Identification of an isolated arsenic antisite defect in GaAsBi

Abstract

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, AsGa, with an electron g-factor of 2.03 ± 0.01 and an isotropic hyperfine interaction constant A = (900 ± 20) × 10−4 cm−1. The defect is found to be preferably incorporated during the growth at the lowest growth temperature of 270 °C, but its formation can be suppressed upon increasing growth temperature to 315 °C. The AsGa concentration is also reduced after post-growth rapid thermal annealing at 600 °C.