Imidazole derivative molecule modified solar cell and preparation method thereof

Abstract

The invention discloses an imidazole derivative molecule modified solar cell and a preparation method thereof, and belongs to the technical field of solar cells. The cell sequentially comprises an ITO (Indium Tin Oxide) conductive glass layer, a nickel oxide passivation layer, a [4-(3, 6-dimethoxy-9H-carbazole-9-yl) butyl] phosphonic acid hole transport layer, an ITO (Indium Tin Oxide) conductive glass layer and a nickel oxide passivation layer from bottom to top, the thin film solar cell is characterized in that the thin film solar cell comprises a substrate, a metal Ag electrode layer, a Cs0.05 (FA0. 95MA0. 05) 0. 95Pb (I0. 95Br0. 05) 3 narrow-band gap perovskite thin film PVSK modified by 2-(2 ', 6'-dichloroanilino)-2-imidazoline, a (6, 6)-phenyl-C61-butyric acid methyl ester electron transport layer, a 2, 9-dimethyl-4, 7-biphenyl-1, 10-phenanthroline hole blocking layer and a metal Ag electrode layer; according to the scheme, perovskite defects are passivated through imidazole derivative molecules, double-interface passivation and crystallization regulation are achieved, the film quality is improved, and the crystal quality of the perovskite film is remarkably improved; due to effective passivation of the double interfaces, ion migration is obviously inhibited, the carrier transmission efficiency is effectively improved, and the moisture resistance of the perovskite thin film and the device stability are improved.

Description

Technical Field

[0001] The invention relates to an imidazole derivative molecule-modified solar cell and a preparation method thereof, belonging to the technical field of solar cells. Background Art

[0002] As the world develops, energy plays an indispensable role. Traditional energy sources, much of which are non-renewable and very limited, are increasingly used, exacerbating environmental and resource challenges. Photovoltaics, a future trend in renewable energy, offer advantages such as environmental friendliness, reproducibility, and ease of use. They can adjust the traditional energy mix, alleviate energy pressure, and meet the energy needs of sustainable human development. Over the past fifteen years and into the next twenty, my country has strongly supported the development of the photovoltaic industry.

[0003] Amid the historic shift from fossil fuels to clean energy, photovoltaics (PV) holds the greatest potential. Organic-inorganic halide hybrid perovskite (PSCs), a rising star in photovoltaic solar energy, boasts high photoelectric conversion efficiency (PCE), low manufacturing cost, and simplified fabrication processes. PSCs have attracted widespread attention due to their tunable band gap, strong visible light absorption, high carrier mobility, and low exciton binding energy. Although the PCE of organic-inorganic hybrid perovskite solar cells has approached 27%, significant obstacles remain: susceptibility to decomposition, high defect state density, and long-term instability. In multilayer PSCs, defects between the perovskite layer and the transport layer are unavoidable. Such defects reduce the carrier extraction rate and accelerate carrier recombination, thereby compromising the PSC's cell efficiency.

[0004] In order to solve the above problems, this paper proposes an imidazole derivative molecular modified solar cell and a preparation method thereof. Summary of the Invention

[0005] The present invention aims to reduce defects between the perovskite and transport layers, significantly suppressing non-radiative recombination in the perovskite, improving film quality, accelerating carrier transport, and achieving dual-interface passivation. Furthermore, the modification of imidazole derivative molecules helps improve the moisture resistance of the perovskite film and device stability.

[0006] In order to achieve the above technical effects, the present invention first provides an imidazole derivative molecule-modified solar cell, which comprises, from bottom to top, an ITO conductive glass sheet, a nickel oxide passivation layer, a [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid hole transport layer, a 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 narrow bandgap perovskite film, (6,6)-phenyl-C61-butyric acid methyl ester electron transport layer, 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline hole blocking layer and metal Ag electrode layer.

[0007] Another object of the present invention is to provide a method for preparing an imidazole derivative molecule-modified solar cell, comprising the following steps: (1) Pretreatment of ITO conductive glass sheet: clean the ITO conductive glass sheet, dry it and perform UV ozone treatment.

[0008] (2) Solution preparation: Prepare nickel oxide aqueous solution.

[0009] Prepare an ethanol solution of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid.

[0010] Preparation of 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3Narrow bandgap perovskite precursor solution.

[0011] Prepare a chlorobenzene solution of methyl (6,6)-phenyl-C61-butyrate.

[0012] Prepare an ethanol solution of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline.

