Advancing Stronger Light–Matter Coupling: Tin Nanoantennas as a New Plasmonic Platform

Chemnitz University of Technology researchers uncover a new way to amplify light-matter coupling in graphene using tin nanoantennas, published in “Advanced Optical Materials”

The DFG Research Unit “Proximity-Induced Correlation Effects in Low-Dimensional Structures”, coordinated by Chemnitz University of Technology, investigates how proximity effects and interface engineering in atomically thin materials can be used to design next-generation quantum and optoelectronic devices. The research group explores epitaxial growth and intercalation of heavy carbon-group elements beneath graphene to tune its electronic and optical properties, ultimately forming hybrid systems with enhanced light-matter interaction.

In a recent publication in the renowned journal “Advanced Optical Materials”, researchers from the Professorships of Semiconductor Physics and Analytics on Solid Surfaces at TU Chemnitz reported a breakthrough in coupling light to graphene. Their work introduces tin (Sn) nanoantennas as a new plasmonic material capable of boosting the interaction between light and two-dimensional (2D) systems. This achievement not only expands the palette of plasmonic materials beyond conventional gold and silver but also strengthens graphene’s potential for future applications in molecular sensing, ultrafast photodetectors, and quantum nanophotonic devices.

From challenge to opportunity: how to make graphene absorb more light

2D materials, such as graphene, are highly regarded for their exceptional mechanical, thermal, and electronic properties. Notably, the absence of an energy bandgap in its electronic structure makes graphene particularly well-suited for broadband optical applications, including use in lasers and tunable optical modulators. Despite these remarkable traits, however, these materials interact only weakly with light; monolayer graphene absorbs a mere 2.3% of incident visible light under normal incidence. This low intrinsic absorption has long limited the use in optoelectronics.

One effective strategy to overcome this limitation involves the use of plasmonic nanoantennas, metallic nanostructures that act like tiny optical funnels. Much like a radio antenna concentrates widely spread (far-field) electromagnetic waves into a confined electrical signal, plasmonic antennas efficiently convert incident light into highly localized near-field plasmonic oscillations. This process focuses light into nanoscale “hot spots,” where the electromagnetic fields are dramatically intensified and concentrated far below the diffraction limit of light. Within these confined regions, interactions among electrons, phonons, and molecular vibrations occur much more efficiently, leading to enhanced optical processes such as surface-enhanced Raman spectroscopy (SERS), high-sensitivity photodetection, and photocatalytic energy conversion.

Sn nanoantennas: a new path to strong coupling

In their recent study, researchers from Chemnitz introduced Sn as a novel plasmonic medium. They successfully demonstrated that Sn nanoantennas can amplify the scattering intensity of graphene’s Raman-active phonons by more than two orders of magnitude. "This significant enhancement was achieved by positioning the graphene in dual-sided proximity to Sn nanostructures, which effectively act as plasmonic nanoantennas,” explains Dr. Narmina Balayeva, a postdoctoral researcher at the Professorship of Semiconductor Physics at Chemnitz University of Technology. “Using a technique called confinement epitaxy, a 2D metallic Sn layer first formed naturally between the graphene sheet and its silicon carbide (SiC) substrate, followed by the growth of Sn nanoislands directly on the graphene surface.”

A window into new physics

Enhancing light-matter interaction is not merely about improving device performance; it unveils possibilities to explore new regimes of quantum and optical physics. “When light is confined to dimensions comparable to atomic scales, it can form entirely new hybrid states, so-called polaritons, where electronic and optical excitations become inseparable,” says Dr. Zamin Mamiyev, a postdoctoral researcher at the Professorship of Analytics on Solid Surfaces, who coordinated the experiments. “Under such extreme spatial and optical confinement, we can probe energy-transfer mechanisms and quasiparticle dynamics that remain entirely hidden in conventional, macroscopic measurements. This effectively allows us to push the boundaries of sensing, photonics, and quantum technologies.”

The ability to manipulate and engineer materials one atomic layer at a time has inaugurated a new era of "materials-by-design," with hundreds of stable 2D crystals now available for combination into complex heterostructures. “Through targeted intercalation, inserting specific atoms between layers, we can form unusual material phases that are difficult to achieve otherwise and precisely control how these ultrathin materials interact at their interfaces,” adds Prof. Dr. Christoph Tegenkamp, head of the Professorship Analytics on Solid Surfaces and spokesperson for the DFG Research Unit. “This unprecedented control allows us to fine-tune and probe electronic and photonic interactions at a truly fundamental level, an essential capability for developing the next generation of high-performance quantum technologies.”

Looking ahead

Building on this success, the research team aims to further refine the plasmonic response of the metallic nanoantennas and their interface with graphene. By precisely optimizing these hybrid structures, they intend to achieve even stronger near-field coupling, ultimately paving the way for entirely new classes of quantum materials and functionalities. This work underlines Chemnitz University of Technology’s leading role in advancing research on 2D materials, plasmonics, and quantum nanophotonics, effectively bridging fundamental science and the future technologies that will shape the light-based devices of tomorrow.

Publication: Enhanced Light–Matter Interactions With a Single Sn Nanoantenna on Epitaxial Graphene; Zamin Mamiyev, Narmina O. Balayeva, Dietrich R.T. Zahn, Christoph Tegenkamp; Advanced Optical Materials

DOI:  https://doi.org/10.1002/adom.202500979

For further information please contact Prof. Dr. Christoph Tegenkamp, Telefon 0371 531-33103, E-Mail christoph.tegenkamp@physik.tu-chemnitz.de and Dr. Zamin Mamiyev, Telefon +49 371 531-3170, E-Mail zamin.mamiyev@physik.tu-chemnitz.de

(Source: DFG Research Unit “Proximity-Induced Correlation Effects in Low-Dimensional Structures”)

Mario Steinebach
24.11.2025

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