Zwitterion-Functionalized SnO2 Substrate Induced Sequential Deposition of Black-Phase FAPbI3 with Rearranged PbI2 Residue.Black-phase formamidinium lead iodide (FAPbI3 ) with narrow bandgap and high thermal stability has emerged as the most promising candidate for highly efficient and stable perovskite photovoltaics. 
THERM