Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5362820 | Applied Surface Science | 2009 | 5 Pages |
Abstract
We report the deposition of thin films of silver (Ag) nanoparticles by pulsed laser ablation in vacuum using the third line (355Â nm) of a YAG:Nd laser. The nanostructure and/or morphology of the films was investigated as a function of the number of ablation pulses, by means of transmission electron microscopy and atomic force microscopy. Our results show that films deposited with a small number of ablation pulses (500 or less), are not continuous, but formed of isolated nearly spherical Ag nanoparticles with diameters in the range from 1Â nm to 8Â nm. The effect of increasing the number of pulses by one order of magnitude (5000) is to increase the mean diameter of the globular nanoparticles and also the Ag areal density. Further increase of the number of pulses, up to 10,000, produces the formation of larger and anisotropic nanoparticles, and for 15,000 pulses, quasi-percolated Ag films are obtained. The presence of Ag nanoparticles in the films was also evidenced from the appearance of a strong optical absorption band associated with surface plasmon resonance. This band was widened and its peak shifted from 425Â nm to 700Â nm as the number of laser pulses was increased from 500 to 15,000.
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Authors
J.C. Alonso, R. Diamant, P. Castillo, M.C. Acosta-GarcÃa, N. Batina, E. Haro-Poniatowski,