Blue Emitting Phosphors of BaLa2ZnO5 Activated by Bismuth Ions

Abstract

Novel phosphors of BaLa_2–xBi_xZnO₅ exhibiting an emission in the blue region have been synthesized using a vibrating milled solid state reaction with metal oxides. The x-ray diffraction pattern indicates that all of the peaks can be attributed to the single phase. A double exponential decay behavior was observed in BaLa_2–xBi_xZnO₅ phosphor, and the decay time was determined to be 11–25 ms. The magnitude order is very different from that reported in references (microseconds), which led to the efficient interaction between Bi₃₊ ions and BaLa₂ZnO₅ host lattice. The blue emission of the Bi₃₊-doped phosphor has a CIE chromaticity coordinates of x = 0.160, y = 0.021 with a dominant wavelength of the ₃P₁ → ₁S₀ transition at 410 nm under an UV irradiation of 320 nm for the ₁S₀ → ₃P₁ transition and a color purity of about 95%.