| Autor: |
F J Zhang, L M Zhang, R O Claus |
| Zdroj: |
Smart Materials & Structures; Apr2007, Vol. 16 Issue 2, p243-248, 6p |
| Abstrakt: |
Based on femtosecond transient absorption spectroscopy, the charge carrier dynamics of CdSxSe1?xnanocrystal doped glasses was investigated by analyzing the nonlinear differential transient absorption spectra. Time constants were extracted, which are different from the literature results using similar samples: they are pump laser intensity-dependent and decrease with increasing pump laser intensity, whereas risetime constants are pump laser intensity-independent and high-order exciton recombination can be identified from the spectra. The threshold pump intensity was determined, which is lower than the literature result. Reasons for high-order recombination were analyzed, and broad size, state distribution and high pump intensity are found as key factors. Auger recombination may play a key role in the multi-exciton recombination. Theoretical calculations and analysis support this conclusion. A schematic model for electron transport and the formation of triexcitons in our samples are proposed to explain these results. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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