Optical properties of ZnSe, ZnCdSe and ZnSSe alloys doped with iron

Ionisation (2 + -to-3 + or 1 +) and intra-shell transitions of iron in bulk crystals of ZnS, ZnSe, CdSe and in their alloys are studied. The results o f these studies allow us to verify the recent theoretical predictions on un iversal reference levels due to transition metal ions and to explain the na ture of Fe-related nonradiative transitions ill ZnSe. We also demonstrate l imitations of the Ludwig-Woodbury model for the description of intra-shell transitions of Fe2+. (C) 2000 Elsevier Science B.V. All rights reserved.