摘要
基于密度泛函理论,运用非平衡格林函数的方法,对B直线原子链、N直线原子链、Si直线原子链耦合石墨烯纳米带构成分子器件的电子输运特性进行了第一性原理模拟,计算得到3种不同构型分子器件的平衡电导,分别为1.16 G0,0.79 G0,1.16 G0.电荷布局计算结果表明,原子链耦合石墨烯改变了原子链原子的局域态密度,为电子的传输提供了更多的隧穿模式.在0~1.2 V时,对于graphene+5B,graphene+5Si分子器件的电流随着电压的增大而增大,其I-V关系近似为线性关系,表现出金属导电特性;而对于graphene+5N分别在0~0.7 V,0.9~1.2 V时,I-V关系近似为线性,但在0.7~0.8 V时却存在负微分电阻现象.
Electron transport properties of boron linear atomic chains, nitrogen linear atomic chains, silicon linear atomic chains, coupling with graphene nanoribbons, are simulated with a combination of density functional theory and non-equilibrium green＇s function method from first principles. The equilibrium conductance of three kinds of molecular devices is 1.16 Go, 0.79 Go, 1.16 G0, respectively. The results of calculation on Mulliken population show that atomic chains coupling graphene nanoribbons change the local density of states of the atoms in the chain, and it provides more tunneling mode for electron transport. In the voltage range of 0 ～1.2 V, the current increases with the voltage increasing for graphene＋SB and graphene＋SSi molecular devices, the relationship of I-V is approximately to linear. That shows these two kinds of molecular devices have metal conductive properties.In the voltage range of 0 ～0.7 V and 0.9～ 1.2 V, the relationship of I- V approximate to linear, but in the range of 0.7 ～ 0.8 V, there is a negative differential resistance phenomenon for graphene＋5N molecular devices.
作者
张淑华
程晓洪
柳福提
ZHANG Shuhua CHENG Xiaohong LIU Futi(School of Chemistry and Engineeing, College of Yibin, Sichuan Yibin 644000, China Sohool Physics and Electron, College of Yibin, Sichuan Yibin 644000, China)
出处
《河北师范大学学报（自然科学版）》
CAS
2017年第1期32-38,共7页
Journal of Hebei Normal University：Natural Science
基金
四川省高等学校重点实验室基金(JSWL2015KF02)
宜宾学院科研基金(2015QD14)
关键词
原子链
石墨烯
电子输运
平衡电导
atomic chains
graphene
electron transport
equilibrium conductance
