Structural, electronic, and optic properties of Se nanotubes

A new category of tubular nanostructures solely composed of selenium was explored by using the density functional theory. Similar to those in carbon nanotubes, the armchair and zigzag tube-like structures formed as a roll-up alpha-Se nanoribbon. The zigzag (n <= 16, 0) nanotubes exhibit decreasingly narrow direct band gap, and the armchair (n, n) possess decreasingly moderate indirect gap. The strain energy of nanotubes is inversely pro-portional to the second power of the nanotube diameter. With increasing tube diameter, an initial rise and consequent decrease occurred in the effective masses to the limit value of alpha-Se monolayer. The carrier mobility of nanotubes is comparable with that of its monolayer with orders of 10(3) and 10(2) cm(2)V(-1)s(-1) for electron and hole, respectively. The optical absorption spectra of alpha-Se nanotubes exhibit high absorbance in energy window cover the entire visible light spectrum. Therefore, alpha-Se nanotubes hold great potential for future applications in high-performance optoelectronics.

Automated summary

A new category of tubular nanostructures solely composed of selenium was explored using density functional theory, leading to the discovery that α-Se nanoribbons can form zigzag and armchair tube-like structures. The strain energy of nanotubes is inversely proportional to the square of the diameter, and carrier mobility shows some differences compared to monolayers, but exhibits good optical absorption properties.