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Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters
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Unveiling Long-Lived Hot-Electron Dynamics via Hyperbolic Meta-antennas
Rakesh Dhama1, Mohsin Habib1, Alireza R Rashed1
1Faculty of Engineering and Natural Science, Photonics, Tampere University, 33720 Tampere, Finland.
Nano Letters
|March 3, 2023
Summary
Hyperbolic meta-antennas (HMA) offer spectrally separated scattering and absorption, enhancing hot-electron generation and prolonging carrier dynamics. This advancement optimizes plasmonic applications by enabling simultaneous control over light scattering and absorption for improved performance.
Area of Science:
- Plasmonics and Nanophotonics
- Materials Science
Background:
- Conventional plasmonic nanoantennas suffer from overlapping scattering and absorption bands, limiting simultaneous utilization of their optical properties.
- Hyperbolic meta-antennas (HMA) present an opportunity to decouple these spectral responses.
Purpose of the Study:
- To investigate the potential of HMAs for enhancing hot-electron generation and prolonging hot carrier dynamics.
- To compare the performance of HMAs with conventional nanodisk antennas (NDA) in terms of photoluminescence and hot-electron properties.
Main Methods:
- Fabrication and characterization of hyperbolic meta-antennas (HMA) and nanodisk antennas (NDA).
- Spectroscopic analysis to evaluate scattering and absorption properties.
- Time-resolved measurements to assess hot-electron relaxation dynamics and photoluminescence enhancement.
Main Results:
- HMAs exhibit spectrally separated scattering and absorption bands, unlike NDAs.
- HMAs extend the plasmon-modulated photoluminescence spectrum to longer wavelengths due to their unique scattering properties.
- The tunable absorption band of HMAs effectively controls hot-electron lifetime and enhances excitation efficiency in the near-infrared (NIR) region, broadening spectral utilization compared to NDAs.
Conclusions:
- Hyperbolic meta-antennas provide a versatile platform for engineering plasmon-induced hot carriers by decoupling scattering and absorption resonances.
- The rational design of HMAs with plasmonic and dielectric layers enables optimization of hot-electron generation and relaxation dynamics.
- This work paves the way for advanced plasmonic devices with enhanced functionalities for visible and NIR spectrum applications.
Keywords:
hot carriershyperbolic meta-antennalong-lived hot-electron dynamicsplasmon-modulated photoluminescenceultrafast pump−probe spectroscopyMore Related Videos
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