Resistive switching behavior of (Zn1−xMgx)O films prepared by sol–gel processes

Highly c-axis oriented sol–gel (Zn1 − xMgx)O films were deposited on Pt/Ti/SiO2/Si substrates. Resistive switching behaviors with stable switching and high resistance ratio were demonstrated for the Pt/(Zn0.9Mg0.1)O/Pt stacks. The effect of the film thickness and the annealing temperature on resistive switching was discussed. Higher substitution of Mg for Zn results in higher resistance of (Zn1 − xMgx)O films, which is beneficial for resistive switching to occur at thinner film thickness. The mechanisms dominating the low and the high resistance states are Ohmic conduction and Poole–Frenkel emission, respectively. The resistance ratio varies from 140 to 1000, which is much higher than the value 25 reported recently for sol–gel (Zn0.8Mg0.2)O films. Films annealed at higher annealing temperatures possess higher resistance ratio.