Tunneling of photon-generated carrier in the interface barrier induced resistive switching memory behaviour.

The resistive switching effect is a great physical phenomenon that the resistance of a material can be reversibly changed by applying an electric pulse, which is useful to constructing the nonvolatile resistance random access memory (RRAM) in the next generation of memory system. In this work, a sandwich structure (ITO/WO/AZO) was prepared by using WO film (∼300 nm) as the dielectric layer meanwhile indium tin oxide (ITO) as the top electrode and aluminium-doped zinc oxide (AZO) as the bottom electrode. An enhanced resistive switching memory behavior was observed in the sample processed by light-illumination. Furthermore, the set voltage (V) and reset voltage (V) are increased but the HRS/LRS resistance ratio is decreased with the increasing of illumination time for 600 °C annealed sample. Through further analysis, a physical model on the tunneling of photon-generated carrier in the Schottky barrier layer driven by electric pulse is proposed to explain the enhanced resistive switching memory behavior. The suggested mechanism is highly pivotal for the resistive switching phenomenon to be properly applied in the nonvolatile RRAM device.