Published online by Cambridge University Press: 31 January 2011
Nanoscale metrology of graphene-based devices is a substantial challenge. The investigation of defects and stacking order is essential for graphene-based device development. Raman spectroscopy is a useful approach in this regard. The defect-induced Raman D band yields substantial insights regarding defect density and, consequently, can serve as in important tool to quantify impact of defects on eventual graphene-based device performance. Toward this end an investigation of electron beam-induced defects in bi-layer and mono layer graphene samples has been undertaken via the examination of the Raman D, and G bands. The evolution of the aforementioned Raman spectra as a function of electron beam dose was characterized via Raman spectroscopy and compared with spectra from the same samples prior to irradiation. Defect generation in the graphene as a function of electron beam dose was characterized via the change in the intensity ratios of the Raman D and G bands (ID/IG) and the broadening of the G band line width. Continued irradiation at very high flux and very low accelerating voltages have also revealed charge accumulation evident from the narrowing of G band line-widths.