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Epitaxial FeCo2O4 films were grown by pulsed laser deposition on Al2O3 (0001) substrates at different growth temperatures in this work. The growth temperature directly affects the occupation of cations and the lattice constant, resulting in different magnetic phases and conductivity. The optimal growth temperature range was 450–550 °C. Double bandgaps were observed in the UV absorption spectra. Electrical measurements showed that the film grown at 450 °C had the lowest activation energy, and the structure of this film was more ordered. The magnetic analysis demonstrated that, in addition to the ferrimagnetic phase formed by the antiparallel arrangement of the tetrahedral and octahedral magnetic moments, there were two kinds of antiferromagnetic phases. One kind of antiferromagnetism was from the antiphase boundaries, and the other was localized antiferromagnetism at the octahedra formed by the Co2+ ions. The three kinds of magnetic phases showed different characteristics with changes in the growth temperature and measurement temperature.

Water electrolysis is one of the most promising approaches for producing hydrogen. However, it has been hindered by the sluggishness of the anodic oxygen evolution reaction. In this work, we fabricated Ru-Co-Mn trimetallic alloy nanoparticles on N-doped carbon support (RuCoMn@NC) via the pyrolysis-adsorption-pyrolysis process using ZIF-67 as a precursor. The RuCoMn@NC catalyst exhibited excellent electrocatalytic performance for the hydrogen evolution reaction (HER) over a wide range of pH and glucose oxidation reaction in alkaline media. It showed exceptional HER activity in alkaline medium, superior to that of the commercial Pt/C catalyst (20 wt%), and good electrochemical stability. Further, a two-electrode alkaline electrolyzer pairing RuCoMn@NC as both cathode and anode was employed, and only a cell voltage of 1.63 V was required to attain a current density of 10 mA cm−2 in glucose electrolysis, which is about 270 mV lower than that in the overall water-splitting electrolyzer. This paper provides a promising method for developing efficiently bifunctional electrocatalysts driving redox electro-catalysis, and it would be beneficial to energy-saving electrolytic H2 production.

n-Type polymers with deep-positioned lowest unoccupied molecular orbital (LUMO) energy levels are essential for enabling n-type organic thin-film transistors (OTFTs) with high stability and n-type organic thermoelectrics (OTEs) with high doping efficiency and promising thermoelectric performance. Bithiophene imide (BTI) and its derivatives have been demonstrated as promising acceptor units for constructing high-performance n-type polymers. However, the electron-rich thiophene moiety in BTI leads to elevated LUMOs for the resultant polymers and hence limits their n-type performance and intrinsic stability. Herein, we addressed this issue by introducing strong electron-withdrawing cyano functionality on BTI and its derivatives. We have successfully overcome the synthetic challenges and developed a series of novel acceptor building blocks, CNI, CNTI, and CNDTI, which show substantially higher electron deficiencies than does BTI. On the basis of these novel building blocks, acceptor-acceptor type homopolymers and copolymers were successfully synthesized and featured greatly suppressed LUMOs (-3.64 to -4.11 eV) versus that (-3.48 eV) of the control polymer PBTI. Their deep-positioned LUMOs resulted in improved stability in OTFTs and more efficient n-doping in OTEs for the corresponding polymers with a highest electrical conductivity of 23.3 S cm

Low-cost and eco-friendly hole-transport materials (HTMs) are exceedingly desirable for the practical application of perovskite solar cells (PVSCs). Here, a traditional bidentate ligand (1,10-phenanthroline), widely used as a chelating agent for bioorganic reagents and probes, is incorporated into an HTM to afford M1. Such a planar bidentate ligand at the central core of the HTM can facilitate π–π stacking and enable chelation to Pb2+ ion defects and thus achieve efficient passivation at the M1/perovskite interface, contributing to reduced recombination loss. When employed as an HTM in inverted PVSCs without dopants, bidentate-ligand-based M1 yields a high power conversion efficiency (PCE) of 20.14%, which is significantly higher than that (18.32%) of the M0 analogue that contains phenanthrene. More importantly, green solvent processing (ethyl acetate) of M1 achieves a PCE of 19.21%, which is among the highest values reported in PVSCs with a green-solvent-processable HTM. Besides, the facile one-step synthesis route reduces the cost to 45 $ gram−1 for M1, which is cheaper than the most reported HTMs for high-efficiency PVSCs without dopants. These findings demonstrate the potential of bidentate ligands in developing cost-effective and eco-friendly HTMs toward highly efficient PVSCs.

