A Versatile Materials Class for Solution‐Processed Optics and Photonics Based On Titanium Oxide Hydrates and Polyalcohols: A Perspective

The ability to propagate light within a structure comprising a controlled spatial distribution of the refractive index n prompted the telecommunications revolution of the 20th century. More recently, progress with exploiting the flow of light has led to a broad range of light- and heat-management tools, as well as novel quantum devices. This perspective discusses a new versatile class of optical materials based on molecular hybrids of metal oxide hydrates and commodity polymers, such as poly(vinyl alcohol). These fascinating, easy-to-produce materials are examined, and their processing into useful architectures such as photonic crystals is reviewed, with a focus on thin-film optics. Their potential in other areas is also assessed, for instance, for the fabrication of optical microcavities that allow the formation of exciton-polaritons, enabling studies on strong light-matter interactions. Generally, these molecular hybrids open future opportunities in applications like optics, photonics, quantum devices, catalysis, and beyond.