ABSTRACT Radiative cooling is an emerging thermal management technology that cools objects by reflecting solar radiation and emitting heat through the atmospheric transparency window (ATW). Recent studies in radiative cooling have emphasized coating‐ or paint‐based designs for practicality. However, most existing coatings are restricted to white or metallic colors, limiting their use where vivid colors are desired. Colored radiative cooling (CRC) coating is therefore highly valuable, yet many reported designs rely on complex multilayer structures or suffer from performance loss upon coloration. In this study, a single‐layer colored radiative cooling (SCRC) paint that achieves intense coloration and high cooling efficiency is reported. SCRC paints incorporate wide‐bandgap hexagonal boron nitride (h‐BN) particles and hybrid chromatic pigments dispersed in polyurethane (PU) binder. Red, yellow, blue, and white SCRC paints are realized, achieving near‐infrared (NIR) reflectance of 97% for red, yellow, and white, and 90% for blue, despite deep coloration. Significant cooling was observed compared to commercial paints of similar colors, with temperature reductions exceeding 6°C for red, yellow, and white, and 4°C for blue. These findings demonstrate that SCRC paints uniquely integrate vivid coloration, structural simplicity, and robust cooling performance, offering a practical route for real‐world applications.

ABSTRACT The lead halide perovskite single crystals (SCs) have already emerged as a series of star materials for solar cells, lasers and detectors due to the complete crystal structure, fewer defects and grain boundaries. Previous studies have demonstrated that MASCN gas can convert δ‐FAPbI 3 films into α‐FAPbI 3 below the phase transition temperature. However, applying this strategy to the exploration of FAPbI 3 SCs remains a challenge. Herein, we designed a constant‐pressure gas diffusion setup to treat δ‐FAPbI 3 SCs with MASCN vapor, successfully obtaining photoactive α‐FAPbI 3 SCs with enhanced optoelectronic properties. X‐ray detectors based on the processed SCs exhibited significantly improved performance, achieving a high sensitivity of 4.46 × 10 4 µC Gy air −1 cm −2 , a ratio of sensitivity to dark current density as high as 1.06 × 10 12 µs Gy air −1 , and a detection limit as low as 150 nGy air s −1 . Furthermore, due to the strong polarizing nature of sulfur, some SCN − ions formed stable bonds with Pb 2+ in the crystal lattice, thereby enhancing the environmental stability of FAPbI 3 . The processed SCs maintained their phase purity without degradation after one month of storage in ambient conditions. This work offers a new strategy for repurposing δ‐FAPbI 3 SCs and advances the development of perovskite SC X‐ray detectors.

Abstract Bismuth‐based organic–inorganic hybrid semiconductors have practical limitations in optoelectronic applications due to low carrier separation and collection efficiency. This study proposes an intramolecular carrier transfer strategy to enhance carrier separation by forming a type‐II heterojunction between the organic and inorganic components. Extended methyl viologens (eMVs) are used as the A‐site. Theoretical calculations and transient absorption analyses confirm electron transfer from the inorganic to the organic part. The organic cation acts as an electron reservoir, suppressing the recombination of photogenerated carriers and promoting separation and stabilization. In particular, modulating the heteroaromatic system improves the storage capacity of the electron reservoir and enhances its role in stabilizing carriers. Me 2 Py 2 TTzBi 2 I 8 exhibits excellent photoelectric responses, with an on/off ratio of 120 and high X‐ray sensitivity of up to 259 µC Gy air −1 cm −2 , with a low detection limit of 320 nGy air s −1 , indicating its potential application in detectors. Additionally, the π ‐conjugated cations protect the Bi─I octahedral chain from decomposition, enabling it to withstand harsh conditions such as water, acidity, and high/low temperatures. This work provides new ideas for designing organic cations in bismuth‐based hybrid semiconductors, which are expected to overcome the limitations of carrier collection and develop new, high‐performance materials.

