Texture of MAPbI₃ Layers Assisted by Chloride on Flat TiO₂ Substrates

In this paper, we use X-ray diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy to investigate the structural and morphological properties of methylammonium lead iodide (MAPbI 3 ) thin films deposited on flat TiO 2 substrates, as obtained with and without the use of chlorine precursors. We demonstrate that the presence of Cl precursors assists the growth of oriented MAPbI 3 domains along a specific growth direction. Such features are attributed to the proximity of the Cl species to the interface with the TiO 2 substrate.