Au Double Nanopillars with Nanogap for Plasmonic Sensor

Abstract

We propose a simple, precise, and wafer-scale fabrication technique for Au double nanopillar (DNP) arrays with nanogaps of several tens of nanometers. An Au DNP was simply constructed by alternately laminating thin layers of Au and polymer on a template and selectively removing the thin layers. This DNP array was expected to exhibit a specific plasmonic property induced by its narrow gap. When measuring the refractive index sensitivity (RIS), Au DNP arrays with 33 nm gaps exhibited a high RIS of 1075 nm RIU(-1) and showed a higher sensor figure of merit than the alternative structures, which did not have a nanogap structure but had almost the same surface area. This indicated that the enhanced plasmon electromagnetic field induced by the nanogap structure improved sensor performance. Our fabrication technique and the optical properties of the nanogap structure will provide useful information for developing new plasmonic applications with nanogap structures.

Infrared Perfect Ultra-narrow Band Absorber as Plasmonic Sensor

“…7d, the sensitivity (S) of the sensor is 2400 nm/RIU, while FWHMs can be narrower than 0.5 nm. Therefore, the FOM of the plasmonic sensor can reach 4800, which is improved remarkably compared to any previously reported plasmonic metamaterial structure [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37].…”

“…Thus, it is very meaningful to design an ultra-high FOM refractive index sensor with a simple structure. Unfortunately, the previously reported plasmonic sensors based on metamaterial structure generally have a relatively low FOM <600 [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39], which will severely limit their further development and application. Shen designed a gold mushroom array structure with a narrow FWHM of 10 nm and a high FOM of 108 [22].…”

Omnidirectional excitation of sidewall gap-plasmons in a hybrid gold-nanoparticle/aluminum-nanopore structure

“…Gap-plasmon resonances of metallic nanostructures are rapidly gaining interest due to their extremely high electromagnetic field enhancement which is advantageous in several practical applications including molecular sensing, [1][2][3][4][5] photovoltaics, 6,7 photocatalysis, 8,9 and nanolasers. 10,11 Metallic nanoparticles on a metallic film (known as the particle-on-mirror geometry) represent an attractive gap plasmon supporting structure because they can be prepared with low-cost methods and exhibit a resonance wavelength that can be controlled reliably by modifying the thickness of a spacer layer.…”

Large‐Area Gold/Parylene Plasmonic Nanostructures Fabricated by Direct Nanocutting

“…However, those techniques suffer from their serial nature, resulting in high costs and poor throughput. For plasmonic and metamaterial applications, in particular for photovoltaic [ 12 ] and sensing devices, [ 13 ] a precise and cost-effi cient fabrication of nanostructures on large areas is essential in order to emerge from the experimental stage into real-life applications. In contrast, replication-based techniques enable surface patterning over large areas.…”