Reconfigurable Metasurface An input pulse with a time-modulated envelope (top) passes through a cascaded bilayer metasurface device, which imparts a mixed-order time-derivative operation on the pulse envelope function (bottom). By exploiting the twist degrees of freedom between the two layers, the mathematical operation imparted from the device can be continuously tuned between zeroth, first, and second time-differentiation. More details can be found in the Research Article by Felix Wong and Michele Cotrufo (DOI: 10.1002/adom.202502326).

ABSTRACT Sensitized triplet‐triplet annihilation upconversion (sTTA‐UC) is an emerging strategy for driving photoredox catalysis using low‐energy red or near‐infrared (NIR) light. However, its application in aqueous environment is often hindered by the poor solubility of requisite chromophores. Here, we address this challenge with water‐stable sTTA‐UC nanoparticles that encapsulate a hydrophobic red‐to‐blue upconversion pair within 100 nm‐sized polystyrene (PS) nanoparticles. These nanoparticles exhibit high colloidal stability in water without chromophore leakage and sufficient photostability for photocatalysis. They serve as highly active heterogeneous photoredox catalysts, successfully mediating the aqueous polymerization of various acrylate monomers under red light irradiation to form free‐standing polymer gels with high conversion yields. This work establishes our photorobust and water‐stable sTTA‐UC nanoparticles as effective heterogeneous photocatalysts for polymer synthesis with red light, offering a versatile and attractive platform for chemical transformations in aqueous environment.

ABSTRACT Conventional electromagnetic interference (EMI) shielding films rely on high loadings of conductive materials to achieve strong shielding effectiveness, but this approach inevitably reduces optical transmittance, increases haze, and compromises visual fidelity. Here, we report an optically transparent EMI shielding metamaterial, configured as an array of double‐shell hexagonal resonators with symmetric capacitive gaps. The metamaterial, implemented as a single thin Cu layer (300 nm) on bare glass, featured a 0.7% metal filling fraction yet attained an average visible transmittance of 91.2%, practically indistinguishable from that of uncoated glass. Despite this ultralow metal content, the metamaterial‐coated glass exhibited moderate EMI shielding, with reflection (∣S 11 ∣ 2 ) and transmission (∣S 21 ∣ 2 ) levels of −2.1 and −16.1 dB, respectively, at the target microwave frequency of 14.9 GHz. This shielding performance originated from an epsilon‐mu‐near‐zero resonance, as confirmed by extracted permittivity and permeability dispersions. Practical validation is demonstrated by integrating the metamaterial into a commercial radar system, where it completely blocked microwave signal detection. We believe that optically transparent EMI shielding will become crucial for emerging technologies that require visual access through the shielding layer, such as semiconductor inspection platforms and transparent displays.

Zero-Order Waveplate Waveplates have attracted increasing attention due to their irreplaceable role in polarization optics. For a long time, zero-order waveplates exhibited ultra-thin machining and application difficulties because the birefringence of the crystal was not small enough. Through non-principal axis cutting, even materials with large birefringence can achieve appropriate birefringence values by adjusting the incident direction, thereby expanding the selection range of waveplate materials and achieving precise phase control of light waves in a wide spectral range, breaking the limitations of the inherent birefringence and transmittance band of a single material. More details can be found in the Research Article by Lijuan Chen, Zeliang Gao, and co-workers (DOI: 10.1002/adom.202502910).

