P31electron-nuclear double resonance of thePInantisite in InP:Zn detected via luminescence

Optically detected electron-nuclear double resonance (ODENDOR) has been observed via photoluminescence from the first-neighbor ${}_{}{}^{31}{}_{}{}^{}\mathrm{P}$ shell of the phosphorus antisite in zinc-doped InP. Analysis of the ENDOR data confirms a tetrahedral arrangement of ${}_{}{}^{31}{}_{}{}^{}\mathrm{P}$ nuclei. The hyperfine interaction for each of these nuclei is axial with ‖${\mathit{A}}_{\mathrm{\parallel }}$‖/h=368.0±0.5 MHz and ‖${\mathit{A}}_{\mathrm{\perp }}$‖/h=247.8±0.5 MHz. These parameters are slightly different from those reported by Jeon et al. [Phys. Rev. B 36, 1324 (1987)]. A shift of the ENDOR frequencies correlated with a change in the central nuclear-spin state has also been observed. We have been able to account for this shift with a perturbation treatment in which the electronic spin and central nuclear spin are treated exactly and a neighboring nuclear spin provides the perturbation. The best ENDOR signals are obtained with low optical-excitation-power density (∼0.1 W/${\mathrm{cm}}^2$) and low microwave modulation frequency (17 Hz). These conditions emphasize the contributions to the optically detected magnetic-resonance signal from distant donor-acceptor pairs.