Theoretically proposed stable polymorph of two-dimensional pentagonal β-PdPSe

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Materials Science

Background:

• Two-dimensional (2D) penta materials offer unique properties.
• Penta-NiPS (α and β phases) are theoretically proposed stable 2D materials.
• Experimentally synthesized penta-PdPSe (α phase) shares structural similarities with penta-NiPS.

Purpose of the Study:

• To propose and investigate the β phase of penta-PdPSe as a new, stable 2D material.
• To analyze the stability, electronic, and mechanical properties of β phase penta-PdPSe.
• To compare the properties of β phase penta-PdPSe with its α phase counterpart.

Main Methods:

• First-principles calculations were employed for theoretical discovery and analysis.
• Comprehensive stability analyses (thermodynamic, dynamic, mechanical, thermal) were performed.
• Electronic band structure, Young's modulus, and optical absorption coefficients were calculated.

Main Results:

• The β phase of penta-PdPSe was confirmed to be thermodynamically, dynamically, mechanically, and thermally stable.
• β phase penta-PdPSe is a wide band gap semiconductor with an indirect band gap of 1.58 eV.
• The material exhibits soft mechanical properties and acceptable optical absorption for nanodevices.

Conclusions:

• The β phase of penta-PdPSe is a stable and promising new 2D material.
• Its electronic and optical properties make it suitable for applications in electronic and optical nanodevices.
• This discovery expands the family of stable penta-2D materials.