First-principles calculations to investigate electronic structures and optical properties of chalcogens-hyperdoped silicon

The properties of chalcogens doped silicon with different atomic structures are systematically investigated using first-principles. The calculated results show that substitutional structure exhibit best thermal stability and hexagonal interstitial is metastable structure. All configurations can introduce intermediate-band (IB) related to the impurity and lead to the below-band-gap absorption. Combining the optical properties with the formation energy calculations, we infer the high concentration of substitutional doping in Te-doped silicon prepared by fs-irradiating Si surface in the presence of chalcogens thin film will lead to it is more resistant to thermal annealing than S- and Se-doped Si as observed in experiments.