Magneto-tunable photocurrent in manganite-based heterojunctions

Area of Science:

• Condensed Matter Physics
• Materials Science
• Device Physics

Background:

• Correlated electron oxide heterojunctions show promise for novel electronic devices.
• Understanding interfacial properties is crucial but challenging.
• Conventional semiconductor models are insufficient for these complex systems.

Purpose of the Study:

• To investigate the photovoltaic effect in oxide heterojunctions.
• To explore the influence of correlated electron physics on device performance.
• To demonstrate a magneto-tunable photocurrent in a specific heterojunction.

Main Methods:

• Fabrication of a pn junction using La0.7Sr0.3MnO3 (a correlated electron oxide) and SrTiO3 (a semiconductor).
• Application of epitaxial strain to tune material properties.
• Application of a magnetic field to observe magneto-tunable effects.

Main Results:

• A threefold enhancement in photocurrent was observed upon applying epitaxial strain.
• A further 30% increase in photocurrent was achieved with a magnetic field.
• The magneto-tunable effect was found to be dependent on the correlated gap, bandwidth, and temperature.

Conclusions:

• Correlated electron phenomena can be harnessed for novel electronic devices.
• Epitaxial strain and magnetic fields offer tunable control over photocurrent.
• This work provides a framework for designing oxide heterojunctions with tailored photovoltaic properties.