Reproducible formation of uniform CH3NH3PbI3−xClx mixed halide perovskite film by separation of the powder formation and spin-coating process

To deposit uniform CH3NH3PbI3−xClx (MAPbI3−xClx) mixed halide perovskite film reproducibly, we separated the conventional process to formation of MAPbI3−xClx mixed halide perovskite powder by heat-treatment process and deposition of MAPbI3−xClx mixed halide perovskite film by single step spin-coating. The deviation of power conversion efficiency of MAPbI3−xClx mixed halide perovskite solar cells prepared by currently proposed method and conventional method was 13.75 ± 0.88% and 8.02 ± 1.65%, respectively, because more uniform MAPbI3−xClx mixed halide perovskite film could be reproducibly formed by separating the formation process of mixed halide perovskite powder and the single step spin-coating process.