Silicon coupled with plasmon nanocavities generates bright visible hot luminescence

To address the limitations in device speed and performance in silicon-based electronics, there have been extensive studies on silicon optoelectronics with a view to achieving ultrafast optical data processing(1-3). The biggest challenge has been to develop an efficient silicon-based light source, because the indirect bandgap of silicon gives rise to extremely low emission efficiencies. Although light emission in quantum-confined silicon at sub-10 nm length scales has been demonstrated(4-7), there are difficulties in integrating quantum structures with conventional electronics(8,9). It is desirable to develop new concepts to obtain emission from silicon at length scales compatible with current electronic devices (20-100 nm), which therefore do not utilize quantum-confinement effects. Here, we demonstrate an entirely new method to achieve bright visible light emission in 'bulk-sized' silicon coupled with plasmon nanocavities at room temperature, from non-thermalized carrier recombination. The highly enhanced emission (internal quantum efficiency of >1%) in plasmonic silicon, together with its size compatibility with current silicon electronics, provides new avenues for developing mono-lithically integrated light sources on conventional microchips.