Characterization of Large-Energy-Bandgap Methylammonium Lead Tribromide (MAPbBr 3 ) Perovskite Solar Cells.

We have investigated the effects of the methylammonium bromide (MABr) content of the precursor solution on the properties of wide-bandgap methylammonium lead tribromide (MAPbBr 3 ) perovskite solar cells (PSCs). In addition, the anti-solvent process for fabricating MAPbBr 3 perovskite thin films was optimized. The MAPbBr 3 precursor was prepared by dissolving MABr and lead bromide (PbBr 2 ) in N,N-dimethylformamide and N,N-dimethyl sulfoxide. Chlorobenzene (CB) was used as the anti-solvent. We found that both the morphology of the MAPbBr 3 layer and the PSCs performance are significantly affected by the MABr content in perovskite precursor solution and anti-solvent dripping time. The best-performing device was obtained when the molar ratio of MABr:PbBr 2 was 1:1 and the CB drip time was 10 s. The best device exhibited a power conversion efficiency of 7.58%, short-circuit current density of 7.32 mA·cm -2 , open-circuit voltage of 1.30 V, and fill factor of 79.87%.