Synthesis of CdSe/ZnS quantum dot composites for electroluminescent devices

Quantum dot composite films, consisting of II-VI nanocrystals imbedded in a ZnS matrix, are candidate phosphor materials for electroluminescent flat panel displays. The optical properties of such composites can be tailored across the visible spectral region by selecting the composition and size of the nanocrystals. We present combined solution chemistry and electrospray organometallic chemical vapor deposition (ES-OMCVD) methods for realizing such composites. Size selected, CdSe quantum dots with an overlayer of ZnS are synthesized in solution. This surface derivatization produces a large enhancement of the photoluminescence efficiency. The quantum dot composites are subsequently formed by introducing the quantum dot solution by electrospray into an OMCVD ZnS thin film process. Photoluminescence and cathodoluminescence properties of the quantum dot composites are reported.