Lattice-mismatch-directed hybrid metal@semiconductor core–shell nanocrystals with extended scope of diversity in composition and morphologies are critical to create more function integrations and applications. The case of metal@telluride hetero-nanostructures are more typical due to the electronegativity and electron affinity of tellurium, which are impediment of the telluride shell synthesis in the aqueous phase. Herein, we take advantage of the aqueous cation exchange (ACE) synthetic strategy, have synthesized Au@PbTe core–shell nanocrystals with engineering of amorphous/crystalline phase and shape evolution facilely. By controlling the kinetics of the ACE-enabled hydrothermal CE strategy and the starting phase/composition of Au@Ag2Te nanostructures, we also achieved core–shell to yolk–shell evolution with different Au core sizes and hollow PbTe shells. These plasmonic core–shell nanostructures with a suitable telluride shell thickness demonstrated potential applications in surface enhanced Raman scattering.

We synthesized Au@Cu2-xS core/shell nanorods (NRs) that have synergistic surface plasmon resonance (SPR) effects using a new cation exchange process in ethylene glycol (EG) phase. The dual effect - NIR photothermal and surface positive charge plasmon - of Au@Cu2-xS NRs, promote the capability to degrade Aβ1-42 fibrils into amorphous protein.

As a key component in perovskite solar cells (PVSCs), hole-transporting materials (HTMs) have been extensively explored and studied. Aiming to meet the requirements for future commercialization of PVSCs, HTMs which can enable excellent device performance with low cost and eco-friendly processability are urgently needed but rarely reported. In this work, a traditional anchoring group (2-cyanoacrylic acid) widely used in molecules for dye-sensitized solar cells is incorporated into donor-acceptor-type HTMs to afford MPA-BT-CA, which enables effective regulation of the frontier molecular orbital energy levels, interfacial modification of an ITO electrode, efficient defect passivation toward the perovskite layer, and more importantly alcohol solubility. Consequently, inverted PVSCs with this low-cost HTM exhibit excellent device performance with a remarkable power conversion efficiency (PCE) of 21.24% and good long-term stability in ambient conditions. More encouragingly, when processing MPA-BT-CA films with the green solvent ethanol, the corresponding PVSCs also deliver a substantial PCE as high as 20.52% with negligible hysteresis. Such molecular design of anchoring group-based materials represents great progress for developing efficient HTMs which combine the advantages of low cost, eco-friendly processability, and high performance. We believe that such design strategy will pave a new path for the exploration of highly efficient HTMs applicable to commercialization of PVSCs.

The open-circuit voltage (Voc) of all-polymer solar cells (all-PSCs) is typically lower than 0.9 V even for the most efficient ones. Large energy loss is the main reason for limiting Voc and efficiency of all-PSCs. Herein, through materials design using electron deficient building blocks based on bithiophene imides, the lowest unoccupied molecular orbital (LUMO) energy levels of polymer acceptors can be effectively tuned, which resulted in a reduced energy loss induced by charge generation and recombination loss due to the suppressed charge-transfer (CT) state absorption. Despite a negligible driving force, all-PSC based on the polymer donor and acceptor combination with well-aligned energy levels exhibited efficient charge transfer and achieved an external quantum efficiency over 10% while maintaining a large Voc of 1.02 V, leading to a 9.21% efficiency. Through various spectroscopy approaches, this work sheds light on the mechanism of energy loss in all-PSCs, which paves an avenue to achieving efficient all-PSCs with large Voc and drives the further development of all-PSCs.

Compared with p-type terpolymers, less effort has been devoted to n-type analogs. Herein, we synthesized a series of n-type terpolymers via incorporating three electron-deficient third components including thienopyrroledione (TPD), phthalimide, and benzothiadiazole into an imide-functionalized parent n-type copolymer to tune optoelectronic properties without sacrificing the n-type characteristics. Due to effects of the third components with different electron-accepting ability and solubility, the resulting three polymers feature distinct energy levels and crystallinity. In addition, heteroatoms (S, O, and N) attached on the third components trigger intramolecular noncovalent interactions, which can increase molecule planarity and have a significant effect on the packing structures of the polymer films. As a result, the best power conversion efficiency of 8.28% was achieved from all-polymer solar cells (all-PSCs) based on n-type terpolymer containing TPD. This is contributed by promoted electron mobility and face-on polymer packing, showing the pronounced advantages of the TPD used as a third component for thriving efficient n-type terpolymers. The generality is also successfully validated in a benchmark polymer donor/acceptor system by introducing TPD into the benchmark n-type polymer N2200. The results demonstrate the feasibility of introducing suitable electron-deficient building blocks as the third components for high-performance n-type terpolymers toward efficient all-PSCs.

