Photoluminescence and cathodoluminescence properties of a novel CaLaGa 3O 7:Dy 3+ phosphor

Abstract

A single host white emitting phosphor, CaLaGa 3O 7:Dy 3+, was synthesized by chemical co-precipitation. Field emission scanning electron microscopy, X-ray diffraction, laser particle size analysis, and photoluminescence and cathodoluminescence spectra were used to investigate the structural and optical properties of the phosphor. The phosphor particles were composed of microspheres with a slight tendency to agglomerate, and an average diameter was of about 1.0 μm. The Dy 3+ ions acted as luminescent centers, and substituted La 3+ ions in the single crystal lattice of CaLaGa 3O 7 where they were located in Cs sites. Under excitation with ultraviolet light and a low voltage electron beam, the CaLaGa 3O 7:Dy 3+ phosphor exhibited the characteristic emission of Dy 3+ ( 4F 9/2- 6H 15/2 and 4F 9/2- 6H 13/2 transitions) with intense yellow emission at about 573 nm. The chromaticity coordinates for the phosphor were in the white region. The relevant luminescence mechanisms of the phosphor are investigated. This phosphor may be applied in both field emission displays and white light-emitting diodes. © 2011 Science China Press and Springer-Verlag Berlin Heidelberg.