title: Spectroscopy and femtosecond dynamics of type-II CdTe/CdSe core-shell quantum dots.
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.
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei 106, Taiwan. chop@ntu.edu.tw
authors.forename: Pi-Tai
authors.initials: PT
authors.lastname: Chou
authors.forename: Chun-Yen
authors.initials: CY
authors.lastname: Chen
authors.forename: Chiu-Ting
authors.initials: CT
authors.lastname: Cheng
authors.forename: Shih-Chieh
authors.initials: SC
authors.lastname: Pu
authors.forename: Kun-Chan
authors.initials: KC
authors.lastname: Wu
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Cheng
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Lai
authors.forename: Yi-Hsuan
authors.initials: YH
authors.lastname: Chou
authors.forename: Hsin-Tien
authors.initials: HT
authors.lastname: Chiu