Electrode dependence of resistive switching in Mn-doped ZnO: Filamentary versus interfacial mechanisms

We carry out a comparative study on resistive switching in Mn-doped ZnO thin films; samples grown on Pt and Si show unipolar and bipolar switching behaviors, respectively. Fittings of the current-voltage curves and area dependence of the device resistance reveal the filamentary conduction in Pt/Mn:ZnO/Pt. On the other hand, the interfacial effect dominates in Pt/Mn:ZnO/Si, and its low resistance state exponentially relaxes toward the high resistance state in contrast to the good data retention in Pt/Mn:ZnO/Pt. Our results suggest that selecting electrodes dictates the resistive switching mechanism presumably by affecting the migration dynamics of oxygen vacancies. (C) 2010 American Institute of Physics. [doi:10.1063/1.3428365]