Charge exchange of heavy ions transmitted through a single layer of molybdenum disulfide

2D materials offer extraordinary optical, electronic and mechanical properties, which make them interesting for future applications. Modification techniques, like ion irradiation, allow to alter their properties to specific applications. However, because of their atomic thickness applied techniques have to address mainly the surface region. Highly charged ions are a novel tool for nanostructure formation. They carry potential energies up to tens of keV, which trigger the process of nanostructure formation due to the energy deposition in shallow depths in close vicinity of the surface region. Recently, HCI impact induced nanoholes in carbon nanomembranes [1] and in suspended monolayer MoS₂ [2] have been observed despite their atomic thickness limiting the amount of potential energy to be transferred. Here, we investigate the charge exchange of highly charged xenon ions passing a monolayer of MoS₂, from which we can obtain an upper estimate of the deposited energy. The exit charge states of transmitted ions are measured simultaneously with their scattering angle as well as with their time-of-flights [3]. Two distinct distributions at high and low charge states are visible. The different scattering angles indicate the existence of two impact parameter regimes leading to two (exit charge state) distributions. Our experimental results are supported by computer simulations using the Monte-Carlo code TDPot [4].
[1] R. A. Wilhelm et al., 2D Mater. 2, 035009 (2015).
[2] R. Kozubek et al., J. Phys. Chem. Lett. 10, 904-910 (2019).
[3] J. Schwestka et al., Rev. Sci Instrum. 89, 085101 (2018).
[4] R. A. Wilhelm and P. L. Grande, Commun. Phys. 2, 89 (2019).