Optically detected magnetic resonance of shallow donors in GaAs

The observation, via optically detected magnetic resonance, of shallow donors in GaAs is reported. A resonance having ‖g‖=0.43±0.01 was observed as a change in the long-wavelength photoluminescence from samples doped with approximately ${10}^{16}$ ${\mathrm{cm}}^{\mathrm{-}3}$ Te and approximately 4×${10}^{16}$ ${\mathrm{cm}}^{\mathrm{-}3}$ Cr. The large resonance linewidth of 930 mT is attributed to exchange interactions with randomly distributed recombination partners.