Electrostimulation and Nanomanipulation of Two-Dimensional MoO3-x Layers Grown on Graphite

• Published in: Crystals (Basel) Vol. 13; no. 6; p. 905
• Main Authors: Nadolska, Aleksandra, Kowalczyk, Dorota A., Lutsyk, Iaroslav, Piskorski, Michał, Krukowski, Paweł, Dąbrowski, Paweł, Le Ster, Maxime, Kozłowski, Witold, Dunal, Rafał, Przybysz, Przemysław, Ryś, Wojciech, Toczek, Klaudia, Kowalczyk, Paweł J., Rogala, Maciej
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-06-2023
• Subjects: Atomic force microscopy; conductive atomic force microscopy; Crystal defects; Current voltage characteristics; Electric contacts; Electrical properties; Electrical resistivity; Epitaxial growth; epitaxial molybdenum trioxide; Graphene; Graphite; Investigations; Islands; Lateral forces; Microscopy; Molybdenum; Molybdenum oxides; Molybdenum trioxide; Monolayers; nanomanipulation; Optoelectronic devices; Permittivity; Photoelectrons; Pyrolytic graphite; Spectrum analysis; Substrates; van der Waals structure
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst13060905

Molybdenum trioxide shows many attractive properties, such as a wide electronic band gap and a high relative permittivity. Monolayers of this material are particularly important, as they offer new avenues in optoelectronic devices, e.g., to alter the properties of graphene electrodes. Nanoscale electrical characterization is essential for potential applications of monolayer molybdenum trioxide. We present a conductive atomic force microscopy study of an epitaxially grown 2D molybdenum oxide layer on a graphene-like substrate, such as highly oriented pyrolytic graphite (HOPG). Monolayers were also investigated using X-ray photoelectron spectroscopy, atomic force microscopy (semi-contact and contact mode), Kelvin probe force microscopy, and lateral force microscopy. We demonstrate mobility of the unpinned island under slight mechanical stress as well as shaping and detachment of the material with applied electrical stimulation. Non-stoichiometric MoO3-x monolayers show heterogeneous behavior in terms of electrical conductivity, which can be related to the crystalline domains and defects in the structure. Different regions show various I–V characteristics, which are correlated with their susceptibility to electrodegradation. In this work, we cover the existing gap regarding nanomanipulation and electrical nanocharacterization of the MoO3 monolayer.