Preparation, characterization and luminescence of Sm 3+ or Eu 3+ doped Sr 2CeO 4 by a modified sol-gel method

Abstract

Superfine Sr 2CeO 4:RE 3+ (RE=Eu, Sm) phosphors were synthesized at relatively low temperature by a modified sol-gel method using nitrates as raw materials, ethylenediaminetetraacetic acid (EDTA) as complexing agent. Single phase phosphors could be obtained at calcination temperature above 800 °C and pH value higher than 6.4 of initial solution. The as-prepared powders consisted of uniform crotch-like grains. The preparation process was monitored by thermogravimetric and differential thermal analysis (TG-DTA) and Raman spectra. The obtained products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and photoluminescence. Photoluminescence study indicated that strong energy transfer occurred between Eu 3+/Sm 3+ and host. The Sr 2CeO 4:RE 3+ emission could be tuned from blue to white and red light by varying the concentration of RE 3+. The strong emission and controllable light color are suitable for applications in advanced lighting and displaying fields.