Effect of Temperature and Humidity on NO2 and NH3 Gas Sensitivity of Bottom-Gate Graphene FETs Prepared by ICP-CVD

Graphene was used for a sensing part of bottom-gate field-effect transistor (FET)-type gas sensors, and the sensing performance of the sensors was studied. We investigated the effect of temperature (T) and relative humidity on the gas sensitivity of bottom-gate graphene FETs prepared by the inductively coupled plasma chemical vapor deposition method. The conductivity change of graphene exposed to nitrogen oxide (NO2) and ammonia (NH3) was increased with increasing temperature and humidity. For NO2 gas, the graphene FET shows increasing I-D with increasing T and also increasing I-D with increasing humidity. However, the FET shows an opposite trend with the T and humidity for NH3 gas.