Two-dimensional GeS with tunable electronic properties via external electric field and strain

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Germanium sulfide (GeS) monolayer, an isoelectronic analog of phosphorene, has emerged as a material with significant potential.
• Recent advancements in synthesis, including vapor deposition and one-pot strategies, have enabled experimental realization of GeS nanosheets.

Purpose of the Study:

• To investigate the stability and electronic properties of GeS monolayer using first-principles calculations.
• To explore methods for tuning the electronic band gap of GeS monolayer through external stimuli.

Main Methods:

• Comprehensive first-principles calculations were employed to study GeS monolayer.
• The effects of external electric fields and in-plane strain (both uniaxial and biaxial) on the electronic band gap were systematically analyzed.

Main Results:

• GeS monolayer exhibits sensitivity to external electric fields, with a semiconductor-to-metal transition observed under sufficient field strength.
• The electronic band gap of GeS monolayer increases approximately linearly with both compressive and tensile strains (-10% to 10%).
• Biaxial strain effects on the band gap mirror those of uniaxial strain along the zigzag x-direction.

Conclusions:

• External electric fields and strain offer effective and straightforward routes to modulate the electronic properties of GeS monolayer.
• These findings facilitate the rational design and development of novel two-dimensional GeS-based electronic devices.