Structure and Resistive Switching Behaviors of Cu Doped ZnO Nanorod Array Films

Cu doped ZnO (CZO) nanorod films (NRF) were fabricated on CZO thin films (TF) coated FTO substrates by the hydrothermal method, and the microstructure and resistive switching characteristics were further investigated. The doping of Cu2+ helps to improve the quality of crystallization and the oriented growth of nanorods along c axis, in the meantime, effectively compensates the intrinsic defects of nanorods. The prepared CZO NRF/CZO TF devices exhibit bipolar resistive switching behaviors. The compliance current has a great effect on I-V curves and retention performance, and the OFF/ON ratio decreases under a low value of I-CC. The mean OFF/ON ratios are 7460 and 45 when I-CC =10 mA and 1 mA, respectively. Compared with the CZO TF devices, CZO NRF/CZO TF devices show narrow distribution of V-SET and good stability of HRS and LRS, with the V(SET )of +0.3 similar to 1.55 V, HRS of 7.05 x10(5)similar to 2.1 x 10(6) Omega and LRS of approximate to 134 Omega. CZO nanorods provide large quantities of oxygen vacancy for the formation of conductive filaments with orderly arrangement and uniform size.