Influence of Crystal Structure, Encapsulation, and Annealing on Photochromism in Nd Oxyhydride Thin Films

Journal article (2021)

Authors

D. Chaykina ChemE/Materials for Energy Conversion and Storage - AS
F. Nafezarefi ChemE/Materials for Energy Conversion and Storage - AS
G. Colombi ChemE/Materials for Energy Conversion and Storage - AS
S. Cornelius ChemE/Materials for Energy Conversion and Storage - AS
L.J. Bannenberg RID/TS/Instrumenten groep
H. Schreuders ChemE/O&O groep - AS
B. Dam ChemE/Chemical Engineering
Research Group
ChemE/Materials for Energy Conversion and Storage (AS) (TU Delft)
Copyright: © 2021 D. Chaykina, F. Nafezarefi, G. Colombi, S. Cornelius, L.J. Bannenberg, H. Schreuders, B. Dam
DOI: https://doi.org/10.1021/acs.jpcc.1c10521
More Info
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Published Date

2021

Language

English

Faculty

Applied Sciences

Department

ChemE/Chemical Engineering

Research Group

ChemE/Materials for Energy Conversion and Storage

Abstract

Thin films of rare earth metal oxyhydrides show a photochromic effect, the precise mechanism of which is yet unknown. Here, we made thin films of NdH3-2xOx and show that we can change the band gap, crystal structure, and photochromic contrast by tuning the composition (O2-:H-) via the sputtering deposition pressure. To protect these films from rapid oxidation, we add a thin ALD coating of Al2O3, which increases the lifetime of the films from 1 day to several months. Encapsulation of the films also influences photochromic bleaching, changing the time dependency from first-order kinetics. As well, the partial annealing which occurs during the ALD process results in a dramatically slower bleaching speed, revealing the importance of defects for the reversibility (bleaching speed) of photochromism.