Perovskite precursor solution, perovskite thin film, preparation method and inverted perovskite photovoltaic module
By using composite additives and a two-stage annealing process, the grain boundary defect problem caused by MACl volatilization was solved, resulting in perovskite films with high crystallinity and low defect state density, which improved the open-circuit voltage and hydrothermal stability of inverted perovskite modules.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- WUXI ZHONGNENG OPTICAL STORAGE TECH CO LTD
- Filing Date
- 2026-03-27
- Publication Date
- 2026-06-05
AI Technical Summary
In the existing technology, when using MACl as an additive to prepare perovskite thin films, the volatilization rate is difficult to control, resulting in high grain boundary defect density, large open-circuit voltage loss, insufficient hydrothermal stability, and limited energy level matching optimization.
A composite additive consisting of methylammonium chloride and methylamine thiocyanate is used. Through a two-stage annealing process, vertical orientation growth is promoted and the nucleation rate is slowed down. The coordination effect between MASCN and Pb2+ is utilized to reduce the defect state density and enhance the interfacial contact performance.
It improves the open-circuit voltage and damp-heat stability of inverted perovskite modules, significantly enhances the crystallinity and density of perovskite films, and strengthens the long-term operational stability of devices.
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Figure CN122161330A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of perovskite solar cell technology, specifically relating to a perovskite precursor solution, a perovskite thin film, a preparation method, and an inverted perovskite photovoltaic module. Background Technology
[0002] Against the backdrop of continuously growing global energy demand and increasing emphasis on environmental protection, solar energy, as a clean and renewable energy source, has received widespread attention for its development and utilization. Perovskite solar cells (PSCs), with their unique advantages, have become a research hotspot in the photovoltaic field in recent years.
[0003] Perovskite solar cells are a type of third-generation solar cell that uses perovskite-type organometal halide semiconductors as light-absorbing materials. Due to their high photoelectric conversion efficiency and low manufacturing cost potential, they are considered an important direction for the development of next-generation photovoltaic technology. Perovskite solar cell structures are generally divided into two types: formal planar structures and inverted planar structures. Compared to formal structures, inverted (pin) structure perovskite solar cells have become the focus of commercial research due to their negligible hysteresis effect, good light stability, and ease of integration with tandem devices.
[0004] Perovskite materials possess excellent optical properties, exhibiting a high light absorption coefficient, enabling them to absorb a large number of photons even at very thin thicknesses, thus effectively converting light energy into electrical energy. The uniformity and density of perovskite thin films are crucial for their performance and applications; high-quality perovskite films are essential for fabricating efficient and stable devices. Currently, introducing additives into the precursor solution is a common strategy for controlling the crystallization process when preparing formamidine lead iodide (FAPbI3)-based perovskite thin films. Methylammonium chloride (MACl) is one of the most efficient crystallization aids available; it can reduce the crystallization energy of perovskite by forming a volatile mesophase, significantly promoting grain growth and obtaining micron-sized large-grained films. However, the current technology of using only MACl as an additive still presents some technical challenges.
[0005] The evaporation rate is difficult to control precisely. MACl evaporates relatively quickly during annealing, which can easily lead to micropores on the film surface or unhealed vacancy defects (such as V) deep within the grain boundaries. FA or V I These defects can become nonradiative recombination centers, limiting the device's open-circuit voltage (V). OC Further improvement of ).
[0006] Lack of sustained defect passivation capability. As a "sacrificial" additive, MACl is almost completely removed from the film after annealing, and cannot provide long-term passivation protection for defects generated during the use of the film, resulting in insufficient long-term stability of the device in humid and hot environments.
[0007] Energy level matching optimization is limited. It is difficult to achieve both controlled crystal growth and precise optimization of interface energy levels by simply controlling chloride ions.
[0008] Therefore, there is an urgent need to develop a new composite additive strategy that can retain the advantage of MACl in promoting large grain growth while effectively compensating for the defects left after its volatilization, thereby simultaneously improving the efficiency and stability of inverted perovskite modules. Summary of the Invention
[0009] The purpose of this invention is to provide a perovskite precursor solution, a perovskite thin film, a preparation method, and an inverted perovskite photovoltaic module, in order to solve the problems of high grain boundary defect density, large open-circuit voltage loss, and insufficient damp heat stability caused by simply using MACl as an additive in the preparation of existing perovskite thin films.
