4-8 July 2016
Kramer Law building
Africa/Johannesburg timezone
<a href="http://events.saip.org.za/internalPage.py?pageId=10&confId=86">The Proceedings of SAIP2016</a> published on 24 December 2017

Effect of Eu3+ ion concentration on phase transition, site symmetry and quantum efficiency of ZrO2 nanocrystal rods

5 Jul 2016, 16:10
1h 50m
Kramer Law building

Kramer Law building

UCT Middle Campus Cape Town
Board: A.188
Poster Presentation Track A - Division for Physics of Condensed Matter and Materials Poster Session (1)

Speaker

Dr Iorkyaa Ahemen (University of the Free State-Qwaqwa Campus, Private Bag X13, Phuthaditjhaba, 9866, South Africa)

Abstract content <br> &nbsp; (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>

This work report the influence of Eu3+ ion concentration on the photophysical properties of zirconia nanocrytal rods including its intrinsic quantum efficiency (IQE). A simple chemical route was employed in the synthesis of the nanocrystal rods. X-ray diffraction results show mixed phases of monoclinic and tetragonal structures. Phase transition occurred at low (1 mol%) and high (7 and 8 mol%) Eu3+ concentrations. There are three forms of excitations for this phosphor; band edge excitation at 232 nm, charge transfer state transition at 274 and 263 nm, and direct excitation at 362, 395 and 535 nm. Photoluminescence emission for all the doped samples are entirely intraconfigurational Eu3+ emissions and depends both on the site symmetry as well as the Eu3+ concentration. The Eu3+ ions were distributed in both phases especially at high ion concentrations (7 and 8 mol% Eu3+). Two multipolar processes where found to be responsible for the luminescence quenching process in the mixed-structure; the dipole-dipole and the dipole-quadrupole transitions. The intensity parameters ( , ), asymmetry ratio, R0 and the average decay lifetime of the nanocrystals show dependence on concentration and excitation wavelength. High IQE values were obtained at 1, 7 and 8 mol% Eu3+ where the monoclinic phase is dominant. The CIE coordinates values are comparable to existing red phosphors and in combination with the high average IQE of 55% makes this phosphor a good candidate for red emitting phosphor application.

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

N/A

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

No

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

Prof. Dejene B.F.; DejeneBF@ufs.ac.za; University of the Free State-Qwaqwa Campus Phuthaditjhaba, South Africa

Please indicate whether<br>this abstract may be<br>published online<br>(Yes / No)

yes

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

No

Primary author

Dr Iorkyaa Ahemen (University of the Free State-Qwaqwa Campus, Private Bag X13, Phuthaditjhaba, 9866, South Africa)

Co-author

Prof. Francis B. Dejene (University of the Free State-Qwaqwa Campus, Private Bag X13, Phuthaditjhaba, 9866, South Africa)

Presentation Materials

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