Surface morphology, optical properties and Urbach tail of spray deposited Co3O4 thin films

  • Muslima Zahan
  • Jiban PodderEmail author


Cobalt oxide (Co3O4) thin films were deposited onto glass substrates by a simple spray pyrolysis technique using Co (CH3COO)2 .4H2O as a precursor material. The as-deposited films were characterized using field emission scanning electron microscope (FESEM) and UV–visible spectrophotometer. FESEM images showed uniform and well-aligned nanofiber growth of Co3O4 thin film. The average crystallite size was found to increase from 15 to 25 nm with the increase of substrate temperature. The increase in average crystallite size may be due to the agglomeration and recrystallization of cobalt oxide nanoparticles. The absorption peaks obtained at 355 nm and 540 nm were attributed to the transitions taking place between oxygen and cobalt charge transfer (O2− → Co3+ and O2− → Co2+). The energy band gap was found to decrease from 2.35 to 2.03 eV and Urbach energy (Eu) increased from 0.73 eV to 0.84 eV with the increased substrate temperatures from 250 °C to 350 °C. The optical absorption coefficient exhibited an exponential dependence of photon energy following Urbach’s rule, and Urbach tail was dependent on lattice defects. The direct band gap of the Co3O4 thin film clearly showed a red shift with increasing temperature and provided an absorption favorable for bio-sensing applications.



One of the authors, Muslima Zahan is grateful to the Ministry of Science and Technology, Government of the People’s Republic of Bangladesh for granting NST fellowship for her PhD program.


  1. 1.
    Q. Tian, X. Wang, G. Huang, X. Guo, Nanoscale Res. Lett. 12, 214 (2017)Google Scholar
  2. 2.
    A. Hans, P. Garcia, Ronaldo, Jr. de Melo, A., C.B. Antonio, de Araujo, Appl. Phys. B 111, 313 (2013)Google Scholar
  3. 3.
    C. Jia, S. Wu. Xifan, Annabella, Phys. Rev. B 83, 245204 (2011)Google Scholar
  4. 4.
    N. Ghobadi, M. Ganji, C. Luna, A. Ahmadpourian, A. Arman, Opt Quant Electron 48, 467 (2016)Google Scholar
  5. 5.
    M.A. Chougule, S.G. Pawar, P.R. Godse, R.D. Sakhare, S. Sen, V.B. Patil, J. Mater. Sci. 23, 772 (2012)Google Scholar
  6. 6.
    T. Chtouki, A. Louardi, B. Elidrissi, H. Erguig, J. Mater. Sci. Eng. A 3, 743 (2013)Google Scholar
  7. 7.
    P.S. Patil, P.R. Patil, L.D. Kadam, S.H. Pawar, Bull. Electrochem. 15, 307 (1999)Google Scholar
  8. 8.
    X. Su, L. Yu, G. Cheng, H. Zhang, M. Sun, L. Zhang, J. Zhang, Appl. Energy 134, 439 (2014)Google Scholar
  9. 9.
    X.H. Xia, J.P. Tu, J. Zhang, X.H. Huang, X.L. Wang, W.K. Zhang, H. Huang, ElectroChem. Commun. 10, 1815 (2008)Google Scholar
  10. 10.
    K.J. Cathro, Sol. Energy Mater. 9, 433 (1984)Google Scholar
  11. 11.
    S.A. Campbell, H.S. Kim, D.C. Gilmer, B. He, T. Ma, W.L. Gladfelter, IBM J. Res. Dev 43(3), 383 (1999)Google Scholar
  12. 12.
    E. Ghafari, X. Jiang, N. Lu, Adv, Compd. Hybrid Mater.,, (2017)Google Scholar
  13. 13.
    D. Barreca, C. Massignan, S. Daolio, M. Fabrizio, C. Piccirillo, L. Armelao, E. Tondello, Chem. Mater. 13(2), 588 (2001)Google Scholar
  14. 14.
    D. Dastan, P.U. Londhe, N.B. Chaure, J. Mater. Sci.,, (2014)Google Scholar
  15. 15.
    J. Wollenstein, M. Burgmair, G. Plescher, T. Sulima, J. Hildenbrand, H. Bottner, I. Eisele, Sens. Actuators B 93, 442 (2003)Google Scholar
  16. 16.
    H. Yamamoto, S. Tanaka, J. Appl. Phys. 93, 4158 (2003)Google Scholar
  17. 17.
    S. Gerasimos, P. Armatas, E. Alexandros, Katsoulidis, Dimitris, Petrakis, J. Philippos. Chem. Mater. 22, 5739 (2010)Google Scholar
  18. 18.
    P. Kubelka, F. Munk, Z. Tech. Phys. 12, 593 (1931)Google Scholar
  19. 19.
    H. Lin, C.P. Huang, W. Li, C. Ni, S.I. Shah, Y. Tseng, Appl. Catal. B 68(1), 1 (2006)Google Scholar
  20. 20.
    R. Lopez, R. Gomez, J. Sol-Gel Sci. Tech. 61, 1 (2012)Google Scholar
  21. 21.
    T. He, P. Ehrhart, P. Meuffels, J. Appl. Phys. 79(6), 3219 (1996)Google Scholar
  22. 22.
    F. Abeles, Optical Properties of Solids (North-Holland, Amsterdam, 1972)Google Scholar
  23. 23.
    F. Urbach, Phys. Rev. 92(5), 1324 (1953)Google Scholar
  24. 24.
    M. Chavez, H. Juarez, M. Pacquiao, X. Mathews, R. Gutierrez, L. Chatel, M. Zamora, O. Portillo, Rev. Mex. Fis. 62, 124 (2016)Google Scholar
  25. 25.
    S.J. Ikhmayies, R.N. Ahmad-Bitar, J. Mater. Res. Tech. 2, 221 (2013)Google Scholar
  26. 26.
    W.D. Park, Trans. Electr. Electron. Mater. 1(4), 164 (2011)Google Scholar
  27. 27.
    C. Daniel, F.S. Wood, Fitting Equations to Data (Wiley, New York, 1971), p. 264Google Scholar
  28. 28.
    A.M.E. Raj, V. Agnes, V. Bena Jothy, C. Ravidhas, J. Wollschlager, M. Suendorf, M. Neumann, M. Jayachandran, C. Sanjeeviraja, Thin Solid Films 519(1), 129 (2010)Google Scholar
  29. 29.
    J. Melsheimer, D. Ziegler, Thin Solid Films 129(1), 35 (1985)Google Scholar
  30. 30.
    H. Yamamoto, S. Tanaka, J. Appl. Phys. 93(7), 4158 (2003)Google Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Department of PhysicsBangladesh University of Engineering & TechnologyDhakaBangladesh

Personalised recommendations