Luminescence Properties of Eu-Doped BaLaAlO<sub>4</sub> Phosphors for Solid State Lighting

Abstract

In this study Barium Lanthanum Aluminate BaLaAlO4 and BaLaAlO4:xEu red phosphors were produced at different x at.% Eu concentration (x = 0,1,3,5 and 7 at.% of Eu) by combustion synthesis method and post-annealing. The X-ray diffraction (XRD) patterns shows that all samples present the orthorhombic phase (JCPDS # 44-0164). Scanning electron microscopy (SEM) shows that the grains size diminished and then increases as a function of Eu-doping concentration addition. Photoluminescence spectra of the samples, under UV excitation, show a maximum strong red emission at lem= 615 nm attributed to the 5D0®7F2 Eu3+ ion transition. The Eu-doped BaLaAlO4 sample that present the highest luminescence intensity was with the x= 1.0 at.% of Eu doping concentration. The quenching in photoluminescence spectra was detected for the Eu doping concentrations of x= 5 and 7 at%, which was ascribed to due to dipole-quadrupole (d-q) interactions. Because the strong red emission of Eu-doped BaLaAlO4 phosphor it could be used UV activated LEDs.