The organic-inorganic halide hybrid perovskite solar cells (PSCs) constitute the most promising next-generation photovoltaics since, over the period of a decade, the power conversion efficiency (PCE) record increased from 9.7% to 25.7%. [1] The outstanding optoelectronics property of perovskite material benefits from its tunable bandgap energy, [2] high-light-absorption coefficient, [3] longcarrier-diffusion length, and high carrier mobility, [4] etc. Although perovskite materials possess an advantage in defect tolerance, the potential remains for development between practical efficiency values and theoretical PCE exceeding 30%. [5] In general terms, high-quality perovskite films are sensitive to moisture and require fabrication under an inert gas environment or at ambient featuring low humidity. Additionally, water erosion results in the degradation of perovskite and the formation of defects induced by ionic vacancy, especially at the grain boundaries and interfaces of the perovskite. [6] During the nucleation and growth of perovskite grains, defect-induced non-radiative recombination is inevitable. It has been reported that the trap density in polycrystalline perovskite films is about 10 15 % 10 17 cm À3 , while that is 10 11 %10 14 cm À3 in single-crystal perovskites. [7] This indicates that the defects are predominantly concentrated at grain boundaries and surfaces of perovskite films. Therefore, enhancing crystallization, enlarging crystal

We demonstrate a facile chemical bath deposition (CBD) of SnO2 films as excellent ETLs using a low temperature method (70 °C). The vacuum drying treatment and trichloropropylsilane (C3H7Cl3Si, Cl-Si) are employed for surface modification on SnO2 films due to the hygroscopicity of most metal oxides. The results reveal that the water molecules adsorbed on the CBD-SnO2 films can be desorbed by vacuum drying, and the hydrolysis products of Cl-Si can bond to SnO2 films through hydroxyl groups. Thus, the hydrophobicity of CBD-SnO2 is enhanced by employing the Cl-Si treatment, which is beneficial to improve the crystallinity of MAPbI3. The Cl-Si modified SnO2 films exhibit efficient electron extraction and hole blocking ability due to the higher electronic conduction band energy level than the pristine SnO2. Consequently, the MAPbI3 PSCs based on the hydrophobic Cl-Si/SnO2 exhibit a high PCE of 20.12% with low hysteresis, retaining 80% of the initial PCE after 500 h without any encapsulation at ambient condition. The 5 × 5 cm2 PSC modules prepared with this strategy achieve 15.24% efficiency (14.44% at forward scanning) with an aperture area of 10 cm2.

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Perovskite solar cells (PSCs) captivate tremendous interest thanks to high-efficiency and low-cost. Nevertheless, the planar PSCs are negatively affected by serious reflection loss usually because of the refractive index mismatch between the glass substrate and the air, which limits their light harvesting performance. Here, we report an investigation for highly efficient PSCs with light management by applying a structural antireflective film made of polydimethylsiloxane (PDMS) pyramidal texture. Machine learning is firstly used to predict planar (FAPbI3)0.95(MAPbBr2.2Cl0.8)0.05 PSC’ performance for an experimental guide. The experimental results show excellent agreement between the two. When the antireflective film is utilized in the present planar PSCs, an impressive light absorption enhancement is achieved, resulting in a significantly increased power conversion efficiency of up to 23.5%.

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