To enhance the competitiveness of organic solar cells (OSCs), the light-absorbing molecules must meet several key criteria, including a weak-absorption charge transfer state, high dielectric constant, suitable surface energy, and proper crystallinity. This study presents a rational design of the non-fullerene acceptor o-BTP-eC9, guided by theoretical calculations, exhibiting distinct photoelectric properties compared to BTP-eC9. The o-BTP-eC9-based device demonstrates reduced energy loss and achieves a power conversion efficiency (PCE) of 18.7%. Furthermore, incorporating o-BTP-eC9 into a ternary system (PM6:BTP-C9:o-BTP-eC9) yields a PCE of 19.9% (19.5% certified), along with improved operational stability.

Jiehao Fu, Qianguang Yang, Peihao Huang, Sein Chung, Kilwon Cho, Zhipeng Kan, Heng Liu, Xinhui Lu, Yongwen Lang, Hanjian Lai, Feng He, Patrick W. K. Fong, Shirong Lu, Yang Yang, Zeyun Xiao, Gang Li