New insights into the photochromic mechanism in oxygen-containing yttrium hydride thin films: an optical perspective

Abstract

Oxygen-containing yttrium hydride thin films exhibit a photochromic behavior: transparent thin films switch from a transparent state to a photodarkened state after being illuminated with UV or blue light. This feature has attracted much attention in recent years due to its potential applications in smart fenestration or in any device in which a response to intense light radiation is needed. However, the process responsible for the reversible change of the optical properties upon illumination is still not well understood. The objective of the present work is to shed some light on the photochromic mechanism by using an optical approach. On this basis, the optical properties of oxygen-containing yttrium hydride thin films have been studied by optical spectrophotometry and ellipsometry before (transparent state) and after UV illumination (dark state). According to the observed results, the photochromic optical change of the films can be explained quantitatively by the gradual growth, under illumination, of metallic phases within the initial wide-band gap semiconducting lattice.

arXiv comment5 pages 5 figures

References in corpus (3)

• A new thin film photochromic material: Oxygen-containing yttrium hydride
• Transparent yttrium hydride thin films prepared by reactive sputtering
• Synthesis of photochromic oxygen-containing yttrium hydride

Cited by in corpus (8)

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• Correlating chemical composition and optical properties of photochromic rare-earth oxy-hydrides using ion beam analysis
• Optical properties of oxygen-containing yttrium hydride thin films during and after the deposition
• Theoretical Design of Effective Multilayer Optical Coatings Using Oxyhydride Thin Films
• Vibrational properties of photochromic yttrium oxyhydride and oxydeuteride thin films
• Role of hydrogen dynamics and deposition conditions in photochromic YHO/MoO${}_3$ bilayer films
• Growth-controlled photochromism in yttrium oxyhydride thin films deposited by HiPIMS and pulsed-DC magnetron sputtering
• Hydrogen partial pressure as a key parameter in the reactive sputtering of photochromic YHO thin films