Improving the Resistive Switching Performance of the Pb(Zr _0.4 Ti _0.6 )O ₃ /Nb:SrTiO ₃ Heterostructure through Fe Doping

Ferroelectric thin films have emerged as key materials for next-generation memory devices, where resistive switching (RS) performance is an important consideration for device optimization. Previous efforts to enhance RS performance have predominantly concentrated on interface engineering, whereas the synergistic effects of bulk conduction mechanisms are equally indispensable. Here, we introduce Fe doping into Pb(Zr0.4Ti0.6)O3/Nb:SrTiO3 (PZT/NSTO) heterostructures to integrate interfacial and bulk conduction mechanisms, achieving a significant performance enhancement. The 1 mol % Fe-doped PZT/NSTO heterostructure demonstrates exceptional resistive switching performance, achieving an on/off ratio of 4.4 × 104 that surpasses undoped samples by 2 orders of magnitude. Systematic characterization reveals a dual-regulation mechanism where oxygen vacancy redistribution and ferroelectric polarization dynamically control the Schottky barrier width at the PZT/NSTO interface. Additionally, the bulk space-charge-limited current behavior synergizes with the interfacial modulation to create a balanced resistance state. Our findings identify an optimal Fe doping concentration that balances oxygen vacancy distribution and polarization charges, thereby improving both interfacial barrier tunability and bulk trap-mediated conduction. These results not only provide insights into the coupling of oxygen vacancies and polarization in perovskite ferroelectrics but also offer a materials design strategy for high-performance RS devices by matching interfacial and bulk resistance through doping.