Effect of cobalt-60 gamma irradiation on graphene: Raman and field emission investigations

Electrophoretically deposited graphene (HG) on silicon is irradiated using a cobalt-60 gamma radiation source with the radiation dose up to 22.7kGy. The effect of gamma irradiation on the field emission current noise behavior of HG is investigated. The power spectra of pristine and irradiated HG exhibit 1/f(alpha) type of noise, with alpha similar to 0.8. The magnitude of noise power is observed to increase with the radiation dose. The variations in the turn on field and noise power in the emission current are attributed to the structural modifications of HG, as revealed from the field emission scanning electron microscopic and Raman spectroscopic studies.