硅纳米结点电子输运性质的计算  

Electron Transport in Silicon Nanoscale Junctions

作　　者：柳福提[1,2] 程艳[2] 羊富彬[2] 程晓洪[1] 陈向荣[2] 

机构地区：[1]宜宾学院物理与电子工程学院,四川宜宾644000 [2]四川大学物理科学与技术学院,四川成都610065

出　　处：《计算物理》2013年第6期943-948,共6页Chinese Journal of Computational Physics

基　　金：国家自然科学基金(11174214;11204192);四川省教育厅科研项目(13ZB0207)资助项目

摘　　要：运用第一性原理密度泛函理论结合非平衡格林函数方法,对3个Si原子构成的直线链耦合在Au(100)面形成的三明治结构的纳米结点的电子输运进行计算.结果得到结点电导随距离的变化,当d z=1.584 nm时,结合能最小,结构最稳定,此时Si-Si键长为0.216 nm,Si-Au键长为0.227 nm,电导为0.729 G0(G0=2e2/h),其电子传输通道主要由Si原子的p x、p y轨道电子构成;随着外电压的增大,结点的电导减小,而其I-V曲线表现出线性特征.Electron transport in a linear atomic chain composed of 3 silicon atoms and sandwiched between gold electrodes is investigated with combination of density functional theory and non-equilibrium Green＇s function method. Relationship of conductance with distance is calculated. It shows that： At a distance of 1. 584 nm, binding energy of junctions is minimum, structure is the most stable, Si-Si bond length is 0. 216 nm, Si-Au bond length is 0. 227 nm, conductance is 0. 729 Go （Go = 2e2/h）, electron transport channels mainly consist of p,, py orbital electrons of Si atoms. With increase of voltage conductance decreases and I-V curve of nanoscale junctions at equilibrium position shows linear feature.

关 键 词：密度泛函理论 非平衡格林函数 硅纳米结点 电子输运 

分 类 号：O488[理学—固体物理] O469[理学—物理]