title: Composition-tunable Zn(x)Cd(1-x)Se nanocrystals with high luminescence and stability.
abstract: High-quality Zn(x)Cd(1-x)Se nanocrystals have been successfully prepared at high temperature by incorporating stoichiometric amounts of Zn and Se into pre-prepared CdSe nanocrystals. With increasing Zn content, a composition-tunable emission across most of the visible spectrum has been demonstrated by a systematic blue-shift in emission wavelength. The photoluminescence (PL) properties for the obtained Zn(x)Cd(1-x)Se nanocrystals (PL efficiency of 70-85%, fwhm = 22-30 nm) are comparable to those for the best reported CdSe-based QDs. In particular, they also have good PL properties in the blue spectral range. Moreover, the alloy nanocrystals can retain their high luminescence (PL efficiency of over 40%) when dispersed in aqueous solutions and maintain a symmetric peak shape and spectral position under rigorous experimental conditions. A rapid alloying process was observed at a temperature higher than "alloying point". The mechanism of the high luminescence efficiency and stability of Zn(x)Cd(1-x)Se nanocrystals is explored.
authors.affiliation: Department of Materials Science, National University of Singapore, Singapore.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Zhong
authors.forename: Mingyong
authors.initials: M
authors.lastname: Han
authors.forename: Zhili
authors.initials: Z
authors.lastname: Dong
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: White
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Knoll