Spectroscopy and Femtosecond Dynamics of Type-II CdSe/ZnTe Core−Shell Semiconductor Synthesized via the CdO Precursor

Department of Applied Chemistry, National Chiao Tung University, Hsin-chu-hsien, Taiwan, Taiwan
The Journal of Physical Chemistry B (Impact Factor: 3.3). 06/2004; 108(30). DOI: 10.1021/jp049177w


CdSe/ZnTe type-II quantum dots (QDs) synthesized via the CdO precursor are reported. Spectroscopic and femtosecond dynamic measurements reveal that the rate of photoinduced electron/hole spatial separation decreases with increases in the size of the core, and it is independent of the thickness of the shell in the CdSe/ZnTe QDs. The results are consistent with the binding strength of the electron and hole confined at the center of CdSe. The correlation between the core/shell size and the electron/hole spatial separation rate resolved in this study may provide valuable information for applications where rapid photoinduced carrier separation followed by charge transfer into a matrix or electrode is crucial, such as in photovoltaic devices.

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    • "(2) Passivate the particle surface by bonding with an organic molecule and to improve the surface stability of NCs by reducing the lone pairs [15]. (3) Modify the surface by inorganic molecules (called coreshell structure) for the sake of increasing the electron-hole recombination efficiency [16] [17]. (4) Form alloyed NCs so as to eliminate the lattice mismatch and stress on the core-shell structures [9] [12]. "
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