  The fabrication of flexible single-crystalline plasmonic or photonic
components in a scalable way is fundamentally important to flexible electronic
and photonic devices with high speed, high energy efficiency, and high
reliability. However, it remains to be a big challenge so far. Here, we have
successfully synthesized flexible single-crystalline optical hyperbolic
metamaterials by directly depositing refractory nitride superlattices on
flexible fluoro phlogopite-mica substrates with magnetron sputtering.
Interestingly, these flexible hyperbolic metamaterials show dual-band
hyperbolic dispersion of dielectric constants with low dielectric losses and
high figure-of-merit in the visible to near-infrared ranges. More importantly,
the optical properties of these nitride-based flexible hyperbolic metamaterials
show remarkable stability under either heating or bending. Therefore, the
strategy developed in this work offers an easy and scalable route to fabricate
flexible, high-performance, and refractory plasmonic or photonic components,
which can significantly expand the applications of current electronic and
photonic devices.
