Effect of Mechanical Strain on Electric Conductance of Molecular Junctions
Effect of Mechanical Strain on Electric Conductance of Molecular Junctions
复制标题
机械应变对分子结电导的影响
DOI：
10.1021/acs.jpcc.5b04386
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
M. Kiguchi
中科院分区：
文献类型：
--
作者：
J. Inatomi;S. Fujii;S. M. Gonzalez;H. Masai;Y. Tsuji;J. Terao;M. Kiguchi
利用基于断裂结的扫描隧道显微镜方法研究了单分子结的机电特性。由具有和不具有配位键合的π-共轭主链组成的两种类型的分子结（即，在两个Au电极之间制备了Co（（4-苯胺）-三联吡啶）2配合物和低聚（苯乙炔）衍生物。电子输运测量显示ca的分子电导。10-4G0（G0= 2e2/h）。然后，我们评估的电子输运性质的两种类型的分子结的机械应变下，在其压缩-拉伸周期。我们发现，所有的共价体系的oligo（苯乙炔）衍生物的显着的不对称机电响应，而与协调键合的Co配合物表现出对称调制的电子输运性质的压缩-拉伸周期的分子结。非对称和对称的机电行为可以分别归因于π共轭骨架中的刚性共价键和金属中心处的柔性配位键。这项研究表明，在机械刺激下的分子电导的潜在可调性。
Electromechanical properties of single molecular junctions are investigated using scanning tunneling microscopy based break junction method. Two types of molecular junctions consisting of π-conjugated backbones with and without coordinative bonding (i.e., Co((4-aniline)-terpyridine)2complex and oligo(phenylene-ethynylene) derivative) are prepared between two Au electrodes. Electronic transport measurements revealed molecular conductance of ca. 10–4G0(G0= 2e2/h) for both of the molecular junctions. Then we assessed the electronic transport properties of the two types of molecular junctions under mechanical strain in their compression–elongation cycle. We found significant asymmetric electromechanical response for all covalent systems of the oligo(phenylene-ethynylene) derivative, while the Co complex with the coordinative bonding exhibits symmetric modulation of the electronic transport property in the compression–elongation cycle of the molecular junctions. The asymmetric and symmetric electromechanical behavior can be, respectively, ascribed to rigid covalent bonding in the π-conjugated backbone and flexible coordinative bonding at the metal center. This study demonstrates potential tunability of the molecular conductance under mechanical stimulus.