Speaker
Description
2D membranes are promising building blocks in various fields, but their advanced use often requires functionalisation of their surface and the modification of their physiochemical properties. Functionalisation can be achieved with defects and the incorporation of foreign atomic species. Various methods are available for this, but major challenges still lay in the control of the defect types and their concentrations. Ion irradiation at ultra-low energies (< 100 eV) offers a powerful tool to create modifications with controlled type and concentration in 2D materials by adjusting the kinetic energy of the ion and the exact number of the ions.
In this talk, I will discuss our recent efforts in applying this methodology to functionalise and manipulate 2D materials. Specifically, I will review our recent results on introducing substitutional metal atoms in graphene [1,2], and how these functional sites can be used as anchors to build single atom thick planar metal structures (metallenes) on the graphene surface [3]. Further, I will discuss our recent work with few-layer thick MoS2 membranes, focusing on ion irradiation induced defect engineering of the 2D surface and trapping atoms in-between the membranes for electronic band structure modification [4]. Our approach encompasses both experimental and computational routes, including characterisation with atomic resolution electron microscopy and Raman spectroscopy accompanied with molecular dynamics and density functional theory calculations.
[1] Trentino,.., Åhlgren et al. Micron 184, 103667, 2024.
[2] Trentino,.., Åhlgren, 2D Materials 9, 025011, 2022.
[3] Joudi, .., Åhlgren, ACS Nano 19, 22032-22043, 2025.
[4] Nawaz, James.., Åhlgren, unpublished.