A Phase Sensitive Measurement Technique for Boosted Response Speed of Graphene Fet Gas Sensor

This work presents a new class of gas sensing scheme: the phase sensitive signal on the GFET (Graphene Field Effect Transistor) gas sensors aiming to boost the response speed. Compared with the state-of-art gas sensing reports on measurements of DC resistance changes which are limited by trap states, three distinctive advancements have been achieved on graphene FETs in responses to water vapor: (1) experimental validations of a faster saturation and recovery speed, (2) in-situ measurements of field effect mobility µ and DC carrier concentration NGFET, and (3) multiple charge transfer processes through the plot of NGFET versus µ-1. As such, the proposed sensing scheme and results could open up a new frontier for graphene FET-based gas sensor with fast sensing speed in practical usages.