Transfer-free electrical insulation of epitaxial graphene from its metal substrate

TL;DR

This paper presents a method to electrically insulate epitaxial graphene from its metal substrate using a step-wise intercalation process, enabling the use of graphene's transport properties without substrate interference.

Contribution

It introduces a novel transfer-free insulation technique for epitaxial graphene via silicon and oxygen intercalation forming a SiO₂ layer.

Findings

Successful insulation of graphene from Ru(0001) substrate

Electrical insulation confirmed by nano-scale multipoint probe

Intercalation process characterized by x-ray photoemission spectroscopy

Abstract

High-quality, large-area epitaxial graphene can be grown on metal surfaces but its transport properties cannot be exploited because the electrical conduction is dominated by the substrate. Here we insulate epitaxial graphene on Ru(0001) by a step-wise intercalation of silicon and oxygen, and the eventual formation of a SiO$_2$ layer between the graphene and the metal. We follow the reaction steps by x-ray photoemission spectroscopy and demonstrate the electrical insulation using a nano-scale multipoint probe technique.