Characterization of ZnO Nanoparticles Grown by Laser Ablation of a Zn Target in Neat Water

Abstract

Figure 1. X-ray diffraction spectrum of ZnO nanoparticles formed via laser ablation of a Zn target in deionized water. The most frequently-employed technique to synthesize nanoparticles in liquid is the chemical reduction of metal ions. As an alternative, laser ablation of a metal target in liquid has proven to be a powerful tool to prepare nanoparticles in liquid. In particular, it is an attractive technique for fabrication of various metal oxide nanoparticles emersed in liquid phase since it has overwhelming advantages, compared to the chemical reduction, such as technical simplicity, chemical pureness, and controlled synthesis. To be more concrete, nanoparticles can be formed in neat solvent like deionized water just by impinging on the target by a high-power pulsed laser beam without any supplementary chemicals. The unique feature of laser ablation in liquid is the formation of dense plasma which brings about local and temporal non-equilibrium conditions. Accordingly, not only the chemical environment but also physical parameters including laser power and spot size, wavelength, and ablation time determine the characteristics of the resultant nanoparticles. In this respect, it will be certainly beneficial to verify the influence of such parameters not only for producing high-quality nanoparticles but also for deep understanding of the physical processes their-in. Here, we present experimental results on the formation of ZnO nanoparticles via liquid laser ablation, which clearly demonstrate the effects of ablation time, aging, and laser power on the photoluminescence properties including the relative intensity of the UV and visible region.