Perovskite Solar Cells Fabricated by Using an Environmental Friendly Aprotic Polar Additive of 1,3-Dimethyl-2-imidazolidinone.

Perovskite solar cells (PSCs) have great potentials in photovoltaics due to their high power conversion efficiency and low processing cost. PSCs are usually fabricated from PbI2/dimethylformamide solution with some toxic additives, such as N-methyl pyrrolidone and hexamethylphosphoramide. Here, we use an environmental friendly aprotic polar solvent, 1,3-dimethyl-2-imidazolidinone (DMI), to fabricate perovskite films. By adding 10 vol% DMI in the precursor solution, high-quality perovskite films with smooth surface are obtained. By increasing annealing temperature from 100 to 130 °C, the average grain size of the perovskite increases from ~ 216 to 375 nm. As a result, the efficiency of the PSCs increases from 10.72 to 14.54%.