First-principles calculations of optical properties of GeC, SnC and GeSn under hydrostatic pressure

We present first-principles of the full-potential linearized augmented plane wave calculations of the effect of hydrostatic pressure on the optical properties of zinc-blende GeC, SnC and GeSn compounds. The refractive index and its variation with hydrostatic pressure are well described. An accurate calculation of linear optical functions (refraction index and its pressure derivative, and both imaginary and real parts of the dielectric function) is performed in the photon energy range up to 15 eV. The predicted optical constants agree well with the available experimental and theoretical ones.