FeZnO-Based Resistive Switching Devices

Resistive switching characteristics in Fe-doped ZnO (FeZnO) are investigated. In the Ag/FeZnO/Pt structure, the ratio of the high-resistance state (HRS) over the low-resistance state (LRS) is 3.8 × 102. For this single oxide layer (SL)-based device, it is found that the dominant conduction mechanisms are Poole–Frenkel emission in the HRS and Ohmic behavior in the LRS, respectively. To improve the switching performance, a MgO–FeZnO bilayer (BL) is used to form an Ag/FeZnO/MgO/Pt structure, which shows a much higher HRS/LRS ratio (~106) than the SL counterpart. The FeZnO/MgO BL structure also significantly reduces dispersion of the operating parameters including current density in the HRS and the SET voltages, attributed mainly to suppression of oxygen vacancies and oxygen ions in the MgO layer of the BL structure.