Modeling the Electrostatics of 2-Terminal Boron or Nitrogen Substitution Doped Metal-Insulator-Graphene (MIG) Structure

In this work, the electrostatics of two-terminal (2T) Boron (B) or Nitrogen (N) substitution doped metal-insulator-graphene (MIG) is modeled by solving the Poissons equation and MIG electrical equivalent circuit model self-consistently. The effects of substitution doping such as shift in Dirac point with bandgap engineering, change in carrier sheet density, and quantum capacitance are explicitly captured in this model. The effect of quantum capacitance near the Dirac point is imperative in graphene-based devices. Consequently, the quantum capacitance of B or N substitution doped graphene near the Dirac point is modeled extensively with the effective gate capacitance as a series combination of insulating capacitance and quantum capacitance. The proposed 2T B substitution doped MIG is exhibiting improved channel sheet charge density and exhibiting the on/off channel sheet charge density of
$2.32\times 10^{3}$
for 6.25% of B-doping concentration and
$2.74\times 10^{4}$
for 25% of B-doping concentration. Subsequently, the bipolar gating effect is significantly suppressed in the case of 2T B-doped MIG when compared with 2T undoped MIG. Hence, modeling the electrostatics of substitution doped 2T MIG manifests in understanding the physical phenomenon to design the graphene-based FET with significant on/off ratio and substitution doping in graphene makes it highly suitable in digital applications.