Electronic and optical properties of P-substituted tellurene nanoribbons: first principles study

We propose a quasi-one-dimensional P-substituted tellurene nanoribbon (TeNR) (with sizes ranging from 7 to 5 Å) based on a β-Te monolayer configuration using the first principles of density functional theory (DFT) calculations. This system appears to have outstanding electronic and optical properties as revealed by its energy band structure, density of state (DOS), and optical spectrum. P-substituted TeNR has lower formation energy than that of pristine TeNR, indicating that it is more stable than the pristine TeNR. In the presence or absence of the spin–orbit coupling (SOC), P-substituted TeNRs were semiconductors and their direct bandgaps decrease with increasing bandwidth. The DOS and projected DOS are mainly derived from the contributions of the p orbital electrons of Te and P atoms. The dielectric functions of P-substituted TeNRs exhibited optical anisotropy. The absorption spectrum is selective for the incident light energy, and an absorption peaks in the visible and ultraviolet regions indicate that P-substituted n-TeNRs could not only harvest considerable visible light but also capture ultraviolet light, and the peaks also have a trend of red-shift. These findings on quasi-one-dimensional Te nanostructures effectively extend the realm of group VI elements.