Effects of Annealing Treatment on Optical Properties of Anatase TiO2 Thin Films
In this investigation, anatase TiO2 thin films were
grown by radio frequency magnetron sputtering on glass substrates at
a high sputtering pressure and room temperature. The anatase films
were then annealed at 300-600 °C in air for a period of 1 hour. To
examine the structure and morphology of the films, X-ray diffraction
(XRD) and atomic force microscopy (AFM) methods were used
respectively. From X-ray diffraction patterns of the TiO2 films, it was
found that the as-deposited film showed some differences compared
with the annealed films and the intensities of the peaks of the
crystalline phase increased with the increase of annealing
temperature. From AFM images, the distinct variations in the
morphology of the thin films were also observed. The optical
constants were characterized using the transmission spectra of the
films obtained by UV-VIS-IR spectrophotometer. Besides, optical
thickness of the film deposited at room temperature was calculated
and cross-checked by taking a cross-sectional image through SEM.
The optical band gaps were evaluated through Tauc model. It was
observed that TiO2 films produced at room temperatures exhibited
high visible transmittance and transmittance decreased slightly with
the increase of annealing temperatures. The films were found to be
crystalline having anatase phase. The refractive index of the films
was found from 2.31-2.35 in the visible range. The extinction
coefficient was nearly zero in the visible range and was found to
increase with annealing temperature. The allowed indirect optical
band gap of the films was estimated to be in the range from 3.39 to
3.42 eV which showed a small variation. The allowed direct band
gap was found to increase from 3.67 to 3.72 eV. The porosity was
also found to decrease at a higher annealing temperature making the
film compact and dense.
[1] H. K. Pulker, "Coatings on Glass," Elsevier , Amsterdam, 1999.
[2] Y. M. Sung, H. J. Kim, "Sputter deposition and surface treatment of
TiO2 films for dye-sensitized solar cells using reactive RF plasma," Thin
Solid Films, vol. 515, 2007, pp. 4996-4999.
[3] W. Yang, C. A. Wolden, "Plasma-enhanced chemical vapor deposition
of TiO2 thin films for dielectric applications," Thin Solid Films, vol.
515, 2006, pp. 1708-1713.
[4] C. Euvananont, C. Junin, K. Inpor, P. Limthongkul, C. Thanachayanont,
"TiO2 optical coating layers for self-cleaning applications," Ceramics
International, vol. 34, 2008, pp. 1067-1071.
[5] C. J. Tavares, J. Vieira, L. Rebouta, G. Hungerford, P. Coutinho, V.
Teixeira, J.O. Carneiro, A.J. Fernandes, "Reactive sputtering deposition
of photocatalytic TiO2 thin films on glass substrates," Mater. Sci. Eng.,
B, vol. 138, 2007, pp. 139-143.
[6] M. Okada, M. Tazawa, P. Jin, Y. Yamada, K. Yoshimura, "Fabrication
of photocatalytic heat-mirror with TiO2/TiN/ TiO2 stacked layers,"
Vacuum, vol. 80, 2006, pp. 732-735.
[7] H. Kawasaki, T. Ohshima, Y. Yagyu, Y. Suda, S. I. Khartsev, A. M.
Grishin, "TiO2/TiN/ TiO2 heat mirrors by laser ablation of single TiN
target," J. Phys.: Confer. Series 100, 2008, 012038.
[8] S. Ray, U. Dutta, R. Das, P. Chatterjee, "Modelling of experimentally
measured optical characteristics of ITO/TiO2 transparent multi-layer heat
shields," J. Phys. D: Appl. Phys., vol. 40, 2007, pp. 2445-2451.
[9] Z. Wang, Q. Chen, X. Cai, "Metal-based transparent heat mirror for
ultraviolet curing applications," Applied Surface Science, vol. 239,
2005, pp. 262-267.
[10] P. Jin, L. Miao, S. Tanemura, G. Xu, M. Tazawa, K. Yoshimura,
"Formation and characterization of TiO2 thin films with application to a
multifunctional heat mirror," Applied Surface Science vol. 212-213,
2003, pp. 775-781.
[11] Q. Ye, P. Y. Liu, Z. F. Tang, L. Zhai, "Hydrophilic properties of nano-
TiO2 thin films deposited by RF magnetron sputtering," Vacuum,
vol. 81, 2007, pp. 627-631.
[12] M. H. Habibi, N. Talebian, J. H. Choi, "The effect of annealing on
photocatalytic properties of nanostructured titanium dioxide thin films,"
Dyes and Pigments, vol. 73, 2007, pp. 103-110.