[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, a perovskite precursor solution comprises: a perovskite main salt, a composite additive, and an organic solvent. The composite additive is composed of methylammonium chloride and methylamine thiocyanate, and the perovskite main salt is FAPbI3.
[0011] Preferably, the molar ratio of methylammonium chloride to methylamine thiocyanate in the composite additive is (2-7):(1-2); the molar ratio of the total molar amount of the composite additive to the molar ratio of lead ions in the perovskite main salt is (0.1-0.5):1.
[0012] Preferably, the lead ion concentration in the perovskite precursor solution is (1.1~1.2) mmol / mL.
[0013] Preferably, the organic solvent is obtained by mixing the mixture with N-methylpyrrolidone in a volume ratio of (3-9):1, and the mixture is obtained by mixing N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of (6-8):1.
[0014] Secondly, the present invention provides a method for preparing a perovskite thin film, comprising the following steps: The perovskite precursor solution described above is spin-coated onto a substrate, followed by vacuum flash evaporation and annealing to obtain a perovskite thin film.
[0015] Preferably, the annealing process includes two-stage annealing: first, pre-annealing at 60–90 °C for 1–5 min, followed by main annealing at 100–150 °C for 10–30 min.
[0016] Preferably, the vacuum flash evaporation includes flashing to 3-200 Pa in 5-45 s and holding for 20-30 s.
[0017] Thirdly, the present invention provides a perovskite thin film, which is prepared by the perovskite thin film preparation method described above.
[0018] Fourthly, the present invention provides an inverted perovskite photovoltaic module, comprising a hole transport layer, a perovskite thin film, an electron transport layer and a buffer layer stacked together, wherein the perovskite thin film is the perovskite thin film as described above.
[0019] Preferably, the hole transport layer is at least one of PTAA, nickel oxide, and SAMs, the electron transport layer is a fullerene, the buffer layer is a BCP, and a metal electrode is disposed on the buffer layer.
[0020] The beneficial effects of this invention are: The method for preparing perovskite thin films of the present invention utilizes methylamine thiocyanate (MASCN) to partially replace MACl. While MACl promotes vertical orientation growth and increases grain size, the introduced MASCN can react with Pb. 2+ This creates a strong coordination effect, appropriately slowing down the nucleation rate. This synergistic effect of "promoting and slowing down" effectively balances the crystallization kinetics, eliminating micropores and grain boundary gaps caused by the rapid volatilization of MACl alone, resulting in a denser film.
[0021] The perovskite thin film of this invention has high crystallinity, low defect state density, and excellent interfacial contact properties, which can significantly improve the Vo of inversion perovskite modules. OC And its stability in damp heat. MASCN exhibits amphoteric properties, exhibiting both soft and hard acidic and basic characteristics, with trace amounts of residual SCN. - It can firmly adsorb onto uncoordinated Pb at grain boundaries and surfaces. 2+ At defect sites, the defect state density is significantly reduced, suppressing nonradiative recombination. The introduction of thiocyanate ions strengthens the perovskite lattice framework and inhibits ion migration; simultaneously, MASCN effectively relieves residual stress within the film.
[0022] The defect passivation effect of the perovskite thin film of this invention can increase the open-circuit voltage of the inversion device by 20–50 mV. Inversion perovskite photovoltaic modules fabricated based on this thin film exhibit excellent long-term operational stability under high temperature (85 °C) or high humidity conditions. Attached Figure Description
[0023] Figure 1 This is a scanning electron microscope image of the perovskite thin film of Example 1; Figure 2 This is a scanning electron microscope image of the perovskite thin film of Example 2; Figure 3 This is a scanning electron microscope image of the perovskite thin film in Example 3; Figure 4 The image shows a scanning electron microscope (SEM) image of the perovskite thin film in Comparative Example 1. Figure 5 This is a scanning electron microscope image of the perovskite thin film in Comparative Example 2. Detailed Implementation
[0024] The present invention will be further described below with reference to the embodiments and accompanying drawings.
