Luminescence enhancement of LiSrPO₄:Eu²⁺ phosphor by Mg²⁺ ion addition

Abstract

Mg-doped LiSrPO₄:Eu²⁺ (Li(Sr, Mg)PO4:Eu²⁺) phosphors, in which some Sr²⁺ ions were replaced by Mg²⁺ ions, were prepared using a conventional solid-state reaction method. The crystal structure of the phosphors was hexagonal, which is the high-temperature phase of LiSrPO₄, even though synthesis was carried out at a relatively low temperature of 900 °C. Fluorescence could be efficiently excited in the 220–400 nm ultraviolet region, and bright blue emission was produced with a peak at 448 nm. The emission intensity was higher than that for LiSrPO₄:Eu²⁺ without Mg doping, and a lower Eu content (1 mol%) was required in order to reach the maximum intensity. These results indicate that the blue-emitting Li(Sr, Mg)PO₄:Eu²⁺ phosphor is a promising candidate for phosphor-conversion white Light Emitting Diodes.

Keywords:

• Optical materials
• inorganic compounds
• chemical synthesis
• phosphors