Buried Interface Passivation Using Organic Ammonium Salts for Efficient Inverted CsMAFA Perovskite Solar Cell...

This study uses different doping ratios of CsCl and MACl dual additives to improve the quality of the perovskite, where CsCl reduces the perovskite trap density and increases the resistance of charge recombination, and MACl was used to improve the phase stability. Finally, the composition of Cs_0.1MA_0.09FA_0.81PbCl_0.14I_2.86 perovskite solar cell (PeSC) can achieve better open-circuit voltage (Voc), short-circuit current density (Jsc), and photoelectric conversion efficiency (PCE). To achieve a better PCE of PeSC, the use of organic ammonium salt butane-1,4-diammonium iodide (BDAI₂) to passivate the perovskite bottom surface (buried interface) can effectively suppress the formation of defects at the perovskite buried interface, obtain higher crystallinity, and thereby reduce the probability of carrier recombination. The Jsc, fill factor (FF), and PCE of the PeSC based on BDAI₂ passivation increased from 24.0 mA cm^-2, 74.1%, and 18.6% to 24.5 mA cm^-2, 79.9%, and 20.5%, respectively.