title: Visualisation of edge effects in side-gated graphene nanodevices.
abstract: Using local scanning electrical techniques we study edge effects in side-gated Hall bar nanodevices made of epitaxial graphene. We demonstrate that lithographically defined edges of the graphene channel exhibit hole conduction within the narrow band of ~60-125 nm width, whereas the bulk of the material is electron doped. The effect is the most pronounced when the influence of atmospheric contamination is minimal. We also show that the electronic properties at the edges can be precisely tuned from hole to electron conduction by using moderate strength electrical fields created by side-gates. However, the central part of the channel remains relatively unaffected by the side-gates and retains the bulk properties of graphene.
authors: 1] National Physical Laboratory, Teddington, TW11 0LW, United Kingdom [2] Royal Holloway, University of London, Egham, TW20 0EX, United Kingdom.
authors: Vishal
authors: V
authors: Panchal
authors: Chalmers University of Technology, Göteborg, S-412 96, Sweden.
authors: Arseniy
authors: A
authors: Lartsev
authors: Istituto Nazionale di Ricerca Metrologica, Strada delle Cacce, 91-10135 Torino, Italy.
authors: Alessandra
authors: A
authors: Manzin
authors: Linköping University, Linköping, S-581 83, Sweden.
authors: Rositza
authors: R
authors: Yakimova
authors: 1] National Physical Laboratory, Teddington, TW11 0LW, United Kingdom [2] Royal Holloway, University of London, Egham, TW20 0EX, United Kingdom.
authors: Alexander
authors: A
authors: Tzalenchuk
authors: National Physical Laboratory, Teddington, TW11 0LW, United Kingdom.
authors: Olga
authors: O
authors: Kazakova