Prolonged exciton lifetime via conjugation-length engineering in M-series acceptors for 19.39% efficiency polymer solar cells. - Shen, Wenxiong; Xiong, Xiaoying; Cai, Dongdong; Liu, Li; Lin, Junlu; Wan, Shuo; Wang, Jin-Yun; Li, Yi; Ma, Yunlong; Fu, Huiting (National Science Review, 2026)