Disordered Electrical Potential Observed on the Surface of SiO2 by Electric Field Microscopy
Abstract
The electrical potential on the surface of 300 nm thick SiO2 grown on single crystalline Si substrates has been characterized at ambient conditions using electric field microscopy. Our results show an inhomogeneous potential distribution with fluctuations up to 0.4 V within regions of 1 μm. The potential fluctuations observed at the surface of these usual dielectric holders of graphene sheets should induce strong variations in the graphene charge densities and provide a simple explanation for some of the anomalous behaviors of the transport properties of graphene.
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