Heating induced aggregation in non-fullerene organic solar cells towards high performance

Molecular ordering within the photoactive layer plays a crucial role in determining the device performance of organic solar cells(OSCs).However,the simultaneous molecular ordering processes of polymer donors and non-fullerene acceptors(NFAs)during solution casting usually bring confinement effect,leading to insufficient structural order of photovoltaic components.Herein,the molecular packing of mINPOIC NFA is effectively formed through a heating induced aggregation strategy,with the aggregation of PBDB-T,which has a strong temperature dependence,is retarded by casting on a preheated substrate to reduce its interference toward m-INPOIC.A sequent thermal annealing treatment is then applied to promote the ordering of PBDB-T and achieve balanced aggregation of both donors and acceptors,resulting in the achievement of a maximum efficiency of 13.9% of PBDB-T:m-INPOIC binary OSCs.This work disentangles the interactions of donor polymer and NFA during the solution casting process and develops a rational strategy to enhance the molecular packing of NFAs to boost device performance.

Comparative studies on molecular induced aggregation of hepta-imidazoliumyl-β-cyclodextrin towards anionic surfactants

A β cyclodextrin derivative bearing seven cationic arms and its singly charged analogue, i.e., per-6- deoxy-f-（1-methylimidazol-3-ium-3-yl）-β-cyclodextrin （3） and mono-fi-deoxy-6-（1-methylimidazol- 3-ium-3-yl）-β-cyclodextrin （4） were synthesized and fully characterized. Their induced aggregation behaviours towards two anionic surfactant, that is, sodium dodecyl sulfonate （SDS） and dioctyl sodium sulfosuccinate （Aerosol OT, AOT）, were investigated by UV-vis, NMR, Zeta-potential, dynamic light scattering （DLS）, and transmission electron microscopy. The results revealed that host 3 can induce the molecular aggregation of anionic surfactant at concentration far lower than its original CAC, leading to the larger diameter, the narrower size distribution and the higher thermal stability of the induced aggregate towards the anionic surfactant possessing more hydrophobic tails.

Aggregation Operators for Decision Making Based on q-Rung Orthopair Fuzzy Hypersoft Sets:An Application in Real Estate Project

In this paper,a decision-making problem with a q-rung orthopair fuzzy hypersoft environment is developed,and two operators of ordered weighted average and induced ordered weighted average are developed.Several fundamental features are also derived.The induced ordered weighted average operator is essential in a q-ROFH environment as the induced ordered aggregation operators are special cases of the existing aggregation operators that already exist in q-ROFH environments.The main function of these operators is to help decision-makers gain a complete understanding of uncertain facts.The proposed aggregation operator is applied to a decision-making problem,with the aim of selecting the most promising real estate project for investment.

A ggregation-induced emission nanoparticles for in vivo three-photon fuorescence microscopic rat brain angiography

Rodents are popular biological models for physiological and behavioral research in neuroscience and rats are better models than mice due to their higher genome similarity to human and more accessible surgical procedures.However,rat brain is larger than mice brain and it needs powerful imaging tools to implement better penetration against the scattering of the thicker brain tissue.Three-photon fluorescence microscopy(3PFM)combined with near-infrared(NIR)excitation has great potentials for brain circuits imaging beause of its abilities of anti scattering,deep-tissue imaging,and high signal-to-noise ratio(SNR).In this work,a type of AIE lumninogen with red fuorescence was synthesized and encapsulated with Pluronic F-127 to make up form nano-particles(NPs).Bright DCDPP-2TPA NPs were employed for in trino three-photon fuorescent laser scanning microscopy of blood vessels in rats brain under 1550 nm femtosecond laser exci-tation.A fine three-dimensional(3D)reconstruction up to the deepness of 600 pm was achieved and the blood flow velocity of a selected vessel was measured in vrito as well.Our 3PFM deep brain imaging method simultaneously recorded the morphology and function of the brain blood vessels in vivo in the rat model.Using this angiography combined with the arsenal of rodent's brain disease,models can accelerate the neuroscience research and clinical diagnosis of brain disease in the future.

