Identification of an isolated arsenic antisite defect in GaAsBi

Optically detected magnetic resonance and photoluminescence spectroscopy are employed to study grown-in defects in GaAs0.985Bi0.015 epilayers grown by molecular beam epitaxy. The dominant paramagnetic defect is identified as an isolated arsenic antisite, As-Ga, with an electron g-factor of 2.03 +/- 0.01 and an isotropic hyperfine interaction constant A (900 +/- 620) x 10(-4) cm(-1). The defect is found to be preferably incorporated during the growth at the lowest growth temperature of 270 degrees C, but its formation can be suppressed upon increasing growth temperature to 315 degrees C. The As-Ga concentration is also reduced after post-growth rapid thermal annealing at 600 degrees C. (C) 2014 AIP Publishing LLC.