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Structural color filters have recently blossomed as a superior alternative to organic dyes or chemical pigments owing to their remarkable durability and compactness. With appropriate design, nanostructure‐induced photonic or plasmonic resonance modes can give rise to either enhancement in transmission or suppression in the reflection within specific wavelength ranges in the optical regime, generating distinctive colors. However, the static optical properties due to fixed structural geometry and size after fabrication hinder their deployment in many cutting‐edge technologies requiring adaptive complexion changes. Here, a multilayer thin film‐based color filter incorporating Mg and MgO, earth‐abundant and biodegradable materials, is devised. The devices display vivid hues spanning a broad gamut via the control of the film thickness. They also exhibit minimal color changes with varying angle views up to 40°–50°. Moreover, the tones fade away instantly upon immersion in water and then progressively transition to a different hue with the complete removal of the Mg‐containing layers, realizing transient color responses. This approach holds great promise for alternative pixels with irreversible color‐change capability as well as zero‐power consumption and low cost, while making use of biodegradable materials. [ABSTRACT FROM AUTHOR]

Metal halide perovskites (MHP) can be made more stable through the addition of small amounts of cesium. Despite the improvement, these multication absorbers still display strong environmental sensitivity to any combination of factors, including water, oxygen, bias, temperature, and light. Here, the relationship is elucidated between light absorption, charge carrier radiative recombination, and relative humidity (rH) for the Cs0.05FA0.79MA0.16Pb(I0.83Br0.17)3 composition, revealing partially reversible reductions in the extinction coefficient and fully reversible 25× enhancements in absolute light emission registered across the same humidity cycles up to 70% rH. With in situ excitation wavelength‐dependent measurements, irreversible changes are identified in the perovskite after a single cycle of humidity‐dependent photoluminescence (PL) performed with 450 nm excitation. The in situ measurement platform can be extended to test the effect of other stressors on thin films' optical behavior. [ABSTRACT FROM AUTHOR]

Keywords: color filters; earth-abundant materials; magnesium; structural colors; transient photonics EN color filters earth-abundant materials magnesium structural colors transient photonics 1 1 1 07/06/22 20220704 NES 220704 Marina S. Leite and co-workers (article number 2200159) demonstrate thin-film-based color filters using Mg and MgO, both biodegradable materials. Color filters, earth-abundant materials, magnesium, structural colors, transient photonics A transient color response is attained by etching the Mg-containing layers with water, which reveals the hue of a bottom Fabry-Pérot cavity structure. [Extracted from the article]

Light absorption, metal halide perovskites, photoluminescence, environmentally-dependent measurements Keywords: environmentally-dependent measurements; light absorption; metal halide perovskites; photoluminescence EN environmentally-dependent measurements light absorption metal halide perovskites photoluminescence 1 1 1 09/22/21 20210920 NES 210920 Marina S. Leite and co-workers (article number 2100710) unveil the relationship between light absorption, charge carrier radiative recombination, and relative humidity (rH) for the Cs SB 0.05 sb FA SB 0.79 sb MA SB 0.16 sb Pb(I SB 0.83 sb Br SB 0.17 sb ) SB 3 sb halide perovskite. Water-Induced and Wavelength-Dependent Light Absorption and Emission Dynamics in Triple-Cation Halide Perovskites (Advanced Optical Materials 18/2021). [Extracted from the article]