[0025] In the embodiments of the present invention, a large-area FTO conductive glass with a size of 100 mm × 100 mm is used as the substrate.
[0026] Example 1 FTO substrate treatment: The FTO conductive glass was scribed with P1 lines using a laser with a wavelength of 1064 nm. The scribing width was 30-50 μm. Then, it was ultrasonically cleaned with detergent water, deionized water, acetone and isopropanol for 20 min each. It was dried with a nitrogen gun and then treated with UV-O3 for 15 min to obtain the FTO substrate.
[0027] Preparation of the hole transport layer: The FTO substrate was placed on a slit coating platform, which was preheated to 50 °C. Nickel oxide (NiO) was coated on the FTO substrate at a coating gap of 50 μm and a coating speed of 20 mm / s. x Nanoparticle ink. After coating, the FTO substrate was annealed in a 150 °C oven for 20 min to obtain a dense NiO layer with a thickness of 20–30 nm. x The layer is the hole transport layer.
[0028] Preparation of perovskite precursor solution: 1.2 mmol of perovskite main salt was dissolved in 1 mL of organic solvent, and 0.24 mmol of composite additive was added. The mixture was then stirred at 60 °C for 2 h and filtered to obtain the perovskite precursor solution. The perovskite main salt was obtained by reacting a mixture of formamidinium hydroiodate (FAI) and lead iodide (PbI2) in a 1:1 molar ratio. The organic solvent was a mixture of 0.8 mL of N,N-dimethylformamide (DMF), 0.1 mL of dimethyl sulfoxide (DMSO), and 0.1 mL of N-methylpyrrolidone (NMP). The composite additive consisted of 0.18 mmol of MACl and 0.06 mmol of MASCN.
[0029] Preparation of perovskite thin films: The perovskite precursor solution was slit-coated onto the hole transport layer. During slit-coating, the slit coating head height was set to 80 μm, and the coating speed was 25 mm / s. After coating, the substrate was rapidly transferred to a vacuum flash evaporator, where the pressure reached 3 Pa in 45 s and was maintained for 20 s. A two-stage annealing process was then performed: first, pre-annealing at 60 °C for 3 min, followed by main annealing at 100 °C for 20 min, yielding the perovskite thin film.
[0030] Fabrication of electron transport layer and top electrode: Fullerene and BCP were deposited on perovskite film by evaporation, followed by deposition of copper electrode with a thickness of 100 nm using a thermal evaporation coating machine.
[0031] Module interconnection: Using a 532 nm laser, lines are drawn on P2 and P3 to complete the series interconnection, thus obtaining the inverted perovskite photovoltaic module.
[0032] Example 2 FTO substrate treatment: The FTO conductive glass was scribed with P1 lines using a laser with a wavelength of 1064 nm. The scribing width was 30-50 μm. Then, it was ultrasonically cleaned with detergent water, deionized water, acetone and isopropanol for 20 min each. It was dried with a nitrogen gun and then treated with UV-O3 for 15 min to obtain the FTO substrate.
[0033] Preparation of the hole transport layer: The FTO substrate was placed on a slit coating platform, which was preheated to 50 °C. NiO was coated on the FTO substrate with a coating gap of 50 μm and a coating speed of 20 mm / s. x Nanoparticle ink. After coating, the FTO substrate was annealed in a 150 °C oven for 20 min to obtain a dense NiO layer with a thickness of 20–30 nm. x The layer is the hole transport layer.
[0034] Preparation of perovskite precursor solution: 1.2 mmol of perovskite main salt was dissolved in 1 mL of organic solvent, and 0.24 mmol of composite additive was added. The mixture was then stirred at 60 °C for 2 h and filtered to obtain the perovskite precursor solution. The perovskite main salt was obtained by reacting a mixture of FAI and PbI in a 1:1 molar ratio. The organic solvent was a mixture of 0.8 mL of DMF, 0.1 mL of DMSO, and 0.1 mL of NMP. The composite additive consisted of 0.21 mmol of MACl and 0.03 mmol of MASCN.
