Improving the quality of perovskite based on lead acetate for efficient solar cell

Organometallic halide perovskite films based on lead iodide precursor often suffered from bad repeatability and the usage of large quantities of toxic solvents due to the need for an anti-solvent washing process. Lead acetate (Pb(Ac)(2)) precursor, by contrast, was more promising because of the needless of anti-solvent washing during the fabrication of perovskite films. However, the performance of perovskite solar cells (PSCs) needs to be improved. Here, we developed a simple strategy to improve the efficiency of PSCs by adding a small amount of dimethylsulfoxide (DMSO) into the precursor solution of perovskite. An increase in power conversion efficiency (PCE) of PSCs from 13.34% to 15.74% was achieved. It was found that with the addition of DMSO, a stable mesophase structure was formed, which significantly delayed the crystallization of perovskite during the spincoating of precursor solution, resulting in more uniform and dense perovskite films. The trap intensity and charge carrier mobility of the perovskite films were estimated. The charge carrier dynamic and the recombination in the PSCs were studied. Our method provided a convenient way to improve the performance of PSCs based on Pb(Ac)(2) precursor.