PREPARATION AND CHARACTERIZATION OF ULTRAFINE ZINC-SULFIDE PARTICLES OF QUANTUM CONFINEMENT

We describe the preparation and characterization of highly monodispers ed, stabilized and size-fixed ZnS Q-particles. In these samples, small ZnS particles were well accommodated by beta-cyclodextrin cavities. T he included ZnS particle size was determined to be 9.7-12.2 angstrom b y scanning tunnel microscope, which is consistent with the inner diame ter of the cyclodextrin cavity. The microcrystalline structure was ide ntified to be of sphalerite-type by X-ray diffraction. A very sharp an d blue-shift exciton peak of optical absorption was observed at the 24 5-250 nm band and was well accounted for by a recent theoretical model based on a tight-binding approximation.