High-κ Wide-Gap Layered Dielectric for Two-Dimensional van der Waals Heterostructures.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Van der Waals heterostructures are crucial for advanced electronic and photonic devices.
• Limited research exists on wide-gap, high-κ layered dielectrics for these structures.

Purpose of the Study:

• To synthesize and characterize a novel 2D layered dielectric material.
• To evaluate its performance in van der Waals devices.

Main Methods:

• Developed a reproducible synthesis method for rare-earth oxyhalide LaOBr.
• Exfoliated LaOBr into a 2D layered material.
• Fabricated van der Waals field-effect transistors using LaOBr as a dielectric.

Main Results:

• LaOBr exhibits a static dielectric constant of 9 and a wide bandgap of 5.3 eV.
• LaOBr-based van der Waals transistors demonstrate high performance with low interface defect concentrations.
• LaOBr serves as an effective dielectric for electrical gating in excitonic devices.

Conclusions:

• LaOBr is a promising wide-gap, high-κ van der Waals dielectric.
• Its synthesis and exfoliation are easily reproducible.
• LaOBr offers versatile functionality for next-generation 2D electronic and excitonic devices.