石墨烯纳米带整流器件电子输运性质研究

Study of electronic transport properties in rectifying devicebased on graphene nanoribbons

运用密度泛函理论和非平衡格林函数结合的方法,研究中心散射区长度对右电极中心N掺杂的扶手椅型石墨烯纳米带电子输运特性的影响。研究表明:在正向偏压下,不同中心散射区长度的扶手椅型石墨烯纳米带电流随着电压的增加而增大;而在负向偏压下,随着中心散射区长度的增加,偏压窗内的透射系数逐渐减小,电流不随电压的变化而变化,电流值接近为零,器件呈现出明显的整流特性。所以,在一定长度范围内,随着中心散射区长度的增加,器件的整流特性逐渐增强。出现该现象的原因可能是负向偏压下偏压窗内没有透射峰引起的,该研究结果对未来石墨烯整流器件的设计具有重要的意义。

By using density functional theory in combination with non-equilibrium Green’s function method to study the effect of central scattering region length on the electron transport properties of N-doped armchair graphene nanoribbons in the center of the right electrode.It is found that the current of armchair graphene nanoribbons with different central scattering region length increases with the increase of voltage under forward bias voltage;while under negative bias voltage,with the increase of central scattering area length,the transmission coefficient in the bias window decreases gradually,the current does not change with the change of voltage,the current value is close to zero,and the device shows obvious rectification characteristics.The result shows that within a certain length range,the rectifying characteristics of the device increases with the increase of scattering length.The reason for this phenomenon may be that there is no transmission peak in the energy range under negative bias voltage.It is important for the design of future graphene rectification devices.