Red-luminescence enhancement of ZrO2-based phosphor by codoping Eu3+ and M5+ (M = Nb, Ta)

Red emission of monoclinic Zr(1-2x)EuxMxO2 (M = Nb, Ta; x = 0.05) was enhanced by the M addition, about five times higher than Zr0.95Eu0.05O2 excited by 395 nm or 469 nm at room temperature. The corresponding quantum yield improves 2-4 times, achieving similar to 13%. The luminescence enhancement is attributed to that the codoped Eu3+ and M5+ ions result in the seven-coordinated Eu3+ activators with the low symmetry C-1, compared with the eight-coordinated high symmetric (D-2d) Eu3+ ions coexisted with oxygen vacancies in Zr(1-x)EuxO2. The thin film of Zr0.90Eu0.05Nb0.05O2, deposited by radio frequency magnetron sputtering method, also shows intensely red emission. (C) 2012 Elsevier B.V. All rights reserved.Materials Science, MultidisciplinaryOpticsSCI(E)EI0ARTICLE81353-13563