The Effect of Laser Pulse Widths on Laser—Ag Nanoparticle Interaction: Femto- to Nanosecond Lasers

Abstract

Abstract:The effect of the laser pulse width on the production of nanoparticles by laser fragmentation was investigated. Laser pulse widths of 164 fs, 5 ps, 4 ns, 36 ns, 64 ns, and 100 ns were used. To assess the effect of the laser pulse width on the energy distribution in the nanoparticles, the energy distribution was simulated using wave optics. Silver (Ag) nanoparticles were produced by laser irradiation of an Ag target in distilled water. The wavelength of the femtosecond, picosecond, and nanosecond lasers used was 1070 nm, and their fluences were 0.10-0.13 mJ/cm 2 . Nanoparticle microstructure was visualized by transmission electron microscopy and scanning electron microscopy, and the nanoparticle size distribution was evaluated using a particle size analyzer.

RE-irradiation of silver nanoparticles obtained by laser ablation in water and assessment of their antibacterial effect

“…In our results the fragmentation effect is more noticeable in the case IR wavelength due to its higher fluence. Similar results have been reported in previous works, showing that particle size decrease by increasing the pulse fluence [38,36].…”

“…The SPR is a well-known metallic nanoparticles effect, since it is absent in individual atoms and in metallic bulk. It is associated to the nanoparticles shape, size and surrounding medium in a way that the presence of a single surface plasmon peak, implies that they are spherical [36][37]. The pronounced peak corresponds to the as-ablated nanoparticles while the broadening in the re-irradiated ones is characteristic of a wide size distribution [40] which is in agreement with the TEM observations.…”

“…As shown in Fig. 7a, the UV-VIS spectra of the synthesized nanoparticles exhibit a peak at approximately 400nm, which is characteristic of surface plasmon resonance (SPR) feature of Ag nanoparticle colloidal solutions [36]. The SPR is a well-known metallic nanoparticles effect, since it is absent in individual atoms and in metallic bulk.…”

“…Subsequently, the nanoparticles size was reduced by laser re-irradiation. This process causes a large number of small particles as well as a wider range of sizes [36] Note that all samples show a bimodal size distribution. In addition, the number of nanoparticles with a diameter lower than 10 nm increased with the re-irradiation times, primarily when the process is carried out with the IR laser.…”

Special Issue on Printed Electronics 2017

“…There is one paper dealing with production of nanoparticles. Jeon et al investigated the effect of the laser pulse width ranging from femtoseconds to nanoseconds on the mean diameter and the yield rate of Ag nanoparticles [5]. Laser beam controlled by a galvanometer scanner was irradiated onto Ag target in distilled water, and Ag nanoparticle produced by laser irradiation were analyzed using a transmission electron microscopy and a particle size analyzer.…”