Feasibility of ultra-sensitive 2D layered Hall elements

Abstract

A Hall effect sensor is an analog transducer that detects a magnetic flux. The general requirements for its high magnetic sensitivity in conventional semiconductors are high carrier mobility and ultra-thin conduction channel in the material’s and the device’s point of view. Recently, graphene Hall elements (GHEs) that satisfy those conditions have been demonstrated with a current-normalized magnetic sensitivity (SI) superior to that of Si-based Hall sensors. Nevertheless, the feasibility of Hall elements based on an atomically thin monolayer transition metal dichalcogenide (TMD) system has not been studied thus far, although such a system would further enable a largely suppressed 2D carrier density. Herein, we show the strategy how to achieve the highest possible SI in a TMD-based Hall element in terms of the device structure as well as the operating bias condition. A monolayer molybdenum disulfide Hall element (MHE) on a hexagonal boron nitride (h-BN) thin film was fabricated, and the best bias conditions were selected based on the analytical model for zero-field transconductance data. Finally, the maximum SI of MHE/h-BN was found to be ~3000 V/AT. This work sheds light on the feasibility of TMD-based Hall element systems.