A key challenge for the development of active plasmonic nanodevices is the lack of materials with fully controllable plasmonic properties. In this work, we demonstrate that a plasmonic resonance in top-down nanofabricated yttrium antennas can be completely and reversibly turned on and off using hydrogen exposure. We fabricate arrays of yttrium nanorods and optically observe in extinction spectra the hydrogen-induced phase transition between the metallic yttrium dihydride and the insulating trihydride. Whereas the yttrium dihydride nanostructures exhibit a pronounced particle plasmon resonance, the transition to yttrium trihydride leads to a complete vanishing of the resonant behavior. The plasmonic resonance in the dihydride state can be tuned over a wide wavelength range by simply varying the size of the nanostructures. Furthermore, we develop an analytical diffusion model to explain the temporal behaviour of the hydrogen loading and unloading process observed in our experiments and gain information about the thermodynamics of our device. Thus, our nanorod system serves as a versatile basic building block for active plasmonic devices ranging from switchable perfect absorbers to active local heating control elements.

Date Published: 17 August 2014
PDF: 11 pages
Proc. SPIE 9163, Plasmonics: Metallic Nanostructures and Their Optical Properties XII, 916305 (17 August 2014); doi: 10.1117/12.2061364

Published in SPIE Proceedings Vol. 9163:
Plasmonics: Metallic Nanostructures and Their Optical Properties XII
Allan D. Boardman, Editor(s)