Abstract:
Environmental control of single-molecule junction evolution and conductance was demonstrated for expanded pyridinium molecules by scanning tunneling microscopy break junction method and interpreted by quantum transport calculations including solvent molecules explicitly. Fully extended and highly conducting molecular junctions prevail in water environment as opposed to short and less conducting junctions formed in non-solvating mesitylene. A theoretical approach correctly models single-molecule conductance values considering the experimental junction length. Most pronounced difference in the molecular junction formation and conductance was identified for a molecule with the highest stabilization energy on the gold substrate confirming the importance of molecule-electrode interactions. Presented concept of tuning conductance through molecule-electrode interactions in the solvent-driven junctions can be used in the development of new molecular electronic devices.
摘要:
通过扫描隧道显微镜断裂结法证明了膨胀吡啶鎓分子的单分子结演化和电导的环境控制,并通过包括溶剂分子在内的量子传输计算进行了解释。与在非溶剂化均三甲苯中形成的短且导电较少的结相反,完全延伸且高导电的分子结在水环境中占主导地位。考虑到实验结长度,理论方法可以正确地模拟单分子电导值。对于金基板上具有最高稳定能的分子,确定了分子结形成和电导的最明显差异,这证实了分子-电极相互作用的重要性。提出的通过溶剂驱动结中的分子-电极相互作用调节电导的概念可用于开发新的分子电子器件。