Perovskite solar cells have had a rapid advance in photovoltaic devices. In 2009, an efficiency of 3.81% was recorded and in 2017 an efficiency of over 22% has been achieved. However, stability problems still arise due to it rapidly decomposing when exposed to the environment thus limiting its use and commercialization. Humidity has been an important factor. In the present work, the interaction between CH3NH3PbI3 and H2O vapor is studied. The perovskite was synthesized in two steps by the drop casting method. Uniform black-colored films were obtained. They were immediately subjected to an accelerated degradation using QUV Accelerated Weathering Tester Q-Lab. It was characterized by optic microscopy, UV-Vis spectroscopy, XRD and SEM. The effect of the PbI2/ CH3NH3I proportions was demonstrated regarding the stability after the accelerated degradation. The results showed that the perovskite degradation is reversible when it is no longer exposed to humidity.
Project CONACYT Problemas Nacionales 2015-01-1739.