White-light-emitting diodes based on Ba2+co-doped Sr 3 SiO 5 : Ce3+, Li+phosphor

Abstract

A yellow-orange-emitting Ba²⁺ codoped Sr₃SiO₅: Ce³⁺, Li⁺ phosphor was prepared by high-temperature solid-state reaction. Through transitions of 5d→4f in Ce³⁺, the phosphor showed a very broad and strong yellow emission under near ultraviolet (UV) or blue light excitation. The shifts of the emission band to longer wavelength (yellow-orange) of the Sr₃SiO₅: Ce³⁺, Li⁺ yellow phosphor under the 450-470 nm excitation range have been achieved by adding the element Ba²⁺ in the Sr₃SiO₅ host. White light could be obtained by combining this phosphor with 460nm light-emitting diodes. As the concentrations of the Ba²⁺, Ce³⁺ and Li⁺ ions in the phosphor were 0.35mol, 0.024mol and 0.024mol respectively, the InGaN-based Ba2+ codoped Sr₃SiO₅: Ce³⁺, Li⁺ LED presented intense white emitting and good color rendering of 88.