Extremely strong and sharp photoluminescence lines from nitrogen atomic-layer-doped GaAs, AlGaAs and AlGaAs/GaAs single quantum wells

We have performed nitrogen atomic-layer doping into GaAs, AlGaAs, and AlGaAs/GaAs single quantum wells using atomic nitrogen cracked by a hot tungsten filament. While the atomic-layer-doped GaAs layers show a series of sharp and strong photoluminescence lines relating to excitons bound to nitrogen atoms at 8K, atomic-layer-doped AlGaAs layers show several broad nitrogen-related lines. For the atomic-layer-doped single quantum well at the center of the GaAs layer, the quantum well luminescence itself disappears and a dominant and sharp luminescence is observed at a longer wavelength. It is found that the As pressure during the atomic-layer doping greatly affects the luminescence characteristics.