Particle simulation of electrolytic ion motions for noise in electrolyte-insulator-semiconductor field-effect transistors

We conduct particle simulation for drain current noise in electrolyte-insulator-semiconductor field-effect transistors, to simulate how the thermal motion of charged particles near the interface affects the electrical current noise in the channel. We consider three cases: bulk electrolytes without and with charged spheres located at two different distances from the electrolyte-dielectric interface. Our results show that the drain current noise from noise sources in the electrolyte can be modeled by the sum of Lorentzian spectra, whose corner frequencies are determined by the RC product of the resistances of the bulk electrolyte and the region between the charged spheres and the interface, and the capacitance of the dielectric. Also, as the charged spheres approach the electrolyte-dielectric interface, the noise level increases, in agreement with the published experimental results.