The darkening of photochromic materials


Jose Monteros research about the mechanism behind light induced darkening in yttriumoxyhydride is highlighted by the American Physical Society (APS). 

Jose Montero at the division of Solid State Physics reveals that "breathing" of oxygen is the mechanism behind darkening and bleaching in photochromic in yttrium-oxyhydride (YHO). His work shows that oxygen in YHO diffuses put from the lattice during the light induced darkening and that the bleaching of YHO back to the transparent state swiftly occurs in air whereas in inert nitrogen atmosphere YHO stays in the darkened state.