Spectroscopic ellipsometry and photoluminescence investigation of Zn1–xyBex Mgy Se and Cd1–xyBex Zny Se crystals



Optical and luminescence properties of the Bridgman-grown Cd1–xyBex Zny Se and Zn1–xyBex Mgy Se crystals are reported. Spectroscopic ellipsometry was employed for determination of spectral dependence of the complex dielectric function equation image(E) in the photon energy range 0.75–6.5 eV. Below the absorption edge the refractive indices n (E) of the alloys were modelled using a Sellmeier-type relation. The excitonic band-gap energies were estimated from the ellipsometric and photoluminescence measurements. Compositional effects in the ellipsometric and photoluminescence spectra are discussed. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)