[0013] (3) Spin coating: Spin coating nickel oxide aqueous solution on the pre-treated ITO conductive glass sheet, annealing after spin coating to obtain nickel oxide passivation layer, spin coating [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid ethanol solution on the nickel oxide passivation layer, annealing after spin coating to obtain hole transport layer; 2-(2',6'-dichloroaniline)-2-imidazoline modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05)3 narrow band gap perovskite precursor solution is spin-coated on the hole transport layer, and a drop of anti-solvent chlorobenzene solution is added during the high-speed spin-coating process. After spin-coating is completed, annealing is performed to obtain a narrow band gap perovskite film. A chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester is spin-coated on the narrow band gap perovskite film, and after spin-coating is completed, standing is performed to obtain a (6,6)-phenyl-C61-butyric acid methyl ester electron transport layer. An ethanol solution of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline is spin-coated on the (6,6)-phenyl-C61-butyric acid methyl ester electron transport layer, and after spin-coating is completed, standing is performed to obtain a 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline hole blocking layer.

[0014] (4) A portion of the spin-coated layer is scraped off to expose the ITO conductive glass sheet, and then a silver electrode is plated to obtain an imidazole derivative modified solar cell.

[0015] Preferably, in step (2), the 2-(2',6'-dichloroanilino)-2-imidazoline modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 narrow band gap perovskite precursor solution is prepared as follows: CsI, MABr2 (methylammonium bromide), FAI (formamidinium iodide), PbI2, PbBr2 and MACl (methylammonium chloride) are weighed according to the molar mass ratio, and then 2-(2',6'-dichloroanilino)-2-imidazoline is weighed. All the weighed substances are dissolved in a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide, and then stirred and filtered to obtain a 2-(2',6'-dichloroanilino)-2-imidazoline modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 narrow band gap perovskite precursor solution.

[0016] Preferably, the molar mass ratio of CsI, FAI (formamidinium iodide), MABr2 (methylammonium bromide), MACl (methylammonium chloride), PbI2 and PbBr2 is 0.05:0.9025:0.02375:0.02375:0.94875:0.05125; and the concentration of 2-(2',6'-dichloroanilino)-2-imidazoline in the mixed solvent is 0.4 mg / mL to 0.6 mg / mL.

[0017] Preferably, the volume molar mass ratio of the mixed solvent to CsI is: (1-0.18):(0.54-0.015), unit: μL:mol, and the volume ratio of N,N-dimethylformamide to dimethyl sulfoxide in the mixed solvent is: 2:1-8:1.

[0018] Preferably, in step (2), the concentration of nickel oxide in the aqueous solution of nickel oxide is 10-20 g / mL; the concentration of [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid in the ethanol solution is 0.5-1 mg / mL; the concentration of (6,6)-phenyl-C61-butyric acid methyl ester in the chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester is 20-30 mg / mL; the concentration of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline in the ethanol solution is 1-1.5 mg / mL.

[0019] Preferably, in step (3), the nickel oxide aqueous solution, the ethanol solution of [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid, the 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3The volume ratios of narrow bandgap perovskite precursor solution, chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester and ethanol solution of 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline are: (60~70):(40~50):(50~60):(40~60):(7~10).

[0020] Preferably, in step (3), the chlorobenzene solution and the 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3The volume ratio of the narrow bandgap perovskite precursor solution is (3~4):(1~2).

[0021] Preferably, the spin coating conditions of the nickel oxide passivation layer in step (3) are: static spin coating at a rotation speed of 2000-3000 rpm, a spin coating time of 30-35 s, and an acceleration of 1000-2000 rpm / s; and the annealing conditions are: annealing on a heating table at 120-150°C for 10-12 min.

[0022] Preferably, the spin coating conditions of the hole transport layer in step (3) are: static spin coating at a rotation speed of 5000-6000 rpm, a spin coating time of 30-35 s, and an acceleration of 3000-4000 rpm / s, and the annealing conditions are: annealing on a heating table at 100-110°C for 10-12 min.

[0023] Preferably, the low-speed spin coating conditions of the narrow-bandgap perovskite film in step (3) are: static spin coating at a low speed of 1000-2000 rpm, a spin coating time of 5-10 s, and an acceleration of 1000-2000 rpm / s; the high-speed spin coating conditions of the narrow-bandgap perovskite film are: static spin coating at a high speed of 4000-5000 rpm, a spin coating time of 30-35 s, and an acceleration of 2000-3000 rpm / s, and the annealing conditions are: annealing on a heating table at 100-110°C for 45-60 min.

[0024] Preferably, the spin coating conditions of the electron transport layer in step (3) are: static spin coating at a rotation speed of 1500-2500 rpm, an acceleration of 1000-2000 rpm / s, and a spin coating time of 50-55 s, and then standing for 15-20 minutes after the spin coating is completed.

