Microwave-assisted size control of CdS nanocrystallites

Citation
Y. Wada et al., Microwave-assisted size control of CdS nanocrystallites, J MAT CHEM, 11(7), 2001, pp. 1936-1940
Citations number
36
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
JOURNAL OF MATERIALS CHEMISTRY
ISSN journal
0959-9428 → ACNP
Volume
11
Issue
7
Year of publication
2001
Pages
1936 - 1940
Database
ISI
SICI code
0959-9428(2001)11:7<1936:MSCOCN>2.0.ZU;2-N
Abstract
The size and size-distribution of CdS nanocrystallites is controlled by the microwave-assisted reaction of cadmium acetate with thiourea in N,N-dimeth ylformamide (DMF). The absorption onset of the CdS nanocrystallites shifts to longer wavelength with increasing irradiation time, indicating particle size growth under prolonged irradiation. However, when the microwave irradi ation of the solution is periodically interrupted and then repeated, keepin g the solution at ambient temperature before each irradiation, the absorpti on onset remains at the same wavelength and only the optical density of the absorption band is increased, suggesting that the particle growth occurs o nly during the continuous irradiation and stops once the system is cooled d own. Photoluminescence observed for the CdS nanocrystallites changes with t he irradiation time and the repetition of the irradiation, suggesting a str uctural change of the nanocrystallite surface due to the consumption of exc ess Cd2+.