Preparation of phase-pure and stable formamidinium-based lead iodide (FAPbI3) perovskites is essential for fabricating high-performance perovskite solar cells (PSCs). Here, we report using very little CsPbBr3 perovskite (2%, molar ratio...
Controlling the grain size of the organic–inorganic perovskite thin films using thiourea additives now crossing 2 μm size with >20% power conversion efficiency.