Compensating acceptors and donors in N -doped epilayers that had been grown by molecular beam epitaxy using a N radio-frequency plasma source, were studied by means of photoluminescence and photoluminescence excitation spectroscopy. A deep acceptor and a deep donor, with ionization energies of about 0.170 and 0.088eV, were reported for N -doped layers. These 2 deep centers were attributed to N-clusters such as NSe-Zn-NSe, for the deep acceptor, and NSe-NZn for the deep donor.

Z.Zhu, G.D.Brownlie, G.Horsburgh, P.J.Thompson, S.Y.Wang, K.A.Prior, B.C.Cavenett: Journal of Crystal Growth, 1996, 159, 248-51