Nanoimprint Lithography Facilitated Plasmonic‐Photonic Coupling for Enhanced Photoconductivity and Photocatalysis

Abstract

Imprint lithography has emerged as a reliable, reproducible, and rapid method for patterning colloidal nanostructures. As a promising alternative to top‐down lithographic approaches, the fabrication of nanodevices has thus become effective and straightforward. In this study, a fusion of interference lithography (IL) and nanosphere imprint lithography on various target substrates ranging from carbon film on transmission electron microscope grid to inorganic and dopable polymer semiconductor is reported. 1D plasmonic photonic crystals are printed with 75% yield on the centimeter scale using colloidal ink and an IL‐produced polydimethylsiloxane stamp. Atomically smooth facet, single‐crystalline, and monodisperse colloidal building blocks of gold (Au) nanoparticles are used to print 1D plasmonic grating on top of a titanium dioxide (TiO2) slab waveguide, producing waveguide‐plasmon polariton modes with superior 10 nm spectral line‐width. Plasmon‐induced hot electrons are confirmed via two‐terminal current measurements with increased photoresponsivity under guiding conditions. The fabricated hybrid structure with Au/TiO2 heterojunction enhances photocatalytic processes like degradation of methyl orange (MO) dye molecules using the generated hot electrons. This simple colloidal printing technique demonstrated on silicon, glass, Au film, and naphthalenediimide polymer thus marks an important milestone for large‐scale implementation in optoelectronic devices.

Advanced Colloidal Sensors Enabled by an Out‐of‐Plane Lattice Resonance

“…[39] In contrast, bottom-up chemical synthesis can produce sharp faceted single-crystalline NPs of high purity and high quality. [40,41] These building blocks can be arranged into defined nanoscale arrays with microscopic dimensions by a range of techniques, including colloidal lithography, [42][43][44] nanoimprint lithography, [39,45,46] capillaryassisted particle assembly (CAPA), [47][48][49] or interface-templated assisted approaches. [50] In this article, we combine soft interference lithography (SIL) [49,51] and CAPA to produce 1D colloidal plasmonic lattices (cPLs).…”

Conductive Materials with Elaborate Micro/Nanostructures for Bioelectronics

“…Nanoimprint lithography (NIL) is another technique to fabricate materials with nanoscale features. [90][91][92] Similarly with the lithography technology mentioned above, pre-prepared masks are fixed on the resist layer to first form patterns, as demonstrated in Figure 3e. [83] Nowadays, NIL has been proven to fabricate nanogaps with parallel grating lines at the scale of around sub-10 nm.…”

Enhanced Figure of Merit via Hybridized Guided‐Mode Resonances in 2D‐Metallic Photonic Crystal Slabs

“…While such higher fill-fractions may not support SLR and result in a broad plasmonic line shape, one can apply the concept of plasmon-photon hybridization [45][46][47][48] to narrow down the resonance linewidth by introducing additional cavity modes [49] as well as guided-mode resonances (GMR). [50,51] Hereby, we report the formation of 2D metallic photonic crystal slabs [52,53] (mPhCs) over a large area through the simple inclusion of a high-indexed waveguide layer [54,55] beneath such a metallic array of higher fill-fraction. The supported hybridized-guided modes provide plasmonic sensing abilities with sharper line widths, therefore improving the FOM in contrast to the plasmonic counterpart (without waveguide layer).…”