CdS/CdSe core/shell nanowire as cold anti-reflectors and high voltage nanodevices: A first principles study.

A density functional theory (DFT) based computation was conducted to study the electronic band structure, electron density of states (DOS) and partial DOS of CdS/CdSe core/shell nanowires (NW). The band structure calculation shows a direct bandgap of approximately 2.07eV at the Γ-point, using generalized gradient approximation (GGA). The TDOS and PDOS calculations predict that a sharp peak is obtained at -9 eV below the Fermi level, in the valence band (VB) due to the possible hybridization between Se-p, S-p and Cd-s orbitals. Also, the total DOS calculations predict that the conduction band (CB) are mainly dominated by the Cd-s orbitals. Static dielectric constant and refractive index are 2.46 and 1.57 respectively. Absorption spectra show high absorption in the C band of the UV region with a peak at 8.04 eV. The maximum reflectivity of around 24% occurs at around 8.22 eV. And the low values of reflectivity suggests their possible applications as cold anti-reflectors. [ABSTRACT FROM AUTHOR]