Selective AuCl3 doping of graphene for reducing contact resistance of graphene devices

Abstract

Low contact resistance between metal-graphene contacts remains a well-known challenge for building high-performance two dimensional materials devices. In this study, CVD-grown graphene film was doped via AuCl3 solution selectively only to metal (Ti/Au) contact area to reduce the contact resistances without compromising the channel properties of graphene. With 10mM-AuCl3 doping, doped graphene exhibited low contact resistivity of ∼897Ωμm, which is lower than that (∼1774Ωμm) of the raw graphene devices. The stability of the contact resistivity in atmospheric environment was evaluated. The contact resistivity increased by 13% after 60days in an air environment, while the sheet resistance of doped graphene increased by 50% after 30 days. The improved stability of the contact resistivity of AuCl3-doped graphene could be attributed to the fact that the surface of doped-graphene is covered by Ti/Au electrode and the metal prevents the diffusion of AuCl3.