Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

1 Publication
Oxyhydride Nature of Rare-Earth-Based Photochromic Thin Films
Cornelius, S.; Colombi, G.; Nafezarefi, F.; Schreuders, H.; Heller, R.; Munnik, F.; Dam, B.;
Thin films of rare-earth (RE)−oxygen−hydrogen compounds prepared by reactive magnetron sputtering show a unique color-neutral photochromic effect at ambient conditions. While their optical properties have been studied extensively, the understanding of the relationship between photochromism, chemical composition, and structure is limited. Here we establish a ternary RE−O−H composition-phase diagram based on chemical composition analysis by a combination of Rutherford backscattering and elastic recoil detection. The photochromic films are identified as oxyhydrides with a wide composition range described by the formula REOxH3−2x where 0.5 ≤ x ≤ 1.5. We propose an anion-disordered structure model based on the face-centered cubic unit cell where the O2− and H− anions occupy tetrahedral and octahedral interstices. The optical band gap varies continuously with the anion ratio, demonstrating the potential of band gap tuning for reversible optical switching applications.

Publ.-Id: 28973 - Permalink