Fabrication of Highly Sensitive Graphene Electric Field Sensor by Fowler–Nordheim Injection in SiO 2

Electric field sensing can be used for the early prediction of lightning. In this study, we have suggested the method of sensitivity enhancement of graphene electric field sensor by Fowler–Nordheim (FN) injection into SiO2under the graphene. The electric field sensing mechanism relies on the transfer of electrons between graphene and the interface trap states at the SiO2/graphene interface. The charge transfer alters carrier concentration in the graphene channel, which is reflected as a change in the drain current. The FN injection increases the interface trap states. Although time constant of charge transfer between graphene and the interface trap states was slightly degraded, lower limit of detection and sensor response were improved by the FN injection; the sensor response at 1 kV/m after 30 s of FN injection was 1230% of that before FN injection. The experimental result indicates the proposed method by FN injection is widely applicable for sensitivity improvement of electric field sensor composed of two-dimensional materials.