Study of perovskite CH3NH3PbI3 thin films under thermal exposure

Methyl-ammonium lead iodide-based perovskite materials have been extensively studied for applications in solar cells, which have reached high efficiencies of about 24% in the laboratory. However, being a hybrid (organic–inorganic) material, methyl-ammonium lead iodide can be affected by climatic conditions, such as humidity, light and temperature. While perovskite films have been synthesized, and annealing as part of the fabrication process has been reported, there have been, however, relatively few studies on the effects of temperature when the films, after synthesis, have been intentionally exposed to different temperatures. In this work, a study of the behaviour of perovskite films (MAPbI3) has been conducted exposing the films to different temperatures (25, 40, 50, 60 and 70°C) in small greenhouses. Homogeneous perovskite films were deposited by the anti-solvent method. The films were characterized by field-emission scanning electron microscopy, X-ray diffraction and optical absorption. The effects of temperature on film morphology, grain size and light absorbance are reported.