Forbidden band width and effective charge in crystal lattice of ZnS

The optical and thermal widths of the forbidden band are determined by the absorption spectrum and temperature dependence of the conductivity respectively. The difference between them is determined also by the spectral sensitivity of different phosphors to optical stimulation. The effective charge of an ion in ZnS is determined in several ways by using the value of this difference, the refractive index, dielectric constant and frequencies in the Raman spectrum and the spectrum of infra-red absorption of ZnS. It was found to be equal to approximately half of the electron charge.