Key points are not available for this paper at this time.
Application of the optically detected magnetic resonance (ODMR) technique to donor-acceptor recombination luminescence in donor-doped ZnTe crystals shows the presence of two acceptor centers having noncubic symmetry. One of these centers, labeled Aₓ, has precisely trigonal symmetry C₃. In terms of a spin Hamiltonian for an effective spin S=1/2, its g factors are gₙₙ=2. 664 and gₗₗ=gₘₘ0, where z corresponds to a 〈111〉 direction. The other center, labeled A₌, has mirror symmetry Cₒ, with gₙₙ=2. 540 and gₗₗgₘₘ0. 25, where the z axis is inclined at 6. 7^ to 〈111〉 in a 110 plane. The g factors are interpreted by considering the effect of a low-symmetry crystal field on a J= (3/2) (₈) hole in ZnTe. Hyperfine splittings of magnitude 19010^-4 cm^-1 for Aₓ and 18010^-4 cm^-1 for A₌ are observed in the ODMR spectra and attributed to interactions with three equivalent or nearly equivalent Te nuclei. Center Aₓ is observed in chlorine-doped ZnTe; center A₌ is observed in aluminum-doped ZnTe and is very likely the acceptor called A₂, known by its bound-exciton line at 2. 369 eV. It is proposed that these single-acceptor centers are double-acceptor--single-donor pairs and, more precisely, that the double-acceptor constituent is the zinc vacancy. That is, the trigonal center Aₓ is Vₙ₍₂₋ₓ₄ and the mirror-symmetry center A₌ is Vₙ₍₀₋ₙ₍. If this interpretation is correct, the electronic properties of vacancy centers in ZnTe are remarkably different from those of the well-known Vₙ₍--donor-impurity associates (the ``A centers'') in ZnSe and ZnS. Whereas the latter centers are very deep centers with large pseudo-Jahn-Teller distortions, centers Aₓ and A₌ in ZnTe are of shallow or intermediate depth, retain the full symmetry of the vacancy-impurity complex, and have unquenched orbital angular momentum. Finally, it is suggested that the detection of zinc-vacancy acceptors in donor-doped ZnTe may help one to understand the difficulty of producing n-type material.
Bittebierre et al. (1986) studied this question.