Interferometric scattering of single plasmonic nanoparticle cluster assembled in nanostructured template

We reveal the significance of plasmonic nanoparticle’s (NP) shape and its surface morphology en route to an efficient self-assembled plasmonic nanoparticle cluster. A simplified model is simulated in the form of free-space dimer and trimer nanostructures (NPs in the shape of a sphere, cube, and disk). A ~200% to ~125% rise in near-field strength (gap mode enhancement) is observed for spherical NPs in comparison with cubical NPs (from 2 nm to 8 nm gap sizes). Full-width three-quarter maximum reveals better broad-spectral optical performance in a range of ~100 nm (dimer) and ~170 nm (trimer) from spherical NPs as compared to a cube (~60 nm for dimer and trimer). These excellent properties for sphere-based nanostructures are merited from its dipole mode characteristics.

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Designing an Efficient Self-Assembled Plasmonic Nanostructures from Spherical Shaped Nanoparticles

10.20944/preprints202109.0225.v1 ◽

2021 ◽

Author(s):

Vasanthan Devaraj ◽

Jong-Min Lee ◽

Ye-ji Kim ◽

Hyuk Jeong ◽

Jin-Woo Oh

Keyword(s):

Near Field ◽

Simplified Model ◽

Plasmonic Nanostructures ◽

Dipole Mode ◽

Plasmonic Nanoparticle ◽

Mode Characteristics ◽

Cluster A ◽

Self Assembled ◽

Nanoparticle Cluster ◽

Gap Mode

We reveal the significance of plasmonic nanoparticle’s (NP) shape and its surface morphology en route to an efficient self-assembled plasmonic nanoparticle cluster. A simplified model is simulated in the form of free-space dimer and trimer nanostructures (NPs in shape of sphere, cube, and disk). A ~ 200 % to ~ 125% raise in near field strength (gap mode enhancement) is observed for spherical NPs in comparison with cubical NPs (from 2 nm to 8 nm gap sizes). Full-width three-quarter maximum reveals better broad-spectral optical performance in a range of ~ 100 nm (dimer) and ~ 170 nm (trimer) from spherical NPs as compared to a cube (~ 60 nm for dimer and trimer). These excellent properties for sphere-based nanostructures are merited from its dipole mode characteristics.

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Size-dependent emission of a dipole coupled to a metal nanoparticle

MRS Advances ◽

10.1557/adv.2020.429 ◽

2020 ◽

Vol 5 (62) ◽

pp. 3315-3325

Author(s):

Viktoriia Savchuk ◽

Arthur R. Knize ◽

Pavlo Pinchuk ◽

Anatoliy O. Pinchuk

Keyword(s):

Numerical Analysis ◽

Quantum Yield ◽

Electric Dipole ◽

Incident Radiation ◽

Metal Nanoparticle ◽

Plasmonic Nanoparticle ◽

Size Dependent ◽

Emission Enhancement ◽

Electric Dipoles

AbstractWe present a systematic numerical analysis of the quantum yield of an electric dipole coupled to a plasmonic nanoparticle. We observe that the yield is highly dependent on the distance between the electric dipole and the nanoparticle, the size and permittivity of the nanoparticle, and the wavelength of the incident radiation. Our results indicate that enhancement of the quantum yield is only possible for electric dipoles coupled to a nanoparticle with a radius of 20 nm or larger. As the size of the nanoparticle is increased, emission enhancement occurs at wavelengths dependent on the coupling distance.

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Strong coupling of a plasmonic nanoparticle to a semiconductor nanowire

Nanophotonics ◽

10.1515/nanoph-2021-0214 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Yingying Jin ◽

Liu Yang ◽

Chenxinyu Pan ◽

Zhangxing Shi ◽

Bowen Cui ◽

...

Keyword(s):

Strong Coupling ◽

Coupled System ◽

Resonance Wavelength ◽

Transverse Magnetic ◽

Spectral Shift ◽

Au Nanoparticle ◽

Localized Surface Plasmon ◽

Nanowire Diameter ◽

Plasmonic Nanoparticle ◽

Au Nanosphere

Abstract By placing a single Au nanoparticle on the surface of a cadmium sulfide (CdS) nanowire, we demonstrate strong coupling of localized surface plasmon resonance (LSPR) modes in the nanoparticle and whispering gallery modes (WGMs) in the nanowire. For a 50-nm-diameter Au-nanosphere particle, strong coupling occurs when the nanowire diameter is between 300 and 600 nm, with a mode splitting up to 80 meV. Using a temperature-induced spectral shift of the resonance wavelength, we also observe the anticrossing behavior in the strongly coupled system. In addition, since the Au nanosphere has spherical symmetry, the supported LSPR mode can be selectively coupled with transverse electric (TE) and transverse magnetic (TM) WGMs in the nanowire. The ultracompact strong-coupling system shown here may provide a versatile platform for studying hybrid “photon–plasmon” nanolasers, nonlinear optical devices, and nanosensors.

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Effects of gap thickness and emitter location on the photoluminescence enhancement of monolayer MoS2 in a plasmonic nanoparticle-film coupled system

Nanophotonics ◽

10.1515/nanoph-2020-0178 ◽

2020 ◽

Vol 9 (7) ◽

pp. 2097-2105

Author(s):

Xiaozhuo Qi ◽

Tsz Wing Lo ◽

Di Liu ◽

Lantian Feng ◽

Yang Chen ◽

...

Keyword(s):

Near Field ◽

Central Area ◽

Field Enhancement ◽

Coupled System ◽

Film Structure ◽

Plasmonic Nanoparticle ◽

Emitter Location ◽

Radiation Properties ◽

Radiation Enhancement ◽

Quantum Emitters

AbstractPlasmonic nanocavities comprised of metal film-coupled nanoparticles have emerged as a versatile nanophotonic platform benefiting from their ultrasmall mode volume and large Purcell factors. In the weak-coupling regime, the particle-film gap thickness affects the photoluminescence (PL) of quantum emitters sandwiched therein. Here, we investigated the Purcell effect-enhanced PL of monolayer MoS2 inserted in the gap of a gold nanoparticle (AuNP)–alumina (Al2O3)–gold film (Au Film) structure. Under confocal illumination by a 532 nm CW laser, we observed a 7-fold PL peak intensity enhancement for the cavity-sandwiched MoS2 at an optimal Al2O3 thickness of 5 nm, corresponding to a local PL enhancement of ∼350 by normalizing the actual illumination area to the cavity’s effective near-field enhancement area. Full-wave simulations reveal a counterintuitive fact that radiation enhancement comes from the non-central area of the cavity rather than the cavity center. By scanning an electric dipole across the nanocavity, we obtained an average radiation enhancement factor of about 65 for an Al2O3 spacer thickness of 4 nm, agreeing well with the experimental thickness and indicating further PL enhancement optimization. Our results indicate the importance of configuration optimization, emitter location and excitation condition when using such plasmonic nanocavities to modulate the radiation properties of quantum emitters.

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