No abstract

The photomodulated reflectivity (PR) spectroscopy of modulation-doped diluted magnetic semiconductor Cd0.72 Mn0.28 Te:In/CdTe multiple quantum wells has been measured at 20 K – 300 K. Several spectral features associated with intersubband transitions have been found. The feature associated with Fermi level is first reported in PR spectra of II–VI heterostructures. In addition, a abnormal transition intensity ratio of 22H to 11H caused by electron filled effect has been reported. The Photoluminescence(PL) spectra of the sample have also been measured at 10 K – 300 K. A strong enhancement of the photoluminescence intensity towards the electron Fermi energy, which is caused by multiple electron-hole scattering processes, is reported. The temperature dependence of the Fermiedge singularity has been measured and discussed. The mechanism of the Fermi-edge singularity can be explained by hole localization.