Achievement

Will Gannett finds scalable routes to high mobility graphene devices through novel synthesis techniques. In graphene, interaction with substrates can drastically increase carrier scattering (and thus reduce carrier mean free path). By using boron nitride produced by the National Institute for Materials Science in Japan as an underlayer for chemical vapor deposition (CVD)-grown graphene, he showed that this underlayer alone increased the electron mobility by an order of magnitude, and thus concluded that the intrinsic scattering (e.g. from defects and grain boundaries) in CVD graphene can be made very low. This shows that electronic transport in graphene that is on silicon dioxide substrates is dominated by doping effects from the silicon dioxide itself. He fabricated similar samples for the Crommie group at UC Berkeley, who then observed these doping effects directly with scanning tunneling microscopy.