Formation of CH3NH2-incorporated intermediate state in CH3NH3PbI3 hybrid perovskite thin film formed by sequential vacuum evaporation.

CH₃NH₃PbI₃ thin films were formed with various deposition rates of PbI₂ first layer using a sequential vacuum evaporation method (SVE) to understand the formation behavior. Under low PbI₂ deposition rates with 1 and 3 Å s⁻¹, the thin films did not form the hybrid perovskite structure. Over the 6 Å s⁻¹ deposition rate, the perovskite structure is observed with the remaining PbI₂ and an intermediate phase together. In the 10 Å s⁻¹, the intermediate phase is increased, and the CH₃NH₂ molecular defect is observed. The hybrid perovskite thin film formed by SVE is confirmed with tiny grains and CH₃NH₂-incorporated intermediate state. [ABSTRACT FROM AUTHOR]