A method for preparing high-efficiency perovskite solar cells assisted by pre-protonated aminopyridine

Abstract

The present invention belongs to the technical field of perovskite solar cells, and provides a method for preparing high-efficiency perovskite solar cells assisted by pre-protonated aminopyridine. The method of the present invention is not only convenient, simple to operate, low in cost, and effective, but also solves the interface proton transfer behavior induced in the process of Lewis base passivation of interface defects. Compared with the commonly used strong alkaline Lewis base molecule passivation defects, this method constructs a 3D / 2D heterojunction perovskite film in situ on the basis of not damaging the original perovskite surface crystal structure, which not only passivates the interface defects and greatly improves the efficiency of PSCs, but also utilizes the intrinsic hydrophobic properties of low-dimensional perovskite crystals to improve the long-term stability of PSCs.

Description

Technical Field

[0001] The invention belongs to the technical field of perovskite solar cells and relates to a method for preparing a high-efficiency perovskite solar cell with the assistance of pre-protonated aminopyridine. Background Art

[0002] Organic-inorganic hybrid perovskite solar cells (PSCs) have attracted extensive research interest due to their excellent material properties. In just a few decades of development, their PCE has reached 25.5% [Nature 2021, 598, 444–450]. Given the ionic properties of perovskite materials, various defects will inevitably occur during the rapid crystallization process. In order to prepare high-quality polycrystalline perovskite films, these defects should be effectively passivated. The interface defects of polycrystalline perovskite films are 1-2 orders of magnitude more than the bulk defects, and most of the point defects in the perovskite bulk phase will also slowly migrate to the surface or grain boundaries of the perovskite film [Science 2020, 367, 1352-1358]. Therefore, the non-radiative recombination losses caused by interface defects are much greater than those of bulk defects. Studies have shown that inhibiting the non-radiative recombination at the interface between the perovskite / hole extraction layer through interface engineering is an effective strategy for preparing high-efficiency PSCs. Among them, Lewis bases are widely used as a simple and effective passivating agent in defect suppression engineering [J.Am.Chem.Soc.2019,141(14), 5781-5787]. The mechanism of action is that the Lewis base molecules pass through the uncoordinated Pb at the grain boundary or surface of the perovskite film. 2+ (Lewis acid) forms a coordination bond to generate a Lewis acid-base adduct to achieve the purpose of passivation. Due to the electron-donating nature of the Lewis base, in the passivation of Pb 2+ At the same time, it will also interact with the organic cations (methylamine ions or formamidinium ions) in the perovskite, inducing the transfer tendency of H protons in the perovskite from organic cations to passivators. In the perovskite crystal, due to the volatility of the organic molecules formed after the deprotonation of the organic ammonium salt, the perovskite structure will collapse, leading to the degradation of the device [Nat Commun 2016, 7, 13422]. Summary of the invention

[0003] The present invention provides a method for preparing high-efficiency perovskite solar cells with the assistance of pre-protonated aminopyridine, by pre-protonating aminopyridine molecules, regulating the interfacial proton transfer behavior induced by aminopyridine molecules in the process of passivating interfacial defects. On the basis of not damaging the original perovskite surface crystal structure, a three-dimensional / two-dimensional (3D / 2D) heterojunction perovskite film is constructed in situ, which not only passivates the interfacial defects and greatly improves the efficiency of PSCs, but also utilizes the intrinsic hydrophobic properties of low-dimensional perovskite crystals to improve the long-term stability of PSCs. This method realizes the performance regulation of Lewis base passivators in the preparation of high-efficiency PSCs.

[0004] The technical solution of the present invention:

[0005] A method for preparing high-efficiency perovskite solar cells with the assistance of pre-protonated aminopyridine, comprising the following steps:

[0006] Step (1), cleaning and treating the transparent conductive substrate;

[0007] Ultrasonic cleaning was performed with detergent solution, deionized water, anhydrous ethanol, and isopropanol for 10 to 30 minutes respectively;

[0008] Step (2), depositing an electron transport layer;

[0009] Spin coating the surface of the transparent conductive substrate cleaned in step (1) with a tin oxide nanoparticle hydrogel having a mass concentration of 2% to 5% by spin coating, and then annealing at 150 to 180° C. for 30 to 60 min to obtain a tin oxide electron transport layer having a thickness of 50 to 100 nm;

[0010] Step (3), pre-protonating aminopyridine;

