# Semi-analytical model of the contact resistance in two-dimensional semiconductors

## TL;DR

This paper presents a semi-analytical model for contact resistance in 2D semiconductors that accounts for 2D transport and Schottky barrier modulation, explaining experimental metallic behavior in contact resistance.

## Contribution

The work introduces a semi-analytical model based on Bardeen's approach that captures key effects neglected in previous models, improving understanding of contact resistance in 2D semiconductors.

## Key findings

- Model reproduces metallic behavior in contact resistance at high gate voltage.
- Accounts for temperature dependence and Schottky barrier modulation.
- Explains experimental observations of contact resistance in 2D devices.

## Abstract

Contact resistance is a severe performance bottleneck for electronic devices based on two-dimensional layered (2D) semiconductors, whose contacts are Schottky rather than Ohmic. Although there is general consensus that the injection mechanism changes from thermionic to tunneling with gate biasing, existing models tend to oversimplify the transport problem, by neglecting the 2D transport nature and the modulation of the Schottky barrier height, the latter being of particular importance in back-gated devices. In this work, we develop a semi-analytical model based on Bardeen's transfer Hamiltonian approach to describe both effects. Remarkably, our model is able to reproduce several experimental observations of a metallic behavior in the contact resistance, i.e., a decreasing resistance with decreasing temperature, occurring at high gate voltage.