Hyper-doped silicon nanoantennas and metasurfaces for tunable infrared plasmonics

TL;DR

This paper demonstrates the fabrication and experimental validation of hyper-doped silicon nanoantennas and metasurfaces that exhibit tunable infrared plasmonic resonances, enabling potential applications in sensing and thermal imaging.

Contribution

The work introduces all-silicon hyper-doped nano-structures with tunable plasmonic properties in the infrared range, supported by experimental and numerical analysis.

Findings

Achieved tunable plasmon resonance between 2 and 5 μm by adjusting carrier concentration.

Demonstrated strong infrared absorption using silicon-based metasurfaces with nanoscale structures.

Numerical simulations agree with experimental results, providing insights into shape and near-field effects.

Abstract

We present the experimental realization of ordered arrays of hyper-doped silicon nanodisks, which exhibit a localized surface plasmon resonance. The plasmon is widely tunable in a spectral window between 2 and 5 $\mu$m by adjusting the free carrier concentration between 10$^{20}$ and 10$^{21}$ cm$^{-3}$. We show that strong infrared light absorption can be achieved with all-silicon plasmonic metasurfaces employing nano-structures with dimensions as low as 100\,nm in diameter and 23 nm in height. Our numerical simulations show an excellent agreement with the experimental data and provide physical insights on the impact of the nanostructure shape as well as of near-field effects on the optical properties of the metasurface. Our results open highly promising perspectives for integrated all-silicon-based plasmonic devices for instance for chemical or biological sensing or for thermal imaging.