Nanoscale surface chemistry directs the tunable assembly of silver octahedra into three two-dimensional plasmonic superlattices

Abstract

A major challenge in nanoparticle self-assembly is programming the large-area organization of a single type of anisotropic nanoparticle into distinct superlattices with tunable packing efficiencies. Here we utilize nanoscale surface chemistry to direct the self-assembly of silver octahedra into three distinct two-dimensional plasmonic superlattices at a liquid/liquid interface. Systematically tuning the surface wettability of silver octahedra leads to a continuous superlattice structural evolution, from close-packed to progressively open structures. Notably, silver octahedra standing on vertices arranged in a square lattice is observed using hydrophobic particles. Simulations reveal that this structural evolution arises from competing interfacial forces between the particles and both liquid phases. Structure-to-function characterizations reveal that the standing octahedra array generates plasmonic ‘hotstrips', leading to nearly 10-fold more efficient surface-enhanced Raman scattering compared with the other more densely packed configurations. The ability to assemble these superlattices on the wafer scale over various platforms further widens their potential applications.

Nanoparticle Superlattices: The Roles of Soft Ligands

“…In addition to NRs, other anisotropic building blocks such as PbS and Cs PbBr 3 nanocubes, cubic and polyhedral CeO 2 nanoparticles, iron oxide truncated nanocubes, Ag octahedra and Au rhombic dodecahedra, octahedra, cubes can be successfully assembled into 1D, 2D, and 3D superlattice using oleic acid, alkylthiols, and cetylpyridinium chloride as capping ligands 102, 103, 104, 105, 106. A chemical approach was utilized to tailor the surface hydrophobicity of Ag octahedral with increasing chain length of alkylthiols, leading to a continuous structural evolution of the wafer‐scale 2D plasmonic superlattices 105.…”

“…A chemical approach was utilized to tailor the surface hydrophobicity of Ag octahedral with increasing chain length of alkylthiols, leading to a continuous structural evolution of the wafer‐scale 2D plasmonic superlattices 105. In another study, the ligand solubility and effective mean size played important roles in determining the resulting superlattice structures of oleate‐covered cubic and polyhedral CeO 2 nanoparticles 103.…”

Signatures of quantized coupling between quantum emitters and localized surface plasmons

“…Hybrid systems composed of metal nanoparticles (MNPs) and quantum emitters (QEs) have drawn intense attention in physics, chemistry, and materials and life sciences [1][2][3][4][5]. By confining light within regions far below the diffraction limit in modes of localized surface plasmons (LSPs), the strong light-matter interaction is realizable in the vicinity of the MNPs [6][7][8][9][10][11][12][13][14].…”

Three‐Dimensional Super‐Branched PdCu Nanoarchitectures Exposed on Controlled Crystal Facets

“…[20][21][22] This approach, however,r equiresc omplicated operations and tends to be rather slow.T o extendt he utility of the self-assembly approach and make it versatile, combining it with the bottom-up approachi sm ore attractive. [20][21][22] This approach, however,r equiresc omplicated operations and tends to be rather slow.T o extendt he utility of the self-assembly approach and make it versatile, combining it with the bottom-up approachi sm ore attractive.…”

“…Nanoscale self-assembly has been employed to manipulate nanocrystals to create two-dimensional (2D) or 3D arrangements( e.g.,s uperlattices) by carefullyt ailoring the interactions between then anocrystals. [20][21][22] This approach, however,r equiresc omplicated operations and tends to be rather slow.T o extendt he utility of the self-assembly approach and make it versatile, combining it with the bottom-up approachi sm ore attractive. Thed irect assembly of the tiny nanocrystals during their growth process is expected to produce unique nanoarchitecturesw ith controlled facets and better catalytic activity and stability.…”