[0035] Preparation of perovskite thin films: The perovskite precursor solution was slit-coated onto the hole transport layer. During slit-coating, the slit coating head height was set to 80 μm, and the coating speed was 25 mm / s. After coating, the substrate was rapidly transferred to a vacuum flash evaporator, where the pressure reached 3 Pa in 45 s and was maintained for 20 s. A two-stage annealing process was then performed: first, pre-annealing at 60 °C for 3 min, followed by main annealing at 100 °C for 20 min, yielding the perovskite thin film.
[0036] Fabrication of electron transport layer and top electrode: Fullerene and BCP were deposited on perovskite film by evaporation, followed by deposition of copper electrode with a thickness of 100 nm using a thermal evaporation coating machine.
[0037] Module interconnection: Using a 532 nm laser, lines are drawn on P2 and P3 to complete the series interconnection, thus obtaining the inverted perovskite photovoltaic module.
[0038] Example 3 FTO substrate treatment: The FTO conductive glass was scribed with P1 lines using a laser with a wavelength of 1064 nm. The scribing width was 30-50 μm. Then, it was ultrasonically cleaned with detergent water, deionized water, acetone and isopropanol for 20 min each. It was dried with a nitrogen gun and then treated with UV-O3 for 15 min to obtain the FTO substrate.
[0039] Preparation of the hole transport layer: The FTO substrate was placed on a slit coating platform, which was preheated to 50 °C. NiO was coated on the FTO substrate with a coating gap of 50 μm and a coating speed of 20 mm / s. x Nanoparticle ink. After coating, the FTO substrate was annealed in a 150 °C oven for 20 min to obtain a dense NiO layer with a thickness of 20–30 nm. x The layer is the hole transport layer.
[0040] Preparation of perovskite precursor solution: 1.2 mmol of perovskite main salt was dissolved in 1 mL of organic solvent, and 0.24 mmol of composite additive was added. The mixture was then stirred at 60 °C for 2 h and filtered to obtain the perovskite precursor solution. The perovskite main salt was obtained by reacting a mixture of FAI and PbI₂ in a 1:1 molar ratio. The organic solvent was a mixture of 0.8 mL of DMF, 0.1 mL of DMSO, and 0.1 mL of NMP. The composite additive consisted of 0.12 mmol of MACl and 0.12 mmol of MASCN.
[0041] Preparation of perovskite thin films: The perovskite precursor solution was slit-coated onto the hole transport layer. During slit-coating, the slit coating head height was set to 80 μm, and the coating speed was 25 mm / s. After coating, the substrate was rapidly transferred to a vacuum flash evaporator, where the pressure reached 3 Pa in 45 s and was maintained for 20 s. A two-stage annealing process was then performed: first, pre-annealing at 60 °C for 3 min, followed by main annealing at 100 °C for 20 min, yielding the perovskite thin film.
[0042] Fabrication of electron transport layer and top electrode: Fullerene and BCP were deposited on perovskite film by evaporation, followed by deposition of copper electrode with a thickness of 100 nm using a thermal evaporation coating machine.
[0043] Module interconnection: Using a 532 nm laser, lines are drawn on P2 and P3 to complete the series interconnection, thus obtaining the inverted perovskite photovoltaic module.
[0044] Example 4 FTO substrate treatment: The FTO conductive glass was scribed with P1 lines using a laser with a wavelength of 1064 nm. The scribing width was 30-50 μm. Then, it was ultrasonically cleaned with detergent water, deionized water, acetone and isopropanol for 20 min each. It was dried with a nitrogen gun and then treated with UV-O3 for 15 min to obtain the FTO substrate.
[0045] Preparation of the hole transport layer: The FTO substrate was placed on a slit coating platform, which was preheated to 50 °C. NiO was coated on the FTO substrate with a coating gap of 50 μm and a coating speed of 20 mm / s. x Nanoparticle ink. After coating, the FTO substrate was annealed in a 150 °C oven for 20 min to obtain a dense NiO layer with a thickness of 20–30 nm. x The layer is the hole transport layer.
