Impact of the Density and Oxygen Concentration of Initial Amorphous Carbon on Layer Exchange of Multilayer Graphene

Abstract

Layer exchange (LE) of amorphous carbon (a-C) is a promising method for fabricating high-quality multilayer graphene (MLG) on insulating substrates. We investigated the effects of initial a-C properties on the growth temperature and crystal quality of LE-MLG by controlling the a-C sputtering pressure (P a‑C). X-ray reflectivity and X-ray photoelectron spectroscopy revealed that the a-C density decreased and the O concentration in the a-C film increased with increasing P a‑C. LE occurred at the lowest temperature of 600 °C, reflecting a lower density and O concentration of a-C. Raman spectroscopy results showed that the crystal quality of LE-MLG improved with increasing P a‑C. Based on our results, we developed guidelines for the a-C properties in the LE technique to reduce the growth temperature and improve the crystal quality of MLG.