OPTICAL-CONSTANTS OF ZN1-XCDXTE TERNARY ALLOYS - EXPERIMENT AND MODELING

The optical spectra of Zn1-xCdxTe ternary alloys in the 1.1-5.6-eV photon-energy range at room temperature have been measured by spectroscopic ellipsometry (SE). The optical constants reported here are the complex dielectric constant (epsilon = epsilon1 + iepsilon2), complex refractive index (n* = n + ik), absorption coefficient (a) and normal-incidence reflectivity (R). The measured data are analyzed on the basis of a simplified model of the interband transitions. The experimental data reveal distinct structures in the optical spectra at energies of the E0, E0 + DELTA0, E1, E1 + DELTA1 and E2 transitions, and are in reasonable agreement with the theoretical model. The model proposed here enables us to obtain the optical response in Zn1-xCdxTe alloys of arbitrary composition (x) and photon energy (E = HBARomega).