[0046] Preparation of perovskite precursor solution: 1.2 mmol of perovskite main salt was dissolved in 1 mL of organic solvent, and 0.6 mmol of composite additive was added. The mixture was then stirred at 60 °C for 2 h and filtered to obtain the perovskite precursor solution. The perovskite main salt was obtained by reacting a mixture of FAI and PbI₂ in a 1:1 molar ratio; the organic solvent was a mixture of 0.75 mL DMF, 0.1 mL DMSO, and 0.15 mL NMP; the composite additive consisted of 0.36 mmol of MACl and 0.24 mmol of MASCN.
[0047] Preparation of perovskite thin films: The perovskite precursor solution was slit-coated onto the hole transport layer. During slit-coating, the slit coating head height was set to 80 μm, and the coating speed was 25 mm / s. After coating, the substrate was rapidly transferred to a vacuum flash evaporator, where the pressure reached 3 Pa in 45 s and was maintained for 20 s. A two-stage annealing process was then performed: first, pre-annealing at 60 °C for 1 min, followed by main annealing at 150 °C for 10 min, yielding the perovskite thin film.
[0048] Fabrication of electron transport layer and top electrode: Fullerene and BCP were deposited on perovskite film by evaporation, followed by deposition of copper electrode with a thickness of 100 nm using a thermal evaporation coating machine.
[0049] Module interconnection: Using a 532 nm laser, lines are drawn on P2 and P3 to complete the series interconnection, thus obtaining the inverted perovskite photovoltaic module.
[0050] Example 5 FTO substrate treatment: The FTO conductive glass was scribed with P1 lines using a laser with a wavelength of 1064 nm. The scribing width was 30-50 μm. Then, it was ultrasonically cleaned with detergent water, deionized water, acetone and isopropanol for 20 min each. It was dried with a nitrogen gun and then treated with UV-O3 for 15 min to obtain the FTO substrate.
[0051] Preparation of the hole transport layer: The FTO substrate was placed on a slit coating platform, which was preheated to 50 °C. NiO was coated on the FTO substrate with a coating gap of 50 μm and a coating speed of 20 mm / s. x Nanoparticle ink. After coating, the FTO substrate was annealed in a 150 °C oven for 20 min to obtain a dense NiO layer with a thickness of 20–30 nm. x The layer is the hole transport layer.
[0052] Preparation of perovskite precursor solution: 1.1 mmol of perovskite main salt was dissolved in 1 mL of organic solvent, and 0.3 mmol of composite additive was added. The mixture was then stirred at 60 °C for 2 h and filtered to obtain the perovskite precursor solution. The perovskite main salt was obtained by mixing FAI and PbI₂ in a 1:1 molar ratio; the organic solvent was obtained by mixing 0.65 mL of DMF, 0.1 mL of DMSO, and 0.25 mL of NMP; the composite additive consisted of 0.25 mmol of MACl and 0.05 mmol of MASCN.
[0053] Preparation of perovskite thin films: The perovskite precursor solution was slit-coated onto the hole transport layer. During slit-coating, the slit coating head height was set to 80 μm, and the coating speed was 25 mm / s. After coating, the substrate was rapidly transferred to a vacuum flash evaporator, where the pressure reached 100 Pa in 25 s and was maintained for 20 s. A two-stage annealing process was then performed: first, pre-annealing at 90 °C for 5 min, followed by main annealing at 125 °C for 30 min, yielding the perovskite thin film.
[0054] Fabrication of electron transport layer and top electrode: Fullerene and BCP were deposited on perovskite film by evaporation, followed by deposition of copper electrode with a thickness of 100 nm using a thermal evaporation coating machine.
[0055] Module interconnection: Using a 532 nm laser, lines are drawn on P2 and P3 to complete the series interconnection, thus obtaining the inverted perovskite photovoltaic module.
[0056] Comparative Example 1 FTO substrate treatment: The FTO conductive glass was scribed with P1 lines using a laser with a wavelength of 1064 nm. The scribing width was 30-50 μm. Then, it was ultrasonically cleaned with detergent water, deionized water, acetone and isopropanol for 20 min each. It was dried with a nitrogen gun and then treated with UV-O3 for 15 min to obtain the FTO substrate.
[0057] Preparation of the hole transport layer: The FTO substrate was placed on a slit coating platform, which was preheated to 50 °C. Nickel oxide (NiO) was coated on the FTO substrate at a coating gap of 50 μm and a coating speed of 20 mm / s. x Nanoparticle ink. After coating, the FTO substrate was annealed in a 150 °C oven for 20 min to obtain a dense NiO layer with a thickness of 20–30 nm. x The layer is the hole transport layer.
