Impact of interfacial effects on ferroelectric resistance switching of Au/BiFeO3/Nb:SrTiO3(100) Schottky junctions

Direct evidence of purely interfacial effects on resistance switching is demonstrated in Au/BiFeO3/Nd:SrTiO3(001) (Au/BFO/NSTO) Schottky junctions by reducing the thickness of ferroelectric interlayer BFO. The Au/BFO/NSTO junction shows large current rectification and hysteretic resistive switching behavior without any electroforming process. The conduction mechanism is dominated by interface-limited Fowler-Nordheim (FN) tunneling through a potential barrier formed at the BFO/NSTO interface. Measurements of polarization switching dynamics and capacitance-voltage characteristics provide direct evidence that the resistance switching in the Au/BFO/NSTO junction is ferroelectric and interfacially limited. The observed resistance switching behavior can be attributed to the ferroelectric polarization modulation of the barrier and depletion width of the p-n junction formed at the BFO/NSTO interface.