ELECTROSPRAY ORGANOMETALLIC CHEMICAL-VAPOR-DEPOSITION - A NOVEL TECHNIQUE FOR PREPARATION OF II-VI QUANTUM-DOT COMPOSITES

A novel technique combining electrospray and organometallic chemical v apor deposition (OMCVD) has been developed for the synthesis of new II -VI quantum dot composites. CdSe nanocrystals (quantum dots) of select ed size are dispersed in a pyridine/acetonitrile mixture. The nanocrys tals art transferred by electrospray into the growth zone of an OMCVD reactor and codeposited on a ZnSe matrix grown from hydrogen selenide and diethyl zinc. Composites consisting of CdSe nanocrystals and an am orphous or polycrystalline ZnSe matrix have been deposited on glass su bstrates at temperatures of 150-250 degrees C. Room-temperature absorp tion and photoluminescence spectra show optical transitions characteri stic of the initial nanocrystal dispersions. The emission wavelength m ay be tuned in a broad spectral region by incorporating nanocrystals o f varying sizes. The composites have been characterized by Auger elect ron spectroscopy, high resolution transmission electron microscopy, an d scanning transmission electronmicroscopy. (C) 1994 American Institut e of Physics.