Near-infrared and Mid-infrared Light Emission of Boron-doped Crystalline Silicon

Dislocation loops by implanting boron into silicon and annealing represents an enticing strategy to transform highly inefficient silicon into a luminescent material. However, the emission at telecommunication wavelength suffers from the strong thermal quenching effect, resulting in low efficiency at room temperature.

Here, we applied a new deep cooling process to address this issue. Interestingly, we find that electrons and holes recombine through defects emitting two photons, one in near infrared (NIR, 1.3~1.6 μm) and the other in mid-infrared band (MIR, around 3.5 μm). The PL intensity at NIR increases by three folds when the temperature increases from 77 K to 300K.