The Effect of Tin Weight Fraction and Annealing Condition on Electrical and Optical Properties of ITO/TiO2 Nanostructured Film

Document Type : Research Paper


Department of Chemical Engineering, Hamedan University of Technology, P.O. Box 65155, Hamedan, I. R. Iran.


   High transparent conductive indium tin oxide/titanium dioxide (ITO/TiO2) nanostructured thin film is prepared by sol-gel dip-coating technique. This method yielded monodisperse ITO nanoparticles with mean diameter of 12 nm. The atomic composition of the Sn within the ITO structure changed from 0-20 wt.%. Through controlled annealing temperature at 550 oC, the results of four-point probe technique showed that the resistivity of the ITO film depends on the Sn doping ratio, the film thickness and atmospheric conditions applied during annealing. The ITO nanostructured film with thickness of 165 nm containing 8 wt.% Sn atoms annealed under vacuum condition showed a low resistivity of 5.1×10-4 Ω-cm and transparency as high as 90% with wavelengths between 500 and 700 nm. The refractive index and extinction coefficient of the ITO/TiO2 thin film is determined by using the UV-vis spectrophotometer. An optical method is used to determine the band gap of the film. Experimental results showed that the refractive index, extinction coefficient, and band gap was closely on the atmospheric conditions and crystallinity of the ITO nanostructures. The monodispersed ITO nanostructures and its preparation methodology can be used for the fabrication of novel thin films that applied for large-scale integrated opto-electronic devices.


  1. Yun, J., Park, Y. H., Bae, T. S. Lee, S., Lee, G. H. (2013). “Fabrication of a Completely Transparent and Highly Flexible ITO Nanoparticle Electrode at Room Temperature”, ACS Appl. Mater. Interfaces, 5: 164-172.
  2. Thirumoorthi, M., Joseph Prakash,J. T. (2016). “Structure, Optical and Electrical Properties of Indium Tin Oxide Ultra Thin Films prepared by Jet Nebulizer Spray Pyrolysis Technique”, J. Asian Ceram. Soc., 4: 124-132.
  3. Brewer, S. H., Franzen. S. (2004). “Calculation of the Electronic and Optical Properties of Indium Tin Oxide by Density Functional Theory”, Chem. Phys., 300: 285-293.
  4. Singh, P., Kumar, A., Kaur. D., (2008). “Growth and Characterization of New Nonlinear Optical Thioureal-alanine Acetate Single Crystal”, J. Phys. B., 403: 3769-3773.
  5. Kesim, M. T., Durucan. C. (2013). “Indium Tin Oxide Thin Films Elaborated by Sol-gel Routes: The Effect of Oxalic Acid Addition on Optoelectronic Properties”, Thin Solid Films, 545: 56-63.
  6. Chopra, K. L., Major, S., Pandya. D. K. (1983). “Thin-Film Solar Cells: An Overview”, Thin Solid Films, 108: 333-340.
  7. Schropp, R. E. I., Li, H., Rath, J. K., van der Werf. C. H. M. (2008). “Growth Mechanism of Nanocrystalline Silicon at the Phase Transition and Its Application in Thin Film Solar Cells”, Surf. Interface Anal., 40: 970-973.
  8. Xia N., Gerhardt, R .A. (2016). “Fabrication and Characterization of Highly Transparent and Conductive Indium tin Oxide Films made with Different Solution-based Methods”, Mat. Res. Express, 4: 116408-116414.
  9. Fortunato, E., Barquinha, P., Martins, R. (2012). “Oxide Semiconductor Thin-Film Transistors: A Review of Recent Advances”, Adv. Mat. 24: 2945-2986.

10. Cindemir, U., Lansåker, P., Österlund, L., Niklasson, G. A., Granqvist, C. G. (2016). “Sputter-Deposited Indium–Tin Oxide Thin Films for Acetaldehyde Gas Sensing”, Coatings, 6: 19-26.

11. Yadav, B. C., Agrahari, K., Singh, S., Yadav, T. P. (2016). “Fabrication and Characterization of Nanostructured Indium Tin Oxide film and Its Application as Humidity and Gas Sensors”, J. Materials Sci: Materials in Electronics, 27: 4172-4179.

