Exclusive Substitutional Nitrogen Doping on Graphene Decoupled from an Insulating Substrate

Abstract

The on-surface synthesis of atomically flat N-doped graphene on oxidized copper is presented. Besides circumventing the almost standard use of metallic substrates for growth, this method allows producing graphene with similar to 2.0 at % N in a substitutional configuration directly decoupled from the substrate. Angle-resolved photoemission shows a linear energy-momentum dispersion where the Dirac point lies at the Fermi level. Additionally, the N functional centers can be selectively tailored in sp(2) substitutional configuration by making use of a purpose-made molecular precursor: dicyanopyrazophenanthroline (C16H6N6).