Spectroscopy and femtosecond dynamics of type-II CdTe/CdSe core-shell quantum dots

被引：43

作者：

Chou, PT

Chen, CY

Cheng, CT

Pu, SC

Wu, KC

Cheng, YM

Lai, CW

Chou, YH

Chiu, HT ^{[1
]}

机构：

[1] Natl Taiwan Univ, Dept Chem, Taipei 106, Taiwan

[2] Natl Chiao Tung Univ, Dept Appl Chem, Hsinchu 300, Taiwan

来源：

CHEMPHYSCHEM | 2006年 / 7卷 / 01期

关键词：

D O I：

10.1002/cphc.200500307

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

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 interbond 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 inter-band 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 X 10(12) s(-1). The finite rates of the initial charge separation ore tentatively rationalized by the small electron-phonon coupling, causing weak coupling between the initial and charge-separated states.

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页码：222 / 228

页数：7

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