Controllable Photovoltaic Effect of Microarray Derived from Epitaxial Tetragonal BiFeO₃ Films

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• The ferroelectric photovoltaic (FePV) effect is crucial for optoelectronic devices.
• Controllable photovoltaic processes in ferroelectric materials are essential for practical applications.

Purpose of the Study:

• To prepare well-ordered microarrays of epitaxially tetragonal BiFeO3 (T-BFO) films.
• To achieve controllable manipulation of the photovoltaic process in T-BFO films.

Main Methods:

• Pulsed laser deposition technique for T-BFO film preparation.
• Conductive atomic force microscopy (CAFM) for observing polarization-dependent photocurrent.
• Band structure analysis to understand the underlying mechanism.

Main Results:

• Successfully prepared well-ordered T-BFO microarrays.
• Directly observed polarization-dependent photocurrent under UV illumination.
• Demonstrated manipulation of the photovoltaic process by controlling ferroelectric polarization and buffer layers.

Conclusions:

• The photovoltaic process manipulation is attributed to the interplay between interface band alignment and depolarization fields.
• This work deepens the understanding of FePV effects in BiFeO3 devices at the microscale.
• Provides a pathway for developing novel data storage and logic switching microdevices.