Porous single layer molybdenum disulfide (MoS2) is a promising material for applications such as DNA sequencing and water desalination. In this work, we introduce irradiation with highly charged ions (HCIs) as a new technique to fabricate well-defined pores in MoS2. Surprisingly, we find a linear increase of the pore creation efficiency over a broad range of potential energies. Comparison to atomistic simulations reveals the critical role of energy deposition from the ion to the material through electronic excitation in the defect creation process, and suggests an enrichment in molybdenum in the vicinity of the pore edges at least for ions with low potential energies. Analysis of the irradiated samples with atomic resolution scanning transmission electron microscopy reveals a clear dependence of the pore size on the potential energy of the projectiles, establishing irradiation with highly charged ions as an effective method to create pores with narrow size distributions and radii between ca. 0.3 and 3 nm.
@article{arxiv.1907.01171,
title = {Perforating freestanding molybdenum disulfide monolayers with highly charged ions},
author = {Roland Kozubek and Mukesh Tripathi and Mahdi Ghorbani-Asl and Silvan Kretschmer and Lukas Madauß and Erik Pollmann and Maria O'Brien and Niall McEvoy and Ursula Ludacka and Toma Susi and Georg S. Duesberg and Richard A. Wilhelm and Arkady V. Krasheninnikov and Jani Kotakoski and Marika Schleberger},
journal= {arXiv preprint arXiv:1907.01171},
year = {2019}
}