Effects of Lead Iodide Crystallization on Photovoltaic Performance of Perovskite Solar Cells by the Vapor-Solid Reaction Method.

The vapor-solid reaction method (VRM) is one of the promising techniques to prepare high-performance perovskite solar cells. Herein, PbI 2 precursor films were prepared by vacuum evaporation. It was found that the PbI 2 precursor films exhibit high crystallinity and orderly morphology at the substrate temperature of 110 °C. On this basis, the precursor films were prepared by VRM to obtain high-quality perovskite films and the power conversion efficiency (PCE) of perovskite solar cells (PSCs) devices reached 17.1%. In contrast, the PbI 2 film precursor was prepared on the substrate without being heated and the PCE of the final PSCs devices was only 13.04%.