Graphene transistor. Coloured scanning electron micrograph (SEM) of a transistor composed of a graphene wire (centre), gold electrodes (dark yellow) and silicon (blue). The graphene wire is 200 nanometres (billionths of a metre) wide. Graphene is composed of a single layer of carbon atoms arranged in a honeycomb crystal lattice. It is both flexible and very strong. It conducts electrons faster than silicon and could one day replace silicon in applications such as nanometre (billionths of a metre) sized electronics, cheap and efficient solar panels, transparent window coatings and miniature sensing technologies. Graphene was discovered by Andre Geim in 2004.