Deep red phosphors SrMgAl₁₀O₁₇:Mn⁴⁺, M (M = Li⁺, Na⁺, K⁺, Cl⁻) for warm white light emitting diodes

Abstract

High-saturated red aluminate phosphors SrMgAl₁₀O₁₇ doped with Mn⁴⁺ ions were prepared by solid-state reaction at 1,400 °C. The crystal structure and particle morphology of SrMgAl₁₀O₁₇:Mn⁴⁺ phosphors were investigated by X-ray diffraction, scanning electron microscopy and their photoluminescence were studied by the excitation and emission spectra. The excitation spectrum of samples showed two broad absorption bands ranging from 250 to 480 nm, which indicated that SrMgAl₁₀O₁₇:Mn⁴⁺ could be effectively excited by both near-ultraviolet light and the commercially available blue light of light-emitting diode chips. Simultaneously, the emission spectrum exhibited two sharp peaks (651 and 662 nm) in the deep-red region. It was found that the quenching concentration of Mn⁴⁺ in phosphor was 1.5 mol%. In the end, the effects of doping ions, M (Li⁺, Na⁺, K⁺, Cl⁻) ions, on the luminescent properties of SrMgAl₁₀O₁₇:Mn⁴⁺ were investigated, respectively. The results suggested that all of Li⁺, Na⁺, and Cl⁻ could significantly improve the luminescent properties of SrMgAl₁₀O₁₇:Mn⁴⁺, and the phosphor SrMgAl₁₀O₁₇:Mn⁴⁺, M (M = Li⁺, Na⁺, Cl⁻) was expected to be used as a red phosphor in warm white light emitting diode.