A first-principles study on the structural, elastic, electronic, optical, lattice dynamical, and thermodynamic properties of zinc-blende CdX (X = S, Se, and Te)

The structural stability, elastic, electronic, optical, vibrational, and thermodynamic properties of the cubic compounds CdX (X = S/Se/Te) in zinc-blende structure have been investigated using a pseudopotential plane wave (PP-PW) method within the generalized gradient approximation (GGA) and the local density approximation (LDA). The use of the hybrid functionals sX-LDA/B3LYP lead to considerably improved electronic properties compared to standard GGA/LDA approaches. The calculated lattice parameters and bulk modulus agree reasonably with the previous results. The second-order elastic constants have been calculated and the derived debye temperatures are also obtained. The cohesive energy, band structure, density of states and electric charge density is as well given. On the other hand, an accurate calculation of linear optical functions (including the dielectric function, refraction index, reflectivity, conductivity function, and energy-loss spectrum) was performed. The obtained results are compared with other calculations and experimental measurements. Computed phonon and thermodynamic properties of CdX are in close accord with available experiments, and provide knowledge to be validated experimentally. (C) 2013 Elsevier B.V. All rights reserved.