▎ 摘　　要

In this study, we find that thermal treatment in ethanol vapor has a remarkable suppression effect of carrier scattering occurring between reduced graphene oxide (rGO) flakes in large area films. We observe excellent electrical properties such as high carrier mobility (similar to 5 cm(2)/Vs) and low sheet resistance (similar to 40K Omega/square) for the rGO films. From the electrical conductivity analysis of large area rGO films using two-dimensional variable range hopping model and structural analysis using Raman spectra measured from the rGO films, we reveal that the significant effect is caused by the expansion of conjugated pi-electron system in rGO flake due to the efficient restoration of graphitic structure. (C) 2014 AIP Publishing LLC.