Encapsulated graphene based Hall sensors on foil with increased sensitivity

TL;DR

This paper demonstrates that encapsulating graphene-based Hall sensors on foil, especially with hexagonal boron nitride, significantly enhances their magnetic field sensitivity, achieving record performance levels.

Contribution

The study introduces a novel encapsulation method using hBN for graphene Hall sensors on foil, resulting in the highest sensitivity reported to date.

Findings

hBN encapsulation yields record sensitivity levels

PMMA encapsulation improves sensitivity over no encapsulation

Graphene Hall sensors on foil outperform previous designs

Abstract

The encapsulation of graphene based Hall sensors on foil is shown to be an effective method for improving the performance in terms of higher sensitivity for magnetic field detection. Two types of encapsulation were investigated: a simple encapsulation of graphene with polymethyl methacrylate (PMMA) as a proof of concept and an encapsulation with mechanically exfoliated hexagonal boron nitride (hBN). The Hall sensor with PMMA encapsulation already shows higher sensitivity compared to the one without encapsulation. However, the Hall sensor with graphene encapsulated between two stacks of hBN shows a current and a voltage normalized sensitivity of up to 2270 V/AT and 0.68 V/VT respectively, which are the highest reported sensitivity values for Hall sensors on foil so far.