Tunable plasmonic lattices of silver nanocrystals

Abstract

Silver nanocrystals are ideal building blocks for plasmonic materials that exhibit a wide range of unique and potentially useful optical phenomena. Individual nanocrystals display distinct optical scattering spectra and can be assembled into hierarchical structures that couple strongly to external electromagnetic fields. This coupling, which is mediated by surface plasmons, depends on their shape and arrangement. Here we demonstrate the bottom-up assembly of polyhedral silver nanocrystals into macroscopic two-dimensional superlattices using the Langmuir-Blodgett technique. Our ability to control interparticle spacing, density, and packing symmetry allows for tunability of the optical response over the entire visible range. This assembly strategy offers a new, practical approach to making novel plasmonic materials for application in spectroscopic sensors, sub-wavelength optics, and integrated devices that utilize field enhancement effects.

Defect tolerance and the effect of structural inhomogeneity in plasmonic DNA-nanoparticle superlattices

“…Moreover, superlattices with higher metal volume fractions exhibit rich optical behavior (8)(9)(10)35). It is likely that the strong, nonlinear plasmonic coupling in these systems will increase the effect of randomness, disorder, and polydispersity on the optical response.…”

“…These efficient interactions with visible light are due to localized surface plasmon resonances (LSPRs), the collective oscillation of conduction electrons (1). Hierarchical arrangements of plasmonic nanoparticles have become the basis for colorimetric sensors (2,3), subdiffraction limited waveguides (4), visible light metamaterials (5), and nanoscale lasing devices (6,7), and the ability to adjust architecture in such materials has led to a wide variety of structures with tunable and unusual optical properties (8)(9)(10)(11)(12). Many of these technologies leverage the scalability and modularity of bottom-up assembly techniques, which use chemically synthesized colloidal nanoparticles as building blocks (13,14).…”

Nanoscale Artificial Plasmonic Lattice in Self‐Assembled Vertically Aligned Nitride–Metal Hybrid Metamaterials

“…Biosensing,1, 2 superlenses,3, 4 subwavelength optics,5, 6, 7 as well as cloaking,8, 9, 10 have been achieved, mostly by artificially designed metallic metamaterials (especially Au, Ag), due to their extraordinary optical properties, such as strong plasmon‐mediated energy confinement, negative refraction, surface plasmon propagation, and zero scattering. More importantly, it has been reported that closely spaced metal nanoparticles show interesting properties such as tunable optical response in the visible range,11 3D photonic crystals with robust photonic bandgaps,12 and theoretical prediction of plasmonics edge states in metallic honeycomb‐like lattices 13. Furthermore, artificially designed metasurfaces, which consist of close packed subwavelength resonators, can modify the scattered wave front at the deep subwavelength scale 14…”

Ambient-stable tetragonal phase in silver nanostructures

“…Controlled synthesis of metal nanoparticles with well-defined compositions, sizes and morphologies has been extensively studied in the last decade [10][11][12][13][14] . However, noble metal nanoparticles with crystalline phases other than the closely packed face-centred cubic (f.c.c.)…”