We report heterointerfacial construction in the cocrystallization structures of a green-emitting perovskite and a red-emitting small-molecular semiconductor, where blend nanocrystal clusters were produced between CH3NH3PbBr3 (MAPbBr(3)) and N, N'-bis(1-ethylpropyl)-3,4,9,10-perylenetetracarboxdiimide (EPPTC) using solution processible method. The blend film was prepared by dropping the EPPTC/chloroform solution onto the spin-coating CH3NH3PbBr3/DMF solution at a delay of 8 s. The concentrations of both solutions have also been optimized, so that a crystallization pattern was achieved with EPPTC stacked in the center and MAPbBr(3) extends on the outer ring. The formation of heterojunctions is evidenced not only by the microscopic characterization, but also by new features in the photoluminescence spectrum. The mechanisms for electronic transitions on the heterointerfaces were resolved and more clearly verified by the decay dynamics of the emission within a largely redshifted band.

Hybrid organic inorganic perovskites exhibit multifold advantages in their charge-transport performance and applications in optoelectronic devices. Mixtures of them during the synthesis process enable largely enhanced tunability in both the optical spectroscopic response of the materials and structural design of the light-emitting or photodetection devices. However, phase separation is usually observed in the mixture materials CH3NH3PbBrXI3-X (MAPbBrXI3-X) under optical excitation, which is based on the induced aggregation of iodine ions (I-) to the positively charged MA+, leading to a much modulated photoluminescence (PL) spectrum by a new feature at longer wavelengths. The available reports still lack insights into the dynamics of the responsible mechanisms. In this work, we employ CH3NH3PbBr1.5I1.5 as a typical example and 80 ps laser pulses at about 405 nm with varied repetition rate as the excitation. In addition to the intrinsic emission of MAPbBr1.5I1.5 at about 658 nm, a new spectral feature centered at about 734 nm is identified as the emission from the new phase with I--enrichment. Focusing on the emission spectrum around 734 nm, we were able to investigate how the phase-separation effect depends on the repetition rate, pulse energy, average power, and interaction time duration. Thus, these transient spectroscopic indications facilitate comprehensive understanding of the phase-separation mechanisms and determine the typical spectroscopic features accordingly in MAPbBrXI3-X.

Achieving quantitative and reproducible surface-enhanced Raman scattering (SERS) detection remains challenging due to the stochastic nature of molecular distribution and the nonuniform enhancement of localized plasmonic "hot spots". Here, we present a wettability-patterned Ag nanoparticles and ZnO nanorod (Ag/ZnO)-nanostructured substrate that enables self-metered droplet partitioning and uniform molecular deposition for quantitative SERS sensing. By exploiting the strong contrast between hydrophilic and hydrophobic regions, a bulk liquid droplet can spontaneously split into an array of equal-volume microdroplets without any external confinement. During evaporation, the hydrophilic Ag/ZnO nanocolumns induce capillary-driven infiltration, which, in combination with wettability confinement, effectively suppresses the coffee ring effect and ensures homogeneous solute deposition within a defined area. Systematic comparisons among hydrophilic, flat-patterned, and nanostructured-patterned substrates reveal distinct drying dynamics, confirming that the synergistic control of capillary infiltration and wettability patterning governs uniform analyte distribution. Consequently, the designed substrate delivers highly linear and reproducible (RSD < 5%) SERS responses across multiple domains and analyte types. This simple yet robust self-metered droplet strategy provides a practical route toward uniform, quantitative, and molecule-independent SERS detection, offering new opportunities for reliable chemical and biosensing applications.

Although extensive past efforts were devoted to designing substrates exhibiting abundant hotspots for improving the detection sensitivity of surface-enhanced Raman spectroscopy (SERS), how to transport analyte molecules under detection to those hotspots remains challenging. Here, we propose a meta-grating-based SERS sensor with periodically arranged nanogaps exhibiting gradient shapes that can efficiently transport molecules to the hotspots with significantly intensified electromagnetic fields, thus pronouncedly enhancing the sensitivity and signal uniformity of the SERS detection. We fabricate the proposed SERS substrate and demonstrate the desired SERS-detection improvement with experimental measurements on rhodamine 6 G (R6G, 10(-6)-10(-11) M), crystal violet (CV, 10(-8)-10(-13) M), and glycine molecules (40-0.1 mM) with different concentrations. Our measured two-dimensional mappings of SERS intensity exhibit good signal uniformity, with calculated relative intensity deviation less than 10%, obtained by analyzing 100 randomly selected points, either for R6G, CV, or for glycine. Our results lay a solid foundation for quantitative molecule detection based on SERS technology.

