ملخص: The hydrostatic pressure dependence of the principal energy gaps and of the optical properties of PbX (X=S, Se, and Te) has been calculated with the use of the self-consistent full-potential linear muffin-tin orbital method. The local density approximation and density functional theory are applied. Structural properties such as the equilibrium lattice constants, the bulk modulus, and its pressure derivatives were calculated for lead chalcogenides in the rock salt structure (NaCl). We have found that the results of the structural properties calculations are in agreement with those of ab initio and experimental data. In the rock salt structure, the pressure dependence of the energy gaps of these compounds is overestimated compared to the available experimental data. However, for the same structure, the comparison of our results with those of ab initio calculations shows good agreement. On the other hand, the effect of the applied pressure is clearly seen in the optical response spectrum, especially near the energy transition regions.

لغة: إنجليزية