[0025] Preferably, the spin coating conditions of the hole blocking layer in step (3) are: dynamic spin coating on the electron transport layer at a rotation speed of 6000-7000 rpm, an acceleration of 3000-4000 rpm / s, and a spin coating time of 25-30 s, and the layer is allowed to stand for 15-20 minutes after the spin coating is completed.

[0026] ITO conductive glass is made by coating a layer of indium tin oxide (commonly known as ITO) film on a soda-lime-based or silicon boron-based substrate glass using the magnetron sputtering method.

[0027] Beneficial effects of the present invention: (1) In the present invention, 2-(2',6'-dichloroanilino)-2-imidazoline is doped into the perovskite precursor solution. The molecule has multiple passivation sites, the -NH end can be connected to the mismatched Pb 2+ Ion combination, and the low concentration of electron cloud of -C=N can combine with free I3 - By forming hydrogen bonds, the two -CI groups can also coordinate with I, effectively passivating the defects formed by the mismatch between calcium Pb and I; the reduction of defects effectively improves the open circuit voltage and photoelectric conversion efficiency.

[0028] (2) In the present invention, the modification strategy of imidazole derivative molecules greatly inhibits the non-radiative recombination in perovskite, further stabilizes the lattice structure, and significantly improves the crystal quality of the perovskite film.

[0029] (3) In the present invention, the imidazole derivative molecules effectively treat the defects of the double interface, the ion migration is significantly suppressed, and the carrier transmission efficiency is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The photoelectric conversion efficiency (PCE) (Figure a) and short-circuit current (J) of the solar cells prepared in Example 1 and Comparative Example 1 are shown in Figure 1. SC ) (Figure b), open circuit voltage (V OC ) (Figure c) and fill factor (FF) (Figure d) statistical graphs.

[0031] Figure 2 Optimal JV curves of the solar cells prepared in Example 1 and Comparative Example 1.

[0032] Figure 3 These are TPC (Figure a) and TPV (Figure b) curves of the solar cells prepared in Example 1 and Comparative Example 1.

[0033] Figure 4 The following are XRD patterns of the solar cells prepared in Example 1 and Comparative Example 1.

[0034] Figure 5 These are XPS graphs of the solar cells prepared in Example 1 and Comparative Example 1.

[0035] Figure 6 PL (Figure a) and TRPL (Figure b) of the solar cells prepared in Example 1 and Comparative Example 1.

[0036] Figure 7 These are SEM surface images of the solar cells prepared in Example 1 and Comparative Example 1.

[0037] Figure 8 These are SEM bottom and cross-sectional views of the solar cells prepared in Example 1 and Comparative Example 1.

[0038] Figure 9 SCLC diagrams of defect state density of solar cells prepared in Example 1 and Comparative Example 1.

[0039] Figure 10 This is a humidity stability curve diagram of the solar cells prepared in Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0040] With reference to the accompanying drawings on which the embodiments of the application are illustrated, the technical solutions in the embodiments of the application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments of the application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the application.

[0041] The CAS numbers of the reagents used in the embodiments are as follows: The CAS number of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid is 2922526-56-3.

[0042] The CAS number of 2-(2',6'-dichloroanilino)-2-imidazoline is 4205-90-7.

[0043] The CAS number of (6,6)-phenyl-C61-butyric acid methyl ester is 160848-22-6.

[0044] The CAS number of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline is 4733-39-5.

[0045] Embodiment 1 A preparation method of a solar cell modified by an imidazole derivative molecule is described as follows: (1) Pre-treatment of ITO conductive glass sheet: the ITO conductive glass sheet is sequentially cleaned with a detergent, isopropyl alcohol, deionized water and anhydrous ethanol for 15 min under ultrasonic, and then is placed in a drying oven for drying for 25 min and in an ultraviolet ozone instrument for ultraviolet ozone treatment for 30 min.

[0046] (2) Preparation of solution: a nickel oxide aqueous solution is prepared at room temperature, and the concentration is 10 mg / mL.

[0047] The [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid ethanol solution is prepared by stirring uniformly and then standing at 55-65 (60) °C, and the concentration of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid in the obtained solution is 0.5 mg / mL.

[0048] The (6,6)-phenyl-C61-butyric acid methyl ester chlorobenzene solution is prepared, and the concentration of (6,6)-phenyl-C61-butyric acid methyl ester in the obtained solution is 20 mg / mL.

[0049] The 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline ethanol solution is prepared, and the concentration of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline in the obtained solution is 1 mg / mL.

