Varistor characteristics of a nano-device containing graphene and oxidised graphene: verification by DFT + NEGF

Abstract

Electron transport and quantum conductance through an armchair graphene and its oxidised graphene-containing form were investigated by the density functional theory method and the implementation of the non-equilibrium Green function approach. The computed I − Vb(current as a function of bias voltage) characteristic of the studied systems showed the tunnelling phenomenon in bias and gate voltages considered. Along with the transport properties, electronic properties including density of states were calculated in the studied systems. A close examination of the results showed that the I − Vb curve for graphene behaved like at some bias voltages, while for the oxidised graphene-containing form, its trend was the same as that of a voltage dependent resistor (VDR-VARiable resISTOR), I∝Vβb, at the whole range of the applied bias.