Continuously wavelength-tunable perovskite lasers have emerged as compelling candidates for integrated optoelectronic devices, particularly in optical research and communication applications. Nevertheless, current configuration designs of perovskite tunable lasers typically rely on multiple spatially separated perovskite materials within a single laser architecture, which significantly impedes the integration of optoelectronic devices. In this work, we present an innovative design featuring an intracavity liquid crystal (LC)-integrated continuously wavelength-tunable single-mode perovskite vertical-cavity surface-emitting laser (VCSEL). This flexible wavelength tunability function of the developed perovskite laser is realized through the voltage-driven variations in the refractive index of the liquid crystal layer and effective cavity length, thereby enabling dynamic manipulation of emission spectral. Consequently, a continuous spectral tuning range from 811 nm to 783 nm was achieved with the increasing applied voltage, accompanied by a decent threshold of 2.35 mu J cm-2 and a superior operational stability. Synchronously, a thermally induced wavelength shift from 811 nm to 792 nm was also observed as the temperature rose from 25 degrees C to 40 degrees C, underscoring an exceptional thermal tuning capability. The integration of liquid crystals with perovskite laser holds substantial promise for the advancement of optoelectronic devices, providing novel insights for the future progression of perovskite laser technology.

The recent emergence of organic-inorganic hybrid metal halides (MHs) with room-temperature phosphorescence (RTP) has attracted tremendous attention due to their promising properties. Great progress has been made in developing MH materials with high-performance RTP, but a systematic study on MH materials with RTP feature is lacking. This review highlights recent advances in MH RTP materials, including lead-based hybrid metal halides, lead-free hybrid metal halides and ion-doped hybrid metal halides. Additionally, the photophysical properties and the applications of MH RTP materials are discussed in detail. These RTP materials have been successfully applied in data encryption and security, intelligent sensing and optoelectronic devices. This review not only provides the basic principles for designing RTP hybrid metal halides, but also highlights the future research prospects of RTP hybrid metal halides. This review offers many effective strategies for developing hybrid metal halides with excellent RTP properties, thus satisfying practical applications.

Rapid, ultrasensitive, and specific detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains challenging, particularly for micro-volume samples. This study presents a capillary-based threedimensional Ag/ZnO nanorod surface-enhanced Raman spectroscopy (SERS) biosensing platform that enables dual-mode (liquid and aerosol) viral detection within the same device. The capillary configuration inherently provides a large surface-to-volume ratio and acts as a confined reaction chamber, eliminating the need for external liquid or gas cells while minimizing sample consumption. Vertically aligned Ag/ZnO nanorod arrays grown on the inner wall further increase the density of electromagnetic hotspots, achieving an enhancement factor of 1.07 & times; 10 1 1 with excellent signal uniformity (RSD = 4.65%). After ACE2 functionalization, the biosensor enables label-free, direct detection of the 2019-nCoV antigen S protein in phosphate-buffered saline (PBS) and pharyngeal swabs solution (PSS), with a limit of detection (LOD) of 1 fg/mL. In addition, a sandwich-structured sensing configuration was designed to further amplify the Raman response. Importantly, without additional instrumentation, the same capillary SERS platform also enables direct detection of the 2019-nCoV antigen S protein aerosol with a LOD of 10 fg/mL and the SARS-CoV-2 Spike Pseudovirus at 100 fg/mL. This biosensor integrates sampling, enrichment, and readout in a low-volume device, reduces the risk of cross-contamination, and maintains high analytical performance.

ABSTRACT Radiation detection has been developed as a powerful imaging technology with wide applications in medical diagnostics, non‐destructive testing, and astronomy. Metal halide hybrids have emerged as promising scintillators owing to their facile synthesis, rich structural diversity, and superior scintillation performance, which effectively address the limitations of conventional inorganic scintillators including complex fabrication, radioluminescence afterglow, and mechanical rigidity. Notably, copper(I) iodide hybrids, benefiting from unique coordination modes, tunable radioluminescence property, good stability, and processability, have achieved rapid progress, demonstrating significant potential for high‐performance scintillators. In this review, we summarize the recent advances in hybrid copper iodide scintillators from the perspective of molecular architecture and scintillation properties. The scintillation mechanism and key parameters for scintillators are first elucidated to highlight the essential prerequisites for high‐performance scintillators. Subsequently, copper iodide hybrids are categorized according to their connection modes and inorganic motifs, with a detailed discussion of their characteristics and recent advances. Particular attention is devoted to emphasizing the synthetic procedure, luminescence mechanism, and scintillation properties of the scintillators featuring different structural types, aiming to inspire the identification of structures with promising scintillation properties. Finally, we highlight prevailing challenges and propose future opportunities for the advancement of high‐performance scintillators tailored to specific applications.

