The realization of low-power-consumption organic light-emitting diodes (OLEDs) with high power-efficiency (PE) and stable lifetimes hinges on developing high-conductivity electron-transport. However, traditional electron-transport materials (ETMs) are confined by low electron mobility and intrinsic defect states, while the n-doping technique still faces poor stability problems. Herein, we synergistically propose coordination-competition-free electron-donating modification and coordination-activated trap filling (CATF) strategies that involves alkyl-modified tetradentate-phenanthroline organometallic complexes to construct a high-conductivity electron-transport layer. The CATF mechanism pre-fills defect states within the material via an in-situ coordination-activated silver ionization, while the alkyl electron-donating group enhances the nucleophilicity of chelating sites by avoiding heteroatom coordination competition, and eliminates interfacial injection barriers, maximizing the coordination-activated ionization efficiency for boosting conductivity to 4.65×10 − 5 S/m. Proof-of-concept pure-green OLEDs based on thermally activated delayed fluorescence sensitizers exhibited an excellent maximum PE of 170.1 lm/W and a long-term T95 lifetime of 6450 h at 1000 cd/m 2 (322.1 lm/W and 10660 h in top-emitting architectures), correspondingly showing 28% and 47% improvements compared to state-of-the-art ETMs. These findings provide innovative insights into material design and mechanisms to address the electron-transport bottleneck, providing strategic guidelines for designing low-power‑consumption OLEDs.

Abstract o ‐Carborane is widely used in designing multifunctional organic luminescent emitters. However, these derivatives often suffer from inefficient exciton utilization and competing energy pathways, leading to poor electroluminescent performance. In this study, two multifunctional materials, DBN‐ o Cb and DBN‐ o Cb‐2, were synthesized by embedding blue‐ and green‐emitting boron/nitrogen multiple resonance (B/N‐MR) units into ortho ‐carborane scaffolds. Exciton dynamics analysis showed that the localized excitation energy of DBN‐ o Cb could be effectively transferred via the Förster resonance energy transfer process, avoiding competition with photoinduced electron transfer. The rigid structures, formed by B/N‐MR fragments and o ‐carborane units, help reduce non‐radiative decay. Further investigation of exciton dynamics through femtosecond transient absorption studies indicates the presence of multiple distinct energy transfer pathways for DBN‐ o Cb. The corresponding organic light‐emitting diode based on DBN‐ o Cb achieved a record external quantum efficiency of 22.3%, the highest reported for red‐organic light‐emitting diodes with o ‐carborane‐based emitters.

Green, one of the three primary colors, plays a crucial role in electroluminescent (EL) devices, making green EL materials a vital component of organic light-emitting diodes (OLEDs). However, to date, there has been no systematic review specifically focusing on the research progress of green EL materials. In this review, we have not aimed to list narrow-band green EL materials exhaustively. Instead, our main goal is to provide a focused, in-depth analysis that highlights the essential role of green emitters in modern optoelectronic technology. We systematically examine the core design strategies underlying high-performance narrow-band green electroluminescent materials, analyzing critical factors such as molecular engineering, excited-state characteristics, and device architecture to elucidate the relationship between molecular structure and the position, bandwidth, and emission properties of the emission peaks. By synthesizing these vital insights, this work aims to provide valuable theoretical foundations and practical guidance, helping researchers rationally and efficiently develop next-generation, high-performance green-emitting materials for advanced display and lighting applications.

The fundamental challenge in achieving high doping concentrations for multiple resonance emitters, while simultaneously suppressing Dexter energy transfer (DET)-induced concentration quenching, stems from their intrinsically long-lived exciton states. Moving beyond conventional steric hindrance strategies for intermolecular separation, we utilize terminal spirofluorene interactions to promote lamellar molecular stacking. This configuration enhances host-guest separation, achieving a Förster resonance energy transfer (FRET) radius of 3.19 nm, which effectively suppresses DET (with a DET rate constant: κDET = 3.48 × 105 s-1) while maintaining efficient FRET (with a FRET rate constant: κFRET = 1.59 × 108 s-1). This collective molecular orchestration breaks the concentration ceiling inherent to B/N-based systems without inducing spectral broadening (full-width-at-half-maximum, FWHM = 19/20 nm). As a proof of concept, our devices set new efficiency records for binary organic light-emitting diodes (OLEDs), reaching a peak external quantum efficiency (EQE) of 33.2% at 3%-5% doping in non-sensitized configurations and 36.9% with interlayer sensitization. This work introduces a materials design paradigm that successfully resolves the critical doping-concentration paradox in multiple resonance thermally activated delayed fluorescence (MR-TADF) systems, thereby enhancing their potential for commercial application.

Benzothienocarbazole (BTC) regioisomers, featuring a relatively heavy sulfur atom, a rigid molecular structure, and moderate electron-donating ability, are used in the design of TADF emitters. Here, a comprehensive structural and optoelectronic investigation of two narrowband blue MR-TADF emitters with rigid donor units is presented. A tert-butyldiphenylamine group at the para position of the boron atom gives these molecules a hybrid frontier molecular orbital distribution, showing both short-range charge transfer (SRCT) and long-range charge transfer (LRCT) traits. The rigid donor units not only diminish the high-frequency vibronic coupling strength of the commonly involved stretching modes but also lower the non-radiative decay rate constants of the triplet state. Consequently, these two emitters produce narrowband blue emissions with full width at half maximum (FWHM) values below 23 nm and high photoluminescence quantum yields over 90%. Non-sensitized OLEDs based on BTC-BN and BFC-BN exhibit blue emissions centered at 476 and 478 nm, with FWHMs of 31 and 29 nm, respectively, and maximum EQEs of 30.9% and 27.7%, respectively. This highlights the unique advantages and importance of the rigid donor in controlling the excited state and enhancing device performance.

We implemented a "terminal engineering" strategy to address the challenges of low efficiency and the difficulty of effectively narrowing the emission spectra within the single boron-nitrogen (BN) multi-resonance thermally activated delayed fluorescence (MR-TADF) emitter system. By adding flexible diphenylamino groups and insulating tert-butyl (t-Bu) groups, respectively, into the structurally simple CzBN and the polycyclic aromatic hydrocarbon (PAH)-based Indo-CzBN, two novel proof-of-concept MR-TADF emitters, DPA-CzBN and Indo-tCzBN, were successfully developed. Notably, the incorporation of t-butyl units into polycyclic aromatic hydrocarbon (PAH)-structured indolocarbazole derivatives not only markedly suppresses the vibration relaxation of the excited state, enabling Indo-tCzBN to achieve an exceptionally narrow full width at half maximum (FWHM) of 19 nm and a high photoluminescence quantum yield (PLQY) of up to 97.5%, but also significantly enhances the horizontal dipole orientation factor (Θ//) of Indo-tCzBN to 85.3%, compared to approximately 73.6% for Indo-CzBN. Accordingly, benefiting from the synergistic effect of a high Θ// factor and a high PLQY, both the non-sensitized and sensitized organic light-emitting diodes (OLEDs) based on Indo-tCzBN achieved maximum external quantum efficiencies (EQEmax) of 37.4% and 39.0%, respectively. These values rank among the highest reported for MR-TADF emitters constructed on a single BN molecular architecture.

Multiple-resonance thermally activated delayed fluorescence (MR-TADF) materials frequently exhibit extended exciton lifetimes, making device performance highly sensitive to minute variations in doping concentration. To mitigate this, we introduce two rigid, rod-like spiro-frameworks via non-conjugated single bonds into a traditional MR-TADF skeleton and intentionally design two MR-TADF emitters, designated as DspiroS-BN and TspiroS-BN. This external spiro modification strategy not only effectively suppressed the spectral broadening caused by long-range charge transfer (LRCT), thereby significantly improving spectral purity, with FWHM values of only ~21 nm in dilute toluene solution and 24 and 26 nm for DspiroS-BN and TspiroS-BN in doped films, respectively. Moreover, the enhanced molecular rigidity of the spiro structure and the possible moderate increase in the intermolecular interaction distance jointly led to a photoluminescence quantum yield (PLQY) of over 95% in the doped films. Notably, the optimized organic light-emitting diodes (OLEDs) achieve high external quantum efficiencies (EQEs) exceeding 34%, signifying a substantial performance improvement over the parent skeleton. Furthermore, the two materials exhibit excellent lysosome-targeting capabilities, and biological safety evaluations indicate that this series of probes demonstrates neither dark toxicity nor phototoxicity, thereby confirming their superior biocompatibility and promising potential for applications in bioimaging and long-term tracking. This work underscores the versatile properties of these two materials, offering a highly promising pathway for developing advanced multifunctional materials.

Residual invisible cracks make perfect material self-healing difficult to achieve. In principle, cracks could be visualized by luminescent indicators; however, high-energy fluctuations associated with rapid healing kinetics interfere with the electronic transitions of luminophores. Here, grouped secondary bonds are combined in a phenylborate-derived chain extender (BOB-1) in the structural form of supermolecule-analogous dimer, inhibiting conformation perturbation to enhance radiative transition. Asymmetric intramolecular O → B coordination affords a dynamic-exchange activation energy as low as 32.88 kJ·mol-1, enabling second-level healing at room-temperature and minute-level healing at 0 °C. Incorporated into polyurethane elastomers through a facile chain-extension procedure, this dynamic motif produces a distinguishable photoluminescent redshift upon O → B coordination, thereby localizing cracks. The material achieves near-100% mechanical recovery and retains at least 95% strength, over twice that of apparently flaw-free controls. Notably, only a 12.5 mol% BOB-1 fraction is required for chain-extending functionality, the engineering crack-visualization of self-healing integrity verification is expected.

Carbamates represent an important class of organic compounds with wide applications. Traditional methods for their synthesis often rely on the use of phosgene and its derivatives. Herein, a base‐promoted three‐component coupling reaction between aziridines, carbon dioxide (CO2), and amines has been successfully developed for the first time, providing an efficient route to a range of structurally diverse and valuable carbamates in high yields with excellent regioselectivities. The metal‐free reaction features mild reaction conditions, high functional group tolerance, and wide substrate scope.

The development of solution-processable and high-efficiency orange-red/red thermally activated delayed fluorescence (TADF) emitters remains a significant challenge. In this study, a series of novel hyper-structured molecules (HSMs) TADF orange-red emitters, P5A-NDMAC(x)-mCP(10-x) (x = 0, 1, 3, 5, 7, 9 or 10), featuring pillar[5]arene (P5A) core covalently bonded with NDMAC (red TADF unit) and mCP (host unit) via flexible alkyl linkage, were synthesized. These obtained HSMs exhibited remarkable thermal stability and good solubility. Spin-coating P5A-NDMAC(x)-mCP(10-x) (x = 0, 1, 3, 5, 7, 9 or 10) as the emitting layer, all the non-doped solutionprocessed organic light-emitting diodes (OLEDs) showed orange-red emission. Among them, the device based on P5A-NDMAC(1)-mCP(9) exhibited orange-red emission centered at 615 nm and the maximum external quantum efficiency (EQEmax) of 1.44%. Moreover, the doped device based on P5A-NDMAC(7)-mCP(3), using CBP as the host matrix, showed orange emission centered at 594 nm and EQEmax of 7.50%. These results indicate that P5A is a suitable core for constructing HSMs, providing an effective and feasible strategy for developing solutionprocessable TADF orange-red emitters.

Herein, we propose a synergistic regulation strategy that combines steric hindrance with the multiple resonance (MR) effect to design and synthesize a thermally activated delayed fluorescent (TADF) emitter, SF-PhDABNA. This is achieved by incorporating spirofluorene units and introducing meta -position phenyl linkages into the DABNA-1 core. As a result, SF-PhDABNA exhibits narrowband pure blue emission centered at 472 nm with a full width at half maximum (FWHM) of 23 nm. The unique steric hindrance structure of the material effectively suppresses pi- pi interaction, while maintaining a tightly ordered molecular arrangement through C-H & centerdot;& centerdot;& centerdot;pi and C-H & centerdot;& centerdot;& centerdot;B weak intermolecular interactions. This special packing pattern ensures a high photoluminescence quantum yield (PLQY) of 86 % in the doped film. Moreover, the significant directionality of the transition dipole moment (TDM) further enhances the light output coupling efficiency, thereby significantly improving the electroluminescence (EL) performance. The corresponding TADF-sensitized (TSF) OLED based on SF-PhDABNA achieves a maximum external quantum efficiency (EQEmax ) of 23.9 % with CIE coordinates of (0.121, 0.284). (c) 2026 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

A reductive tandem protocol that harnesses CO2 as a methylene source is reported, enabling direct and modular assembly of biologically relevant 3-aminomethyl chromones from simple o-hydroxyaryl enaminones and amines. The transformation proceeds under mild conditions with simple operation via hydrosilane-mediated four-electron reduction of CO2, generating reactive imine intermediates in situ for cascade cyclization. This strategy obviates pre-synthesized aminomethylating reagents, exhibits broad substrate tolerance, and provides step-economical access to diverse chromone scaffolds.

Here, we present a series of narrowband deep-blue EL emitters achieved by incorporating two functionally distinct boron (B) atoms into a molecular framework. We successfully obtained three proof-of-concept emitters, BOH-BN, BOH-CzBN, and CzBOH-BN, with excellent solubility in common solvents. One B atom forms a rigid cyclic structure with the ortho-nitrogen (N) and oxygen (O) atoms via three C-B bonds, creating a structural unit with notable multiple-resonance (MR) properties, whose primary function is to narrow the molecular emission peak. The other B atom interacts with neighboring hydroxyl (OH) and N atoms to form a six-membered ring structure that lacks MR features but increases monomolecular rigidity, preventing long-range conjugation, which helps maintain the material's emission in the deep blue region and effectively suppresses non-radiative decay. BOH-BN, BOH-CzBN, and CzBOH-BN all exhibited very narrow, deep-blue emission with photoluminescence (PL) peaks at 444 nm, 441 nm, and 458 nm, respectively, and FWHM values of 20 nm, 17 nm, and 19 nm. Notably, the CIE color coordinates of BOH-BN (0.145, 0.038) and BOH-CzBN (0.150, 0.036) are very close to the BT.2020 standard indicating high color purity and a good match with UHD display color gamuts. The corresponding deep-blue OLEDs based on BOH-BN, BOH-CzBN, and CzBOH-BN exhibit peak external quantum efficiencies (EQEs) exceeding 5%, indicating that this series of materials has the potential to achieve high-performance EL properties via solution processing.

ABSTRACT Integrating circularly polarized electroluminescence (CPEL) into light‐emitting diodes (LEDs) is crucial for advanced optical applications. However, its application is impeded by a longstanding trilemma involving a sufficient electroluminescence asymmetry factor (g EL ), high external quantum efficiency (EQE), and narrow emission bandwidth. Here, a new strategy is proposed for generating CPEL in both circularly polarized organic light‐emitting diodes (CP‐OLEDs) and circularly polarized LEDs (CP‐LEDs) by incorporating a chiral additive into the PEDOT:PSS ((3, 4‐ethylenedioxythiophene):poly(styrene sulfonate)) hole‐injection layer (HIL) to induce a spin‐flipping. Consequently, solution‐processable CP‐OLEDs based on common achiral emitters achieve advantages of high g EL , high EQE, and excellent color purity. Comparing the original PEDOT:PSS based devices, improved maximum external quantum efficiency (EQE max ) of 17.2%, 20.3%, 12.0%, and 23.0% were obtained, with |g EL | of 2 × 10 −2 , 6 × 10 −3 , 1 × 10 −2 , and 1 × 10 −3 , for blue multi‐resonance emitter, green phosphorescent emitter, and green multi‐resonance emitters, respectively. This strategy enables deep‐red perovskite‐based CP‐LEDs to deliver not only pronounced CPEL but also several‐fold enhancements in performance. Angle‐dependent CPEL measurements confirm the observed CPEL originating from spin‐flip induction rather than polarization effects. This chiral additive HIL strategy establishes a universal platform for efficient CPEL across a wide range of achiral emitters and is applicable to both OLED and LED technologies.

To meet the critical demand for ultra-high-definition (UHD) display technology, luminescent materials must achieve precise peak emission positions and narrow emission bandwidths simultaneously. Herein, we report a new class of narrowband pure green thermally activated delayed fluorescence (TADF) materials, DBNDO-1, DBNDO-2, and DBNDO-3. These compounds are constructed on diborane-embedded polycyclic aromatic hydrocarbon (PAH) skeletons fused with a dibenzo[b,d]furan motif. Through strategic incorporation of three distinct terminal substituents, 3,4,5-trifluorophenyl, 4-(trifluoromethyl)phenyl, and 3,5-bis(trifluoromethyl)phenyl units, we further precisely modulate emission maxima while maintaining narrowband emission characteristics. All of these emitters exhibit bright green luminescence and narrowband emission characteristics, with luminescence peaks ranging from 513 to 518 nm. The full width at half maximum (FWHM) is only 14 to 16 nm in dilute toluene solution. Additionally, the photoluminescence quantum yields (PLQYs) for all of these emitters exceed 95%. The corresponding optimized OLEDs based on DBNDO-1, DBNDO-2, and DBNDO-3 achieved peak external quantum efficiencies (EQEmax) of 33.7%, 32.4%, and 32.0%, respectively. The CIEy coordinates for these OLEDs were 0.74, 0.75, and 0.75, with FWHM values ranging from 18.5 to 19.4 nm. To the best of my knowledge, the EQEs, FWHM, and CIEy values represent some of the most exceptional performance metrics reported in the current literature.

Electrocatalytic nitrate reduction reaction (NITRR) represents a promising approach for ammonia synthesis, but existing application has been constrained by the complex proton-coupled electron transfer and the sluggish kinetics induced by various intermediates. Herein, we synthesized a series of metalized covalent organic frameworks: NiTP-MTAPP MCOFs (M = 2H, Co, Cu, and Fe), based on dual redox-active centers: thiophene-substituted Ni-bis(dithiolene) ligand-Ni[C 2 S 2 (C 4 H 2 SCHO) 2 ] 2 and metallic porphyrin. Through regulating the adsorption and desorption of species at the catalytic sites, we have identified the optimal NITRR electrocatalyst: NiTP-CoTAPP MCOF, which achieved the highest faradaic efficiency (FE) of approximately 85.6% at −0.8 V (vs. RHE) in pure nitrate solution, with an impressive yield rate of 160.2 mmol h −1 g −1 cat. The generation of active hydrogen at [NiS 4 ] sites achieved dynamic equilibrium with the timely hydrogenation reaction at CoN 4 sites, effectively suppressing the hydrogen evolution reaction. Moreover, the incorporation of thiophene (TP) groups and metal ions facilitates charge transfer. Density functional theory (DFT) calculations demonstrated the reduction in energy barriers at different catalytic sites. The CoN 4 −NiS 4 system exhibited the optimal adsorption-to-desorption capability and the lowest energy barrier (0.58 eV) for the rate-determining step (*NO → *HNO), which is supported by the moderate d-band center and Bader charge value.

Oleanolic acid (OA), a natural product with diverse biological activities, faces clinical limitations due to its poor bioavailability caused by hydrophobic pentacyclic structure. To address this issue, we designed a novel class of oleanolic acid–short peptide derivatives (OA‐GFFK) by conjugating OA with a water‐soluble short peptide (glycine‐phenylalanine‐phenylalanine‐lysine, GFFK). Molecular dynamics simulation (MD) and density functional theory (DFT) predicted its gelation properties, and OA‐GFFK was successfully transformed into supramolecular hydrogels via a simple three‐step process (dissolution‐ultrasonication‐resting). Structural characterization revealed that gelation is driven by π–π stacking and hydrogen bonding, leading to a nanofiber network. And the hydrogels exhibited excellent self‐healing, shear response, biocompatibility, and antibacterial activity. This study details a research process for the design and simple preparation of oleanolic acid‐short peptide derivative hydrogels, providing design insights and a theoretical basis for developing OA derivatives.

