Compact Modeling of pH-Sensitive FETs Based on Two-Dimensional Semiconductors

Abstract

We present a physics-based circuit-compatible model for pH-sensitive field-effect transistors based on two-dimensional (2D) materials. The electrostatics along the electrolyte-gated 2D-semiconductor stack is treated by solving the Poisson equation including the Site-Binding model and the Gouy-Chapman-Stern approach, while the carrier transport is described by the drift-diffusion theory. The proposed model is provided in an analytical form and then implemented in Verilog-A, making it compatible with standard technology computer-aided design tools employed for circuit simulation. The model is benchmarked against two experimental transition-metal-dichalcogenide (MoS2 and ReS2) based ion sensors, showing excellent agreement when predicting the drain current, threshold voltage shift, and current/voltage sensitivity measurements for different pH concentrations.

4 pages, 3 figures, 1 table

References in corpus (3)

• Computational 2D Materials Database: Electronic Structure of Transition-Metal Dichalcogenides and Oxides
• Carrier statistics and quantum capacitance effects on mobility extraction in two-dimensional crystal semiconductor field-effect transistors
• Large-signal model of 2DFETs: compact modeling of terminal charges and intrinsic capacitances