Growth of high quality CH3NH3PbI3 thin films prepared by modified dual-source vapor evaporation

In this work, a high quality CH3NH3PbI3 thin film prepared by modified dual-source vapor evaporation was proposed. An ultra-thin PbI2 layer was deposited firstly, and then CH3NH3I and PbI2 were evaporated simultaneously to form CH3NH3PbI3 thin film. The results show that flat, uniform, smooth, less porous and good crystallinity perovskite thin films without impure phase are formed by the modified dual-source vapor evaporation. The ratios of Pb/I accord with the nominal MAPbI3 stoichiometry and the band gaps are about 1.60 eV close to the theoretical value of 1.55 eV. The properties of CH3NH3PbI3 thin film fabricated by this method are suitable for perovskite solar cells applications.