Optical and Dynamical Properties of Chemically Synthesized Gold Nanoplates

Abstract

Single crystal, micrometer-sized nanoplates were formed by reducing Au(III) in the presence of surfactants using a modified polyol protocol. The shapes of the plates range from triangular to hexagonal. The nanoplates have {111} surfaces with an average edge length of 5 ± 2 μm and an average width of 107 ± 30 nm. Scanning electron microscopy (SEM) images reveal that the plates grow through a re-entrant groove created by twinning. The optical properties of the plates were studied by scattered light and transient absorption experiments. The scattered light measurements show that propagating surface plasmon polariton (SPP) modes of the Au nanoplates can be excited when a laser beam is focused at the edge of the nanoplate. We also demonstrate that the direction of propagation of the SPP modes can be controlled through the polarization of the laser beam. The transient absorption traces for single suspended nanoplates show oscillations, which are assigned to thickness vibrations of the plates. The quality factors for the oscillations are smaller than those recently measured for suspended gold nanowires, indicating possible contributions to the vibrational damping from surface bound molecules or from the crystal structure.

Controlled Multichannel Surface Plasmon Polaritons Transmission on Atomic Smooth Silver Triangular Waveguide

“…When the SPPs are excited from the middle of the bottom edge of triangular microplate, the sophisticated polarization‐dependent far‐field emission can be observed on both left‐side and right‐side edges . As shown in Figure a, the emission intensity gradually decreases with the polarization angle varying from 0° to 90° (for more details see Figure S1, Supporting Information).…”

Electron energy losses and cathodoluminescence from complex plasmonic nanostructures: spectra, maps and radiation patterns from a generalized field propagator

“…The gold nanoprism has an edge length of 950 nm and is located on a Si N 3 4 substrate (figure 2(c)). Similar nano-objects have been investigated by EELS, energy-filtered transmission electron microscopy (EFTEM) (Gu et al 2011), two-photon photoluminescence (Viarbitskaya et al 2013) and dark-field microscopy (Major et al 2013). The EELS spectrum is more complex and displays several features at 1, 1.4, 1.6 and 1.8 eV.…”

Morphology-induced redistribution of surface plasmon modes in two-dimensional crystalline gold platelets

“…15 In this context, it has recently been shown that colloidal gold platelets sustain high-order delocalized surface plasmon modes, arising from the two-dimensional (2D) confinement of the electron oscillation. [17][18][19] Indeed, multiple interferences between delocalized SPPs yield optical near-fields that are strongly localized at specific hot spots along the edges of the platelets. 17 These investigations suggest that the control of the spatial and spectral properties of the SP modes and the related SP density of states (SP-DOS) of two-dimensional metallic nanostructures could provide a tool for designing plasmonic devices for optical information processing at the nanoscale.…”