Enhancement of Luminescence Properties by Sr2+ Substituting Ba2+ in Red-Emitting Phosphors: Ba1-ySryLa2-xZnO5:xEu (x=0-1, y=0-0.7)

Ba(1-x)Sr(y)La(2-x)ZnO(5):xEu (x = 0-1, y = 0-0.7) was prepared by the vibrating milled solid-state reaction, and the photoluminescence properties were investigated. The results show that the optimum emission intensity is at y = 0.5 for serial BaLa(2-x)ZnO(5):xEu phosphors under near-UV light excitation (394 run) and the CIE chromaticity coordinate is located at (0.624, 0.376). Furthermore, Sr(2+) doping for serial Ba(1-y)Sr(y)La(1.5)Eu(0.5)ZnO(5) (y = 0-0.7) phosphors were also investigated; photoluminescence properties indicated that increasing Sr(2+) content enhances not only the emission intensity ratio of (5)D(0) -> (7)F(2) transition (red emission) to (5)D(0) -> (7)F(1) transition (orange emission) but also the emission intensity of (5)D0 -> (7)F(2) transition. The color purity enhancement results from the relatively lower symmetry environment around Eu(3+) ions. The Ba(0.3)Sr(0.7)La(1.5)Eu(0.5)ZnO(5) phosphors have optimal integrated emission intensity, which is 62% larger than the integrated emission intensity of BaLa(1.5)Eu(0.5)ZnO(5) phosphors, and the CIE chromaticity coordinate (v, y) of Ba(0.3)Sr(0.7)La(1.5)Eu(0.5)ZnO(5) phosphor is (0.633, 0.367) under near-UV light excitation. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3190531] All rights reserved.