[0011] Prepare an ethanol solution with a concentration of 5 to 10 mg / mL 4-aminopyridine, add dropwise a 57% aqueous solution of hydroiodic acid with a molar ratio of 1:1 to 4-aminopyridine in an ice-water bath, stir for 1 to 3 hours, remove excess ethanol by rotary evaporation, add ether for washing 3 to 5 times, and vacuum dry at 50 to 70° C. for 10 to 15 hours to obtain pre-protonated aminopyridine;

[0012] Step (4), preparation of 3D / 2D heterojunction perovskite light absorbing layer;

[0013] 1) Preparation of perovskite precursor solution: lead iodide is dissolved in solvent A to prepare solution A with a concentration of 0.7-1.5M, and stirred for 3-6h at a temperature of 25-35°C; organic ammonium salt is dissolved in solvent B to prepare solution B with a concentration of 0.8-1.3M, and then filtered with a filter membrane with a pore size of 0.22μm to obtain perovskite precursor solutions A and B;

[0014] 2) Preparation of a passivation solution: dissolving the preprotonated aminopyridine obtained in step (3) in solvent B to obtain a solution C having a concentration of 5 to 10 mg / mL, stirring at a temperature of 25 to 35° C. for 1 to 2 h, and then filtering with a filter membrane having a pore size of 0.22 μm to obtain a preprotonated aminopyridine solution;

[0015] 3) Deposition of 3D / 2D heterojunction perovskite light absorbing layer: Spin coating the solution A prepared in step 1) onto the tin oxide electron transport layer prepared in step (2) at a speed of 1000-3000 rpm / min, and immediately anneal at 70°C for 10-30s; Continue to spin coating the solution B at a speed of 1000-3000 rpm / min, and immediately anneal at 150°C for 5-15min, to generate a 3D perovskite light absorbing layer with a thickness of 500-1000nm; Then, spin coating the pre-protonated aminopyridine solution at a speed of 3000-6000 rpm / min onto the surface of the 3D perovskite light absorbing layer, and reacting the pre-protonated aminopyridine with excess lead iodide on the surface of the 3D perovskite light absorbing layer to generate 2D perovskite in situ, thereby preparing a 3D / 2D heterojunction perovskite light absorbing layer;

[0016] Step (5): Preparation of hole transport layer

[0017] A 50-100 mg / mL Spiro-OMeTAD chlorobenzene solution was prepared, filtered through a 0.22 μm pore size filter membrane, and then coated onto the surface of the 3D / 2D heterojunction perovskite light absorbing layer at a speed of 3000-6000 rpm / min;

[0018] Step (6): Preparation of metal counter electrode

[0019] The device prepared in the above steps is placed into a mask plate, and metal electrodes are evaporated in a vacuum evaporation chamber.

[0020] The transparent conductive substrate is fluorine-doped tin oxide transparent conductive glass, indium tin oxide transparent conductive glass, aluminum-doped zinc oxide transparent conductive glass, transparent indium tin oxide conductive film or transparent cadmium telluride conductive film.

[0021] The organic ammonium salt is one or a mixture of two or more of iodine methylamine, chloromethylamine, bromomethylamine and iodine methyl ether.

[0022] The solvent A is one of N,N-dimethylformamide and dimethyl sulfoxide or a mixture of the two; the solvent B is isopropanol.

[0023] The 2D and 3D perovskite material deposition methods include spin coating, spray coating, doctor blade coating, slot die coating, screen printing, etc.

[0024] Beneficial effects of the present invention: The method of the present invention is not only convenient, simple to operate, low in cost, and effective, but also solves the interfacial proton transfer behavior induced by the Lewis base passivation of interface defects. Compared with the commonly used strong alkaline Lewis base molecule passivation of defects, this method in situ constructs a 3D / 2D heterojunction perovskite film without damaging the original perovskite surface crystal structure, which not only passivates the interface defects and greatly improves the efficiency of PSCs, but also utilizes the intrinsic hydrophobic properties of low-dimensional perovskite crystals to improve the long-term stability of PSCs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a surface scanning electron microscope photo of a 3D / 2D perovskite material;

[0026] Figure 2 It is a complete schematic diagram of the device structure;

[0027] Figure 3 is the current-voltage curve of 3D / 2D perovskite cell;

[0028] Figure 4 This is a surface scanning electron micrograph of the unprotonated amine-modified perovskite material;

