Nanostructures were fabricated on natural MoS 2 crystals by bombardment with low doses of Ar + and He + with energies ranging from 100 to 5 keV. The bombarded surfaces were investigated with x-ray photoemission spectroscopy ͑XPS͒ and scanning tunneling microscopy ͑STM͒ in an ultrahigh vacuum environment. The ion exposures were low enough to ensure that the observed nanostructures can be associated with individual ion impacts. Argon ions ͑Ar + ͒ with energies of 100 eV or less remove very few, if any, sulfur atoms from the surface but STM and XPS studies reveal that the electronic structure of the MoS 2 surface is altered. Ar + with energies greater than 100 eV has a higher probability of sputtering sulfur atoms from the surface. The apparent size of the nanostructures in the STM images increased with Ar + energies up to about 1 keV and was dependent on the angle of incidence of the Ar + . Helium ion ͑He + ͒ sputtering of MoS 2 produced similar but smaller nanostructures when compared to Ar + at the same impinged ion energy. STM images showed bright ring-shaped features were created with He + energies greater than 500 eV. On the basis of XPS and current imaging tunneling spectroscopy investigations, the features are assigned to sulfur atom vacancies. A change in the surface doping type from n to p was observed upon light sputtering of the surface.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.