Single-molecule rectifiers based on voltage-dependent deformation of molecular orbitals in carbazole oligomers
Single-molecule rectifiers based on voltage-dependent deformation of molecular orbitals in carbazole oligomers
复制标题
基于咔唑低聚物中分子轨道电压依赖性变形的单分子整流器
DOI：
10.1039/c8nr06049e
复制
发表时间：
2018
期刊：
影响因子：
6.7
通讯作者：
Hirokazu Tada
中科院分区：
文献类型：
--
作者：
Ryo Yamada;Ken Albrecht;Tatsuhiko Ohto;Keigo Minode;Kimihisa Yamamoto;Hirokazu Tada
单分子结的电流-电压特性由分子轨道相对于电极的费米能级的能级对准和分子与电极之间的界面处的电子结构的杂化两者来控制。虽然有很多研究调前者，只有少数作品旨在控制后者。在本研究中，我们证明了基于咔唑低聚物的分子结显示出电流整流行为，由于不对称-对称控制的分子和电极之间的电子杂化在两端。咔唑低聚物最初表现出不对称的分子轨道，因此，由于电偶极矩与电极的电子杂化。当电极间外加电场使分子轨道对称时，可实现对称电子杂化。这是一种控制单分子结中电荷输运的新方法。
Current–voltage characteristics of single molecule junctions are governed both by the energy level alignment of molecular orbitals with respect to the Fermi level of the electrodes and by the hybridization of electronic structures at the interface between the molecule and the electrodes. While there have been many studies on tuning the former, only a few works intended to control the latter. In the present study, we demonstrate that molecular junctions based on carbazole oligomers showed a current rectification behavior due to asymmetric–symmetric control of electronic hybridization between the molecule and electrodes at the both terminals. The carbazole oligomers originally showed an asymmetric molecular orbital and, hence, electronic hybridization with the electrodes because of the electric dipole moment. Symmetric electronic hybridization was achieved when the applied electric field between electrodes deformed molecular orbital to be symmetric. This is a novel way to control charge transport in single-molecule junctions.