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Switchable ferroelectric diode and photovoltaic effect in BiFeO3
1Rutgers Center for Emergent Materials and Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, USA.
Science (New York, N.Y.)
|February 21, 2009
Summary
Researchers discovered a diode effect in bismuth ferrite (BiFeO3) crystals, enabling unidirectional electric current flow. This switchable ferroelectric diode exhibits a photovoltaic effect, advancing electronic and optical device design.
Area of Science:
- Solid State Physics
- Materials Science
- Ferroelectricity
Background:
- Unidirectional electric current is crucial for electronic devices, typically achieved at asymmetric interfaces.
- Ferroelectric materials offer potential for novel electronic functionalities due to their switchable polarization.
Purpose of the Study:
- To investigate the diode effect in bismuth ferrite (BiFeO3) associated with its bulk electric polarization.
- To explore the potential of ferroelectric BiFeO3 for switchable electronic and optical devices.
Main Methods:
- Fabrication of diode structures using ferroelectric monodomain BiFeO3 crystals.
- Characterization of bulk electric conduction under varying electric polarization.
- Measurement of photovoltaic effects in the BiFeO3 diode structures.
Main Results:
- Observed highly nonlinear and unidirectional bulk electric conduction in BiFeO3.
- Demonstrated that the diode effect's direction is switchable by external voltage, correlating with electric polarization.
- Reported a substantial visible-light photovoltaic effect in the BiFeO3 diode structures.
Conclusions:
- Established a diode effect originating from the bulk electric polarization in ferroelectric BiFeO3.
- Highlighted the potential for designing novel switchable devices combining ferroelectric, electronic, and optical properties.
- Advanced the understanding of charge conduction mechanisms in leaky ferroelectrics.
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