Optically detected magnetic resonance (ODMR) studies of molecular beam epitaxial GaNP/GaP structures revealed presence of a P-related complex defect, evident from its resolved hyperfine interaction between an unpaired electronic spin (S=1/2) and a nuclear spin (I=1/2) of a 31P atom. The principal axis of the defect was concluded to be along a ⟨111⟩ crystallographic direction from angular dependence of the ODMR spectrum, restricting the P atom (either a PGa antisite or a Pi interstitial) and its partner in the complex defect to be oriented along this direction. The principal values of the electronic g tensor and hyperfine interaction tensor were determined as: g⊥=2.013, g∥=2.002 and A⊥=130 x 10−4/cm, A∥=330 x 10−4/cm, respectively. The interface nature of the defect was clearly manifested by the absence of the ODMR lines originating from two out of four equivalent ⟨111⟩ orientations. Defect formation was shown to be facilitated by nitrogen ion bombardment under non-equilibrium growth conditions and the defect was thermally stable upon post-growth thermal annealing.

Evidence for a Phosphorus-Related Interfacial Defect Complex at a GaP/GaNP Heterojunction. D.Dagnelund, I.P.Vorona, L.S.Vlasenko, X.J.Wang, A.Utsumi, Y.Furukawa, A.Wakahara, H.Yonezu, I.A.Buyanova, W.M.Chen: Physical Review B, 2010, 81[11], 115334