Ultraviolet interband plasmonics down to the vacuum UV with ultrathin amorphous silicon nanostructures
Silicon dominates electronics, optoelectronics, photovoltaics and photonics thanks to its suitable properties, abundance, and well-developed cost-effective manufacturing processes. Recently, crystalline silicon has been demonstrated to be an appealing alternative plasmonic material, both for the inf...
| Autores: | , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/405521 |
| Acceso en línea: | http://hdl.handle.net/10261/405521 |
| Access Level: | acceso abierto |
| Palabra clave: | Plasmonics Vacuum ultraviolet Nanophotonics Amorphous silicon Epsilon-near-zero |
| Sumario: | Silicon dominates electronics, optoelectronics, photovoltaics and photonics thanks to its suitable properties, abundance, and well-developed cost-effective manufacturing processes. Recently, crystalline silicon has been demonstrated to be an appealing alternative plasmonic material, both for the infrared where free-carrier plasmons are enabled by heavy doping, and for the ultraviolet (UV) where plasmonic effects are induced by interband transitions. Herein, we demonstrate that nanostructured amorphous silicon exhibits such so-called interband plasmonic properties in the UV, as opposed to the expectation that they would only arise in crystalline materials. We report optical plasmon resonances in the 100-to-300 nm wavelength range in ultrathin nanostructures. These resonances shift spectrally with the nanostructure shape and the nature of the surrounding matrix, while their field enhancement properties turn from epsilon-near-zero plasmonic to surface plasmonic. We present a vacuum UV wavelength- and polarization-selective ultrathin film absorber design based on deeply-subwavelength anisotropically-shaped nanostructures. These findings reveal amorphous silicon as a promising material platform for ultracompact and room-temperature-processed UV plasmonic devices operating down to vacuum UV wavelengths, for applications including anticounterfeiting, data encryption and storage, sensing and detection. Furthermore, these findings raise a fundamental question on how plasmonics can be based on amorphous nanostructures. |
|---|