Microstructural, optical and electrochromical properties of W-doped Nb2O5 thin films prepared by dip-coating process using sols obtained by the chloroalkoxide route

  • Anil Kumar
  • P. P. SahayEmail author


Undoped and W-doped Nb2O5 thin films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) in order to study the influence of W doping on their structural and morphological properties. The synthesized Nb2O5 thin films have been found to possess an orthorhombic crystal structure having crystallite sizes 10–31 nm. The UV–visible spectroscopy shows the optical bandgap ~ 3.60 eV. The cyclic voltammetric studies show that the colouration efficiency of the films improves upon W doping with the optimum value of 68.7 cm2/C at 600 nm for the 3 at.% W-doped film. The chronoamperometric studies reveal that the switching response of the films becomes better upon W doping. The electrochemical impedance spectroscopy (EIS) data has been analyzed by fitting it to the equivalent electrical circuit (EEC) using Nova software.



The use of XRD and UV–Vis measurement facilities at Centre for Interdisciplinary Research, MNNIT Allahabad, India, and FESEM and SPM characterization facilities at Central Instrument Facility, IIT BHU, Varanasi, India are gratefully acknowledged. Financial support provided under the project, Third phase of Technical Education Quality Improvement Programme (referred to as TEQIP-III), Ministry of Human Resource Development, Govt. of India is also appreciatively acknowledged.