ABSTRACT The pressure‐induced blue‐white emission of materials provided possibility of single‐component white light‐emitting diodes (WLEDs). However, the high‐pressure metastable phase with excellent blue‐white emission is very difficult to be stabilized at ambient conditions, seriously limiting the practical applications. Here, we successfully quenched a blue‐white emission in a 0D perovskite (C 9 H 9 N 5 ) 2 ZnCl 4 ·2H 2 O upon decompression, which exhibited a stark increase by a factor of more than 40 and CIE coordinates of (0.248, 0.308). Strengthening of intermolecular hydrogen bonds, increased tetrahedra distortion, and inhibit of the phonon‐assisted non‐radiative decay are highly responsible for the observed emission enhancement. The retention mechanism of enhanced blue‐white emission is associated with large steric hindrance effect of complex organic cation, which contributed to increasing the potential barrier of phase transition. Furthermore, the phosphor‐converted light emitting diode (pc‐LED) is fabricated using pressure‐treated (C 9 H 9 N 5 ) 2 ZnCl 4 ·2H 2 O, which exhibited superior chromaticity. Combined with micro‐nano patterning, diverse patterns of QR codes and butterflies are achieved. The QR codes after pressure treatment can be easily scanned for accessing the homepage of Jilin University with a phone, which considerably enhanced the ability of naked‐eye recognition and visual information encryption. Pressure indeed offers a robust strategy to endow high‐efficiency luminescent materials with great potentials in lighting, display and anti‐counterfeiting.

ABSTRACT Resonances with simultaneous high quality factor (Q‐factor) and sensitivity are essential for accurate detection of environmental changes and molecular interactions. However, current sensing designs often face a trade‐off between these two metrics. Here, we overcome this trade‐off by harnessing quasi‐bound states in the continuum (QBICs) on the Bloch surface wave (BSW) platform. We introduce a perturbation layer that induces the transition from a BSW‐based resonance to a QBIC. This design enables the simultaneous optimization of both Q‐factor and sensitivity without trade‐offs. The Q‐factor is primarily optimized through structural symmetry, whereas sensitivity is determined by structural parameters associated with the BSW properties. The optimal design achieves a simulated bulk refractive index sensitivity of 1155 nm/RIU and a corresponding figure of merit exceeding 10 5 . We experimentally demonstrate the QBIC with a Q‐factor of 11 000 and surface sensitivity comparable to that of plasmonic resonances, reaching a 9.85 nm resonance shift upon deposition of a 10‐nm‐thick SiO 2 layer. Further validation through immunoglobulin G (IgG) sensing reveals clear resonance shifts following each surface functionalization step, with no overlap with the original resonance peak. These results establish the design of QBIC on the BSW platform as a promising approach for high‐resolution, label‐free integrated photonic sensing systems.

ABSTRACT The unique combination of strong excitonic properties and environmental stability in 0D copper halide crystals motivates the development of scalable ambient fabrication routes for high‐quality emitters. Here, we report a low‐temperature solvent vapor‐assisted crystallization strategy to grow millimeter‐sized Cs 3 Cu 2 I 5 crystals. Rb + doping effectively passivates surface defects, markedly enhancing moisture and ambient stability, with the photoluminescence intensity remaining nearly unchanged after 60 days in air. Notably, the 10% Rb + ‐doped crystals achieve a high photoluminescence quantum yield (PLQY) of 98.42%, demonstrating a pronounced emission enhancement. Ab initio molecular dynamics (AIMD) simulations reveal that both pristine and 10% Rb + ‐doped structures reside in a similar energy window (−108 to −110 eV), while the doped system exhibits a more confined trajectory, suggesting a flattened energy landscape and suppressed defect formation. Doped lattice relaxations induce slight, direction‐dependent bond contraction, improving coordination integrity without major distortion, consistent with material stability and device reliability. By integrating blue‐emitting Cs 3 Cu 2 I 5 :10% Rb + with green Cs 3 Cu 2 Cl 5 and red CaAlSiN 3 :Eu 2+ , we fabricate high‐performance white light‐emitting diodes (WLEDs) achieving CRI of 95.36, CIE chromaticity coordinates of (0.30, 0.34), and outstanding luminance of 17734.5 cd/m 2 . These findings establish a versatile ambient pathway for defect‐engineered Cs 3 Cu 2 X 5 (X = I, Cl) emitters, advancing their prospects for next‐generation solid‐state lighting technologies.