Oxide 2D electron gases as a reservoir of defects for resistive switching

A non-volatile resistive switching device is demonstrated, utilizing a 2D electron gas (2DEG) between a SrTiO3 substrate and an amorphous Al2O3 layer. A large resistance window is observed, and its origin is discussed. We pinpoint the role of the oxide interface in enabling the resistive switching behavior. The switching mechanism is proposed to be of filamentary type that is formed inside the Al2O3 layer, the result of oxygen vacancies that are driven from the interface into the insulating Al2O3 under high electric fields. These results highlight the concept of memristive devices where the 2DEG serves both as the back electrode and as the source of defects necessary for resistive switching, providing a simple and scalable process for future devices.