Effect of ablation time and laser fluence on the optical properties of copper nano colloids prepared by laser ablation technique

Abstract

Copper (Cu) nanoparticles of average sizes (radius in nm) varying between 1.7 and 6 nm have been prepared by 1,064 nm Nd:YAG laser ablation of solid copper target in water medium. The nanostructures of the samples have been characterized using high-resolution transmission electron microscopes (HRTEM). The UVvisible absorption spectra obtained with a UV-visible spectrophotometer show sharp absorptions in the ultraviolet region and visible region due to the interband transition and surface plasmon resonance (SPR) oscillations in Cu nanoparticles, respectively. The increase in the linewidth of the SPR absorption peaks with the reduction in particle sizes are observed due to the intrinsic size effects. The behaviour of the UV-visible spectra associated with the Cu nanoparticles is studied as a function of laser fluence and laser ablation time.

A simple strategy for enhanced production of nanoparticles by laser ablation in liquids

“…The distinct SPR absorption bands of Cu and Ag NPs in the Vis [21][22], could be affected by their sizes and shapes. Specifically, band positions and intensities were associated to the agglomeration extent , as well as to the size distribution of Ag NPs [26,[60][61][62][63][64][65] and to the shell, or partial oxidation of Cu NPs [24,58,[66][67][68][69]. Since for Ag NPs very slight shifts in wavelength peaks positions vs. ablation fluences were observed, it is reasonable to assume that the mean diameter of the resulting particles was not changed for different fluences [61,63].…”

ZnO Nano Particles (NPs) Properties Prepared by Liquid Phase Laser Ablation (LPLA)

“…As predicted the increase in the number of laser pulses lead to increase the quantity of NPs in the suspension, these nano particles will intercept the laser beam incident on the target when they gathered near the surface of the ethanol after many laser pulses. This will create more complication during the laser energy absorption by the nano particles size reduction [8]. …”

Effects of water depth and laser pulse numbers on size properties of colloidal nanoparticles prepared by nanosecond pulsed laser ablation in liquid

“…With increasing number of laser pulses, more nanoparticles are produced and they get close together near the laser spot [22,27]. After producing sufficiently large number of nanoparticles, a large number of them cover the target surface, which leads to a decrease of the energy absorption by it and to a consequent reduction of the ablation rate.…”

“…After producing sufficiently large number of nanoparticles, a large number of them cover the target surface, which leads to a decrease of the energy absorption by it and to a consequent reduction of the ablation rate. Such condition causes no further increase in the number of particles [22,23]. Besides, primarily synthesized nanoparticles absorb a large fraction of the laser pulse energy that leads to size reduction of the nanoparticles.…”

“…Effects of water depth above target and number of laser pulses on size properties of colloidal nanoparticles have been investigated by a few numbers of authors [21,22]. For example, it was shown that particle' size decreases by increasing water depth [21].…”