title: High-Density 2D Homo- and Hetero- Plasmonic Dimers with Universal Sub-10-nm Gaps.
abstract: Fabrication of high-density plasmonic dimers on a large (wafer) scale is crucial for applications in surface-enhanced spectroscopy, bio- and molecular sensing, and optoelectronics. Here, we present an experimental approach based on nanoimprint lithography and shadow evaporation that allows for the fabrication of high-density, large-scale homo- (Au-Au and Ag-Ag) and hetero- (Au-Ag) dimer substrates with precise and consistent sub-10-nm gaps. We performed scanning electron, scanning transmission electron, and atomic force microscopy studies along with a complete electron energy-loss spectroscopy (EELS) characterization. We observed distinct plasmonic modes on these dimers, which are well interpreted by finite-difference time-domain (FDTD) and plasmon hybridization calculations.
authors.forename: Mingliang
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Physics and Astronomy, Laboratory for Nanophotonics, Rice University , Houston, Texas, United States.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Large
authors.forename: Ai Leen
authors.initials: AL
authors.lastname: Koh
authors.affiliation: Department of Physics and Astronomy, Laboratory for Nanophotonics, Rice University , Houston, Texas, United States.
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Physics and Astronomy, Laboratory for Nanophotonics, Rice University , Houston, Texas, United States.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Manjavacas
authors.forename: Robert
authors.initials: R
authors.lastname: Sinclair
authors.affiliation: Department of Physics and Astronomy, Laboratory for Nanophotonics, Rice University , Houston, Texas, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Nordlander
authors.forename: Shan X
authors.initials: SX
authors.lastname: Wang
mesh_terms: D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure*; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure*
keywords: electron energy-loss spectroscopy (EELS); finite-difference time-domain (FDTD); nanoimprint lithography; plasmon hybridization; plasmonic dimers; shadow evaporation