Growth and electronic transport properties of epitaxial graphene on SiC

With the aim of developing a single-crystal graphene substrate indispensable to graphene's practical applications, we are investigating the structural and physical properties of graphene epitaxially grown on SiC by thermal decomposition. We grow monolayer and bilayer graphene uniformly on a micrometre scale on the Si face of SiC in an Ar environment and in ultra-high vacuum, respectively. Epitaxial bilayer graphene, even if uniform in thickness, contains two types of domains with different stacking orders. We compare the transport properties of monolayer and bilayer graphene using top-gate Hall bar devices. Quantum Hall effects are observed in monolayer graphene and a band gap is electrically detected in bilayer graphene. The monolayer and bilayer graphene show quite different transport properties, reflecting their electronic structures.