[0058] Preparation of the perovskite precursor solution: 1.2 mmol of the perovskite main salt was dissolved in 1 mL of organic solvent, 0.24 mmol of MACl was added, and the mixture was stirred at 60 °C for 2 h and then filtered to obtain the perovskite precursor solution. The perovskite main salt was a mixture of formamidinium hydroiodate (FAI) and lead iodide (PbI2) in a 1:1 molar ratio; the organic solvent was a mixture of 0.9 mL of N,N-dimethylformamide (DMF), 0.1 mL of dimethyl sulfoxide (DMSO), and 0.1 mL of N-methylpyrrolidone (NMP).
[0059] Preparation of perovskite thin films: The perovskite precursor solution was slit-coated onto the hole transport layer. During slit-coating, the slit coating head height was set to 80 μm, and the coating speed was 25 mm / s. After coating, the substrate was rapidly transferred to a vacuum flash evaporator, where the pressure reached 3 Pa in 45 s and was maintained for 20 s. A two-stage annealing process was then performed: first, pre-annealing at 60 °C for 3 min, followed by main annealing at 100 °C for 20 min, yielding the perovskite thin film.
[0060] Fabrication of electron transport layer and top electrode: Fullerene and BCP were deposited on perovskite film by evaporation, followed by deposition of copper electrode with a thickness of 100 nm using a thermal evaporation coating machine.
[0061] Module interconnection: Using a 532 nm laser, lines are drawn on P2 and P3 to complete the series interconnection, thus obtaining the inverted perovskite photovoltaic module.
[0062] Comparative Example 2 FTO substrate treatment: The FTO conductive glass was scribed with P1 lines using a laser with a wavelength of 1064 nm. The scribing width was 30-50 μm. Then, it was ultrasonically cleaned with detergent water, deionized water, acetone and isopropanol for 20 min each. It was dried with a nitrogen gun and then treated with UV-O3 for 15 min to obtain the FTO substrate.
[0063] Preparation of the hole transport layer: The FTO substrate was placed on a slit coating platform, which was preheated to 50 °C. Nickel oxide (NiO) was coated on the FTO substrate at a coating gap of 50 μm and a coating speed of 20 mm / s. x Nanoparticle ink. After coating, the FTO substrate was annealed in a 150 °C oven for 20 min to obtain a dense NiO layer with a thickness of 20–30 nm. x The layer is the hole transport layer.
[0064] Preparation of the perovskite precursor solution: 1.2 mmol of the perovskite main salt was dissolved in 1 mL of organic solvent, and 0.24 mmol of MASCN was added. The mixture was then stirred at 60 °C for 2 h and filtered to obtain the perovskite precursor solution. The perovskite main salt was a mixture of formamidinium hydroiodate (FAI) and lead iodide (PbI2) in a 1:1 molar ratio. The organic solvent was a mixture of 0.9 mL of N,N-dimethylformamide (DMF), 0.1 mL of dimethyl sulfoxide (DMSO), and 0.1 mL of N-methylpyrrolidone (NMP).
[0065] Preparation of perovskite thin films: The perovskite precursor solution was slit-coated onto the hole transport layer. During slit-coating, the slit coating head height was set to 80 μm, and the coating speed was 25 mm / s. After coating, the substrate was rapidly transferred to a vacuum flash evaporator, where the pressure reached 3 Pa in 45 s and was maintained for 20 s. A two-stage annealing process was then performed: first, pre-annealing at 60 °C for 3 min, followed by main annealing at 100 °C for 20 min, yielding the perovskite thin film.
[0066] Fabrication of electron transport layer and top electrode: Fullerene and BCP were deposited on perovskite film by evaporation, followed by deposition of copper electrode with a thickness of 100 nm using a thermal evaporation coating machine.
[0067] Module interconnection: Using a 532 nm laser, lines are drawn on P2 and P3 to complete the series interconnection, thus obtaining the inverted perovskite photovoltaic module.
