Figure 1. Schematic illustration of graphene growth over liquid Ga supported on a W substrate.
(a) A droplet of Ga is placed on a W support foil. (b) CVD growth of graphene on the liquid Ga surface. (c) The as-grown graphene is coated with a PMMA layer by a spin-coating process. (d) Graphene coated with PMMA is gradually separated from the W foil driven by H2 bubbles produced at the interface between the graphene and the Ga–W substrate. (e) Graphene transferred onto a SiO2/Si substrate. (f) The W foil can be reused as Ga-support.