Abstract
We report the fabrication of carbon nanotubes based thin film sensor for studying the gas sensing properties of carbon mono-oxide gas. RF sputtered nickel film has been used as a catalyst for growth of carbon nanotubes. The nanotubes are multi-walled with diameter varying in the range of 30-60 nm. The length of these nanotubes is of several tens of micrometers. We have deposited gold electrodes on the sensing film using thermal evaporation to study the CNTs film sensor. The gas sensing properties of CNTs film for different concentration of carbon mono-oxide (CO) have been investigated. The sample gives fast response to CO gas and the sensor recovery is also quick. We also observe a decrease in resistance of this sample with the increase in CO gas concentration. The sensitivity and responsiveness has also been determined using the convention relation. These parameters are found to decrease on increasing the CO gas concentration.