Synthesis and Photovoltaic Properties of Non-Fullerene Acceptors with Quinoxaline-Based Central Unit

Creation of novel heteroaromatic fused-ring structures is pivotal for the development of high-performance non-fullerene acceptors (NFAs) in organic photovoltaic (OPV) applications. In this study, we designed and synthesized a benzo[g]quinoxaline–thieno[3,2-b]thiophene (BQTT) fused structure as a novel central unit for an NFA. The BQTT-based NFA (BQTTIC) film exhibited broad absorption spanning the visible–near-infrared (vis–NIR) regions, extending up to 1000 nm. OPV devices based on BQTTIC paired with a conjugated donor polymer PBDB-T exhibited a power conversion efficiency of 4.12%. The strong amorphous nature of BQTTIC led to excessive mixing of BQTTIC and PBDB-T in the blend film, thereby reducing charge carrier transport properties and suppressing the OPV performance.