[0050] Preparation of 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 narrow bandgap perovskite precursor solution, the specific steps are as follows: CsI, FAI (formamidine hydroiodide), MABr2 (methylammonium bromide), MACl (methylammonium chloride), PbI2, PbBr2 are weighed in a molar mass ratio of 0.05:0.9025:0.02375:0.02375:0.94875:0.05125, and 0.5 mg of 2-(2',6'-dichloroanilino)-2-imidazoline (Clonidine) is weighed and added to a mixed solvent dissolved in 800µL of N,N-dimethylformamide and 200µL of dimethyl sulfoxide to form a 1.4M CsI solution. 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3Narrow bandgap perovskite solution.

[0051] (3) Spin coating: 60 μL nickel oxide aqueous solution was statically spin-coated on the pretreated ITO conductive glass sheet at a speed of 2000 rpm, a spin coating time of 30 s, and an acceleration of 1000 rpm / s. After spin coating, it was placed on a 120°C heating table for annealing for 10 min, and then allowed to stand at room temperature to obtain a nickel oxide passivation layer; 40 μL of [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid ethanol solution was dropped onto the nickel oxide passivation layer and statically spin-coated at a speed of 5000 rpm, a spin coating time of 30 s, and an acceleration of 3000 rpm / s; after spin coating, it was placed on a 100°C heating table for annealing for 10 min to obtain a hole transport layer; 50 μL of 2-(2',6'-dichloroaniline)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05)3 The narrow bandgap perovskite precursor solution is spread on the upper layer of the hole transport layer, and static spin coating is performed at a low speed of 1000 rpm, a spin coating time of 5s, an acceleration of 1000 rpm / s and a high speed of 4000 rpm, a spin coating time of 30s, and an acceleration of 2000 rpm / s; 150 μL of anti-solvent chlorobenzene solution is added dropwise at a high speed of 23s; after the spin coating is completed, the spin-coated glass slide is immediately placed on a heating table at 100~110℃ for annealing for 60min, waiting for the perovskite film to crystallize on the glass slide, and after annealing, it is allowed to stand at room temperature; a narrow bandgap perovskite film is obtained; 40 μL of chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester is added dropwise to the glass slide with a passivation layer. The perovskite film of the electrochemical layer was statically spin-coated at a rotation speed of 1500 rpm, an acceleration of 1000 rpm / s, and a spin-coating time of 50 s, and then allowed to stand for 15 minutes to obtain an electron transport layer; 7 μL of 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline ethanol solution was dynamically suspended-coated on the electron transport layer at a rotation speed of 6000 rpm, an acceleration of 3000 rpm / s, and a spin-coating time of 25 s, and then allowed to stand for 15 minutes to obtain a hole blocking layer; part of the active layer was scraped off with tweezers to expose the ITO conductive glass layer, and then placed in a vacuum coating instrument to evaporate a 1200Å silver electrode. After all layers were spin-coated, an imidazole derivative molecule-modified solar cell was obtained.

[0052] Example 2 A method for preparing an imidazole derivative molecule-modified solar cell, the specific steps are as follows: (1) Pretreatment of ITO conductive glass sheet: The ITO conductive glass sheet was ultrasonically cleaned with detergent, isopropyl alcohol, deionized water and anhydrous ethanol in sequence for 20 minutes, then placed in a drying oven for drying for 32 minutes and placed in a UV ozone instrument for UV ozone treatment for 30 minutes.

[0053] (2) Solution preparation: Prepare an aqueous solution of nickel oxide at room temperature with a concentration of 10 mg / mL.

[0054] An ethanol solution of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid was prepared at 55°C by stirring uniformly and then allowing to stand. The concentration of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid in the resulting solution was 0.5 mg / mL.

[0055] A chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester was prepared to obtain a solution having a concentration of (6,6)-phenyl-C61-butyric acid methyl ester of 20 mg / mL.

[0056] An ethanol solution of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline was prepared, and the concentration of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline in the obtained solution was 1 mg / mL.

[0057] Preparation of 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 narrow bandgap perovskite precursor solution, the specific steps are as follows: CsI, FAI (formamidine hydroiodide), MABr2 (methylammonium bromide), MACl (methylammonium chloride), PbI2, PbBr2 are weighed in a molar mass ratio of 0.05:0.9025:0.02375:0.02375:0.94875:0.05125, and then 0.4 mg of 2-(2',6'-dichloroanilino)-2-imidazoline (Clonidine) is weighed and dissolved in a mixed solvent of 800µL N,N-dimethylformamide and 200µL dimethyl sulfoxide to form a 1.4M Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3Narrow bandgap perovskite solution.

