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The effects of annealing temperatures and chelating agents on the structural and optical properties of ZnO nanoparticles were investigated. The average particle size of ZnO nanoparticles increased with increase of annealing temperatures. The decrease of the full width at half maximum (FWHM) with increasing annealing temperatures inferred increase of particle/grain growth. The grain sizes were also observed to be increased with increase of annealing temperatures. From the absorption spectra of the samples, the absorption was red-shifted and the energy band gap was blue-shifted with increase of annealing temperatures. A sharp UV emission peak was observed and the intensity of this peak increased with annealing temperatures corresponding to the high crystallinity in the samples. At high annealing temperature of 700 ℃, ZnO exhibited a less intense deep level emission. This negligible deep level emission was attributed to the oxygen vacancies created at higher annealing temperatures.


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Annealing effects on the structural and optical properties of ZnO nanoparticles with PVA and CA as chelating agents

Show Author's information A. N. MALLIKA( )A. Ramachandra REDDYK. Venugopal REDDY
Department of Physics, Materials Science Laboratory, National Institute of Technology, Warangal-506004, Telangana, India

Abstract

The effects of annealing temperatures and chelating agents on the structural and optical properties of ZnO nanoparticles were investigated. The average particle size of ZnO nanoparticles increased with increase of annealing temperatures. The decrease of the full width at half maximum (FWHM) with increasing annealing temperatures inferred increase of particle/grain growth. The grain sizes were also observed to be increased with increase of annealing temperatures. From the absorption spectra of the samples, the absorption was red-shifted and the energy band gap was blue-shifted with increase of annealing temperatures. A sharp UV emission peak was observed and the intensity of this peak increased with annealing temperatures corresponding to the high crystallinity in the samples. At high annealing temperature of 700 ℃, ZnO exhibited a less intense deep level emission. This negligible deep level emission was attributed to the oxygen vacancies created at higher annealing temperatures.

Keywords:

