Effect of Liquid Layer Thickness on the Ablation Efficiency and the Size-Control of Silver Colloids Prepared by Pulsed Laser Ablation

Sliver colloidal solutions were synthesized by Nd- YAG laser ablation 1064 nm of a high purity silver target immersed in deionised water. The effect of water layer thickness on the laser ablation efficiency of nanoparticles was investigated experimentally. UV-Vis spectrophotometer and transmission electron microscopy observations were employed to characterize the optical spectra and particle sizes of colloids, respectively. The optimum parameter of the water layer thickness (which yielded the maximum ablation efficiency) was determined. It was demonstrated that both- the average particle size and the ablation efficiency which can be tuned by choosing suitable experimental parameters of liquid layer thickness, laser fluence and post-ablation laser wavelength. Average particle size and redistribution of nanoparticles was controlled by the subsequent treatment of the ablated colloid solution with combination of 1064 and 532 nm pulses. The effects of post-ablation under laser-induced particle modification reduced the average particle size from 15.1 to 4.3 nm. Particle size distribution was also narrowed with 532 nm pulses.Â