Abstract
The evolution of the 2DEG-hole magneto-photoluminescence (PL) with decreasing 2DEG density is studied in a high quality 25 nm-wide modulation-doped GaAs/AlGaAs quantum well in magnetic fields B≤7 T and lattice temperature TL = 1.9 K. The 2DEG density was varied by optical depletion (with He Ne laser illumination) in the range of n2D = (17)×1010 cm−2. As the filling factor decreases below ν = 1, a high-energy PL band (H) emerges; its evolution with B and electron density n2D is studied. At ν0.4, two additional PL lines split off the H-band, and these are assigned to the charged triplet X-t and neutral exciton X0 PL. The evolution from free-hole 2DEG to charged exciton PL with decreasing n2D and with increasing magnetic field (at ν>0.4) is attributed to the appearance of regions containing localized electrons in the photoexcited quantum well. Localization results in simultaneous presence of the free-hole 2DEG PL from the electron puddles (H-band) and the charged exciton PL lines (spin-singlet, X−s and spin-triplet, X−t) from areas containing localized electrons.
Original language | English (US) |
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Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 69 |
Issue number | 11 |
DOIs | |
State | Published - Mar 8 2004 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics