First-principles calculations of properties for chalcogen (S, Se, Te) doped silicon

Abstract

Abstract In this paper, density-functional theory based methods are utilized to systematically investigate the properties of chalcogens (S, Se, Te) doped silicon at different doping concentration. The calculated crystal structures indicate that Se-implanted Si at concentration of 1.56% show minimum lattice distortion and formation energy. Intermediate band caused by introduction of chalcogen impurities is beneficial to strong optical absorption in the infrared range. The calculations carried out demonstrate that energy band structure and optical absorption coefficient are all associated with the doping concentration. The bandwidth of intermediate band and forbidden energy gap are broadened due to the increase of impurities concentration. The dependence of optical absorption on doping concentration is confirmed by the calculations. The results reveal that S/Se/Te-doped silicon at concentration on the order of 1.04% is probably suitable candidate for intermediate band materials.