Structural stability of single-layer PdSe₂ with pentagonal puckered morphology and its nanotubes

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Materials Science

Background:

• Two-dimensional (2D) materials possess unique properties crucial for future technologies.
• Computational design and discovery are vital for identifying new 2D materials.
• Assessing the stability of predicted 2D materials is a significant challenge.

Purpose of the Study:

• To investigate the structural stability of recently proposed pentagonal 2D materials.
• To analyze the stability of single-layer palladium diselenide (PdSe2) and its nanotubes.
• To explore the potential of PdSe2 for optoelectronic applications.

Main Methods:

• First-principle calculations were employed to assess structural stability.
• Analysis of mechanical stress and interatomic forces in pentagonal nanostructures.
• Calculation of relative energies for PdSe2 monolayer and nanotubes.
• Investigation of electronic band structures for PdSe2 nanotubes.

Main Results:

• PdSe2 nanoclusters exhibit planar structural stability due to optimal Pd sublattice orientation.
• Other pentagonal 2D materials show instability due to excessive interatomic forces.
• The planar PdSe2 monolayer is confirmed as the global energy minimum.
• (n,0) PdSe2 nanotubes are indirect band gap semiconductors, while (n,n) tubes show tunable band gaps.

Conclusions:

• PdSe2 is a stable 2D material with potential for technological applications.
• The planar structure of PdSe2 is key to its stability.
• PdSe2 nanotubes are promising candidates for optoelectronic devices due to their tunable electronic properties.