Recent advances in biomimetic aggregation-induced emission photosensitizers for photodynamic therapy and immunotherapy

The development of novel photosensitizers(PSs)with aggregation-induced emission(AIE)properties has emerged as a crucial advancement in the field of photodynamic therapy(PDT).However,the versatile applications of AIE PSs are limited by low encapsulation efficiency and inadequate target tissue permeability.Biomimetic technology stands out as a promising strategy to overcome these challenges,aiming to enhance AIE PSs tumor penetration efficacy,and their association with antitumor immune responses.In this review,recent advancements in biomimetic AIE PSs for PDT and immunotherapy are summarized.We start with introducing strategies involving biomimetic AIE PSs based on cell membranes and extracellular vesicles for the combined application of PDT and immunotherapy.We then discuss the preparation of biomimetic AIE PSs nanoparticles.Finally,we briefly outline the challenges and prospects associated with biomimetic AIE PSs.

Design of activatable red-emissive assay for cysteine detection in aqueous medium with aggregation induced emission characteristics

A novel wate r-soluble red-emissive AIE fluorescence probe for cysteine(Cys) in situ was prepared and the performance of selectivity and sensitivity has been carefully investigated in this study.The probe was established on the electrostatic interaction of sulfonate functionalized tetraphenylethene(TPE) and polycation generated by the reaction between a polymer bearing dinitrobenzenesulfonate groups and Cys.From the experimental results,it was easy to distinguish Cys from glutathione(GSH) and homocysteine(Hcy) with a detection limit of 73 nmol/L.The assay system also possessed strong antiinterference ability against multitudinous amino acids.The Stokes shift was 142 nm and the emission ranged from 550 nm to 850 nm.In addition,double responses in fluorescence and ultraviolet-visible spectra also make the red-emissive assay ideal for sensitive detection and quantification of Cys for most purposes,especially in-situ monitoring of Cys in aqueous medium.

Polythiophene Derivatives Carbonized Polymer Dots:Aggregation Induced Solid-State Fluorescence Emission

Comprehensive Summary Currently,solid-state fluorescent carbonized polymer dots(CPDs)have attracted attention increasingly due to their applications for optoelectronic display.However,designing CPDs possessing solid-state fluorescence and clarifying the fluorescence mechanism remain challenging.Herein,we initially synthesized a novel type of polythiophene derivatives CPDs,poly-4,4’-(thiophene-3,4-diyl)dibenzoic acid carbonized polymer dots(PDBA-CPDs)with solid-state fluorescence.Subsequently,the structural and optical characterization revealed that the solid-state fluorescence originated from the aggregation induced emission of the CPDs.In brief,in aggregation state,the remaining polymer structure groups on the surface of the CPDs overlapped and weakened the non-radiative transition,enhancing solid-state fluorescence emission.Thirdly,three polythiophene-derived CPDs were designed to further demonstrate the aggregation induced solid-state fluorescence mechanism.Finally,owing to their unique properties of solid-state fluorescence,the white LEDs(light emitting diodes)were fabricated with high color rendering index(CRI)of 82.7 and CIE coordinates of(0.37,0.39)using commercial 460 nm chip.

Naphthalene diimide based near-infrared luminogens with aggregation-induced emission characteristics for biological imaging and high mobility ambipolar transistors

Organic conjugated materials combining high conductivity with strong solid-state emission are highly desired for organic electronic applications,yet still rather rare.Herein,a novel luminogen(TEN)comprised by linking naphthalene diimides and triphenyl ethylene with vinyl bridges is reported.TEN exhibits aggregation-induced emission(AIE)behavior of a strong nearinfrared fluorescence over 700 nm and the efficiency above 60.5%in the solid state,while also shows promising application in vivo bio-imaging with good permeability and extremely low background.Single crystal of TEN reveals intra-and intermolecular C–H…O hydrogen bonds,contributing to an inclined molecular stacking along the a-axis of the cell,creating a 1 D charge carrier transporting channel under a shortπ-πinteraction distance of 3.42?,which might benefit the solid emission and charge transport ability simultaneously.Solution processed bottom contact,top gate organic field effect transistors based on TEN reveal a high ambipolar charge transport ability with the hole mobility up to 0.13 cm2 V-1 s-1 and electron mobility up to0.010 cm2 V-1 s-1.Further atomic force microscopy and X-ray diffraction analysis on TEN thin film confirm the existence of the1 Dπ-πstacking channel,suggesting the stacking geometry revealed in crystal crucial for facilitating high charge carrier mobility while preserving the strong solid emission at the same time.

