Phenylfluorenamine-functionalized poly(N-vinylcarbazole)s as dopant-free polymer hole-transporting materials for inverted quasi-2D perovskite solar cells

In order to improve the efficiency and stability of inverted three-dimensional(3D) or quasi-2D perovskite solar cells(PSCs) for future commercialization, exploring high efficient dopant-free polymer holetransporting materials(HTMs) is still desired and meaningful. One simple and efficient way to achieve high performance dopant-free HTMs is to synthesize novel non-conjugated side-chain polymers via rational molecular design. In this work, N-(4-methoxyphenyl)-9,9-dimethyl-9H-fluoren-2-amine(FMeNPh) groups are introduced into the poly(N-vinylcarbazole)(PVK) side chains to afford two nonconjugated polymers PVCz-DFMeNPh and PVCz-FMeNPh as dopant-free HTMs in inverted quasi-2D PSCs. Benefited from the flexible properties of polyethylene backbone and excellent optoelectronic natures of FMeNPh side-chain groups, PVCz-DFMeNPh with more FMeNPh units exhibited excellent thermal stability, well-matched energy levels and improved charge mobility as compared to PTAA and PVCzFMeNPh. Moreover, the morphologies investigation of quasi-2D perovskite on PVCz-DFMeNPh shows more compact and homogeneous perovskite films than those on PTAA and PVCz-FMeNPh. As a result,the dopant-free PVCz-DFMeNPh based inverted quasi-2D PSCs deliver power conversion efficiency(PCE) up to 18.44% as well as negligible hysteresis and favorable long-term stability, which represents as excellent performance reported to date for inverted quasi-2D PSCs. The results demonstrate the great potentials of constructing non-conjugated side-chain polymer HTMs based on phenylfluorenamine-func tionalized PVK for the development of high efficient and stable inverted 3D or quasi-2D PSCs.

Construction of ultra-stable NiFe armored catalyst for liquid and flexible quasi-solid-state rechargeable Zn-air batteries

The commercial application of non-precious metal-based electrocatalysts is not only limited by the intrinsic activity of the catalysts,but also the stability of the catalysts is extremely important.Herein,we fabricated an ultra-stable NiFe armored catalyst(Ar-NiFe/NC)by a simple secondary pyrolysis strategy.The as-obtained Ar-NiFe/NC electrocatalyst exhibits an excellent bifunctional oxygen electrocatalytic performance with an activity indicatorΔE of 0.74 V vs.reversible hydrogen electrode(RHE).More importantly,the Ar-NiFe/NC electrocatalyst also shows a remarkable operational and storage stability.After accelerated durability test(ADT)cycles,no obvious degradation of oxygen electrocatalytic performance could be observed.In addition,the Ar-NiFe/NC electrocatalyst still exhibits an unbated oxygen electrocatalytic performance comparable to fresh catalysts after three months of air-exposed storage.The assembled liquid and flexible quasi-solid-state rechargeable Zn-air batteries with the Ar-NiFe/NC electrocatalyst exhibit impressive performance.The liquid rechargeable Zn-air batteries possess a high open-circuit voltage(OCV)of 1.43 V and a salient peak power density of 146.40 mW·cm^(−2),while the flexible quasi-solid-state rechargeable Zn-air batteries also exhibit an excellent OCV of 1.60 V and an exciting peak power density of 41.99 mW·cm^(−2).

Modification of polyfluorene nanoparticles via inclusion complexa- tion based on cyclodextrin for lectin sensing and cell imaging

Currently, conjugated polymer nanoparticles are widely used with many biological applications, especially bio-imaging and labeling. Thus their modification with different biomacromolecules becomes a crucial step before various applications. In literature,this modification was normally performed via covalent bonds. To our best knowledge, modification based on inclusion complexation has not been reported. Herein, via host-guest interaction between cyclodextrin and adamantane, supramolecular modification to conjugated polyfluorene nanoparticles has been successfully achieved. The glycopolymer-modified conjugated polymer nanoparticles showed excellent binding ability to lectins, such as Galectin-3 and selective imaging behavior to Hep G2 cells.

