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Determining hot-carrier transport dynamics from terahertz emission
Mohammad Taghinejad1,2, Chenyi Xia2, Martin Hrton3,4
1Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA, USA.
Science (New York, N.Y.)
|October 19, 2023
Summary
Researchers developed a new method to study ultrafast hot-carrier dynamics in plasmonic nanostructures. This technique analyzes terahertz bursts to reveal carrier transport trajectories, crucial for advancing optoelectronics and solar energy.
Area of Science:
- Plasmonics and Nanophotonics
- Ultrafast Dynamics
- Quantum Transport
Background:
- Understanding hot-carrier dynamics is vital for optoelectronics, photochemistry, and solar energy.
- Experimental verification of quantum theories is hindered by ultrashort time and length scales.
Purpose of the Study:
- To present a novel approach for studying plasmonic hot-carrier dynamics.
- To enable experimental verification of ab initio quantum theories for out-of-equilibrium carriers.
Main Methods:
- Analyzing the temporal waveform of coherent terahertz bursts.
- Utilizing designer nano-antennas with broken symmetry.
- Employing polarization- and phase-sensitive detection of terahertz fields.
Main Results:
- Determined an ~11-femtosecond timescale for ballistic carriers ejected from gold antennas.
- This timescale comprises plasmon lifetime and ballistic transport time.
- Direct access to ballistic transport trajectories was achieved.
Conclusions:
- The developed approach facilitates the study of ultrafast carrier dynamics in optically excited nanostructures.
- This method provides new insights into carrier behavior at ultrafast timescales.
- Opens new avenues for research in nanophotonics and energy applications.
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