12. Ok, K. H., Kim, J., Park, S. R., Kim, Y., Lee, C. J., Hong, S. J., Kwak, M. G., Kim, N., Han, C. J., Kim, J. W. (2015). “Ultra-thin and Smooth Transparent Electrode for Flexible and Leakage-free Organic Light-emitting Diodes”, Sci. Rep., 5: 1-8.

13. Habibi; M. H. Khaledi Sardashti, M. (2008). “Preparation and Proposed Mechanism of ZnO Nanostructure Thin Film on Glass with Highest c-axis Orientation”, Int. J. Nanosci. Nanotechnol., 4: 13-16.

  1. 14.  Kamei, M., Shigesato, Y., Takaki. S. (1995). “Origin of Characteristic Grain-subgrain Structure of Tin-doped Indium Oxide Films”, Thin Solid Films, 259: 38-45.

15. Hartmann, P., Lee, D. K., Smarsly, B., Janek. M. (2010). “Mesoporous TiO2: Comparison of Classical Sol−Gel and Nanoparticle Based Photoelectrodes for the Water Splitting Reaction”, ACS Nano, 4: 3147-3154.

16. Elmas, S., Korkmaz, S., Pat. S., (2013). “Optical Characterization of Deposited ITO Thin Films on Glass and PET Substrates”, Appl. Surf. Sci., 276: 641-645.

17. Lakshmi, J. S., John Berlin, I., Daniel, G. P., Thomas, P. V., Joy, K. (2011). “Effect of Calcination Atmosphere on Photoluminescence Properties of Nanocrystalline ZrO2 Thin Films Prepared by Sol–gel Dip Coating Method”, J. Phys. Condens. Matter, 406: 3050-3055.

18. Golobostanfard, M. R., Abdizadeh, H. (2013). “Effects of Acid Catalyst Type on structural, Morphological, and Optoelectrical Properties of Spin-coated TiO2 Thin”, J. Phys. Condens. Matter, 413: 40-46.

19. Ramanan, S. R. (2001). “Dip Coated ITO Thin-Films Through Sol–gel Process Using Metal Salts”, Thin Solid Films, 389: 207-212.

20. Fallah, H. R., Ghasemi, M., Hassanzadeh, A., Steki,H. (2006). The Effect of Deposition rate on Electrical, Optical and Structural Properties of Tin-doped Indium Oxide (ITO) Films on Glass at Low Substrate Temperature”, J. Phys. B., 373: 274-279.

21. Bahramian, A. (2013). “High Conversion Efficiency of Dye-Sensitized Solar Cells Based on Coral-like TiO2 Nanostructured Films: Synthesis and Physical Characterization”, Ind. Eng. Chem. Res. 52: 14837-14846.

22. Falahatgar, S. S., Ghodsi F. E. (2016). “Annealing Temperature Effects on the Optical Properties of MnO2: Cu Nanostructured Thin Films”, Int. J. Nonosci. Nanotechnol., 12: 7-18.

23. Lee, J., Lee, S., Li, G., Petruska, M. A., Paine, D. C., Sun, S. (2012). “A Facile Solution-Phase Approach to Transparent and Conducting ITO Nanocrystal Assemblies”, J. Am. Chem. Soc., 134: 13410-13414.

24. Gaarenstroom, S. W., Balogh, M. P Militello, M. C., Waldo, R. A., Wong, C. A., Kelly, N. A., Gibson, T. L., Kundrat, M. D.,. (2005). “Characterization of Indium-tin-oxide Films with Improved Corrosion Resistance”, Surf. Interface Anal., 37: 385-392.

25. Islam M. A., Rahman K. S., Haque F., Khan N. A., Akhtaruzzaman M., Alam M. M., Ruslan H., Sopian K., Amin, N. (2015). “Effect of Sn Doping on the Properties of Nano-Structured ZnO Thin Films Deposited by Co-Sputtering Technique”, Int.  J. Nanosci Nanotechnol., 15: 9184-9191.

