SAIP2012

Energy transfer from Ce³⁺ to Tb³⁺ in low quartz and amorphous SiO₂ hosts

12 Jul 2012, 17:30

2h

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)

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

Yes

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

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

Presentation Materials

Paper

KG_Tshabalala_et_al__Conf_Series__J_Phys_2012__2.pdf

Peer reviewing

Paper

Accepted on 1 Dec 2014 by Augusto Machatine

Paper files:

• KG_Tshabalala_et_al__Conf_Series__J_Phys_2012_Reviewed.doc