Fabrication of Magnetically Tunable Schottky Diode Using Bismuth Ferrite Thin Film on Gold

Gold (50 nm)/bismuth ferrite (BFO) (100 nm) metal-semiconductor Schottky junction is fabricated using pulsed laser deposition (PLD) method on a Si substrate. BFO (BiFeO
₃
) target for PLD deposition was made using BFO nanoparticles synthesized through sol-gel method. The forward- and reverse-bias current-voltage (I-V) characteristics of Au/BFO junction exhibit rectifier characteristics. The threshold voltage (V
_γ
) is 0.3 V which is in agreement with that of a conventional Schottky diode. I-V measurements were done with and without dc magnetic fields (H) to show the tuning of threshold voltage and forward-bias diode current. I-V characteristic shows distinct hysteresis behavior indicating hysteretic switching. Further, the fabricated diode was used as a half-wave rectifier. It has been demonstrated that the Au/BFO Schottky diode is a better high-frequency signal processing diode in comparison to a normal p-n junction silicon diode. Output waveforms were taken over a range of frequencies for both Au/BFO and Si diodes. An Si diode cannot rectify above 10 kHz, whereas Au/BFO junction diode can rectify even up to 1-MHz frequency. At high-frequency, Au/BFO diode exhibits “capacitor filtering effect,” resulting in higher dc voltages.