Figure 1

(Color online) Typical PL spectra measured at 5 K from the GaNP epitaxial layers grown with and without ion collector, denoted by L021 and L022, respectively. The excitation photon energy is 2.33 eV. The spectra are not calibrated by the instrument response.Reuse & Permissions

Figure 2

(Color online) X-band ODMR spectra obtained at 5 K by monitoring the PL from the GaNP epilayers shown in Fig. 1. The magnetic field is parallel to the $\left[\overline{1}11\right]$ crystallographic direction. The lowest curve displays the difference of the upper two ODMR spectra from the two samples.Reuse & Permissions

Figure 3

(Color online) (a)–(d): ODMR spectra at 5 K from the L022 sample when an external magnetic field was rotated in three crystallographic planes: (110), $\left(\overline{1}10\right)$, and (010), at two different microwave frequencies (i.e., X- and Q-band). The simulated ODMR spectra of the DD1 defect are also displayed, using the spin Hamiltonian parameters given in Table and assuming a Gaussian line shape and linewidth of 10 mT. A background ODMR signal corresponding to that observed in the L021 sample is also included in the simulated ODMR spectra. (e)–(h): Plots of the peak positions (the full circles) of the ODMR lines from the DD1 defect as a function of the angle between the applied magnetic field and the [001] direction in the (110) and $\left(\overline{1}10\right)$ and (010) planes. The solid curves correspond to calculated ODMR positions of the DD1 defect using the spin Hamiltonian parameters given in Table , of which the principal axial axis lies in the $\left(\overline{1}10\right)$ plane (i.e., two possible $⟨111⟩$ orientations). The other two possible defect orientations, of which the axial axis is in the (110) plane, are not experimentally observed (the dashed lines). When the magnetic field was rotated in the (010) plane, see (h), some of the allowed and forbidden defect orientations overlap. In this case, all branches are plotted but only solid lines can be seen.Reuse & Permissions

Figure 4

(Color online) A sketch of tentative models for the DD1 defect complex located at the GaP/GaNP heterointerface. The complex shown here involves (a) a ${\text{P}}_{\text{Ga}}$ antisite or (b) a ${\text{P}}_i$ interstitial, bonded to an unknown defect (or defects) in the nearest-neighbor shell (represented by the small dark ball) along a $⟨111⟩$ direction on the GaNP side of the interface.Reuse & Permissions