Self-organized van der Waals epitaxy of layered chalcogenide structures

• Published in: Physica Status Solidi. B: Basic Solid State Physics Vol. 252; no. 10; pp. 2151 - 2158
• Main Authors: Saito, Yuta, Fons, Paul, Kolobov, Alexander V., Tominaga, Junji
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing Ltd 01.10.2015
• Subjects: Chalcogenides; Deposition; Epitaxy; Insulators; layered chalcogenides; Monolayers; Sb2Te3; Self-organized growth; Sputtering; topological insulators; Topology; Transition metals; van der Waals epitaxy
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.201552335

Highly oriented Sb2Te3 films were successfully deposited by RF‐magnetron sputtering on both crystalline and amorphous substrates. A novel deposition mechanism and method are proposed based on van der Waals epitaxy. Due to the selective reactivity of the top surface atoms of the substrate with sputtered atoms, a Te monolayer is the first layer formed on the substrate, resulting in the subsequent layer‐by‐layer growth of the Sb2Te3 film independent of the crystallinity of the substrates. We believe that this method can be applied to the mass production of a wide range of various van der Waals solids, such as transition metal dichalcogenides and topological insulators for future electronics devices. Self‐organized van‐der‐Waals epitaxy was proposed as a possible growth mechanism of highly‐oriented layered chalcogenide materials, like Sb2Te3, by sputtering. It was found that depending on the composition of the substrate, there existed a selectivity of the chemical reaction between the film and substrate elements that resulted in the preferential formation of a Te monolayer and subsequent layer‐by‐layer growth of Sb2Te3. This novel mechanism enables one to fabricate highly‐oriented chalcogenide films over a large area and can be applied to the mass production of a wide range of various van‐der‐Waals solids, such as transition metal dichalcogenides and topological insulators for future electronics devices.