Metal to insulator transition in conducting polyaniline/graphene oxide composites

Abstract

Broadband dielectric spectroscopy measurements of polyaniline/graphene oxide composites were conducted for an as-prepared and a thermally annealed specimen, respectively, from 15 K to room temperature. The electrical conductivity values of the annealed composite display a very modest rise denoting the important contributions of the graphene oxide component to achieving electrical stability of the polymer. Patterns of the dc conductivity as a function of temperature also reveal a metal to insulator transition at around 75 K. The transition is dominated by two key factors: temperature and annealing process. Metal-like and insulating features are subsequently detected, as well, and accordingly described to provide a qualitative inspection of the charge transfer mechanisms involved.