Abstract
A comprehensive experimental study of the photoluminescence (PL) spectral evolution under a magnetic field applied perpendicularly to a high-mobility two-dimensional electron gas (2DEG), is performed on modulation-doped heterojunctions at . The abrupt transfer of the free exciton to hole-2DEG PL occurring at integer and fractional filling factors is analyzed in a phenomenological model, wherein free excitons photogenerated in the GaAs layer dissociate into a 2D electron and 3D hole near the 2D-electron channel. Such magnetic field induced exciton-(2De-h) transitions are able to explain the remarkable strong PL anomalies in single hetrojunctions as compared to those observed in modulation-doped quantum wells.
- Received 24 March 2005
DOI:https://doi.org/10.1103/PhysRevB.72.075332
©2005 American Physical Society