Structural and luminescent properties of blue-emitting Sr2CeO4 phosphors by high-energy ball milling method

Abstract

Sr2CeO4 phosphors were prepared by means of a high-energy ball milling method and sintered at various temperatures. The X-ray diffraction patterns of the as-prepared phosphors confirmed their orthorhombic structure. The FE-SEM images revealed that the Sr2CeO4 phosphors were composed of spherical particles with diameters of less than 2µm. The excitation spectra showed a broad band which peaks at 299nm and has a shoulder at 349nm due to the t1g–f and t1u–f charge transfer states of Ce4+ ions. The emission spectra exhibited a broad blue-emission band with a maximum at 478nm that originates from the Ce4+–O2− charge transfer transition resulting from the interaction of Ce4+ ion with the neighboring oxide ions. The highest photoluminescence emission intensity was observed when the powder was sintered at 1100°C. The results of this study indicate that Sr2CeO4 phosphors have the potential to be used in applications such as white light-emitting diodes (WLEDs) and optical display systems.