Extraction of the Interface State Density of Top-Gate Graphene Field-Effect Transistors

Abstract

Novel electrical measurement method, discharge current analysis (DCA), is introduced to extract the density and energy distribution of charge traps at the dielectric interface of top-gate graphene field-effect transistors. Using DCA method, the highest charge trap density <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 10^{13}$ </tex-math></inline-formula> (cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-2}\cdot $ </tex-math></inline-formula> eV <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-1}$ </tex-math></inline-formula> ) is extracted at Fermi level <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 0.4$ </tex-math></inline-formula> eV. This is the first quantitative estimation of trap density at a specific Fermi level of graphene.