High-Mobility Transport Anisotropy in Few-Layer MoO₃ and Its Origin

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional semiconductors are crucial for next-generation high-speed, low-power nanoelectronics.
• Metal oxides are explored for electronic applications due to stability, but often have low carrier mobility.
• Existing metal oxides exhibit carrier mobilities far below silicon's performance.

Purpose of the Study:

• To investigate few-layer molybdenum trioxide (MoO3) as a potential high-performance semiconductor.
• To predict the carrier mobility and understand its transport properties using theoretical methods.
• To explore the anisotropy in carrier mobility within few-layer MoO3.

Main Methods:

• Utilized first-principles calculations to model material properties.
• Applied deformation potential theory to analyze carrier mobility.
• Investigated the relationship between electronic structure, elastic properties, and transport anisotropy.

Main Results:

• Predicted few-layer MoO3 as a chemically stable, wide-band-gap semiconductor.
• Calculated acoustic-phonon-limited carrier mobility exceeding 3000 cm² V⁻¹ s⁻¹, suitable for both electron and hole transport.
• Discovered significant in-plane carrier mobility anisotropy (ratio of 20-30) attributed to directional elastic modulus and deformation potential.

Conclusions:

• Few-layer MoO3 exhibits exceptionally high carrier mobility and anisotropic transport properties.
• The findings provide insight into the high mobility observed in MoO3 systems.
• Highlights the critical importance of carrier transport direction for device performance in MoO3-based electronics.