One-step sputtering of MoSSe metastable phase as thin film and predicted thermodynamic stability by computational methods

• Published in: Scientific reports Vol. 14; no. 1; pp. 7104 - 11
• Main Authors: López-Galán, Oscar A., Boll, Torben, Nogan, John, Chassaing, Delphine, Welle, Alexander, Heilmaier, Martin, Ramos, Manuel
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 26.03.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1005/1007; 639/301/1034/1038; electronic devices; electronic structure; Fabrication; Humanities and Social Sciences; Mass spectroscopy; MATERIALS SCIENCE; Molybdenum; Molybdenum disulfide; multidisciplinary; Raman spectroscopy; Scanning electron microscopy; Science; Science (multidisciplinary); Selenium; Spectrum analysis; Sulfur; Thin films
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-57243-3

We present the fabrication of a MoS 2−x Se x thin film from a co-sputtering process using MoS 2 and MoSe 2 commercial targets with 99.9% purity. The sputtering of the MoS 2 and MoSe 2 was carried out using a straight and low-cost magnetron radio frequency sputtering recipe to achieve a MoS 2−x Se x phase with x = 1 and sharp interface formation as confirmed by Raman spectroscopy, time-of-flight secondary ion mass spectroscopy, and cross-sectional scanning electron microscopy. The sulfur and selenium atoms prefer to distribute randomly at the octahedral geometry of molybdenum inside the MoS 2−x Se x thin film, indicated by a blue shift in the A 1g and E 1 g vibrational modes at 355 cm −1 and 255 cm −1 , respectively. This work is complemented by computing the thermodynamic stability of a MoS 2−x Se x phase whereby density functional theory up to a maximum selenium concentration of 33.33 at.% in both a Janus-like and random distribution. Although the Janus-like and the random structures are in the same metastable state, the Janus-like structure is hindered by an energy barrier below selenium concentrations of 8 at.%. This research highlights the potential of transition metal dichalcogenides in mixed phases and the need for further exploration employing low-energy, large-scale methods to improve the materials’ fabrication and target latent applications of such structures.