Theoretical study of structural, electronic, and thermal properties of CdS, CdSe and CdTe compounds

A theoretical study of structural, electronic and thermal properties of CdS, CdSe and CdTe compounds is presented; using the full potential linearized augmented plane wave (FP-LAPW) method within density functional theory (DFT). In this approach, both the local density approximation (LDA) and the generalized gradient approximation (GGA) were used for the exchange-correlation potential calculation. The ground-state properties are determined for the bulk materials (CdS, CdSe and CdTe) in cubic phase. Quantities such as the lattice constants and bulk modulus of interest are calculated. Detailed comparisons are made with published experimental and theoretical data and show generally good agreement. Besides this, a numerical first-principles calculation of the elastic constants was used to calculate C-11, C-12 and C-44. The pressure dependence of band gaps for these systems was investigated. We also presented the thermal effects on some macroscopic properties of these compounds using the quasi-harmonic Debye model, in which the lattice vibrations are taken into account. We have obtained successfully the variations of the volume, thermal expansion coefficient, heat capacities and Debye temperature as a function of the pressure and temperature. (C) 2010 Elsevier B.V. All rights reserved.