Map of Two-Dimensional Tungsten Chalcogenide Compounds (W–S, W–Se, W–Te) Based on USPEX Evolutionary Search

Abstract

New two-dimensional nanostructures of W–X composition (X = S, Se, Te) are predicted using the evolutionary algorithm implemented in the USPEX software package. Based on the results, two new thermodynamically and dynamically stable two-dimensional W3S5 and W5Te2 structures are proposed. The density functional theory study of the electronic and optical properties of these monolayers is carried out. It is demonstrated that the predicted W3S5 and W5Te2 structures show semiconducting properties with band gaps of 0.62 and 0.40 eV, respectively, and the calculated extinction spectrum indicates a broad absorption band in the visible spectral range, making these materials promising for applications in photovoltaics and solar energy.