Fig. 1: Schematic illustrations of the conductivity profiles versus the applied gate voltage and the corresponding physical phenomena over a graphene field-effect transistor (FET).
From: An electronic nose using a single graphene FET and machine learning for water, methanol, and ethanol
a (Top) A gas molecule can cause the lateral movement of the conductivity profile and the movement of the charge neutral point; (bottom) the physical phenomenon of the charge transfer between a gas molecule and graphene and the carrier concentration change in the band diagram. b (Top) The slope in the hole branch can be altered due to the gas molecule; (bottom) the Coulomb interactions between the gas molecule and the holes. c (Top) The slope in the electron branch can be altered due to the gas molecule; (bottom) the Coulomb interactions between the gas molecule and the electrons. d (Top) The height of the charge neutral point is changed due to the gas molecule; (bottom) the modulated residual carrier concentration in the graphene
