Modifications in structural, optical and electrical properties of epitaxial graphene on SiC due to 100Â MeV silver ion irradiation

Epitaxial graphene (EG) on silicon carbide (SiC) is a combination of two robust materials that are excellent candidates for post silicon electronics. In this work, we systematically investigate structural changes in SiC substrate as well as graphene on SiC and explore the potential for controlled applications due to 100 MeV silver swift heavy ion (SHI) irradiation. Raman spectroscopy showed fluence dependent decrease in intensity of first and second order modes of SiC, along with decrease in Relative Raman Intensity upon ion irradiation. Similarly, Fourier-transform infrared (FTIR) showed fluence dependent decrease in Si-C bond intensity with presence of C=O, Si-O-Si, Si-Si and C-H bond showing introduction of vacancy, substitutional and sp3 defects in both graphene and SiC. C1s spectra in XPS shows decrease in C=C graphitic peak and increase in interfacial layer following ion irradiation. Reduction in monolayer coverage of graphene after ion irradiation was observed by Scanning electron microscopy (SEM). Further, UV-Visible spectroscopy showed increase in absorbance of EG on SiC at increasing fluence. I-V characterization showed fluence dependent increase in resistance from 62.9 Ω in pristine sample to 480.1 Ω in sample irradiated at 6.6 × 1012 ions/cm2 fluence. The current study demonstrates how SHI irradiation can be used to tailor optoelectronic applicability of EG on SiC.