Two-Dimensional Pentagonal Materials with Parabolic Dispersion and High Carrier Mobility

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Graphene's high carrier mobility is limited by its zero band gap, hindering field-effect transistor (FET) applications.
• Parabolic dispersion in materials typically offers high carrier mobility and a suitable band gap.

Purpose of the Study:

• To predict and investigate novel two-dimensional (2D) materials with high carrier mobility and direct band gaps.
• To explore the potential of pentagonal lattice structures for electronic applications.

Main Methods:

• First-principles calculations were employed to study the electronic and mechanical properties of penta-MX2 monolayers.
• The study focused on M = Ni, Pd, Pt and group V elements (X).

Main Results:

• A novel planar pentagonal lattice, penta-MX2, was predicted, exhibiting parabolic dispersion.
• These materials possess a direct band gap (0.551-1.105 eV) and exceptionally high carrier mobility (~1 × 10^8 cm^2 V^-1 s^-1).
• Anisotropic mechanical properties and UV absorption peaks were observed.

Conclusions:

• Penta-MX2 monolayers demonstrate superior carrier mobility compared to graphene, black phosphorene, and other 2D hexagonal materials.
• These 2D materials show promise for experimental exfoliation, especially with nitrogen elements.
• Penta-MX2 monolayers offer new avenues for designing high-performance 2D semiconductor materials.