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

Role of defects in the emission of undoped and doped ZnO thin film prepared by pulsed laser deposition

2 Jul 2015, 14:40
20m
Oral Presentation Track A - Division for Physics of Condensed Matter and Materials DPCMM

Speaker

Dr Vinod Kumar (Department of Physics, University of the Free state, Bloemfontein, ZA-9300)

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

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

Prof. H.C. Swart
University of the Free State
Bloemfontein, 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>

Undoped and doped zinc oxide (ZnO) thin films were grown by the pulsed laser deposition (PLD) technique on silicon (Si) substrate at different growth conditions. According to the x-ray diffraction patterns, all the ZnO films were oriented along the (002) plane. This is in line with the characteristics of the hexagonal wurtzite ZnO structure where the c-axis is perpendicular to the substrate plane. Generally, ZnO have two emissions, the near-band edge emission and the deep level emission. The strong near-band edge emission at room temperature is due to free exciton recombination while the visible light emission is ascribed to the structural defects such as zinc vacancy (Vzn), oxygen vacancy (Vo), interstitial zinc (Zni), interstitial oxygen (Oi) and antisite oxygen (Ozn). The photoluminescence spectra of terbium doped ZnO (ZnO:Tb3+) thin films were characterized by three different types of transitions, the one was due to exciton recombination emission, the second was due to defect level emission and the third was due to the Tb3+ f-f transitions. The formation of different kind of defects in the ZnO was confirmed by X-ray photoelectron spectroscopy results. For the emission due to the Tb3+ ions, a major green emission peak at 543 nm and a few minor peaks at 489 and 622 nm were detected. These peaks represent the 5D4-7F5, 5D4-7F6, and 5D4-7F3 transitions of Tb3+, respectively. These ZnO thin films can be used as a suitable future light emitting material applications.

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

no

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

Yes

Primary author

Dr Vinod Kumar (Department of Physics, University of the Free state, Bloemfontein, ZA-9300)

Co-authors

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

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