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. ForNO₂gas, the graphene FET shows increasingIDwith increasingTand also increasingIDwith increasing humidity. However, the FET shows an opposite trend with theTand humidity forNH₃gas.