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O: Fachverband Oberflächenphysik
O 76: Plasmonics and Nanooptics VII
O 76.5: Vortrag
Donnerstag, 17. März 2011, 16:00–16:15, WIL A317
Palladium-based perfect plasmonic absorber in the visible and its application to hydrogen sensing — •Andreas Tittl1, Patrick Mai1, Richard Taubert1, Thomas Weiss1, Na Liu2, and Harald Giessen1 — 14th Physics Institute and Research Center SCoPE, University of Stuttgart, 70569 Stuttgart, Germany — 2Department of Chemistry, University of California, Berkeley, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, 94720, USA
We report on the first experimental realization of a palladium-based perfect plasmonic absorber at visible wavelengths and its application to hydrogen sensing.
Our design utilizes palladium wires on top of a MgF2 spacer layer on a 200 nm thick gold mirror and exhibits an absorbance >99% at the given design wavelength in the red part of the visible spectrum.
Exposure to hydrogen causes a change in the complex refractive index of palladium, resulting in reduced absorption and hence enhanced reflection at the interrogation wavelength[1]. Our sensor has a very fast reaction time of less than 1 second, a recovery time of about 10 seconds, and a lower detection limit of less than 0.5% hydrogen in air.
This pronounced response and background-free operation should enable extremely sensitive optical gas detection schemes down to the ppm range in the future.
[1] N. Liu, et al., Nano Lett. 10, 2342 (2010)