Herein, a parallel "bifunctional group" modulation method is proposed to achieve controlled modulation of the emission wavelength and full-width at half-maximum (FWHM) values. As a result, three proof-of-concept emitters, namely DBNDS-TPh, DBNDS-DFPh, and DBNDS-CNPh, are designed and synthesized, with the first functional dibenzo[b,d]thiophene unit concurrently reducing the bandgap and elevate their triplet state energy. A second functional group 1,1':3',1″-triphenyl, and electron acceptors 1,3-difluorobenzene and benzonitrile, respectively, to deepen the HOMO and LUMO levels. Accordingly, the CIE coordinates of DBNDS-TPh, DBNDS-DFPh, and DBNDS-CNPh are (0.13, 0.77), (0.14, 0.77), and (0.14, 0.76) respectively, in a dilute toluene solution. This marks the first instance of achieving a CIEy value of 0.77 in dilute toluene solutions. Significantly, the non-sensitized pure-green OLEDs based on DBNDS-TPh and DBNDS-DFPh demonstrate peak EQE of 35.0% and 34.5%, with corresponding CIE coordinates of (0.18, 0.75), (0.17, 0.76) at the doping concentration of 1 wt.%, representing the first green OLED with a CIEy value reaching 0.76 in a bottom-emitting device structure as reported in the literature.

Polyurethane with a dynamic cross-linking network provides promising next-generation solid propellant binders due to its self-healing and recyclability for improved safety and durability. However, dynamic cross-linking networks with self-healing usually lead to insufficient mechanical properties due to the contradiction between their constitutive relation and molecular chain mobility. Here, a strategy of dynamic bicontinuous structure was proposed to regulate molecular chain motion for integrated good moderate-temperature self-healing, mechanical strength, toughness, and recyclability. The acylsemicarbazide group was introduced into the polyurethane molecular chain for the formation of a stable cross-linking network and intermolecular sextuple hydrogen bonds. An asymmetric structure was designed to convert the typical island-phase morphology into a unique bicontinuous phase. The optimized chain mobility was regulated by a noncovalent reversible network of hydrogen bonds coupled with an asymmetric structure-induced bicontinuous microstructure. The obtained polyurethane exhibited an excellent mechanical strength of 51 MPa, 1410% elongation at break, a toughness of 260 MJm-3, and a fracture energy of 120.24 kJm-2. An impressive moderate-temperature self-healing of 90% was achieved within 12 h. Such a strategy provides insights for the development of high-performance binders or other high-fill energetic materials.

Synthetic methodology is a fundamental framework for preparing functional materials, significantly advancing their development. Herein, a novel 6π electrocyclization reaction is unexpectedly discovered that promotes further ring closure in materials derived from multi-resonance thermally activated delayed fluorescence (MR-TADF) compounds, known for their narrow emission. By simply raising the reaction temperature, this process significantly red-shifts the emission peak of the target material while effectively narrowing its emissive width and greatly enhancing its optoelectronic performance. Utilizing this method, the newly synthesized MR-TADF substrate material GCz-4B2 is successfully converted into the target compound GCz-4B1. Compared to GCz-4B2, the emission peak of GCz-4B1 exhibited a redshift of 26 nm while concurrently achieving a significant reduction in its full width at half-maximum (FWHM) value and corresponding shoulder intensity. Notably, the photoluminescence quantum yield (PLQY) of GCz-4B1 reached 95.1%, compared to only 85.6% for GCz-4B2. This enhancement can be attributed to the increased rigidity from the further ring closure reaction, which reduced unfavorable vibrational relaxation processes and improved PLQY values. Furthermore, OLEDs based on GCz-4B1 attained a maximum external quantum efficiency (EQEmax) of 28.0%, with a small FWHM value of 19.4 nm, significantly surpassing that of devices derived from GCz-4B2.