Structural and electronic properties of collapsed armchair single-walled a-graphyne nanotubes

The properties of radially collapsed armchair single-walled a-graphyne nanotubes (a-SWGNTs) are investigated using density functional theory with van der Waals (vdW) corrections. Here, our main goal is to study the structural properties of stable collapsed SWGNT forms and how the corresponding electronic structure are modified in comparison to the circular counterparts. The presence of carbon atoms with sp and sp2 hybridization makes the SWGNTs to present an intriguing geometry for their cross section in the collapsed form and, as a result, the electronic structure of these system is sensitivity to the stacking mode between layers. We find a threshold diameter (26 & ANGS;) for which the collapsed structure is more stable than the circular phase, indicating that the natural form of large SWGNTs is radially collapsed. Furthermore, we identified that the collapsed structure is semiconductor when the diameter of the circular phase is greater than 19 & ANGS;, with band gap values adjusted by the type of stacking between layers. We believe these results can open up possibilities of using such structures in the setups of nanoelectronic device, and provide a basis for future experimental and theoretical research about collapsed graphyne nanotubes.

Automated summary

The properties of radially collapsed armchair single-walled a-graphyne nanotubes (a-SWGNTs) are studied using density functional theory with van der Waals (vdW) corrections. The main goal is to investigate the structural properties and modified electronic structure of stable collapsed SWGNT forms in comparison to circular counterparts. The results show that the collapsed structure is more stable than the circular phase when the diameter exceeds a threshold value, and the collapsed structure exhibits semiconductor behavior with band gap values influenced by the stacking between layers. These findings open up possibilities for the use of collapsed graphyne nanotubes in nanoelectronic devices and provide a basis for further experimental and theoretical research.