The electron-transporting properties of n-type polymers strongly depend on the chemical and electronic structure of the electron-deficient building blocks. Here, we design and develop a novel elect...

Engineering the structure of core-shell colloidal semiconductor nanoparticles (CSNPs) is attractive due to the potential to enhance photo-induced charge transfer (PICT) and induce favourable optical and electronic properties. Nonetheless, the sensitivity of telluride CSNPs to high temperatures makes it challenging to precisely modulate their surface crystallinity. Herein, we have developed an efficient strategy for synthesising telluride CSNPs with thin amorphous shells using aqueous cation exchange (ACE). By changing the synthesis temperature in the range 40 to 110C, the crystallinity of the CdTe nanoparticles was controllable from perfect crystals with no detectable amorphous shell (c-CdTe) to a core-shell structure with a crystalline CdTe NP core covered by an amorphous shell of tunable thickness up to 7-8nm (c@a-CdTe) . A second ACE step transformed the c@a-CdTe to crystalline CdTe@HgTe core-shell NPs. The c@a-CdTe nanoparticles synthesized at 60C and having a 4-5 nm thick amorphous shell, exhibited the highest surface-enhanced Raman scattering activity with a high enhancement factor around 8.82x10^5, attributed to the coupling between the amorphous shell and the crystalline core., Comment: 15 pages, 5 figures, plus supplementary information

Type 2 diabetes mellitus (T2DM) is one of the major public health problems worldwide; both genetic and environmental factors are its risk factors. Arsenic, an environmental pollutant, might be a risk factor for T2DM, but the association of low-to-moderate level arsenic exposure with the risk of T2DM is still inconsistent. Single nucleotide polymorphisms (SNPs) can affect the development of T2DM, but the study on KEAP1 rs11545829 (GA) SNP is few. In this paper, we explored the effect of KEAP1 rs11545829 (GA) SNP and low-to-moderate level arsenic exposure on risk of T2DM in a cross-sectional case-control study conducted in Shanxi, China. Total of 938 participants, including 318 T2DM cases and 618 controls, were enrolled. Blood glycosylated haemoglobin (HbA1c) was detected by Automatic Biochemical Analyzer, and participants with HbA1c≧6.5% were diagnosed as T2DM. Urinary total arsenic (tAs, mg/L), as the indicator of arsenic exposure, was detected by liquid chromatography-atomic fluorescence spectrometry (LC-AFS). Genomic DNA was extracted and the genotypes of KEAP1 rs11545829 SNP were examined by multiplex polymerase chain reaction (PCR). The urinary tAs concentration in recruited participants was 0.075 (0.03-0.15) mg/L, and was associated with an increased risk of T2DM (OR = 8.45, 95% CI 2.63-27.17); rs11545829 mutation homozygote AA genotype had a protective effect on risk of T2DM (OR = 0.42, 95 % CI 0.25-0.73). Although this protective effect of AA genotype was found in participants with higher urinary tAs level (0.032 mg/L) (OR = 0.48, 95% CI 0.26-0.86), there was no interaction effect for arsenic exposure and rs11545829 SNP on risk of T2DM. In addition, BMI modified the association between rs11545829 SNP and the risk of T2DM (RERI = -1.11, 95% CI -2.18-0.04). The present study suggest that low-to-moderate level arsenic exposure may be a risk factor, while KEAP1 rs11545829 SNP mutation homozygote AA genotype may be a protective factor for risk of T2DM, especially for T2DM patients with urinary tAs level0.032 mg/L.

Intramolecular noncovalent interactions (INIs) have served as a powerful strategy for accessing organic semiconductors with enhanced charge transport properties. Herein, we apply the INI strategy for developing dopant-free hole-transporting materials (HTMs) by constructing two small-molecular HTMs featuring an INI-integrated backbone for high-performance perovskite solar cells (PVSCs). Upon incorporating noncovalent S⋅⋅⋅O interaction into their simple-structured backbones, the resulting HTMs, BTORA and BTORCNA, showed self-planarized backbones, tuned energy levels, enhanced thermal properties, appropriate film morphology, and effective defect passivation. More importantly, the high film crystallinity enables the materials with substantial hole mobilities, thus rendering them as promising dopant-free HTMs. Consequently, the BTORCNA-based inverted PVSCs delivered a power conversion efficiency of 21.10 % with encouraging long-term device stability, outperforming the devices based on BTRA without S⋅⋅⋅O interaction (18.40 %). This work offers a practical approach to designing charge transporting layers with high intrinsic mobilities for high-performance PVSCs.

