Abstract
The current investigation describes the first-ever reported and enlightening observation of transitional ordering in thermally reduced graphene Oxide (trGO). The paper reports reduction of trGO film at high voltage and investigates the variation of trGO sheet resistance with thickness and the dependence of resistivity and bandgap on carbon to oxygen (C/O) ratio. An initial exponential diminution in sheet resistance, from 19.42 k omega/sq. to 0.54 k omega/sq., has been observed on increasing the trGO film thickness from 0.5 mu m to 10 mu m, followed by a stable constant resistance value attained at 5 mu m. A decrease in sheet resistance, from 19.42 k omega/sq to 4.3 k omega/sq, is observed when 0.5 mu m thick trGO film is subjected to -20 V voltage for 22s. The variation in sheet resistance corresponding to low values of C/O ratio has been critically investigated and as the C/O ratio is further increased it is observed to attain stability. The estimated resistivity and bandgap are found to decrease with increasing C/O ratio. A transitional ordering in sheet resistance has been observed as the thickness of rGO-films crosses 0.05 mu m.