Pressure effect on the electronic spectra of CdSe and CdS

The effect of pressure on the electronic band structure of CdSe and CdS compounds has been investigated using the density functional theory. In this approach, the generalized gradient approximation (GGA) and the Purdue-Burke-Ernzerhof (PBEsol) parameterization were used for the exchange-correlation potential calculation. The ground-state properties are determined for the bulk materials (CdS and CdSe) in wurtzite phase. Structure and electronic properties are studied in the range of hydrostatic pressures between 0 and 100 GPa. The electron band-energy structure and density of states were calculated at different pressures. The equilibrium structural parameters, bulk modules and bandgaps are calculated and compared with the available experimental data and other theoretical results. The shift in the energy gap, total energy and lattice parameters of CdSe and CdS crystals with pressure is determined and compared with other known data.