Xe Irradiation of Graphene on Ir(111): From Trapping to Blistering

TL;DR

This study reveals that keV Xe+ irradiation traps Xe atoms under graphene on Ir(111), leading to blister formation upon annealing, and combines experiments with simulations to understand and control this process for material synthesis and reactions.

Contribution

It uncovers the unexpected trapping mechanism of Xe under graphene on Ir(111) and demonstrates how to prevent or induce blistering for material engineering.

Findings

Xe atoms are trapped under graphene during irradiation.

Annealing causes Xe aggregation and blister formation.

Ion implantation can create blisters without damaging graphene.

Abstract

Using X-ray photoelectron spectroscopy, thermal desorption spectroscopy, and scanning tunneling microscopy we show that upon keV Xe + irradiation of graphene on Ir(111), Xe atoms are trapped under the graphene. Upon annealing, aggregation of Xe leads to graphene bulges and blisters. The efficient trapping is an unexpected and remarkable phenomenon, given the absence of chemical binding of Xe to Ir and to graphene, the weak interaction of a perfect graphene layer with Ir(111), as well as the substantial damage to graphene due to irradiation. By combining molecular dynamics simulations and density functional theory calculations with our experiments, we uncover the mechanism of trapping. We describe ways to avoid blister formation during graphene growth, and also demonstrate how ion implantation can be used to intentionally create blisters without introducing damage to the graphene layer. Our approach may provide a pathway to synthesize new materials at a substrate - 2D material interface or to enable confined reactions at high pressures and temperatures.