Large-signal model of the Metal-Insulator-Graphene diode targeting RF applications

TL;DR

This paper introduces a comprehensive large-signal model for metal-insulator-graphene diodes, capturing their dynamic response for RF applications, including effects like image force, and validated against experimental data.

Contribution

A novel circuit-compatible large-signal model for MIG diodes that incorporates image force effects and is validated with experimental measurements.

Findings

Model accurately predicts diode behavior in RF circuits.

Inclusion of image force effect improves barrier height estimation.

Model implemented successfully in Verilog-A for circuit simulation.

Abstract

We present a circuit-design compatible large-signal compact model of metal-insulator-graphene (MIG) diodes for describing its dynamic response for the first time. The model essentially consists of a voltage-dependent diode intrinsic capacitance coupled with a static voltage-dependent current source, the latter accounts for the vertical electron transport from/towards graphene, which has been modeled by means of the Dirac-thermionic electron transport theory through the insulator barrier. Importantly, the image force effect has been found to play a key role in determining the barrier height, so it has been incorporated into the model accordingly. The resulting model has been implemented in Verilog A to be used in existing circuit simulators and benchmarked against an experimental 6-nm TiO2 barrier MIG diode working as a power detector.