Atmospheric doping effects in epitaxial graphene: correlation of local and global electrical studies
Journal article, 2016

We directly correlate the local (20 nm scale) and global electronic properties of a device containing mono-, bi- and tri-layer epitaxial graphene (EG) domains on 6H-SiC (0001) by simultaneously performing local surface potential measurements using Kelvin probe force microscopy and global transport measurements. Using well-controlled environmental conditions we investigate the doping effects of N-2, O-2, water vapour and NO2 at concentrations representative of the ambient air. We show that presence of O-2, water vapour and NO2 leads to p-doping of all EG domains. However, the thicker layers of EG are significantly less affected. Furthermore, we demonstrate that the general consensus of O-2 and water vapour present in ambient air providing majority of the p-doping to graphene is a common misconception. We experimentally show that even the combined effect of O-2, water vapour, and NO2 at concentrations higher than typically present in the atmosphere does not fully replicate p-doping from ambient air. Thus, for EG gas sensors it is essential to consider naturally occurring environmental effects and properly separate them from those coming from targeted species.

Kelvin probe force microscopy

epitaxial graphene

gas sensor

environmental doping

Hall sensor


V. Panchal

National Physical Laboratory (NPL)

C. E. Giusca

National Physical Laboratory (NPL)

Arseniy Lartsev

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

N. A. Martin

National Physical Laboratory (NPL)

N. Cassidy

University of Surrey

National Physical Laboratory (NPL)

R. L. Myers-Ward

Naval Research Laboratory

D. K. Gaskill

Naval Research Laboratory

O. Kazakova

National Physical Laboratory (NPL)

2D Materials

2053-1583 (eISSN)

Vol. 3 1 015006

Graphene-Based Revolutions in ICT And Beyond (Graphene Flagship)

European Commission (EC) (EC/FP7/604391), 2013-10-01 -- 2016-03-31.

Subject Categories

Condensed Matter Physics



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