Ultrahigh electron mobility in suspended graphene
arXiv:0802.2389 · doi:10.1016/j.ssc.2008.02.024
Abstract
We have achieved mobilities in excess of 200,000 cm^2/Vs at electron densities of ~2*10^11 cm^-2 by suspending single layer graphene. Suspension ~150 nm above a Si/SiO_2 gate electrode and electrical contacts to the graphene was achieved by a combination of electron beam lithography and etching. The specimens were cleaned in situ by employing current-induced heating, directly resulting in a significant improvement of electrical transport. Concomitant with large mobility enhancement, the widths of the characteristic Dirac peaks are reduced by a factor of 10 compared to traditional, non-suspended devices. This advance should allow for accessing the intrinsic transport properties of graphene.
4 pages, 3 figures, references updated