Electrospun Supramolecular Hybrid Microfibers from Conjugated Polymers:Color Transformation and Conductivity Evolution

A type of novel electrospun supramolecular hybrid microfibers comprising poly(9-(4-(octyloxy)-phenyl)-2,7-fluoren-9-ol)(PPFOH)and poly(A/-vinylcarbazole)(PVK)are successfully prepared for intriguing multi-color emission properties.The supramolecular tunable PPFOH aggregation in PVK matrix endows the complex with a smart energy transfer behavior to obtain the multi-color emissions.In stark contrast to PVK fibers,the emission color of PPFOH/PVK fibers with an efficient dispersion of PPFOH fluorophores at a proper dope ratio can be tuned in a wide spectrum of blue(0.1%),sky blue(0.5%),nearly white(1%),cyan(2%),green(5%)and yellow(10%).Besides,conductive behaviors of the microfiber were demonstrated in accompany with the increment of the doping ratio of PPFOH to PVK.Successful fabrication of polymer light-emitting diode(PLED)based on the blended electrospun fiber provided a further evidence of its excellent electrical property for potential applications in optoelectronic devices.

Unveiling the Effects of Interchain Hydrogen Bonds on Solution Gelation and Mechanical Properties of Diarylfluorene-Based Semiconductor Polymers

The intrinsically rigid and limited strain of most conjugated polymers has encouraged us to optimize the extensible properties of conjugated polymers.Herein,learning from the hydrogen bonds in glucose,which were facilitated to the toughness enhancement of cellulose,we introduced interchain hydrogen bonds to polydiarylfluorene by amide-containing side chains.Through tuning the copolymerization ratio,we systematically investigated their influence on the hierarchical condensed structures,rheology behavior,tensile performances,and optoelectronic properties of conjugated polymers.Compared to the reference copolymers with a low ratio of amide units,copolymers with 30%and 40%amide units present a feature of the shearthinning process that resembled the non-Newtonian fluid,which was enabled by the interchain dynamic hydrogen bonds.Besides,we developed a practical and universal method for measuring the intrinsic mechanical properties of conjugated polymers.We demonstrated the significant impact of hydrogen bonds in solution gelation,material crystallization,and thin film stretchability.Impressively,the breaking elongation for P4 was even up to~30%,which confirmed the partially enhanced film ductility and toughness due to the increased amide groups.Furthermore,polymer light-emitting devices(PLEDs)based on these copolymers presented comparable performances and stable electroluminescence(EL).Thin films of these copolymers also exhibited random laser emission with the threshold as low as 0.52μJ/cm^(2),suggesting the wide prospective application in the field of flexible optoelectronic devices.

Alkyl-chain branched effect on the aggregation and photophysical behavior of polydiarylfluorenes toward stable deep-blue electroluminescence and efficient amplified spontaneous emission

The control of the condensed superstructure of light-emitting conjugated polymers(LCPs)is a crucial factor to obtain high performance and stable organic optoelectronic devices.Side-chain engineering strategy is an effective platform to tune inter chain aggregation and photophysical behaviour of LCPs.Herein,we systematically investigated the alkyl-chain branched effecton the conformational transition and photophysical behaviour of polydiarylfluorenes toward efficient blue optoelectronic devices.The branched side chain will improve materials solubility to inhibit interchain aggregation in solution according to DLS and optical analysis,which is useful to obtain high quality film.Therefore,our branched PEODPF,POYDPF pristine film present high luminance efficiency of 36.1%and 39.6%,enhanced about 20%relative to that of PODPF.Compared to the liner-type sides'chain,these branched chains also suppress chain planarization and improve film morphological stability effectively.Interestingly,the branched polymer also had excellent stable amplified spontaneous emission(ASE)behaviour with low threshold(4.72μJ/cm2)and a center peak of 465 nm,even thermal annealing at 220℃in the air atmosphere.Therefore,side-chain branched strategy for LCPs is an effective means to control interchain aggregation,film morphology and photophysical property of LCPs.

Acceptor Engineering Produces Ultrafast Nonradiative Decay in NIR-Ⅱ Aza-BODIPY Nanoparticles for Efficient Osteosarcoma Photothermal Therapy via Concurrent Apoptosis and Pyroptosis

Small-molecule photothermal agents(PTAs)with intense second near-infrared(NIR-Ⅱ,1,000 to 1,700 nm)absorption and high photothermal conversion efficiencies(PCEs)are promising candidates for treating deep-seated tumors such as osteosarcoma.To date,the development of small-molecule NIR-Ⅱ PTAs has largely relied on fabricating donor–acceptor–donor(D–A–D/D′)structures and limited success has been achieved.Herein,through acceptor engineering,a donor–acceptor–acceptor(D–A–A′)-structured NIR-Ⅱ aza-boron-dipyrromethene(aza-BODIPY)PTA(SW8)was readily developed for the 1,064-nm laser-mediated phototheranostic treatment of osteosarcoma.Changing the donor groups to acceptor groups produced remarkable red-shifts of absorption maximums from first near-infrared(NIR-Ⅰ)regions(~808 nm)to NIR-Ⅱ ones(~1,064 nm)for aza-BODIPYs(SW1 to SW8).Furthermore,SW8 self-assembled into nanoparticles(SW8@NPs)with intense NIR-Ⅱ absorption and an ultrahigh PCE(75%,1,064 nm).This ultrahigh PCE primarily originated from an additional nonradiative decay pathway,which showed a 100-fold enhanced decay rate compared to that shown by conventional pathways such as internal conversion and vibrational relaxation.Eventually,SW8@NPs performed highly efficient 1,064-nm laser-mediated NIR-Ⅱ photothermal therapy of osteosarcoma via concurrent apoptosis and pyroptosis.This work not only illustrates a remote approach for treating deep-seated tumors with high spatiotemporal control but also provides a new strategy for building high-performance small-molecule NIR-Ⅱ PTAs.

Elucidating the excited-state dynamics behavior in near-infrared Bodipy dye and aggregates toward biophotonics

Photo-induced excited-state dynamics within organic materials fundamentally determine their photophysical properties for various applications,and thus understanding the primary excited-state dynamics behavior is of fundamental and practical significance.Until recently,the excited-state dynamics of organic materials towards biophotonics have been rarely studied,although numerous endeavors have been devoted to the design of organic materials for biophotonics.Herein,various spectroscopy technologies including femtosecond transient absorption(fs-TA)spectroscopy clearly reveal a totally different excited state dynamics behavior within Bodipy monomer(2B-BDP dye)and aggregates(2B-BDP NPs),indicating strongly morphology dependent character.2B-BDP dye undergoes an ultrafast conversion from S1 to intramolecular charge transfer(ICT)state for subsequent photoluminescence(PL)and nonradiative(NR)decay,while 2B-BDP NPs show an accelerated excited-state deactivation mainly through S1→S0 NR decay.The potential bioapplications based on the corresponding excited state dynamics behavior are discussed together with experimental results.Interestingly,the accelerated NR decay in 2B-BDP NPs does not yield a stronger photoacoustic(PA)signal than that in 2B-BDP dye,which violates the conventional wisdom that faster NR decay would benefit the photothermal effects for better photoacoustic imaging(PAI).These insightful and fundamental observations of the excited-state dynamics may contribute an alternative approach at the molecular level towards the future design of functional Bodipy-based organic molecules with desirable performances.

Multilayer Porous Vanadium Nitride Microsheets Anodes for Highly Stable Na-ion Batteries

Sodiumion batteries(SIBs)have attracted intensive attention as promising alternative to lithium-ionbatteries(LIBs)for large scale energy storage systems because of low cost of sodium,similar energy storage mechanism and the reasonable performance.However,it is still a great challenge to search and design a robust structure of anode materials with excellent cycling stability and high rate capability for SIBs.Herein,multilayer porous vanadium nitride(VN)microsheets are synthesized through a facile and scalable hydrothermal synthesis-nitrogenization strategy as an effective anode material for SIBs.The multilayer porous VN microsheets not only offer more active sites for fast Na+insertion/extraction process and short diffusion pathway,but also effectively buffer the volume change of anode due to more space in the multilayer porous structure.The large proportions of capacitive behavior imply that the Na+charge storage depends on the intercalation pseudocapacitive mechanism.The multilayer porous VN microsheets electrodes manifest excellent cycling stability and rate capability,delivering a discharge capacity of 156.1 mA·h/g at 200 mA/g after 100 cycles,and a discharge capacity of 111.9 mA·h/g at 1.0 A/g even after 2300 cycles with the Coulombic efficiency of nearly 100%.

Self-assembly of Micrometer-long DNA Nanoribbons with Four Oligonucleotides

DNA nanostructures have found widespread applications in areas including nanoelectronics and biomedicine.However,traditional DNA origami needs a long single-stranded virus DNA and hundreds of short DNA strands,which make this method complicated and money-consuming.Here,we present a protocol for the assembly of DNA nanoribbons with only four oligonucleotides.DNA nanoribbons with different dimensions were successfully assembled with a 96-base scafford strand and three short staples.These biotinylated nanoribbons could also be decorated with streptavidins.This approach suggests that there exist great design spaces for the creation of simple nucleic acid nanostructures which could facilitate their application in plasmonic or drug delivery.

