First-principles calculations of the structural, electronic, optical and elastic properties of the CuYS2 semiconductor.

The ternary semiconductor CuYS2 is studied by using the first-principles methods in the density functional theory (DFT) framework. The structural, electronic, optical and elastic properties were calculated at the ambient and elevated hydrostatic pressures. The compound was shown to have an indirect band gap of about 1.342/1.389 eV (in the generalized gradient and local density approximations, respectively). The anisotropy of the optical properties was studied by calculating the absorption spectra, dielectric function and index of refraction for different polarizations. The anisotropy of the elastic properties was visualized by plotting the three-dimensional dependence of the Young's moduli on the direction in the crystal lattice. The obtained results, which are reported for the first time to the best of the author's knowledge, can facilitate assessment of possible applications of the title material.