Quantum Yield Research Articles

Loading Dyes into Chiral Cd/Zn‐Metal–Organic Frameworks for Efficient Full‐Color Circularly Polarized Luminescence

AbstractHost‐guest chemistry of chiral metal‐organic frameworks (MOFs) has endowed them with circularly polarized luminescence (CPL), it is still limited for MOFs to systematically tune full‐color CPL emissions and sizes. This work directionally assembles the chiral ligands, metal sites and organic dyes to prepare a series of crystalline enantiomeric D/L‐Cd/Zn‐n MOFs (n=1~5, representing the adding amount of dyes), where D/L‐Cd/Zn with the formula of Cd2(D/L–Cam)2(TPyPE) and Zn2(D/L–Cam)2(TPyPE) (D/L‐Cam=D/L‐camphoric acid, TPyPE=4,4’,4’’,4’’’‐(1,2‐henediidenetetra‐4,1‐phenylene)tetrakis[pyridine]) were used as the chiral platforms. The framework‐dye‐enabled emission and through‐space chirality transfer facilitate D/L‐Cd/Zn‐n bright full‐color CPL activity. The ideal yellow CPL of D‐Cd‐5 and D‐Zn‐4, with |glum| as 4.9 × 10−3 and 1.3×10−3 and relatively high photoluminescence quantum yield of 40.79 % and 45.40 %, are further assembled into a white CPL light‐emitting diode. The crystal sizes of D/L‐Cd/Zn‐n were found to be strongly correlated to the types and additional amounts of organic dyes, that the positive organic dyes allow for the preparation of > 7 mm bulks and negative dyes account for sub‐20 μm particles. This work opens a new avenue to fabricate full‐color emissive CPL composites and provides a potentially universal method for controlling the size of optical platforms.

Managing Edge States in Reduced-Dimensional Perovskites for Highly Efficient Deep-Blue LEDs.

Pure-halide reduced-dimensional perovskites, featuring large exciton binding energy and tunable bandgap, show great potential for high-efficiency deep-blue perovskite light-emitting diodes (PeLEDs). However, their efficiency, particularly in the low n-value phase domain ("n" represents the number of octahedral sheets), lags behind analogous perovskite emitters. Herein, it is demonstrated that the vibration of edge-dangling octahedra in the low n-value phase activates notorious exciton-phonon (EP) coupling, thereby deteriorating efficiency. To address this issue, an approach is reported to manage edge-state lattices by introducing tris(4-fluorophenyl) phosphine (TFP) ligands. Attributed to the large steric hindrance of TFP ligands and their strong binding affinity for edge-dangling octahedra, the edged-octahedral tilting reconstruction can effectively suppress lattice vibration and inhibit EP coupling. This strategy yields deep-blue emitting film with a spectral linewidth of 21nm and a photoluminescence quantum yield of 85% at low excitation densities. The resulting PeLEDs achieve deep-blue emission at 469nm, with a maximum luminance of 2,428cdm-2 and a maximum external quantum efficiency of 10.4%, marking them among the most efficient deep-blue PeLEDs reported. The strategy also showcases universality for higher n-value reduced-dimensional perovskites. It is believed that the observation, along with the edge-state management strategy, lays the groundwork for further advancements in reduced-dimensional perovskite optoelectronic devices.

High-efficiency pure-red perovskite quantum dots glass via Dy modification for high quality backlight display

Perovskite quantum dots (QDs) glass has been considered as high efficiency, high color-purity, and high stability luminescent materials for display application. Herein, high emissive Dy doped CsPb(Br, I)3 (CPBI: Dy) QDs glass has been prepared, and the effects of doping concentration on the crystallization behavior of QDs were discussed carefully. The low and high concentration of Dy doping brings diametrically opposite tuning effects for the emission wavelength. When high Dy doping, DyBO3 nanocrystals were precipitated from the glass along with CPBI QDs. The highest photoluminescence quantum yield of CPBI: Dy QDs glass reached 53.79 %. The LEDs using the CPBI: Dy QDs glass as color converter could express pure-red light of 630 nm peak with a full width at half maximum of only 25.6 nm. What’s more, the color gamut of a white backlight unit based on prepared CPBI: Dy QDs glass film was 125.8 % of National Television System Committee color gamut standard and 94.0 % of Rec.2020, which has great potential in display application.

