Figure 1
From: Gate-tunable graphene-based Hall sensors on flexible substrates with increased sensitivity
Device schematic and the I-V characteristics of the top gated graphene based flexible Hall sensor. (a) Comparison of measured ∆VH and basic operating principles using a DC gate voltage and an AC modulated gate voltage across the charge neutrality point. In the latter, both sensitivity maxima for n- and p-type conductance can be utilized and the effective sensitivity is doubled by AC gate modulation. (b) Isometric device schematic of the top gated graphene Hall sensor with corresponding biasing scheme (top). Schematic illustration of the cross section along the red dashed line in the device schematic (bottom). Graphene and Al2O3 encapsulation are indicated in grey and green colors respectively. (c) Optical microscope image of a device after fabrication with four probing metal pads and top gate. A constant bias voltage VC is applied between the contacts S and D and ∆VH is measured between the contact V1 and V2. Gate voltage VG is applied to the contact G. d) Room temperature two terminal top gate characteristic of the fabricated device at VC of 300 mV.
