Ultra-thin yttria-stabilized zirconia as a flexible and stable substrate for infrared nano-optics
Infrared (IR) technologies have become increasingly relevant as they offer a wide range of applications, from thermal imaging to chemical and biological vibrational spectroscopy. Substrate materials, such as calcium fluoride and zinc selenide, are commonly used for IR optics. Unfortunately, they are typically fragile, hygroscopic and expensive, thus producing potential problems during device fabrication and in the long-term functional operation. Here, we introduce yttria-stabilized zirconia (YSZ) ceramic as a flexible and stable platform to implement next generation IR nano-optic devices. In particular, we have combined YSZ with metallic nano-structures and graphene to demonstrate new plasmonics, polarizers and transparent heating substrates. The proposed YSZ-based platforms enable high temperature processing that also withstand harsh environments because of its excellent mechanical, thermal and chemical stability. In addition to the functional capability of making foldable and bendable devices, the demonstrated mechanical flexibility offers the possibility of roll-to-roll processing for low cost and large scale fabrication processes. Our work offers compelling evidence that ultrathin YSZ is a unique substrate for IR applications, given all the combined features, including mechanical flexibility, durability, transparency and easy processing, which are not available from other available material alternatives.