High Resolution and High Measurement Range Electrostatic Field Sensors Based on Graphene Field Effect Transistor

Among applications in various domains, precise measurement of electrostatic fields with compact sensors is becoming a topic of primary importance in the aerospace domains for lightning strike prevention on unprotected vehicules such as drones and for the management of electronic anomalies or damages engendred by electrostatic discharges (ESD) on satellites during geomagnetic storms. Traditional heavy and large field mill sensors and their equivalent miniaturized MEMS sensors as well as electro-optics sensors are limited either by their resolution, which should be below 1 V/m for the aforementioned targeted applications, or by their measurement range which should be at least 1 MV/m. Recently a new concept of electrostatic field sensor based on Graphene Field Effect Transistor (GFET) has emerged². It has however attracted very few attention by the scientific community. Its detection mechanism is still controversial³ and its performance figures have not been thoroughly investigated yet. In this work, we show that the detection mechanism is much simpler than the previously suggested ones and relies on a convolution of the transistor effect and physics laws of electrostatics describing the potential of a floating conductor (namely, the transistor gate). Furthermore the performance figures (i.e. limit of detection, sensitivity and measurement range) are strongly dependant on the sensor geometry. With substrate sizes below a few millimetres, a trade-off between the limit of detection and the measurement range allows to span the 10^-3 Vm^-1 -10 MV.m^-1. We investigate this trade-off with a non-optimized sensors on a 15 mm large substrate.