Ni2Csurface carbide to catalyze low-temperature graphene growth

Abstract

The possibility to grow a graphene layer using the chemical-vapor-deposition technique over a Ni 2 C/Ni(111) substrate has been identified experimentally, with the advantage of having a lower processing temperature (T < 500 • C), compared to standard growth over a Ni(111) surface. To understand the role of the metal carbide/metal catalyst, we first perform a static study of the Ni 2 C/Ni(111) structure and of the binding and removal of a carbon atom at the surface, using both a tight-binding (TB) energetic model and ab initio calculations. Grand-canonical Monte Carlo TB simulations then allow us (i) to determine the thermodynamic conditions to grow graphene and (ii) to separate key reaction steps in the growth mechanism explaining how the Ni 2 C/Ni(111) substrate catalyzes graphene formation at low temperature.