Abstract
Quantum-dot (QD) materials have shown great promise for THz photoconductive devices. The generation of THz radiation relies on the excitation of highly-mobile carriers with sub-picosecond lifetimes. The band structure of QD materials grown for such THz applications leads to a multitude of energy bands/levels [1], onto which carriers can be excited. Here we show for the first time that the lifetime of carriers excited into the GaAs barriers (λ=800 nm) is up to two orders of magnitude shorter than when these are excited resonantly within the QDs (λ=1245 nm). We also present annealed QD-structures which exhibit faster carrier lifetimes than as-grown ones for most pump conditions, a feature unreported so far. Furthermore, an increase of carrier lifetime with the incident pump power is also unveiled for both annealed and as-grown samples. This study has significant implications in the understanding and optimal use of QD materials for THz generation applications [2].
Original language | English |
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Title of host publication | 2013 Conference on Lasers and Electro-Optics Europe and International Quantum Electronics Conference |
Publisher | IEEE |
ISBN (Electronic) | 978-1-4799-0594-2 |
DOIs | |
Publication status | Published - 2013 |
Event | International Quantum Electronics Conference 2013 - Munich, Germany Duration: 12 May 2013 → 16 May 2013 |
Conference
Conference | International Quantum Electronics Conference 2013 |
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Abbreviated title | IQEC 2013 |
Country/Territory | Germany |
City | Munich |
Period | 12/05/13 → 16/05/13 |
ASJC Scopus subject areas
- Electrical and Electronic Engineering