运用第一性原理的密度泛函理论,结合非平衡格林函数,研究了边缘裁剪对Zigzag石墨纳米带(ZGNRs)的电子结构与输运性能的影响。计算结果表明,对Zigzag石墨纳米带边缘的裁剪显著影响了体系的电子输运性能。其中,边缘裁剪使得金属型石墨纳米带的能隙打开,而且随着结构中的Zigzag边缘长度减少,能隙逐渐增大,使得体系由金属型向半导体型转变;同时,边缘裁剪使Zigzag金属型石墨烯纳米带的输运性能降低,电流-电压呈非线性变化,尤其对于M3体系而言,边缘的裁剪使体系表现出很好的开关特性。
By using nonequilibrium Green's functions in combination with the density-functional theory,electronic transport properties of the edge cutting zigzag graphene nanoribbons were investigated.The models with both zigzag and armchair edge can be got by edge cutting.The edge cutting graphene nanoribbons possess typical semiconductor properties due to the generated band gap.Furthermore,the model with shorter zigzag edge have wider band gap.The current of three models increases rapidly when the bias voltage reaches the threshold voltage,which indicate its broad potential applications in sensors and switching devices.In addition,the behavior is best in M3 structures in a appropriate bias voltage range.Hence,the results demonstrate that edge cutting changed the transport properties of graphene nanoribbons.