Stable Organic‐Inorganic Hybrid Sb(III) Halide Scintillator for Nonplanar Ultra‐Flexible X‐Ray Imaging

AbstractFlexible scintillator screens with excellent stability and low detection limits are crucial for X‐ray imaging applications. 0D organic metal halide materials have emerged as a strong contender in the scintillator fields, owing to their excellent optical characteristics and simple maneuverability. Herein, high‐quality and large quantities of C38H36P2Sb2Cl8 single crystals are synthesized through a simple solution approach. The prepared single crystals with dimer‐structure [Sb2Cl8]2− exhibit yellow emission with a near‐unity high photoluminescence quantum yield (PLQY) of 99.8%, and possess an exceptional light yield of 41300 photons MeV−1, and a detection limit as low as 45.6 nGyair s−1. On this basis, a large‐size and ultra‐flexible C38H36P2Sb2Cl8 scintillator utilized for X‐ray imaging is prepared by template assembled method, demonstrating a high spatial resolution of 8.15 lp mm−1. The prepared ultra‐flexible scintillator screen can achieve excellent X‐ray imaging even after multiple bending and stretching, which can also provide clear non‐planar X‐ray imaging for irregular objects. In addition, the scintillator shows excellent stability in light, heat, X‐ray irradiation, and water. These results not only expand the optoelectronic application field of organic‐inorganic hybrid antimony halides but also promote the rapid development of efficient ultra‐flexible scintillators.

Electrostatic Self‐Assembly of Ag‐NPs Mediated by Eu3+ Complexes for Physically Unclonable Function Labels

ABSTRACTPhysically unclonable functions (PUFs) are essential for anticounterfeiting. Creating high‐stability, multimode, and secure labels remains challenging. Herein, we present a novel self‐assembly method for modulating the optical signals of rare‐earth (RE) complexes via interactions with Ag nanoparticles (Ag‐NPs). Initially, we engineered a positively charged Eu3+ complex ([EuL3]3+), which promotes the self‐assembly of negatively charged Ag‐NPs to form Eu/Ag‐NPs composites. The assembly of Ag‐NPs induces a surface plasmon effect that boosts the luminescent quantum yield and Raman signal intensities, and modifies the luminescence lifetime of the [EuL3]3+. Crucially, these micron‐scale Eu/Ag‐NPs can be applied to substrates, facilitating high‐resolution signal acquisition and diverse information encoding within limited space. Validation experiments reveal that PUF labels crafted using Eu/Ag‐NPs exhibit inherent randomness and uniqueness, along with stable and repeatable signal output. The strategic self‐assembly of Ag‐NPs, mediated by [EuL3]3+, along with the effective modulation of material properties, paves the way for advancing high‐resolution, high‐information‐density solutions in anticounterfeiting technologies.

Synthesis, Structure, Spectral and Redox Properties of Phenoxazine Embedded Heteroporphyrins

A series of phenoxazine embedded heteroporphyrins containing one phenoxazine, two pyrroles and one heterocycle, such as furan, thiophene, selenophene and telluorophene, connected through four meso carbon atoms were synthesized by condensing one equivalent of phenoxazine‐based tripyrrane with one equivalent of the appropriate 2,5‐bis(hydroxymethyl‐p‐tolyl) heterocycle under acid‐catalyzed conditions, and their structure, spectral and electrochemical properties were compared with those of previously reported phenothiazine embedded heteroporphyrins. The X‐ray crystal structure of the phenoxazine embedded selenoporphyrin revealed that the selenophene ring, which is opposite phenoxazine moiety, points outward from the macrocyclic core, and the phenoxazine unit deviated by an angle of 39.47° from the mean plane defined by the four meso carbons atoms. The replacement of the phenothiazine unit in phenothiazine embedded heteroporphyrins with a phenoxazine unit led to significant alteration of the electronic properties of the macrocycles, as reflected in their spectral and electrochemical properties. The absorption spectra of phenoxazine embedded heteroporphyrins showed bathochromically shifted absorption bands, hypsochromically shifted fluorescence bands with decent quantum yields, more facile oxidation and more difficult reduction as compared to the corresponding phenothiazine embedded heteroporphyrins. DFT and TD‐DFT studies were in support of the experimental observations.

