Formation of metallic-like nanodomains and vacancy defects in photochromic rare-earth oxyhydride films

The tunable color-neutral photochromic properties of rare-earth oxyhydride films render them promising for applications in smart windows, memory devices, and photo-catalysts. The investigation of the microstructural and electronic structure changes during the photodarkening-bleaching cycles and their relationship with the optical properties deepens our understanding of the photochromic effect and the memory effect (slower bleaching rate upon cycling) in rare-earth oxyhydride films. This thesis explores the nature and evolution of metallic-like domains and vacancy defects during photodarkening and bleaching by in-situ illumination positron annihilation spectroscopy and spectroscopic ellipsometry…