Deposition Kinetics and Compositional Control of Vacuum Processed CH3NH3PbI3 Perovskite

Halide perovskites have generated considerable research interest due to their excellent optoelectronic properties in the past decade. To ensure the formation of high quality semiconductors, the deposition process for the perovskite film is a critical issue. Vacuum based processing is considered a promising method allowing, in principle, also for large areas. One of the benefits of vacuum processing is the control over the film composition through the use of quartz crystal microbalances (QCMs) that in-situ monitor the rates of the components. In metal halide perovskites, however, one frequently employed component or precursor, CH3NH3I, exhibits non-standard sublimation properties. Here, we study in detail the sublimation properties of CH3NH3I and demonstrate that by correcting for its complex adsorption properties and by modeling the film growth, accurate predictions about the stoichiometry of the final perovskite film can be obtained.