Gap-Plasmon Enhanced Gold Nanoparticle Photoluminescence

Abstract

Gap-plasmon-enhanced gold nanoparticle photoluminescence is studied experimentally at the single-particle level. The photoluminescence spectra of gold nanoparticles on an Al 2 O 3 -coated gold film under both 532 and 633 nm excitation show a clear peak near the measured gap-plasmon resonance wavelength. Comparing the collected emission spectrum with that from a gold reference film under 633 nm excitation, a peak photoluminescence enhancement factor of 28 000 is observed. The spectral shape and absolute magnitude of the enhancement factors for both excitation wavelengths are reproduced using numerical calculations without the use of any free parameters. The photoluminescence enhancement is explained in terms of a gap-mode-enhanced e−h pair generation rate and a wavelength-dependent enhancement of the emission efficiency.

High Order Gap Modes of Film-Coupled Nanospheres

“…[36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52] Due to its geometrical generality, the response of this configuration to electromagnetic wave is an interesting topic which have been studied through several theoretical approaches such 4 as single dipole approximation, 53 static approximation, 54-60 extended Mie method, [61][62][63][64][65] Green's tensor method, 66 rigorous coupled wave analysis (RCWA), 67 plasmon hybridization, [68][69][70][71] transformation optics, 72 and full-wave simulations. [73][74] For the system of film-coupled plasmonic nanoparticles, it contains a well-defined planar structure and can be easily prepared without expensive and time-consuming e-beam based nanofabrication.…”

Anticorrelation of Photoluminescence from Gold Nanoparticle Dimers with Hot-Spot Intensity

“…29−31 Alternatively, the PL from gold nanoparticles with localized plasmons coupling to propagating plasmons of a thin gold film at a fixed distance was investigated. 32,33 …”

Shaping the photoluminescence from gold nanoshells by cavity plasmons in dielectric-metal core-shell resonators

“…This broad emission peak is attributed to the radiative recombination of electrons in the sp band at the Fermi level of gold with holes with the d band below the Fermi level. 13,26 As compared with the planar gold film case, the intensity of the PL generated from the gold nanoshells of the DMCSRs is found to be greatly enhanced, and more interestingly the PL spectrum exhibits multiple emission peaks (red line in Fig. 1(b)).…”

“…For example, the roughened gold surface has been reported to allow for enhancing the PL intensity, 12 where the PL enhancement is gained from the improvement of both excitation and emission efficiency by enhancing the local electric fields associated with the excitations of the LSPRs. Over the past few years, the plasmon-enhanced PL has been extensively investigated in various gold nanostructures such as nanospheres, 13,14 nanorods, 7,14,15 nanoflowers, 16 nanobipyramids, 17 nanodisk arrays, 18 silver nanowire on a dielectric spacer/gold surface, 19 and gold nanobeam-silver nanowire cross-like nanostructure, 20 with the main research focus having been placed on the mechanism of radiative recombination of electrons and holes, the PL intensity maximization, and even controlling the polarization of PL emission. Owing to the strong coupling between the excited electron-hole pairs and the LSPRs, the position and shape of the plasmon-enhanced PL spectra have been demonstrated to be modulated by the LSPRs.…”