Gate-tunable Hall sensors on large area CVD graphene protected by h-BN with 1D edge contacts

TL;DR

This paper demonstrates large-area CVD graphene Hall sensors protected by h-BN with 1D edge contacts, showing high sensitivity and tunability via gate voltage, suitable for reliable environmental operation.

Contribution

It introduces a fabrication method for protected CVD graphene Hall sensors with 1D edge contacts and demonstrates their tunable sensitivity.

Findings

Hall sensors achieve up to 345 V/(AT) sensitivity.

Gate voltage effectively tunes the Hall sensitivity.

Reliable and stable electrical properties of 1D edge contacts.

Abstract

Graphene is an excellent material for Hall sensors due to its atomically thin structure, high carrier mobility and low carrier density. However, graphene devices need to be protected from the environment for reliable and durable performance in different environmental conditions. Here we present magnetic Hall sensors fabricated on large area commercially available CVD graphene protected by exfoliated hexagonal boron nitride (h-BN). To connect the graphene active regions of Hall samples to the outputs the 1D edge contacts were utilized which show reliable and stable electrical properties. The operation of the Hall sensors shows the current-related sensitivity up to 345 V/(AT). By changing the carrier concentration and type in graphene by the application of gate voltage we are able to tune the Hall sensitivity.