A first-principles study of structural and electronic properties of α-Te tubular nanostructures
Yanrong Guo1, Songyou Wang1, Yu Jia2, Wan-Sheng Su3*
1Optical Science and Engineering, Fudan University, Shanghai, China
2School of Physics and Engineering, Zhengzhou University, Zhengzhou, China
3Promotion Division, National Taiwan Science Education Center, Taipei, Taiwan
* Presenter:Wan-Sheng Su, email:wssu@mail.ntsec.gov.tw
We employ density functional theory to investigate the structural and electronic properties of α-Te tubular nanostructures. These α-Te tube-like structures, which are similar to carbon nanotubes in terms of their armchair and zigzag structures, are semiconductors with moderate band gaps. The nanotubes in armchair configurations have an indirect-to-direct band gap transition as tube diameter is decreased to a specific critical tube size, while those in zigzag configurations are always semiconductors with a direct gap independent of tube diameter. The calculated projected density of states reveals that such an indirect-to-direct band gap transition found in armchair nanotubes can be attributed to the contributions of the different p-orbitals near the valence band maximum edges. These findings are not only helpful for better understanding the physical characteristics of α-Te nanotubes, but also opening up new possibilities for use in device applications.

Keywords: α-Te nanotubes, first-principles calculations, band gap, density of states