Synthesis and photoluminescence properties of novel red-emitting KBaLu(MoO4)3:Eu3+ phosphors with high thermal stability and high color purity

In this paper, we reported on the photoluminescence properties of novel Eu 3+ -activated KBaLu(MoO 4 ) 3 red-emitting phosphors. Under 395 and 465 nm excitations, the as-prepared samples gave bright sharp red emissions around 592, 615, 655, and 701 nm, corresponding to 5 D 0 → 7 F J (J = 1, 2, 3, and 4) transitions of Eu 3+ ions. The 615 nm red emission due to the 5 D 0 → 7 F 2 transition was dominant in the emission spectra, indicating the Eu 3+ ions occupied non-inversion centrosymmetric sites in KBaLu(MoO 4 ) 3 host lattice. Eu 3+ doping concentration dependent luminescence properties were studied, and the KBaLu(MoO 4 ) 3 :0.8Eu 3+ sample exhibited the strongest emission intensity. The CIE color coordinates and color purity of the optimal KBaLu(MoO 4 ) 3 :0.8Eu 3+ sample were determined to be (0.6655, 0.3311) and 96.7%, respectively. Besides, temperature-dependent emission spectra demonstrated that the KBaLu(MoO 4 ) 3 :0.8Eu 3+ phosphors also exhibited excellent thermal stability (I 423k /I 303k  = 88%) with activation energy △E of 0.204 eV. These obtained results indicated that the newly discovered KBaLu(MoO 4 ) 3 :Eu 3+ red phosphors were promising color converters for application in white light-emitting diodes and display devices.