摘要
以C-Si-C-Si直线原子链与Au(100)-3×3电极耦合所构成的纳米结点为研究对象,用密度泛函理论结合非平衡格林函数的方法,对结点的电子输运进行了理论模拟.计算结果得到:当2电极距离为1.686 nm时,纳米结点体系总能量最低,结构最稳定,C-Si平均键长为0.166 nm,此时结点的透射系数为0.627,平衡电导为0.627 G_0,电子传输通道主要由碳、硅原子的p电子轨道形成的π键所构成;在电压为0～1.0 V时,纳米结点稳定结构的电导随着外偏压的增大而减小.
Electronic transport properties of the C-Si-C-Si atomic chain sandwiched between Au(100)-3×3 electrodes is investigated from first principle.In the range of 1.566 nm to 2.126 nm,as the junctions stretching,we optimize the structure of the geometry of nanoscale junctions in different distances,obtain that when dz=1.686 nm,the total energy is the lowest,the geometry structure is most stable,the average bond length of C-Si is 0.166 nm.We calculate the transmission spectra of the nanoscale junctions at the equilibrium position,and obtain the equilibrium conductance is 0.627 G0.We calculate the projected density of states of atomic chain,conclude that the electronic transmission channel is mainly composed of p orbits electrons of carbon and silicon atoms.We calculate the conductance of the nanoscale junctions at the equilibrium position under different external voltage up to 1.0 V,and obtain the conductance decreases gradually with the external bias increases.
作者
张淑华
柳福提
ZHANG Shuhua;LIU Futi(College of Chemistry and Chemical Engineering,Yibin University,Sichuan Yibin 644000,China;College of Physics and Electronic Engineering,Yibin University,Sichuan Yibin 644000,China)
出处
《河北师范大学学报（自然科学版）》
CAS
2019年第2期129-133,共5页
Journal of Hebei Normal University：Natural Science
基金
宜宾学院重点科研项目(2015QD14)
关键词
碳硅原子链
电子输运
非平衡格林函数
第一性原理
carbon silicon atomic chain
electronic transport
non-equilibrium green function
first principle
