Electronic structure and optical properties of single walled ZnSe nanotubes

Based on the first principle calculations with the generalized gradient approximation we investigate the structure, electronic and optical properties of ZnSe single-walled nanotubes (ZnSe-SWNTs). It is found that contrary to the carbon and BN single-walled nanotubes the band gaps of all the ZnSe-SWNTs are independent of the diameters and chirality. Moreover, the optical properties calculations of the dielectric function ε(ω) with different light polarization direction exhibit moderate optical anisotropy. When the light polarization is perpendicular to the zigzag axis, ZnSe-SWNTs seem to exhibit red-shift effect with the increase in diameters. For the light polarization is parallel to the axis, the main peaks of the dielectric spectrum remain unchanged in position and shape for ZnSe-SWNTs of different diameters.