High-Throughput Computational Screening of Electrical and Phonon Properties of Two-Dimensional Transition Metal Dichalcogenides

Abstract

Two-dimensional transition metal dichalcogenides (2D-TMDs) are of broadening research interest due to their novel physical, electrical, and thermoelectric properties. Having the chemical formula MX2, where Mis a transition metal and X is a chalcogen, there are many possible combinations to consider for materials-by-design exploration. By identifying novel compositions and utilizing the lower dimensionality, which allows for improved thermoelectric performance (e.g. , increased See beck coefficients without sacrificing electron concentration), MX2 materials are promising candidates for thermoelectric applications. However, to develop these materials into wide-scale use, it is crucial to comprehensively understand the compositional affects. This work investigates the structure, electronic, and phonon properties of 18 different MX2 materials compositions as a benchmark to explore the impact of various elements. There is significant correlation between properties of constituent transition metals (atomic mass and radius) and the structure/properties of the corresponding 2D-TMDs. As the mass of M increases, the n-type power factor and phonon frequency gap increases. Similarly, increases in the radius of M lead to increased layer thickness and See beck coefficient S. Our results identify key factors to optimize MX2 compositions for desired performance.