Nanoscale design of 2D metal contacts on 2D materials

The goal of the proposed project is to develop the fundamental understanding required for growth of thin noble-metal (Ag and Au) films with two-dimensional (2D) morphology on graphene.

This is a key step for fabricating high-quality multifunctional metal contacts and, thereby, integrating graphene and other 2D materials in novel devices.

Achieving 2D morphology entails a great scientific challenge; weak interaction between most metal atoms and 2D crystals provides a strong driving force for uncontrolled formation of three-dimensional metal islands.

Our recent discoveries unlock an innovative path for addressing this challenge, without compromising other physical properties of the film/substrate system.

This path encompasses the use of our thin-film synthesis route MIMSI (modulated impulse magnetron sputtering interplay) to control the nanoscale atomic arrangement at the film growth front by deploying gaseous (N2 and O2) and less-noble-metal (Cu and Al) minority species (surfactants) with high temporal and spatial precision.

Inspired by and leveraging these discoveries, we seek to attain the project goal in a four-year research program during which we will strategically combine (i) surfactant-modified film growth; (ii) nanoscale structural and chemical characterization; and (iii) stochastic film-growth simulations.

Beyond 2D-material-based devices, the project is expected to generate knowledge for triggering the transition to a new era of multiscale materials design.