Sharp photoluminescence lines from nitrogen atomic-layer-doped GaAs

We performed nitrogen atomic-layer doping into GaAs grown by molecular beam epitaxy using nitrogen molecules (N2) cracked by a hot tungsten filament. While uniformly nitrogen-doped GaAs layers show relatively weak nitrogen-related photoluminescence lines, nitrogen atomic-layer-doped GaAs layers show a series of sharp and strong photoluminescence lines. The dominant photoluminescence line was observed at 1.4437 eV, where an exciton bound to the nitrogen isotropic traps has the highest binding energy.