锯齿型石墨烯纳米带的电子输运性质

Electron transport properties of zigzag graphene nanoribbons

利用基于紧束缚模型的非平衡格林函数方法研究了锯齿型石墨烯纳米带的电子输运性质。采用Sancho-Rubio算法计算了电极的表面格林函数。分析和讨论了中心器件的宽度不同时能带结构、透射系数、态密度对电子输运的影响。结果表明,透射系数出现了量子化台阶。随着中心器件的宽度的增大,可用的电子能带的数目在增加,透射系数的台阶数也增加。电子能带增加一条时,电子通道多开辟一个,透射系数也增加一个台阶。计算发现在费米能附近的态密度出现了一个很高的峰值。研究结果将为纳米电子器件设计提供参考。

The electron transport properties of zigzag graphene nanoribbons(ZGNRs)are studied via the non-equilibrium Green's function method based on tight binding model.Sancho-Rubio algorithm is used to calculate the surface Green's function of the electrode.The effects of band structure,transmission coefficient and density of states on the electron transport are analyzed and discussed.It is shown that quantization steps appear in the transmission coefficient.With the increase of the width of the central device,the number of available electron bands and the number of steps of the transmission coefficient increase.When one more electron band is added,one more electron channel is opened up and the transmission coefficient increases one step.It is found that there is a high peak of the density of states near the Fermi energy.The research results will provide a reference for the design of nano electronic devices.