Internal Transitions of Neutral and Charged Magneto-Excitons in GaAs/AlGaAs Quantum Wells

• Published in: physica status solidi (b) Vol. 210; no. 2; pp. 341 - 346
• Main Authors: Nickel, H.A., Herold, G.S., Yeo, T., Kioseoglou, G., Jiang, Z.X., McCombe, B.D., Petrou, A., Broido, D., Schaff, W.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.12.1998; WILEY‐VCH Verlag
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/(SICI)1521-3951(199812)210:2<341::AID-PSSB341>3.0.CO;2-8

We have used Optically Detected Resonance (ODR) spectroscopy to probe the electronic properties of undoped and barrier‐doped GaAs/Al0.3Ga0.7As multiple‐quantum‐well (MQW) samples with well widths between 12.5 and 20 nm in magnetic fields up to 15 T at low temperatures. The simultaneous observation of electron and hole CR along with several internal transitions of neutral excitons (IETs) verifies the symmetry‐related energy differences of the internal transitions to differences between electron and hole CR. The observed degeneracy of the 1s → 2p+ IET from the two radiative magneto‐excitons is due to the very small electron g‐factor. ODR measurements on 20 nm wide MQWs (not‐intentionally‐ and barrier‐doped) exhibit transitions of the negatively charged excitonic complex.