Substrate-Selective Adhesion of Metal Nanoparticles to Graphene Devices

Nanostructured electronic devices, such as those basedon graphene,are typically grown on top of the insulator SiO2. Theirexposure to a flux of small size-selected silver nanoparticles hasrevealed remarkably selective adhesion: the graphene channel can bemade fully metallized, while the insulating substrate remains coverage-free.This conspicuous contrast derives from the low binding energy betweenthe metal nanoparticles and a contaminant-free passivated silica surface.In addition to providing physical insight into nanoparticle adhesion,this effect may be of value in applications involving deposition ofmetallic layers on device working surfaces: it eliminates the needfor masking the insulating region and the associated extensive andpotentially deleterious pre- and postprocessing.