EPR, thermo and photoluminescence properties of ZnO nanopowders

Reddy, Jagannatha A and Kokila, MK and Nagabhushana, H and Rao, JL and Shivakumara, C and Nagabhushana, BM and Chakradhar, RPS (2011) EPR, thermo and photoluminescence properties of ZnO nanopowders. In: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 81 (1). pp. 59-63.

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Abstract

Nanocrystalline ZnO powders have been synthesized by a low temperature solution combustion method. The photoluminescence (PL) spectrum of as-formed and heat treated ZnO shows strong violet (402, 421, 437, 485 nm) and weak green (520 nm) emission peaks respectively. The PL intensities of defect related emission bands decrease with calcinations temperature indicating the decrease of Zn(i) and V(o)(+) caused by the chemisorptions of oxygen. The results are correlated with the electron paramagnetic resonance (EPR) studies. Thermoluminescence (TL) glow curves of gamma irradiated ZnO nanoparticles exhibit a single broad glow peak at similar to 343 degrees C. This can be attributed to the recombination of charge carriers released from the surface states associated with oxygen defects, mainly interstitial oxygen ion centers. The trapping parameters of ZnO irradiated with various gamma-doses are calculated using peak shape method. It is observed that the glow peak intensity increases with increase of gamma dose without changing glow curve shape. These two characteristic properties such as TL intensity increases with gamma dose and simple glow curve structure is an indication that the synthesized ZnO nanoparticles might be used as good TL dosimeter for high temperature application. (C) 2011 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	ZnO;Photoluminescence;Thermoluminescence;Electron paramagnetic resonance
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	07 Dec 2011 06:43
Last Modified:	07 Dec 2011 06:43
URI:	http://eprints.iisc.ac.in/id/eprint/42535

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