The Resistive Switching Behavior of ZnO Films Depending on Li Dopant Concentration and Electrode Materials

摘要

Lithium (0, 1.0 and 10 at.%)-doped ZnO (LiZnO) polycrystalline thin films were deposited on Pt/SiO2, LaB6/Al2O3, Au/SiO2 and 20 at.% fluorine-doped SnO2(FTO)/glass substrates by an e-beam evaporation method. Metal/LiZnO/Metal sandwich structures were constructed by depositing different top electrodes (Ag, Al and Au) to find memristive characteristics depending on the lithium content and electrode materials. Compared with undoped and 1%Li-doped ZnO devices, the 10 at.%Li-doped ZnO (10LiZnO) device exhibits resistive switching memory. The Ag/10LiZnO/Pt and Ag/10LiZnO/LaB6 memory devices exhibit unipolar resistive switching behavior while bipolar resistive switching in Ag/10LiZnO/FTO, Au/10LiZnO/FTO and Al/10LiZnO/LaB6 structures is revealed. The dominant conduction mechanisms are explained in terms of Ohmic behavior, space charge limited current (SCLC) and Schottky emission for the URS and BRS behaviors.