Graphene-edge probes for scanning tunneling microscopy

Abstract

Freestanding graphene-edge probes for scanning tunneling microscopy were demonstrated. Graphene was prepared on a Cu wire by thermal chemical vapor deposition (CVD) from solid carbon sources. Follow by a mechanical cutting process which was controlled by a micromanipulator and an optical microscope. The freestanding graphene probes were then fabricated. Our previous study of electron emission patterns from a field emission microscope demonstrated the layered structure of the graphene edge. We found that a single-layer of graphene emitted electrons comes from a limited number of atoms only when the graphene probe was conditioning carefully to achieve a stable emission current. In this research, we applied such activated graphene probes for use in scanning tunneling microscopes for surface morphology detection. The preconditioned, multi-layer graphene probe presented well resolution that was comparable to conventional Pt-Ir probes. Our study generated a practical method for applying individual freestanding graphene for surface probe microscopy with a cost effective process.