Theoretical Design of Effective Multilayer Optical Coatings Using Oxyhydride Thin Films

Abstract

Rare‐earth metal oxyhydride compositions are currently attracting increasing attention to develop materials with unusual optical responses. Herein, using computer simulations of the electronic and optical properties, the optical responses of two stable yttrium oxyhydride compounds, normalY4normalH10O and YHO, are studied for the visible light range. The emphasis is on modeling macroscopic optical characteristics, which are numerically derived within a conventional scheme using refractive indices, and absorption, transmittance, and reflection spectra. The main goal is twofold: first, to simulate spectral behavior of different single‐phase and two‐phase oxyhydride compositions and second, to conduct a comparative analysis that could explain the features of the transmission spectra measured for different samples. Based on the obtained results, models of new optical coatings are proposed in which yttrium oxyhydrides play the key role. In the context of nonlinear optics, the frequency profile of the second‐order susceptibility χ(2)(2ω) for the noncentrosymmetric cubic structure of normalY4normalH10O is evaluated and it is shown that this system could exhibit large optical nonlinearity.

Experimental and Theoretical Investigation of Gadolinium Oxyhydride (GdHO) Thin Films: Optical, Photocatalytic, and Electronic Properties

“…Through ion beam analysis, these theoretical predictions have been experimentally confirmed Moldarev et al, 2018 [5]. The electronic properties and chemical bonding of YH 3−2x O x have been studied [3,19], but work on other REMOHs has not been systematic.…”

“…The first systematic studies of REMOHs using first-principle calculations have been performed [16][17][18][19]. Understanding film composition and establishing YHO's chemical formula were crucial steps.…”

Analysis of TihxOy Films Produced by Physical Vapor Deposition Method

“…In partially oxidized yttrium hydride and several other rare-earth (Gd, Dy, and Er) hydrides, reversible switching of optical transmittance under intense irradiation was observed [13]. This feature of yttrium oxyhydride is currently being tested for application in smart window devices [14].…”

Modification of the Photochromic Properties of Oxygen-Containing Yttrium Hydride by Irradiation with keV and MeV Ions

“…The effect persists when the films are coated with a protective layer (Al 2 O 3 or Si 3 N 4 ) 6 enabling their utilization in multilayered structures. 7 Thin films of YHO are typically produced by either reactive magnetron sputtering 3 or e − beam evaporation 8 of yttrium dihydride followed by oxidation and they show photochromic properties in a range of chemical compositions with the oxygen to yttrium ratio δ of 0.5 < δ < 1.5. 9 Moreover, photochromism is commonly coupled to photoconductivity, 3,10 even though the latter one is also found in YHO films with δ < 0.5.…”

“…Photochromic materials feature a change in optical properties as a response to electromagnetic irradiation, which makes them enticing for a vast number of applications in different fields like smart windows, sensors, and ophthalmology. , Oxygen-containing yttrium hydride (YHO) along with some other oxygen-containing rare-earth metal hydrides (ScHO, NdHO, GdHO, DyHO, and ErHO) , were shown to feature a color-neutral photochromic effect at ambient conditions. The effect persists when the films are coated with a protective layer (Al 2 O 3 or Si 3 N 4 ) enabling their utilization in multilayered structures . Thin films of YHO are typically produced by either reactive magnetron sputtering or e – beam evaporation of yttrium dihydride followed by oxidation and they show photochromic properties in a range of chemical compositions with the oxygen to yttrium ratio δ of 0.5 < δ < 1.5 .…”