LONG-LIVED PHOTOEXCITED ELECTRON-HOLE PAIRS IN MODULATION-DOPED GAAS ALGAAS QUANTUM-WELLS STUDIED BY INTERSUBBAND SPECTROSCOPY/

Authors
GARINI Y EHRENFREUND E COHEN E RON A LAW KK MERZ JL GOSSARD AC
Citation
Y. Garini et al., LONG-LIVED PHOTOEXCITED ELECTRON-HOLE PAIRS IN MODULATION-DOPED GAAS ALGAAS QUANTUM-WELLS STUDIED BY INTERSUBBAND SPECTROSCOPY/, Solid-state electronics, 37(4-6), 1994, pp. 1199-1202
Citations number
13
Categorie Soggetti
Engineering, Eletrical & Electronic","Physics, Applied","Physics, Condensed Matter
Journal title
Solid-state electronics → ACNP
ISSN journal
00381101
Volume
37
Issue
4-6
Year of publication
1994
Pages
1199 - 1202
Database
ISI
SICI code
0038-1101(1994)37:4-6<1199:LPEPIM>2.0.ZU;2-4
Abstract
We present a study of the e1-e2 intersubband absorption in modulation doped GaAs/Al0.3Ga0.7As MQW's that are photoexcited by interband radia tion. A comprehensive study of the photoinduced absorption (PIA) stren gth as a function of exciting (laser) intensity and modulation frequen cy indicates that only a subgroup of the photoexcited electrons contri bute to the PIA. These electrons are long lived in MQW's with a 2DEG d ensity in the range of 1-3 x 10(10) cm-2. The existence of long lived electrons is explained by a model based on localized, photoexcited hol es, that have a reduced radiative recombination rate with the 2DEG. We calculate this recombination rate and show that it is much longer tha n that of free electrons and holes.