Femtosecond dynamics of CdTe quantum dots in water
- 作者：Mikel Sanz ; Miguel A. Correa-Duarte ; Luis M. Liz-Marzá ; n ; Abderrazzak Douhal
- 关键词：Femtosecond ; Cadmium telluride ; Quantum dots ; Fluorescence ; Ultrafast dynamics ; Electron ; Holes ; Relaxation ; Recombination
- 刊名：Journal of Photochemistry and Photobiology A ; Chemistry
- 出版年：2008
- 期刊代码：66_10106030
- 类别：ch
- 出版时间：30 April 2008
- 卷：196
- 期：1
- 页码：51-58
- 文件大小：609 K
摘要
We present studies on femtosecond to nanosecond fluorescence dynamics of aqueous solutions of cadmium telluride (CdTe) quantum dots (QDs) with diameters of 3.1 and 3.6 nm. Ultrafast times in the range 200–320 fs and 1.6 ps were determined, and assigned to electron relaxation to the bottom of the conduction band and to recombination of trapped electrons and holes. These times are common to the relaxation mechanisms of QDs in solution, and therefore suggests that intrinsic mechanisms for electron and hole relaxation dominate over surface effects, in agreement with other reports. Additionally, times of 
es/223c.gif" alt="not, vert, similar" title="not, vert, similar" border="0">40 ps, es/223c.gif" alt="not, vert, similar" title="not, vert, similar" border="0">600 ps and es/223c.gif" alt="not, vert, similar" title="not, vert, similar" border="0">20 ns due to radiative transitions were recorded. These results are relevant to understanding the photodynamics of CdTe and other QDs in water which should play a fundamental role in their signal when used in biological media.