The recombination parameters in heavily carbon-doped GaAs are of considerab
le importance to current bipolar transistor technology. Here, we used time-
resolved photoluminescence and quantum-efficiency techniques in parallel to
measure the very short lifetimes expected at high doping. The samples were
isotype double heterostructures, with the structure Al(0.4)Ga(0.6)As/GaAs/
Al(0.4)Ga(0.6)As, grown by molecular-beam epitaxy. The doping level was var
ied from 5x10(18) to 1x10(20) cm(-3) for the samples described here. For do
ping levels greater than 1x10(19) cm(-3), the lifetime decreased as the inv
erse of the cube of the hole density, indicating that phonon and impurity-a
ssisted Auger processes are dominant. (C) 2001 American Institute of Physic
s.