Ternary-source vapor-phase deposition of CH₃NH₃PbI₃ polycrystalline thin films using CH₃NH₂ and HI gas sources with PbI₂ solid source

Abstract We have investigated reaction processes of vacuum deposition of CH3NH3PbI3 using CH3NH3I and PbI2 solid sources. CH3NH3I decomposes to CH3NH2 and HI at around 100 °C under usual vacuum deposition conditions. Therefore, CH3NH3I solid source can be replaced with CH3NH2 and HI gas sources. We have demonstrated that high-quality CH3NH3PbI3 polycrystalline thin films can be fabricated by ternary-source vacuum deposition using CH3NH2 and HI gas sources combined with PbI2 solid source. The newly developed ternary-source vapor-phase deposition technique is useful because of its high stability and controllability in deposition rates.