Optical properties of defected silicene: the many-body approach

The electronic structure and excitonic optical properties of pristine and defected silicene are investigated within many-body Green's function and Bethe-Salpeter equation formalism. We show that compared with pristine one, defects can significantly alter band structure and form much better metallic characteristics. Also, it is shown that low defects in pristine silicene can considerably alter optical absorption peaks and change these peaks to the lower energies. Such effect is illustrated for 5 % defects in the pristine silicene and two main peaks in the optical spectrum are shown, one in low energies and another wider one in the higher energies. These peaks can be used as a tool to define the existence of defects and predict the amount of them in experiments. [GRAPHICS] .