It was noted that Czochralski samples which had been implanted with Er exhibited the same cubic crystal field splitting of the 1.54 luminescence as did float-zone material; together with other defect- and O-related Er complexes. The cubic centers exhibited somewhat shorter radiative lifetimes and excitation times. A 100-fold higher luminescence yield of Czochralski samples was therefore attributed to improved incorporation, and to the passivation of recombination centers. The latter conclusion was supported by deep-level transient spectroscopic results, which indicated a complicated annealing behavior.

W.Jantsch, H.Przybylinska, J.Suprun-Belevich, M.Stepikhova, G.Hendorfer, L.Palmetshofer: Materials Science Forum, 1995, 196-201, 609-14