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

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 CH3-NH3PbI2Br 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).