Optical properties of Hg1-xCdxTe/CdTe epitaxial films with graded band gap

Abstract

The IR transmission spectra of HgCdTe epitaxial films grown on CdTe substrates were measured. The films investigated contain an exponential composition gradient. Optical density D vs the photon energy (omega) are analyzed both theoretically and experimentally. Theoretical calculations of D((omega) ) spectra were performed in the framework of the WKB approximation. The composition profile has been obtained from the fitting procedure. In order to reduce the total amount of the fitting parameters as well as to improve the accuracy of this procedure the differentiation of the D((omega) ) curves were performed.