To understand the potential roles of terrestrial bamboo on controlling cyanobacterial blooms in aquatic systems, growth rates of the cyanobacterium Microcystis aeruginosa and its competitor algae were examined under different concentrations of bamboo extract. In mono-species cultures with unicellular algal strains, 5.0 g L−1 extract treatment suppressed M. aeruginosa growth, while it had little effect on the growth of green alga Scenedesmus obliquus or promoted the growth of diatom Nitzschia palea. In co-species cultures, the extract treatment increased the effect of S. obliquus and N. palea on the growth of M. aeruginosa. Under the extract treatment with a field-collected M. aeruginosa population, its cell density declined and its colony was etiolated and sank, while co-cultured N. palea increased explosively by invading the colony. These results suggest that bamboo forest stands along banks and artificially installed bamboo poles can affect the aquatic environment for phytoplankton community. Enhancing the growth of competitors, especially diatoms that can invade cyanobacterial colonies, by using extracts or by providing substrates for growth, was suggested to be the major way of the bloom control by bamboo.

A planar backbone conformation is essential for enabling polymer semiconductors with high charge carrier mobility in organic thin-film transistors. Benefiting from the smaller van der Waals radius ...

Conductive polyelectrolytes such as P3CT-Na have been widely used as efficient hole-transporting layers (HTLs) in inverted perovskite solar cells (PSCs) due to their high hole mobility. However, the acid-base neutralization reaction is indispensable for preparing such polyelectrolytes and the varied content of cations usually leads to poor reproducibility of the device performance in PSCs. In this work, a commercially available polymer poly[3-(4-carboxybutyl)thiophene-2,5-diyl] (P3CT) was directly applied as an HTL in PSCs for the first time. Encouragingly, it was found that due to the dual functionality of carboxyl groups on side chains, a thin layer of P3CT can not only strongly anchor on ITO electrode and optimize its work function but also show an effective passivation effect toward perovskite active layer. Benefiting from such dual functionality, a uniform perovskite film with better quality was obtained on P3CT. As a result, the P3CT-based PSCs show much lower nonradiative recombination and achieve a champion power conversion efficiency (PCE) of 21.33% with a high fill factor (FF) of 83.6%. Impressively, as the device area is increased to 0.80 cm2, a PCE of 19.65% can still be obtained for the PSCs based on P3CT HTL. Our work provides important strategy for developing HTLs for high-performance PSCs.

To investigate the potential association between BMP2 single nucleotide polymorphisms (SNPs) and brick-tea-type skeletal fluorosis risk in cross-sectional case-control study conducted in Sinkiang and Qinghai, China, a total of 598 individuals, including 308 Tibetans and 290 Kazakhs, were enrolled. Using the standard WS/192-2008 (China), 221 skeletal fluorosis cases were diagnosed, including 123 Tibetans and 98 Kazakhs. Logistic regressions 2 analysis did not find the association between SNPs (Rs235764, Rs235739 and Rs996544) and skeletal fluorosis. Genetic models, linkage disequilibrium (LD) and haplotype analysis were not found to be associated with risk of skeletal fluorosis after adjustment by age and sex (P0.05).Our data suggested that Rs 235764, Rs 235739 and Rs 996544 were not linked susceptibility for skeletal fluorosis in our cross-sectional case-control study.

The mobile robot is moved by receiving instructions through wireless communication, and the particle filter is used to simultaneous localization and mapping. Aiming at the problem of the degradation of particle filter weights and loss of particle diversity, which leads to the decrease of filter accuracy, this paper uses the plant cell swarm algorithm to optimize the particle filter. First of all, combining the characteristics of plant cells that affect the growth rate of cells when the auxin content changes due to light stimulation realizes the optimization of the particles after importance sampling, so that they are concentrated in the high-likelihood area, and the problem of particle weight degradation is solved. Secondly, in the process of optimizing particle distribution, the auxin content of each particle is different, which makes the optimization effect on each particle different, so it effectively solves the problem of particle diversity loss. Finally, a simulation experiment is carried out. During the experiment, the robot moves by receiving control commands through wireless communication. The experimental results show that the algorithm effectively solves the problem of particle weight degradation and particle diversity loss and improves the filtering accuracy. The improved algorithm is verified in the simultaneous localization and mapping of the robot, which effectively improves the robot’s performance at the same time positioning accuracy. Compared with the classic algorithm, the robot positioning accuracy is increased by 49.2%. Moreover, the operational stability of the algorithm has also been improved after the improvement.