Holographic polymer-dispersed liquid crystal (HPDLC) gratings have great potential for applications in displays and data storage due to their exceptional optical modulation capabilities. Since their optical performance strongly depends on the phase separation between the polymer and liquid crystal (LC) induced by the photopolymerization, it is essential for improving the performance of HPDLC through the photokinetic aspect. In this work, we report (for the first time, to our knowledge) an enhanced HPDLC grating by using the reversible addition-fracture chain transfer (RAFT) agent. Experimental results show that a p-polarization diffraction efficiency (η) of 84% and a refractive index modulation (Δn) as high as 0.07 with the addition of RAFT are achieved in a 3-μm HPDLC grating. Significantly, comparing with the undoped grating, this corresponds to a near two-fold enhancement on η and an improvement of 62% on Δn. Moreover, we confirm that an increase in the size of LC-rich phase leads to a decreasing in the threshold voltage. We believe that the enhancement of HPDLC performance by RAFT provides an effective path to optimize the holographic photopolymer materials for uses of AR display and holographic data storage.

ABSTRACT Laser phosphor display is promising for next‐generation high‐quality display technology due to its high brightness, wide color gamut, and low speckle. However, the lack of high performance narrow‐band green emitters with robust laser resistance remains a critical bottleneck. Herein, we develop RbSr 4 (BO 3 ) 3 :Eu 2+ (RSBO:Eu 2+ ) as a narrow‐band green emitter, which exhibits an emission peak at 526 nm with a narrow full width at half maximum of only 50 nm under blue light excitation. The highly dense and rigid host framework effectively suppresses lattice relaxation and electron–phonon coupling despite Eu 2+ occupying multiple cation sites in RSBO. Highly stable RSBO:Eu 2+ was further embedded into a low‐melting P 2 O 5 ‐Al 2 O 3 ‐B 2 O 3 ‐Na 2 O glass matrix to fabricate a phosphor‐glass composite (RSBO:Eu‐PGC), demonstrating good thermal stability and a high saturation threshold exceeding 40 W/mm 2 . The corresponding rotating phosphor wheel maintained a low surface temperature of 79.9°C under 40 W/mm 2 blue‐laser irradiation, effectively mitigating thermal degradation. A prototype laser display system using a rotating wheel integrating RSBO:Eu‐PGC and K 2 SiF 6 :Mn 4+ ‐PGC achieved a wide color gamut of 107% National Television System Committee (NTSC) standard, which highlights the great potential of narrow‐band green‐emitting RSBO:Eu‐PGC for laser phosphor display applications.

Free-exciton (FE) emission is rarely achieved in zero-dimensional (0D) tin halides, where strong electron-phonon coupling induces exciton self-trapping, producing broadband self-trapped exciton (STE) emission and limiting narrow FE blue emission....

Abstract Metal halide perovskite light-emitting diodes offer a promising platform for low-cost full-color displays, yet achieving high-performance pure-red emission remains challenging. Here, we report a crystallization regulation strategy for mixed bromide/iodide quasi-two-dimensional perovskites using a multifunctional molecule, 4-(trifluoromethyl)benzenesulfonamide, which simultaneously coordinates with organic spacer cations, Pb 2+ ions and halide ions. Moreover, the combination of large steric hindrance and ordered molecular assembly in the precursor solution plays a decisive role in directing the formation of nanocrystals, thereby suppressing defect formation, inhibiting halide ions migration, and enhancing exciton binding energy. The resulting light-emitting diodes exhibited pure-red emission at ~635 nm, delivering a peak external quantum efficiency of 30.2%, a maximum luminance exceeding 25,000 cd m -2 , and a half-lifetime of 8426 min. Achieving perovskite light-emitting diodes with performance comparable to that of quantum-dot or organic light-emitting diodes would mark a major milestone toward commercialization. This work would expand opportunities beyond conventional light-emitting diode technologies.

