OPTICAL PROPERTIES OF Al:ZnO THIN FILM DEPOSITED BY DIFFERENT SOL-GEL TECHNIQUES: ULTRASONIC SPRAY PYROLYSIS AND DIP-COATING

Year 2016, Volume: 3 Issue: 3, 175 - 184, 08.01.2017

Ebru Gungor Tayyar Gungor

https://doi.org/10.18596/jotcsa.02215

Abstract

Undoped and Al-doped ZnO polycrystalline thin films have been fabricated on glass substrates by using a computer-controlled dip coating (DC) and ultrasonic spray pyrolysis (USP) systems. The film deposition parameters of DC process were optimized for the samples. In this technique, the substrate was exposed to temperature gradient using a tube furnace. In the study, the other solvent-based technique was conventional USP. The zinc salt and Al salt concentrations in the solution were kept constant as 0.1 M and 2% of Zn salt’s molarity, respectively. The optical properties were compared for the films deposited two different techniques. The optical transmission of Al:ZnO/Glass/Al:ZnO sample dip coated and  the optical transmission of Al:ZnO/Glass sample ultrasonically sprayed were determined higher than 80% in the visible and near infrared region. Experimental optical transmittance spectra of the films in the forms of FilmA/Glass/FilmA and FilmA/glass were used to determine the optical constants. It was observed that the optical band gaps of Al doped ZnO films onto glass substrate were increases with increase of Al content and the absorption edge shifted to the shorter wavelength (blue shift) compared with the undoped ZnO thin film.

References

• http://en.wikipedia.org/wiki/Hot-dip_galvanizing
• Ignjatovic N, Brankovic Z, Dramicanin M, Nedeljkovic J. M, and Uskokovic D. P, Preperation of TiO2 and ZnO Thin Films by Dip-Coating Method. Materials Sciences Forum. 1998; 282-283:147-152. DOI:10.4028/www.scientific.net/MSF.282-283.147.
• Jin M, Ying L. S, Preperation of ZnO films by reactive evaporation. Thin Solid Films. 1994; 237: 16-18. DOI:10.1016/0040-6090(94)90230-5.
• Aktaruzzaman A. F, Sharma G. L, Malhotra L.K, Electrical and Optical Properties of Germanium-Doped Zinc Oxide Thin Films. Thin Solid Films. 1991; 198: 67-74. DOI:10.1016/0040-6090(91)90325-R.
• Chen Z, Shum K, Salagai T, Zhang W, Strobl K, ZnO thin films synthesized by chemical vapor deposition. Applications and Technology Conference (LISAT), 7 May 2010; 1-6. DOI: 10.1109/LISAT.2010.5478331.
• Erarslan N, Güngör T, The determination of the thickness and optical constants of the ZnO crystalline thin film by using pointwise unconstrained minimization algorithm. Journal of Graduate School of Natural and Applied Sciences of Mehmet Akif Ersoy University. 2010; 2: 181-193.
• Gungor E, Gungor T, Effect of the substrate movement on the optical properties of ZnO thin films deposited by ultrasonic spray pyrolysis, Advances in Materials Science and Engineering. 2012;1-7 Article ID 594971. DOI: 10.1155/2012/594971.
• E. Gungor, T. Gungor, D. Caliskan, A, Ceylan, and E. Ozbay, Applied Surface Science, 318, 309–313 (2014). DOI:10.1016/j.apsusc.2014.06.132.
• Lee J. H, Park B. O, Transparent conducting ZnO:Al, In and Sn thin films deposited by the sol–gel method. Thin Solid Films. 2002; 426: 94-99. DOI: 10.1016/0040-6090(91)90325-R.
• Gungor T, Gungor E, Computer Controlled Dip Coating System Design. Journal of Graduate School of Natural and Applied Sciences of Mehmet Akif Ersoy University. 2012; 3:1-4.
• Birgin E. G, Chambouleyron I, and Martinez J. M, Estimation of optical constants of thin films using unconstrained optimization. Journal of Computational Physics. 1999; 151: 862-888.