Synergistic effect of the anti-solvent bath method and improved annealing conditions for high-quality triple cation perovskite thin films

Abstract

One step solution processing together with anti-solvent engineering is a tested route in producing high-quality perovskite films due to its simplicity and low fabrication costs. Commercialization of perovskites will require replacing the anti-solvent drip process and lowering annealing temperatures to decrease the energy payback time. In this work, we successfully replace the anti-solvent drip with the anti-solvent bath (ASB) method through balancing the methylammonium (MA) and formamidinium (FA) cations to produce high-quality cesium (Cs)/FA/MA triple cation perovskite films. Furthermore, the annealing parameters of Cs_0.05FA_0.16MA_0.79PbI_2.7Br_0.3 are enhanced to allow for a low-temperature fabrication process when paired with the ASB method. This resulted in the formation of remarkable films with micrometer grains and few defects. Self-powered photodetectors were constructed using the improved conditions, resulting in devices that exhibited a low dark current, an on/off ratio of >10³, and a rapid rise time of 12.4 μs. The conclusion of this work shows that ASB can be applied to triple cation perovskites and in using this method, the previously established optimal annealing temperature is lowered.