Electronic and optical structural manipulation of NbS₂ defects under strain: first-principles calculations

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Monolayer Niobium Disulfide (NbS2) is a novel 2D material with potential in nanodevices and photovoltaics.
• Developing effective synthesis and property tuning methods for NbS2 is crucial for its practical applications.

Purpose of the Study:

• To investigate the strain effects on the electronic and optical properties of sulfur-deficient NbS2.
• To explore the potential of NbS2 as a semiconductor material for advanced electronic applications.

Main Methods:

• First-principles simulations using the CASTEP module within Materials Studio.
• Employing the Perdew-Burke-Ernzerhof (PBE) generalized gradient approximation (GGA) with spin-orbit coupling (SOC) and Van der Waals correction.
• Modeling NbS2 structures under various strain conditions and defect states with detailed computational parameters.

Main Results:

• All investigated defect structures introduce impurity states, enhancing electron transport in NbS2.
• Sulfur-deficient NbS2 with disulfide defects exhibits an indirect band gap (up to 0.56 eV) under tensile strain, qualifying it as a diluted semiconductor.
• Hybrid NbS2 structures demonstrate high transparency across infrared, visible, and low-frequency ultraviolet light, improving transmittance, optical response, and catalytic activity.

Conclusions:

• Sulfur deficiency and tensile strain are effective strategies for tuning the electronic and optical properties of monolayer NbS2.
• The observed semiconductor behavior and enhanced optical properties position NbS2 as a promising material for future nanodevices and photovoltaic technologies.
• This research provides a foundational understanding for further exploration and application of single-layer NbS2.