A host crystal for the rare-earth ion dopants:: Synthesis of pure and Ln-doped urchinlike BiPO4 structure and its photoluminescence

We for the first time report the synthesis of urchinlike BiPO(4) structure composed of nanorods and its photoluminiscence properties. Scanning electron microscopy (SEM) images show urchinlike BiPO(4) structure composed of nanorods. The X-ray powder diffraction (XRD) pattern indicates that the crystal structure of the nanorod is monoclinic. The high-resolution transmission electron microscopy (HRTEM) image and Fast-Fourier-transform (FFT) pattern reveal the single-crystalline nature of the nanorod. The formation mechanism was proposed. BiPO(4) displays strong blue emission. Because of the similarities of the crystal structure and lattice constants and the suitable energy level with the rare-earth phosphate, BiPO(4) is a useful host for rare-earth ions. Ln(3+) is successfully doped in BiPO(4) and an efficient energy transfer from Bi(3+) to Ln(3+) takes place, which makes BiPO(4):Ln (Ln = Eu, Tb, Dy) emit strong luminescence in visible region. BiPO(4):Ln will have promising application in high-performance luminescence devices, etc.