Theoretical Predictions for Elastic, Mechanical, Anisotropic, Electronic, and Optical Profiles of Wurtzite CdS, CdSe, and CdTe

Elastic, mechanical, anisotropic, electronic, and optical characteristics for the less commonly reported wurtzite (w) crystal structures of CdS, CdSe, and CdTe were investigated using density functional theory plus Hubbard formalism (DFT + U). Presently applied DFT + U methodology captures well the experimental bandgap orders of the w-CdS, w-CdSe, and w-CdTe structures with 2.44 eV, 1.87 eV, and 1.59 eV, respectively. Obtained optical results indicate the practical applications of the investigated compounds in infrared (IR) and ultraviolet (UV) wavelengths. The high-dielectric constant of 7.9 for w-CdTe also manifests the relatively high capacity of this compound for electrical energy storage. Moreover, the mechanical properties reveal the ductile character of wurtzite w-CdS, w-CdSe, and w-CdTe. Existing elastic anisotropy values of all compounds are reasonable compared to the available literature on these chalcogen semiconductors.