Properties of Ga-interstitial defects inAlxGa1−xNyP1−y

Abstract

A detailed account of the experimental results from optically detected magnetic resonance (ODMR) studies of grown-in defects in (Al)GaNP alloys, prepared by molecular beam epitaxy, is presented. The experimental procedure and an in-depth analysis by a spin Hamiltonian lead to the identification of two ${\mathrm{Ga}}_{i}$ defects (${\mathrm{Ga}}_{i}\text{\ensuremath{-}}A$ and ${\mathrm{Ga}}_{i}\text{\ensuremath{-}}B$). New information on the electronic properties of these defects and the recombination processes leading to the observation of the ODMR signals will be provided. These defects are deep-level defects. In conditions when the defect is directly involved in radiative recombination of the near-infrared photoluminescence band, the energy level of the ${\mathrm{Ga}}_{i}\text{\ensuremath{-}}B$ defect was estimated to be deeper than $\ensuremath{\sim}1.2\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ from either the conduction or valence band edge. In most cases, however, these defects act as nonradiative recombination centers, reducing the efficiency of light emission from the alloys. They can thus undermine the performance of potential photonic devices. High thermal stability is observed for these defects.