Ethyl methanesulfonate (EMS) mediated dwarfing mutation provides a basis for CaCO3 accumulation by enhancing photosynthetic performance in Ceratostigma willmottianum Stapf.

Ceratostigma willmottianum Stapf is a unique chalk gland (salt-excreting) plant from China, with a salt gland structure that excretes white crystals of calcium carbonate (CaCO3), which has potential biomineralization and carbon sequestration functions. Due to the narrow distribution of wild germplasm resources, there is a lack of diversity of new varieties to satisfy commercial development and scientific exploration. Therefore, we used ethyl methanesulfonate (EMS) mutagenesis to obtain new dwarf mutant germplasm, and analysed it in terms of morphology, growth, photosynthesis, salt glands, and excretion traits. All four dwarfing mutant strains (DM1, DM2, DM3, and DM4) exhibited extreme dwarfing (62.28%, 62.28%, 74.55% and 61.68% reduction in plant height, respectively), faster growth, increased belowground root biomass, and earlier bud differentiation and flowering. Photosynthetic capacity was enhanced: chlorophyll content, maximum quantum yield of PSII (Fv/Fm), effective quantum yield of PSII (ΦPSII), photochemical quenching coefficient (qP), electron transfer rate (ETR), net photosynthesis (Pn), intercellular CO2 concentration (Ci), stomatal conductance (Gs), and transpiration (Tr), were significantly higher in leaves of DM mutants. The density of salt glands per unit leaf area and average Ca2+ excretion rate of individual salt glands increased significantly (especially in DM2), and CaCO3 accumulation per unit leaf area was 28.57% higher than that of the wild type. Pearson correlation analysis showed that photosynthetic capacity was significantly and positively correlated with CaCO3 excretion. The above study not only provided enriched new germplasm of C. willmottianum, but also important research material for studying the mechanism of CaCO3 excretion by salt glands and carbon sequestration capacity of biomineralization.

Exciton Dissociation and Long‐Lived Delayed Components in High‐Efficiency Quasi‐Two‐Dimensional Green Perovskite Light‐Emitting Diodes

AbstractQuasi‐two‐dimensional (quasi‐2D) perovskites, consisting of multi‐quantum wells (MQWs) separated by organic intercalating cations, exhibit high luminescence efficiency while the photophysical processes involved remain partially obscure due to the uncertainty of the MQWs structure. Herein, a synergetic dual‐additive strategy is adopted to prepare quasi‐2D perovskite films, where 18‐crown‐6 and tris(4‐fluorophenyl)phosphine oxide are utilized to suppress the formation of low‐dimensional perovskites, diminish defect density, and enhance photoluminescence quantum yield to 93.7%. Notably, a long‐lived delayed component, spanning hundreds of microseconds, is identified for the first time in perovskite emitters, which correlates with exciton dissociation and recombination, and the differences in temperature‐dependent radiative lifetime of the delayed components match with the luminescence properties. Finally, benefiting from lower trap density and more efficient energy‐funneling, green PeLEDs treated with dual additives have achieved a high external quantum efficiency of 28.9% and a commendable operating half‐lifetime of 17.8 h at an initial brightness of 500 cd m−2. The observation of the long‐lived delayed components, coupled with insights into exciton dissociation, provides a profound and comprehensive understanding of the fundamental carrier behavior in perovskite emitters and establishes a direct correlation between the properties of perovskite emitters and their photophysical processes.

