II-VI quantum dots (QDs) have been Linder debate on their ripening properties for some time, and a unified understanding of this phenomenon will be given in this paper. Improvement of QD size uniformity is the main concern for practical applications. Scaling of the dot size distributions on some II-VI QDs will be discussed for the better understanding of the size distributions and for the improvement of the dot size uniformity. QD size distributions also tend to smear out the special features of QDs which are expected to modulate electron-photon interactions in optical microcavities coupled with QDs. Study of energy relaxation processes in QDs reveals the possibility of selectively exciting QDs which are in resonance with longitudinal optical (LO)-phonon emission processes. This scheme will be applied to the study of the strong coupling regime of optical microcavities coupled with QDs. CdS/ZnS QDs embedded in pyramidal three-dimensional microcavities are also examined to study the capability to observe enhanced spontaneous emissions by the coupling with cavity modes in pyramidal microcavities. (C) 2002 Elsevier Science B.V. All rights reserved.