Surface Morphology-Dependent Sensitivity of Thin-Film-Structured Indium Oxide-Based NO2 Gas Sensors

  • Li-Yi Jian
  • Hsin-Ying Lee
  • Ching-Ting LeeEmail author


This study investigated the sensitivity dependence of thin-film-structured NO2 gas sensors on the surface morphology of indium oxide-sensing membranes. The indium oxide-sensing membranes were deposited on quartz substrates by using a radio frequency magnetron sputtering system at various oxygen/(argon + oxygen) ratios to modify their In and O atomic percentage, surface morphology, and grain size in the membranes. According to the energy dispersive spectroscopy and x-ray diffraction results, the oxygen atomic percentage and the grain size of the indium oxide-sensing membranes increased and decreased with an increase in the oxygen/(argon + oxygen) ratio, respectively. Through atomic force microscopy, the average roughness of 50-nm-thick indium oxide films deposited at various ratios of oxygen/(argon + oxygen), namely 0% oxygen (pure argon), 20% oxygen, 60% oxygen, and 100% oxygen (pure oxygen), was found to be 0.80 nm, 0.98 nm, 2.68 nm, and 1.25 nm, respectively. The highest sensitivity of the various NO2 gas sensors was observed at an operating temperature of 150°C because of the generated \( {\hbox{O}}^{ - } \) ions and the provision of sufficient energy to overcome the required activation energy. At the operating temperature of 150°C, the sensitivity tendency of the various NO2 gas sensors was according to the surface roughness of the indium oxide-sensing membranes. Furthermore, the response and the recovery times of the various NO2 gas sensors corresponded to the surface morphology of the indium oxide-sensing membranes. The response and the recovery times of the NO2 gas sensors operated at 150°C under an NO2 gas concentration of 100 ppm were 70 s and 364 s, respectively.


Indium oxide-sensing membrane NO2 gas sensors recovery time sensitivity surface morphology 


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This work was supported by the Ministry of Science and Technology, Republic of China, under Grant MOST 105-2221-E-006-171-MY3.


