A novel carbon-nanotube gas sensor based on field ionization from branched nanostructures

¹ Thin Film and Nano-Electronic Laboratory, Nano-Electronic Center of Excellence, School of Electrical and Computer Engineering, University of Tehran, Tehran, Iran
² Department of Physics, University of Tehran, Tehran, Iran

Corresponding author: mohajer@ut.ac.ir

Received: 5 June 2010
Accepted: 6 September 2010
Published online: 30 November 2010

Abstract

Branched treelike carbon nanotubes were grown by plasma enhanced chemical vapor deposition method on a silicon wafer. Patterned structures of as grown nanostructures were used for the fabrication of a gas sensor, which operates based on the field ionization of various gases. The variations in the electrical resistivity and the emission current of the fabricated device are related to the chemisorption and field ionization mechanisms, respectively. The sensor is capable of gas detection at room temperature and at low pressures with working at low voltages. Different gases such as H₂, O₂, C₂H₂ and Ar have been used to examine the gas sensitivity characteristics of the fabricated sensors.