Electronic conductance and thermopower of single-molecule junctions of oligo(phenyleneethynylene) derivatives
Electronic conductance and thermopower of single-molecule junctions of oligo(phenyleneethynylene) derivatives
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DOI：
10.1039/d0nr04413j
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发表时间：
2020-09-28
期刊：
影响因子：
6.7
通讯作者：
Bryce, Martin R.
中科院分区：
文献类型：
--
作者：
Dekkiche, Herve;Gemma, Andrea;Bryce, Martin R.
我们报告了三种新型低聚苯乙炔基 (OPE3) 衍生物的合成和单分子传输特性，这些衍生物具有末端二氢苯并[b]噻吩 (DHBT) 锚定基团和各种核心取代基（亚苯基、2,5-二甲氧基亚苯基和 9,10-蒽基）。它们的电子电导和塞贝克系数是通过金电极之间基于扫描隧道显微镜的断裂结（STM-BJ）实验确定的。使用基于 DFT 的计算方法对分子连接的传输特性进行了建模，该方法揭示了 DHBT 锚的硫原子与电极的特异性结合。实验确定的塞贝克系数在该系列中的-7.9和-11.4μV K(-1)之间变化，并且负号与通过分子的LUMO能级的电荷传输一致。
We report the synthesis and the single-molecule transport properties of three new oligo(phenyleneethynylene) (OPE3) derivatives possessing terminal dihydrobenzo[b]thiophene (DHBT) anchoring groups and various core substituents (phenylene, 2,5-dimethoxyphenylene and 9,10-anthracenyl). Their electronic conductance and their Seebeck coefficient have been determined using scanning tunneling microscopy-based break junction (STM-BJ) experiments between gold electrodes. The transport properties of the molecular junctions have been modelled using DFT-based computational methods which reveal a specific binding of the sulfur atom of the DHBT anchor to the electrodes. The experimentally determined Seebeck coefficient varies between -7.9 and -11.4 mu V K(-1)in the series and the negative sign is consistent with charge transport through the LUMO levels of the molecules.