کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5404214 | 1505932 | 2006 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Ultrafast relaxation dynamics of electrons in Au clusters capped with dodecanethiol molecules
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
We have investigated electron relaxation dynamics of size-selected Au clusters capped by dodecanethiol molecules in the cluster sizes of 28-142 atoms using femtosecond pump-probe spectroscopy. Absorption spectra of 28-71-atom clusters show discrete peaks due to the optical transitions between quantized states, while an absorption band due to the surface plasmon is observed in 142-atom clusters. In the differential absorption spectra measured by the pump-probe experiments, a large redshift of 140Â meV lasting over 10Â ps and absorption bleaching decaying within 2Â ps are observed at the absorption peaks of 28-atom clusters. The redshift is ascribed to a charge transfer between Au clusters and dodecanethiol molecules adsorbed on the cluster surface, and the bleaching is due to blocking of the optical transitions between the ground state and the occupied electronic states due to the Pauli's-exclusion principle. Such behavior is in contrast to the 142-atom clusters, where the cooling of hot electrons generated by photo-excitation determines the relaxation dynamics. These results indicate molecular properties of the 28-atom Au cluster-dodecanethiol system.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volumes 119â120, JulyâOctober 2006, Pages 423-427
Journal: Journal of Luminescence - Volumes 119â120, JulyâOctober 2006, Pages 423-427
نویسندگان
Y. Hamanaka, K. Fukagawa, Y. Tai, J. Murakami, A. Nakamura,