Determination and Analysis of Structural and Optical Properties for Thermally Evaporated ZnO Thin Films


ZnO films have been deposited on glass slide substrates at room temperature by thermal evaporation technique. The prepared samples were annealed at temperature of 300°C and 400°C in air atmosphere. Optical and structural properties of as-deposited films have been compared by that of the annealed samples. X-ray diffraction (XRD) patterns of the obtained films showed that they have polycrystalline and exhibit wurtzite structure. Micro-structural properties such as mean crystallite size and micro-strain were discussed from XRD peak broadening. Optical properties were identified by measuring transmittance using UV-Vis spectrophotometer. The optical constants such as the refractive index n, extinction coefficient k as well as films’ thickness were calculated in the spectral range of 350-800 nm from transmittance data using a reverse engineering method (point-wise unconstrained minimization approach, PUMA). Dispersion of refractive index shows similar trend as Cauchy relation. Absorption coefficient depicts a maximal value around 3.33 eV for annealed samples. Using balance between electrical power and emissive power, the temperature of tungsten furnace was calculated under deposition condition. The connection between temperature and vapor pressure of ZnO was estimated by the Clausius-Clapyeron equation and thermochemical data.

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F. Rahimi, A. Rahmati and S. Mardani, "Determination and Analysis of Structural and Optical Properties for Thermally Evaporated ZnO Thin Films," Soft Nanoscience Letters, Vol. 4 No. 1, 2014, pp. 1-5. doi: 10.4236/snl.2014.41001.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] C. Li, G. J. Fang, Y. Y. Ren, Q. Fu and X. Z. Zhao, “Silver Nanoisland Induced Synthesis of ZnO Nanostructures by Vapor Phase Transport,” Journal of Nanoscience and Nanotechnology, Vol. 6, No. 5, 2006, 1467-1473.
[2] Janotti and C. G. Van de Walle, “Fundamentals of zinc oxide as a semiconductor,” Reports on Progress in Physics, Vol. 72, 2009, Article ID: 126501.
[3] Sharma, B. P. Singh, S. Dhar, A. Gondorf and M. Spasova, “Effect of Surface Groups on the Luminescence Property of ZnO Nanoparticles Synthesized by Sol-Gel Route,” Surface Science, Vol. 606, No. 3-4, 2012, L13-L17.
[4] Y. S. Chang and J. M. Ting, “Growth of ZnO Thin Films and Whiskers,” Thin Solid Films, Vol. 398-399, 2001, pp. 29-34.
[5] E. G. Birgin, I. Chambouleyron and J. M. Martinez, “Estimation of the Optical Constants and the Thickness of Thin Films Using Unconstrained Optimization,” Journal of Computational Physics, Vol. 151, No. 2, 1999, pp. 862-880.
[6] S. Heavens, “Optical Properties of Thin Films,” Dover, New York, 1991.
[7] R. Swanepoel, “Determination of the Thickness and Optical Constants of Amorphous Silicon,” Journal of Physics E: Scientific Instruments, Vol. 16, 1983, pp. 1214-1222.
[8] D. Poelman and P. F. Smet, “Methods for the Determination of the Optical Constants of Thin Films from Single Transmission Measurements: A Critical Review,” Journal of Physics D: Applied Physics, Vol. 36, 2003, pp. 1850-1857.
[9] J. Singh, “Optical Properties of Condensed Matter and Applications,” John Willey & Sons Ltd., Hoboken, 2006.
[10] H. P. Klug and L. E. Alexander, “X-Ray Diffraction Procedure for Polycrystalline and Amorphous Materials,” Wiley, New York, 1974.
[11] E. Warren, “X-Ray Diffraction,” Addison Wesley Publishing Co., London, 1969.
[12] M. Ohring, “Materials Science of Thin Films, Deposition & Structure,” 2nd Edition, Academic Press, Waltham, 2002.
[13] Emissivity Coefficient.
[14] M. Binnewies and E. Milke, “Thermochemical Data of Elements and Compounds,” 2nd Edition, Wiley-VCH, Hannover, 2002.

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