The effect of bilayer regions on the response of epitaxial graphene devices to environmental gating. (November 2015)

• Record Type: Journal Article
• Authors: Hill-Pearce, R.E.; Eless, V.; Lartsev, A.; Martin, N.A.; Barker Snook, I.L.; Helmore, J.J.; Yakimova, R.; Gallop, J.C.; Hao, L.
• Is Part Of: Carbon. Volume 93(2015)
• Page Start: 896
• Page End: 902
• Publication Date: 2015-11
• Subjects: Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2015.05.061
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: 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.