Enhancement of room temperature sub-bandgap light emission from silicon photonic crystal nanocavity by Purcell effect

In this work we report on the enhancement of sub-bandgap photoluminescence from silicon via the Purcell effect. We couple mission from silicon, which is believed to be due to hydrogenin corporation in to the lattice, to a photonic crystal (PhC) nanocavity. We observe an up to 300-fold enhancement of the emission at room temperature at 1550 nm, as compared to an unpatterned sample, which is then comparable to the silicon band-edge emission. We discuss the possibility of enhancing this emission even further by introducing additional defects by ion implantation, or by treating the silicon PhC nano cavity with hydrogen plasma.