Formation of nonradiative defects in molecular beam epitaxial GaNxAs1-x studied by optically detected magnetic resonance

The formation of two nonradiative defects (i.e., an As-Ga-related complex a nd an unknown deep-level defect with g=2.03) in GaNxAs1-x epilayers and GaA s/GaNxAs1-x multiple-quantum-well structures, grown by molecular beam epita xy, is studied by the optically detected magnetic resonance technique. It i s shown that contributions by these defects in competing carrier recombinat ion strongly vary with the nitrogen composition. An increase in the growth temperature or postgrowth rapid thermal annealing significantly reduces the influence of the nonradiative defects studied, and is accompanied by a rem arkable improvement in the optical properties of the structures. (C) 2001 A merican Institute of Physics.