Abstract
CdSe quantum dots (QDs) in a ZnMnSe diluted magnetic semiconductor (DMS) matrix were investigated using both energy- and polarization-selective magneto-photoluminescence (PL). The peaks from internal transition, CdSe QDs, and ZnMnSe barrier were observed in the experiment done using above-barrier excitation. By examining the dependence of the PL peak intensity on magnetic field we were able to identify the competition between the Auger-type energy transfer process (i.e., the energy transfer from band electrons to ions) and energy relaxation into CdSe QDs in this QD system. The role of energy transfer processes between band electrons and ions in the DMS QDs was further studied by using excitation energy below the ZnMnSe band gap, where no change in the intensity of internal transitions with magnetic field was observed, indicating that the energy transfer from carriers excited into the ZnMnSe barrier is indeed responsible for the intensity behavior of these internal transitions observed in DMS QD structures.
- Received 19 April 2005
DOI:https://doi.org/10.1103/PhysRevB.72.075320
©2005 American Physical Society