Formation and photoluminescence of stacked CdSe quantum dots grown by molecular beam epitaxy

We have investigated formation and optical properties of single-layer and s tacked self-assembled CdSe quantum dots (QDs) by reflection high-energy ele ctron diffraction (RHEED), plan-view transmission electron microscope (TEM) image, and photoluminescence (PQ spectra. We have demonstrated a useful te chnique to control the dot size using the RHEED intensity observation durin g CdSe growth. The RHEED intensity significantly changes with the increase of CdSe coverage. The TEM observation reveals that the dot structures are f ormed at the minimum of the RHEED intensity variation. Using this technique , we have fabricated stacked QDs. The excitation power dependence of the PL spectra indicates the vertically coupling effect on thin ZnSe spacer sampl es. (C) 2001 American Vacuum Society.