Effects of anti-solvent in the two-step fabrication of absorber layer in perovskite solar cells

Abstract Hybrid organic-inorganic perovskite materials, e.g., CH 3 NH 3 PbI 3 (MAPbI 3 ) have been used as photon absorber layer in the emerging solar cell technology. The two-step spin coating technique has been employed to fabricate the absorber films. It has been found that the use of anti-solvents plays a crucial role on the growth of the perovskite crystals. Chlorobenzene (CB) and Toluene (TO) were chosen as the anti-solvents that were applied after spin-coating of Methylammonium Iodide (MAI) solution in the second step of the two-step process. The amount and the elapsed time of the application of anti-solvents after spinning MAI solution were varied and studied for the crystal growth of perovskite films as well as the performance of the perovskite solar cells (PSCs). It was found that 50 ml of CB applied at 5 s after spinning MAI solution yielded the best solar cells parameters with the best efficiency of 16.8 %.