Carborane-based BODIPY dyes: synthesis, structural analysis, photophysics and applications

Icosahedral boron clusters-based BODIPY dyes represent a cutting-edge class of compounds that merge the unique properties of boron clusters with the exceptional fluorescence characteristics of BODIPY dyes. These kinds of molecules have garnered substantial interest due to their potential applications across various fields, mainly including optoelectronics, bioimaging, and potential use as boron carriers for Boron Neutron Capture Therapy (BNCT). Carborane clusters are known for their exceptional stability, rigid geometry, and 3D-aromaticity, while BODIPY dyes are renowned for their strong absorption, high fluorescence quantum yields, and photostability. The integration of carborane into BODIPY structures leverages the stability and versatility of carboranes while enhancing the photophysical properties of BODIPY-based fluorophores. This review explores the synthesis and structural diversity of boron clusters-based BODIPY dyes, highlighting how carborane incorporation can lead to significant changes in the electronic and optical properties of the dyes. We discuss the enhanced photophysical characteristics, such as red-shifted absorption and emission poperties, charge and electronic transfer effects, and improved cellular uptake, resulting from carborane substitution. The review also delves into the diverse applications of these compounds. In bioimaging, carborane-BODIPY dyes offer superior fluorescence properties and cellular internalization, making them ideal for cell tracking. In photodynamic therapy, (PDT) these dyes can act as potent photosensitizers capable of generating reactive oxygen species (ROS) for targeted cancer treatment making them excellent candidates for PDT. Additionally, their unique electronic properties make them suitable candidates for optoelectronic applications, including organic light-emitting diodes (OLEDs) and sensors. Overall, carborane-BODIPY dyes represent a versatile and promising class of materials with significant potential for innovation in scientific and technological applications. This review aims to provide a comprehensive overview of the current state of research on carborane-BODIPY dyes, highlighting their synthesis, properties, and broad application spectrum.

In-situ spontaneous emission control of MoSe₂-WSe₂ interlayer excitons with high quantum yield

In-situ spontaneous emission control of MoSe₂-WSe₂ interlayer excitons with high quantum yield

Multiple Resonance Quasi‐fluorescence from BN‐Doped Aromatic Compounds Modified with “Naphthalene” Units Approaches the BT.2020 Green Light Standard

AbstractDeveloping fluorophores that conform to the Broadcast Service Television 2020 (BT.2020) standard presents a formidable challenge. Here, we propose an innovative approach that integrates two and three‐boron/nitrogen (BN2)‐embedded [4]helicene subunits with naphthalene, resulting in the synthesis of two novel narrowband bright green quasi‐fluorescent emitters, NT‐2B and NT‐3B for ultra‐high‐definition displays. These emitters exhibit minimal reorganization energy and Huang–Rhys factor, emitting at 510 and 511 nm in dilute toluene solution with exceptionally narrow full width at half maximum values of 15 and 14 nm, respectively. Notably, NT‐2B demonstrates an impressive photoluminescence quantum yield of 92.5 %, rapid radiative decay rate, and slow non‐radiative decay rate. Owing to their narrowband emission characteristics and outstanding optoelectronic properties, corresponding OLEDs based on NT‐2B demonstrate a high external quantum efficiency of 30.6 %, with an FWHM value of 21.5 nm and a CIEy of 0.74, positioning it as one of the leading narrow‐band green emitters.

Exploring the Interplay of Wavelength, Quantum Yield, and Penetration Depth in In Vivo Fluorescence Imaging.

The intricate interplay between the irradiation wavelength, the fluorophore quantum yield (QY) and penetration depth profoundly influences the efficacy of in vivo fluorescence imaging in various applications. Understanding the complex behavior of fluorescence in vivo, specifically how variations in wavelength affect the QY of commonly used dyes and the depth of imaging is crucial for optimizing fluorescence imaging techniques, as it directly impacts the accuracy and efficiency of imaging in biological tissues. In our study, we explore these dynamics through Monte Carlo simulations conducted under conditions reflective of wide-field fluorescence imaging, examining how variations in wavelength impact the dye's QY and depth of imaging, and consequently, the fluorescence behavior. A transition in the exponential decay of the emission depth exponent is observed around the 500-600nm range, indicating varying degrees of influence of depth on the fluorescence emission. The analysis of the fluorophore's QY reveals wavelength-dependent variations, with the most significant impact observed in the 600-700nm range. Moreover, we continued our investigation to explore multiplexing, unveiling insights into the spacing between identical spots in multiplexing images across various depths and wavelengths.

