Amorphous-to-Crystal Transition in Quasi-Two-Dimensional MoS₂: Implications for 2D Electronic Devices

Abstract

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have demonstrated a very strong application potential. In order to realize it, the synthesis of stoichiometric 2D TMDCs on a large scale is crucial. Here, we consider a typical TMDC representative, MoS2, and present an approach for the fabrication of well-ordered crystalline films via the crystallization of a thin amorphous layer by annealing at 800 °C, which was investigated in terms of long-range and short-range orders. Strong preferential crystal growth of layered MoS2 along the ⟨002⟩ crystallographic plane from the as-deposited 3D amorphous phase is discussed together with the mechanism of the crystallization process disclosed by molecular dynamic simulations using the Vienna Ab initio Simulation Package. We believe that the obtained results may be generalized for other 2D materials. The proposed approach demonstrates a simple and efficient way to fabricate thin 2D TMDCs for applications in nano- and optoelectronic devices.