New shades of photochromism - yellow sodalites for the detection of blue light



: Byron Hannah, Kreivilä Teppo, Colinet Pauline, Le Bahers Tangui, Lastusaari Mika

Publisher: ROYAL SOC CHEMISTRY

: 2023

: Journal of Materials Chemistry. C

: JOURNAL OF MATERIALS CHEMISTRY C

: J MATER CHEM C

: 11

: 9

: 3360

: 3374

: 15

: 2050-7526

: 2050-7534

DOI: https://doi.org/10.1039/d3tc00116d

: https://doi.org/10.1039/D3TC00116D

: https://research.utu.fi/converis/portal/detail/Publication/178946996


The absorption energy of the F-center in photochromic sodalite can be lowered by expanding the unit cell with larger ions, changing the color from pink to blue. Blue-shifting this absorption to produce other colors is not so straightforward. In this work, sodalites of the formula Na2-2xCax(Na,K)(6)(AlSiO4)(6)(Cl,S)(2) displaying white-to-yellow photochromism have been prepared and thoroughly characterized. Combining spectroscopic experiments and quantum chemical calculations, the formation of a Na2Ca entity inside the sodalite cage surrounding the trapped electron responsible for the yellow color is postulated. Optimal yellow photochromism occurs for 0.13 <= x <= 0.18, while at x >= 0.27 the formation of the by-product davyne begins to affect the structure and optical properties. Finally, the sensitivity of these materials to blue light is shown to make them well-suited as sensors for blue light over-exposure e.g. from computer screens or smart phones.

Last updated on 2024-26-11 at 16:17