New lines in the photoluminescence spectrum of lightly Be-doped material were reported. The low-temperature photoluminescence spectrum of lightly-doped samples was dominated by a transition at 3.385eV; with first and second LO phonon replicas. Power-resolved photoluminescence measurements showed that a peak at 3.385eV narrowed in width, and shifted to higher energies, with increasing excitation intensity. The transition was therefore attributed to donor-to-acceptor recombination which involved a Be acceptor with an optical ionization energy of between 0.09 and 0.1eV. This was much shallower than the acceptor level (0.25eV) that was introduced by Mg doping. Increased doping resulted in quenching of the band-edge luminescence, and in the appearance of a broad transition that was centered around 2.4eV. This was attributed to a complex which involved Be. All luminescence was quenched upon increasing the doping level even further.

D.J.Dewsnip, A.V.Andrianov, I.Harrison, J.W.Orton, D.E.Lacklison, G.B.Ren, S.E.Hooper, T.S.Cheng, C.T.Foxon: Semiconductor Science and Technology, 1998, 13[5], 500-4