Surface-related properties of perovskite CH3NH3PbI3 thin films by aerosol-assisted chemical vapour deposition

Abstract

A modified three-step aerosol-assisted chemical vapour deposition process was used to grow dense and uniform CH₃NH₃PbI₃ thin films directly on borosilicate glass. The resulting photoluminescence spectrum was blue shifted with respect to its bandgap. X-ray photoelectron spectroscopy studies confirmed non-stoichiometric lead : iodine ratios within the films, due to decomposition of the CH₃NH₃PbI₃ layers over time into lead iodide and the release of ammonia and hydrogen iodide. The complex refractive index and dielectric function of the deposited thin films were determined by variable angle spectroscopic ellipsometry.