Nanoparticle production by pulsed laser fragmentation

A research cooperation between groups at the University of Duisburg-Essen and KIT has investigated the generation, structure and properties of ultrasmall gold clusters ranging from 1-3 nm in size. Such small clusters are normally not stable in liquids without covalent ligands. The astonishing observation of efficient luminscence was earlier ascribed to the ligand-cluster composite. The new study, with charge-stabilized unligated clusters, on the other hand, observes luminescence. This luminescence is even sensitive to size and charge state. X-ray spectrocopy has confirmed the conventional face-centered cubic crystal structure of these clusters.

Clusters produced by pulsed laser fragmentation (Image (c) the Authors under CC BY-NC 4.0)

This long-standing collaboration has previously investigated various processes of laser ablation of nanoparticles from targets in liquid (LAL) and laser fragmentation of nanoparticles into nanoclusters (LFL), with results which represent unique in-situ and ultrafast data on structure formation. As part of the (virtual) conference „Advanced Nanoparticle Generation and Excitation by Lasers in Liquids“ (ANGEL) held in Hefei (China) the Fojtik-Henglein Prize was awarded to Anton Plech (KIT) and Leonid Zhigilei (U. Virginia) for both the experimental clarification and theoretical modeling of ablation and fragmentation.

Further reading

In situ structural kinetics of picosecond laser-induced heating and fragmentation of colloidal gold spheres, Ziefuß, A.; Reich, S.; Reichenberger, S.; Levantino, M.; Plech, A., 2020. Physical chemistry, chemical physics, 22, 4993–5001. doi:10.1039/C9CP05202J