ZnO nanostructures, citric acid (CA), polyvinyl alcohol (PVA), chelating agents, scanning electron microscopy (SEM), optical properties
Received: 14 November 2014 Revised: 30 December 2014 Accepted: 24 January 2015 Published: 30 May 2015 Issue date: June 2015
References(26)
[1]
Uthirakumar P, Hong C-H. Effect of annealing temperature and pH on morphology and optical property of highly dispersible ZnO nanoparticles. Mater Charact 2009, 60:1305-1310.
[2]
Lee JB, Kim HJ, Kim SG, et al. Deposition of ZnO thin films by magnetron sputtering for a film bulk acoustic resonator. Thin Solid Films 2003, 435:179-185.
[3]
Minami T, Ida S, Miyata T, et al. Transparent conducting ZnO thin films deposited by vacuum arc plasma evaporation. Thin Solid Films 2003, 445:268-273.
[4]
Seelig EW, Tang B, Yamilov A, et al. Self-assembled 3D photonic crystals from ZnO colloidal spheres. Mater Chem Phys 2003, 80:257-263.
[5]
Hu Y, Chen H-J. Preparation and characterization of nanocrystalline ZnO particles from a hydrothermal process. J Nanopart Res 2008, 10:401-407.
[6]
Dutta S, Chattopadhyay S, Sarkar A, et al. Role of defects in tailoring structural, electrical and optical properties of ZnO. Prog Mater Sci 2009, 54:89-136
[7]
Fang ZB, Yan ZJ, Tan YS, et al. Influence of post-annealing treatment on the structure properties of ZnO films. Appl Surf Sci 2005, 241:303-308.
[8]
Singh RG, Singh F, Kumar V, et al. Growth kinetics of ZnO nanocrystallites: Structural, optical and photoluminescence properties tuned by thermal annealing. Curr Appl Phys 2011, 11:624-630.
[9]
Zak AK, Abrishami ME, Abd MWH, et al. Effects of annealing temperature on some structural and optical properties of ZnO nanoparticles prepared by a modified sol–gel combustion method. Ceram Int 2011, 37:393-398.
[10]
Yang J, Liu X, Wang Y, et al. Effect of annealing temperature on the structure and optical properties of ZnO nanoparticles. J Alloys Compd 2009, 477:632-635.
[11]
Kazemi A, Abadyan M, Ketabi A. Controlled structural and optical properties of ZnO nano-particles. Phys Scr 2010, 82:035801.
[12]
Kuo S-Y, Chen W-C, Cheng C-P. Investigation of annealing-treatment on the optical and electrical properties of sol–gel-derived zinc oxide thin films. Superlattice Microst 2006, 39:162-170.
[13]
Mallika AN, Reddy AR, Babu KS, et al. Synthesis and optical characterization of aluminum doped ZnO nanoparticles. Ceram Int 2014, 40:12171-12177.
[14]
Ravichandran C, Srinivasan G, Lennon C, et al. Influence of post-deposition annealing on the structural, optical and electrical properties of Li and Mg co-doped ZnO thin films deposited by sol–gel technique. Superlattice Microst 2011, 49:527-536.
[15]
Mallika AN, Reddy AR, Babu KS, et al. Structural and photoluminescence properties of Mg substituted ZnO nanoparticles. Opt Mater 2014, 36:879-884.
[16]
Xiong G, Pal U, Serrano JG, et al. Photoluminescence and FTIR study of ZnO nanoparticles: The impurity and defect perspective. Phys Status Solidi c 2006, 3:3577-3581.
[17]
Sujatha Ch., Reddy KV, Babu KS, et al. Effects of heat treatment conditions on the structural and magnetic properties of MgCuZn nano ferrite. Ceram Int 2012, 38:5813-5820.
[18]
Kim SJ, Park SJ, Kim SI. Swelling behavior of interpenetrating polymer network hydro gels composed of poly(vinyl alcohol) and chitosan. Reactive & Functional Polymers 2003, 55:53-59.
[19]
Razavi RS, Loghman-Estarki MR, Farhadi-Khouzani M, et al. Large scale synthesis of zinc oxide nano- and submicro-structures by Pechinis method: Effect of ethylene glycol/citric acid mole ratio on structural and optical properties. Curr Nanosci 2011, 7:807-812.
[20]
Yu H, Yu J, Cheng B, et al. Effects of hydrothermal post-treatment on microstructures and morphology of titanate nanoribbons. J Solid State Chem 2006, 179:349-354.
[21]
Sharma A, Singh BP, Dhar S, et al. Effect of surface groups on the luminescence property of ZnO nanoparticles synthesized by sol–gel route. Surf Sci 2012, 606:L13-L17.
[22]
Singh AK, Viswanath V, Janu VC. Synthesis, effect of capping agents, structural, optical and photoluminescence properties of ZnO nanoparticles. J Lumin 2009, 129:874-878.
[23]
Srinet G, Varshney P, Kumar R, et al. Structural, optical and magnetic properties of Zn1-xCoxO prepared by the sol–gel route. Ceram Int 2013, 39:6077-6085.
[24]
Hsieh PT, Chen YC, Kao KS, et al. The ultraviolet emission mechanism of ZnO thin film fabricated by sol–gel technology. J Eur Ceram Soc 2007, 27:3815-3818.
[25]
Gondal MA, Drmosh QA, Yamani ZH, et al. Synthesis of ZnO2 nanoparticles by laser ablation in liquid and their annealing transformation into ZnO nanoparticles. Appl Surf Sci 2009, 256:298-304.
[26]
Xu J, Shi S, Zhang X, et al. Structural and optical properties of (Al,K)-co-doped ZnO thin films deposited by a sol–gel technique. Mat Sci Semicon Proc 2013, 16:732-737.
Publication history
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Publication history

Received: 14 November 2014
Revised: 30 December 2014
Accepted: 24 January 2015
Published: 30 May 2015
Issue date: June 2015

Copyright

© The author(s) 2015

Acknowledgements

The authors are thankful to the dean of School of Physics, University of Hyderabad, for providing XRD facility. The authors also would like to thank the Sophisticated Analytical Instrument Facility (SAIF) STIC India, Cochin, for the characterization of absorption spectra of the samples.

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