Current-voltage characteristics of silicon nitride membranes in solution

Recently, the dielectric breakdown of insulating membranes in solution has been utilized to fabricate nanopore sensors for various molecular detection applications. Generally, the breakdown phenomenon of an insulator is thought to be strongly related to the behavior of the current through it. However, until now, the current through an insulating membrane in solution has rarely been measured. In this study, by using thin SiN membranes with large and precisely defined areas, we achieved accurate and reproducible measurements of the current-voltage (I-V) characteristics of SiN membranes in solution. From the shape of the I-V curves and their temperature dependence, the carrier conduction process in the membrane was found to be mainly governed by the Poole-Frenkel emission and tunnel conduction of the electrons which ions in solution transfer to the membrane. In addition, we investigated how the I-V characteristics and breakdown voltage changed in accordance with the changes in the solution pH, solute type, solute concentration and solvent type.