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Characterization of MHz pulse repetition rate femtosecond laser-irradiated gold-coated silicon surfaces

Sivakumar, Manickam and Venkatakrishnan, Krishnan and Tan, Bo (2011) Characterization of MHz pulse repetition rate femtosecond laser-irradiated gold-coated silicon surfaces. Nanoscale Research Letters, 6 (1). pp. 1-5.

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Official URL: http://www.nanoscalereslett.com/content/pdf/1556-2...

Abstract

In this study, MHz pulse repetition rate femtosecond laser-irradiated gold-coated silicon surfaces under ambient condition were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). The radiation fluence used was 0.5 J/cm2 at a pulse repetition rate of 25 MHz with 1 ms interaction time. SEM analysis of the irradiated surfaces showed self-assembled intermingled weblike nanofibrous structure in and around the laser-irradiated spots. Further TEM investigation on this nanostructure revealed that the nanofibrous structure is formed due to aggregation of Au-Si/Si nanoparticles. The XRD peaks at 32.2°, 39.7°, and 62.5° were identified as (200), (211), and (321) reflections, respectively, corresponding to gold silicide. In addition, the observed chemical shift of Au 4f and Si 2p lines in XPS spectrum of the irradiated surface illustrated the presence of gold silicide at the irradiated surface. The generation of Si/Au-Si alloy fibrous nanoparticles aggregate is explained by the nucleation and subsequent condensation of vapor in the plasma plume during irradiation and expulsion of molten material due to high plasma pressure.

Item Type:Article
Subjects:Physical Science > Nanophysics
Physical Science > Nano objects
Material Science > Nanochemistry
Material Science > Nanostructured materials
Divisions:Faculty of Engineering, Science and Mathematics > School of Physics
Faculty of Engineering, Science and Mathematics > School of Chemistry
ID Code:10956
Deposited By:JNCASR
Deposited On:16 Jul 2011 07:37
Last Modified:16 Jul 2011 07:37

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