[0058] (3) Spin coating: 70 μL nickel oxide aqueous solution was statically spin-coated on a pretreated ITO conductive glass sheet at a rotation speed of 3000 rpm, a spin coating time of 35 s, and an acceleration of 2000 rpm / s. After spin coating, it was placed on a 150°C heating table for annealing for 10 min, and then allowed to stand at room temperature to obtain a nickel oxide passivation layer; 50 μL of [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid ethanol solution was dropped onto the nickel oxide passivation layer and statically spin-coated at a rotation speed of 6000 rpm, a spin coating time of 30 s, and an acceleration of 4000 rpm / s; after spin coating, it was placed on a 110°C heating table for annealing for 10 min to obtain a hole transport layer; 60 μL of 2-(2',6'-dichloroaniline)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05)3 The narrow bandgap perovskite precursor solution is spread on the upper layer of the hole transport layer, and static spin coating is performed at a low speed of 1000 rpm, a spin coating time of 10s, an acceleration of 2000 rpm / s and a high speed of 5000 rpm, a spin coating time of 30s, and an acceleration of 3000 rpm / s; 150 μL of anti-solvent chlorobenzene solution is added dropwise at a high speed of 23s; after the spin coating is completed, the spin-coated glass slide is immediately placed on a heating table at 110°C for annealing for 60 minutes, waiting for the perovskite film to crystallize on the glass slide, and after the annealing is completed, it is allowed to stand at room temperature; a narrow bandgap perovskite film is obtained; 60 μL of chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester is added dropwise to the glass slide with a passivation layer The perovskite film was statically spin-coated at a rotation speed of 2500 rpm, an acceleration of 2000 rpm / s, and a spin-coating time of 55 s, and then allowed to stand for 20 min after the spin-coating was completed to obtain an electron transport layer; 10 μL of 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline ethanol solution was dynamically suspended-coated on the electron transport layer at a rotation speed of 7000 rpm, an acceleration of 4000 rpm / s, and a spin-coating time of 30 s, and then allowed to stand for 20 min after the spin-coating was completed to obtain a hole blocking layer; part of the active layer was scraped off with tweezers to expose the ITO conductive glass sheet, and then placed in a vacuum coating instrument to evaporate a 1200Å silver electrode. After all layers were spin-coated, an imidazole derivative molecule-modified solar cell was obtained.

[0059] Example 3 A method for preparing an imidazole derivative molecule-modified solar cell, the specific steps are as follows: (1) Pretreatment of ITO conductive glass sheet: The ITO conductive glass sheet was ultrasonically cleaned with detergent, isopropyl alcohol, deionized water and anhydrous ethanol in sequence for 15 to 20 minutes, then dried in a drying oven for 20 to 32 minutes and placed in an ultraviolet ozone instrument for ultraviolet ozone treatment for 30 minutes.

[0060] (2) Solution preparation: Prepare an aqueous solution of nickel oxide at room temperature with a concentration of 10 mg / mL.

[0061] An ethanol solution of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid was prepared at 55-65°C by stirring uniformly and then allowing to stand. The concentration of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid in the resulting solution was 0.6 mg / mL.

[0062] A chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester was prepared to obtain a solution having a concentration of (6,6)-phenyl-C61-butyric acid methyl ester of 20 mg / mL.

[0063] An ethanol solution of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline was prepared, and the concentration of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline in the obtained solution was 1 mg / mL.

[0064] Preparation of 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 narrow bandgap perovskite precursor solution, the specific steps are as follows: CsI, FAI (formamidine hydroiodide), MABr2, MACl (methylammonium chloride), PbI2, PbBr2 are weighed in a molar mass ratio of 0.05:0.9025:0.02375:0.02375:0.94875:0.05125, and then 0.6 mg of 2-(2',6'-dichloroanilino)-2-imidazoline (Clonidine) is weighed and dissolved in a mixed solvent of 800µL N,N-dimethylformamide and 200µL dimethyl sulfoxide to form a 1.4M Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3Narrow bandgap perovskite solution.

