Dissimilar-electrodes-induced asymmetric characteristic and diode effect of current transport in zinc oxide tunnel junctions

Abstract

Based on the first principles simulations and quantum transport calculations, effects of dissimilar electrodes and interfaces on the current transport and relevant electrical properties in ZnO tunnel junctions as well as the mechanism of current asymmetric characteristic adjustment have been investigated. Our results show that the potential energy, built-in electric field, electron transmission probability, current, etc. in ZnO tunnel junctions can be tailored by adopting asymmetric electrode combinations. By adopting dissimilar electrodes to fabricate different potential barriers, we have performed manipulations on current transport in ZnO tunnel junctions and realized the enhancement and even the reversal of the current asymmetric characteristic. We also demonstrate that it is the different potential energy levels of the dissimilar electrodes in asymmetric tunnel junctions playing an important role in the adjustment of current asymmetry, which is innovative and different from the mechanism of current asymmetry adjustment through strain-induced piezopotential reversal. This investigation exhibits a novel and significant method for controlling or modifying the performances of electronic devices by utilizing dissimilar electrodes.