Layers which had been grown by metalorganic chemical deposition were implanted with N, and then annealed in a N atmosphere. Photoluminescence spectra revealed an acceptor-bound excitonic emission line, and donor-to-acceptor pair recombination emission, which indicated that N atoms were activated as shallow acceptors. An additional donor-to-acceptor emission was observed at 462nm. This had also been observed in N-doped material which had been prepared by molecular beam epitaxy. It was proposed that Se vacancy generation accelerated the occupation of N atoms at Se sites, and that excess vacancy generation led to the formation of deep donor complexes.

A.Kamata, T.Moriyama: Applied Physics Letters, 1995, 67[12], 1751-3