Large-Scale Graphene on Hexagonal-BN Hall Elements: Prediction of Sensor Performance without Magnetic Field

Area of Science:

• Materials Science
• Nanotechnology
• Condensed Matter Physics

Background:

• Graphene Hall elements (GHEs) are promising magnetic sensors due to graphene's unique electronic properties.
• Previous fabrication methods like mechanical exfoliation and electron-beam lithography limit large-scale production feasibility.

Purpose of the Study:

• To demonstrate a high-quality graphene Hall element (GHE) array fabricated using scalable methods.
• To achieve superior magnetic sensing performance and develop a predictive analytical model for GHEs.

Main Methods:

• Fabrication of graphene on hexagonal boron nitride (h-BN) heterostructures using photolithography.
• Utilizing large-area 2-D materials grown by chemical vapor deposition (CVD).
• Development of an analytical model based on charge neutrality point shifts and transconductance data.

Main Results:

• Achieved a maximum current-normalized sensitivity of 1986 V/AT.
• Demonstrated a minimum magnetic resolution of 0.5 mG/Hz(0.5) at 300 Hz.
• Obtained an effective dynamic range exceeding 74 dB.
• Proposed a model to predict GHE operation from transconductance data without a magnetic field.

Conclusions:

• The developed GHE array exhibits high performance suitable for magnetic sensing applications.
• Scalable fabrication methods like photolithography and CVD are feasible for producing high-quality GHEs.
• The analytical model simplifies GHE design evaluation, supporting practical implementation.