Enhancement of the direct optical transition in nanocrystallized GaAsN alloys - art. no. 113312

Using x-ray diffraction. cross-sectional transmission electron microscopy ( XTEM), and infrared absorption techniques, we have investigated the effects of nanocrystallization on the structural and optical properties of GaAs0.9 9N0.01 grown by plasma-enhanced molecular-beam epitaxy. The x-ray diffracti on results of postgrowth annealed samples with a protective Si3N4 cap exhib it significant lattice relaxation. structural inhomogeneity, and apparent n itrogen "loss," indicating the occurrence of phase separation after thermal treatment. High-resolution XTEM confirms the formation of N-enriched GaAsN nanocrystals embedded at the GaAsN/Si3N4 interface, Infrared absorption st udy demonstrates that the annealed sample has a strongly enhanced direct op tical transition.