Organic solar cell efficiency can be boosted through the strategic extension of the 2D conjugated core in nonfullerene acceptors (NFAs). In this work, two NFAs, IC-IQ2FDMBO-IC and IC2F-IQ2FDMBO-IC2F, were synthesized based on an asymmetric, fluorinated 2D-extended quinoxaline core featuring an unexpected N,N-dimethylmethanamine substitution. Compared to IC-IQ2FDMBO-IC, IC2F-IQ2FDMBO-IC2F exhibits deeper-lying energy levels and absorption extending to longer wavelengths due to its fluorinated terminal groups. When blended with PBDB-T, IC2F-IQ2FDMBO-IC2F forms more ordered and clearer fibril-like morphologies, resulting in an improved balance of charge carrier mobilities. Consequently, PBDB-T:IC2F-IQ2FDMBO-IC2F devices achieve a higher efficiency of 14.56%, surpassing devices based on PBDB-T:IC-IQ2FDMBO-IC. These results suggest that incorporating a fluorinated, asymmetric quinoxaline core is a rational design strategy for efficient NFAs.
Gopikrishna et al. (Wed,) studied this question.