Photochromism in rare earth oxyhydrides for large-area transmittance control

Photochromic coatings are attractive materials for achieving dynamic transmittance control in glazing. However, state-of-the-art photochromic materials are either not durable enough (the case of organic photochromic dyes), or not easily manufactured onto large glass panes (the case of silver halides). The requirements of durability and large area fabrication have hitherto hindered the application of photochromism in smart glazing. Thus, the importance of rare-earth oxyhydrides, which have emerged during the last decade as an inorganic (and hence, in principle, durable) photochromic family of materials that can be prepared onto large area glass panes by magnetron sputtering. In this work, we will discuss in detail the photochromic effect in oxyhydrides, how to prepare and optimize photochromic coatings with excellent switching kinetics, as well as answer other frequently asked questions when it comes to the applications of rare earth oxyhydrides in glazing.