OPTICAL EXTINCTION FOR DETERMINING SIZE DISTRIBUTION OF GOLD NANOPARTICLES FABRICATED BY ULTRASHORT PULSED LASER ABLATION

G. A. TORCHIA; L. B. SCAFFARDI; CRUZ MÉNDEZ; PABLO MORENO; J. O. TOCHO; LUIS ROSO

APPLIED PHYSICS. A - MATERIALS SCIENCE AND PROCESSING

Springer

Lugar: Berlín; Año: 2008 vol. 93 p. 967 - 971

0947-8396

This work presents a method based on measurements of optical extinction spectra to determine the size of spherical gold nanoparticles produced using femtosecond laser ablation process in deionized water, with a fluence of »1000 J/cm2. By using an improved theoretical model that modifies the contribution of the free electrons to the dielectric function introducing a size-dependant term, it is possible to fit the full experimental extinction spectrum considering a determined size distribution [1]. Additionally, in order to verify this size distribution, TEM analysis was performed. The results obtained showed that the predominant nanoparticles size distributions ranges from 1 nm to 11 nm radii. Optical extinction measurement together with an appropriate theoretical model from Mie´s theory [2] represent an efficient, simple, low cost, fast and easy method to describe a multimodal size distribution of spherical gold nanoparticles.