Resistive switching behavior of La-doped ZnO films for nonvolatile memory applications

Rare earth element La-doped ZnO polycrystalline films are prepared on Pt/Ti/SiO2/Si substrate and p-Si substrate by chemical solution deposition (CSD) method. High ROFF/RON ratios, low operation voltages within 150 switching cycles of test and long retention measurement are obtained, which indicate that the two different structure devices exhibit reversible, controllable and remarkable reliability unipolar resistive switching (RS) behaviors. The RS mechanism is related to the different substrate of the samples. The filament theory and the interface effect are suggested to be responsible for the RS phenomenon for the Pt/Ti/SiO2/Si substrate and p-Si substrate, respectively.

► La-doped ZnO films exhibit reversible, controllable and remarkable reliability unipolar resistive switching behaviors.
► Impurities La3+ doped will increase the interface trap density, which will help to increase the ON/OFF ratio.
► The filament theory is applied to explain the resistive switching (RS) phenomenon for the Pt/Ti/SiO2/Si substrate.
► The interface effect is suggested to be responsible for the RS phenomenon for Pt/ZnLaO/p-Si device.