Effect of SiO2 introduction on luminescence properties of LuAG:Mn2+ phosphors

Mn2+ doped LuAG phosphors with different contents of Si4+ ions were synthesized via the solid-state reaction method and the effects of Si4+ doping on the crystal structure and luminescence properties of phosphors were studied. XRD patterns of all phosphors exhibit a pure phase but with different extents of deviations. Owing to the 4T1→6A1 transition of Mn2+, the LuAG:Mn2+,Si4+ phosphors exhibit a broad emission band with an emission peak at 582 nm. Moreover, the introduction of Si4+ not only improves the emission intensity but also induces a red-shift with the emission peak from 582 to 612 nm and the spectra broadening with the full width at half maximum value from 64 to 74 nm, which results from the decrease of bond length between O2− anions and Mn2+ cations and the re-absorption of Mn2+-Mn2+ pairs. Suitable content of Si4+ replacement can weaken thermal quenching of Mn2+. Thus, via regulating the content of Si, the Mn2+, Si4+ co-doped LuAG phosphor with low correlated color temperature is a candidate for warm wLEDs.