Thermally stable high performance non-fullerene polymer solar cells with low energy loss by using ladder-type small molecule acceptors

• DOI: 10.1016/j.orgel.2017.02.008
• Publication Date: 2017-02-09T20:33:23Z
• Authors: Qing-Ya Li; Jingyang Xiao; Lu-Ming Tang; Hua-Chun Wang; Ziming Chen; Zhiyong Yang; Hin-Lap Yip; Yun-Xiang Xu
• Keywords: Thermal Stability; Acceptor

Abstract Two ladder-type small molecule acceptors IDT-BT-R and IDT-BT-R-CN are utilized in non-fullerene polymer solar cells by pairing with PTB7-Th as donor polymer, in which PTB7-Th:IDT-BT-R solar cells achieve high performance up to 8.3% with high voltage of 1.02 V and low energy loss of 0.59 eV. Thermal annealing triggered local rearrangement of ladder-type molecules in n-type phases of bulk heterojunction films, increased their absorption abilities and electron transport properties, therefore resulting in improved short-circuit current densities (Jscs) and fill factors (FFs), in contrast to fullerene-based solar cells which suffered from extensive aggregation of fullerenes upon annealing. The outstanding thermal stability, high performance and low energy loss demonstrated here show great potential of non-fullerene polymer solar cells.