Optical spectroscopy extinction method for sizing noble metal nanoparticles generated by femtosecond laser ablation of solid in liquids

. D. C. SCHINCA1, L. B. SCAFFARDI G. A. TORCHIA F. A. VIDELA, J. M. J. SANTILLÁN, P. MORENO3 AND L. ROSO

Salamanca

Conferencia; Ecamp10 European Conference on Atoms Molecules and Photons; 2010

In the last years, there has been an increasing interest in the generation of nanostructures using different methods. Concurrently, there is a constant need for sizing techniques atthe nanoscale, being transmission electron microscopy (TEM) the standard method. Optical methods arise as an alternative to TEM with competitive resolution and easiness ofsample handling and high statistics. This work presents results of sizing small silver and gold colloidal nanoparticles generated with fs laser ablation in water and ethanol based onoptical extinction spectra fitting. For particles much smaller than the incident wavelength, this fitting is based on the electrostatic approximation of Mie theory. We show that, for thecase of silver nanoparticles, the presence of a silver oxide shell around the silver core affects certain characteristics of the extinction spectrum, such as resonance wavelength, FWHMand contrast.