Ternary-source vapor-phase deposition of CH 3 NH 3 PbI 3 polycrystalline thin films using CH 3 NH 2 and HI gas sources with PbI 2 solid source

Abstract We have investigated reaction processes of vacuum deposition of CH 3 NH 3 PbI 3 using CH 3 NH 3 I and PbI 2 solid sources. CH 3 NH 3 I decomposes to CH 3 NH 2 and HI at around 100 °C under usual vacuum deposition conditions. Therefore, CH 3 NH 3 I solid source can be replaced with CH 3 NH 2 and HI gas sources. We have demonstrated that high-quality CH 3 NH 3 PbI 3 polycrystalline thin films can be fabricated by ternary-source vacuum deposition using CH 3 NH 2 and HI gas sources combined with PbI 2 solid source. The newly developed ternary-source vapor-phase deposition technique is useful because of its high stability and controllability in deposition rates.