Silver nanoparticles prepared by laser ablation and their optical characteristics

Abstract

Laser-induced thermal explosion of metallic nanoparticles originates from nonlinear optical effect. Nonlinear optical properties of nanoparticle materials depend strongly on their size and shape. Several methods were proposed to produce nanoparticles of a controlled size and welldefined distribution. We studied to prepare silver nanoparticles by laser ablation. The characteristic spectral feature of the silver nanoparticles (peak around 400nm) was found in the absorption spectra measured by a UV-Vis 2450 spectrometer. The size and shape distribution of silver nanoparticles was observed and analyzed by a transmission electron microscope (JEM 1010- JEOL). Two different surfactants were employed namely trisodium citrate dihydrat C6H7Na3O7 and polyvinyl alcohol (-CH2-CHOH-)n. The size distribution and the UV-Vis absorption spectra of silver nanoparticles depend clearly on the properties and concentration of the surfactant employed. The experimental results were in good agreement with theory and showed advantages of the laser ablation method.