Broadband Tunable Infrared Light Emission from Metal-Oxide-Semiconductor Tunnel Junctions in Silicon Photonics

Broadband near-infrared light emitting tunnel junctions are demonstrated with efficient coupling to a silicon photonic waveguide. The metal oxide semiconductor devices show long hybrid photonic-plasmonic mode propagation lengths of approximately 10 μm and thus can be integrated into an overcoupled resonant cavity with quality factor Q ≈ 49, allowing for tens of picowatt near-infrared light emission coupled directly into a waveguide. The electron inelastic tunneling transition rate and the cavity mode density are modeled, and the transverse magnetic (TM) hybrid mode excitation rate is derived. The results coincide well with polarization resolved experiments. Additionally, current-stressed devices are shown to emit unpolarized light due to radiative recombination inside the silicon electrode.