Metal/Nb:SrTiO3 Schottky devices exhibit interface-controlled resistive switching (RS) characteristics with high on/off ratios, good memory retention, and high endurance cycles. This work reveals that the RS and Schottky barrier modulation are dominantly controlled by protons (from ambient moisture) assisted charge trapping/detrapping processes at the metal/Nb:SrTiO3 interface. 

Conductive oxide interfaces are gaining considerable traction for oxide electronics. In this work, such interfaces are formed using the highly scalable atomic layer deposition technique. These are then crafted into resistive switching devices, where the interface functions both as the back electrode and the source of defects for switching. This demonstration paves the way toward new types of self-rectifying devices. 

By changing defects and power dissipation, different switching mechanisms and current-voltage characteristics can be modified. The principles discovered in this work can be applied to resistive switching devices in general. 

Invited for a Special Issue: Ferroelectric and Multiferroic Materials 

By considering polarization modulated Schottky barrier height and polarization coupled interfacial deep states trapping/de-trapping, a phenomenological theory is developed to explain the current-voltage hysteresis behavior at the metal/ferroelectric interface. This work demonstrates new strategies to enhance the resistive switching performance of ferroelectric memristors via defect and interface engineering. 

We show that the combination of oxygen ionic vacancies and low-level electronic conduction is important for controlling Schottky barrier interfacial switching.