In a significant advancement in nano-photonics, researchers have introduced a new approach to achieve flexible near-infrared plasmonic devices using affordable scandium nitride (ScN) films. This could revolutionize the design of future optoelectronic devices, flexible sensors, and medical imaging tools that rely on NIR light, by introducing scalable and cost-effective plasmonic materials

Plasmonics is a field that leverages the interaction between light and free electrons in metals to create extremely confined electromagnetic fields. Traditionally, plasmonic materials have been rigid and possess limited design possibilities. Most of them like gold or silver, tend to be costly and possess limited versatility.

Prof. Bivas Saha at the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bangalore, an autonomous institute under the Department of Science and Technology (DST), demonstrated a method to grow flexible plasmonic structures. They produced ScN layers with exceptional quality and flexibility by pairing scandium nitride with van der Waals layer substrates, materials with weak interlayer interactions, thus introducing a new pathway in plasmonic materials research.

The team used a process by which single-crystal layers are deposited onto a substrate, technically called epitaxial growth. The technique they used stacks layers of materials with weak interlayer bonding to enable new device architecture (van der Waals heteroepitaxy).

The study, recently published in Nano Letters, highlights the potential of scandium nitride as a promising plasmonic material for applications that require both flexibility and precision in near-infrared (NIR) optics.

Through precise engineering, the team achieved high-quality epitaxial ScN layers on flexible substrates, creating conditions where plasmon-polaritons—quasiparticles resulting from the coupling of plasmons with photons—can propagate in the near-infrared range.

Prof. Saha’s team demonstrated that ScN is a stable material that not only supports NIR plasmonics but also retains its performance when subjected to bending and flexing, making it a frontrunner for flexible device applications.

"Scandium nitride’s stability, combined with its compatibility with van der Waals substrates, makes it an exciting candidate for next-generation flexible electronics. Our findings are a step towards realizing advanced plasmonic devices that are not only high-performing but also adaptable to unconventional applications."

This research holds promise for a wide array of industries, from telecommunications to biomedicine, offering a new material foundation for developing next-generation flexible and wearable plasmonic devices. “The results mark a critical step in merging plasmonics with flexible electronics, potentially setting the stage for innovations that leverage the unique properties of near-infrared plasmon-polaritons”-commented Mr. Debmalya Mukhopadhyaya, the first author of this work.

As plasmonics continues to evolve, the innovative use of scandium nitride in Prof. Saha’s research exemplifies the creative potential of materials science and its capacity to redefine technological boundaries.

Publication: https://doi.org/10.1021/acs.nanolett.4c04616

Contact Information: Prof. Bivas Saha (email: bsaha[at]jncasr[dot]ac[dot]in,)