Enhanced visible light absorption and carrier mobility in the type-II Bi₂C₃/GeTe van der Waals heterostructure: a...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) materials offer unique properties but are limited in single layers.
• Van der Waals (vdW) heterostructures enable combining distinct 2D materials to overcome limitations.
• Optoelectronic devices benefit from novel heterostructures with tailored electronic and optical properties.

Purpose of the Study:

• To systematically investigate the structural, electronic, transport, and optical properties of the Bi2C3/GeTe vdW heterostructure.
• To assess the potential of this heterostructure for high-performance optoelectronic applications.

Main Methods:

• First-principles calculations were employed to model and analyze the heterostructure.
• Structural stability, electronic band alignment, mechanical properties, and optical absorption were computationally probed.

Main Results:

• The Bi2C3/GeTe heterostructure is energetically stable, governed by weak vdW forces, and exhibits enhanced in-plane stiffness.
• A type-II band alignment was observed, promoting efficient photogenerated electron-hole separation.
• The heterostructure shows a reduced band gap, broadened visible-light absorption up to 3.50 × 10^5 cm^-1, and high electron/hole mobilities.

Conclusions:

• The Bi2C3/GeTe heterostructure presents a promising candidate for advanced optoelectronic devices due to its robust mechanical properties.
• The combination of efficient charge separation, enhanced visible-light absorption, and superior carrier mobility highlights its application potential.