9-13 July 2012
Africa/Johannesburg timezone
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Comparative study of luminescence properties of Eu2+, Dy3+ and Tm3+ co-doped CaAl2O4 powder phosphors

Presented by Dr. Mokhotjwa Simon DHLAMINI on 12 Jul 2012 from 11:00 to 11:20
Type: Oral Presentation
Session: DCMPM1
Track: Track A - Division for Condensed Matter Physics and Materials


Preparation of Eu<sup>2+</sup>, Dy<sup>3+</sup> and Tm<sup>3+</sup> ions co-doped CaAl2O4 phosphor powders by combustion method is reported. The morphology and particle size, and crystal structure of the CaAl<sub>2</sub>O<sub>4</sub> host were confirmed by field emission scanning electron microscopy (FESEM) and X-ray diffractometer (XRD), respectively. Ultraviolet, visible (UV/VIS) and cathodoluminescence measurements were carried out in order to investigate the optical properties of the powder phosphors. Blue emission at 440 nm from Eu2+ excited with He-Cd laser for all systems was measured. No emission from Dy<sup>3+</sup> and Tm<sup>3+</sup> ions were measured. Excitation with Auger electron spectroscopy (AES) showed emission from Tm<sup>3+</sup> (at 458 nm and 470 nm) and Dy<sup>3+</sup> (at 571 nm and 477 nm) dominating the emission from Eu<sup>2+</sup> ions. The emission intensities of the different systems were compared. Different excitation energies (wavelengths) using the spectrophotometer equipped with xenon lamp were used to excite the powders and the observed change in the shape of the emission spectra is reported. Key words: Cathodoluminescence, Photoluminescence, Combustion, Blue emission





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