FABRICATION AND CHARACTERIZATION OF CARBON NANOTUBES BASED GAS SENSORS

Abstract

We fabricate highly sensitive, responsive and cost effective, carbon nanotubes based gas sensors by using electron beam physical vapor deposition/sputtering system then lithography process followed by etching. The material used for the fabrication of gas sensor is CNT powder which was purchased from Intelligent Materials Pvt. Ltd. with the average length of SWNTs 3-8 micro meter. Due to the self association property of CNTs in suspension, we disaggregate and uniformly disperse CNTs to make the device. Gaseous molecule are absorbed by the CNT surface and charge transfer takes place between gaseous molecule and CNT. Due to this, there is a change in the conductance of the device. Finally, we obtain the V-I characteristics of two terminal metal-CNT-metal contact fabricated device. The device behavior can be explained by considering two back to back schottky diodes model. And analyzed the response time and recovery time of the sensor