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

Document Type

Article

Publication Date

10-2016

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 M is 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 Seebeck 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 Seebeck coefficient S. Our results identify key factors to optimize MX2compositions for desired performance.

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