Ultrafast carrier dynamics of surfactant-mediated-grown InAs/GaAs quantum-dot structures designed for THz applications

TY - GEN

T1 - Ultrafast carrier dynamics of surfactant-mediated-grown InAs/GaAs quantum-dot structures designed for THz applications

AU - Daghestani, N. S.

AU - Alduraibi, M.

AU - Piwonski, T.

AU - Ochalski, T.

AU - Huyet, G.

AU - Missous, M.

AU - Ackemann, T.

AU - Cataluna, M. A.

PY - 2013

Y1 - 2013

N2 - 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 (?=800 nm) is up to two orders of magnitude shorter than when these are excited resonantly within the QDs (?=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].

AB - 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 (?=800 nm) is up to two orders of magnitude shorter than when these are excited resonantly within the QDs (?=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].

U2 - 10.1109/CLEOE-IQEC.2013.6801116

DO - 10.1109/CLEOE-IQEC.2013.6801116

M3 - Conference contribution

SN - 9781479905935

BT - 2013 Conference on Lasers and Electro-Optics Europe & International Quantum Electronics Conference

PB - IEEE

CY - Piscataway, NJ.

T2 - 2013 Conference on Lasers and Electro-Optics Europe & International Quantum Electronics Conference

Y2 - 12 May 2013 through 16 May 2013

ER -