Dielectric Screening Enhanced Performance in Graphene FET

Abstract

We have studied the transport properties of graphene transistors in different solvents with dielectric constant varying over 2 orders of magnitude. Upon increasing the dielectric constant, the carrier mobility increases up to 3 orders of magnitude and reaches ∼7 × 10⁴ cm²/v·s at the dielectric constant of ∼47. This mobility value changes little in higher dielectric constant solvents, which indicates that we are approaching the intrinsic limit of room temperature mobility in graphene supported on SiO₂ substrates. The results are discussed in terms of long-range Coulomb scattering originated from the charged impurities underneath graphene.