[0029] Figure 5 is the current-voltage curve of the unprotonated amine-modified perovskite cell;

[0030] Figure 6 This is a surface scanning electron microscope photo of a perovskite material modified with 10 mM 4-aminopyridine;

[0031] Figure 7 This is the current-voltage curve of 10 mM 4-aminopyridine modified perovskite solar cell. DETAILED DESCRIPTION

[0032] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0033] Embodiment 1:

[0034] A method for preparing high-efficiency perovskite solar cells with the assistance of pre-protonated aminopyridine, comprising the following steps:

[0035] Step (1), cleaning and treatment of the FTO substrate, ultrasonic cleaning with detergent aqueous solution, deionized water, anhydrous ethanol, and isopropanol for 15 minutes respectively, and then treating with UV-ozone for 10 minutes.

[0036] Step (2), depositing a tin oxide electron transport layer, by spin coating a tin oxide nanoparticle hydrogel with a mass concentration of 3% at a rotation speed of 3000 rpm / min on the surface of the FTO substrate cleaned in step (1), and then annealing at 150° C. for 40 minutes to obtain a tin oxide electron transport layer with a thickness of about 60 nm.

[0037] Step (3), pre-protonate aminopyridine, prepare a 2M 4-aminopyridine ethanol solution, add dropwise a 57% aqueous solution of hydroiodic acid in a molar ratio of 1:1 to 4-aminopyridine in an ice-water bath, stir for 2.5 hours, remove ethanol by rotary evaporation, add ether for washing three times, and vacuum dry at 60°C for 12 hours.

[0038] Step (4): Preparation of 3D / 2D heterojunction perovskite light absorbing layer

[0039] 1) Preparation of perovskite precursor solution: Lead iodide was dissolved in a mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide to prepare a solution A with a concentration of 1 M, wherein the mixed volume ratio of N, N-dimethylformamide and dimethyl sulfoxide was 9:1, and stirred at a temperature of 25°C for 5 hours, and methyl iodide, methyl iodide, and methyl chloroamine were dissolved in isopropanol at a molar ratio of 10:1:1 to prepare a solution B with a concentration of 1.2 M, and then filtered with a filter membrane with a pore size of 0.22 μm to obtain perovskite precursor solutions A and B;

[0040] 2) Preparation of pre-protonated aminopyridine solution: dissolving the material obtained in step (3) in isopropanol to obtain a solution C with a concentration of 10 mM, stirring at 25° C. for 1.5 h, and then filtering with a filter membrane with a pore size of 0.22 μm to obtain a pre-protonated aminopyridine solution;

[0041] 3) 3D / 2D heterojunction perovskite light absorbing layer deposition: drop 10μL / cm 2 The A solution was spin-coated on the tin oxide electron transport layer prepared in step (2) at a speed of 1500 rpm / min for 30 seconds, and then annealed on a 70°C hot plate for 30 seconds; after cooling to 25°C, it was rotated at a speed of 2000 rpm / min for 30 seconds, and 40 μL / cm 2 The B solution was immediately annealed on a 150°C heating table for 10 min after spin coating. Due to the reaction between the solutes in the A solution and the B solution, a 3D perovskite polycrystalline film with a thickness of 700 nm was formed. Then, 50 μL / cm 2 The C solution was dropped onto the surface of the 3D perovskite and spin-coated at a speed of 5000 rpm / min for 30 s. The pre-protonated aminopyridine reacted with the excess lead iodide on the surface of the 3D perovskite to in situ generate 2D perovskite to prepare a 3D / 2D heterojunction perovskite light-absorbing layer, such as Figure 1 Shown

[0042] Step (5): Preparation of hole transport layer

[0043] Prepare 1M Spiro-OMeTAD chlorobenzene solution, then add 17.5μL acetonitrile solution with a concentration of 520mg / mL Li-TFSI and 28.8μL 4-tert-butylpyridine as additives to prepare Spiro-OMeTAD hole transport layer precursor solution D. After shaking and dissolving, filter with a 0.22μm pore size filter membrane, and then drop 10μL / cm 2 The D solution was spin coated at a speed of 3000 rpm / min for 30 seconds and then coated on the surface of the perovskite light absorbing layer as a hole transport layer.

[0044] Step (6): Preparation of metal counter electrode

[0045] The multilayer film prepared in the above steps is placed into the mask and placed in a vacuum deposition chamber. - 4 After Pa, first The silver electrode is evaporated to a thickness of The device preparation is completed.