Eu2+-activated inorganic phosphors are widely used in optoelectronic fields due to their superior luminescence properties. However, stabilizing Eu2+ dopants at trivalent Ln3+ sites in Ln(III)-based phosphors (Ln = Y3+, La3+, and Lu3+) remains challenging because of charge imbalance and lattice instability, which has limited related luminescence mechanistic insights and materials discovery. Here, we propose a universal strategy that introduces interstitial alkali-metal defects to break through the thermodynamic and kinetic constraints of Eu3+-> Eu2+ reduction in Ln(III)-based hosts. High-throughput experiments validate the effectiveness of this approach across multiple host systems. As a proof of concept in classical Lu2SiO5, the introduced interstitial Na drives the emission from a sharp red Eu3+ line to a broad green Eu2+ band at similar to 500 nm with persistent luminescence exceeding 10 h. The interstitial Na defects act dually by promoting Eu3+-> Eu2+ reduction and serving as an afterglow energy reservoir. The remarkable afterglow property enables multifunctional applications in advanced information encryption and fingerprint recognition. This work demonstrates a promising approach to exploring Eu2+ luminescence properties in established materials via defect-assisted reductive engineering, opening avenues for developing new optofunctional materials.

Surface-enhanced Raman scattering (SERS) sensors offer high-sensitivity, high-specificity, and high-speed detection of low-concentration molecules with low costs. High stability of the device is a key issue in the design and application of this category of sensors. However, SERS detection with strong and high-contrast Raman signals requires strong laser excitation of the target molecules, which may lead to the damage of the metallic nanostructures on the SERS substrates by photothermal effects, reducing largely the reliability of the detection data. In this study, we present a SERS substrate fabricated by depositing silver nanoparticles (AgNPs) onto the polytetrafluoroethylene (PTFE)-modified carbon paper (CP), which is defined as the CP-PTFE-AgNP sensor. The fabrication parameters were systematically adjusted to optimize the SERS-active nanostructures with significantly improved sensing performance. The fabricated sensor exhibits exceptional photostability, maintaining optimal performance even under high excitation laser intensity. Using R6G as a probe molecule, it demonstrates an ultrahigh enhancement factor of 2.66 x 1012 and a remarkably low detection limit of 10-17 M. Furthermore, the high-sensitivity detection of ciprofloxacin in water and bilirubin in serum implies promising applications of such a design of SERS devices. These experimental results indicate that this highly stable SERS sensor holds great potential for point-of-care testing applications in fields such as environmental monitoring and biomedical diagnostics.

Laser phosphor display is promising for next-generation high-quality display technology due to its high brightness, wide color gamut, and low speckle. However, the lack of high performance narrow-band green emitters with robust laser resistance remains a critical bottleneck. Herein, we develop RbSr4(BO3)3:Eu2+ (RSBO:Eu2+) as a narrow-band green emitter, which exhibits an emission peak at 526 nm with a narrow full width at half maximum of only 50 nm under blue light excitation. The highly dense and rigid host framework effectively suppresses lattice relaxation and electron-phonon coupling despite Eu2+ occupying multiple cation sites in RSBO. Highly stable RSBO:Eu2+ was further embedded into a low-melting P2O5-Al2O3-B2O3-Na2O glass matrix to fabricate a phosphor-glass composite (RSBO:Eu-PGC), demonstrating good thermal stability and a high saturation threshold exceeding 40 W/mm2. The corresponding rotating phosphor wheel maintained a low surface temperature of 79.9 degrees C under 40 W/mm2 blue-laser irradiation, effectively mitigating thermal degradation. A prototype laser display system using a rotating wheel integrating RSBO:Eu-PGC and K2SiF6:Mn4+-PGC achieved a wide color gamut of 107% National Television System Committee (NTSC) standard, which highlights the great potential of narrow-band green-emitting RSBO:Eu-PGC for laser phosphor display applications.

Perovskite quantum dots (PQDs) are promising gain media for low-threshold lasers, yet their integration into high-quality distributed feedback (DFB) cavities has been severely limited by poor film compactness and morphological inhomogeneity. Here, we report a high-performance CsPbBr3 QD DFB laser enabled by a high-concentration mixed-solvent film-formation strategy. Strongly binding 4-dodecylbenzenesulfonic acid ligands allow the preparation of colloidally stable CsPbBr3 QD inks with concentrations up to 200 mg mL-1, providing sufficient optical gain. By introducing a binary solvent system composed of n-hexane and n-octane, the evaporation kinetics and fluid dynamics during spin coating are effectively regulated, yielding dense yet ultra-smooth QD films. The optimized films exhibit strong waveguide-grating coupling, manifested by pronounced extinction resonances and a markedly enhanced Purcell effect upon integration with DFB gratings. As a result, efficient distributed feedback oscillation is achieved, leading to stable single-mode surface-emitting lasing with a linewidth as narrow as 0.23 nm, a low threshold of 29 & micro;J cm-2, and a quality factor of approximately 2300. This work provides a versatile solution to overcome film-quality-induced cavity losses in CsPbBr3 QD DFB lasers, and is expected to promote the development of high-Q-factor QD microcavity lasers.