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Hot-carrier dynamics in InAs/AlAsSb multiple-quantum wells
Herath P Piyathilaka1, Rishmali Sooriyagoda1, Hamidreza Esmaielpour2
1Department of Physics and Astronomy, West Virginia University, Morgantown, WV, 26506-6315, USA.
Scientific Reports
|May 19, 2021
Summary
Investigating photoexcited carrier dynamics in InAs/AlAsSb quantum wells reveals long-lived states and a metastable state. Temperature and excitation energy influence carrier lifetimes, offering insights for advanced optoelectronic devices.
Area of Science:
- Semiconductor Physics
- Quantum Optics
- Materials Science
Background:
- Understanding photoexcited carrier dynamics is crucial for optimizing semiconductor devices.
- Type-II InAs/AlAsSb multiple-quantum wells (MQWs) exhibit unique electronic properties.
- The influence of excitation photon energy and lattice temperature on carrier behavior requires detailed investigation.
Purpose of the Study:
- To investigate the photoexcited carrier dynamics in a type-II InAs/AlAsSb MQW sample.
- To analyze the dependence of carrier dynamics on excitation photon energy and lattice temperature.
- To elucidate the mechanisms governing carrier lifetimes and metastable states for potential applications.
Main Methods:
- Time-resolved measurements using near-infrared pump and terahertz probe pulses.
- Varying excitation photon energies near and above the band gap.
- Conducting experiments at different lattice temperatures.
Main Results:
- Transient terahertz absorption exhibits multi-rise, multi-decay behavior, indicating long-lived states and a metastable state.
- Excess photon energy facilitates transitions from the metastable state to long-lived states.
- Long-lived state decay times increase with temperature due to enhanced phonon interactions and stabilization of hot carriers.
Conclusions:
- Photoexcited carrier dynamics in InAs/AlAsSb MQWs are complex, involving energy transfer between valence and defect states.
- The observed long-lived and metastable states are influenced by excitation energy and temperature.
- Findings suggest pathways for prolonging hot carrier lifetimes, crucial for optoelectronic device advancements.
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