Substrate-Selective Adhesion of Metal Nanoparticles to Graphene Devices

TL;DR

This study demonstrates that small silver nanoparticles selectively adhere to graphene over silica, enabling metallization of graphene channels without masking, which could simplify device fabrication and improve precision.

Contribution

It reveals a substrate-dependent adhesion effect of nanoparticles, providing physical insight and potential practical applications in device manufacturing.

Findings

Nanoparticles adhere selectively to graphene over silica.

The adhesion is due to low binding energy on silica.

This effect allows metallization without masking.

Abstract

Nanostructured electronic devices, such as those based on graphene, are typically grown on top of the insulator SiO2. Their exposure to a flux of small size-selected silver nanoparticles has revealed remarkably selective adhesion: the graphene channel can be made fully metallized while the insulating substrate remains coverage-free. This conspicuous contrast derives from the low binding energy between the 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 of metallic layers on device working surfaces: it eliminates the need for masking the insulating region and the associated extensive and potentially deleterious pre- and postprocessing.