The Optical Parameters of Zn<sub>x</sub>Cd<sub>(1-x)</sub>Te Chalcogenide Thin Films

Abstract

A procedure to make optical quality thin films of Zn x Cd (1-x) Te by use of thermal evaporation of the ternary compound has been investigated. Structural and optical properties of Zn x Cd (1-x) Te solid solution with x = 0.1 to 0.5 were synthesized, from the resulting ZnTe and CdTe composition used in preparation of thin films. Structural investigation indicates they have polycrystalline structure. Composition was confirmed from EDAX while SEM picture shows homogeneity in films. Plots of (αhν) 2 versus (hν) yield straight line indicating direct transition occurs with optical band gap energies in the range 1.7 -2.3 eV. It is also found with increase Zn content the band gap of the films increases. Refractive indices and extinction coefficients have been evaluated in the spectral range (200 -2500 nm).