Determining the Thickness and Refractive Index of Epitaxial Thin Films of CdxZn(1-x)Se by means of the reflectance spectra

Abstract

Calculations of thickness and refraction index of epitaxial thin films of CdxZnxSe by means of the reflectance spectra are reported in this work. The experimental reflectance spectra were analyzed and fitted using a simple function with the same oscillatory argument of the reflectivity coefficient of the heterostructure. The thickness of the layers was calculated considering the data of the refraction index in function of the photon energy and alloy composition reported by Suzuki et al.1 and the interference extremes within transparency region above 1.4 eV. It was confirmed that the dispersion law of the refractive index of epitaxial thin films of CdxZnxSe can be expressed in terms of an empiric relationship similar to the Wemple - DiDomenico single oscillator model with good approximation in the whole transparency region. These results could facilitate the analysis and design of optoelectronic devices based on thin layers of this alloy.