title: Linked-Acceptor Type Conjugated Polymer for High Performance Organic Photovoltaics with an Open-Circuit Voltage Exceeding 1 V.
abstract: A linked-acceptor type conjugated polymer is designed and sythesized based on 4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene (BDTT) and linked-thieno[3,4-c]pyrrole-4,6-dione (LTPD). This polymer uses alkyl-substituted thiophene as a bridge. The PBDTT-LTPD includes two TPD units in one repeating unit, which can enhance acceptor density in the polymer backbone and lower the highest occupied molecular orbital (HOMO) level. By contrast, variable alkyl substitutions in the thiophene-bridges ensure the subtle regulation of polymer properties. The solar cells based on PBDTT-LTPD display an open-circuit voltage (Voc) that exceeds 1 V, and a maximum power conversion efficiency (PCE) of 7.59% is obtained. This PCE value is the highest for conventional single-junction bulk heterojunction solar cells withVocvalues of up to 1 V. Given that PBDTT-LTPD exhibits a low HOMO energy level and a band gap equivalent to that of poly(3-hexylthiophene), PBDTT-LTPD/phenyl-C61-butyric acid methyl ester may be a promising candidate for the front cell in tandem polymer solar cells.
authors.affiliation: National Center for Nanoscience and Technology Beijing 100190 P. R. China.
authors.forename: Benzheng
authors.initials: B
authors.lastname: Xia
authors.affiliation: National Center for Nanoscience and Technology Beijing 100190 P. R. China.
authors.forename: Kun
authors.initials: K
authors.lastname: Lu
authors.affiliation: National Center for Nanoscience and Technology Beijing 100190 P. R. China.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: National Center for Nanoscience and Technology Beijing 100190 P. R. China.
authors.forename: Jianqi
authors.initials: J
authors.lastname: Zhang
authors.affiliation: National Center for Nanoscience and Technology Beijing 100190 P. R. China.
authors.forename: Liu
authors.initials: L
authors.lastname: Yuan
authors.affiliation: National Center for Nanoscience and Technology Beijing 100190 P. R. China.
authors.forename: Lingyun
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Institute of Chemistry Chinese Academy of Sciences Beijing 100190 P. R. China.
authors.forename: Yuanping
authors.initials: Y
authors.lastname: Yi
authors.affiliation: National Center for Nanoscience and Technology Beijing 100190 P. R. China.
authors.forename: Zhixiang
authors.initials: Z
authors.lastname: Wei
keywords: high open‐circuit voltage; linked‐acceptor; polymer solar cells