Epitaxial Growth of SnS2 Ribbons on a Au-Sn Alloy Seed Film Surface

J Phys Chem Lett. 2022 Jul 7;13(26):6147-6152. doi: 10.1021/acs.jpclett.2c00906. Epub 2022 Jun 28.

Abstract

Two-dimensional metal chalcogenide film has attracted considerable interest for its use as an emerging device material for nanoelectronics. The film has been synthesized by various methods such as chemical vapor deposition, molecular beam epitaxy, and thermal vapor sulfurization. In this study, we took a new approach to synthesize tin disulfide (SnS2) by using Au-Sn alloy film as a metal seed deposited on a sapphire substrate. Multilayer SnS2 films were formed in a ribbon shape on (111)-oriented Au film and were aligned in the directions of threefold rotational symmetry. Furthermore, the SnS2 was found to have an epitaxial relationship relative to the Au film and the sapphire substrate as follows: SnS2[2̅110] || Au[101̅] || Al2O3[011̅0]. The segregation of grains consisting of a Sn-rich phase on the Au film surface and the subsequent sulfurization of these grains can be the key to the epitaxial SnS2 ribbon formation.