Obtaining Efficiently Tunable Red Emission in Ca<sub>3-δ</sub>Ln<sub>δ</sub>WO<sub>6</sub>:Mn<sup>4+</sup> (Ln = La, Gd, Y, Lu, δ = 0.1) Phosphors Derived from Nearly Nonluminescent Ca<sub>3</sub>WO<sub>6</sub>:Mn<sup>4+</sup> via Ionic Substitution Engineering for Solid-State Lighting
Kai Li, Rik Van Deun
Abstract
In this work, a facile ionic substitution strategy was initiated to realize the intense red luminescence in Ca3-δLnδWO6:Mn4+ (δ = 0.1, CLnWO:Mn4+, Ln = La, Gd, Y, Lu,) phosphors evolved from luminescence-ignorable Ca3WO6:Mn4+ (CWO:Mn4+) material, for the first time. It is fascinating that the emission profiles (including the peaks) of these four representative materials are different from each other, which is attributed to the synergistic effect of lattice distortion, Mn4+ transition 2Eg → 4A2g and lattice vibration. The photoluminescence results show that the Ca2.9Gd0.1W0.99O6:0.01Mn4+ (CGdWO:0.01Mn4+) has the best quantum yield and luminescence thermal stability, which makes it be a good candidate for solid-state lighting application. Most significantly, the ionic substitution strategy proposed here will highly enlighten the discovery of series novel Mn4+ doped luminescence materials derived from luminescence-ignorable ones.