Physicists have identified a material that can conduct efficiently in multiple layers.

After the rush of interest in the atom-thick layers of carbon known as graphene, materials scientists turned to metal dichalcogenides — layered compounds that are also good conductors of electrical current. Rhenium disulphide now joins the promising candidates in this family.

Junqiao Wu at the Lawrence Berkeley National Laboratory in California and his colleagues discovered that bulk samples of the material have a direct bandgap, a gap in energy levels that can be used to absorb or emit light efficiently. Other members of the family have this type of bandgap only when isolated in monolayers.

Nature Commun. 5, 3252 (2014)