26. Das, R., Ray, S. (2003). “Zinc oxide-a Transparent, Conducting IR-reflector Prepared by RF-magnetron Sputtering.” J. Phys. D: Appl. Phys., 36: 152-159.

27. Sasani Ghamsari, M., Bahramian, A. (2008). “High Transparent Sol–gel Derived Nanostructured TiO2 Thin Film”, Mat. Let., 62: 361-364.

28. Bahramian, A. (2013). “Study on Growth Rate of TiO2 Nanostructured Thin Films: Simulation by Molecular Dynamics Approach and Modeling by Artificial Neural Network”, Surf. Interface Anal., 45: 1727-1736.

29. Tao, P., Viswanath, A., Schadler, L. S., Benicewicz, B. C., Siegel, R. W., (2011). “Preparation and Optical Properties of Indium Tin Oxide/Epoxy Nanocomposites with Polyglycidyl Methacrylate Grafted Nanoparticles”, ACS Appl. Mater. Interfaces, 3: 3638-3645.

30. Hong, S. J., Han, J. I. (2006). “Indium Tin Oxide Thin Film Fabricated by Indium-Tin-Organic Sol including ITO Nanoparticle”, Curr. Appl. Phys., 6: 206-210.

31. Cullity, B. D. (1978) “Elements of X-ray Diffraction”, 2nd ed., Addison-Wesley, California.

32. Alam, M. J., Cameron. D. C. (2001). “Characterization of Transparent Conductive ITO Thin Films Deposited on Titanium Dioxide Film by a Sol-gel Process”, Surf. Coat. Technol., 142: 776-780.

33. Chan, Sh. H., Li, M. Ch., Wei, H. S., Chen, Sh. H. Kuo, Ch. Ch. (2015). “The Effect of Annealing on Nanothick Indium Tin Oxide Transparent Conductive Films for Touch Sensors”, J. Nanomaterials, 2015: 1-5.

34. Manifacier, J. C., Gasiot, J., Fillard. J. P. (1976). “A Simple Method for the Determination of the Optical Constants n, k and the Thickness of a Weakly Absorbing Thin Film”, J. Phys. E, Sci. Instrument., 9: 1002-1004.

35. Swanepoel. R. (1983). “Determination of the Thickness and Optical Constants of Amorphous Silicon”, J., Phys. E, Sci. Instrument. 16: 1214-1237.Mohamed, S.H., El-Hossary, F.M., Gamal, G.A., Kahlid, M.M. (2009). “Properties of Indium Tin Oxide Thin Films Deposited on Polymer Substrates”, Acta Physica Polonica A, 115: 704-708.

36. Sengupta, D., Das, P., Mondal, B., Mukherjee, K. (2016). “Effects of Doping, Morphology and Film-thickness of Photo-anode Materials for dye Sensitized Solar Cell Application–A review”, Renew. Sustainable Energy Rev., 60: 356-376

37. Ray, S., Dutta, U., Das, R., Chatterjee, P. (2007). “Modelling of Experimentally Measured Optical Characteristics of ITO/TiO2 Transparent Multi-layer Heat Shields”, J. Phys. D: Appl. Phys. 40: 2445-2451.

38. Fotsa-Ngaffo, F., Caricato, A. P., Romano, F. (2009) “Optical Properties of ITO/TiO2 Single and Double Layer Thin Films Deposited by RPLAD”, Appl. Surf. Sci., 255: 9684-9687.

39. Arunachalam, A., Dhanapandian, S., Manoharan, C., Sridhar, R. (2015). “Characterization of Sprayed TiO2 on ITO Substrates for Solar Cell Applications”, Spectrochimica Acta Part A, 149: 904-912.

40. Ok, J.-W., Kwak, D.-J. Kim, S.-H., Sung, Y.-M. (2014). “Conductive and Transparency Characteristics of Titanium-doped Indium-tin oxide (InSnO2:Ti) Films Deposited by Radio Frequency Magnetron Sputtering”, Vacuum, 110: 196-201.