Temperature stability of individual plasmonic Au and TiN nanodiscs

Abstract

Refractory plasmonic materials are of interest for high-temperature plasmonic applications due to their increased thermal stability when compared to gold and silver. Titanium nitride (TiN) has been highlighted as a promising refractory material, offering both strong plasmonic and thermal performance. In this work, we analyze the stability of both the structural and optical response of individual plasmonic nanodiscs of various diameters subjected to elevated temperature conditions in air. Using cathodoluminescence spectroscopy, we trace the resonance spectra and shape modifications of the same single TiN and Au discs annealed at increasing temperatures up to 325 °C. TiN discs display greater morphological stability, but the optical properties of both materials deteriorate from 200 °C, although the mechanisms of degradation are different. The results are essential for optimizing nanostructured materials for high temperature nanophotonic applications.