Thermal and Electrical Transport in Partly-Reduced Graphene Oxide Films: The Effect of Low Temperature and Structure Domain Size

Understanding the effect of grain size on the overall electrical and thermal transport properties of PRGO films on a large scale is not only fundamental but also technologically important in order to tune their properties for wide applications. In this work, by adjusting the annealing temperature, we control the density of the oxygen containing functional groups and thus the structural domain size of PRGO film. The annealing effect on the temperature dependency of thermal and electrical transport is studied. In addition, the linear relationship between thermal diffusivity and electrical conductivity is confirmed from 320 K to 10 K. The temperature dependent thermal diffusivity of the amorphous region in PRGO is reported. In the last, based on the residual thermal reffusivity at 0 K limit, the structure defects induced phonon mean free path against the annealing temperature is obtained, and compared with the cluster size calculated from XRD, TEM and Raman. A linear relationship among the structure domain size, thermal diffusivity, and electrical conductivity is further revealed, which demonstrates the strong effect of structure domain size on the thermal and electrical transport of PRGO.