Self-Organized Growth of PbI-Based Layered Perovskite Quantum Well by Dual-Source Vapor Deposition

Oriented thin films of layered perovskite compounds (RNH3)2PbI4, which possess a quantum well structure where a two-dimensional semiconductor layer of PbI4 and an organic ammonium layer of RNH3 are alternately piled up, were found to grow in a self-organizing manner on fused quartz substrates through the simple dual-source vapor deposition of organic ammonium iodide RNH3I and lead iodide PbI2. The perovskite quantum-well films showed strong exciton absorption at around 2.4 eV and sharp exciton emission even at room temperature. Further, the X ray diffraction measurement on the vacuum-deposited films demonstrated that the layer structure of the vacuum-deposited film was oriented parallel to the film plane.