Abstract
We have achieved mobilities in excess of 200,000 cm 2 V −1 s −1 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, nonsuspended devices. This advance should allow for accessing the intrinsic transport properties of graphene.
Highlights
We have achieved mobilities in excess of 200,000 cm2V−1s−1 at electron densities of ∼2×1011 cm−2 by suspending single layer graphene
The experimental realization of graphene presents tantalizing opportunities to study phenomena ranging from the topological phase resulting in exotic quantum Hall states [1, 2] to the famous Klein paradox – the anomalous tunneling of relativistic particles [3]
The exact nature of the scattering that limits the mobility of graphene devices remains unclear, evidence has mounted that interactions with the underlying substrate are largely responsible
Summary
We have achieved mobilities in excess of 200,000 cm2V−1s−1 at electron densities of ∼2×1011 cm−2 by suspending single layer graphene. In this Letter we report the fabrication of electrically contacted suspended graphene and achieve a tenfold improvement in mobility as compared to the best values reported in the literature for traditional devices fabricated on a substrate. We conclude that our fabrication process results in graphene devices suspended ∼150 nm above SiO2 substrate (Fig. 1d).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
