NITSRI-2D: A Surface Potential Based SPICE Compatible Model for pH-Sensitive FETs Based on 2-D Materials

We present a novel surface-potential (SP) based compact model for pH-sensitive FETs based on 2D materials, developed at the National Institute of Technology Srinagar (NITSRI). The Poisson’s equation along with site-binding theory and Gouy-chapman-stern approach is used for handling the device electrostatics towards the electrolyte side while the electrostatics in the device is addressed by employing 2-D density of states and Fermi-Dirac statistics. The proposed model is built on our prior work wherein we exhaustively demonstrated a Verilog-A implementation of our physics-based 2D material FET model, having obtained explicit surface-potential expressions using the Lambert-W function and Halley’s correction method, while subsequently computing the drain current using the drift-diffusion transport model. Experimental data belonging to a MoS
2
-based ISFET is used for validating the proposed model and the experimental results show a very good match with model results illustrating its robustness and predictive ability.