[13] C. Yang, H. Fan, Y. Xi, J. Chen, Z. Li, "Effects of depositing
temperatures on structure and optical properties of TiO2 film deposited
by ion beam assisted electron beam evaporation" Applied Surface
Science, vol. 254, 2008, pp. 2685-2689.
[14] S. B. Amor, G. Baud, M. Jacquet, N. Pichon, « Photoprotective titania
coatings on PET substrates" Surf. Coat. Technol., vol. 102, 1998, pp.
63-72.
[15] M. S. Ghamsari, A. R. Bahramian, "High transparent sol-gel derived
nanostructured TiO2 thin film," Materials Letters, vol. 62, 2008, pp.
361-364.
[16] Z. Wang, U. Helmersson and P. O. Käll, "Optical properties of anatase
TiO2 thin films prepared by aqueous sol-gel process at low
temperature," Thin Solid Films, vol. 405, 2002, pp. 50-54.
[17] H. Sun, C. Wang, S. Pang, X. Li, Y. Tao, H. Tang, M. Liu,
"Photocatalytic TiO2 films prepared by chemical vapor deposition at
atmosphere pressure," J. Non-Cryst. Solids, vol. 354 2008, pp. 1440-
1443.
[18] Y. Q. Hou, D. M. Zhuang, G. Zhang, M. Zhao and M. S. Wu, "Influence
of annealing temperature on the properties of titanium oxide thin film,"
Applied Surface Science, vol. 218, 2003, pp. 98-106.
[19] R. Sawanepoel, "Determination of the thickness and optical constants of
amorphous silicon," J. Phys. E: Sci. Instrum., vol. 16, 1983, 1214-1222.
[20] A. Karuppasamy, A. Subrahmanyam, "Studies on the room temperature
growth of nanoanatase phase TiO2 thin films by pulsed dc magnetron
with oxygen as sputter gas," J. Appl. Phys., vol. 101, 2007, 064318.
[21] J. Tauc, "Amorphous and Liquid Semiconductors," Plenum, London,
1974.
[1] H. K. Pulker, "Coatings on Glass," Elsevier , Amsterdam, 1999.
[2] Y. M. Sung, H. J. Kim, "Sputter deposition and surface treatment of
TiO2 films for dye-sensitized solar cells using reactive RF plasma," Thin
Solid Films, vol. 515, 2007, pp. 4996-4999.
[3] W. Yang, C. A. Wolden, "Plasma-enhanced chemical vapor deposition
of TiO2 thin films for dielectric applications," Thin Solid Films, vol.
515, 2006, pp. 1708-1713.
[4] C. Euvananont, C. Junin, K. Inpor, P. Limthongkul, C. Thanachayanont,
"TiO2 optical coating layers for self-cleaning applications," Ceramics
International, vol. 34, 2008, pp. 1067-1071.
[5] C. J. Tavares, J. Vieira, L. Rebouta, G. Hungerford, P. Coutinho, V.
Teixeira, J.O. Carneiro, A.J. Fernandes, "Reactive sputtering deposition
of photocatalytic TiO2 thin films on glass substrates," Mater. Sci. Eng.,
B, vol. 138, 2007, pp. 139-143.
[6] M. Okada, M. Tazawa, P. Jin, Y. Yamada, K. Yoshimura, "Fabrication
of photocatalytic heat-mirror with TiO2/TiN/ TiO2 stacked layers,"
Vacuum, vol. 80, 2006, pp. 732-735.
[7] H. Kawasaki, T. Ohshima, Y. Yagyu, Y. Suda, S. I. Khartsev, A. M.
Grishin, "TiO2/TiN/ TiO2 heat mirrors by laser ablation of single TiN
target," J. Phys.: Confer. Series 100, 2008, 012038.
[8] S. Ray, U. Dutta, R. Das, P. Chatterjee, "Modelling of experimentally
measured optical characteristics of ITO/TiO2 transparent multi-layer heat
shields," J. Phys. D: Appl. Phys., vol. 40, 2007, pp. 2445-2451.
[9] Z. Wang, Q. Chen, X. Cai, "Metal-based transparent heat mirror for
ultraviolet curing applications," Applied Surface Science, vol. 239,
2005, pp. 262-267.
[10] P. Jin, L. Miao, S. Tanemura, G. Xu, M. Tazawa, K. Yoshimura,
"Formation and characterization of TiO2 thin films with application to a
multifunctional heat mirror," Applied Surface Science vol. 212-213,
2003, pp. 775-781.
