Parametric Analysis of NO2 Gas Sensor Based on Carbon Nanotubes

Two types of carbon nanotubes [single walled nanotubes (SWCNTs) and multi walled carbon nanotubes (MWCNTs)] are deposited on porous silicon by the drop casting technique. Upon exposure to test gas mixing ratio 3% NO2, the sensitivity response results show that the SWCNTs' sensitivity reaches to 79.8%, where MWCNTs' is 59.6%. The study shows that sensitivity response of the films increases with an increase in the operating temperature up to 200 degrees C and 150 degrees C for MWCNTs and SWCNTs. The response and recovery time is about 19 s and 54 s at 200 degrees C for MWCNTs, respectively, and 20 s and 56 s at 150 degrees C for SWCNTs.