Two-dimensional hydrogenated buckled gallium arsenide: an ab initio study.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Two-dimensional (2D) materials offer unique electronic and structural properties.
• Gallium arsenide (GaAs) is a crucial III-V semiconductor with potential for 2D applications.
• Hydrogenation is a surface modification technique that can alter material properties.

Purpose of the Study:

• Investigate the stability, structural, and electronic properties of hydrogenated 2D GaAs.
• Explore the influence of different geometric configurations (chair, zigzag-line, boat) on 2D H-GaAs.
• Assess the impact of van der Waals interactions on the material's characteristics.

Main Methods:

• First-principles calculations were employed to model 2D H-GaAs systems.
• Density Functional Theory (DFT) with PBE and HSE functionals was used.
• Van der Waals (vdW) interactions were incorporated to study their effect.

Main Results:

• All investigated configurations (chair, zigzag-line, boat) of 2D H-GaAs are energetically and dynamically stable with semiconducting behavior.
• Hydrogenated 2D GaAs exhibits tunable bandgaps, wider than pristine 2D GaAs, with potential for direct and indirect semiconducting properties.
• DFT-vdW interactions qualitatively confirm PBE results on stability and electronic properties, increasing adsorption energies and reducing equilibrium distances.

Conclusions:

• 2D buckled gallium arsenide is a promising material for synthesis via hydrogen surface passivation, analogous to 2D gallium nitride and boron nitride.
• Hydrogenation effectively tunes the bandgap of 2D GaAs, indicating its potential for optoelectronic applications in the blue and violet spectrum.
• The metastability of different configurations suggests flexibility in achieving desired electronic properties through controlled hydrogenation.