Near UV-Blue Excitable Green-Emitting Nanocrystalline Oxide. (19th May 2011)

• Record Type: Journal Article
• Authors: Rodríguez-García, C. E.; Perea-López, N.; Hirata, G. A.
• Other Names: Majewski Peter Academic Editor.
• Is Part Of: Advances in materials science and engineering. Volume 2011(2011)
• Publication Date: 2011-05-19
• Subjects: Materials science -- Periodicals; Materials science; Periodicals; 620.11
• DOI: 10.1155/2011/790517
• Languages: English
• ISSNs: 1687-8434

Abstract

Abstract : 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 atλ = 616 nm when excited withλ = 395 nm UV. This emission peak corresponds to the 5 D0 → 7 F2 transition in Eu 3+ . After annealing in ammonia, the PL emission changed to an intense broad-band peak centered atλ = 500 nm, most likely produced by 4f 6 5d 1 →4f 7 electronic transitions in Eu 2+ . This green-emitting phosphor has excitation band in the near UV-blue region (λ = 300 –450 nm). X-ray diffraction analysis reveals mainly the orthorhombic EuAlO3 and Al2 O3 phases. Transmission electron microscopy observations showed that the grains are formed by faceted nanocrystals (~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.