Annealing effect on the optoelectronic properties of graphene oxide thin films

Graphene oxide (GO) thin films were prepared by solution-casting of non-reduced suspension on glass substrates at ambient conditions. Films were rendered to conductive both with hydrazine treatment and annealing and the results were compared. Annealed films treated without hydrazine revealed superiority over the others. Surface morphology of these films showed very smooth film texture as seen by scanning electron microscope and atomic force microscope. Different optical and electrical parameters were analyzed. Band gap enhanced from 1.25 to 2.4 eV as the solution concentration was decreased where the transmittance increased. This work, in particular represents a straight forward approach compared to other studies to achieve device-quality GO thin films and the findings are important for various optoelectronic applications.