Tuning the conducting types of VSi₂N₄ by van der Waals engineering

Area of Science:

• Materials Science
• Condensed Matter Physics
• Spintronics

Background:

• Vanadium disulfide nitride (VSi2N4) is a promising MA2Z4 material for spintronics.
• Its limited electronic properties, lacking states at the Fermi level, hinder direct applications.
• Van der Waals (vdW) heterostructures offer a route to tune material characteristics.

Purpose of the Study:

• To investigate the electronic modulation of VSi2N4 by forming vdW heterostructures.
• To explore the impact of integrating VSi2N4 with MoS2, graphene, and NbS2.
• To assess the potential for spintronic applications through these heterostructures.

Main Methods:

• First-principles calculations were employed to study the electronic properties of VSi2N4-based heterostructures.
• The study focused on interfaces with MoS2 (semiconductor), graphene (semimetal), and NbS2 (metal).
• Analysis included charge transfer, electronic band structure, and magnetic properties.

Main Results:

• MoS2 integration showed no significant charge transfer or electronic modulation of VSi2N4.
• Graphene integration induced charge transfer in both spin channels.
• NbS2 integration effectively modulated VSi2N4, inducing a half-semiconducting to half-metallic phase transition.
• The VSi2N4/NbS2 heterostructure achieved fully spin-polarized transport and giant tunnel magnetoresistance (~1.15 × 10^4%).

Conclusions:

• NbS2 is a potent material for tuning VSi2N4's electronic states and enabling half-metallic properties.
• VSi2N4/NbS2 vdW heterostructures are highly promising for nanoelectronic and spintronic devices.
• The findings pave the way for advanced spintronic applications using VSi2N4-based materials.