Enhancement of Sensor Response in Graphene Gas Sensors by Gate-Induced Field

The effects of the gate-induced field on sensor response in functionalized graphene sensor have not been fully understood yet. In this letter, graphene sensors decorated with Pd nanoparticles were fabricated, and gate voltage dependences of drain current and sensor response to hydrogen were experimentally and numerically examined. The sensor response was enhanced in the gate-induced electron conduction regime, compared to that in hole conduction regime. By utilizing the non-equilibrium Green's function calculations, the origin of the response enhancement was modeled as asymmetric potentials for holes and electrons. We conclude that the sensor response of graphene can be enhanced using the gate-induced electric field in various types of graphene sensors.