Growth of ZnSe/ZnS strained-layer superlattice on Si substrates by atomic layer epitaxy

High-quality ZnSe-ZnS strained-layer superlattices were successfully grow on Si substrate by atomic layer epitaxy using a metal-organic chemical vapor deposition system. The characteristics of the ZnSe-ZnS strained-layer superlattices were investigated. Using photoluminescence measurements, an intense excitonic emission line and no emission due to deep levels were observed. As the ZnSe well-layer thickness increased, the peak of the line shifted markedly towards the lower-energy side. This behavior may be related to the quantum size effect, As the thickness of the ZnSe well-layer decreased, the activation energy increased. The ZnSe thickness is less than the three-dimensional exciton Bohr radius in bulk ZnSe. It is proposed that the dependence of the activation energy is due to two-dimensional exciton behavior in quantum wells. (C) 1997 Elsevier Science S.A.