Quinoxaline-based nonfullerene acceptors with powerful core-functionalization ability enabling efficient solar energy utilization

Abstract

Solar energy utilization is a promising renewable technology for achieving efficient energy conversion. Nonfullerene acceptors (NFAs) have triggered wide interest in solar energy exploitation due to their multiple merits such as exceptional structural tunability and controllable optoelectronic properties. Quinoxaline-based acceptors have recently been applied in both photovoltaic and photocatalytic fields. In contrast to benzotriazole and benzothiadiazole units, the quinoxaline moiety enables powerful core-functionalization in NFAs, offering high structural modification possibilities. Additionally, it facilitates the construction of highly efficient NFAs with distinctive molecular packing modes and low reorganization energy. In this perspective, we systematically summarize the recent progress in the quinoxaline-based NFAs, including side-chain substitution, conjugation expansion, and construction of oligomeric and polymer acceptors. The altered cores of NFAs present superior modulation capabilities in terms of photoelectric properties, molecular packing, and blend morphology, resulting in reduced energy loss, enhanced V_OC, and improved efficiency in organic solar cells. These features provide novel opportunities for the advancement of solar energy utilization. Finally, the future directions are proposed from the perspectives of molecular design, material systems, cost reduction, stability, and practical applications. There is still significant development potential for advanced properties and applications enabled by quinoxaline-based acceptors. We anticipate that this perspective will pave the way and stimulate efforts to develop new quinoxaline-based acceptor materials for future applications.