Growth of CdS self-organized quantum dots by molecular beam epitaxy and application to light emitting diode structures

CdS quantum dots (QDs) were formed on ZnSe and ZnSxSe1-x. The nucleation pr ocess was monitored by reflection high energy electron diffraction, and it was suggested that QDs were formed without the wetting layer, The low tempe rature (13 K) photoluminescence (PL) measurement showed that the peak energ y could be controlled by the amount of the CdS deposit. The PL peak energy covered most: of visible range, indicating that the band lineup between CdS QD and ZnSe (or ZnSxSe1-x) host would be type II. Bright green and blue li ght emitting diode (LED) structures were fabricated in which CdS QDs were e mbedded in pn junctions of ZnSe and ZnSxSe1-x. The control of QD size as we ll as the band gap of the host material enabled the luminescence peak wavel ength of the LED to be varied. (C) 2000 American Vacuum Society.