted perovskite solar cells.

[0081] The inverted perovskite solar cells prepared in Example 2 and Comparative Example 1 were respectively subjected to an environmental stability test for 1000 hours in the atmosphere at room temperature of 50±5%. The test results are as Figure 4 shown. The photoelectric conversion efficiency of the device in Comparative Example 1 decreased rapidly after about 400 hours of the environmental stability test, and its performance loss exceeded 50% after 1000 hours. The device efficiency of Example 2 only showed a slight decrease, and its efficiency still remained at about 90.6% of the initial value after 1000 hours, indicating that the three-dimensional polymer buried interface modification provided by the present invention can improve the environmental stability of inverted perovskite solar cells.

[0082] The present invention describes preferred embodiments and their effects. However, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concepts. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention.

[0083] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried bottom interface modification, characterized in that, It includes a conductive glass, a hole transport layer, a three-dimensional polymer layer, a perovskite thin film, an electron transport layer, and an electrode that are sequentially stacked: The three-dimensional polymer layer is poly(vinylbenzyltripropylammonium hexafluorophosphate).

2. The highly efficient and stable inverted perovskite solar cell with three-dimensional polymer buried bottom interface modification according to claim 1, wherein The hole transport layer includes nickel oxide and [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid; the electron transport layer includes [6,6]-phenyl C61 butyric acid methyl ester and fullerene.

3. The highly efficient and stable inverted perovskite solar cell with three-dimensional polymer buried bottom interface modification according to claim 1, characterized in that The perovskite thin film is prepared from a perovskite precursor solution; wherein, the perovskite precursor solution is prepared by dissolving lead iodide, cesium iodide, lead bromide, methylammonium bromide, and formamidinium iodide in a mixed solvent of dimethylformamide and dimethyl sulfoxide and stirring well overnight.

4. The highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried bottom interface modification according to claim 1, wherein The thickness of the hole transport layer is 40 - 60 nm; the thickness of the three-dimensional polymer layer is 20 - 40 nm; the thickness of the perovskite thin film is 700 - 800 nm; the thickness of the electron transport layer is 40 - 60 nm.

5. The highly efficient and stable inverted perovskite solar cell with three-dimensional polymer buried bottom interface modification according to claim 1, wherein The poly(vinylbenzyltripropylammonium hexafluorophosphate) is prepared by reacting poly(benzylethyltripropylammonium chloride) with potassium hexafluorophosphate through an aqueous solution reaction.

6. A method for preparing a highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried bottom interface modification according to any one of claims 1 to 5, characterized in that, It includes the following steps: Perform surface treatment on the conductive glass; Prepare a hole transport layer on the conductive glass; Prepare a three-dimensional polymer layer on the hole transport layer: Dropwise add and spin-coat a dimethylacetamide solution of poly(vinylbenzyltripropylammonium hexafluorophosphate) on the hole transport layer, and anneal at 90 - 110 °C for 3 - 8 minutes to obtain the three-dimensional polymer layer; Prepare a perovskite thin film on the three-dimensional polymer layer; Prepare an electron transport layer on the perovskite thin film; Prepare an electrode on the electron transport layer; wherein, the concentration of the poly(vinylbenzyltripropylammonium hexafluorophosphate) is 0.05 - 0.15 mg / mL.

7. The preparation method of the highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried bottom interface modification according to claim 6, wherein, Preparing a hole transport layer on the conductive glass includes: Dropwise add a nickel oxide solution on the treated conductive glass, perform spin-coating, and heat at 150 - 180 °C for 8 - 12 minutes to obtain a nickel oxide thin film. Subsequently, spin-coat an ethanol solution of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid on the nickel oxide thin film, and then anneal at 90 - 110 °C for 8 - 12 minutes.

8. The preparation method of the highly efficient and stable inverted perovskite solar cell with a three-dimensional polymer buried bottom interface modification according to claim 6, wherein Preparing a perovskite thin film on the three-dimensional polymer layer includes: Spin-coat the perovskite precursor solution on the three-dimensional polymer layer, then anneal at 100 - 120 °C for 15 - 30 minutes. Then, spin-coat a mixed solution of isopropanol and dimethyl sulfoxide containing phenethylammonium bromide and anneal at 100 - 120 °C for 3 - 8 minutes; wherein, during the process of spin-coating the perovskite precursor solution, ethyl acetate is added drop by drop.

9. The preparation method of the highly efficient and stable inverted perovskite solar cell with three-dimensional polymer buried bottom interface modification according to claim 6, characterized in that, Preparing an electron transport layer on the perovskite thin film: includes: Spin-coat [6,6]-phenyl C61 butyric acid methyl ester and fullerene on the perovskite thin film as the electron transport layer, wherein the spin-coating speed is 2000 - 4000 rpm and the time is 20 - 40 seconds; After spin-coating, keep it at 55 - 65 °C for 3 - 6 minutes; Preparing an electrode on the electron transport layer includes: Under vacuum conditions, deposit gold and chromium as the electrode by thermal evaporation.

10. Application of the high-efficiency and stable inverted perovskite solar cell with a three-dimensional polymer buried bottom interface modification according to any one of claims 1 to 5 in the field of photovoltaics.

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