Optical Constants of In1-xGaxSb Ternary Alloys: Experiment and Modeling

Abstract
The optical response of In1-x Ga x Sb ternary alloys in the 1.5-5.4-eV photon-energy range at room temperature is measured by spectroscopic ellipsometry (SE). The measured SE data show distinct structures at energies of the E 1, E 11, E 0 , E 0 0 , E 2 and E 1 critical points. These spectra are analyzed on the basis of a simplified model of interband transitions. The model proposed here enables us to obtain the optical response in In1-x Ga x Sb alloys of arbitrary composition (x) and photon energy (E=\hbarω). Results of the surface-treatment effect on the pseudodielectric functions are also presented.