2D Dielectric Enhancement of Ion Coulomb Drag Amplification in Nanofluidics

We investigate ion-electron Coulomb drag in 2D nanofluidic slits using a generic physical model based on the Boltzmann transport formalism. The emphasis is placed on the fluid, oxide, and semiconductor dielectric constants as well as on the geometry and oxide thickness to maximize the electronic drag current and power output. Our model confirms electronic drag current amplification predicted in silicon nanochannels and shows that optimum amplification is achieved for an oxide dielectric constant equal to the geometric mean of the fluid and semiconductor constants, as well as with thin oxide layers while maintaining high surface carrier concentrations in semiconducting layers surrounding the 2D nanoslit. Our analysis, which provides guidelines for 2D slit design optimization, also shows that nanoslits made of 2D materials like graphene combined with thin oxide and optimized dielectric constants enhance drag current amplification over conventional Si/SiO2 nanochannels.