Spidermen Strategy for Stable 24% Efficiency Perovskite Solar Cells

Abstract The interface energetics‐modification plays an important role in improving the power conversion efficiency (PCE) among the perovskite solar cells (PSCs). Considering the low carrier mobility caused by defects in PSCs, a double‐layer modification engineering strategy is adopted to introduce the “spiderman” NOBF 4 (nitrosonium tetrafluoroborate) between tin dioxide (SnO 2 and perovskite layers. NO + , as the interfacial bonding layer, can passivate the oxygen vacancy in SnO 2 , while BF 4 − can optimize the defects in the bulk of perovskite. This conclusion is confirmed by theoretical calculation and transmission electron microscopy (TEM). The synergistic effect of NO + and BF 4 − distinctly heightens the carrier extraction efficiency, and the PCE of PSCs is 24.04% with a fill factor (FF) of 82.98% and long‐term stability. This study underlines the effectiveness of multifunctional additives in improving interface contact and enhancing PCE of PSCs.