Synthesis of Geminal Dibromovinyl Asymmetrically Modified Nonfullerene Acceptors and Their Photovoltaic Properties

A nonfullerene acceptor (NFA), ACHV, is designed and synthesized by introducing a novel 2,2-dibromovinyl substituent onto the central quinoxaline unit. Compared with the control acceptor ACHM, the 2,2-dibromovinyl group profoundly modulates the electrostatic potential distribution, dipole moment, light-harvesting characteristics, and aggregation behavior of the acceptor ACHV. Consequently, organic solar cells (OSCs) based on ACHV achieve a power conversion efficiency (PCE) of 17.43% with simultaneously enhanced V_oc and FF without sacrificing J_sc. This work highlights a potential molecular design strategy for efficient OSCs.