Nanotube Structure of AsPS_4-Se (x = 0, 1)

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Chemistry

Background:

• Single-walled nanotubes offer unique electronic and structural properties.
• Arsenic phosphorus chalcogenides are potential candidates for novel electronic materials.

Purpose of the Study:

• To synthesize and characterize single-walled arsenic phosphorus sulfide (AsPS4) and selenide (AsPS3Se) nanotubes.
• To investigate the structural, electronic, and optical properties of these nanotubes.

Main Methods:

• Solid-state reaction for nanotube synthesis.
• Single-crystal X-ray diffraction for structural determination.
• 31P solid-state NMR spectroscopy and optical absorption spectroscopy for property analysis.

Main Results:

• AsPS4 nanotubes were successfully synthesized with an outer diameter of ~1.1 nm.
• Substitution with selenium (AsPS3Se) resulted in amorphous materials, hindering structural determination.
• AsPS4 exhibited a band gap of 2.7 eV and a bulk conductivity of 3.2 × 10^-6 S/cm.
• A negative photoconductivity effect was observed in AsPS4 under illumination.

Conclusions:

• Single-walled AsPS4 nanotubes possess semiconducting properties with conductivity attributed to hopping through trap states.
• The incorporation of selenium disrupts nanotube formation, leading to amorphous structures.