Spectroscopy properties and energy level location of Gd2O2S:Pr3+,Ce3+

In this work we propose the study of the spectroscopy properties and the energy level location of Ce3+ and Pr3+ in Gd2O2S, along with the effects of Ce4+ (Ce2O2S2) incorporation in Gd2O2S and Gd2O2S: Pr3+ in order to understand the formation and position of the associated defects energy levels in relation to the band structure of Gd2O2S and Pr3+ energy levels. Ce-, Pr3+-doped and Pr3+, Ce-doped Gd2O2S were prepared by the sulfidization of a basic gadolinium carbonate with S-8 using H-2/N-2 (3.0/97.0%) and air during the firing of the precursor. Samples were analyzed by X-ray diffraction in order to guarantee the formation of the Gd2O2S single phase. Diffuse reflectance spectroscopy and luminescent measurements (emission/excitation) were used to locate Ce3+, Pr3+ and defects energy levels in relation to the band structure of Gd2O2S. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim