Sub-bandgap electroluminescence (EL) enables energy-efficient operation in light-emitting devices, yet its mechanisms remain incompletely understood in perovskite systems. Here, we study cesium lead halide perovskite light-emitting diodes (PeLEDs) with different quantum dot (QD) sizes and find that ultra-small QDs exhibit lower turn-on voltage of 1.31 V (73% of the bandgap). This behavior arises from suppressed quantum confinement Stark effect, which promotes hole injection and extends hot-carrier lifetimes due to the phonon bottleneck effect, thus facilitating sub-bandgap turn-on. These results establish quantum dot size as a key factor governing sub-bandgap emission in PeLEDs and provide guidance for designing more efficient perovskite optoelectronics.

Metal nanoclusters (NCs) are attracting increasing attention for their molecule-like photoluminescence (PL) properties, while achieving emission tuning remains a challenge. Here, we report the solvation-triggered isomerization of surface terminations and modulation of electron transfer dynamics in the 6-mercaptopurine-9-β-D-ribofuranoside (6-MPR)-protected gold NCs, to attain a controllable emission spanning widely from 495 nm sky-blue to 800 nm near-infrared light. Specifically, the isomerization of 6-MPR gives Au(I)-thione isomer terminals (i.e., R1 domain) and Au(I)-thiol isomer terminals (i.e., R2 domain), confers the gold NCs with two prominent emission bands at 590 nm (i.e., PL I from the electron transfer emission state) and 770 nm (i.e., PL II from the triplet state), respectively. The further solvation of gold NCs is rationally designed by mapping out fourteen different organic solvents into four categories referring to their inherent properties of viscosity, polarity, coordination ability, and the strength of proton-giving capacity. This allows for rational conversion between R1 and R2 domains, and is concurrent with modulation of the proton-coupled electron transfer dynamics and thus customizable emission tuning.

Molecular additives are frequently employed to enhance the performance of perovskite light-emitting diodes (PeLEDs), either through surface defect passivation or crystal growth control. In general, such passivation is attained through the chelation of the molecular additive to a defective Pb site along a lattice plane. Unfortunately, nano-crystallites often display multiple lattice planes and defects that a single additive is inadequate in passivating. Here, we report a dual additive system, comprising 5-aminopentanoic acid and (4-fluoropheny)thiourea to enhance the performance of FAPbI3 PeLEDs. Our results and calculations reveal that the dual additives chelate cooperatively and synergistically with defective sites along the (100), (110) and (111) lattice planes, leading to significantly improved performance compared to the use of a single additive. The strong binding of the dual additives towards multiple lattice planes further slows down the growth of the nucleated crystallites, leading to small and uniform crystal grains as well as smoother thin films that exhibit higher exciton binding energy and improved luminescence quantum yields. The resulting PeLEDs attained a peak external quantum efficiency (EQE) of 26.3% at a high current density of 298 mA·cm-2 and a peak radiance of 1843 W·sr-1·m-2 at 795 nm. Such high efficiency and radiance, together with enhanced stability, could allow PeLEDs to become viable for commercial use.

Quasi-two-dimensional (quasi-2D) perovskites have attracted extraordinary attention due to their favorable energy funnel structures and outstanding optical performance. However, the development of large-area red perovskite light-emitting diodes (PeLEDs), a crucial component of light sources, has been constrained by suboptimal film quality as the large-area perovskite films prepared using the anti-solvent strategy exhibit severe phase separation, morphological inhomogeneity, and uneven light emission. Herein, by correlating the physicochemical properties of common solvents (boiling point, saturated vapor pressure, and molecular parameters) with perovskite film quality, we identify dimethylformamide (DMF) as the optimal solvent to replace the conventional dimethyl sulfoxide (DMSO)/anti-solvent system to fabricate high-quality large-area red quasi-2D perovskite films with uniform brightness and morphology. DMF-based red PeLEDs achieve peak external quantum efficiencies of 15.06% (1 cm2) and 7.50% (9 cm2), with corresponding maximum luminance of 1145.90 and 159.05 cd m-2, significantly outperforming anti-solvent-processed devices using DMSO. Furthermore, we adapt this strategy to blade-coating (a scalable process incompatible with anti-solvent) by selecting the 2-MP/ DMF co-solvent system that enables the fabrication of even larger-area uniform perovskite films. This work reveals that rational solvent design can effectively address the inherent drawbacks of antisolvent processing, offering a feasible strategy for the scalable fabrication of high-performance red quasi-2D PeLEDs.

Lanthanide-based upconversion aerogels (UCAs) hold considerable promise for a variety of applications, including anti-counterfeiting, temperature sensing, and photoelectric devices. However, their potential is heavily hindered by the limitations of luminescent designability and functional versatility. Herein, we demonstrate the fabrication of self-supporting UCAs with customizable components and properties through a freeze-drying method using K2YF5-based upconversion nanowires as building blocks. The UCAs can function as an optical thermometer during their applications, such as thermal insulation. Moreover, the UCAs, mainly formed through ligand-mediated assembly of the nanowires, possess sectional adjustability and can accommodate other nanomaterials as functional dopants, exhibiting potential applications in multiplexed barcoding and water-resistant phosphor. Given the high tunability of the UCAs and tremendous functional nanomaterials, these results should shed light on arbitrary UCAs for diverse applications.

Metal nanoclusters, as unique metallic molecules comprising a few to hundreds of metal atoms and stabilized by organic monolayer ligands, have recently emerged as a novel class of chromophores and hold great promise for flexible light-emitting diodes. However, the fabrication of flexible metal nanoclusters-based light-emitting diodes is still hindered by low photoluminescence quantum yields, suboptimal solution processability, and consequently compromised emitter-film quality with random dipole orientations. This work addresses these limitations through strategic molecular engineering by employing 1, 3-di(9H-carbazol-9-yl)benzene as a π-conjugated mediator. This approach enables supramolecular assembly to achieve π-π coupling-mediated horizontal dipole alignment in nanocluster solid films, allowing an external quantum efficiency of up to 26.4% in flexible light-emitting diodes with a maximum brightness of 41,365 cd m-2, and retaining more than 94% of initial efficiency after 2000 bending cycles at 3 mm curvature radius.

Night driving constitutes a critical scenario in transportation safety, where driver fatigue represents a major factor inducing traffic accidents. Current strategies for relieving driver fatigue via physiological regulation are still insufficient and limited in practical application. In this work, based on the luminescent and physiological effects of light, we design a composite lighting scheme consisting of near-infrared and visible light to alleviate driver fatigue during night driving. The driver’s facial images are recorded by a camera, and the percentage of eye closure (PERCLOS) is calculated and analyzed in real time using a ZYNQ-7000 development board, which further enables the dynamic regulation of the lighting mode. Compared with the pure visible light illumination, the introduction of near-infrared light prolongs the average safe driving time by 1.31 times and decreases the average PERCLOS value by 0.01. This work provides a promising lighting strategy based on luminescence regulation for improving driving safety and reducing driver fatigue.

Photoplethysmography (PPG) sensors play a vital role in human health monitoring, particularly for blood oxygen saturation and heart rate detection. However, the measurement accuracy of PPG sensors remains constrained by light source chromatic purity, hindering their broader application. Here, we employ high-color-purity perovskite materials with an optimally designed device to construct a PPG sensor, successfully enabling real-time monitoring of blood oxygen saturation and heart rate. Through device performance optimization, we discovered that high-purity green light generates more effective signals, thereby enhancing Peripheral Oxygen Saturation (SpO2) measurement accuracy. Consequently, our PPG sensor demonstrates repeatability and high accuracy comparable to commercial blood oxygen and heart rate monitors. This work not only demonstrates that high color purity enhances the testing accuracy of SpO2, thereby paving new avenues for the fabrication of high-precision PPG sensors, but more significantly, it broadens the application scope of perovskite LEDs in the field of health monitoring.

Electrode materials made of supercapacitors have obvious capacity attenuation caused by ion diffusion retardation and insufficient conductivity during high-rate charge and discharge, which seriously restricts the practical application of high-power supercapacitors. In this study, a hierarchical structure of the ZnCoNi LDH@MXene (ZCN LDH@M) electrode material was successfully constructed using a cascade strategy of "solvent-mediated template-etching-recombination". A rhombic dodecahedron ZnCo-ZIF (50-100 nm) with large mesopores and small size was synthesized on the ZnO nanoflower template, and then ZCN LDH nanosheets were grown in situ on the MXene substrate to obtain petal-shaped ZCN LDH@M composites. Compared with the ZnCoNi LDH electrode (69.1%), the composite showed better performance at a current density of 10 A g-1, and its capacity retention rate reached 77.8%. At the same time, the specific capacitance measured at 1 A g-1 was 1414 F g-1. A high energy density of 45.6 Wh kg-1 was achieved at 750 W kg-1 using the constructed ZCN LDH@M//activated carbon (AC) asymmetric supercapacitor (ASC), which utilized a redox-augmented electrolyte consisting of 6 M KOH + 0.03 M K3[Fe(CN)6]. The unique composition and hierarchical structure of the obtained ZnCoNi LDH@MXene are expected to significantly enhance its electrochemical activity and performance.

PbSe colloidal quantum dots (CQDs) have emerged as a popular research subject in optoelectronic devices because of their tunable luminescence in the near-infrared (NIR) region. However, intrinsic defects generated during their synthesis make it challenging to obtain chemically stable and highly efficient PbSe CQDs. In this work, we demonstrate an effective passivation strategy using phenethylammonium chloride (PEACl) additives that form a robust Pb-Cl protective layer on the surface of PbSe CQDs. This approach boosts the photoluminescence quantum yield (PLQY) from 25.7% to 46.1% and enhances the air and thermal stabilities of PbSe CQDs. We have successfully fabricated high-performance phosphorescence conversion light-emitting diode (PC-LED) devices based on defect-passivated quantum dots. These PC-LEDs achieve a peak external quantum efficiency (EQE) of 2.88% at a low drive voltage of 2.08 V, demonstrating excellent photoconversion performance and holding significant application potential in the field of nondestructive optical inspection and food quality sensing.

The pivotal challenge in elevating the energy density of asymmetric supercapacitors (ASCs) hinges on the breakthrough of anode performance and its synergistic compatibility with cathodes. Herein, we report an in-situ thermal conversion strategy for transforming Cu-Bi-Co Prussian blue analogues (CuBiCo-PBAs) synthesized under mild hydrothermal conditions into CuBi2O4@Co3O4 heterojunctions, a design that integrates the structural advantages of Prussian Blue Analogues (PBAs) with the electronic synergism of multi-metallic oxides. The introduction of Bi3+ tailors a unique coordination environment in PBAs, enabling the in-situ formation of core-shell heterojunctions during thermal treatment. This architecture not only enhances electron conduction via interfacial charge transfer but also facilitates ion diffusion through interconnected pore networks. Benefiting from this structural advantage, the CuBi2O4@Co3O4 heterojunction, when used as an anode material, delivers a high specific capacitance of 952F center dot g-1 (831F center dot g-1) at 1 A center dot g-1 (10 A center dot g-1). An assembled NCS//CuBi2O4@Co3O4 asymmetric supercapacitors (ASC) constructed with Ni1.5Co1.5S4 (NCS) as the cathode material achieves an energy density of 52.34 Wh center dot kg-1 at 745 W center dot kg-1 and retains 78.31 % capacity after 3000 cycles at 10 A center dot g-1, demonstrating its potential for practical energy storage. Thus, the findings of this study offer a viable approach for the further development of asymmetric supercapacitors featuring ultrahigh energy density.

The core-skeleton braced low-frequency acoustic responses, linked to mechanical vibrations, are vital for the reactivity and functionality of a few-nanometer metal nanoclusters (NCs). Yet, how core-structure-dependent acoustic vibrations impact and enhance the luminescence of metal NCs is not fully understood. Using a programmable total-structure approach, we studied a series of Au25 NCs, focusing on core symmetry manipulation by altering the shape, stacking patterns, and composition of the icosahedral Au13 core to disrupt its spherical distribution. Our results show that breaking core symmetry softens electron-acoustic phonon coupling, thereby enhancing luminescence in NCs. As the Au13 core deviates from a spherical shape, the frequency and intensity of the radial breathing acoustic mode decrease, and in sequential lower-frequency quadrupolar and torsional acoustic modes play a reduced role in non-radiative relaxation. Of note, the core symmetry breaking also redistributes optical phonons, shifting the balance toward non-radiative dominance. We emphasize that vibrational quenching of electrons in the luminescent state significantly limits NC emission, although electron loss and transfer at higher energies also remain important. These findings offer novel strategies for enhancing luminescence through structural regulation and inspire further exploration of total-structure suppression and engineering to optimize NC optical performance.

While white light-emitting diodes (LEDs) based on metal nanoclusters (NCs) are currently widely desired, due to limitations in the difficulty of controlling emission wavelengths and the susceptibility of luminescence performance to external influences, metal NC white light-emitting diodes (WLEDs) are still not sufficiently developed. In this regard, we employed the bimetallic alkynyl clusters [Au6Ag2(C2C13H11O)6(PPh2C4H8PPh2)3](ClO4)2 (i.e., Au6Ag2 NCs) incorporated with 4,4',4″-tris(carbazol-9-yl)-triphenylamine (TCTA) as a multifunctional ligand that serves to construct new luminescent centers and reduce film defects to achieve single emissive layer (SEL) WLEDs. As a result, the optimal SEL WLEDs achieve a maximum external quantum efficiency of 7.3% and a peak luminance of 1038 cd/m2 with a color rendering index of 93, which represents the high performance of the SEL WLEDs in inorganic materials. This work exemplifies the success of the metal NCs involved in WLEDs and offers a simple yet effective strategy to demonstrate high-performance metal NC WLEDs.

Quasi-two-dimensional (quasi-2D) perovskites have attracted considerable interest owing to their exceptional optical characteristics. However, the introduction of long-chain organic cations leads to inhomogeneous phase distributions and high defect densities, which in turn lead to incomplete energy transfer and more non-radiative recombination centers due to uncontrolled crystallization processes and enhanced quantum confinement effects. Here, we employed a multifunctional methoxy-methyl (diphenyl) phosphine oxide molecule, which exhibits a bifunctional effect to solve the above issues. It not only regulates the n-phase distribution, inhibiting the small-n phase and promoting the generation of the large one, but also passivates defects via P = O coordination. Consequently, the optimized device achieved an external quantum efficiency (EQE) of 24.13% and a peak luminance of 156,138.42 cd m-2, ranking among the highest reported values to date. This strategy offers a novel route to concurrently narrow the phase distribution and reduce the defect in quasi-2D perovskites, enabling highly efficient green PeLEDs.

Abstract A high-efficient and broadband near-infrared light source is the key to achieving high-sensitivity detection of agricultural products. However, there is still a challenge in developing the light source that can provide high-intensity, uniform and stable output over a very wide spectral range. Herein, the ideal LED light source was prepared by mixing two different sizes of PbSe quantum dots (QDs) with SBA-15 mesoporous particles to achieve an ultra-wide spectral range from 900 to 1800 nm. Furthermore, this LED was used to analyze the soluble solids content (SSC) of apple slice samples, effectively enhancing the precision of the detection system. This study demonstrates that PbSe/SBA-15 LEDs hold significant potential for infrared detection in agricultural products.

The main challenge for high-performance hybrid supercapacitor (HSC) development is the design of electrode materials possessing both ideal microstructures and adjustable defect properties. In this study, CoNi layered double hydroxide with oxygen vacancy (OV-CoNi-LDH) microspheres were successfully synthesized as cathode materials through a conformal transformation strategy. Attributed to the unique hierarchical porous framework of the material, which facilitates efficient electrolyte ion diffusion and rapid charge transfer, the electrochemical specific capacitance is significantly boosted to 1169 F g-1 (1 A g-1). Theoretical calculations based on density functional theory (DFT) further reveal a synergistic effect between the heterointerface and defect structure in optimizing the electronic structure. This electronic structure optimization significantly enhances the adsorption affinity of OV-CoNi-LDH for OH- ions and improves the reaction kinetics of the electrode process. A high energy density of 45.51 to 24.89 Wh kg-1 was delivered by the OV-CoNi-LDH//activated carbon (AC) HSC, with corresponding power densities between 800 and 8000 W kg-1. By integrating the OH- adsorption energy in DFT calculations with the density of states (DOS) analysis, this study reveals the fundamental mechanism through which oxygen vacancies enhance reaction kinetics. This enhancement occurs by reducing the OH- adsorption energy barrier and increasing electron density near the Fermi level. These findings provide valuable theoretical guidance for the design of high-performance electrode materials for hybrid supercapacitors.

Stannate perovskites (MSnO3), benefiting from their high production of HCOOH and the perovskite structure-enabled tunability of properties, are emerging as promising catalysts for electrochemical CO2 reduction (CO2R). However, optimizing the catalytic performance of MSnO3 for CO2R remains largely unexplored. Here, we systematically study the catalytic performance of MSnO3 with a distinct A-site cation, M (M = Ba, Sr, and Ca), for CO2R. Our experimental results show that the M cation dramatically affects the catalytic performance, especially the selectivity and stability. In particular, the CaSnO3-based catalyst exhibits the highest selectivity to HCOOH and stability but the lowest activity. Further theoretical investigations reveal that the A-site cation can affect the selectivity of MSnO3 for the CO2R reaction and may impact the stability of MSnO3. Both experimental and theoretical findings reveal that stannate perovskites can be effective and selective catalysts for CO2R, while their stability needs to be considered carefully. These results should shed light on the rational design of perovskite catalysts with desired performance for CO2R.

Electromagnetic wave radiation disrupts electronic devices and threatens human health. Microwave absorbing materials are essential for addressing electromagnetic pollution and military stealth applications. Advancement of electronics creates demand for absorbers with thin thickness, light weight, wide bandwidth, and strong absorption. Conventional materials suffer from poor impedance matching and limited loss mechanisms in the Ku band. Heterojunction engineering offers solutions through control of band alignment and charge distribution. The built-in electric field serves as a core mechanism for enhancing dielectric loss. However, limitations exist in understanding of formation mechanisms of built-in electric fields in multi-interface systems. This study develops a ZnNiCo-LDH/MXene composite with coral-inspired architecture. Construction of high-density Mottu2013Schottky interfaces occurs through electrostatic assembly of polar semiconductor units and conductive matrices. Vertical growth of flower-like layered double hydroxide (LDH) on MXene extends propagation paths of electromagnetic waves. This design creates continuous networks of built-in electric fields. Enhanced charge separation and interfacial polarization result. Performance demonstrates u221249.6 dB reflection loss at 1.35 mm thickness. Effective bandwidth reaches 3.4 GHz across Ku-band frequencies. Radar cross-section simulations confirm u221239.57 dBu00B7m2 signal suppression. These achievements meet requirements of advanced absorbers. The work establishes a new paradigm for manipulation of built-in electric fields through multi-interface engineering.

Construction of donor-acceptor (D-A) structure in g-C3N4 is an effective strategy to accelerate charge carrier dynamics for enhanced photocatalytic hydrogen production. However, current D-A structured g-C3N4 exhibits low Brunauer-Emmett-Teller (BET) surface areas and insufficient active sites owing to simple molecular and spatial structure of incorporated donor or acceptor moieties. To build a D-A configured g-C3N4 with abundant active sites, the electron-donating 9,9 '-spirobifluorene motif with four benzene rings and large steric hinderance was grafted onto g-C3N4 (denoted as CN-D) via surface engineering approach. Accordingly, the BET surface area of CN-D ramped up to 88.62 m2 center dot g-1 from 44.93 m2 center dot g-1 of pristine g-C3N4 (denoted as CN), suggesting more active sites and shorter diffusion distance of charge carriers over CN-D. Furthermore, the exciton binding energy of CN-D was reduced to 84.85 meV from original 111.80 meV of CN, facilitating generation of more free electrons. Furthermore, an ultrafast intramolecular charge transfer state with a lifetime of 156.0 fs was observed in CN-D photocatalyst. Consequently, the photocatalytic hydrogen evolution rate of CN-D revealed 33.74 mu mol & sdot;h-1, nearly 2.74 times higher than that of CN, demonstrates the synergistic effect of increasing active sites and accelerating charge carrier dynamics on D-A structured g-C3N4.

Supercapacitors, with remarkable advantages such as excellent power density, extremely short charging and discharging times, and an ultra-long cycle life, exhibit great application potential within the realm of energy storage. However, the bottleneck issue of their relatively low energy density has become a key factor restricting their in-depth application in a wider range of fields and further development, and effective solutions are urgently needed. In this paper, a sacrificial template method and an electrostatic self-assembly strategy were employed to controllably synthesize the mulberry-layered cubic composite electrode material Cu2O@NiCo-LDH/Mxene (Cu2O@NCL/M). In this material, a part of the residual Cu2O template exhibits certain redox activity and can undergo reversible redox reactions during the electrochemical process, thereby providing additional capacitance contributions. The cubic structure remaining after etching itself has a high degree of symmetry and stability, and the mulberry-like assembly method enables the nanosheets of the layered double hydroxide (LDH) to support each other. The introduction of a single layer of Mxene can not only promote the electron transfer between Cu2O and NiCo-LDH, but also the interfacial interaction among the three components is advantageous for improving the structural stability, enabling it to maintain good electrochemical performance during charge-discharge processes. The specific capacitance of Cu2O@NCL/M is 1713F center dot g-1 (at 1 A center dot g-1). Cu2O@NCL/M exhibits remarkable rate performance, maintaining 82.3 % of its capacitance as the current density increases to 10 A center dot g-1. Moreover, after undergoing 5000 cycles, it demonstrates impressive long-term stability by retaining 80 % of its initial specific capacitance. Interestingly, the energy density of the asymmetric supercapacitors (ASCs) Cu2O@NCL/M//AC can be significantly increased to 49.5 Wh center dot kg-1 (with a power density of 750 W center dot kg-1) and 45.0 Wh center dot kg-1 (with a power density of 700 W center dot kg-1). Therefore, this work demonstrates a simple and successful synthetic approach for fabricating high-performance energy storage devices with special morphology.