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Laser-Induced Growth of Monodisperse Silver Nanoparticles with Tunable Surface Plasmon Resonance Properties and a Wavelength Self-Limiting Effect.

NCJ Number
Journal of Physical Chemistry C Volume: 111 Dated: 2007 Pages: 14962-14967
Date Published
6 pages

This article reports on a method for the tunable production of monodisperse silver nanoparticles.  


Using monochromatic light of different laser wavelengths to irradiate an initial solution of seed crystals, the size and shape of the products can be controlled. By monitoring the absorption spectrum during growth, it was found that initially the absorption maximum shifted to longer wavelengths and broadened, indicating an increase in particle size and size dispersion. Remarkably, this effect came to a halt and reversed, displaying a shift to shorter wavelengths and simultaneously narrower bandwidths until, on completion, a final size and relatively narrow distribution were reached. The final size and shape were found to depend on laser wavelength and power. Both discs and triangular prisms as well as pyramidal and pentagonal prisms may be produced. A mechanism based on a wavelength-dependent self-limiting process governed by the surface plasmon resonance controlling the photochemical reduction of particles is suggested. (publisher abstract modified)

Date Published: January 1, 2007