[0065] (3) Spin coating: 65 μL nickel oxide aqueous solution was statically spin-coated on the pretreated ITO conductive glass sheet at a rotation speed of 2000 rpm, a spin coating time of 30 s, and an acceleration of 1000 rpm / s. After spin coating, it was placed on a 120°C heating table for annealing for 10 min, and then allowed to stand at room temperature to obtain a nickel oxide passivation layer; 45 μL of [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid ethanol solution was dropped onto the nickel oxide passivation layer and statically spin-coated at a rotation speed of 5000 rpm, a spin coating time of 30 s, and an acceleration of 3000 rpm / s; after spin coating, it was placed on a 100°C heating table for annealing for 10 min to obtain a hole transport layer; 55 μL of 2-(2',6'-dichloroaniline)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05)3 The narrow bandgap perovskite precursor solution is spread on the upper layer of the hole transport layer, and static spin coating is performed at a low speed of 1000 rpm, a spin coating time of 5s, an acceleration of 1000 rpm / s and a high speed of 4000 rpm, a spin coating time of 30s, and an acceleration of 2000 rpm / s; 150 μL of anti-solvent chlorobenzene solution is added dropwise at a high speed of 23s; after the spin coating is completed, the spin-coated glass slide is immediately placed on a heating table at 100~110℃ for annealing for 60min, waiting for the perovskite film to crystallize on the glass slide, and after annealing, it is allowed to stand at room temperature; a narrow bandgap perovskite film is obtained; 50 μL of chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester is added dropwise to the glass slide with passivation. The electron transport layer was obtained by static spin coating on the perovskite film at a rotation speed of 1500 rpm, an acceleration of 1000 rpm / s and a spin coating time of 50 s. After the spin coating was completed, the film was allowed to stand for 15 minutes to obtain an electron transport layer; 7 (8) μL of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline ethanol solution was taken and dynamically suspended coated on the electron transport layer at a rotation speed of 6000 rpm, an acceleration of 3000 rpm / s and a spin coating time of 25 s. After the spin coating was completed, the film was allowed to stand for 15 minutes to obtain a hole blocking layer; part of the active layer was scraped off with tweezers to expose the ITO conductive glass sheet, and then placed in a vacuum coating instrument to evaporate a 1200Å silver electrode. After all layers were spin coated, an imidazole derivative molecule-modified solar cell was obtained.

[0066] The materials prepared in Examples 2 and 3 are similar to those prepared in Example 1.

[0067] Comparative Example 1 As a comparison, the difference between this comparative example and Example 1 is that: 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 The narrow bandgap perovskite film was not modified with 2-(2',6'-dichloroanilino)-2-imidazoline. The specific steps are as follows: (1) Pretreatment of ITO conductive glass sheet: The ITO conductive glass sheet was ultrasonically cleaned with detergent, isopropyl alcohol, deionized water and anhydrous ethanol in sequence for 15 minutes, then placed in a drying oven for 25 minutes and placed in a UV ozone instrument for UV ozone treatment for 30 minutes.

[0068] (2) Solution preparation: Prepare a nickel oxide aqueous solution at room temperature. The concentration of nickel oxide in the aqueous solution is 10 mg / mL.

[0069] An ethanol solution of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid was prepared at 55°C by stirring uniformly and then allowing to stand. The concentration of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid in the resulting solution was 0.5 mg / mL.

[0070] A chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester was prepared to obtain a solution having a concentration of (6,6)-phenyl-C61-butyric acid methyl ester of 20 mg / mL.

[0071] An ethanol solution of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline was prepared, and the concentration of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline in the obtained solution was 1 mg / mL.

[0072] Preparation of 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 Narrow bandgap perovskite precursor solution, the specific steps are as follows: CsI, FAI (formamidine hydroiodide), MABr2 (methylammonium bromide), MACl (methylammonium chloride), PbI2, PbBr2 with a molar mass ratio of 0.05:0.9025:0.02375:0.02375:0.94875:0.05125, dissolved in a mixed solvent of 800μL N,N-dimethylformamide and 200μL dimethyl sulfoxide to form a 1.4M Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3Narrow bandgap perovskite solution.

[0073] (3) Spin coating: 60 μL nickel oxide aqueous solution was statically spin-coated on the pre-treated ITO conductive glass sheet at a speed of 2000 rpm, a spin coating time of 30 s, and an acceleration of 1000 rpm / s. After spin coating, it was placed on a 120°C heating table for annealing for 10 min, and then allowed to stand at room temperature to obtain a nickel oxide passivation layer; 40 μL of [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid ethanol solution was dropped onto the nickel oxide passivation layer and the spin coating was continued at a speed of 5000 rpm. , spin coating time is 30s, acceleration is 3000rpm / s, static spin coating is performed; after spin coating, it is placed on a 100℃ heating table for annealing for 10min; a hole transport layer is obtained; a narrow band gap perovskite precursor solution is absorbed and spread on the upper layer of the hole transport layer, and static spin coating is performed at a low speed of 1000rpm, a spin coating time of 5s, an acceleration of 1000rpm / s and a high speed of 4000rpm, a spin coating time of 30s, and an acceleration of 2000rpm / s; at a high speed of 23s 150 μL of anti-solvent chlorobenzene solution was added dropwise; after the spin coating was completed, the spin-coated glass slide was immediately placed on a heating table at 100~110℃ for annealing for 45 minutes, waiting for the perovskite film to crystallize on the glass slide. After the annealing was completed, it was allowed to stand at room temperature to obtain a narrow band gap perovskite film; 40 μL of (6,6)-phenyl-C61-butyric acid methyl ester chlorobenzene solution was added dropwise on the perovskite film and statically spin-coated at a speed of 1500 rpm, an acceleration of 1000 rpm / s, and a spin coating time of 50 s. After the spin coating was completed, the perovskite film was statically spin-coated. The electron transport layer was obtained by standing for 15 minutes; 7 μL of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline ethanol solution was taken and dynamically suspended on the electron transport layer at a rotation speed of 6000 rpm, an acceleration of 3000 rpm / s, and a spin coating time of 25 s. After the spin coating, it was allowed to stand for 15 minutes to obtain a hole blocking layer; part of the active layer was scraped off with tweezers to expose the ITO conductive glass sheet, and then placed in a vacuum coating instrument to evaporate a 1200Å silver electrode. After all layers were spin-coated, a solar cell was obtained.

