Near-infrared light absorption and scattering based on a mono-layer of gold nanoparticles
2015 (English)In: Journal of the European Optical Society - Rapid Publications, ISSN 1990-2573, Vol. 10, 15031Article in journal (Refereed) Published
We report fabrication and characterization of large-area ultrathin near-infrared light absorbers and scatterers based on a mono-layer of gold nanoparticles laying on top of a dielectric spacer and an aluminum reflector. The nanoparticles are formed through thermal annealing of an evaporated continuous gold film. Through optimization of initial gold-film thickness, spacer thickness, as well as annealing temperature we obtained samples that exhibit very low (similar to 2%) broadband specular reflectance at near-infrared (NIR) wavelength range. By considering also diffuse reflection, we identify that the low specular reflectance can be due to either relatively high light absorption (similar to 70%) or high light scattering (over 60%), with the latter achieved for samples having relatively sparse gold nanoparticles. Both strong absorption and scattering of NIR light are not inherent properties of the bulk materials used for fabricating the samples. Such composite optical surfaces can potentially be integrated to solar-energy harvesting and LED devices.
Place, publisher, year, edition, pages
2015. Vol. 10, 15031
Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:kth:diva-171018DOI: 10.2971/jeos.2015.15031ISI: 000356758600001OAI: oai:DiVA.org:kth-171018DiVA: diva2:841345
QC 201507132015-07-132015-07-132015-07-13Bibliographically approved