UV laser induced gold nanoparticle fabrication dependent on initial film properties

Abstract

The laser parameters, energy density and number of pulses, influence the UV laser-induced formation of gold nanoparticles on glass substrates. But also the deposition rate and the thickness of the gold layers used are important criteria for nanoparticle production. This is due to the fact that the resulting microstructures and the optical properties of the gold layers change by variation of sputtering power and deposition time based on different growth conditions of the films. The laser power of the KrF excimer laser used was varied from 50 to 500 mJ/cm2, the pulse number from 1 to 10 pulses and the film thickness from 20 nm to 60 nm as well. Low deposition rates produce layers with higher transparency for the same film thickness. The significant [111] texture of the films with grain sizes from 11 nm to 25 nm in dependent on the deposition rate, evaluated by x-ray diffraction and electron backscatter diffraction, changes after laser exposure. Particle size distributions were evaluated by scanning electron microscopy. Uni- or bi-modal distributions were observed dependent on deposition rate and laser parameters. The position and the width of nanoparticle plasmon resonances vary accordingly.