Anion/Cation-Controlled Morphology Evolution of Bi1-x PO4:xEu3+ and Enhanced Luminescence Properties

A series of BiPO4:Eu3+ phosphors were hydrothermally synthesized by varying the molar ratio of PO4 (3-)/[Bi3++Eu3+] and the Eu3+ ions concentration in the precursor mixture. X-ray diffraction (XRD), field-emission scanning electronic microscopy (SEM) and photoluminescence (PL) spectra were employed to characterize the structure, morphology and luminescence properties of the as-synthesized phosphors. The XRD results indicate that the crystal structure of the BiPO4:Eu3+ samples are low-temperature monoclinic phase. The SEM observations reveal that the BiPO4:Eu3+ powders morphologies vary from octahedral-like to rod-like with increasing molar ratio of PO4 (3-)/[Bi3++Eu3+]. The PL spectra suggest that the emission intensity of the BiPO4:Eu3+ phosphors significantly enhances when the molar ratio of PO4 (3-)/[Bi3++Eu3+] is greater than 1.0. Therefore, the luminescence properties of BiPO4:Eu3+ phosphors can be improved effectively through controlling the molar ratio of PO4 (3-)/[Bi3++Eu3+] in the precursor mixture, which may provide an important reference for designing new luminescent materials.