Plasmonic thin films for application to inproved chromogenic windows
2015 (English)In: INERA Conference: Book of Abstracts / [ed] Nesheva, D; Chamati, H; Genova, J; Gesheva, K; Ivanova, T; Szekeres, A, 2015, 20- p., 012003Conference paper, Abstract (Refereed)
Nanocomposites consisting of noble metal nanoparticles in a transparent matrix exhibit plasmonic absorption in the visible wavelength range. On the other hand conducting oxide nanoparticles display a localized plasma absorption in the near infrared. These effects can be exploited in the design of energy-efficient windows in order to obtain improved performance. Electrochromic coatings that switch in the near infrared make use of the modulation of the plasma absorption of oxide nanoparticles due to charge insertion/extraction induced by an external voltage. Thermochromic nanocomposites are predicted to exhibit a much improved energy efficiency, as compared to thermochromics thin films. Plasmonic thermochromics switching in the near infrared has the potential to be significantly larger than in the case of a thin film. Very thin noble metal films are an interesting alternative to conducting oxides as transparent contacts to electrochromic devices. However, in this latter case plasmonic effects are to be avoided rather than exploited.
In order to model and optimize chromogenic devices, a good theoretical understanding of plasmonic effects is necessary. The optical properties of nanocomposites are commonly described by effective medium theories. They describe the effective dielectric function of the composite using as input the dielectric functions of the constituents and their respective volume fractions. However, theoretical modelling by effective medium theories is not straightforward since the effective dielectric function is also sensitively dependent on the actual microgeometry of the composite. These structural effects can be described by the so-called spectral density function. In this paper we describe recent work on three topics related to energy efficient chromogenic window coatings: (1) The performance limits of plasmonic electrochromic coatings, (2) the performance of thermochromics nanocomposites and (3) a study of the optical properties of ultrathin silver films by the spectral density formalism.
Place, publisher, year, edition, pages
2015. 20- p., 012003
, Journal of Physics Conference Series, ISSN 1742-6588 ; 682
Condensed Matter Physics Engineering and Technology
IdentifiersURN: urn:nbn:se:uu:diva-266861DOI: 10.1088/1742-6596/682/1/012003ISI: 000372173400003OAI: oai:DiVA.org:uu-266861DiVA: diva2:868976
Light in nanoscience and nanotechnology, LNN 2015, October 20-22, 2015, Hissar, Bulgaria
FunderSwedish Research Council