Memristive behavior of ZnO film with embedded Ti nano-layers

The excellent memristive behavior of ZnO-based devices with embedded Ti nano-layers is obtained. The results show that inserting Ti layers can effectively reduce the switching voltages and increase the Roff/Ron ratio (more than 103). In particular, the stable switching properties is obtained by introducing 2.5 nm Ti layer, and the devices show good sweep endurance (about 320 cycles) and a long retention time of more than 106 s as compared with the devices without Ti layer. A model combining the redox reaction and the oxygen vacancy-based conducting filament is proposed to explain the memory effect. The conducting filament will be formed and ruptured along fixed paths at a certain region due to the non-uniform distribution of oxygen vacancies, which is responsible for the improvement of device performance.