[0074] Effect monitoring The performance of the solar cells with different structures prepared in Example 1 and Comparative Example 1 was tested as follows: pass Figure 1 It can be seen that the open circuit voltage, short circuit current, fill factor and photoelectric conversion efficiency of perovskite devices have been greatly improved by introducing imidazole derivative molecules.

[0075] pass Figure 2 and Figure 3The introduction of imidazole derivatives significantly improved the photoelectric conversion efficiency of perovskite devices, from 22.47% to 25.33%. TPV and TPC results show that the perovskite devices modified with imidazole derivatives suppress charge recombination and reduce film defects, indicating that the introduction of imidazole derivatives facilitates carrier extraction.

[0076] pass Figure 4 It can be seen that the (110) peak intensity of the deposited perovskite film modified with imidazole derivative molecules is higher than that of the control group. The increase in peak intensity helps to increase the crystallinity of the perovskite film and is conducive to the formation of smoother and more ordered perovskite grains.

[0077] pass Figure 5 Compared to the control perovskite film, the perovskite film modified with imidazole derivatives exhibits Cl 2p peaks near 198.28eV and 201.72eV, demonstrating successful incorporation of the imidazole derivatives into the perovskite film. Furthermore, the electron cloud densities of both Pb 4f and I3 d changed after the imidazole derivatives were modified, demonstrating a strong interaction between the imidazole derivatives and the Pb and I ions, effectively passivating defects caused by the mismatch between Pb and I.

[0078] pass Figure 6 As can be seen, within the same emission wavelength range, the luminescence intensity of the perovskite film modified with imidazole derivatives is significantly higher than that of the control perovskite film, indicating that the imidazole derivatives effectively passivate the defects in the perovskite film and effectively suppress non-radiative recombination. Combined with TRPL, the perovskite film modified with imidazole derivatives also exhibits a longer carrier lifetime.

[0079] pass Figure 7 and Figure 8 It can be seen that after the addition of imidazole derivative molecules, the morphology of the perovskite film is more uniform and the grain size is significantly larger, proving that imidazole derivative molecules can promote the formation of a denser and more uniform self-assembled monolayer (SAM) of the grains. In addition, the modification of imidazole derivative molecules provides a good buried growth environment for the crystallization of perovskite. The SEM cross-section of the perovskite film modified with imidazole derivative molecules shows vertical crystal penetration, fewer disordered grains at the buried interface, and smaller grain boundaries, which is conducive to reducing trap density.

[0080] pass Figure 9 It can be seen that after the perovskite film is modified with imidazole derivative molecules, the perovskite film exhibits less hole and electron defect state density. Less defect state density is conducive to carrier migration, thereby showing a significantly improved open circuit voltage and better device performance.

[0081] pass Figure 10 It can be seen that after modification with imidazole derivative molecules, the humidity stability is better than that of the control device. The device modified with imidazole derivative molecules can still maintain more than 90% of the initial efficiency after being placed in a nitrogen glove box for 1500 hours. Previous characterization has proved that the film has less defect state density and stronger carrier extraction and transmission capabilities, which greatly improves the stability of the device.

Claims

1. An imidazole derivative molecule-modified solar cell, characterized in that: The imidazole derivative molecule modified solar cell comprises, from bottom to top, an ITO conductive glass sheet, a nickel oxide passivation layer, a [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid hole transport layer, a 2-(2',6'-dichloroanilino)-2-imidazoline modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 narrow bandgap perovskite thin film layer, (6,6)-phenyl-C61-butyric acid methyl ester electron transport layer, 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline hole blocking layer and metal Ag electrode layer.

