Photoluminescence properties of novel BaLuBO:Eu red emitting phosphors with high color purity for near-UV excited white light emitting diodes.

A series of new red-emitting BaLu Eu LaBO (0.1 ≤ ≤ 1.0) phosphors were synthesized the high-temperature solid-state reaction method. The phase formation of the as-synthesized BaLuEuLaBO phosphor was confirmed by powder X-ray diffraction analysis. It was found that La doping resulted in the reduction of LuBO impurities and thus pure phase BaLuBO was realised. The morphology of BaLuEuLaBO phosphors was studied by field emission scanning electron microscopy (FE-SEM). As a function of Eu concentration the photoluminescence spectra and decay lifetimes were investigated in detail. Under excitation at 396 nm, a dominant red emission peak located at 616 nm (D → F) indicated that Eu ions mainly occupied low symmetry sites with a non-inversion center in BaLuEuLaBO. The optimal Eu ion concentration was found to be = 0.5 and the critical distance of Eu was determined to be 6.55 Å. In addition, the concentration quenching takes place dipole-dipole interactions. The phosphors exhibited good CIE (Commission International de I'Eclairage) color coordinates ( = 0.643, = 0.356) situated in the red region and a high color purity of 97.8%. Furthermore, the internal quantum efficiency and the thermal stability of BaLuEuLaBO phosphors were also investigated systematically. The results suggest that BaLuEuLaBO may be a potential red phosphor for white light-emitting diodes.