Аннотация:The development of novel non-fullerene small-molecule acceptors (NFAs) with a simplechemical structure for high-performance organic solar cells (OSCs) remains an urgent researchchallenge to enable their upscaling and commercialization. In this work, we report on the synthesis and comprehensive investigation of two new acceptor molecules (BTPT-OD and BTPT-4F-OD), which have one of the simplest fused structures among the Y series of NFAs, along with the mediumenergy bandgap (1.85 eV–1.94 eV) and strong absorption in the visible and near-IR spectral range (700–950 nm). The novel NFAs have high thermal stability, good solubility combined with a high degree of crystallinity, and deep-lying levels of the lowest unoccupied molecular orbital (up to 3.94 eV). The BTPT-OD with indan-1-one-3-dicyanvinyl terminal acceptor group is superior to its counterpart BTPT-4F-OD with 5,6-difluorindan-1-one-3-dicyanvinyl group both in the number ofsynthetic steps and in the photovoltaic performance in OSCs. PM6:BTPT-OD systems exhibit superior photovoltaic performance due to the higher charge mobility and degree of photoresponsiveness, faster carrier extraction, and longer carrier lifetime. As a result, BTPT-OD has almost two times higher photovoltaic performance with PM6 as a donor material due to the higher JSC and FF than BTPT-4F-OD systems. The results obtained indicate that further development of OSCs can be well achieved through a rational molecular design.The work on the synthesis and characterization of BTPT-OD and BTPT-4F-OD was financiallysupported by the Russian Science Foundation (21-43-00051). The work on OSCs was financiallysupported by the National Natural Science Foundation of China (NSFC) (Grant No. 52061135206).The NMR spectra were recorded using the equipment of the Collaborative Access Center ”Center forPolymer Research” of Enikolopov Institute of Synthetic Polymeric Materials of the Russian Academy of Sciences under financial support from the Ministry of Science and Higher Education of the Russian Federation (topic FFSM-2021-0005).
