Vertical Tunneling Graphene Heterostructure-Based Transistor for Pressure Sensing

In this letter, a pressure sensor based on the vertical tunneling graphene field-effect transistors (VTGFETs) is proposed and theoretically analyzed. The proposed sensor consists of a graphene-hexagonal boron nitride (hBN) heterostructure. Molecular dynamic simulations are used to evaluate the strain distribution and stress-strain relation of the sensor. The device characteristics of VTGFET under pressure are investigated, by employing an atomistic tight-binding model along with the nonequilibrium Green´s function formalism. The dependency of the tunneling current variation and the sensitivity on the number of hBN layers, bias voltages, and temperature are studied and appropriate parameters for optimal performance are calculated. A nonlinearity error of 3.2% within the range of 30 GPa and a sensitivity of ~1300 pA/A/Pa for a VTGFET with six layers of hBN are predicted.