The photoluminescence from a heavily N-doped epilayer, which had been grown by molecular beam epitaxy, was studied. The time decay of the photoluminescence emissions was also measured. A detailed analysis of the photoluminescence data indicated that the deep broad emission comprised 3 distinct recombination processes. Two of these predominated at low powers, and a third was detected at higher excitation powers. The 3 bands were labelled NI, NII and NIII; with corresponding peak energies at 2.54, about 2.58 and 2.65eV. The NI band was accompanied by phonon replicas with an energy of 0.0693eV. It was concluded that the behaviors of these bands were consistent with intra-center recombination, donor-acceptor pair recombination, and electron-acceptor recombination, respectively.

M.Moldovan, S.D.Setzler, T.H.Myers, L.E.Halliburton, N.C.Giles: Applied Physics Letters, 1997, 70[13], 1724-6