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Sensitivity engineering in direct contact palladium-gold nano-sandwich hydrogen sensors
Publikationstyp
Journal Article
Date Issued
2015-10-15
Sprache
English
Author(s)
Strohfeldt, Nikolai
Zhao, Jun
Tittl, Andreas
Giessen, Harald
Journal
Volume
5
Issue
11
Start Page
2525
End Page
2535
Citation
Optical Materials Express 5 (11): 2525-2535 (2015)
Publisher DOI
Scopus ID
Publisher
Optical Society of America, OSA
In recent years, plasmonic hydrogen sensing schemes using complex hybrid Pd@Au nanostructures have attracted significant attention. However, so far, most studies have focused on investigating the sensing performance of nanosensor geometries where the constituent materials are laterally coupled. In contrast to such planar hybrid systems, which often require complex multi-step fabrication approaches, sensing devices where the materials are stacked directly on top of each other can be fabricated in a single lithography step, enabling straightforward high-throughput processing. Here, we demonstrate a novel hydrogen sensing scheme which incorporates complex hybrid plasmonic nanostructures consisting of stacked gold and palladium nanodisks. In particular, we study the influence of stacking order and geometry, experimentally and numerically, to find an optimal arrangement for a hydrogen sensor device. With an optimized sensing geometry - a stack of gold as lower and palladium as upper disk - we obtain spectral shifts as large as 30 nm at 4 vol.% H<inf>2</inf>, which is a strong improvement compared to previous indirect sensing designs. Our samples yield large absorption and scattering signals and are fabricated by low-cost hole-mask colloidal lithography and therefore yield sample sizes over areas of 1 cm<sup>2</sup>.
DDC Class
600: Technology