Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7908700 | Optical Materials | 2016 | 6 Pages |
Abstract
We determine the extinction values of silver nanoparticles as a function of their diameter for three different wavelengths (405Â nm, 532Â nm, and 671Â nm) from the values of absorbance and their photothermal lens response. We show that for particles of small diameters (<50Â nm) the extinction grows as the cube of the diameter for all three wavelengths. For larger particles the extinction determined from absorbance exhibits a sixth order dependence on the diameters for 532Â nm and 671Â Â nm. This kind of behavior is typical of scattering processes that should dominate for large particles. For 405Â nm the plasmonic resonant absorption dominates over scattering making difficult the observation of the sixth order dependence even for particles larger than 50Â nm. The absorption cross-section measured by the photothermal method does not show the sixth order dependence. It depends on the cube of the particle's diameter for all nanoparticles confirming the scattering free character of this absorption technique and validating the results of the absorbance experiment.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
May Hlaing, Bellsabel Gebear-Eigzabher, Azael Roa, Aristides Marcano, Daniela Radu, Cheng-Yu Lai,