FABRICATION OF ZNSE QUANTUM DOTS UNDER VOLMER-WEBER MODE BY METALORGANIC CHEMICAL-VAPOR-DEPOSITION

The possibility of fabricating quantum dots under Volmer-Weber growth mode is investigated. Layers of ZnSe/ZnS were grown by metalorganic ch emical vapor deposition on both Si and GaAs substrates. The images of surface morphology, taken by atomic force microscopy, showed that the layers were grown in three-dimensional islands. Blueshift was observed in the photoluminescence spectra up to room temperature for these sam ples. This blueshift was shown to originate from the ZnSe islands. The effect of ZnSe growth duration was investigated. It was found that th e blueshift increased with shorter ZnSe growth durations, but this nea r band gap emission disappeared when the ZnSe growth duration was long er than 5 s. Effects of quantum confinement and strain were considered to resolve the origin of the blueshift. Our result suggests that carr ier confinement plays a dominant role. (C) 1997 American Institute of Physics.