Room temperature all-silicon photonic crystal nanocavity light emitting diode at sub-bandgap wavelengths

TL;DR

This paper demonstrates a room-temperature, electrically pumped all-silicon nanocavity light emitter operating at sub-bandgap wavelengths with narrow linewidth and high spectral power density, advancing silicon photonics applications.

Contribution

It introduces a novel all-silicon nano light source with defect engineering and Purcell enhancement, achieving record spectral power density at room temperature.

Findings

Narrow emission line at 1515 nm with 0.5 nm linewidth

Power density of 0.4 mW/cm² achieved

Highest spectral power density reported for silicon emitters

Abstract

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.