Reaction-time-dependent opto-electrical properties of graphene oxide

The reaction-time-dependent synthesis of graphene oxide (GO) was carried out using a modified Hummer’s method. The drop-casting method was used to coat GO films on a glass substrate. Various techniques, including scanning electron microscopy, X-ray diffraction, UV–Vis spectroscopy (UV–Vis), Fourier transform infrared spectroscopy, and current–voltage characteristics, were performed to obtain the morphological, structural, optical, and electrical properties of GO. Morphological structural observations revealed that more oxygen functional groups were present as the reaction time increased from 24 to 96 h, which was confirmed by the optical properties of GO thin films. The resistivity of the as-deposited films increased from 9.74 × 10⁶ to 26.85 × 10⁶ Ω·cm as the reaction time increased. The optimized reaction time with a resistivity of 12.13 × 10⁶ Ω·cm was 48 h, as demonstrated by morphological and optical data.