Impact of drying temperature on morphology and the crystallinity of ch3nh3pbi3 thin films

Abstract

Today, solar power is considered one of the most promising energy sources to satisfy the growing global energy demands and resolve the increasing energy crisis due to the reduction of fossil fuels. Solar cells are in continuous development; scientists focus more on discovering many ways to increase the photoelectric conversion efficiency of organic-inorganic perovskite solar cells. The quality of the perovskite film is directly affecting the performance of the device. The present work reports the influences of drying temperature on the film morphology and crystal structure of CH3NH3PbI3 thin film. A Two-step spin coating method was used to prepare the thin films and dried them at different drying temperatures to transform MAI.PbI 2 .DMSO into pure CH3NH3PbI3. X-ray diffraction data indicate the improvement of the crystallinity as the drying temperature rises. Furthermore, the grain size increase with the drying temperature forming larger grains at 150°C. The larger grains help increase the fill factor, decrease the crystal boundaries, and decrease the charge carrier recombination. UV visible absorption spectra reveal that the bandgap of corresponding CH 3 NH 3 PbI 3 thin films is around 1.55 eV.