Synthesis of Wrinkled MoS 2 Thin Films Using a Two-Step Method Consisting of Magnetron Sputtering and Sulfurization in a Confined Space

Considering the increasing need for sustainable and economical energy storage solutions, the integration of layered materials such as MoS 2 into these systems represents an important step toward enhancing energy sustainability and efficiency. Exploring environmentally responsible fabrication techniques, this study assesses wrinkled MoS 2 thin films synthesized from distinct Mo and MoS 2 targets, followed by sulfurization conducted in a graphite box. We utilized magnetron sputtering to deposit precursor Mo and MoS 2 films on Si substrates, achieving thicknesses below 20 nm. This novel approach decreases sulfur by up to tenfold during sulfurization due to the confined space technique, contributing also to avoiding the formation of toxic gases such as SO 2 or the necessity of using H 2 S, aligning with sustainable materials development. Thinner MoS 2 layers were obtained post-sulfurization from the MoS 2 precursors, as shown by X-ray reflectometry. Raman spectroscopy and grazing X-ray diffraction analyses confirmed the amorphous nature of the as-deposited films. Post-sulfurization, both types of films exhibited crystalline hexagonal MoS 2 phases, with the sulfurized Mo showing a polycrystalline nature with a (100) orientation and sulfurized MoS 2 displaying a (00L) preferred orientation. The X-ray photoelectron spectroscopy results supported a Mo:S ratio of 1:2 on the surface of the films obtained using the MoS 2 precursor films, confirming the stoichiometry obtained by means of energy dispersive X-ray spectroscopy. Scanning electron microscopy and atomic force microscopy images revealed micrometer-sized clusters potentially formed during rapid cooling post-sulfurization, with an increased average roughness. These results open the way for the further exploration of wrinkled MoS 2 thin films in advanced energy storage technologies.