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

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 ℃ 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. (author)