电极距离对4,4′-联苯二硫酚分子器件非弹性电子隧穿谱的影响

Influence of the Distance of Electrodes on the Inelastic Electron Tunneling Spectra of 4,4′-biphenyldithiol Molecular Device

基于杂化密度泛函理论和格林函数方法,计算了4,4′-联苯二硫酚分子器件的非弹性电子隧穿谱,并研究了电极距离对该非弹性电子隧穿谱的影响.计算结果表明,非弹性电子隧穿谱随电极距离的改变呈明显不同的特征,从而表明了分子的非弹性电子隧穿谱技术能够灵敏地反映出分子器件的微观结构.研究结果显示,垂直于电极表面的振动模式对非弹性电子隧穿谱具有较大的贡献.

A first-principle computational method based on the hybrid density functional theory was used to calculate the inelastic electron tunneling spectra （IETS） of 4,4＇-biphenyldithiol molecular electronic devices. The influence of distance of electrodes on the IETS was investigated. The molecular geometric structures and the IETS were studied for different distances between two gold electrodes. When the distance of the electrodes changed, the numerical results showed that the IETS had a sensitive variation, which demonstrated that the IETS was a good method to explore microstructure of molecular devices. The vibrational modes with direction perpendicular to the electrode surface gave a great contribution to the IETS.