28 June 2015 to 3 July 2015
Africa/Johannesburg timezone
SAIP2015 Proceeding published on 17 July 2016

Novel zincate phosphors: A new red-emitting phosphors for LED applications

2 Jul 2015, 10:20
20m
Oral Presentation Track C - Photonics Photonics

Speaker

Dr Vijay Kumar (Department of Physics, University of the Free State Bloemfontein 9300)

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

NA

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>

A series of lanthanum calcium zincate (La2CaZnO5) phosphors doped with Eu3+ have been synthesized by the solid state reaction method at different temperatures (700-1300 oC). The reaction temperatures had a significant effect on the surface morphology and luminescent properties of the resultant phosphors. Powder diffraction results showed the formation of a single-phase orthorhombic structure and that the dopant ions do not affect the crystal structure. The scanning and transmission electron microscopic images revealed the irregular morphology of the prepared phosphors consisting out of μm sized diameter particles. The Eu3+ doped phosphors illuminated with ultraviolet light showed the characteristic red luminescence corresponding to the 5D07FJ transitions of Eu3+. The phenomenon of concentration quenching is explained on the basis of ion-ion interaction, electron-phonon coupling and defect to ion energy transfer. Furthermore, the spectral characteristics and the Eu-O ligand behaviour were determined using the Judd-Offelt theory from the spectra. The CIE parameters were calculated using the spectral energy distribution functions and McCamy’s empirical formula. Photometric characterization indicated the suitability of this phosphor for pure red emission in light emitting diode applications.

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

Yes

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Primary author

Dr Vijay Kumar (Department of Physics, University of the Free State Bloemfontein 9300)

Co-authors

Prof. Hendrik Swart (University of the Free State) Dr Sudipta Som (University of the Free State) Dr Vinod Kumar (University of the Free State)

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