Interband Plasmonic Materials: A promising Platform for Nanophotonics

Abstract

Research in plasmonics and metamaterials has shown ways to manipulate light down to the nanoscale by creating artificial media with properties not available in nature. These fields were first developed using noble metal nanostructures as building blocks, and in the latest years they have been enriched by employing alternative plasmonic materials, such as transparent conducting oxides or metal nitrides.1 The plasmonic response of most of these materials is based on the optical excitation of volume free carriers. However recently plasmonic effects at visible frequencies have been observed in nanostructures made of semi-metals (bismuth2) and chalcogenides (bismuth telluride3, BSTS4). These materials present no optical absorption due to volume free carriers in this spectral region. Nevertheless, they share a common feature with the earlier plasmonic materials: they show a negative bulk dielectric permittivity. In this case, this feature is due to the excitation of strong interband transitions rather than volume free carriers.4,5,6 Therefore, interband polaritons and surface conducting states have been proposed to drive the plasmonic effects observed in the nanostructures. In this presentation, we will describe the optical properties of this new type of so-called ¿interband plasmonic¿ materials in relation with their electronic structure. Their performance will be compared with that of the earlier plasmonic materials, and their potential for the design of active optical metamaterials for switching and sensing applications will be presented. REFERENCES 1. Naik, F. M., Shalaev, V.M. and Boltasseva, A., ¿Alternative plasmonic materials: beyond gold and silver¿ Adv. Mater. 25, 3264, 2013. 2. Toudert, J., Serna, R., and Jime¿nez de Castro, M., ¿Exploring the optical potential of nano-bismuth: tunable surface plasmon resonances in the near-ultraviolet to near-infrared range¿ J. Phys. Chem. C 116, 20530, 2012. 3. Zhao, M. et al., ¿Actively tunable visible surface plasmons in Bi2Te3 and their energy harvesting applications¿, Adv. Mater. 28, 3138, 2016. 4. Ou, J.-Y., So, J.-K., Adamo, G., Sulaev, A., Wang, L., and Zheludev, N.I., ¿Ultraviolet and visible range plasmonics in the topological insulator Bi1.5Sb0.5Te1.8Se1.2¿, Nature Comm. 5, 5139, 2014. 5. Toudert, J., and Serna, R., ¿Ultraviolet-visible interband plasmonics with p-block elements¿, Opt. Mat. Expr. 7, 2434, 2016. 6. Toudert, J., Serna, R., Camps, I., Wojcik, J., Mascher, P., Rebollar, E., and Ezquerra, T.A., ¿Unveiling the far infrared to ultraviolet optical properties of bismuth for applications in plasmonics and nanophotonics¿, J. Phys. Chem. C 121, 3511, 2017.