摘要
以s-四嗪作为拉电子结构单元(A),以二氟取代四噻吩衍生物作为推电子结构单元(D),并分别以2-己基癸烷基,2-辛基十二烷基,2-癸基十四烷基作为侧链,设计并合成了三种D-A型聚合物光伏材料P(Tet-T16)、P(Tet-T20)和P(Tet-T24)。研究结果表明,具有最短烷基链的聚合物P(Tet-T16)表现出最弱的分子间π-π堆砌,而具有合适长度烷基侧链(2-辛基十二烷基)的聚合物P(Tet-T20)具有最强的分子间相互作用和最有规律的分子堆砌,这更有利于载流子的传输。因此,基于P(Tet-T20)/PC71BM的聚合物太阳能电池器件表现出最佳光伏性能(PCE=5.10%)。同时,由于三种聚合物的HOMO能级都低于-5.56eV,三种富勒烯PSCs器件的开路电压(Voc)均高于1.00V,其中,基于P(Tet-T24)的PSC表现出1.04V的高Voc值,这是目前报道的以s-四嗪基聚合物作为给体材料的PSCs中的最高Voc值。但过低HOMO能级与高性能非富勒烯受体的HOMO能级不匹配,限制了其在非富勒烯PSCs中的应用。
Three polymer photovoltaic materials of P(Tet-T16),P(Tet-T20)and P(Tet-T24)have been synthesized by using s-tetrazine as A unit and a difluoro-substituted tetrathiophene derivative as D unit with 2-hexyldecylalkyl,2-octyldodecyl and 2-decyltetradecyl as side chains respectively.The results show that P(Tet-T16)with the shortest alkyl chain exhibits the weakest intermolecularπ-πstacking.P(Tet-T20)with an appropriate length of alkyl side chain(2-octyl dodecyl)possesses the strongest intermolecular interaction and the most regular molecular stacking,which is in favour of better carrier transport.Therefore,the PSC based on P(Tet-T20)/PC 71 BM exhibits the best power conversion efficiency(PCE=5.10%).The V oc of the three fullerene PSCs are higher than 1.0 V since the HOMO(highest occupied molecular orbital)levels of three polymers are all lower than-5.56 eV.Among them,the PSC based on P(Tet-T24)exhibits a Voc(open circuit voltage)of 1.04 V,which is the highest Voc in the currently reported PSCs with s-tetrazine-based polymers as donor materials.However,the extremely low HOMO level of the three polymers does not match the HOMO level of the high performance non-fullerene receptor,which limits its application in non-fullerene PSCs.
作者
刘海路
彭栗妮
LIU Hai-lu;PENG Li-ni(Hunan Chemical Vocational Technology College,Zhuzhou 412000,China;Xiangtan University,Xiangtan 411000,China)
出处
《化学研究与应用》
CAS
CSCD
北大核心
2020年第6期971-978,共8页
Chemical Research and Application
基金
湖南省自然科学基金项目(2019JJ70073)资助
湖南省教育厅一般研究项目(18C1355)资助。
关键词
s-四嗪
烷基侧链
聚集态结构
光电转换效率
s-Tetrazine
Alkyl chain
Aggregation structure
Photoelectric transformation efficienc.
作者简介
联系人:刘海路(1987-),男,讲师,博士,主要研究方向:功能高分子材料。E-mail:liuhlpc@163.com。
