RESUMEN
Here, we report the structural and electronic modification induced in chemical vapor deposited graphene by using swift heavy ions (70 MeV Ni6+).Raman spectroscopy was used to quantify the irradiation-induced modification in vibrational properties. The increase in defect density with fluence causes an increase in the intensity ratio of its characteristic Raman D and G band. The increase in defect density also results in a decrease in crystallite size. The changes in the crystal structure are observed from X-rays diffraction measurement. Swift heavy ion irradiation induced defect, modified the surface roughness and surface potential of graphene thin film as measured from atomic force microscopy and scanning Kelvin probe microscopy respectively. The increase in the work function, surface roughness as well as defect concentration with fluence, indicate the possibility of linear correlation between them. Presence of defects in graphene sheets strongly affects surface electronic and optical properties of the material that can be used to tailor the optoelectronics device performance.
RESUMEN
In this work, a few layer molybdenum disulfide (MoS2) and reduced graphene oxide (rGO) nanocomposite have been synthesized by liquid exfoliation method. The morphological and structural properties are analyzed using scanning electron microscopy and X-ray diffraction technique. The optical properties are also investigated using absorption and Raman spectroscopy. This report presents quantification of swift heavy ion irradiation induced defects using Raman spectroscopy. We found both Raman mode E12g and A1g corresponding to MoS2 and Raman modes of rGO are strongly affected by increasing ions doses. The defect induced lattice strain in the rGO/MoS2 nanocomposite is also estimated from Raman spectroscopy. MoS2 layers are found to be much more sensitive than rGO in the rGO/MoS2 nanocomposite. These types of study further used in device based application of rGO/MoS2 nanocomposite system.