Significant Improvement of Semiconducting Performance of the Diketopyrrolopyrrole-Quaterthiophene Conjugated Polymer through Side-Chain Engineering via Hydrogen-Bonding
Significant Improvement of Semiconducting Performance of the Diketopyrrolopyrrole-Quaterthiophene Conjugated Polymer through Side-Chain Engineering via Hydrogen-Bonding
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DOI：
10.1021/jacs.5b09737
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发表时间：
2016-01-13
影响因子：
15
通讯作者：
Zhang, Deqing
中科院分区：
文献类型：
--
作者：
Yao, Jingjing;Yu, Chenmin;Zhang, Deqing
制备并研究了三种二酮吡咯并吡咯（DPP）-四噻吩共轭聚合物pDPP4T-1、pDPP4T-2和pDPP4T-3，其中含脲烷基链与支化烷基链的摩尔比分别为1:30、1:20和1:10。与烷基侧链不含脲基的pDPP4T以及同时含有直链和支链烷基链的pDPP4T-A、pDPP4T-B和pDPP4T-C相比，pDPP4T-1、pDPP4T-2和pDPP4T-3的薄膜表现出更高的空穴迁移率；薄膜迁移率按 pDPP4T-1 < pDPP4T-2 < pDPP4T-3 的顺序增加，pDPP4T-3 薄膜在 100 ℃ 热退火后空穴迁移率可达 13.1 cm2 V-1 s-1。烷基侧链中脲基的引入对 DPP-四噻吩共轭聚合物的光伏性能也产生了有趣的影响。与PC71BM混合。 pDPP4T-1:PC71BM、pDPP4T-2:PC71BM 和 pDPP4T-3:PC71BM 的混合薄膜表现出比 pDPP4T:PC71BM、pDPP4T-A:PC71BM、pDPP4T-B:PC71BM 和 pDPP4T-C:PC71BM 更高的功率转换效率 (PCE)。 pDPP4T-1:PC71BM的PCE达到6.8%。使用 AFM、GIXRD 和 STEM 对 pDPP4T-1、pDPP4T-2 和 pDPP4T-3 薄膜以及相应的 PC71BM 薄膜进行了表征。结果表明，pDPP4T-1、pDPP4T-2和pDPP4T-3薄膜的烷基链层状堆积顺序明显增强；热退火后，pDPP4T-2 和 pDPP4T-3 出现轻微的链间 p-p 堆积。 pDPP4T-1、pDPP4T-2 和 pDPP4T-3 与 PC71BM 的共混物表现出更明显的微相分离。这些观察结果表明，脲基团的存在可能进一步促进这些共轭聚合物组装成纳米纤维和 PC71BM 的有序聚集。
Three diketopyrrolopyrrole (DPP)-quaterthiophene conjugated polymers, pDPP4T-1, pDPP4T-2, and pDPP4T-3, in which the molar ratios of the urea-containing alkyl chains vs branching alkyl chains are 1:30, 1:20, and 1:10, respectively, were prepared and investigated. In comparison with pDPP4T without urea groups in the alkyl side chains and pDPP4T-A, pDPP4T-B, and pDPP4T-C containing both linear and branched alkyl chains, thin films of pDPP4T-1, pDPP4T-2, and pDPP4T-3 exhibit higher hole mobilities; thin-film mobility increases in the order pDPP4T-1 < pDPP4T-2 < pDPP4T-3, and hole mobility of a thin film of pDPP4T-3 can reach 13.1 cm2 V-1 s-1 after thermal annealing at just 100 degrees C. The incorporation of urea groups in the alkyl side chains also has an interesting effect on the photovoltaic performances of DPP-quaterthiophene conjugated polymers after blending with PC71BM. Blended thin films of pDPP4T-1:PC71BM, pDPP4T-2:PC71BM, and pDPP4T-3:PC71BM exhibit higher power conversion efficiencies (PCEs) than pDPP4T:PC71BM, pDPP4T-A:PC71BM, pDPP4T-B:PC71BM, and pDPP4T-C:PC71BM. The PCE of pDPP4T-1:PC71BM reaches 6.8%. Thin films of pDPP4T-1, pDPP4T-2, and pDPP4T-3 and corresponding thin films with PC71BM were characterized with AFM, GIXRD, and STEM. The results reveal that the lamellar packing order of the alkyl chains is obviously enhanced for thin films of pDPP4T-1, pDPP4T-2, and pDPP4T-3; after thermal annealing, slight inter-chain p-p stacking emerges for pDPP4T-2 and pDPP4T-3. Blends of pDPP4T-1, pDPP4T-2, and pDPP4T-3 with PC71BM show a more pronounced micro-phase separation. These observations suggest that the presence of urea groups may further facilitate the assemblies of these conjugated polymers into nanofibers and ordered aggregation of PC71BM.