[0046] The schematic diagram of the device structure is as follows Figure 2 As shown, the prepared device was exposed to standard simulated sunlight AM1.5 G (100mW / cm 2 ), use standard silicon battery (B5-520) to calibrate the light intensity, use Keithley2460 instrument to test, the current-voltage test results are as follows Figure 3 The specific test results are shown in Table 1.

[0047] Embodiment 2:

[0048] A method for preparing high-efficiency perovskite solar cells with the assistance of pre-protonated aminopyridine, comprising the following steps:

[0049] Step (1), cleaning and treatment of the FTO substrate, ultrasonic cleaning with detergent aqueous solution, deionized water, anhydrous ethanol, and isopropanol for 15 minutes respectively, and then treating with UV-ozone for 10 minutes.

[0050] Step (2), depositing a tin oxide electron transport layer, by spin coating a tin oxide nanoparticle hydrogel with a mass concentration of 3% at a rotation speed of 3000 rpm / min on the surface of the FTO substrate cleaned in step (1), and then annealing at 150° C. for 40 minutes to obtain a tin oxide electron transport layer with a thickness of about 60 nm.

[0051] Step (3), pre-protonate aminopyridine, prepare a 2M 4-aminopyridine ethanol solution, add dropwise a 57% aqueous solution of hydroiodic acid in a molar ratio of 1:1 to 4-aminopyridine in an ice-water bath, stir for 2.5 hours, remove ethanol by rotary evaporation, add ether for washing three times, and vacuum dry at 60°C for 12 hours.

[0052] Step (4): Preparation of 3D / 2D heterojunction perovskite light absorbing layer

[0053] 1) Preparation of perovskite precursor solution: Lead iodide was dissolved in a mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide to prepare a solution A with a concentration of 1 M, wherein the mixed volume ratio of N, N-dimethylformamide and dimethyl sulfoxide was 9:1, and stirred at a temperature of 25°C for 5 hours, and methyl iodide, methyl iodide, and methyl chloroamine were dissolved in isopropanol at a molar ratio of 10:1:1 to prepare a solution B with a concentration of 1.2 M, and then filtered with a filter membrane with a pore size of 0.22 μm to obtain perovskite precursor solutions A and B;

[0054] 2) Preparation of pre-protonated aminopyridine solution: dissolving the material obtained in step (3) in isopropanol to obtain a solution C with a concentration of 5 mM, stirring at a temperature of 25° C. for 1.5 h, and then filtering with a filter membrane with a pore size of 0.22 μm to obtain a pre-protonated aminopyridine solution;

[0055] 3) 3D / 2D heterojunction perovskite light absorbing layer deposition: drop 10μL / cm 2 The A solution was spin-coated on the tin oxide electron transport layer prepared in step (2) at a speed of 1500 rpm / min for 30 seconds, and then annealed on a 70°C hot plate for 30 seconds; after cooling to 25°C, it was rotated at a speed of 2000 rpm / min for 30 seconds, and 40 μL / cm 2 The B solution was immediately annealed on a 150°C heating table for 10 min after spin coating. Due to the reaction between the solutes in the A solution and the B solution, a 3D perovskite polycrystalline film with a thickness of 700 nm was formed. Then, 50 μL / cm 2 The C solution was dropped onto the surface of the 3D perovskite and spin-coated at a speed of 5000 rpm / min for 30 s. The pre-protonated aminopyridine reacted with the excess lead iodide on the surface of the 3D perovskite to in situ generate 2D perovskite to prepare a 3D / 2D heterojunction perovskite light-absorbing layer, such as Figure 1 Shown

[0056] Step (5): Preparation of hole transport layer

[0057] Prepare 1M Spiro-OMeTAD chlorobenzene solution, then add 17.5μL acetonitrile solution with a concentration of 520mg / mL Li-TFSI and 28.8μL 4-tert-butylpyridine as additives to prepare Spiro-OMeTAD hole transport layer precursor solution D. After shaking and dissolving, filter with a 0.22μm pore size filter membrane, and then drop 10μL / cm 2 The D solution was spin coated at a speed of 3000 rpm / min for 30 seconds and then coated on the surface of the perovskite light absorbing layer as a hole transport layer.

