Epitaxial Growth of SnS 2 Ribbons on a Au-Sn Alloy Seed Film Surface.

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 (SnS 2 ) by using Au-Sn alloy film as a metal seed deposited on a sapphire substrate. Multilayer SnS 2 films were formed in a ribbon shape on (111)-oriented Au film and were aligned in the directions of threefold rotational symmetry. Furthermore, the SnS 2 was found to have an epitaxial relationship relative to the Au film and the sapphire substrate as follows: SnS 2 [2̅110] || Au[101̅] || Al 2 O 3 [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 SnS 2 ribbon formation.