Using double Hall sensor structure to greatly reduce voltage offset in epitaxial graphene

In this paper, we show that the very large offset voltage observed in Hall sensors exploiting the epitaxial graphene on an SiC substrate can be reduced quite effectively with the help of the double Hall sensor structure (DHSS). A record offset reduction by four orders of magnitude to the DC microvolt level is achieved. The strongly reduced offset is thermally stable, provided that the single Hall sensors of the DHSS have equal temperature coefficients of resistance and the heating/cooling procedure is performed under isothermal conditions to avoid the generation of thermoelectric voltages that add to the reduced offset.