Investigation of sheet resistance variation with annealing temperature and development of highly sensitive and selective room temperature ammonia gas sensor using functionalized graphene oxide

In the present study, a highly sensitive room temperature ammonia gas sensor with good selective property has been fabricated using functionalized graphene oxide (GO). Sheet resistance variation of the GO and functionalized GO have been observed at different annealing temperature and it has been observed that the sheet resistance decreases with the increases of the annealing temperature. The response of the sensor was calculated by recording the change in the resistance of the functionalized GO in the presence of ammonia gas. Various other sensing parameters such as sensor response & recovery time, repeatability, and long-term stability of the sensor have also been investigated. The response of the sensor was observed for ammonia concentration 100-3000 ppm at room temperature with relative humidity (RH) of 40%. The maximum sensor response observed is in the range of 32.7% to 64.9% for ammonia concentration 100-3000 ppm with response and recovery time, 10 s and 90 s, respectively.