[0058] Step (6): Preparation of metal counter electrode

[0059] The multilayer film prepared in the above steps is placed into the mask and placed in a vacuum deposition chamber. - 4 After Pa, first The silver electrode is evaporated to a thickness of The device preparation is completed. The device structure diagram is shown in Figure 2 As shown in the figure, the prepared device was exposed to standard simulated sunlight AM1.5 G (100mW / cm 2 ), use standard silicon battery (B5-520) to calibrate the light intensity, use Keithley2460 instrument to test, the current-voltage test results are as follows Figure 4 The specific test results are shown in Table 1.

[0060] Embodiment 3:

[0061] A method for preparing high-efficiency perovskite solar cells with the assistance of pre-protonated aminopyridine, comprising the following steps:

[0062] Step (1), cleaning and treatment of the FTO substrate, ultrasonic cleaning with detergent aqueous solution, deionized water, anhydrous ethanol, and isopropanol for 15 minutes respectively, and then treating with UV-ozone for 10 minutes.

[0063] Step (2), depositing a tin oxide electron transport layer, by spin coating a tin oxide nanoparticle hydrogel with a mass concentration of 3% at a rotation speed of 3000 rpm / min on the surface of the FTO substrate cleaned in step (1), and then annealing at 150° C. for 40 minutes to obtain a tin oxide electron transport layer with a thickness of about 60 nm.

[0064] Step (3), pre-protonate aminopyridine, prepare a 2M 4-aminopyridine ethanol solution, add dropwise a 57% aqueous solution of hydroiodic acid in a molar ratio of 1:1 to 4-aminopyridine in an ice-water bath, stir for 2.5 hours, remove ethanol by rotary evaporation, add ether for washing three times, and vacuum dry at 60°C for 12 hours.

[0065] Step (4): Preparation of 3D / 2D heterojunction perovskite light absorbing layer

[0066] 1) Preparation of perovskite precursor solution: Lead iodide was dissolved in a mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide to prepare a solution A with a concentration of 1 M, wherein the mixed volume ratio of N, N-dimethylformamide and dimethyl sulfoxide was 9:1, and stirred at a temperature of 25°C for 5 hours, and methyl iodide, methyl iodide, and methyl chloroamine were dissolved in isopropanol at a molar ratio of 10:1:1 to prepare a solution B with a concentration of 1.2 M, and then filtered with a filter membrane with a pore size of 0.22 μm to obtain perovskite precursor solutions A and B;

[0067] 2) Preparation of pre-protonated aminopyridine solution: dissolving the material obtained in step (3) in isopropanol to obtain a solution C with a concentration of 20 mM, stirring at a temperature of 25° C. for 1.5 h, and then filtering with a filter membrane with a pore size of 0.22 μm to obtain a pre-protonated aminopyridine solution;

[0068] 3) 3D / 2D heterojunction perovskite light absorbing layer deposition: drop 10μL / cm 2 The A solution was spin-coated on the tin oxide electron transport layer prepared in step (2) at a speed of 1500 rpm / min for 30 seconds, and then annealed on a 70°C hot plate for 30 seconds; after cooling to 25°C, it was rotated at a speed of 2000 rpm / min for 30 seconds, and 40 μL / cm 2 The B solution was immediately annealed on a 150°C heating table for 10 min after spin coating. Due to the reaction between the solutes in the A solution and the B solution, a 3D perovskite polycrystalline film with a thickness of 700 nm was formed. Then, 50 μL / cm 2 The C solution was dropped onto the surface of the 3D perovskite and spin-coated at a speed of 5000 rpm / min for 30 s. The pre-protonated aminopyridine reacted with the excess lead iodide on the surface of the 3D perovskite to in situ generate 2D perovskite to prepare a 3D / 2D heterojunction perovskite light-absorbing layer, such as Figure 1 Shown

[0069] Step (5): Preparation of hole transport layer

[0070] Prepare 1M Spiro-OMeTAD chlorobenzene solution, then add 17.5μL acetonitrile solution with a concentration of 520mg / mL Li-TFSI and 28.8μL 4-tert-butylpyridine as additives to prepare Spiro-OMeTAD hole transport layer precursor solution D. After shaking and dissolving, filter with a 0.22μm pore size filter membrane, and then drop 10μL / cm 2The D solution was spin coated at a speed of 3000 rpm / min for 30 seconds and then coated on the surface of the perovskite light absorbing layer as a hole transport layer.

