Room-Temperature All-Semiconducting Sub-10-nm Graphene Nanoribbon Field-Effect Transistors

Abstract

Sub-10 nm wide graphene nanoribbon field-effect transistors (GNRFETs) are studied systematically. All sub-10 nm GNRs afforded semiconducting FETs without exception, with $I_{\mathrm{on}}/I_{\mathrm{off}}$ ratio up to ${10}^6$ and on-state current density as high as $\sim 2000\mu \mathrm{A}/\mu \mathrm{m}$. We estimated carrier mobility $\sim 200{\mathrm{cm}}^2/\mathrm{V}\mathrm{s}$ and scattering mean free path $\sim 10\mathrm{nm}$ in sub-10 nm GNRs. Scattering mechanisms by edges, acoustic phonon, and defects are discussed. The sub-10 nm GNRFETs are comparable to small diameter ($d\le \sim 1.2\mathrm{nm}$) carbon nanotube FETs with Pd contacts in on-state current density and $I_{\mathrm{on}}/I_{\mathrm{off}}$ ratio, but have the advantage of producing all-semiconducting devices.