Browsing by Author "Green, Sara V."

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    Advances in chromogenic materials and devices
    (2010-03) Granqvist, C. G.; Green, Sara V.; Niklasson, Gunnar A.; Mlyuka, N.R.; Von Kræmer, S.; Georen, Peter
    Chromogenic materials allow the transmittance of visible light and solar energy to be varied under the action of an external stimulus. This paper first discusses buildings related energy savings that can be accomplished by chromogenic technologies, and their beneficial effects on comfort issues. We then summarize recent work on thermochromic VO2-based thin films with particular attention to multi-layers of VO2 and TiO2 and to new VO2:Mg films for which the doping gives significantly lowered absorption of visible light. The final part covers electrochromic materials and devices with foci on coloration efficiency and on durability issues for foil-type constructions based on films of WO3 and NiO.
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    Chromogenics for Sustainable Energy: Some Advances in Thermochromics and Electrochromics
    (2010-10) Granqvist, C. G.; Green, Sara V.; Li, S.-Y.; Mlyuka, N.R.; Niklasson, Gunnar A.; Avendaño, E.
    Chromogenic materials are able to change their optical properties in response to external stimuli such as temperature (in thermochromic materials) and electrical charge insertion (in electrochromic materials). Below we review some recent advances for these types of materials. Specifically we first discuss the limitations of thermochromic VO2 films for energy efficient fenestration and show from calculations that nanocomposites containing VO2 can have superior properties and display high luminous transmittance and large temperature-dependent solar transmittance modulation. Even better results may be found for nanoparticles of VO2:Mg. In the second part of the paper we survey some recent progress for electrochromic devices and show that W oxide films have increased coloration efficiency when some Ni oxide is added. We also present initial results for flexible electrochromic foils produced by roll-to-roll coating and continuous lamination.