Diodelike and resistive hysteresis behavior of heterolayered BiFeO_3/ZnO ferroelectric thin films

摘要

BiFeO_3/ZnO, ZnO/BiFeO_3, BiFeO_3/ZnO/BiFeO_3, and ZnO/BiFeO_3/ZnO thin film heterostructures were deposited on SrRuO_3/Pt(lll)/TiO_2/SiO_2/Si(100) substrates by off-axis radio frequency sputtering. Their diodelike and resistive hysteresis behavior are dependent on the combination sequence of the constituent layers in the heterostructures. Both the diodelike and resistive hysteresis behavior were clearly observed in BiFeO_3/ZnO and ZnO/BiFeO_3. The phenomena became more apparent with rising temperature. The behavior arises from the interface formed between BiFeO_3 and ZnO. As expected, the diodelike and resistive hysteresis behavior are weakened and almost disappeared in the case of BiFeO_3/ZnO/BiFeO_3 and ZnO/BiFeO_3/ZnO, where the two interfaces are equal and opposite to each other. The interface-limited Fowler-Nordheim tunneling in the high electric field region is demonstrated to involve in the formation of resistive hysteresis.