Microwave-enhanced exciton delocalization in low-dimensional CdTe/CdMnTe and CdMnTe/CdMgTe quantum well structures

In this work we describe new application of the technique of optically detected cyclotron resonance (ODCR) to studies of localization processes in quantum well structures of CdTe/CdMnTe and CdMnTe/CdMgTe. Interaction between microwave-heated free carriers, at cyclotron resonance conditions, and either site- or impurity-localised excitons results in modification of photoluminescence from the sample. in consequence, cyclotron resonance of free carriers can be detected optically. We show here that the technique of ODCR allows us to monitor processes of carrier/exciton localisation and also to evaluate their influence on radiative recombination processes in quantum well structures. We conclude that localization effects to explain operation of CdTe/CdMnTe and CdMnTe/CdMgTe structures as high modulators. (author)