Reduction-Active Antisolvent: A Universal and Innovative Strategy of Further Ameliorating Additive Optimization for High Efficiency Perovskite Solar Cells

To further ameliorate current additive engineering ofperovskitesfor viable applications, the inherent limitations should be overcome;these include weakened coordination of the dopants to the [PbI6](4-) octahedra during crystallization andubiquity of ineffective bonding sites. Herein, we introduce a facilestrategy for synthesizing a reduction-active antisolvent. Washingwith reduction-active PEDOT:PSS-blended antisolvent substantiallyenhances the intrinsic polarity of the Lewis acid (Pb2+) in [PbI6](4-) octahedra, which causessignificant strengthening of the coordinate bonding between additivesand perovskite. Thus, coordination of the additive to the perovskitebecomes much stable. Additionally, the enhanced coordination abilityof Pb2+ can enhance the effective bonding sites and furtherenhance the efficacy of additive optimization to the perovskite. Here,we demonstrate five different additives as dopant bases and repeatedlyverify the universality of this approach. The photovoltaic performanceand stability of doped-MAPbI(3) devices are further improved,revealing the advanced potential of additive engineering.