The effect of oxygen vacancy on switching mechanism of ZnO resistive switching memory

Abstract

Oxygen vacancy (Vo) is believed to control the switching mechanism of metal oxide resistive switching memory. However, an accurate and quantitative theory to prove this point of view remains absent. In this letter, we propose a model combining the Poole-Frenkel effect, space charge limited current, and the modification of Vo density to simulate the current-voltage curves. The calculated results show reasonable agreements with the experimental data, which indicates that resistive switching between high resistance state and low resistance state in the devices of Al/ZnO/p+-Si is led by the density change of Vo. Furthermore, the essence of this leading effect of Vo density is explained by electrons capture and emission via oxygen vacancies. This research demonstrates the significance of Vo in theory and gives an insight into the switching mechanism.