9-13 July 2012
Africa/Johannesburg timezone
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A new white light emitting phosphor

Presented by Mr. Samy SHAAT on 12 Jul 2012 from 17:30 to 19:30
Type: Poster Presentation
Session: Poster Session
Track: Track A - Division for Condensed Matter Physics and Materials

Abstract

The objective of this study was to prepare a new aluminates host for rare-earth ions and evaluate it for application in white lighting. CaAl<sub>2</sub>O<sub>4</sub>:Tb<sup>3+</sup>;Eu<sup>3+</sup> nanocrystalline phosphors with good crystallinity were successfully synthesized by a combustion method using urea as fuel and metal nitrates as precursors at a relatively low temperature of 500<sup>o</sup>C. The XRD diffraction patterns showed single monoclinic phase of the CaAl<sub>2</sub>O<sub>4</sub> as referenced to standard JCPDS data files No. 70-134. As confirmed from the scanning electron microscopy (SEM) images, the characteristic platelet-like particles of the combustion method were formed. The diffusion reflectance spectra where recorded from 800-200 nm by using a UV-Vis spectrometer. Photoluminescence (PL) spectroscopy, excitation and emission spectra of CaAl<sub>2</sub>O<sub>4</sub>:Tb<sup>3+</sup>;Eu<sup>3+</sup> were also recorded. A simultaneous emission of blue, green and red PL was observed from CaAl<sub>2</sub>O<sub>4</sub>:Tb<sup>3+</sup>;Eu<sup>3+</sup> phosphor that was excited at 230 nm. The blue and green emissions were respectively attributed to <sup>5</sup>D<sub>3</sub>→<sup>7</sup>F<sub>J(J=0-6)</sub> and <sup>5</sup>D<sub>4</sub>→<sup>7</sup>F<sub>J(J=0-6)</sub> transitions of Tb<sup>3+</sup> while the red emission was attributed to <sup>5</sup>D<sub>0</sub>→<sup>7</sup>F<sub>J(J=0-4)</sub> transitions of Eu<sup>3+</sup>.

Award

Yes

Level

PhD

Supervisor

Prof. Martin Ntwaeaborwa ntwaeab@ufs.ac.za Department of Physics at University of The Free State

Paper

Yes

Place

Location: IT Building
Room:


Primary authors

  • Mr. Samy SHAAT Department of Physics at University of The Free State
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Co-authors

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