Sensitivity engineering in direct contact palladium-gold nano-sandwich hydrogen sensors [Invited]

Abstract

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 diskwe obtain spectral shifts as large as 30 nm at 4 vol.% H 2 , 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 2 .

Full Color Generation Using Silver Tandem Nanodisks

“…57 The low-energy asymmetric mode produces a virtual current loop due to retardation effects; therefore, a magnetic moment is generated and the magnetic field is enhanced between the two metal disks. This has been used in surface-enhanced Raman scattering (SERS), 58−60 sensors, 61,62 high Purcell factors, 63 negative refractive indexes, 64 and so on. Particularly, trapezoidal sandwich structures can further enhance the magnetic field and exhibit Fano resonances.…”

Watching in situ the hydrogen diffusion dynamics in magnesium on the nanoscale

“…Switchable optical and nanophotonic systems are of ever-increasing interest not only from a fundamental (1)(2)(3)(4)(5) but also from an applied standpoint (6)(7)(8)(9)(10)(11)(12)(13). Materials with prominent metal to insulator phase transitions (14,15) are prime candidates for such systems and have thus been investigated in great detail.…”

Active plasmonic nanoantenna: an emerging toolbox from photonics to neuroscience

“…The resultant crystal and electronic band structure alterations lead to drastic changes in the optical properties of PNAs, thereby causing remarkably strong LSPR modulations. Metal hydrides have attracted significant interest in realization of optical hydrogen sensors [180][181][182], switchable mirrors [183,184], chirality switching [185], and dynamic color displays [169]. Palladium (Pd), magnesium (Mg), zirconium (Zr), titanium (Ti), and vanadium (V) are some of the most studied metal hydride materials.…”