Premium
Preparation‐Condition Dependence of Hybrid SiO 2 ‐Coated CdTe Nanocrystals with Intense and Tunable Photoluminescence
Author(s) -
Yang Ping,
Murase Norio
Publication year - 2010
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200901900
Subject(s) - photoluminescence , materials science , nanocrystal , cadmium telluride photovoltaics , quenching (fluorescence) , ion , coating , chemical engineering , quantum dot , sulfur , bioconjugation , nanotechnology , optoelectronics , optics , fluorescence , organic chemistry , chemistry , physics , engineering , metallurgy
When aqueously prepared CdTe nanocrystals (NCs) are coated with a SiO 2 shell containing Cd ions and a sulfur source, they show a drastic increase in photoluminescence (PL) efficiency with a significant red shift and spectral narrowing after reflux. This is ascribed to the creation of a hybrid structure characterized by the formation of CdS‐like clusters in the vicinity of the NCs in the SiO 2 shell. Since these clusters are close to the NCs, their effective size increases to reduce the quantum size effect. The dependences of the PL properties on the preparation conditions are systematically investigated. The PL efficiency increases from 28% to 80% in the best case with a red shift of 80 nm. The PL behaviors differ from those of normal CdTe NCs and include less temperature quenching and longer PL lifetime. The SiO 2 coating enables bioconjugation with IgG without deterioration of PL efficiency, making hybrid NCs amenable for bioapplication.