A general non-CH3NH3X (X = I, Br) one-step deposition of CH3NH3PbX3 perovskite for high performance solar cells

Abstract

We demonstrate a facile non-CH₃NH₃I one-step fabrication of high quality CH₃NH₃PbI₃ perovskite via direct gas/solid deposition of spin coating HI + PbI₂ precursor solution in low concentration CH₃NH₂ atmospheres. This HI + PbI₂ precursor solution was prepared by direct addition of stoichiometric aqueous HI acid into PbI₂ DMF solution without any other chemicals. This novel one-step approach can be extended to fabricate different lead halide perovskites such as CH₃NH₃PbI₂Br and C₂H₅NH₂PbI₃ by spin coating HBr + PbI₂ precursor solution in CH₃NH₂ atmosphere or HI + PbI₂ in C₂H₅NH₂ atmosphere, respectively. In all, our novel one-step approach is a promising candidate for fabricating high performance perovskites by one-step reaction of gaseous CH₃NH₂ with HX and PbX₂ (X = I, Br).