Quenching of Luminescence Emission due to a Transient Bonding State of Donor-Acceptor Pairs at High Excitation Levels in GaAlAs Crystals Doped to Compensation
A new kind of a bound state has been identified at strong external excitation levels in semiconductors with high amphoteric doping, which is formed of a close donor-acceptor molecule and a neighboring second donor and/or acceptor. The recombination behavior of such a bound state is best described by AUGER-type transitions, reason for which this state is called an AUGER molecule. We have determined the existence region of such molecules in silicon-doped Ga1-xAlxAs with respect to excess carrier density and temperature by means of electron-beam excited luminescence spectroscopy at low and medium temperatures. The donor-acceptor pair radiation intensity is affected in a characteristic manner by the existence of the AUGER molecule state at elevated excitation levels and not too low temperatures. A computerized model calculation of corresponding rate coefficients turns out to be in good agreement with experimental results.
A. Zehe et al., "Quenching of Luminescence Emission due to a Transient Bonding State of Donor-Acceptor Pairs at High Excitation Levels in GaAlAs Crystals Doped to Compensation", Materials Science Forum, Vols. 480-481, pp. 457-462, 2005