Preparation and Characterization of Mixed Halide MAPbI3−xClx Perovskite Thin Films by Three‐Source Vacuum Deposition

Chloride has been extensively used in the preparation of metal halide perovskites such as methylammonium lead iodide (MAPbI3-xClx), but its persistence and role in solution-processed materials has not yet been rationalized. Multiple-source vacuum deposition of perovskites enables a fine control over the thin-film stoichiometry, and allows to incorporate chemical species irrespectively of their solubility. In this communication, we present the first example of mixed MAPbI3-xClx thin films prepared by three-source vacuum deposition using MAI, PbI2 and PbCl2 as precursors. The optoelectronic properties of the material are evaluated through photovoltaic and electro-/photo-luminescent characteri…