文献类型： 外文期刊

作者： An, Lili ² ; Tong, Junfeng ¹ ; Yang, Chunyan ¹ ; Zhao, Xu ³ ; Wang, Xunchang ⁴ ; Xia, Yangjun ¹ ;

作者机构： 1.Lanzhou Jiaotong Univ, Sch Mat Sci & Engn, Lanzhou 730070, Gansu, Peoples R China

2.Northwest Minzu Univ, Sch Chem Engn, Key Lab Util Environm Friendly Composite Mat & Bi, Lanzhou, Gansu, Peoples R China

3.Gansu Acad Agr Sci, Inst Soil Fertilizer & Water Saving Agr, Lanzhou, Gansu, Peoples R China

4.Chinese Acad Sci, Qingdao Inst Bioenergy & Bioproc Technol, CAS Key Lab Biobased Mat, Qingdao, Shandong, Peoples R China

关键词： naphtho[1,2-c:5,6-c ']bis[1,2,5]thiadiazole; indacenodithieno[3,2-b]thiophene; alkyl side chain; aggregation; photostability

期刊名称：POLYMER INTERNATIONAL （ 影响因子：2.99； 五年影响因子：2.74 ）

ISSN： 0959-8103

年卷期： 2020 年 69 卷 2 期

页码：

收录情况： SCI

摘要： Three donor-pi-acceptor (D-pi-A) type alternating conjugated polymers, namely PIDTT-DTNT-C16, PIDTT-DTNT-HD and PIDTT-DTNT-OD bearing the same backbone of indacenodithieno[3,2-b]thiophene (IDTT) as the D unit and naphtho[1,2-c:5,6-c ']bis[1,2,5]thiadiazole (NT) as the A moiety but with different flexible side chain (n-hexadecyl (C16), 2-hexyldecyl (HD) and 2-octyldodecyl (OD)) substituted thiophene employed as pi-bridges, were synthesized and characterized. The effects of the side chain on absorption, photostability, energy levels, aggregation, backbone conformation, morphology and photovoltaic properties were systematically investigated. Because moderate D and strong A units were selected to construct the polymer backbone, a medium optical bandgap (ca. 1.66 eV) and low-lying highest occupied molecular orbital energy level (E-HOMO approximate to -5.36 V), thus resulting in a relatively higher open-circuit voltage (V-OC) of 0.80-0.83 V, were achieved. It was found that the side chain gave rise to an insignificant impact on absorption, aggregation and photostability in chlorobenzene solution and energy levels but a non-negligible influence on absorption, photostability and aggregation behavior in the film state. It was found that PIDTT-DTNT-C16 with the densest and most ordered packing structure exhibited the best photostability. Inverted bulk heterojunction polymer solar cells based on PIDTT-DTNT-HD:PC61BM ([6,6]-phenyl-C-61-butyric acid methyl ester) showed at least a 1.5-fold increase in power conversion efficiency, chiefly originating from its slightly improved absorption, more balanced mu(h)/mu(e) ratio and favorable morphology of the active layer as a result of incorporating branched HD side chains into the IDTT-alt-DTNT backbone. (c) 2019 Society of Chemical Industry