Visualizing Giant Ferroelectric Gating Effects in Large-Scale WSe₂/BiFeO₃ Heterostructures

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Quantum materials heterostructures are key for advanced microelectronics and optoelectronics.
• Integrating diverse quantum material families is challenging but offers expanded applications.
• Perovskite oxides and transition-metal dichalcogenides (TMDs) are highly multifunctional material classes.

Purpose of the Study:

• To demonstrate large-scale integration of perovskite oxides and TMDs.
• To investigate the electronic coupling between bismuth ferrite (BiFeO3) and tungsten diselenide (WSe2).
• To explore the potential for manipulating TMD properties via proximity effects.

Main Methods:

• Epitaxial growth of WSe2 using molecular beam epitaxy.
• Centimeter-scale transfer of WSe2 onto BiFeO3 films.
• Angle-resolved photoemission spectroscopy (ARPES) to probe electronic structure.

Main Results:

• Successful integration of WSe2 (1-3 monolayers) onto BiFeO3.
• Observation of a giant 0.75 eV energy shift in WSe2 electronic structure.
• Demonstration of WSe2 property modulation by BiFeO3 ferroelectric polarization.

Conclusions:

• This work establishes a pathway for integrating complex oxides and TMDs.
• The observed giant energy shift opens new avenues for ferroelectric control of 2D materials.
• Proximity effects offer a promising route for next-generation electronic and optoelectronic devices.