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Tunable photoemission from an excitonic antitrap
Katarzyna Kowalik-Seidl1, Xaver P Vögele, Bernhard N Rimpfl
1Fakultät für Physik and Center for NanoScience (CeNS), Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, D-80539 München, Germany. k.kowalik@physik.uni-muenchen.de
Nano Letters
|December 7, 2011
Summary
Photon emission from dipolar excitons is enhanced in an antitrap, not a trap, especially with smaller diameters. This finding allows efficient tuning of excitonic emission energy.
Area of Science:
- Condensed matter physics
- Quantum optics
- Semiconductor nanostructures
Background:
- Dipolar excitons in coupled quantum wells are crucial for optoelectronic devices.
- Electrostatic traps are used to confine excitons, influencing their optical properties.
- Understanding exciton dynamics is key to controlling light emission.
Purpose of the Study:
- To investigate the impact of electrostatic trap configurations on dipolar exciton photon emission.
- To explore the relationship between trap geometry and emission enhancement.
- To leverage exciton dynamics for tunable light emission.
Main Methods:
- Fabrication of lithographically defined electrostatic traps in coupled quantum wells.
- Measurement of photon emission from dipolar excitons under varying trap conditions.
- Theoretical modeling of exciton formation, carrier dynamics, and dipole-dipole interactions.
Main Results:
- Photon emission is unexpectedly enhanced in excitonic antitrap configurations compared to trap configurations.
- This enhancement is more significant for traps with smaller diameters.
- A strong interplay between exciton formation, lateral charge-carrier dynamics, and dipole-dipole interactions governs the observed phenomena.
Conclusions:
- Electrostatic antitrap configurations offer superior control over dipolar exciton emission compared to traps.
- The diameter of the trap plays a critical role in modulating emission intensity.
- This work provides a pathway for efficient, low-intensity tuning of excitonic emission energy.
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