A Model for the Current-Voltage Characteristic of Membrane/Electrolyte Junctions

A model for the current-voltage characteristic of the junction between an ion-sensitive membrane and an electrolyte solution is derived and compared with numerical simulations of the Poisson-Nernst–Planck model for ion transport. The expression resembles that of a semiconductor p-n junction with a nonideality factor of 2. The nonideality correlated to the voltage drop in the electrolyte induced by the rearrangement of the counter-ions.