  1. 1.
    A. Afzala, N. Cioffi, L. Sabbatini, and L. Torsi, Sens. Actuator B Chem. 171–172, 25 (2012).CrossRefGoogle Scholar
  2. 2.
    C.T. Lee, H.Y. Lee, and Y.S. Chiu, IEEE Sens. J. 16, 7581 (2016).Google Scholar
  3. 3.
    T. Akamatsu, T. Itoh, N. Izu, and W. Shin, Sensors 13, 12467 (2013).CrossRefGoogle Scholar
  4. 4.
    F. Yavari, E. Castillo, H. Gullapalli, P.M. Ajayan, and N. Koratkar, Appl. Phys. Lett. 100, 203120 (2012).CrossRefGoogle Scholar
  5. 5.
    T. Lv, Y.J. Chen, J.M. Ma, and L.B. Chen, RSC Adv. 4, 22487 (2014).CrossRefGoogle Scholar
  6. 6.
    D. Liu, W.W. Lei, B. Zou, S.D. Yu, J. Hao, K. Wang, B.B. Liu, Q.L. Cui, and G.T. Zou, J. Appl. Phys. 104, 083506 (2008).CrossRefGoogle Scholar
  7. 7.
    H. Steffes, C. Imawan, F. Solzbacher, and E. Obermeier, Sens. Actuator B Chem. 68, 249 (2000).CrossRefGoogle Scholar
  8. 8.
    P.C. Xu, Z.X. Cheng, Q.Y. Pan, J.Q. Xu, Q. Xiang, W.J. Yu, and Y.L. Chu, Sens. Actuator B Chem. 130, 802 (2008).CrossRefGoogle Scholar
  9. 9.
    J. Gao, L.L. Wang, K. Kan, S. Xu, L.Q. Jing, S.Q. Liu, P.K. Shen, L. Li, and K.Y. Shi, J. Mater. Chem. A 2, 949 (2014).CrossRefGoogle Scholar
  10. 10.
    L. Wang, Y.J. Chen, J.M. Ma, L.B. Chen, Z. Xu, and T.H. Wang, Sci. Rep. 3, 3500 (2013).CrossRefGoogle Scholar
  11. 11.
    S.L. Bai, L.Y. Chen, R.X. Luo, K.W. Zhang, D.Q. Li, A.F. Chen, and C.C. Liu, IEEE Sens. J. 11, 1969 (2011).CrossRefGoogle Scholar
  12. 12.
    H. Abdollahi, M. Samkan, and M.M. Hashemi, Microsyst. Technol. 24, 3741 (2018).CrossRefGoogle Scholar
  13. 13.
    F.R. Juang, W.C. Chern, and B.Y. Chen, Thin Solid Films 660, 771 (2018).CrossRefGoogle Scholar
  14. 14.
    C.M. Hung, D.T.T. Le, and N.V. Hieu, J. Sci. Adv. Mater. Devices 2, 263 (2017).CrossRefGoogle Scholar
  15. 15.
    S. Pandey, J. Sci. Adv. Mater. Devices 1, 431 (2016).CrossRefGoogle Scholar
  16. 16.
    K.R. Jawaher, R. Indirajith, S. Krishnan, R. Robert, S.K.K. Pasha, K. Deshmukh, and S.J. Das, J. Sci. Adv. Mater. Devices 3, 139 (2018).CrossRefGoogle Scholar
  17. 17.
    H. Zhang, W. Wei, K. Zhang, F. Wang, Y. Yuan, Z. Yang, T. Zhang, S. Sun, in Semiconductor Technology International Conference (2015).Google Scholar
  18. 18.
    N.S. Ramgir, Y.K. Hwang, S.H. Jhung, H.K. Kim, J.S. Hwang, I.S. Mulla, and J.S. Chang, Appl. Surf. Sci. 252, 4298 (2006).CrossRefGoogle Scholar
  19. 19.
    H.Y. Lee, H.L. Huang, and C.T. Lee, Sens. Actuator B Chem. 157, 460 (2011).CrossRefGoogle Scholar
  20. 20.
    E. Vinoth and N. Gopalakrishnan, Mater. Res. Express 5, 066413 (2018).CrossRefGoogle Scholar
  21. 21.
    T.A.H. Abbas, J. Electron. Mater. 47, 7331 (2018).CrossRefGoogle Scholar
  22. 22.
    P. Pratha, G. Gowri Devi, Y.P.V. Subbaiah, K.T. Ramakrishna Reddy, and V. Ganesan, Curr. Appl. Phys. 8, 120 (2008).CrossRefGoogle Scholar
  23. 23.
    K. Jain, R.P. Pant, and S.T. Lakshmikumar, Sens. Actuator B Chem. 113, 823 (2006).CrossRefGoogle Scholar
  24. 24.
    A.Z. Sadek, S. Choopun, W. Wlodarski, S.J. Ippolito, and K. Kalantar-zadeh, IEEE Sens. J. 7, 919 (2007).CrossRefGoogle Scholar
  25. 25.
    S.L. Bai, D.Q. Li, D.M. Han, R.X. Luo, A.F. Chen, and C.C. Liu, Sens. Actuator B Chem. 150, 749 (2010).CrossRefGoogle Scholar
  26. 26.
    X.M. Xu, D.W. Wang, J. Liu, P. Sun, Y. Guan, H. Zhang, Y.F. Sun, F.M. Liu, X.S. Liang, Y. Gao, and G.Y. Lu, Sens. Actuator B Chem. 185, 32 (2013).CrossRefGoogle Scholar
  27. 27.
    E. Oh, H.Y. Choi, S.H. Jung, S. Cho, J.C. Kim, K.H. Lee, S.W. Kang, J. Kim, J.Y. Yun, and S.H. Jeong, Sens. Actuator B Chem. 141, 239 (2009).CrossRefGoogle Scholar
  28. 28.
    R. Ferro, J.A. Rodríguez, and P. Bertrand, Thin Solid Films 516, 2225 (2008).CrossRefGoogle Scholar
  29. 29.
    M. Batzill and U. Diebold, Prog. Surf. Sci. 79, 47 (2005).CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society 2019

Authors and Affiliations

  1. 1.Department of PhotonicsNational Cheng Kung UniversityTainanTaiwan, ROC
  2. 2.Department of Electrical EngineeringYuan Ze UniversityTaoyuanTaiwan, ROC

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