[0068] The test results of the inverted perovskite photovoltaic modules prepared from the perovskite thin films of Examples 1-5 and Comparative Examples 1-2 are shown in Table 1. The photoelectric conversion efficiency stability of the inverted perovskite photovoltaic modules prepared from the perovskite thin films of Examples 1-5 and Comparative Examples 1-2 was tested under continuous illumination at 85 °C for 1000 h.
[0069] Table 1. Test results of inverted perovskite photovoltaic modules prepared from perovskite thin films of Examples 1-5 and Comparative Examples 1-2.
[0070] From Table 1, Figure 2 and Figure 3 As can be seen, when the proportion of MASCN in the composite additive is low, the on-state voltage of the inverted perovskite photovoltaic module prepared by the perovskite thin film in Example 2 decreases slightly. When the proportion of MASCN in the composite additive is high, the crystallization rate of the thin film in Example 3 is delayed, and SCN may appear. - Derivative residues affect charge transport, component J SC And FF decreased slightly.
[0071] From Table 1 and Figure 4 As can be seen from the data, when only MACl is used as the composite additive, the perovskite film in Comparative Example 1 is prone to generating a large number of micron-sized voids and film inhomogeneity due to uneven solvent precipitation, resulting in poor perovskite film density and a significant increase in leakage current of the inverted perovskite photovoltaic module.
[0072] From Table 1 and Figure 5 As can be seen from the data, the perovskite film in Comparative Example 2, due to the lack of MACl-assisted nucleation and crystal growth, exhibits an imbalance in film crystallization kinetics. The resulting intermediate phase film has excessively small grain size, leading to increased roughness of the perovskite film.SC and V OC The series resistance of the resulting inverted perovskite photovoltaic modules is significantly reduced, but the series resistance is relatively high.
[0073] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.
[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be determined by the claims. Similarly, any equivalent structural changes made based on the content of the present invention's specification shall also be included within the scope of protection of the present invention.
Claims
1. A perovskite precursor solution, characterized in that, include: Perovskite main salt, composite additives, organic solvents; The composite additive is composed of methylammonium chloride and methylamine thiocyanate, and the perovskite main salt is FAPbI3.
2. The perovskite precursor solution according to claim 1, characterized in that, The molar ratio of methylammonium chloride and methylamine thiocyanate in the composite additive is (2-7):(1-2); the total molar amount of the composite additive and the molar ratio of lead ions in the perovskite main salt are (0.1-0.5):
1.
3. The perovskite precursor solution according to claim 1, characterized in that, The lead ion concentration in the perovskite precursor solution is (1.1–1.2) mmol / mL.
4. The perovskite precursor solution according to claim 1, characterized in that, The organic solvent is obtained by mixing the mixture with N-methylpyrrolidone at a volume ratio of (3-9):1, and the mixture is obtained by mixing N,N-dimethylformamide and dimethyl sulfoxide at a volume ratio of (6-8):
1.
5. A method for preparing a perovskite thin film, characterized in that, Includes the following steps: The perovskite precursor solution as described in claim 1 is spin-coated onto a substrate, followed by vacuum flash evaporation and annealing to obtain a perovskite thin film.
6. The method for preparing perovskite thin films according to claim 5, characterized in that, The annealing process includes two-stage annealing: first, pre-annealing at 60–90 °C for 1–5 min, followed by main annealing at 100–150 °C for 10–30 min.
7. The method for preparing perovskite thin films according to claim 5, characterized in that, The vacuum flash evaporation includes flashing to 3-200 Pa in 5-45 s and holding for 20-30 s.
8. A perovskite thin film, characterized in that, The perovskite thin film was prepared using the preparation method described in any one of claims 5 to 7.
9. An inversion perovskite photovoltaic module, characterized in that, It includes a hole transport layer, a perovskite thin film, an electron transport layer and a buffer layer stacked together, wherein the perovskite thin film is the perovskite thin film as described in claim 8.
10. The inversion perovskite photovoltaic module according to claim 9, characterized in that, The hole transport layer is at least one of PTAA, nickel oxide, and SAMs, the electron transport layer is a fullerene, the buffer layer is a BCP, and a metal electrode is disposed on the buffer layer.