Xia Benzheng, Lu Kun, Zhao Yifan, Zhang Jianqi, Yuan Liu, Zhu Lingyun, Yi Yuanping, Wei Zhixiang
National Center for Nanoscience and Technology Beijing 100190 P. R. China.
Institute of Chemistry Chinese Academy of Sciences Beijing 100190 P. R. China.
Adv Sci (Weinh). 2015 Mar 13;2(4):1500021. doi: 10.1002/advs.201500021. eCollection 2015 Apr.
A linked-acceptor type conjugated polymer is designed and sythesized based on 4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-:4,5-]dithiophene (BDTT) and linked-thieno[3,4-]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 () 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 with values 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-C-butyric acid methyl ester may be a promising candidate for the front cell in tandem polymer solar cells.
基于4,8-双(5-(2-乙基己基)噻吩-2-基)苯并[1,2-b:4,5-b']二噻吩(BDTT)和连接噻吩并[3,4-c]吡咯-4,6-二酮(LTPD)设计并合成了一种连接受体型共轭聚合物。该聚合物使用烷基取代噻吩作为桥连基团。PBDTT-LTPD在一个重复单元中包含两个TPD单元，这可以提高聚合物主链中的受体密度并降低最高占据分子轨道(HOMO)能级。相比之下，噻吩桥连基团中的可变烷基取代确保了聚合物性能的精细调控。基于PBDTT-LTPD的太阳能电池显示出超过1 V的开路电压(Voc)，并获得了7.59%的最大功率转换效率(PCE)。对于Voc高达1 V的传统单结本体异质结太阳能电池，该PCE值是最高的。鉴于PBDTT-LTPD表现出较低的HOMO能级和与聚(3-己基噻吩)相当的带隙，PBDTT-LTPD/苯基-C-丁酸甲酯可能是串联聚合物太阳能电池前电池的一个有前途的候选材料。
