Preparation, characterization and luminescence properties of BiPO4 :Eu nanophosphors

A facile chemical method was employed to prepare fine BiPO4 :Eu(3+) phosphor particles calcined at the same temperature. Introducing lithium greatly affected the morphology of the samples and further affected the luminescence intensity. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectroscopy. The XRD patterns of BiPO4 :Eu(3+) indicated a monoclinic phase. From the fluorescence spectra, the emission transition (5) D0  → (7) F1 is more prominent than the normal red emission transition (5) D0  → (7) F2 . Based on the intensity ratios of (5) D0  → (7) F2 to (5) D0  → (7) F1 in the emission spectra, it can be concluded that introducing Li(+) can improve the symmetry of the crystal lattice and modify the emission intensity. Sharp lines at 395 nm are the strongest of the f-f transitions and match well with near-UV LED chips.