9-13 July 2012
Africa/Johannesburg timezone
<a href="http://events.saip.org.za/internalPage.py?pageId=11&confId=14"><font color=#ff0000>SAIP2012 PROCEEDINGS AVAILABLE</font></a>

Energy transfer from Ce<sup>3+</sup> to Tb<sup>3+</sup> in low quartz and amorphous SiO<sub>2</sub> hosts

12 Jul 2012, 17:30
2h
IT Building

IT Building

Poster Presentation Track A - Division for Condensed Matter Physics and Materials Poster Session

Speaker

Mr Kamohelo George Tshabalala (University of the Free State)

Abstract content <br> &nbsp; (Max 300 words)

Low quartz and amorphous Ce3+-Tb3+ co-activated SiO2 phosphors were synthesized by a solution combustion using urea as a fuel. The objective of this study was to compare the efficiency of energy transfer form Ce3+ to Tb3+ in low quartz and amorphous SiO2 hosts. The phosphors were annealed in a reducing atmosphere of 4%H2/96% Ar mixture at an elevated temperature of 1000 °C for 2 hours. This was meant to reduce incidental presence of Ce4+ (non-luminescent) to a fully homogeneous distribution of Ce3+ ions in silica matrix. As confirmed by X-ray diffraction (XRD) data, SiO2 was produced as either low quartz or amorphous phase. The photoluminescence (PL) data showed that green emission of Tb3+ at 543 nm was sensitized by Ce3+, i.e. there was energy transfer from Ce3+ to Tb3+ resulting in an improvement of the green line emission due to the 5D4→7F5 transitions of Tb3+ ions. Possible mechanism of UV down-converted green emission due to energy transfer from Ce3+ to Tb3+ is discussed.

Main supervisor (name and email)<br>and his / her institution

Prof O.M. Ntwaeaborwa, ntwaeab@ufs.ac.za, University of the Free State

Apply to be<br> consider for a student <br> &nbsp; award (Yes / No)?

Yes

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD)?

PhD

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

Yes

Primary author

Mr Kamohelo George Tshabalala (University of the Free State)

Co-authors

Prof. Hendrik Swart (University of the Free State) Prof. Martin Ntwaeaborwa (University of the Free State)

Presentation Materials

Peer reviewing

Paper