[0071] Step (6): Preparation of metal counter electrode

[0072] The multilayer film prepared in the above steps is placed into the mask and placed in a vacuum deposition chamber. - 4 After Pa, first The silver electrode is evaporated to a thickness of The device preparation is completed. The device structure diagram is shown in Figure 2 As shown in the figure, the prepared device was exposed to standard simulated sunlight AM1.5 G (100mW / cm 2 ), use standard silicon battery (B5-520) to calibrate the light intensity, use Keithley2460 instrument to test, the current-voltage test results are as follows Figure 5 The specific test results are shown in Table 1.

[0073] Embodiment 4:

[0074] A perovskite solar cell using 4-aminopyridine as a passivating agent and a preparation method thereof, the steps are as follows:

[0075] Step (1), cleaning and treatment of the FTO substrate, ultrasonic cleaning with detergent aqueous solution, deionized water, anhydrous ethanol, and isopropanol for 15 minutes respectively, and then treating with UV-ozone for 10 minutes.

[0076] Step (2), depositing a tin oxide electron transport layer, by spin coating a tin oxide nanoparticle hydrogel with a mass concentration of 3% at a rotation speed of 3000 rpm / min on the surface of the FTO substrate cleaned in step (1), and then annealing at 150° C. for 40 minutes to obtain a tin oxide electron transport layer with a thickness of about 60 nm.

[0077] Step (3), preparation of 4-aminopyridine modified perovskite light absorbing layer

[0078] 1) Preparation of perovskite precursor solution: Lead iodide was dissolved in a mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide to prepare a solution A with a concentration of 1 M, wherein the mixed volume ratio of N, N-dimethylformamide and dimethyl sulfoxide was 9:1, and stirred at a temperature of 25°C for 5 hours, and methyl iodide, methyl iodide, and methyl chloroamine were dissolved in isopropanol at a molar ratio of 10:1:1 to prepare a solution B with a concentration of 1.2 M, and then filtered with a filter membrane with a pore size of 0.22 μm to obtain perovskite precursor solutions A and B;

[0079] 2) Preparation of 4-aminopyridine solution: 4-aminopyridine was dissolved in isopropanol to prepare a solution C with a concentration of 10 mM, stirred at 25° C. for 1.5 h, and then filtered through a filter membrane with a pore size of 0.22 μm to obtain a 4-aminopyridine solution;

[0080] 3) 4-aminopyridine modified perovskite light absorbing layer deposition: drop 10μL / cm 2 The A solution was spin-coated on the tin oxide electron transport layer prepared in step (2) at a speed of 1500 rpm / min for 30 seconds, and then annealed on a 70°C hot plate for 30 seconds; after cooling to 25°C, it was rotated at a speed of 2000 rpm / min for 30 seconds, and 40 μL / cm 2 The B solution was immediately annealed on a 150°C heating table for 10 min after spin coating. Due to the reaction between the solutes in the A solution and the B solution, a 3D perovskite polycrystalline film with a thickness of 700 nm was formed. Then, 50 μL / cm 2 The C solution was dripped onto the surface of the 3D perovskite and spin-coated at a speed of 5000 rpm / min for 30 s. After the cations in the 3D perovskite were subjected to a proton transfer reaction between 4-aminopyridine and the cations, the cations were reacted with excess PbI 2 The reaction generates 2D perovskite in situ, and the surface of 3D perovskite is covered with a light-absorbing layer of 2D perovskite, such as Figure 6 Shown

[0081] Step (5): Preparation of hole transport layer

[0082] Prepare 1M Spiro-OMeTAD chlorobenzene solution, then add 17.5μL acetonitrile solution with a concentration of 520mg / mL Li-TFSI and 28.8μL 4-tert-butylpyridine as additives to prepare Spiro-OMeTAD hole transport layer precursor solution D. After shaking and dissolving, filter with a 0.22μm pore size filter membrane, and then drop 10μL / cm 2 The D solution was spin coated at a speed of 3000 rpm / min for 30 seconds and then coated on the surface of the perovskite light absorbing layer as a hole transport layer.

[0083] Step (6): Preparation of metal counter electrode

[0084] The multilayer film prepared in the above steps is placed into the mask and placed in a vacuum deposition chamber. - 4 After Pa, first The silver electrode is evaporated to a thickness of The device preparation is completed. The device structure diagram is shown in Figure 2As shown in the figure, the prepared device was exposed to standard simulated sunlight AM1.5 G (100mW / cm 2 ), use standard silicon battery (B5-520) to calibrate the light intensity, use Keithley2460 instrument to test, the current-voltage test results are as follows Figure 7 The specific test results are shown in Table 1.

