Towards Perovskite Vapor Transport Deposition: PbI2 Deposition and Modeling in a Close Space Vapor Transport Configuration

Interactions between temperature, pressure, and deposition rate are explored for the deposition of PbI 2 in a close space vapor transport (CSVT) geometry. The data presented here confirm that PbI 2 deposition occurs through diffusive mass transport based on strong correlations between the deposition rate and PbI 2 concentration gradient from the source and to the substrate. The calculated deposition rates from a one-dimensional diffusive mass transport model are found to be in good agreement with the experimentally-measured values. Additionally, the deposition temperature and pressure are found to strongly affect the morphology of equally-thick PbI 2 films, where higher temperature produces a rougher morphology and higher pressure leads to a more open grain structure.