Optically detected magnetic resonance of native defects inAlxGa1−xAs

The structure and recombination properties of native defects in ${\mathrm{Al}}_{\mathrm{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As have been studied with use of optically detected magnetic resonance (ODMR). Three types of spectra were observed. Extended results are presented for the first type, which has been attributed to Ga interstitials. Spectra taken at different microwave frequencies suggest that alloy disorder affects the line shape. The dependencies on a variety of parameters in molecular-beam and organometallic-vapor-phase epitaxy are explored. Spectral dependence of the ODMR reveals that the +/2+ level of the interstitial is 0.56±0.1 eV above the acceptor level. A brief comparison with other interstitials is presented. The second type of spectrum is sharp with a donorlike g value (1.947±0.003). This ODMR line is attributed to Si donors by comparison to the electron-paramagnetic-resonance work of Bottcher et al. [Phys. Status Solidi B 58, K23 (1973)]. The third type of spectrum has an acceptorlike g value (2.183±0.009 for B parallel to [110]). It may be due to a transition-metal impurity or an Al or Ga antisite.