Analytic representation of the dielectric functions of InAsxSb1-x alloys in the parametric model

Abstract

We report expressions that allow the dielectric functions epsilon=epsilon(1)+ i epsilon(2) from 1.5 to 6.0 eV of InAsxSb1-x alloys over the entire composition range 0 <= x <= 1 to be calculated analytically. We base our work on the parametric model (PM), which describes the dielectric functions of semiconductor materials as a sum of Gaussian-broadened polynomials. Our reference e spectra are those that we obtained previously by spectroscopic ellipsometry for the specific compositions x=0.000, 0.127, 0.337, 0.491, 0.726, and 1.000. The PM reconstructions are in excellent agreement with the data, and with the interpolations provided here, the model is extended to arbitrary compositions. We expect these results to be useful in a number of contexts, for example for the design of optoelectronic devices. (C) 2012 Elsevier B. V. All rights reserved.