Molecular-Scale Tailoring of Graphene Surface Chemistry via Organic Functionalization

Abstract

Graphene has emerged as one of the leading materials in condensed matter physics due to its superlative electrical and mechanical properties. With an eye towards expanding its functionality and applications, this paper highlights efforts to tailor the surface chemistry of graphene via organic functionalization. At the molecular scale, ultra-high vacuum (UHV) scanning tunneling microscopy (STM) is employed to characterize and nanopattern organically modified graphene. For example, a suite of perylene-based molecules form highly ordered self-assembled monolayers (SAMs) on graphene via gas-phase deposition in UHV. Due to their noncovalent bonding, these SAMs preserve the superlative electronic properties of the underlying graphene while providing uniform and tailorable chemical functionality. Alternatively, via aryl diazaonium chemistry, functional polymers are covalently grafted to graphene. In addition to presenting opportunities for graphene-based chemical and biological sensing, covalent grafting allows local tuning of the electronic properties of the underlying graphene.