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
IT Building

IT Building

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


Mr Kamohelo George Tshabalala (University of the Free State)

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

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

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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.

Primary author

Mr Kamohelo George Tshabalala (University of the Free State)


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

Presentation Materials

Peer reviewing