pISSN 0374-4914 eISSN 2289-0041

Research Paper

New Phys.: Sae Mulli 2021; 71: 225-229

Published online March 31, 2021 https://doi.org/10.3938/NPSM.71.225

Study of Two-dimensional Transition Metal Chalcogenide Alloys

Yeongrok JIN, Jaekwang LEE*

Department of Physics, Pusan National University, Busan 46241, Korea

Correspondence to:jaekwangl@pusan.ac.kr

Received: January 11, 2021; Revised: January 29, 2021; Accepted: February 15, 2021

Abstract

Using the cluster expansion methods and first-principles density functional theory calculations, we studied the mixing energy of 1H MoS$_{2-2x}$Te$_{2x}$ and 1T$^{\prime}$ MoS$_{2-2x}$Te$_{2x}$ binary alloys composed of the two-dimensional transition-metal chalcogenides MoS$_{2}$ and MoTe$_{2}$. For 1H MoS$_{2-2x}$Te$_{2x}$, a phase separation is expected due to the positive mixing energies regardless of the relative S and Te content. However, both MoS$_2$ and MoTe$_2$ can form solid solutions at temperatures above the room temperature because the mixing energy is less than 10 meV. In contrast, the mixing energies of 1T$^{\prime}$ MoS$_{2-2x}$Te$_{2x}$, alloys are always negative, resulting in the formation of a solid solution. We expect our theoretical studies to be utilized to guide the design of two-dimensional transition-metal chalcogenide alloys-based novel devices.

Keywords: Alloy, Mixing energy, Solid solution, Phase separation, Density functional theory