Single-atom infrared emission in doped silicon nanocrystals

Silicon luminescence, due to silicon being abundant, non-toxic and harmless, is a topic of pivotal importance in optoelectronics and biological imaging. However, a major challenge in developing high-efficiency silicon light sources is the relatively weak allowable transitions. This study focuses on single atom-doped silicon nanocrystals (Si NCs) and theoretically investigates the emission behavior of single atoms within a tetrahedral coordination field. Doping a single atom in Si NCs can result in a ∼10² times improvement at least in the squared transition dipole moment (TDM²), and induce a spectral shift towards near- and mid-infrared wavelengths. These findings offer a strong foundation for designing Si NCs for on-chip optical communication and single photon emitters.