The effect of O and Er ion concentrations upon the structural properties of Czochralski-type material was studied by means of secondary ion mass spectroscopy, Rutherford back-scattering spectroscopy, X-ray diffraction, and photoluminescence techniques. In the case of implantation without amorphization, the optimum O concentration was found to reach the maximum Er-related photoluminescence intensity and the formation of structural defects which were detectable using Rutherford back-scattering spectroscopy or X-ray diffraction techniques was prevented. In the case of ion implantation which led to amorphization, it was demonstrated that in spite of the presence of detectable structural defects there were Er implantation doses which permitted an increase in the photoluminescence intensity; as compared with the intensity in non-amorphized layers. The photoluminescence in these layers at 80K was determined by Er-O complexes having cubic symmetry.

H.Ohyama, E.Simoen, C.Claeys, J.Vanhellemont, T.Kudou, Y.Takami, H.Sunaga: Solid State Phenomena, 1997, 57-58, 213-8