A new medium-bandgap fused-[1]benzothieno[3,2-b][1]benzo-thiophene (BTBT) nonfullerene acceptor for organic solar cells with high open-circuit voltage

Wang, YC (Wang, Yunchuang)^{[ 1 ]} ; Chang, MJ (Chang, Meijia)^{[ 2,3,4 ]} ; Ke, X (Ke, Xin)^{[ 2,3 ]} ; Wan, XJ (Wan, Xiangjian)^{[ 2,3 ]} ; Yang, GC (Yang, Guangcheng)^{[ 1 ]}

POLYMER, 2019, 185 文献号: 121976

DOI: 10.1016/j.polymer.2019.121976

摘要

A new nonfullerene small molecule acceptor, namely DBTIC, based on an octocyclic thieno[3,2-b]thienodi (indenothiophene) unit using [1]benzothieno[3,2-b][1]-benzothiophene as the core unit, was developed. Despite the medium-bandgap of DBTIC (1.71 eV), a power conversion efficiency of 8.64% can be delivered by the solar cells combining DBTIC and a wide-bandgap polymer donor J52. The high open-circuit voltage (V-oc) of 0.94 V is also rare for J52 based devices owing to the high-lying lowest unoccupied molecular orbital level of DBTIC. Moreover, using J71 with lower highest occupied molecular orbital level as polymer donor, a higher V-oc up to 1.05 V can be achieved.