  1. 1.
    P. Ashrit, in Transition Metal Oxide Thin FilmBased Chromogenics and Devices, Elsevier Metal Oxide Series, ed. by G. Korotcenkov (Elsevier, Cambridge, United States, 2017)  Google Scholar
  2. 2.
    M.A. Aegerter, Sol–gel chromogenic materials and devices, in Structure and Bonding: Optical and Electronic Phenomena in Sol-Gel Glasses and Modern Applications, vol. 85, ed. by R. Reisfeld, C. Jorgensen (Springer, Berlin, 1996), pp. 149–194Google Scholar
  3. 3.
    M.A. Aegerter, M. Schmitt, Y. Guo, Sol–gel niobium pentoxide coatings: applications to photovoltaic energy conversion and electrochromism. Int. J. Photoenergy 4, 1–10 (2002)CrossRefGoogle Scholar
  4. 4.
    J. He, H. Yongming, Z. Wang, L. Wei, S. Yang, W. Guitai, Yu. Wang, S. Wang, G. Haoshuang, J. Wang, Hydrothermal growth and optical properties of Nb2O5 nanorod arrays. J. Mater. Chem. C 2, 8185 (2014)CrossRefGoogle Scholar
  5. 5.
    J.K. Dash, L. Chen, M.R. Topka, P.H. Dinolfo, L.H. Zhang, K. Kisslinger, T.-M. Lua, G.-C. Wang, A simple growth method for Nb2O5 films and their optical properties. RSC Adv. 5, 36129 (2015)CrossRefGoogle Scholar
  6. 6.
    E. Pehlivan, K. Koc, F.Z. Tepehan, G.G. Tepehan, Structural, optical and electrochromic properties of tantalum pentoxide-doped niobium pentoxide thin films. J. Sol Gel Sci. Technol. 77, 172 (2016)CrossRefGoogle Scholar
  7. 7.
    A. Verma, P.K. Singh, Sol–gel derived nanostructured niobium pentoxide thin films for electrochromic applications. Ind. J. Chem. 52A, 593 (2013)Google Scholar
  8. 8.
    A. Pawlicka, M. Atik, M.A. Aegerter, Synthesis of multicolor Nb2O5 coatings for electrochromic devices. Thin Solid Films 301, 236 (1997)CrossRefGoogle Scholar
  9. 9.
    M. Schmitt, M.A. Aegerter, Electrochromic properties of pure and doped Nb2O5 coatings and devices. Electrochim. Acta 46, 2105 (2001)CrossRefGoogle Scholar
  10. 10.
    S. Heusing, D.-L. Sun, J. Otero-Anaya, M.A. Aegerter, Grey, brown and blue coloring sol–gel electrochromic devices. Thin Solid Films 502, 240 (2006)CrossRefGoogle Scholar
  11. 11.
    E. Pehlivan, F.Z. Tepehan, G.G. Tepehan, Comparison of optical, structural and electrochromic properties of undoped and WO3-doped Nb2O5 thin films. Solid State Ionics 165, 105 (2003)CrossRefGoogle Scholar
  12. 12.
    A.M. Al-Baradi, M.M. El-Nahass, A.M. Hassanien, A.A. Atta, M.S. Alqahtani, A.O. Aldawsari, Influence of RF sputtering power on structural and optical properties of Nb2O5 thin films. Optik 168, 853 (2018)CrossRefGoogle Scholar
  13. 13.
    S.H. Mujawar, A.I. Inamdar, C.A. Betty, V. Ganesan, P.S. Patil, Effect of post annealing treatment on electrochromic properties of spray deposited niobium oxide thin films. Electrochim. Acta 52, 4899 (2007)CrossRefGoogle Scholar
  14. 14.
    T. Maruyama, T. Kanagawa, Electrochromic properties of niobium oxide thin films prepared by chemical vapor deposition. J. Electrochem. Soc. 141, 2868 (1994)CrossRefGoogle Scholar
  15. 15.
    H. Wen, Z. Liu, J. Wang, Q. Yang, Y. Li, Yu. Jerry, Facile synthesis of Nb2O5 nanorod array films and their electrochemical properties. Appl. Surf. Sci. 257, 10084 (2011)CrossRefGoogle Scholar
  16. 16.
    X. Tang, X. Yan, Dip-coating for fibrous materials: mechanism, methods and applications. J. Sol Gel Sci. Technol. 81, 378 (2017)CrossRefGoogle Scholar
  17. 17.
    C.J. Brinker, G.W. Scherer, Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing (Academic Press, Boston, 2013)Google Scholar
  18. 18.
    N. Ozer, D.-G. Chen, C.M. Lampert, Preparation and properties of spin-coated Nb2O5 films by the sol–gel process for electrochromic applications. Thin Solid Films 277, 162 (1996)CrossRefGoogle Scholar
  19. 19.
    N. Ozer, M.D. Rubin, C.M. Lampert, Optical and electrochemical characteristics of niobium oxide films prepared by sol-gel process and magnetron sputtering: a comparison. Sol. Energy Mater. Sol. Cells 40, 285 (1996)CrossRefGoogle Scholar
  20. 20.
    A.M. Raba, J. Bautista-Ruíz, M.R. Joy, Synthesis and structural properties of niobium pentoxide powders: a comparative study of the growth process. Mater. Res. 19, 1381 (2016)CrossRefGoogle Scholar
  21. 21.
    D. Beena, K.J. Lethy, R. Vinodkumar, V.P.M. Pillai, V. Ganesan, D.M. Phase, S.K. Sudheer, Effect of substrate temperature on structural, optical and electrical properties of pulsed laser ablated nanostructured indium oxide films. Appl. Surf. Sci. 255, 8334 (2009)CrossRefGoogle Scholar
  22. 22.
    A. Goswami, Thin Film Fundamentals (New Age International (P) Ltd., New Delhi, 2005)Google Scholar
  23. 23.
    N. Usha, R. Sivakumar, C. Sanjeeviraja, Structural, optical and electrochromic properties of Nb2O5:MoO3 (95:5, 90:10, and 85:15) thin films prepared by RF magnetron sputtering technique. Mater. Lett. 229, 189 (2018)CrossRefGoogle Scholar
  24. 24.
    C.G. Granqvist, Handbook of Inorganic Electrochromic Materials (Elsevier, Amsterdam, 2002)Google Scholar
  25. 25.
    J.M. O-Rueda de León, D.R. Acosta, U. Pal, L. Castañeda, Improving electrochromic behavior of spray pyrolised WO3 thin solid films by Mo doping. Electrochim. Acta 56, 2599 (2011)CrossRefGoogle Scholar
  26. 26.
    R. Mukherjee, P.P. Sahay, Improved electrochromic performance in sprayed WO3 thin films upon Sb doping. J. Alloys Compd. 660, 336 (2016)CrossRefGoogle Scholar
  27. 27.
    A. Kumar, C.S. Prajapati, P.P. Sahay, Modification in the microstructural and electrochromic properties of spray-pyrolysed WO3 thin films upon Mo doping. J. Sol Gel Sci. Technol. 90, 281 (2019)CrossRefGoogle Scholar
  28. 28.
    S.R. Bathe, P.S. Patil, Influence of Nb doping on the electrochromic properties of WO3 films. J. Phys. D Appl. Phys. 40, 7423 (2007)CrossRefGoogle Scholar
  29. 29.
    S.H. Lee, H.M. Cheong, C.E. Tracy, A. Mascarenhas, J.R. Pitts, G. Jorgensen, S.K. Deb, Alternating current impedance and Raman spectroscopic study on electrochromic a-WO3 films. Appl. Phys. Lett. 76, 3908 (2000)CrossRefGoogle Scholar
  30. 30.
    C.-J. Tang, J.-L. He, C.-C. Jaing, C.-J. Liang, C.-H. Chou, C.-Y. Han, C.-L. Tien, An all-solid-state electrochromic device based on WO3–Nb2O5 composite films prepared by fast-alternating bipolar-pulsed reactive magnetron sputtering. Coatings 9, 9 (2019)CrossRefGoogle Scholar
  31. 31.
    D.D. Yao, R.A. Rani, A.P. O’Mullane, K. Kalantar-zadeh, J.Z. Ou, High performance electrochromic devices based on anodized nanoporous Nb2O5. J. Phys. Chem. C 118, 476 (2014)CrossRefGoogle Scholar
  32. 32.
    J. He, L. You, D.T. Tran, J. Mei, Low-temperature thermally-annealed niobium oxide thin films as a minimally color changing ion storage layer in solution-processed polymer electrochromic devices. ACS Appl. Mater. Interfaces 11, 4169 (2019)CrossRefGoogle Scholar

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Authors and Affiliations

  1. 1.Department of PhysicsMotilal Nehru National Institute of Technology AllahabadPrayagrajIndia

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