Abstract
The transparent ZnO thin films were prepared on Si(100) substrates by the sol-gel method. The structural and optical properties of ZnO thin films, submitted to an annealing treatment in the 400–700°C ranges are studied by X-ray diffraction (XRD) and UV-visible spectroscopic ellipsometry (SE). XRD measurements show that all the films are crystallized in the hexagonal wurtzite phase and present a random orientation. Three prominent peaks, corresponding to the (100) phase (2θ ≈ 31.8°), (002) phase (2θ ≈ 34.5°), and (110) phase (2θ ≈ 36.3°) appear on the diffractograms. The crystallite size increases with increasing annealing temperature. These modifications influence the optical properties. The optical constants and thickness of the films have been determined by analysing the SE spectra. The optical bandgap has been determined from the extinction coefficient. We found that the refractive index and the extinction coefficient increase with increasing annealing temperature. The optical bandgap energy decreases with increasing annealing temperature. These mean that the optical quality of ZnO films is improved by annealing.
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Azzam R M A and Bashara N M 1977 Ellipsometry and polarized light (Amsterdam: North-Holland) p. 89
Bao D and Yao X 2001 Appl. Phys. Lett. 79 3767
Bruggeman D A G 1933 Ann. Phys. Leipzig 24 636
Chaparro A M, Martinez M A, Guillen C, Bayon R, Gutierrez M T and Herrero J 2000 Thin Solid Films 361 177
Chen S Q, Zhang J and Feng X 2005 Appl. Surf. Sci. 241 384
Fay S, Kroll U and Bucher C 2005 Sol. Energy Mater. Sol. Cells 86 385
Forouhi A R and Bloomer I 1986 Phys. Rev. B34 7018
Gupta V and Mansingh A 1996 J. Appl. Phys. 80 1063
Hoffman R L, Norris B J and Wager J F 2003 Appl. Phys. Lett. 82 733
Hong R, Huang J, He H, Fan Z and Shao J 2005 Appl. Surf. Sci. 242 346
Jellison Jr. G E 1992 Opt. Mater. 1 41
Kang H S, Kang J S, Kim J W and Lee S Y 2004 J. Appl. Phys. 95 1246
Kirkpatrick S, Gelatt C D and Vecchi M P 1983 Science 220 671
Kuo S Y, Chen W C and Cheng C P 2006 Superlattices and Microstr. 39 162
Lee J C, Kang K H and Kim S K 2000 Sol. Energy Mater. Sol. Cells 64 185
Lee J H, Ko K H and Park B O 2003 J. Cryst. Growth 247 119
Logothetidis S, Laskarakis A, Kassavetis S, Lousinian S, Gravalidis C and Kiriakidis G 2008 Thin Solid Films 516 1345
Moustaghfir A, Tomasella E, Ben Amor S, Jacquet M, Cellier J and Sauvage T 2003 Surf. Coat. Technol. 174/175 193
Natsume Y and Sakata H 2000 Thin Solid Films 372 30
Osinsky A, Dong J W, Kauser M Z, Hertog B, Dabiran A M and Chow P P 2004 Appl. Phys. Lett. 85 4272
Raham M M, Yu G L, Krishna K M, Soga T, Wantanable J J, Jimbo T and Umeno M 1998 Appl. Opt. 37 691
Romero R, Lopez M C and Leinen D 2004 Mater. Sci. Eng. B110 87
Tauc J C 1974 Amorphous and liquid semiconductor (New York: Plenum Press) p. 159
Xuea S W, Zu X T, Zhouc W L, Denga H X, Xiang X, Zhang L and Dengd H 2008 J. Alloys Compds. 448 21
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Yang, S., Liu, Y., Zhang, Y. et al. Investigation of annealing-treatment on structural and optical properties of sol-gel-derived zinc oxide thin films. Bull Mater Sci 33, 209–214 (2010). https://doi.org/10.1007/s12034-010-0032-x
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DOI: https://doi.org/10.1007/s12034-010-0032-x