  Silicon is now firmly established as a high performance photonic material.
Its only weakness is the lack of a native electrically driven light emitter
that operates CW at room temperature, exhibits a narrow linewidth in the
technologically important 1300- 1600 nm wavelength window, is small and
operates with low power consumption. Here, an electrically pumped all-silicon
nano light source around 1300-1600 nm range is demonstrated at room
temperature. Using hydrogen plasma treatment, nano-scale optically active
defects are introduced into silicon, which then feed the photonic crystal
nanocavity to enahnce the electrically driven emission in a device via Purcell
effect. A narrow ({\Delta}{\lambda} = 0.5 nm) emission line at 1515 nm
wavelength with a power density of 0.4 mW/cm2 is observed, which represents the
highest spectral power density ever reported from any silicon emitter. A number
of possible improvements are also discussed, that make this scheme a very
promising light source for optical interconnects and other important silicon
photonics applications.
