Effect of incorporating copper on resistive switching properties of ZnO films

• Published in: Journal of alloys and compounds Vol. 520; pp. 250 - 254
• Main Authors: Jia, C.H., Dong, Q.C., Zhang, W.F.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.04.2012; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Copper; Depletion; ELECTRICAL CONDUCTIVITY; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Low resistance; Low-field transport and mobility; piezoresistance; OXIDES; Physics; Resistive switching; SPECTRA; Surface double layers, schottky barriers, and work functions; Switching; THIN FILMS; Tin dioxide; Tin oxides; ZINC OXIDE; ZnO:Cu; ZnO:Cu; Resistive switching; Electrical switching; Atomic force microscopy; Electrical conductivity; Doping; Copper additions; Pulsed laser deposition; XRD; Thin films; Complex impedance; Wurtzite structure; Zinc oxide; Bipolar technology; IV characteristic
• DOI: 10.1016/j.jallcom.2012.01.035
• ISSN: 0925-8388

► The ON/OFF ratio of resistance switching effects increases by introducing Cu in ZnO. ► The change of resistance is accompanied with the variance of depletion width. ► The resistance switchings are supposed to be due to the change of depletion width. Undoped and copper-doped ZnO (ZnO:Cu) thin films of wurtzite structure with c-axis orientation were grown on F-doped SnO2 (FTO) substrates by pulsed laser deposition. Typical bipolar and reversible resistance switching effects were observed in these films, and the ratio of high and low resistance state (ON/OFF ratio) increases abruptly by introducing Cu. Based on the impedance spectra of ZnO and ZnO:Cu films, the change of resistance at high and low resistance states is found to be accompanied with the variance of depletion width. Furthermore, the depletion width of ZnO films changes little, while that of ZnO:Cu films varies greatly under different resistance states, which is consistent with the result of that ZnO:Cu films show a much larger ON/OFF ratio than ZnO films. Therefore, the resistance switchings are supposed to be due to the change of depletion width of Schottky barrier.