Compatibility between Schottky-Mott Limit and High Carrier-Injection Efficiency in Metal-van der Waals Semiconductor...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Traditional bulk junctions exhibit Fermi level pinning (FLP), limiting Schottky barrier height (SBH) tunability.
• This FLP phenomenon extends to 2D van der Waals (vdW) semiconductors, posing challenges for device performance.

Purpose of the Study:

• To investigate the persistence of FLP in ideal metal-vdW semiconductor junctions (MVSJs).
• To reconcile experimental observations of ideal MVSJs with the theoretical Schottky-Mott limit (SML).

Main Methods:

• Theoretical analysis of wave function hybridization at the metal-semiconductor interface.
• Modeling the impact of interfacial distance on metal-semiconductor interactions.

Main Results:

• Intrinsic FLP is shown to persist in stable ideal MVSJs due to wave function hybridization.
• Achieving the SML and high interface current simultaneously is prevented by FLP.
• Decreasing metal-semiconductor interactions to reduce FLP increases contact resistance and degrades charge injection.

Conclusions:

• Wave function hybridization is a key factor causing FLP in ideal MVSJs.
• Simultaneously achieving SML and high interface current remains a significant challenge.
• Further experimental investigation is crucial for understanding and overcoming FLP in 2D semiconductor interfaces.