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Ultrafast spontaneous emission source using plasmonic nanoantennas.

Hoang TB, Akselrod GM, Argyropoulos C, Huang J, Smith DR, Mikkelsen MH - Nat Commun (2015)

Bottom Line: The antennas consist of silver nanocubes coupled to a gold film separated by a thin polymer spacer layer and colloidal core-shell quantum dots, a stable and technologically relevant emitter.We show an increase in the spontaneous emission rate of a factor of 880 and simultaneously a 2,300-fold enhancement in the total fluorescence intensity, which indicates a high radiative quantum efficiency of ∼50%.The nanopatch antenna geometry can be tuned from the visible to the near infrared, providing a promising approach for nanophotonics based on ultrafast spontaneous emission.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Physics, Duke University, Durham, North Carolina 27708, USA. [2] Center for Metamaterials and Integrated Plasmonics, Duke University, Durham, North Carolina 27708, USA.

ABSTRACT
Typical emitters such as molecules, quantum dots and semiconductor quantum wells have slow spontaneous emission with lifetimes of 1-10 ns, creating a mismatch with high-speed nanoscale optoelectronic devices such as light-emitting diodes, single-photon sources and lasers. Here we experimentally demonstrate an ultrafast (<11 ps) yet efficient source of spontaneous emission, corresponding to an emission rate exceeding 90 GHz, using a hybrid structure of single plasmonic nanopatch antennas coupled to colloidal quantum dots. The antennas consist of silver nanocubes coupled to a gold film separated by a thin polymer spacer layer and colloidal core-shell quantum dots, a stable and technologically relevant emitter. We show an increase in the spontaneous emission rate of a factor of 880 and simultaneously a 2,300-fold enhancement in the total fluorescence intensity, which indicates a high radiative quantum efficiency of ∼50%. The nanopatch antenna geometry can be tuned from the visible to the near infrared, providing a promising approach for nanophotonics based on ultrafast spontaneous emission.

No MeSH data available.


Related in: MedlinePlus

QDs coupled to plasmonic NPAs.(a) Three-dimensional illustration of a NPA. The simulated directional radiation pattern from the antenna is shown in red. (b) Cross-sectional schematic of the NPA consisting of a silver nanocube on top of a Au film, separated by a 1 nm polyelectrolyte spacer layer and a sparse layer of ∼6 nm diameter CdSe/ZnS QDs. (c) Transmission electron microscopy image of a silver nanocube and QDs; scale bar, 50 nm. (d,e) Simulated spatial maps of (d) spontaneous emission rate enhancement (Purcell factor) and (e) radiative quantum efficiency for a vertically oriented QD dipole situated in the gap between the nanocube and the Au film.
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f1: QDs coupled to plasmonic NPAs.(a) Three-dimensional illustration of a NPA. The simulated directional radiation pattern from the antenna is shown in red. (b) Cross-sectional schematic of the NPA consisting of a silver nanocube on top of a Au film, separated by a 1 nm polyelectrolyte spacer layer and a sparse layer of ∼6 nm diameter CdSe/ZnS QDs. (c) Transmission electron microscopy image of a silver nanocube and QDs; scale bar, 50 nm. (d,e) Simulated spatial maps of (d) spontaneous emission rate enhancement (Purcell factor) and (e) radiative quantum efficiency for a vertically oriented QD dipole situated in the gap between the nanocube and the Au film.

Mentions: The NPA system consists of a silver nanocube coupled to a metal film, separated by a controlled nanoscale (∼10 nm) dielectric spacer layer and colloidal QDs (Fig. 1a–c). The fundamental plasmonic mode is a Fabry–Pérot resonance resulting from multiple reflections of the waveguide mode beneath the nanocube that propagates within the gap region. The dominant field is normal to the gap with the maximum field enhancement occurring near the nanocube edges and corners3738.


Ultrafast spontaneous emission source using plasmonic nanoantennas.

Hoang TB, Akselrod GM, Argyropoulos C, Huang J, Smith DR, Mikkelsen MH - Nat Commun (2015)

QDs coupled to plasmonic NPAs.(a) Three-dimensional illustration of a NPA. The simulated directional radiation pattern from the antenna is shown in red. (b) Cross-sectional schematic of the NPA consisting of a silver nanocube on top of a Au film, separated by a 1 nm polyelectrolyte spacer layer and a sparse layer of ∼6 nm diameter CdSe/ZnS QDs. (c) Transmission electron microscopy image of a silver nanocube and QDs; scale bar, 50 nm. (d,e) Simulated spatial maps of (d) spontaneous emission rate enhancement (Purcell factor) and (e) radiative quantum efficiency for a vertically oriented QD dipole situated in the gap between the nanocube and the Au film.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4525280&req=5

f1: QDs coupled to plasmonic NPAs.(a) Three-dimensional illustration of a NPA. The simulated directional radiation pattern from the antenna is shown in red. (b) Cross-sectional schematic of the NPA consisting of a silver nanocube on top of a Au film, separated by a 1 nm polyelectrolyte spacer layer and a sparse layer of ∼6 nm diameter CdSe/ZnS QDs. (c) Transmission electron microscopy image of a silver nanocube and QDs; scale bar, 50 nm. (d,e) Simulated spatial maps of (d) spontaneous emission rate enhancement (Purcell factor) and (e) radiative quantum efficiency for a vertically oriented QD dipole situated in the gap between the nanocube and the Au film.
Mentions: The NPA system consists of a silver nanocube coupled to a metal film, separated by a controlled nanoscale (∼10 nm) dielectric spacer layer and colloidal QDs (Fig. 1a–c). The fundamental plasmonic mode is a Fabry–Pérot resonance resulting from multiple reflections of the waveguide mode beneath the nanocube that propagates within the gap region. The dominant field is normal to the gap with the maximum field enhancement occurring near the nanocube edges and corners3738.

Bottom Line: The antennas consist of silver nanocubes coupled to a gold film separated by a thin polymer spacer layer and colloidal core-shell quantum dots, a stable and technologically relevant emitter.We show an increase in the spontaneous emission rate of a factor of 880 and simultaneously a 2,300-fold enhancement in the total fluorescence intensity, which indicates a high radiative quantum efficiency of ∼50%.The nanopatch antenna geometry can be tuned from the visible to the near infrared, providing a promising approach for nanophotonics based on ultrafast spontaneous emission.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Physics, Duke University, Durham, North Carolina 27708, USA. [2] Center for Metamaterials and Integrated Plasmonics, Duke University, Durham, North Carolina 27708, USA.

ABSTRACT
Typical emitters such as molecules, quantum dots and semiconductor quantum wells have slow spontaneous emission with lifetimes of 1-10 ns, creating a mismatch with high-speed nanoscale optoelectronic devices such as light-emitting diodes, single-photon sources and lasers. Here we experimentally demonstrate an ultrafast (<11 ps) yet efficient source of spontaneous emission, corresponding to an emission rate exceeding 90 GHz, using a hybrid structure of single plasmonic nanopatch antennas coupled to colloidal quantum dots. The antennas consist of silver nanocubes coupled to a gold film separated by a thin polymer spacer layer and colloidal core-shell quantum dots, a stable and technologically relevant emitter. We show an increase in the spontaneous emission rate of a factor of 880 and simultaneously a 2,300-fold enhancement in the total fluorescence intensity, which indicates a high radiative quantum efficiency of ∼50%. The nanopatch antenna geometry can be tuned from the visible to the near infrared, providing a promising approach for nanophotonics based on ultrafast spontaneous emission.

No MeSH data available.


Related in: MedlinePlus