Blue-green Phosporescent Iridium Complex with Terdentate Ligand

An ionic iridium（Ⅲ） complex[Ir（F2dpyb）（bzdpp）2Cl][OTf]with 1,3-difluoro-4,6-di（2-pyridinyl） benzene（F2dpybH） terdentate ligand and benzyldiphenylphosphine（bzdpp）ligand was synthesized and characterized.The structure of iridium complex was verified by single-crystal X-ray crystallography.It crystallizes in monoclinic,space group P21/n with a =14.3654（7）,b = 23.0026（10）,c = 15.7964（7） A°,β = 97.6029（11）,V= 5173.9（4） A°3,Z = 4,F（000） =2552,Dc = 1.645 Mg/m^3,Mr = 1281.49 and μ = 0.071 mm^-1.The UV-vis absorption and phosphorescence of the complex were discussed.The complex was ＇aggregation induced emission（AIE）＇ active.It exhibited no emission in CH2Cl2 solution but strong blue-green emission in solid state under ultraviolet light excitation.The complex emitted a strong phosphorescence centered at493 nm when doped in PMMA.Its lifetime is 0.755 μs and quantum yield is approximately 0.134.

Recent advances in stimuli-responsive theranostic systems with aggregation-induced emission characteristics

Theranostic systems by integrating the tumor imaging and tumor therapeutic capabilities into one platform have attracted numerous attentions from worldwide researchers.Despite the great developments,their clinical application is still in the nascent stage,owing to the unsatisfied imaging quality and limited therapeutic efficacy.Fortunately,the emerging of aggregation-induced emission(AIE)molecules with unique fluorescence property offers an opportunity to solve the imaging problem.Besides,further utilizing the tumor microenvironments and external triggers to design the stimuli-responsive imaging-guided therapy could enhance the therapeutic efficacy and reduce the side effects.In this review,the advancements in stimuli-responsive theranostic systems with AIE characteristics are summarized.Theranostic systems are first classified according to their treatment modes,and then subdivided based on various stimuli,including pH,redox,enzyme,and light.In each section,the design strategies and application examples are introduced.At last,the current state of the art,limitations,as well as prospects are also discussed.

Host molecule enhanced aggregation induced emission of chiral silver nanoclusters for achieving highly efficient circularly polarized electroluminescence

Chiral metal nanoclusters(MNCs)are competitive candidates for fabricating circularly polarized light-emitting diodes(CPLEDs),but the device performance is greatly limited by the poor emission of MNCs in solid thin films.Herein,host molecule enhanced aggregation induced emission(AIE)of MNCs is demonstrated for fabricating highly efficient CPLEDs.Namely,on the basis of the AIE effect of atomically precise enantiomeric(R/S)-4-phenylthiazolidine-2-thione capped silver(R/S-Ag_(6)(PTLT)_(6))NCs in solid thin films,1,3-bis(carbazol-9-yl)benzene(mCP)is introduced as a host molecule to control the orientation and packing arrangements of R/S-Ag_(6)(PTLT)_(6) NCs throughπ–πinteractions with the R/S-Ag_(6)(PTLT)_(6) NCs and further enhance the AIE.The as-fabricated Ag_(6)(PTLT)_(6) NC/mCP hybrid solid thin film shows a high photoluminescence quantum yield of 71.0%close to that of Ag_(6)(PTLT)_(6) NC single crystal.As the hybrid films are employed as the active emission layers of CPLEDs,mCP also suppresses the triplettriplet annihilation and balances the charge transport.Thus,the CPLEDs exhibit a maximum brightness of 3,906 cd/m^(2),peak external quantum efficiency of 10.0%,electroluminescence dissymmetry factors of−5.3×10^(−3)and 4.7×10^(−3).

