Optically detected electron-paramagnetic-resonance investigations of the substitutional oxygen defect in gallium arsenide

The substitutional oxygen defect in GaAs has been investigated with magnetic circular dichroism of the absorption, optically detected electron paramagnetic resonance, and optically detected electron-nuclear double resonance (ODENDOR). The ODENDOR spectra can be explained with an oxygen atom occupying an As site displaced from a regular lattice position along a [100] direction. The superhyperfine interactions and spin densities for several As and Ga neighbors have been determined. The experiments support a model in which the oxygen atom is bonded to two Ga atoms and which shows similarities to the A center in silicon. [S0163-1829(97)03339-0].