Kelvin probe microscopy and electronic transport in graphene on SiC(0001) in the minimum conductivity regime

Abstract

Ambient-environment Kelvin probe microscopy of many (10 μm)2 areas of single-layer graphene on SiC(0001) shows area-to-area rms surface potential variation of 12 meV. Electronic transport data are consistent with the minimum conductivity regime. Together the data indicate a highly uniform carrier concentration with a small magnitude (< 1012cm -2). We conclude that the previously reported large spread in carrier densities from Hall measurements on similar samples is an artifact of electron-hole puddling in the minimum conductivity regime. © 2011 American Institute of Physics.