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Updated: Aug 13, 2026

Compact Quantum Dots for Single-molecule Imaging
Published on: October 9, 2012
Spectroscopy and femtosecond dynamics of type-II CdTe/CdSe core-shell quantum dots
Pi-Tai Chou1, Chun-Yen Chen, Chiu-Ting Cheng
1Department of Chemistry, National Taiwan University, Taipei 106, Taiwan. chop@ntu.edu.tw
Abstract:
Syntheses of CdTe/CdSe type-II quantum dots (QDs) using CdO and CdCl2 as precursors for core and shell, respectively, are reported. Characterization was made via near-IR interband emission, transmission electron microscopy (TEM), energy dispersive spectroscopy (EDX), and X-ray diffraction (XRD). Femtosecond fluorescence upconversion measurements on the relaxation dynamics of the CdTe core (in CdTe/CdSe) emission and CdTe/CdSe interband emission reveal that as the size of the core increases from 5.3, 6.1 to 6.9 nm, the rate of photoinduced electron separation decreases from 1.96, 1.44 to 1.07 x10(12) s(-1). The finite rates of the initial charge separation are tentatively rationalized by the small electron-phonon coupling, causing weak coupling between the initial and charge-separated states.
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