Multifunctional Dapsone Additives Prepare Efficient and Stable Perovskite Solar Cells

Perovskite solar cells (PSCs) have become more prominent in industrial development in recent years due to their excellent photovoltaic performances and cheap construction processes. Nevertheless, the dominant solution process for preparing perovskite light-absorbing films inevitably introduces some defects, which seriously hinder both the power conversion efficiency (PCE) and the long-term stability of PSCs. Consequently, manipulating the defects in perovskite films is an indispensable consideration for enhancing the devices' performances. Herein, an efficient, bifunctional dapsone (Dps) molecule, which has a sulfonic acid (O═S═O) group and two amino (−NH2) groups, was introduced into the MAPbI3 perovskite precursor to passivate the charged defects derived from uncoordinated Pb2+ and I–. Meanwhile, the Dps additive can slow the crystallization process to obtain a high-quality perovskite film. Consequently, PSCs with Dps additives achieved an enhanced PCE, from 16.45% to 20.30%, with long-term stability, maintaining over 76% of the initial PCE under air conditions (RH ≈ 25%, 25 °C) for 1000 h.