The unique properties of graphene, such as its gapless relativistic band structure and pseudospin magnetic character, have made this carbon-based material the focus of extremely numerous and diverse investigations during the last years. Such an extensive interest originates from the possibility of realizing graphene-based optolectronic and spintronic devices. The success of these potential applications depends, however, on the tunability of the electronic structure of graphene and a structural control at the nanoscale. In our group we develop methods to control the size and shape of graphene nanostructures and engineer their electronic structure by quantum confinement and using different metallic interfaces.

Controlling the shape of graphene nanosilands on Ni(111)

Epitaxial graphene islands grown on close-packed metal surfaces by decomposition of hydrocarbons usually present broad shape and size distributions. By using CVD to grow graphene nanoislands out of propene decomposition on the Ni(111) surface, we have been able to control the yield and shape of the nanoislands.  Carefully choosing the reaction/annealing parameters, we can go from irregular clusters to triangles and hexagons larger than 100 nm2 and with well-defined edges .

grafene nanoislands

Growth of graphene nanoislands of controlled shape on the Ni(111) surface. Propene is first dosed at room temperature and decomposed at around 450ºC, forming irregular islands. Higher annealing temperatures lead to the formation of triangular and hexagonal nanoislands.