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HL: Fachverband Halbleiterphysik

HL 63: III-V Semiconductors

HL 63.4: Vortrag

Freitag, 26. März 2010, 11:00–11:15, H13

Optically detected cyclotron-resonance in GaAs/Al_0.3Ga_0.7As heterojunction — •Claudia Zens¹, G. Bartsch¹, B.M. Ashkinadze², D.R. Yakovlev¹, and M. Bayer¹ — ¹Experimentelle Physik II, Technische Universität Dortmund, 44227 Dortmund, Germany — ²Solid State Institute, Technion-Israel Institute of Technology, Haifa 3200, Israel

We study the effective electron mass of a high mobility two-dimensional electron gas in a GaAs/Al_0.3Ga_0.7As heterojunction. The effective mass is measured by changes in the photoluminescence, induced by far infrared radiation (FIR) under conditions of the electron cyclotron resonance. Additional illumination above the Al_0.3Ga_0.7As barrier band gap allows flexible control of the carrier concentration, which was tuned in the range from 0.5 to 2·10¹¹cm⁻² in the very same sample. We have found a systematic increase of the electron effective mass with growing carrier concentration, and for higher FIR photon energies. Both trends are in qualitative agreement with the behavior expected due to conduction band nonparabolicity.