Deposition of Silver Nanoparticles Using Laser Pyrolysis

Abstract

Two lasers have been employed to deposit silver nanoparticles on quartz substrate by laser pyrolysis. Q-switched pulse Nd-YAG laser of (8 ns) pulse duration and RF CO₂ laser of CW operational mode have been used to synthesize silver nanoparticles from silver nitride diluted solution. The size and density of the nanoparticles vary according to the change in energy/ power, time and solution concentration. In addition to CO₂ laser parameters, the Scanning Speed is a crucial parameter which controls the properties of silver nanoparticles. It has been found that the smallest silver average size of 22.27 nm and a minimum surface roughness of (7.4 nm) have been obtained when the laser energy of Nd-YAG laser has been increased to 1joule. Nevertheless, when using RF CO₂ laser for the deposition of silver nanoparticles, it produces 21.65 nm average sizes and an at low scan speed of 0.4 mm/s. Moreover, the temperature analysis using COMSOL multiphysics software for the deposition process reveals that a maximum temperature of about 440 K has been achieved for higher laser energy1 J of Nd-YAG laser, while 850 K has been obtained when RF CO₂ laser with 0.4 mm/s scanning speed is used to deposit silver nanoparticles. The absorbance spectra of the films, which have been deposited by the laser pyrolysis indicate the formation of silver nanofilm of uniform nanoparticle size distributed by CW RF CO₂ when compared with the pulse Nd-YAG lasers. It has been also found that maximum absorption has appeared at 425 nm for silver nanofilms deposited on quartz for both types of lasers.