Preparation and photoluminescence of the Ce-, Tb- and Gd-doped lanthanum borophosphate phosphor

Cerium-, terbium- and gadolinium-doped lanthanum borophosphate [La(BO3, PO4):Ce, Tb, Gd] phosphors have been prepared by a single-step calcination using BPO4 as the phosphate source. The structure of the prepared powder is identified as a monoclinic system with a space group of P21/n by X-ray diffraction, which is the same as cerium orthophosphate. X-ray diffractometry (XRD) spectra indicate that the final product begins to form at about 850°C. The dependence of the brightness of the powder on the concentration of flux and firing temperature is also investigated. The spectral characteristics of Ce3+, Tb3+ and Gd3+ in lanthanum borophosphate matrix are presented, and the energy transfers between different ions are discussed. In comparison with La(BO3, PO4):Ce, Tb, the addition of Gd3+ causes not only an increase in Tb3+ emission and a decrease in Ce3+ emission, but also the enhancement in green component of light. Gd3+ ion acts as the intermediate of energy transfer between Ce3+ and Tb3+ ions.