Flavin–Iodine‐Catalyzed Aerobic Oxidative Tandem C(sp3)−H Imination and Amination: Synthesis of Fluorescent Imidazo[1,5‐a]pyridines from Pyridylmethanes and Aminomethanes

AbstractAerobic oxidative tandem C(sp3)−H imination and amination between pyridylmethane and aminomethane derivatives was demonstrated using a flavin–iodine‐coupled catalyst. This method provides a simple and atom‐economical synthesis of various 1,3‐substituted imidazo[1,5‐a]pyridines with fluorescent properties. The flavin–iodine catalyst efficiently promoted multiple reactions, including the oxygenation of pyridylmethane and subsequent oxidative C−N bond formation, utilizing only molecular oxygen, which is a sustainable ideal oxidant. The resulting 1‐ester‐substituted imidazo[1,5‐a]pyridine derivatives exhibited dual‐state emission in both solution and solid states. In particular, imidazo[1,5‐a]pyridine with a bulky 2,6‐dichlorophenyl substituent showed an apparent blue emission with good photoluminescence (PL) quantum yields (0.49 in CH2Cl2 solution and 0.39 in the solid state), making it promising candidate for use in optoelectronic devices.

Enhanced Asymmetric Circularly Polarized Luminescence in Self-Organized Helical Superstructures Enabled by Macro-Chiral Liquid Crystal Quantum Dots.

Circularly polarized luminescent (CPL) materials have garnered considerable interest for a variety of advanced optical applications including 3D imaging, data encryption, and asymmetric catalysis. However, the development of high-performance CPL has been hindered by the absence of simple synthetic methods for chiral luminescent emitters that exhibit both high quantum yields and dissymmetry factors. In this study, we present an innovative approach for the synthesis of macro-chiral liquid crystal quantum dots (Ch-QDs/LC) and their CPL performance enhancement through doping with 4-cyano-4'-pentylbiphenyl (5CB), thus yielding a CPL-emitting generator (CEG). The Ch-QDs/LCs were synthesized, and their surfaces functionalized with a chiral mesogenic ligand, specifically cholesteryl benzoate, anchored via a lipoic acid linker. Under the regulation of chiral 2S-Zn2+ coordination complexes, the chiral LC encapsulation process promotes coordinated ligand substitution, resulting in an exceptional quantum yield of 56.3%. This is accompanied by high absorption dissymmetry factor (gabs) and luminescence dissymmetry factor (glum) values ranging from 10-3 to 10-2, surpassing most reported dissymmetry factors by at least an order of magnitude. The modular Ch-QDs/LCs demonstrate the ability to transfer chirality to the surrounding medium efficiently and manifest macro-chiral characteristics within a nematic LC matrix. Utilizing Ch-QDs/LC as an effective CPL emitter within achiral 5CB matrices enabled the system to achieve a maximum glum value of 0.35. The resultant CEG device acted as a direct CPL source, initiating enantioselective photopolymerization.

Tetraphenylethene-Containing Nanofilm via Interfacial Confinement Self-Assembly for Fluorescent Monitoring of SOCl2 Leakage in a Li-SOCl2 Battery Electrolyte.

