Simplified conceptual illustration showing an electrical charge between two layers of graphene. Graphene is an allotrope of carbon in the form of a two-dimensional,atomic-scale,hexagonal lattice in which one atom forms each vertex. It is the basic structural element of other allotropes,including graphite,charcoal,carbon nanotubes and fullerenes. It can also be considered as an indefinitely large aromatic molecule,the limiting case of the family of flat polycyclic aromatic hydrocarbons. Graphene has many extraordinary properties. It is about 207 times stronger than steel by weight,conducts heat and electricity efficiently and is nearly transparent. Researchers have known that bilayer graphene,consisting of two stacked graphene layers,acts more like a semiconductor when immersed in an electric field |