O/N替代掺杂对zigzag型硼氮窄纳米带能带及输运特性的影响

用第一性原理非平衡格林函数方法研究了O原子掺杂zigzag型硼氮窄纳米带(z-BNNNRs)的能带结构和电子输运特性.研究结果表明:O原子对N原子的替代掺杂使z-BNNNRs的能带结构出现明显变化,体系由半导体转变为金属;O掺杂明显地改变了z-BNNNRs体系的导电性能,在一定的偏压范围内产生明显的负微分电阻(NDR)现象,边缘掺杂比中间掺杂产生更大的负微分电导,进一步的输运性质计算给出的透射谱也印证了这一点.随着掺杂浓度的增加,负微分电导的极值也随之增大.

Effect of O/N Substitutive Doping on the Band Structure and Transport Properties of the zigzag Boron Nitride Narrow-Nanoribbons

By performing first-principles calculations and non-equilibrium Green′s function,the energy band structure,transmission spectrum and current-voltage characteristics of the O-doping zigzag boron nitride narrow-nanoribbons(z-BNNNRs)were investigated.The calculation results show that O-doping remarkably changes the z-BNNNRs energy band structure and transform the material from a semiconductor to a metal.It is also demonstrated that the system exhibits an obvious negative differential resistance(NDR)characteristic.Further investigations revealed that the position and concentration of O-doping also affected the NDR behavior over a certain range of bias.The negative differential conductance(NDC)for edge-doping is greater than that for middle-doping and the maximum of the NDC increases with an increase of the concentration of O-doping.This special electronic transport property of O-doping z-BNNNRs makes it more suitable as a candidate for molecular devices.