CATHODOLUMINESCENCE AND PHOTOLUMINESCENCE OF HIGHLY LUMINESCENT CDSE ZNS QUANTUM-DOT COMPOSITES/

We report room-temperature cathodoluminescence and photoluminescence s pectra originating from ZnS overcoated CdSe nanocrystals, 33 and 42 An gstrom in diameter, embedded in a ZnS matrix. The thin-film quantum do t composites were synthesized by electrospray organometallic chemical vapor deposition. Cathodoluminescence and photoluminescnece are domina ted by the sharp band-edge emission characteristic of the initial nano crystals. The emission wavelength can be tuned in a broad window (470- 650 nm) by varying the size of the dots. The cathodoluminescence inten sity depends on the crystallinity of the ZnS matrix and the voltage an d current density applied. (C) 1997 American Institute of Physics.