Multifunctional asymmetrical molecules for high-performance perovskite and organic solar cells

Abstract

Two asymmetrical molecules, namely IDT6CN-TM and IDT6CN-4F, are developed and used for multiple energy applications. The properties of these molecules, such as a wide absorption range, suitable energy levels, strong π–π stacking in a face-on orientation and high electron mobility, make them promising materials that can play different roles in both perovskite and organic solar cells (PVKSCs and OSCs). When working as electron transport materials (ETMs) and interfacial layer materials (ILMs), IDT6CN-TM provides MAPbI₃-based inverted PVKSCs with power conversion efficiencies (PCEs) of 18.36% (FF of 80%) and 19.79% (FF of 83%), respectively, which are among the highest PCEs and FFs reported so far. Moreover, the two compounds also show excellent performance as non-fullerene small molecule acceptors (NF-SMAs) of OSCs. PCEs of up to 12.40% (FF of 74.7%) are obtained in IDT6CN-TM-based OSCs. To the best of our knowledge, 12.40% is the highest PCE for OSCs based on NF-SMAs with thienyl side chains. These results demonstrate that the asymmetrical molecules are effective multifunctional materials for both PVKSCs and OSCs.