Electrostatic Gating-Dependent Multiple Band Alignments in Ferroelectric α-In₂Se₃/α-Te van der Waals...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) ferroelectric van der Waals (vdW) heterojunctions are promising for next-generation memory devices.
• Their noncovalent bonding and flexible stacking enable diverse material combinations.
• Emerging ferroelectric memory materials benefit from vdW heterostructures.

Purpose of the Study:

• Investigate the stable geometry and electronic structure of the α-In2Se3/α-Te vdW heterostructure.
• Explore the effects of polarization reversal on the heterostructure's electronic properties and band alignment.
• Analyze the impact of external electric fields on the heterostructure's band structure and alignment.

Main Methods:

• First-principles calculations were employed to study the α-In2Se3/α-Te heterostructure.
• Van der Waals (vdW) correction was incorporated using the DFT-D2 method.
• Modulation effects of external electric fields were analyzed.

Main Results:

• Polarization reversal in α-In2Se3 induces a metallic-to-semiconductor transition in the heterostructure.
• Band alignment shifts from type-III to type-I due to changes in interfacial charge transfer.
• External electric fields tune the band gap and induce transitions to type-II band alignment.

Conclusions:

• The α-In2Se3/α-Te heterostructure exhibits tunable electronic properties and band alignments.
• These tunable properties are crucial for applications in ferroelectric memory and static gate devices.
• The study provides valuable insights for designing advanced electronic devices based on 2D vdW heterostructures.