Energy Gaps, Optical Transitions, and Exciton Properties of ZnSe at High Pressures

Abstract

Lattice parameters, band-gap energies, optical transitions and exciton properties of ZnSe at high-pressures up to 100 kbar have been studied using a pseudo-potential method. Results are generally in good agreement with experiment at zero pressure. Adachi’s expression formula for exciton binding energy and Bohr radius are adjusted giving a significant accordance with experiments. A very good accord is acquired between our obtained consequences concerning the refractive index and the high-frequency dielectric constant when using Hervé and Vandamme model. Upon compression up to 100 kbar, ZnSe remains a direct (Γ-Γ) semiconductor. The lattice parameter decreases from 5.6692 to 4.9075 Å, whereas the valence band width increases from 11.47 to 15.35 eV. A monotonic behavior has been found for all parameters of interest under hydrostatic pressure.