NIR-Ⅱ-absorbing conjugated polymer-based theranostic agent for NIR-Ⅱfluorescence imaging-guided photothermal therapy acting synergistically with tumor microenvironment-responsive nitric oxide therapy

Despite tremendous advances in gas therapy,there are major concerns about the inevitable concentration of toxicity and the ability to perform real-time tracking of drug delivery.Second near-infrared(NIR-Ⅱ)window absorbing nanoplatforms hold great promise for precision medicine because of their excellent tissue penetration of light and non-invasive nature.In this study,we engineered an NIR-Ⅱlaser-activated theranostic agent(named CP-bF@PEG)that was composed of amphiphilic polymers(Pluronic F127,with polyethylene glycol,PEG,moieties)coated with an NIR-Ⅱ-absorbing conjugated polymer(PTTBBT,CP)and nitric oxide(NO)donor(benzofuroxan,bF),which served as an NIR-Ⅱphotothermal inducer and NO nanogenerator.Under deep tissue penetration of NIR-Ⅱlaser irradiation,CP-bF@PEG was found to possess fluorescence imaging ability to accurately identify tumor and excellent photothermal effect.Moreover,CP-bF@PEG could generate NO via glutathione activation in the tumor microenvironment in a controllable manner.This NIR-Ⅱ-absorbing polymer for high-contrast NIR-Ⅱfluorescence imaging-guided precision photothermal therapy achieved synergistic effects with NO therapy,as evidenced by pronounced tumor therapeutic efficacy and few side effects.This nanotheranostic agent is a highly promising candidate for high-contrast NIR-Ⅱimaging-guided precision photothermal therapy combined with gas therapy against cancer.

超柔性薄膜有机半导体器件:从柔性到超柔性（英文）

柔性薄膜有机半导体器件由于其轻便、柔性、有机半导体的可重复制备及易于进行功能性调节、以及低成本、大面积溶液加工等特性而受到广泛关注.其中,弯曲半径不超过1 mm的超柔性电子对可折叠/便携设备、可穿戴设备、表皮及植入式电子设备、三维表面贴合型器件以及仿生学等领域的发展至关重要.本综述首先简要介绍了从柔性到超柔性电子的发展史以及超柔性有机器件的设计.接着,聚焦于超柔性的有机场效应管、有机发光二极管、有机太阳能电池以及有机存储器等有机半导体功能器件领域的最新进展进行了总结评述.

Nanoagent-based theranostic strategies against human coronaviruses

The emergence of human coronaviruses(HCoVs),especially the current pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),engender severe threats to public health globally.Despite the outstanding breakthrough of new vaccines and therapeutic medicines in the past years,HCoVs still undergo unpredictable mutations,thus demanding more effective diagnostic and therapeutic strategies.Benefitting from the unique physicochemical properties and multiple nano-bio interactions,nanomaterials hold promising potential to fight against various HCoVs,either by providing sensitive and economic nanosensors for rapid viral detection,or by developing translatable nanovaccines and broad-spectrum nanomedicines for HCoV treatment.Herein,we systemically summarized the recent applications of nanoagents in diagnostics and therapeutics for HCoV-induced diseases,as well as their limitations and perspectives against HCoV variants.We believe this review will promote the design of innovative theranostic nanoagents for the current and future HCoV-caused pandemics.

Afterglow Carbon Dots:From Fundamentals to Applications

The ability of carbon dots(CDs)to emit afterglow emission in addition to fluorescence in response to UV-to-visible excitation allows them to be a new class of luminescent materials.When compared with traditional organic or inorganic afterglow materials,CDs have a set of advantages,including small size,ease of synthesis,and absence of highly toxic metal ions.In addition,high dependence of their afterglow color output on temperature,excitation wavelength,and aggregation degrees adds remarkable flexibility in the creation of multimode luminescence of CDs without the need for changing their intrinsic attributes.These characteristics make CDs particularly attractive in the fields of sensing,anticounterfeiting,and data encryption.In this review,we first describe the general attributes of afterglow CDs and their fundamental afterglow mechanism.We then highlight recent strategic advances in the generation or activation of the afterglow luminescence of CDs.Considerable emphasis is placed on the summarization of their emergent afterglow properties in response to external stimulation.We further highlight the emerging applications of afterglow CDs on the basis of their unique optical features and present the key challenges needed to be addressed before the realization of their full practical utility.