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 usi ng BPO4 as the phosphate source. The structure of the prepared powder is id entified as a monoclinic system with a space group of P2(1)/n by X-ray diff raction, which is the same as cerium orthophosphate. X-ray diffractometry ( XRD) spectra indicate that the final product begins to form at about 850 de greesC. The dependence of the brightness of the powder on the concentration of flux and firing temperature is also investigated. The spectral characte ristics of Ce3+, Tb3+ and Gd3+ in lanthanum borophosphate matrix are presen ted, and the energy transfers between different ions are discussed. In comp arison with La(BO3, PO4):Ce, Tb, the addition of Gd3+ causes not only an in crease in Tb3+ emission and a decrease in Ce3+ emission, but also the enhan cement in green component of light. Gd3+ ion acts as the intermediate of en ergy transfer between Ce3+ and Tb3+ ions. (C) 2001 Elsevier Science B.V. Al l rights reserved.