Temperature dependence of the absorption edge of Cdsub(1-x)Mnsub(x)Te mixed crystals

The temperature and compositional dependence of the absorption band edge of Cdsub(1-x)Mnsub(x)Te mixed crystals up to x = 0.4 are measured between 4.2 and 400 K. It is found that for all compositions the portion of the absorption edge between 102 and 103 cm-1 changes exponentially with photon energy and the change of the slope is governed mainly by the exciton-phonon interaction. A decrease of the steepness of the tail with growing manganese content is observed and is attributed to alloying induced disorder. Some anomalies in the temperature dependence of the band edge of CdMnTe are observed and are explained by the influence of the unfilled Mn 3d shell on the sp3 bands of the alloy. (author)