Near UV-Blue Excitable Green-Emitting Nanocrystalline Oxide

作者：Rodriguez Garcia C E; Perea Lopez N; Hirata G A^*

来源：Advances in Materials Science and Engineering, 2011, 2011: 790517.

DOI：10.1155/2011/790517

Green-emitting Eu-activated powders were produced by a two-stage method consisting of pressure-assisted combustion synthesis and postannealing in ammonia. The as-synthesized powders exhibited a red photoluminescence (PL) peak located at lambda = 616 nm when excited with lambda = 395 nm UV. This emission peak corresponds to the D-5(0) -> F-7(2) transition in Eu3+. After annealing in ammonia, the PL emission changed to an intense broad-band peak centered at lambda = 500 nm, most likely produced by 4f(6)5d(1) -> 4f(7) electronic transitions in Eu2+. This green-emitting phosphor has excitation band in the near UV-blue region (lambda = 300-450 nm). X-ray diffraction analysis reveals mainly the orthorhombic EuAlO3 and Al2O3 phases. Transmission electron microscopy observations showed that the grains are formed by faceted nanocrystals (similar to 4 nm) of polygonal shape. The excellent excitation and emission properties make these powders very promising to be used as phosphors in UV solid-state diodes coupled to activate white-emitting lamps.

• 出版日期2011