Assessing the Impact of Ambient Fabrication Temperature on the Performance of Planar CH3NH3PbI3 Perovskite Solar Cells

The ambient fabrication temperature inside the glove box is found to play an important role in determining the overall power conversion efficiency in solar cells based on CH3NH3PbI3 (MAPI) hybrid organic-inorganic perovskites. We find that a variation of the ambient temperature of only 10 degrees C during the fabrication process has a crucial impact on both the reproducibility and the efficiency of the devices. Atomic Force Microscopy, XRD, UV-Vis absorption spectroscopy, and electroluminescence studies have been carried out to investigate the origin of this behavior. We conclude that the partial vapor pressure variation of the solvent impacts the crystallization process, inducing an increased density of traps within the bandgap of the perovskite.