[0085] Table 1:

[0086]

Claims

1. A method for preparing high-efficiency perovskite solar cells with the assistance of pre-protonated aminopyridine, characterized in that: Here are the steps: Step (1), cleaning and treating the transparent conductive substrate; Ultrasonic cleaning was performed with detergent solution, deionized water, anhydrous ethanol, and isopropanol for 10 to 30 minutes respectively; Step (2), depositing an electron transport layer; Spin coating the tin oxide nanoparticle hydrogel with a mass concentration of 2% to 5% on the surface of the transparent conductive substrate cleaned in step (1) by spin coating, and then annealing at 150 to 180° C. for 30 to 60 minutes to obtain a tin oxide electron transport layer with a thickness of 50 to 100 nm; Step (3), pre-protonating aminopyridine; Prepare an ethanol solution with a concentration of 5 to 10 mg / mL 4-aminopyridine, add dropwise a 57% aqueous solution of hydroiodic acid with a molar ratio of 1:1 to 4-aminopyridine in an ice-water bath, stir for 1 to 3 hours, remove excess ethanol by rotary evaporation, add ether for washing 3 to 5 times, and vacuum dry at 50 to 70° C. for 10 to 15 hours to obtain pre-protonated aminopyridine; Step (4), preparation of 3D / 2D heterojunction perovskite light absorbing layer; 1) Preparation of perovskite precursor solution: lead iodide is dissolved in solvent A to prepare solution A with a concentration of 0.7-1.5M, and stirred for 3-6h at a temperature of 25-35°C; organic ammonium salt is dissolved in solvent B to prepare solution B with a concentration of 0.8-1.3M, and then filtered with a filter membrane with a pore size of 0.22μm to obtain perovskite precursor solutions A and B; 2) Preparation of a passivation solution: dissolving the preprotonated aminopyridine obtained in step (3) in solvent B to obtain a solution C having a concentration of 5 to 10 mg / mL, stirring at a temperature of 25 to 35° C. for 1 to 2 h, and then filtering with a filter membrane having a pore size of 0.22 μm to obtain a preprotonated aminopyridine solution; 3) Deposition of 3D / 2D heterojunction perovskite light absorbing layer: Spin coating the solution A prepared in step 1) onto the tin oxide electron transport layer prepared in step (2) at a speed of 1000-3000 rpm / min, and immediately anneal at 70°C for 10-30s; Continue to spin coating the solution B at a speed of 1000-3000 rpm / min, and immediately anneal at 150°C for 5-15min, to generate a 3D perovskite light absorbing layer with a thickness of 500-1000nm; Then, spin coating the pre-protonated aminopyridine solution at a speed of 3000-6000 rpm / min onto the surface of the 3D perovskite light absorbing layer, and reacting the pre-protonated aminopyridine with excess lead iodide on the surface of the 3D perovskite light absorbing layer to generate 2D perovskite in situ, thereby preparing a 3D / 2D heterojunction perovskite light absorbing layer; Step (5): Preparation of hole transport layer Prepare 50-100 mg / mL of Spiro-OMeTAD chlorobenzene solution, filter it with a 0.22 μm pore size filter membrane, and then apply it to the surface of the 3D / 2D heterojunction perovskite light absorbing layer at a speed of 3000-6000 rpm / min; Step (6), preparation of metal counter electrode The device prepared in the above steps is placed into a mask plate, and metal electrodes are evaporated in a vacuum evaporation chamber.

2. The method according to claim 1, characterized in that: The transparent conductive substrate is fluorine-doped tin oxide transparent conductive glass, indium tin oxide transparent conductive glass, aluminum-doped zinc oxide transparent conductive glass, transparent indium tin oxide conductive film or transparent cadmium telluride conductive film.

3. The method according to claim 1 or 2, characterized in that: The organic ammonium salt is one or a mixture of two or more of iodine methylamine, chloromethylamine, bromomethylamine and iodine methyl ether.

4. The method according to claim 1 or 2, characterized in that: The solvent A is one of N,N-dimethylformamide and dimethyl sulfoxide or a mixture of the two; the solvent B is isopropanol.

5. The method according to claim 3, characterized in that: The solvent A is one of N,N-dimethylformamide and dimethyl sulfoxide or a mixture of the two; the solvent B is isopropanol.

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