화학공학소재연구정보센터
Materials Science Forum, Vol.480, 457-461, 2005
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.