Conduction in In2O3/YSZ heterostructures: Complex interplay between electrons and ions, mediated by interfaces

Abstract

Thin film In2O3/YSZ heterostructures exhibit significant increases in electrical conductance with time when small in-plane electric fields are applied. Contact resistances between the current electrodes and film and between the current electrodes and substrate are responsible for the behavior. With an in-plane electric field, different field profiles are established in the two materials, with the result that oxygen ions can be driven across the heterointerface, altering the doping of the n-type In2O3. A low frequency inductive feature observed in AC impedance spectroscopy measurements under DC bias conditions was found to be due to frequency-dependent changes in the contact resistance.