Plasmonic nanoparticles by laser dewetting of thin metallic films
Author(s)
Advisor
Aydınlı, AtillaDate
2013Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
In this work, formation of metal nanoparticles via laser induced dewetting and their
plasmonic properties have been investigated. The effects of metal film, substrate type,
laser power density and dwell time on dewetting phenomenon were analyzed. Silver and
gold thin films were fabricated with thermal evaporation on various substrates. Next,
they were characterized by the ellipsometry, UV-VIS spectroscopy and atomic force
microscopy (AFM) as the characteristic of the thin film affects dewetting. Samples were
then processed by a cw argon laser. Varying the dwell time and power density, Ag and
Au nanoparticles with different morphology were obtained. At the final stages of
dewetting, nanoparticles attained spherical shapes. Particle size distribution and length
scale analysis were performed using the images obtained from scanning electron
microscope (SEM). Using these results, relations between the average particle size and
film thickness, as well as the relation between length scale and film thickness were
obtained to verify the occurrence of dewetting. Substrate and film type were observed to
affect the particle morphology and particle size. Moreover, plasmonic resonance effect
of Ag and Au nanoparticles were observed via the optical absorbance measurements.
Multilayered metallic nanoparticles and embedded nanoparticles were fabricated and
were found to display plasmonic properties.