The effect of bilayer regions on the response of epitaxial graphene devices to environmental gating

Ruth Pearce, Viktoria Eless, Arseniy Lartsev, I.L. Barker Snook, J.J. Helmore, Rositza Yakimova, J.C. Gallop, Ling Hao

Research output: Contribution to journalArticlepeer-review


The effect of a bilayer area on the electronic response to environmental gating of a monolayer graphene Hall bar device is investigated using room temperature magnetotransport and scanning Kelvin probe microscopy measurements in a controlled environment. The device is tuned through the charge neutrality point with n–p–n-junctions formed. Scanning Kelvin probe measurements show that the work function of the monolayer graphene decreases more than that of the bilayer area however magnetotransport measurements show a larger change in carrier concentration for bilayer graphene with environmental gating. Interface scattering at the boundary between the monolayer and bilayer regions also affects device response with field-dependent suppression of the conductivity observed near the charge neutrality point. Simultaneous electronic and environmental scanning Kelvin probe measurements are used to build nano-scale maps of the work function of the device surface revealing the areas of greatest work function change with environmental gating.
Original languageEnglish
Pages (from-to)896-902
Number of pages7
Early online date23 May 2015
Publication statusPublished - Nov 2015

Cite this