Violet emission from bulk Si prompted by surface plasmon polaritons

TL;DR

This paper reports the discovery of efficient violet light emission from bulk silicon at room temperature, facilitated by surface plasmon polaritons at the SiO/Si interface, opening new avenues for silicon-based light sources.

Contribution

It demonstrates that surface plasmon polaritons can induce violet emission in bulk silicon, a novel mechanism for silicon photoluminescence at room temperature.

Findings

Violet emission at 368 nm observed from bulk silicon.

Emission linked to surface plasmon polaritons at the SiO/Si interface.

Potential for silicon-based violet light sources.

Abstract

Silicon has been long known as a poor light emitter due to its indirect band gap and strong phonon-assisted decay of the excited states. Nevertheless, we have revealed efficient quasi-monochromatic photoluminescence at 368 nm from bulk silicon in the near-violet spectral range of the interband transition SiE{\Gamma}1 even at room temperature. Optical and electron spectroscopy experiments showed a clear relation of the emission to a surface plasmon polariton (SPP) located on the SiO/Si interface. The presented results demonstrate that the unveiled luminescence is an effect of creation and decay of the SPP being a mixture of the surface plasmon, light, and the bulk interband transition. The SPP evolves in the silicon layer with a thickness of the order of the near-violet wave penetration depth (~80 nm) and is characterized by high excitation amplitude due to its hybrid nature. The effect seems to be easily applicable in developing near-violet light sources based on the existing Si-technology.