Electronic and Optical Properties of Sodium-Doped BeO Nanotubes from First-Principles

This study explores the effects of sodium (Na) doping on the density of states (DOS) and optical spectra of armchair beryllium oxide nanotubes (aBeONTs) (n, n) (n = 6, 7) exploiting density functional theory (DFT). Initially exhibiting insulating behavior, Na metalizes aBeONTs by introducing additional charge carriers. In addition, the static refractive index values corresponding to the spin-polarized Na-doped a-BeONTs are almost lower than unpolarized Na-doped aBeONTs values due to the polarization-dependent optical spectra of Na-doped aBeONTs. The optical conductivity peaks for sodium-doped nanotubes are observed at 0.5 and 6.5 eV across different polarizations, indicating the influence of the anisotropic properties of the simulated nanotubes. Sodium doping enhances optical absorption, reflectivity, susceptibility, and polarizability, particularly in the lower energy range. These findings highlight the potential of sodium-doped aBeONTs for applications in optoelectronics and nanotechnology.