Dielectric and electrical properties of reduced graphene oxide paper after electron irradiation

Abstract

We present the results of a study of the dielectric and electrical properties of macroscopic reduced graphene oxide paper (RGOP) before and after 1 MeV electron irradiation with a low dose of 1⋅1016 cm−2. It was found that the Coulomb interaction affects the transport of charge carriers and causes their strong localization within graphene domains. The conductivity of the RGOP can be described by the charge carrier tunneling through a disordered graphene quantum dot array. It was shown that charge carrier localization length decreases from 5–8 nm to 1–2 nm after electron irradiation. Structural and electrical studies revealed that the irradiated sample demonstrates electrical conductivity higher than the initial one, despite the lower sp2-carbon fraction, the lower localization length, unchanged average size of graphene domains, and the higher defect states and functional groups content. The improvement in conductivity is also accompanied by an increase in the dielectric permittivity ɛ from 5 for the initial RGOP to 35 after electron irradiation. The data obtained indicate that disordered regions can affect the electrical properties of reduced graphene oxide.