COMPARISON OF OPTICALLY INDUCED LOCALIZED STATES IN CHALCOGENIDE GLASSES AND THEIR CRYSTALLINE COUNTERPARTS

Abstract
The below-gap peaks observed in the PLE spectra for deep PL bands in the minerals orpiment and realgar are attributed to strong impurity absorption bands, possibly associated with the high concentrations of 3d transition metals (e.g. Mn and Fe) detected by ESR. It is suggested that the weak below-gap tails in the PLE spectra of chalcogenide glasses and synthetic arsenic chalcogenide crystals have the same origin, but that impurity concentrations are much lower in these materials. Optically induced ESR spectra observed in crystalline arsenic chalcogenides are ascribed to paramagnetic Cu²⁺ ions rather than to the optically induced paramagnetic intrinsic defects associated with major constituent atoms as observed in chalcogenide glasses.