Lithium thionyl chloride (Li-SOCl2) batteries are widely used due to their high energy density and long shelf life. However, the corrosive nature of SOCl2 poses a safety hazard, necessitating effective leak detection methods. We report an approach for real-time fluorescent detection of SOCl2 leakage in Li-SOCl2 batteries using a tetraphenylethene-based nanofilm. The nanofilms were prepared through the interfacial confined self-assembly method and exhibit excellent flexibility, homogeneity, tunable size and thickness, and adaptability to various substrates, enabling easy integration into sensor devices. They possess high photochemical stability and a photoluminescence quantum yield exceeding 25%, demonstrating their potential as high-performance fluorescent sensing material. The nanofilms also exhibit high sensitivity, good reproducibility, and selectivity toward SOCl2 detection. Upon exposure to SOCl2 vapor, the nanofilm shows a red-shifted and fluorescence quenching response, attributed to the protonation of the acylhydrazone bond in the nanofilm by the hydrolysis product of SOCl2, which disrupts the electronic structure of the nanofilm and leads to a decrease in the fluorescence intensity and a shift in the emission wavelength. A detection limit of ∼1.31 ppt and excellent repeatability over 300 cycles are demonstrated, highlighting their high sensitivity and reliability. This work paves the way for a highly sensitive and reliable leak detection system for Li-SOCl2 batteries, enhancing their safety and reliability in various applications.

Construction of Freezing Injury Grade Index for Nanfeng Tangerine Plants Based on Physiological and Biochemical Parameters.

Low-temperature freezing stress constitutes the most significant meteorological disaster during the overwintering period in the Nanfeng Tangerine (NT) production area, severely impacting the normal growth and development of the plants. Currently, the accuracy of meteorological disaster warnings and forecasts for NT orchards remains suboptimal, primarily due to the absence of quantitative meteorological indicators for low-temperature freezing stress. Therefore, this study employed NT plants as experimental subjects and conducted controlled treatment experiments under varying intensities of low-temperature freezing stress (0 °C, -2 °C, -5 °C, -7 °C, and -9 °C) and durations (1 h, 4 h, and 7 h). Subsequently, physiological and biochemical parameters were measured, including photosynthetic parameters, chlorophyll fluorescence parameters, reactive oxygen species, osmoregulatory substances, and antioxidant enzyme activities in NT plants. The results demonstrated that low-temperature freezing stress adversely affected the photosynthetic system of NT plants, disrupted the dynamic equilibrium of the antioxidant system, and compromised cellular stability. The severity of freezing damage increased with decreasing temperature and prolonged exposure. Chlorophyll (a/b) ratio (Chl (a/b)), maximum quantum yield of photosystem II (Fv/Fm), soluble sugar, and malondialdehyde (MDA) were identified as key indicators for assessing physiological and biochemical changes in NT plants. Utilizing these four parameters, a comprehensive score (CS) model of freezing damage was developed to quantitatively evaluate the growth status of NT plants across varying low-temperature freezing damage gradients and durations. Subsequently, the freezing damage grade index for NT plants during the overwintering period was established. Specifically, Level 1 for CS ≤ -0.50, Level 2 for -0.5 < CS ≤ 0, Level 3 for 0 < CS ≤ 0.5, and Level 4 for 0.5 < CS. The research results provide valuable data for agricultural meteorological departments to carry out disaster monitoring, early warning, and prevention and control.

AIE-derived fluorescent silsesquioxane-based hybrid aerogel for light-enhanced gold recovery

In this work, two aggregation-induced emission (AIE)-active organic fluorescent monomers (TPV, TPC) were synthesized by Knoevenagel reaction of 2,2′-([1,1′-biphenyl]-4,4′-diyl)diacetonitrile with benzaldehyde and 4-bromobenzaldehyde, respectively. Subsequently, two fluorescent hybrid porous polymers with semiconductor performance (PCS-TPV, PCS-TPC) were prepared successfully by connecting octavinyl silsesquioxane (OVS) with TPV and TPC through Friedel-Crafts reaction and Heck coupling, respectively. Among them, PCS-TPV with a hyper-crosslinked structure offered a specific surface area of up to 1165 m2 g−1; PCS-TPC was the first AIE-derived fluorescent hybrid silsesquioxane-based semiconductor polymer with 3-D conjugated structure. Compared with PCS-TPV, PCS-TPC exhibited stronger visible light absorption, higher fluorescent performance and quantum yield due to its high AIE-active unit content. Besides, PCS-TPC exhibited a remarkable gold recovery capacity (Qm = 2728 mg g−1) when exposed to visible light irradiation. Adsorption mechanism revealed that the photoelectrons produced by PCS-TPC under visible light irradiation reduced all adsorbed Au(III) to Au(I) and Au(0). Furthermore, a hybrid aerogel was prepared through physical blending of PCS-TPC with chitosan, overcoming the limitation that insoluble powder was difficult to process and recycle. This work provided a very efficient, sustainable, and industrially feasible way for gold recovery in e-waste.

