Obtaining bright visible light emission from “Bulk” silicon by nanocavity plasmons

Abstract form only given. Due to limitations in device speed and performance of silicon-based electronics, silicon optoelectronics has been extensively studied to achieve ultrafast optical-data processing. However, the biggest challenge has been to develop an efficient silicon-based light source since indirect band-gap of silicon gives rise to extremely low emission efficiency. Although light emission in quantum-confined silicon at sub-10 nm lengthscales has been demonstrated, there are difficulties in integrating quantum structures with conventional electronics. It is desirable to develop new concepts to obtain emission from silicon at lengthscales compatible with current electronic devices (30-100 nm), and therefore cannot use quantum-confinement effects. Recently, we demonstrated enhancement of radiative recombination rates by a factor of 1000 by coupling semiconductors to optimized plasmonic nanocavities. We have now utilized this concept to demonstrate an entirely new method to achieve bright visible light emission in “bulk-sized” silicon coupled with plasmon nanocavities from non-thermalized carrier recombination via Purcell enhancement. Highly enhanced emission quantum efficiency (>1%) in plasmonic silicon, along with its size compatibility with present silicon electronics, provides new avenues for developing monolithically integrated light-sources on conventional microchips.