RAMAN-SCATTERING STUDIES OF CD1-XMNXTE FILMS GROWN ON GAAS BY PULSED LASER EVAPORATION AND EPITAXY

We have used Raman scattering to study a series of thin (111) Cd(1-x)Mn(x)Te (CMT) films grown on (111) GaAs by pulsed laser evaporation and epitaxy. We show Raman spectra of CMT with 0.059 less-than-or-equal-to x less-than-or-equal-to 0.70, at 80 K. Samples with x > 0.4 exhibit up to 8th order combinations of CdTe-like and MnTe-like longitudinal optical phonons, which vary with excitation energy between 2.4 and 2.7 eV. We interpret these overtones as arising from outgoing resonance with the fundamental gap, and present an equation for the mth order phonon line intensity. We confirm the dependence of phonon frequency on x(Mn), and examine the variation of the phonon mode intensities with x(Mn). We also discuss the line widths of Raman and photoluminescence spectra versus x(Mn).