Unipolar resistive switching behavior of Pt/LixZn1-xO/Pt resistive random access memory devices controlled by various defect types

The unipolar resistive switching behavior of Pt/LixZn1-xO/Pt structures fabricated via radio-frequency magnetron sputtering is investigated. Various Li doping concentrations influence the defect types (i.e., V-O, Li-i, and Li-Zn) in LixZn1-xO films for adjustable resistance ratio. The resistance ratio reaches 10(8) due to the minimized leakage current in the high-resistance state (HRS) at 6 at. % Li dopants. The dominant conduction mechanisms are explained in terms of Ohmic behavior and Poole-Frenkel (PF) emission. The coefficient r of the PF emission in the HRS is evaluated to confirm that the total number of defects in LixZn1-xO films decreases with increasing Li content. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4766725]