Silicon coupled with plasmon nanocavities generates bright visible hot luminescence

Abstract

Due to limitations in device speed and performance of silicon-based electronics, silicon optoelectronics has been extensively studied to achieve ultrafast optical-data processing1–3. 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 demonstrated4–7, there are difficulties in integrating quantum structures with conventional electronics8,9. It is desirable to develop new concepts to obtain emission from silicon at lengthscales 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 from non-thermalized carrier recombination. 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.

Enhanced second-harmonic generation from metal-integrated semiconductor nanowires via highly confined whispering gallery modes

“…Besides the high in-coupling efficiency under TM excitation, the in-coming FW is concentrated strongly in the nonlinear region (compared with TE-polarized mode) at the resonant wavelength with perfect overlap, which is crucial to optimize the SHG signal. In contrast, the transverse SPR mostly localizes the optical field in the interlayer 27 (SiO 2 , with negligible nonlinear coefficients; Fig. 4d), which results in poor mode overlap and lower average intensity in the CdS (with very high nonlinear coefficients) region in comparison with TM excitation.…”

“…Here, we report a hybrid metal-semiconductor nanostructure 23,26,27 , that is, a Ag-coated CdS NW, in which CdS has a large nonlinear coefficient of B78 pm V À 1 (42 times larger than lithium niobate) 28 , to engineer highly confined lowest-order WGM, which is used to facilitate tunable, directional and efficient SHG output. We chose the diameter of CdS NWs in the 4150-nm range in order to optimize the SHG signal output while also optimizing their waveguiding properties to enable their applications in nanophotonic circuitry.…”

Optics in Nanotechnology

“…The high fields afforded by plasmonic nanometal material can cause distortion and modification of the crystal structure, hence the interaction with light [48][49][50]. We describe briefly an architecture that demonstrates some of these effects.…”

Near‐Infrared‐Plasmonic Energy Upconversion in a Nonmetallic Heterostructure for Efficient H2 Evolution from Ammonia Borane

“…This is mainly due to their unique capability to concentrate and amplify the incident light intensity near the surface of plasmonic nanostructures 1, 2, 3. As a classic plasmonic “optical antenna,” noble metal nanostructures with tunable LSPR energy are frequently introduced into nanomaterials to promote their performance in light absorption and/or emission via plasmonic energy transfer from noble metal to neighboring optical nanomaterials 4, 5, 6. For example, coupling appropriate nanostructures of plasmonic Au or Ag with upconversion nanomaterials, in particular trivalent lanthanide ions (Ln 3+ )‐doped NaYF 4 nanoparticles (NPs), can achieve enhanced upconversion luminescence in the visible light region by converting lower frequency incident photons at 980 nm with high effectivity 7, 8, 9.…”