Room temperature near-infrared electroluminescence of Si/CaF2 quantum cascade laser structures grown on an SOI substrate

Room temperature near-infrared electroluminescence (EL) from Si/CaF2 quantum cascade laser structures has been demonstrated. The structure was equipped with 25 periods of the active region comprised of Si/CaF2 multi quantum-wells and single-mode waveguide grown by molecular beam epitaxy-based technique on the silicon-on-insulator (SOI) substrate. EL spectra with multiple peaks around the near-infrared region were obtained at room temperature and the EL intensity response with injection current clearly confirmed the EL emission was originated from the current injection. Moreover, it was found that EL peak shift by changing applied bias was reasonably explained by energy shift due to the electric field applied to the Si quantum-well of the active region.