Effective Red Compensation of Sr₂SiO₄ : Dy³⁺ Phosphor by Codoping Mn²⁺ Ions and Its Energy Transfer

Abstract

Mn 2+ ions codoped Sr 2 SiO 4 : Dy 3+ phosphors were prepared by the solid‐state reaction method using NH 4 Cl as the flux. Their phase compositions, photoluminescence properties, and the energy transfer process were systematically investigated. All Mn/Dy codoped powders were α ′‐Sr 2 SiO 4 . The codoping concentration range of Mn 2+ was ≤4.0 mol% to keep the structure undamaged. The broad red emission of Mn 2+ centered at 647 nm in Sr 2 SiO 4 : Mn, Dy powders, which effectively compensated the red emission of Sr 2 SiO 4 : Dy 3+ phosphor. The CIE chromaticity coordinates dramatically changed from (0.310, 0.340) to (0.332, 0.326) due to the red enhancement via the energy transfer from Dy 3+ to Mn 2+ . This energy transfer is realized by the exchange interaction. But the luminescence quenching of Sr 2 SiO 4 : Dy, Mn phosphor was mainly caused by the electric multipoles interaction. The concentration optimized (Sr 0.96 , Mn 0.02 , Dy 0.02 ) 2 SiO 4 phosphor with high and almost pure white emission has great potential to act as a single‐matrix white phosphor for white LEDs.