Evidence for a phosphorus-related interfacial defect complex at a GaP/GaNP heterojunction

Abstract

Optically detected magnetic resonance (ODMR) studies of molecular beam epitaxial GaNP/GaP structures reveal 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 P 31 atom. The principal axis of the defect is 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 are determined as: g=2.013, g=2.002, and A=130× 10-4cm-1, A=330× 10-4cm -1, respectively. The interface nature of the defect is clearly manifested by the absence of the ODMR lines originating from two out of four equivalent 111 orientations. Defect formation is shown to be facilitated by nitrogen ion bombardment under nonequilibrium growth conditions and the defect is thermally stable upon post-growth thermal annealing. © 2010 The American Physical Society.