Accelerated synthesis of atomically-thin 2D quantum materials by a novel laser-assisted synthesis technique. (21st November 2019) - Azam, Nurul
Abstract: Two-dimensional (2D) layered materials including transition metal dichalcogenides (TMDCs) have recently been at the heart of the quantum materials and information sciences research due to unusual properties associated with their firmly defined dimensionalities. Many efforts have focused on developing new methods for the accelerated growth and discovery of 2D materials, including physical and chemical vapor deposition techniques. However, the synthesis of these multi-component crystals in the gas phase has been extremely challenging due to complex and uncontrolled gas-phase reactions and flow dynamics. Here, we demonstrate a novel laser-assisted synthesis technique (LAST), which significantly reduces the existing growth complexities and notably accelerates the growth of 2D materials. This approach facilitates the growth of various 2D materials directly from stoichiometric powders by laser vaporization process. We show that directed laser heating allows pressure-independent decoupling of the growth and evaporation kinetics enabling the use of stoichiometric powder as precursors for the growth of high-quality 2D materials including MoS2, MoSe2, WSe2, and WS2 . A comprehensive experimental study was conducted to identify the system behavior, including the evaporation and growth parameters as well as the process-property relationships. This method presents a general yet simple approach for accelerating the discovery of emerging quantum materials.