Photochromism and photoconductivity in rare-earth oxyhydride thin films

The uncommon photochromism, photo-conductivity, and H-mobility of RE oxyhydride materials make them promising candidates for application in optics, opto-electronics and electrochemical devices alike. Additionally, their extreme compositional flexibility and the connected variety of possible (meta)stable phases make them an excellent case study to advance our understanding of the link between composition, structure, and properties in mixed-anion materials. Further, the possibility of producing RE oxyhydride not only under thermodynamic control (e.g., high temperature/pressure solid state reaction) but also under kinetic control (e.g., topochemical anion-exchange, or post-oxidation of reactively sputtered polycrystalline/epitaxial REHx thin films) largely expands the possibility of tuning their properties, influencing other aspects such as concentration of defect, material morphology, film texture, filmstress, etc.