Spectroscopic Ellipsometry Studies of Cd1−xMnxTe Films Grown on GaAs

Abstract

Spectroscopic ellipsometry measurements of the complex dielectric function of a series of Cd1-xMnxTe (0 ≤ x ≤ 0.7) films grown on (100) GaAs by hot wall epitaxy have been performed in the 1.5-5.5 eV photon energy range at room temperature. The measured data were analyzed by fitting the second-derivative spectra (d2ε/dω2) with a theoretical model, namely, the standard critical-point (SCP) line shapes. It was found that the SCP model explains the measured derivative spectra successfully. The composition dependence of the critical-point (CP) energies and Lorentzian broadening (Γ) was determined.