Piezochromic luminescence and aggregation induced emission of 9,10-bis[2-(2-alkoxynaphthalen-1-yl)vinyl]anthracene derivatives

Four derivatives of 9,10-bis[2-（2-alkoxynaphthalen-1-yl）vinyl]anthracene（BNAs） were designed,successfully synthesized and characterized by spectrofluorometer, powder wide-angle X-ray diffraction（PXRD） and differential scanning calorimetry experiments（DSC）, etc. It was found that these compounds exhibited aggregation-induced emission phenomenon. Moreover, these target compounds displayed reversible color change from yellow to orange upon pressing and annealing process. Interestingly, all of BNAs obviously presented red-shifted piezofluorochromic（PFC） properties and behaved mainly length dependence of alkoxy group, in which, BNA displayed the largest PFC spectral shift（DlPFC= 26 nm）. The PXRD profiles demonstrated the transformation from crystalline to amorphous state upon grinding, and the mechanism of PFC behaviors was proposed. Thus, changing the length of alkoxyl chain could be an alternative way to tune their PFC behaviors.

Luminescent properties of thermally activated delayed fluorescence molecule with intramolecular π-π interaction between donor and acceptor

Influence of intramolecular π-π interaction on the luminescent properties of thermally activated delayed fluorescence（TADF） molecule（3, 5-bis（3,6-di-tert-butyl-9 H-carbazol-9-yl）-phenyl）（pyridin-4-yl） methanone（DTCBPY） is theoretically studied by using the density functional theory（DFT） and time-dependent density functional theory（TD-DFT）.Four conformations（named as A, B, C, and D） of the DTCBPY can be found by relax scanning, and the configuration C corresponds to the luminescent molecule detected experimentally. Besides, we calculate the proportion of each conformation by Boltzmann distribution, high configuration ratios（44% and 52%） can be found for C and D. Moreover, C and D are found to exist with an intramolecular π-π interaction between one donor and the acceptor; the intramolecular interaction brings a smaller Huang-Rhys factor and reduced reorganization energy. Our work presents a rational explanation for the experimental results and demonstrates the importance of the intramolecular π-π interaction to the photophysical properties of TADF molecules.

Circularly polarized luminescence induced by excimer based on pyrene-modified binaphthol

A new chiral bromobinaphthol-pyrene compound was developed to achieve a green circularly polarized luminescence(CPL)from its excimer with a dissymmetry factor(|glum|)value of 4.3×10^-3 and a high quantum yieldΦF,solid up to 55.9%,while no CPL signals could be observed for the blue luminescence from unimolecule.Meanwhile,reversal CPL signals can be observed from both concentrated solution and solid.

Mitochondria-targeted nano-AIEgens as a powerful inducer for evoking immunogenic cell death

AIEgens can serve as an effective platform for the construction of photosensitizer-based immunogenic cell death(ICD)inducers.To date,several mitochondria or endoplasmic reticulum(ER)-targeted aggregationinduced emission(AIE)molecules have been developed and have evoked massive ICD in cells.However,due to the complex physicochemical environment in cells,these small AIE molecules cannot maintain a stable aggregate state,which not only affects the fluorescence intensity of the photosensitizer but also decreases the generation of reactive oxygen species(ROS),and thus reducing the effect of the photosensitizer to elicit ICD.AIEgen-based nanomicelles,which maintain a stable micellar structure,can prevent defects of AIE molecules in photodynamic therapy(PDT)applications.Therefore,in this study,a mitochondria-targeted AIE nanophotosensitizer was synthesized and used as a highly potent ICD inducer for vaccine preparation and tumor prevention.

Lighted up by hydrogen-bonding: luminescence behavior and applications of AIEgen-doped interpenetrating network hydrogel

The interaction between the aggregation-induced emissive(AIE) luminogens(AIEgen) and the polymer is the key scientific question in the design of functional AIE hydrogels. In this study, we report the AIE behavior of a poly(acrylic acid)(PAAc) and poly(acrylamide)(PAAm) interpenetrating network(IPN) hydrogel doped with tetra-cationic tetraphenylethene(TCTPE). The cationic AIEgen can bind with PAAc through ionic interaction, while PAAc and PAAm chains can associate with each other through hydrogen-bonds(H-bonds). These two interactions can restrict the intramolecular rotation and thus activate the luminescence of the AIEgen. The PAAc-PAAm H-bonds can be broken by increasing temperature or p H, restoring the intramolecular rotation of the AIEgen and quenching the fluorescence of the hydrogel. Therefore, the TCTPE-doped IPN hydrogel is designed as temperature-and p H-sensitive displayers which can record information imprinted by photo-printing or iono-printing with good switchability and reversibility. Another application of this TCTPE-doped hydrogel is demonstrated as a luminescent soft actuator, which has fast shape deformation and editable fluorescence pattern. The above results reveal a pathway to tune the emission behavior through tuning polymer-polymer and polymer-AIEgen interactions, which may inspire new design strategies of aggregation-induced emissive polymers and broaden their applications.

