Novel optical properties of ZnTe/CdSe superlattice

Type II ZnTe/CdSe superlattices were grown by molecular beam epitaxy on a GaAs substrate. Radiative type II transitions between electrons confined in the CdSe and holes confined in the ZnTe were observed in the photoluminescence spectra. For samples with thin CdSe layer, strong absorptive and weak emissive type I transitions, which involves both electrons and holes confined in the CdSe layer, were also found. For the radiative type II transitions, the excitonic activation energy decreases with CdSe layer thickness. While, for the type I emissive transitions, the excitonic activation energy increases with the CdSe layer thickness.