Ji Wan, Tao Wang, Rui Sun, Xiaohei Wu, Shanshan Wang, Meimei Zhang, Jie Min.Advanced Materials（汪涛、闵杰）.

Abstract：

        The simultaneous improvement of power conversion efficiency (PCE) and thermal stability is a critical scientific challenge in advancing the commercial applications of polymer solar cells. To address this challenge, we successfully designed and synthesized a dumbbell-shaped dimeric acceptor, DT19, and incorporated it as a third component into the PM1:BTP-eC9 system. This ternary strategy demonstrated a synergistic enhancement of the PCE and thermal stability of the host binary system. In particular, the PM1:BTP-eC9:DT19 system maintained a PCE of over 90% even after heating at 120°C for 200 hours. Additionally, the dimer-doping ternary strategy exhibited excellent generality for the other four Y-series systems and outperformed ternary systems containing alloy-like acceptors in terms of thermal stability. It is because DT19, with its hinge-like structure, can form a semi-alloy acceptor with the host acceptor, leading to strong interchain entanglement with the polymer donor, thus overcoming phase separation and excessive aggregation under thermal stress. This new type of dimeric material, which can synergistically enhance the device efficiency and thermal stability of active layers, presents promising application prospects.

        论文链接：https://doi.org/10.1002/adma.202302592