The photoluminescence spectra of N-doped samples which had been grown by means of photo-assisted metalorganic chemical vapor deposition at 330 or 350C, and which had N concentrations that ranged from 2.0 x 1017 to 3.0 x 1018/cm3, were measured. The spectra of lightly doped samples exhibited a donor-acceptor pair emission line at 2.696eV; with LO phonon replicas. The spectra of heavily doped samples were dominated by a broad-band donor-acceptor pair emission at longer wavelengths. The deep donor-acceptor emission line, which was considered to be the cause of compensation in N-doped layers that were grown by molecular beam epitaxy, was not observed. The results showed that the numbers of deep donors, related to Se vacancies, that were formed by N doping of samples grown by metalorganic chemical vapor deposition were much lower than those in samples grown by means of molecular beam epitaxy.

Y.Fujita, T.Terada, S.Fujii: Japanese Journal of Applied Physics, 1996, 35[2-4B], L473-5