Influence of Cation (RE = Sc, Y, Gd) and O/H Anion Ratio on the Photochromic Properties of REO_xH_3-2x Thin Films

Influence of Cation (RE = Sc, Y, Gd) and O/H Anion Ratio on the Photochromic Properties of REO_xH_3-2x Thin Films

Colombi, G. (TU Delft ChemE/Materials for Energy Conversion and Storage)
De Krom, Tom (Student TU Delft)
Chaykina, D. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Cornelius, S. (TU Delft ChemE/Materials for Energy Conversion and Storage)
Eijt, S.W.H. (TU Delft RST/Fundamental Aspects of Materials and Energy)
Dam, B. (TU Delft ChemE/Chemical Engineering)

ChemE/Chemical Engineering

2021

Rare-earth oxyhydride REOxH3-2x thin films prepared by air-oxidation of reactively sputtered REH2 dihydrides show a color-neutral, reversible photochromic effect at ambient conditions. The present work shows that the O/H anion ratio, as well as the choice of the cation, allow to largely tune the extent of the optical change and its speed. The bleaching time, in particular, can be reduced by an order of magnitude by increasing the O/H ratio, indirectly defined by the deposition pressure of the parent REH2. The influence of the cation (RE = Sc, Y, Gd) under comparable deposition conditions is discussed. Our data suggest that REs of a larger ionic radius form oxyhydrides with a larger optical contrast and faster bleaching speed, hinting to a dependency of the photochromic mechanism on the anion site-hopping.

anions
diffusion
hydride
lanthanides
oxide
oxyhydrides
photochromic
positron annihilation

http://resolver.tudelft.nl/uuid:0b125193-94a1-4a19-91fb-a4999acff4f3

https://doi.org/10.1021/acsphotonics.0c01877

2330-4022

ACS Photonics, 8 (3), 709-715

Institutional Repository

journal article

© 2021 G. Colombi, Tom De Krom, D. Chaykina, S. Cornelius, S.W.H. Eijt, B. Dam