Rath, M. C. ; Mondal, J. A. ; Palit, D. K. ; Mukherjee, T. ; Ghosh, H. N. (2007) Femtosecond transient absorption studies in cadmium selenide nanocrystal thin films prepared by chemical bath deposition method Journal of Nanomaterials, 2007 (1). pp. 1-6. ISSN 1687-4110
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Official URL: http://www.hindawi.com/journals/jnm/2007/036271.ab...
Related URL: http://dx.doi.org/10.1155/2007/36271
Abstract
Dynamics of photo-excited carrier relaxation processes in cadmium selenide nanocrystal thin films prepared by chemical bath deposition method have been studied by nondegenerate femtosecond transient pump-probe spectroscopy. The carriers were generated by exciting at 400nm laser light and monitored by several other wavelengths. The induced absorption followed by a fast bleach recovery observed near and above the bandgap indicates that the photo-excited carriers (electrons) are first trapped by the available traps and then the trapped electrons absorb the probe light to show a delayed absorption process. The transient decay kinetics was found to be multiexponential in nature. The short time constant, <1 picosecond, was attributed to the trapping of electrons by the surface and/or deep traps and the long time constant, ≥20 picoseconds, was due to the recombination of the trapped carriers. A very little difference in the relaxation processes was observed in the samples prepared at bath temperatures from 25°C to 60°C.
Item Type: | Article |
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Source: | Copyright of this article belongs to Hindawi Publishing Corporation. |
ID Code: | 34227 |
Deposited On: | 31 Mar 2011 06:06 |
Last Modified: | 17 May 2016 17:07 |
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