# Tunneling Field-Effect Junctions with WS$_2$ barrier

## TL;DR

This study uses first-principles calculations to explore the electronic properties of Graphene/WS2/Graphene tunneling junctions, showing how interface effects influence dielectric behavior and device performance, with implications for future nanoelectronics.

## Contribution

It provides the first-principles analysis of the electronic and dielectric properties of Graphene/WS2/Graphene structures, highlighting interface effects and tunable barrier heights for device applications.

## Key findings

- Strong interface effects influence dielectric properties.
- WS2 dielectric constant is reduced from bulk values.
- Barrier height can be tuned by WS2 thickness and gate voltage.

## Abstract

Transition metal dichalcogenides (TMDCs), with their two-dimensional structures and sizable bandgaps, are good candidates for barrier materials in tunneling field-effect transistor (TFET) formed from atomic precision vertical stacks of graphene and insulating crystals of a few atomic layers in thickness. We report first-principles study of the electronic properties of the Graphene/WS$_2$/Graphene sandwich structure revealing strong interface effects on dielectric properties and predicting a high ON/OFF ratio with an appropriate WS$_2$ thickness and a suitable range of the gate voltage. Both the band spin-orbit coupling splitting and the dielectric constant of the WS$_2$ layer depend on its thickness when in contact with the graphene electrodes, indicating strong influence from graphene across the interfaces. The dielectric constant is significantly reduced from the bulk WS$_2$ value. The effective barrier height varies with WS$_2$ thickness and can be tuned by a gate voltage. These results are critical for future nanoelectronic device designs.