2. The method for preparing a solar cell modified with imidazole derivative molecules according to claim 1, characterized in that: The following steps are involved: (1) Pretreatment of ITO conductive glass: clean the ITO conductive glass, dry it and perform UV ozone treatment; (2) Solution preparation: prepare an aqueous solution of nickel oxide; preparing an ethanol solution of [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid; Preparation of 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 narrow bandgap perovskite precursor solution; Prepare a chlorobenzene solution of methyl (6,6)-phenyl-C61-butyrate; Prepare an ethanol solution of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline; (3) Spin coating: Spin coating nickel oxide aqueous solution on the pre-treated ITO conductive glass sheet, annealing after spin coating to obtain nickel oxide passivation layer, spin coating [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid ethanol solution on the nickel oxide passivation layer, annealing after spin coating to obtain hole transport layer; 2-(2',6'-dichloroaniline)-2-imidazoline modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 A narrow-bandgap perovskite precursor solution is spin-coated on the hole transport layer, and an anti-solvent chlorobenzene solution is added dropwise during high-speed spin coating. After the spin coating is completed, annealing is performed to finally obtain a narrow-bandgap perovskite film; a chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester is spin-coated on the narrow-bandgap perovskite film, and after the spin coating is completed, the film is allowed to stand to obtain a (6,6)-phenyl-C61-butyric acid methyl ester electron transport layer; an ethanol solution of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline is spin-coated on the (6,6)-phenyl-C61-butyric acid methyl ester electron transport layer, and after the spin coating is completed, the film is allowed to stand to obtain a 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline hole blocking layer; (4) Scrape off part of the spin-coated layer to expose the ITO conductive glass sheet and then plate the silver electrode to finally obtain the imidazole derivative molecule-modified solar cell.

3. The method for preparing a solar cell modified with imidazole derivative molecules according to claim 2, characterized in that: The 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3 The preparation method of the narrow band gap perovskite precursor solution is as follows: weigh CsI, methylammonium bromide, formamidine hydroiodide, PbI2, PbBr2 and methylammonium chloride 1 in a molar mass ratio, and then weigh 2-(2',6'-dichloroanilino)-2-imidazoline, dissolve all the weighed substances in a mixed solvent consisting of N,N-dimethylformamide and dimethyl sulfoxide, stir and filter thoroughly to obtain 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3Narrow bandgap perovskite precursor solution.

4. The method for preparing a solar cell modified with imidazole derivative molecules according to claim 3, characterized in that: The molar mass ratio of CsI, formamidine hydroiodide, methylammonium bromide, methylammonium chloride, PbI2, and PbBr2 is 0.05:0.9025:0.02375:0.02375:0.94875:0.05125; the concentration of 2-(2',6'-dichloroanilino)-2-imidazoline in the mixed solvent is 0.4 mg / mL~0.6 mg / mL.

5. The method for preparing a solar cell modified with imidazole derivative molecules according to claim 3, characterized in that: The volume molar mass ratio of the mixed solvent to CsI is: (1-0.18):(0.54-0.015), unit: µL:mol, and the volume ratio of N,N-dimethylformamide to dimethyl sulfoxide in the mixed solvent is: 2:1-8:

1.

6. The method for preparing a solar cell modified with imidazole derivative molecules according to claim 2, characterized in that: The concentration of nickel oxide in the aqueous solution of nickel oxide in step (2) is: 1~1.5 mg / mL; the concentration of [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid in the ethanol solution is 0.5~1 mg / mL; the concentration of (6,6)-phenyl-C61-butyric acid methyl ester in the chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester is 20~30 mg / mL; the concentration of 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline in the ethanol solution is 1~1.5 mg / mL.

7. The method for preparing a solar cell modified with imidazole derivative molecules according to claim 2, characterized in that: In step (3), nickel oxide aqueous solution, [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid ethanol solution, 2-(2',6'-dichloroaniline)-2-imidazoline modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3The volume ratios of narrow bandgap perovskite precursor solution, chlorobenzene solution of (6,6)-phenyl-C61-butyric acid methyl ester and ethanol solution of 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline are: (60~70):(40~50):(50~60):(40~60):(7~10).

8. The method for preparing a solar cell modified with imidazole derivative molecules according to claim 2, characterized in that: In step (3), the chlorobenzene solution and 2-(2',6'-dichloroanilino)-2-imidazoline-modified Cs 0.05 (FA 0.95 MA 0.05 ) 0.95 Pb(I 0.95 Br 0.05 )3The volume ratio of the narrow bandgap perovskite precursor solution is (3~4):(1~2).

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