Organic solvent vapor treatment of lead iodide layers in the two-step sequential deposition of CH3NH3PbI3-based perovskite solar cells

Abstract

The two step sequential deposition of CH₃NH₃PbI₃-based perovskite solar cells has been modified by applying toluene and chlorobenzene vapors during the preparation of PbI₂ films leading to the growth of the PbI₂ grain size. PbI₂ films treated with these solvent vapors have more surface area with which CH₃NH₃I can react leading to a more desirable perovskite layer morphology. This resulted in a significant increase in the performance of the corresponding perovskite solar cell devices where the average power conversion efficiency was enhanced from 5.2% for the control device up to 8.4 and 10.2% for toluene and chlorobenzene-treated devices, respectively.