On the Structural, Optical and Electrical Characterization of Zinc Oxide and Aluminium doped Zinc Oxide for Optoelectronic Applications

Adedokun Oluwaseun, Akinlade Johson Adetunji, Busari Debora Ibironke, Adedeji Olufunke Lydia, Ismalia Taiwo Bello

Abstract


Zinc Oxide (ZnO) and Aluminium doped Zinc Oxide (AZO) thin films are deposited on the glass slides by sol-gel spin coating technique. Zinc acetate dehydrate, 2 methoxyethanol, and diethanolamine are respectively used as a precursor, solvent, and stabilizer. Aluminium nitrate nonahydrate was used as the dopant source to obtain the atomic percentage of the dopant of 2%, 4%, 6% and 8%. The structural, optical, and electrical properties of the films were investigated using X-ray Diffraction (XRD), UV-visible spectrophotometry, and a Four-point probe technique respectively. The results from structural analyses show that the films are polycrystalline with a hexagonal wurtzite structure and a preferential orientation alongside the \(c\)-axis. The value obtained for the unit cell \(a=3.020\) A and \(c= 5.108\) A are in line with the reported literature. The transmittance of the films was observed within the visible region of the spectrum and the optical bandgap of the un-doped ZnO was established to be around 4.11 eV. However, the optical bandgap of the AZO films (4 and 6 at %) marginally decreases with doping concentration, which may be ascribed to the shrinkage of band effect due to the increase in carrier concentration. The lowest resistivity of \(3.53\times {10}^{-3}\,\Omega\) cm was observed for the doping concentration of 2% of Al. From the results, it was established that as the doping concentration increases, the thicknesses of the thin films were increased. Likewise, the increase in doping leads to a better uniformly distributed absorption spectra of the deposited AZO thin films.


Keywords


Sol-gel; Spin coating; AZO thin films; Film thickness; Optical properties

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References


S. M. A. Al-dujayli, N. A. Al-Tememee, G. H. Mohamed, B. T. Chiadm, F. J. Kadhim and B. A. Rahman, Morphological and electrical properties of SP deposited Cadmium Sulphide Thin Films, International Journal of Advanced Research in Engineering and Technology 4 (2013), 38 – 49, http://www.iaeme.com/citearticle.asp?Ed=1779&Jtype=IJARET&VType=4&Itype=4

K.-S. An, W. Cho, B. K. Lee, S. S. Lee and C. G. Kim, Atomic layer deposition of undoped and Al-doped ZnO thin films using the Zn alkoxide precursor methylzinc isopropoxide, Journal of Nanoscience and Nanotechnology 8 (2008), 4856 – 4859, DOI: 10.1166/jnn.2008.IC47.

R. Chandramoham, V. Dhanasekaran, S. Ezhilvizhian, T. A. Vijayan, J. Thirumalai, A. J. Peter and T. Mahalingam, Spectral properties of aluminum doped zinc oxide thin films prepared by SILAR method, Journal of Materials Science: Materials in Electronics 23 (2012), 390 – 397, DOI: 10.1007/s10854-011-0439-1.

G. F. Cothian, Absorption Spectrophotometry, 2nd edition, Hilger and Watts Ltd., London, UK (1958).

L. Dominique, L. Julie, C. Ingrid, M. Julie, R. Virginie, P. Nadtha, H. François, F. Ivana and F. Bice, Sintered indium-tin-oxide (ITO) particles: A nero pneutomotoxic entity, Toxicological Sciences 108 (2009), 472 – 481, DOI: 10.1093/toxsci/kfp014.

D. Dragoman and M. Dragoman, Optical Characterization of Solids, Springer-Verlag, Heidelberg (2002).

G. Furlan, D. Nobili, A. M. Sayigh and B. O. Seraphin, Workshop on Materials Science and the Physics of Non-Conventional Energy Sources, World Scientific, Singapore (1989).

J. I. Gittleman, E. Sichel and Y. Arie, Composite semiconductors – selective absorbers of solar energy, Solar Energy Materials 1 (1979), 93 – 104, DOI: 10.1016/0165-1633(79)90060-1.

D. E. Gray, American Institute of Physics Handbook, 3rd edition, McGraw-Hill, New York (1982).

G. Hautier, A. Miglio, G. Cedar, G. M. Rignanese and X. Gonze, Indentification and design principles of low hole effective mass p-type transparent conducting oxides, Nature Communications 4 (2013), 1 – 7, DOI: 10.1038/ncomms3292.

J.-W. Hoon, K.-Y. Chan, J. Krishnasamy, T.-Y. Tou and D. Knipp, Direct current magnetron sputter deposited ZnO thin films, Applied Surface Science 257 (2011), 2508 – 2515, DOI: 10.1016/j.apsusc.2010.10.012.

M. R. Islam and J. Podder, Optical properties of ZnO nano fiber thin films grown by spray pyrolysis of zinc acetate precursor, Crystal Research and Technology 44 (2009), 286 – 2292, DOI: 10.1002/crat.200800326.

J.-P. Kim, S.-A. Leec, J. S. Bae, S.-K. Park, U.-C. Choi and C.-R. Cho, Electric properties and surface characterization of transparent aluminum doped ZnO thin films prepared by pulsed laser deposition, Thin Solid Films 516 (2008), 5223 – 5226, DOI: 10.1016/j.tsf.2007.07.095.

X.-Y. Li, H.-J. Li, Z.-J. Wang, H. Xia, Z.-Y. Xiong, J.-X. Wang and B.-C. Yang, Effect of substrate temperature on the structural and optical properties of ZnO and Al-doped ZnO thin films prepared by dc magnetron sputtering, Optics Communications 282 (2009), 247 – 252, DOI: 10.1016/j.optcom.2008.10.003.

S. Major, S. Kumar, M. Bhatnagar and K. L. Chopra, Effects of hydrogen plasma treatment on transparent conducting oxies, Applied Physics Letters 94 (1986), 394 – 396, DOI: 10.1063/1.97598.

H. Metin, F. Sat, S. Erat and M. Ari, Cadmium sulphide thin films grown by CBD: the effect of thermal annealing on the structural, electrical and optical properties, Journal of Optoelectronics and Advanced Materials 10 (2008), 2622 – 2630, http://hdl.handle.net/20.500.11850/69729.

J. I. Pankove, Optical Processes in Semiconductors, Prentice Hall, New York (1971).

S. Snegal, K. Ravichandran, N. Jabena-Begum, K. Thirumuragan and J. Mater, Enhancement in the electrical and antibacterial properties of sprayed ZnO films by sprayed ZnO films by simultaneous doping Mg and F, Journal of Materials Science: Materials in Electronics 24 (2013), 135 – 141, DOI: 10.1007/s10854-012-0956-6.

Y. W. Sun, J. Gospodyn, P. Kursa, J. Sit, R. G. DeCorby and Y. Y. Tsui, Dense and porous ZnO thin films produced by pulsed laser deposition, Applied Surface Science 248 (2005), 392 – 396, DOI: 10.1016/j.apsusc.2005.03.064.

M. Wang, K. E. Lee, S. H. Hahn, E. J. Kim, J. S. Chung, E. W. Shin and C. Park, Optical and photoluminescent properties of sol-gel Al-doped ZnO thin films, Materials Letters 61 (2007), 1118 – 1121, DOI: 10.1016/j.matlet.2006.06.065.




DOI: http://dx.doi.org/10.26713%2Fjamcnp.v7i1.1368

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