Interfacial recombination in GaAlAs–GaAs heterostructures

Photoluminescence time-decay measurements (300 K) are reported for Ga0.5Al0.5As–GaAs double heterostructures over a wide range of GaAs active layer thickness and doping levels. Decay times range from 10 to 650 ns in variously doped GaAs samples. Effects of self-absorption of luminescence and doping level on the decay times are observed for GaAs layer thickness d≳1 μm. For sufficiently thin GaAs layers, interfacial recombination is believed to determine the decay time. The interfacial recombination velocity is observed to vary from Si=300 cm s−1 for p=5×1015 cm−3 heterostructures to Si=500 cm s−1 for p=1.7×1017 cm−3.