Ultrahigh electron mobility in suspended graphene

摘要: We have achieved mobilities in excess of 200,000 cm2 V− 1 s− 1 at electron densities of∼ 2× 1011 cm− 2 by suspending single layer graphene. Suspension∼ 150 nm above a Si/SiO2 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 …