An open aperture z-scan study of Sr2Ceo4 blue phosphor

Abstract

Sr(2)CeO(4) blue phosphor has been prepared by the solid-state reaction method. The X-ray diffraction (XRD) study confirms the structure of the system to be orthorhombic. High resolution electron transmission microscopy reveals that Sr(2)CeO(4) prepared by the solid state reaction method is composed of elongated spherical structures of length similar to 0.2-0.6 mu m and width similar to 90-150 nm. The excitation spectrum shows a broad band which peaks at 275 nm. The emission spectrum shows a broad band which peaks at 467 nm when excited at 275 nm. The emission band is assigned to the energy transfer between the molecular orbital of the ligand and charge transfer (CT) state of the Ce(4+) ion. The Commission International de l'Eclairage (CIE) co-ordinates are x = 0.15, and y = 0.23. The nonlinear absorption behavior of Sr(2)CeO(4) has been investigated using the open aperture z-scan technique. The calculated effective two-photon absorption coefficient shows that the Sr(2)CeO(4) blue phosphor is a promising optical limiting material.