ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 53, Number 6
JKCSEZ 53(6)
December 20, 2009 

ZnS:Mn/ZnS core-shell quantum dots (QDs), were synthesized via a thermal decomposition reaction of organometallic precursors in a hot solvent mixture. The synthetic conditions of the quantum dots were monitored at various reaction temperatures for the core formation, while the shell formation temperature was fixed at 135 oC. The obtained colloidal nanocrystals at corresponding temperatures were characterized by UV-Vis, solution photoluminescence (PL) spectroscopies, and further obtained powders were characterized by XRD, HR-TEM, and EDXS analyses. The synthetic temperature condition to obtain the best PL emission intensity for the core-shell QD was 135 oC, for both core and shell formation. At this temperature, solution PL spectrum showed a narrow emission peak at 583 nm with a relative PL quantum efficiency of 42.15%. In addition, the measured spherical particle sizes for the ZnS:Mn/ZnS nanocrystals via HR-TEM were in the range of 4.0 to 5.4 nm, while ellipsoidal particles were obtained at 150 oC.