Resistive switching characteristics of devices having a trilayer CuAlO x structure in the dark and under visible light illumination

Abstract

The multilevel resistive switching (RS) characteristics of In/CuAlO1.85/CuAlO1.92/CuAlO1.85/heavily doped n-type Si (n+-Si) devices are studied. The sensitivity of the RS characteristics to visible light illumination provides an opportunity to realize stable and reliable RS properties. The In/CuAlO1.85/CuAlO1.92/CuAlO1.85/n+-Si device in the dark shows RS behavior, whereas the In/CuAlO1.85/CuAlO1.92/CuAlO1.85/n+-Si device under visible light illumination exhibits the set/reset-free characteristics and the absence of the hysteresis window. The oxygen vacancy (VO)–solar irradiation interaction is proposed to describe the multilevel RS characteristic for the In/CuAlO1.85/CuAlO1.92/CuAlO1.85/n+-Si device. The significant RS degradation for devices under light illumination is due to the charge change of VO states. The switching conduction mechanism is primarily described as space charge limited conduction according to the electrical transport properties measurement. The findings show the importance of simultaneous control of the positively charged VO density and VO distribution in achieving optimization of oxide-based memory devices.