Conduction mechanisms in SnO2 single-nanowire gas sensors: An impedance spectroscopy study

• DOI: 10.1016/j.snb.2016.10.061
• Publication Date: 2016-10-17T13:56:35Z
• Authors: F. Schipani; D.R. Miller; M.A. Ponce; C.M. Aldao; S.A. Akbar; P.A. Morris; J.C. Xu
• Keywords: Contact resistance

Abstract Results of studies on single and multiple SnO 2 nanowire gas sensors with impedance spectroscopy are reported. Equivalent circuit modeling is used to draw fundamental conclusions about the dominant conduction mechanism in single-nanowire sensors, where the diameter of the nanowire is found to play a key role. This is then extended to multiple-nanowire sensors. For single-nanowire sensors, I–V measurements are also used to demonstrate that the contribution from the electrode-nanowire contact to the overall resistance changes with atmosphere and temperature. We find that for the randomly-orientated multiple-nanowire sensors, the main contribution to the resistance comes from the nanowire–nanowire junction.