Absorption, Fluorescence, and Two-Photon Excitation Ability of 5-o-Tolyl-11 (or 13)-o-tolylisoindolo[2,1-a]quinolines Prepared by Ring-Closing Metathesis and [2+3] Cycloaddition.

We have successfully improved the fluorescence quantum yield of isoindolo[2,1-a]quinoline derivatives by suppressing the rotation of the phenyl groups at positions 5 and 11 (or 13). Additionally, we found that the planarity of these phenyl groups at positions 5 and 13 of isoindolo[2,1-a]quinoline derivatives is crucial for two-photon absorption properties.

Synthesis of Side-Chain Liquid Crystalline Polyacrylates with Bridged Stilbene Mesogens.

In recent years, π-conjugated liquid crystalline molecules with optoelectronic functionalities have garnered considerable attention, and integrating these molecules into side-chain liquid crystalline polymers (SCLCPs) holds potential for developing devices that are operational near room temperature. However, it is difficult to design SCLCPs with excellent processability because liquid crystalline mesogens are rigid rods, have low solubility in organic solvents, and have a high isotropization temperature. Recently, we developed near-room-temperature π-conjugated nematic liquid crystals based on "bridged stilbene". In this work, we synthesized a polyacrylate SCLCP incorporating a bridged stilbene that exhibited a nematic phase near room temperature and could maintain liquid crystallinity for more than three months. We conducted a thorough phase structure analysis and evaluated the optical properties. The birefringence values of the resulting polymers were higher than those of the corresponding monomers because of the enhanced order parameters due to the polymer effect. In addition, the synthesized polymers inherited mesogen-derived AIE properties, with high quantum yields (Φfl = 0.14-0.35) in the solid state. It is noteworthy that the maximum fluorescence wavelength exhibited a redshift of greater than 27 nm as a consequence of film formation. Thus, several unique characteristics of the SCLCPs are unattainable with small molecular systems.

Lead‐free Halide Perovskites With ≈100% PLQY and Dual‐Color Emission for White Light‐Emitting Diodes

AbstractLead‐free halide perovskites (LHP) have attracted extensive attention in the field of next‐generation solid‐state lighting. However, single perovskite phosphor with tunable white‐light emission and ultra‐high photoluminescence quantum yield (PLQY) are rare. Here, the tunable dual‐color emission LHP phosphor is developed with a near‐unity PLQY of 99.5%. The LHP phosphor comprises Cs2NaInCl6: Sb3+/Bi3+ and Cs2InCl5·H2O: Sb3+/Bi3+ crystals, with the transition between these two perovskite structures being adjustable by the concentration of Na+. The addition of NaCl inhibits the hydrolysis of the [Sb(H2O)Cl5]2− octahedron, resulting in 3D connected [SbCl6]3− octahedron with less Jahn‐Teller distortion, and the PLQY of LHP is greater than 90%. Finally, the white‐light diode device is fabricated by assembling the LHP with a ultraviolet light‐emitting diode chip and the white light‐emitting diode device achieved Commission Internationale de l'Eclairage color coordinates of (0.34, 0.33), correlated color temperature of 4936 K, and a high color rendering index of 92.9. The LHP perovskite exhibited multimodal luminescence when excited by 365, 335, and 310 nm UV light, showing the multi‐mode anti‐counterfeiting capabilities of the LHP crystals.