Cost-Effective Synthesis Method: Toxic Solvent-Free Approach for Stable Mixed Cation Perovskite Powders in Photovoltaic Applications.

Organometallic lead halide perovskite powders have gained widespread attention for their intriguing properties, showcasing remarkable performance in the optoelectronic applications. In this study, formamidinium lead iodide (α-FAPbI) microcrystals (MCs) is synthesized using retrograde solubility-driven crystallization. Additionally, methylammonium lead bromide (MAPbBr) and cesium lead iodide (δ-CsPbI) MCs are prepared through a sonochemical process, employing low-grade PbX (X = I & Br) precursors and an eco-friendly green solvent (γ-Valerolactone).