Synthesis and electronic properties of expanded 5-(hetero)arylthien-2-yl substituted 3-ethynyl quinoxalines with AIE characteristics

Expanded 5-(hetero)aryl-thien-2-yl substituted 3-ethynyl quinoxaline dyes with variable substitution pattern on the peripheral thiophene ring were synthesized in moderate to very good yields by Suzuki and Buchwald-Hartwig coupling of the corresponding brominated 3-ethynyl quinoxalines. Dumbbell-shaped bis(thienyl 3-ethynyl quinoxalines) are also accessible by the Suzuki protocol. The photophysical properties were investigated by UV and fluorescence spectroscopy. Most of the obtained compounds display fluorescence in solution and some of them also in the solid state. Additionally, tuning of the emission color of the quinoxaline based chromophores can be conveniently accomplished by the remote substituent group. The determined absorption and emission maximum as well as the Stokes shifts strongly correlate with Hammett σp+parameters. Besides,photophysical properties of selected derivatives in the solid state, biphasic solutions, and PMMA films, along with their relationships, are comparatively investigated. Moreover, two 5-(hetero)aryl-thien-2-yl substituted 3-ethynyl quinoxaline dyes are aggregation induced emission(AIE) chromophores indicated by restriction of molecular motions. A covalently restricted 3-ethynyl quinoxaline supports that the inhibition of molecular rotation is responsible for the significant enhancement of fluorescence in acetonitrile/water mixtures.

Multifunctional aggregates for precise cellular analysis

Precisely analyzing the target materials in living cells can reveal the essence and mystery of life at a deeper level,which will provide reliable theoretical basis for the occurrence,development,treatment and prognosis of major diseases.However,because living cells are in the dynamic process of metabolism,there are several challenges existed in accurate analysis,including subcellular compartment heterogeneity,plasma membrane interface barrier,and cell cycle regulation.In this regard,our group has designed and synthesized a series of multifunctional aggregates by mainly integrating the peptide elements,nucleic acid elements and aggregation elements to overcome the barriers.This article summarizes the latest developments of multifunctional aggregates for precise cell analysis by our group,and systematically introduces them according to different design concepts and targeting dimensions,such as space,efficiency as well as time.We hope this work could contribute to analyzing the biomarkers in cells through constructing the multifunctional aggregates,understanding the operation mechanism of cells,finally inspiring technology breakthroughs in biomedical fields.

Synthesis and characterization of fluorescence active G_(4)-quartet and direct evaluation of self-assembly impact on emission

Fluorescence(FL)active 8-aryl guanosine derivatives were prepared and applied for cation mediated self-assembly to form the H-bonded G_(8)-quadruplexes.The p-cyano(p-CN)and 8-anthracene(8-An)substituted guanosines were identified to give the strongest fluorescence with the formation of G_(8)-octamers(G_(8))both in solution(NMR)and solid state(X-ray).This well-defined G_(8)-octamer system has provided the first direct evidence on the self-assembled G-quadruplex fluorescence emission with aggregation-induced emission(AIE),which could be applied as the foundation for FL molecular probe design toward G-quadruplex recognition.

A cationic amphiphilic tetraphenylethylene derivative with hydrochromic sensitive property:Applications in anti-counterfeiting ink and rewritable paper

Since the discovery of aggregation induced emission(AIE)phenomenon,various stimuli-responsive materials have been rapidly developed,but there are still great challenges in the application of ink printing due to the bad water solubility.In this research,a new cationic amphiphilic TPE-functionalized pyridine salt(TPE-OTs)was designed,which shows good water solubility and hydrochromic properties.The optical properties of the compound have been studied,which is equipped with the typical AIEE characteristics and TICT effect.The compound can self-assemble to form aggregates with a particle size of about 30 nm in water.What is more,the compound is responsive to the environmental humidity,whose fluorescent color changes from green to yellow as the humidity gradually increased.Based on this characteristic,we applied it to the fluorescent anti-counterfeiting ink,realizing the protection and encryption of information.