Phase control of two-dimensional tin sulfide compounds deposited via atomic layer deposition

Abstract

Two-dimensional (2D) semiconductor materials are emerging as potential candidates for emerging electronic device applications due to their excellent electrical properties and unique properties such as flexibility and transparency. Among the various potential 2D semiconductor materials, tin sulfide compounds can form polymorphs of different 2D crystals: 2D layered-SnS2 with hexagonal symmetry and 2D layered SnS with orthorhombic symmetry. In addition, since they each have different electrical and optical properties, their controlled growth is important for appropriate target applications. Therefore, we investigated the phase control of tin sulfide compounds deposited via atomic layer deposition according to their deposition temperature and post-annealing conditions. A strategy for controlling the growth of SnS2 or SnS was proposed by investigating phase transition tendencies according to deposition temperature and annealing conditions (temperature, pressure, atmosphere). As a result, it was possible to selectively deposit SnS2 and SnS thin films based on a phase transition study; it was confirmed that SnS2 and SnS thin films exhibited n-type and p-type semiconductor characteristics, respectively.