Nonhazardous Solvent Systems for Processing Perovskite Photovoltaics

Replacing toxic solvents with nonhazardous solvents is one of the key challenges for industrial scale commercialization of thin film perovskite photovoltaics. Here, nonhazardous solvent/alcohol/acid systems are presented for the single‐step deposition of pinhole‐free perovskite layers with combined lead halide precursors of Pb(CH3CO2)2·3H2O, PbCl2, and CH3NH3I. Comparable performance to standard hazardous inks is achieved: devices with 15.1% power conversion efficiency are demonstrated and maintain 13.5% tracked for 5 min at maximum power point. Blade coated 4 cm2 solar modules fabricated with highest performing device ink attain 11.9% in power conversion efficiency. Nonhazardous solvent‐alcohol‐acid systems are developed for single‐step deposition of perovskite photovoltaic layers, based on Hansen solubility parameters. The blade coating of 4 cm2 modules demonstrates the high yield and uniformity of the ink's coating capability.