Crystal structure and luminescence characterizations of Eu 3+ -doped Sr 2 GaTaO 6 phosphors with high color purity for w -LEDs

In order to acquire a red light-emitting component for an efficient w -LEDs device, we synthesized a series of Eu 3+ -doped Sr 2 GaTaO 6 (SGT) phosphors using a traditional high-temperature solid-phase technique. The results of UV diffuse reflectance proved that the SGT host possesses a broad optical energy bandgap ( E gap ) of 4.47 eV (calculated value). The relevant characteristic spectra were also tested. By monitoring the emission at 612 nm, the excitation peak at 466 nm matches the blue light region (460–470 nm) of the popular blue LED chips on the market. The photoluminescence (PL) spectra of SGT: Eu 3+ phosphors at room temperature consisting of four obvious PL bands ( 5 D 0 → 7 F 1 , 5 D 0 → 7 F 2 , 5 D 0 → 7 F 3 , and 5 D 0 → 7 F 4 ) in the visible range. And the PL properties are necessarily analyzed by fluorescence decay curves. And it exhibits a decent photoluminescence quantum yield (39.88%). Moreover, the color purity and the ∆E of the SGT: 0.2Eu 3+ sample are 96.5% and 0.29 eV, respectively, demonstrating that the ∆E of SGT: Eu 3+ phosphor is superior to other reported Eu 3+ -doped materials for w -LEDs applications. The results manifest that the Eu 3+ doped SGT phosphors can be outstanding candidates for w -LEDs applications with high color purity and activation energy.