[11] Q. Ye, P. Y. Liu, Z. F. Tang, L. Zhai, "Hydrophilic properties of nano-
TiO2 thin films deposited by RF magnetron sputtering," Vacuum,
vol. 81, 2007, pp. 627-631.
[12] M. H. Habibi, N. Talebian, J. H. Choi, "The effect of annealing on
photocatalytic properties of nanostructured titanium dioxide thin films,"
Dyes and Pigments, vol. 73, 2007, pp. 103-110.
[13] C. Yang, H. Fan, Y. Xi, J. Chen, Z. Li, "Effects of depositing
temperatures on structure and optical properties of TiO2 film deposited
by ion beam assisted electron beam evaporation" Applied Surface
Science, vol. 254, 2008, pp. 2685-2689.
[14] S. B. Amor, G. Baud, M. Jacquet, N. Pichon, « Photoprotective titania
coatings on PET substrates" Surf. Coat. Technol., vol. 102, 1998, pp.
63-72.
[15] M. S. Ghamsari, A. R. Bahramian, "High transparent sol-gel derived
nanostructured TiO2 thin film," Materials Letters, vol. 62, 2008, pp.
361-364.
[16] Z. Wang, U. Helmersson and P. O. Käll, "Optical properties of anatase
TiO2 thin films prepared by aqueous sol-gel process at low
temperature," Thin Solid Films, vol. 405, 2002, pp. 50-54.
[17] H. Sun, C. Wang, S. Pang, X. Li, Y. Tao, H. Tang, M. Liu,
"Photocatalytic TiO2 films prepared by chemical vapor deposition at
atmosphere pressure," J. Non-Cryst. Solids, vol. 354 2008, pp. 1440-
1443.
[18] Y. Q. Hou, D. M. Zhuang, G. Zhang, M. Zhao and M. S. Wu, "Influence
of annealing temperature on the properties of titanium oxide thin film,"
Applied Surface Science, vol. 218, 2003, pp. 98-106.
[19] R. Sawanepoel, "Determination of the thickness and optical constants of
amorphous silicon," J. Phys. E: Sci. Instrum., vol. 16, 1983, 1214-1222.
[20] A. Karuppasamy, A. Subrahmanyam, "Studies on the room temperature
growth of nanoanatase phase TiO2 thin films by pulsed dc magnetron
with oxygen as sputter gas," J. Appl. Phys., vol. 101, 2007, 064318.
[21] J. Tauc, "Amorphous and Liquid Semiconductors," Plenum, London,
1974.
@article{"International Journal of Mechanical, Industrial and Aerospace Sciences:52283", author = "M. M. Hasan and A. S. M. A. Haseeb and R. Saidur and H. H. Masjuki", title = "Effects of Annealing Treatment on Optical Properties of Anatase TiO2 Thin Films", abstract = "In this investigation, anatase TiO2 thin films were
grown by radio frequency magnetron sputtering on glass substrates at
a high sputtering pressure and room temperature. The anatase films
were then annealed at 300-600 °C in air for a period of 1 hour. To
examine the structure and morphology of the films, X-ray diffraction
(XRD) and atomic force microscopy (AFM) methods were used
respectively. From X-ray diffraction patterns of the TiO2 films, it was
found that the as-deposited film showed some differences compared
with the annealed films and the intensities of the peaks of the
crystalline phase increased with the increase of annealing
temperature. From AFM images, the distinct variations in the
morphology of the thin films were also observed. The optical
constants were characterized using the transmission spectra of the
films obtained by UV-VIS-IR spectrophotometer. Besides, optical
thickness of the film deposited at room temperature was calculated
and cross-checked by taking a cross-sectional image through SEM.
The optical band gaps were evaluated through Tauc model. It was
observed that TiO2 films produced at room temperatures exhibited
high visible transmittance and transmittance decreased slightly with
the increase of annealing temperatures. The films were found to be
crystalline having anatase phase. The refractive index of the films
was found from 2.31-2.35 in the visible range. The extinction
coefficient was nearly zero in the visible range and was found to
increase with annealing temperature. The allowed indirect optical
band gap of the films was estimated to be in the range from 3.39 to
3.42 eV which showed a small variation. The allowed direct band
gap was found to increase from 3.67 to 3.72 eV. The porosity was
also found to decrease at a higher annealing temperature making the
film compact and dense.", keywords = "Titanium dioxide, RF reactive sputtering, Structuralproperties, Surface morphology, Optical properties.", volume = "2", number = "4", pages = "416-5", }