DYNAMICS OF LOCALIZED EXCITONS AND HIGH-EXCITATION EFFECTS IN II-VI QUANTUM-WELLS AND HETEROSTRUCTURES

We investigate and discuss two aspects that are of importance for II-VI lasers, namely the dynamics of excitons and the high excitation processes capable to show optical gain. In the first case we concentrate on CdTe/ZnTe quantum wells, which exhibit an especially pronounced inhomogeneous broadening due to disorder. We investigate the relaxation of excitons under emission of optical and acoustic phonons. For the second topic we start with bulk II-VI compounds and proceed to thin layers, heterostructures and quantum wells, showing that excitonic effects are more important for II-VI laser materials as compared to the more established III-V compounds for the (infrared, which are dominated by an electron-hole plasma.