Structural, electronic, and optical properties of α-Te tubular nanostructures: A first-principles study

• Main Authors: Yanrong Guo, Songyou Wang, Yu Jia, Wan-Sheng Su
• Format: Article
• Language: English
• Published: AIP Publishing LLC 2019-03-01
• Series: APL Materials
• Online Access: http://dx.doi.org/10.1063/1.5087441

We employed density functional theory to investigate the structural, electronic, and optical 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 bandgaps. The nanotubes in armchair configurations have an indirect-to-direct bandgap 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 bandgap transition found in armchair nanotubes can be attributed to the contributions of the different p-orbitals near the valence band maximum edges. The optical absorption spectra of α-Te nanotubes are found to be anisotropic and vary with the tube diameters. 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.