Here we show a novel strategy for tailoring the synergistic electrical properties of metal@semiconductor hybrid nanocrystals (HNCs) based on cation exchange-enabled electronic doping. As a demonstration, the conductive nature of Au@CdS core–shell HNCs was changed from n- to p-type by introducing Cu dopants into the CdS shell. The dependence of the conductivity type on the dopant concentration in the HNCs is disclosed by combined photoelectrochemical (PEC) studies. Moreover, a tandem PEC cell consisting of an undoped Au@CdS photoanode and a Cu-doped Au@CdS photocathode respectively modified with cocatalysts is fabricated, which displayed stable H2 and O2 evolution in unassisted PEC overall water splitting.

Two new wide bandgap copolymers PTzTIBDTT and PTzTIBDTT-S based on thiazolothienyl imide (TzTI) and benzodithiophene with a distinct side chain were synthesized and characterized for applications in polymer solar cells (PSCs). The single crystal of the TzTI model compound showed a highly planar backbone with a close π-stacking distance of 3.65 A, a desired structural feature for efficient charge transport. Moreover, the TzTI incorporation can trigger intramolecular noncovalent N⋯S interactions to yield a self-planarized polymer backbone, which should be beneficial for achieving ordered molecular packing and efficient charge transport. Due to its strong electron-withdrawing effect, the incorporation of the TzTI unit largely lowers the polymer HOMO levels to −5.65 and −5.69 eV for PTzTIBDTT and PTzTIBDTT-S, respectively. The PSCs containing the PTzTIBDTT:PC71BM active layer exhibited a promising power conversion efficiency (PCE) of 8.00% with a large Voc of 0.90 V. To the best of our knowledge, the PCE is among the highest values for fullerene PSCs based on an imide-containing polymer donor. This work not only demonstrates that thiazolothienyl imide is a promising building block for constructing high-performance wide bandgap photovoltaic polymer semiconductors, but also reveals that a noncovalent N⋯S conformational lock is an effective molecular design approach for enabling polymer semiconductors with a planar backbone for efficient PSCs.

A new indacenodithiophene-based acceptor–donor–acceptor (A–D–A) type nonfullerene acceptor material ITBTC, featuring a conjugation-extended benzo[b]thiophene-fused end group, was designed and synthesized. Compared to the well known phenyl-fused ITIC acceptor containing a 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile (IC) end group, incorporation of an additional electron-rich thiophene into the IC moiety decreased the electron-accepting strength of the end group and increased the intermolecular interactions of ITBTC molecules. As a result, ITBTC exhibited an elevated lowest unoccupied molecular orbital, an improved electron mobility, and a more favorable blend film morphology. Despite its slightly blue-shifted absorption, the photocurrent of ITBTC-based devices was well-maintained due to the extra absorption band in the short wavelength range, which is induced by its conjugation-extended end group. Benefitting from these characteristics, the ITBTC-based solar cells achieved an enhanced power conversion efficiency (PCE) of 10.99% with a simultaneously improved open-circuit voltage (Voc, 0.94 V) and fill factor (FF, 71.3%) and well-maintained short-circuit current density (Jsc, 16.37 mA cm−2), compared to those of the ITIC-based devices (PCE of 9.53%). These results suggest that extending the π-conjugation of end group through thiophene incorporation is an efficient approach for optimizing both the energy level alignment and intermolecular interaction of the acceptor materials while maintaining their efficient light-harvesting ability. Our study also demonstrates the great potential of the new benzo[b]thiophene-fused end group for constructing high-performance nonfullerene acceptors and provided insight into overcoming the trade-off between Jsc and Voc to realize simultaneously enhanced photovoltaic parameters.

Thiophene and its derivatives have been extensively used in organic electronics, particularly in the field of polymer solar cells (PSCs). Significant research efforts have been dedicated to modifying thiophene-based units by attaching electron-donating or withdrawing groups to tune the energy levels of conjugated materials. Herein, we report the design and synthesis of a novel thiophene derivative, FE-T, featuring a monothiophene functionalized with both an electron-withdrawing fluorine atom (F) and an ester group (E). The FE-T unit possesses distinctive advantages of both F and E groups, the synergistic effects of which enable significant downshifting of the energy levels and enhanced aggregation/crystallinity of the resulting organic materials. Shown in this work are a series of polymers obtained by incorporating the FE-T unit into a PM6 polymer to fine-tune the energetics and morphology of this high-performance PSC material. The optimal polymer in the series shows a downshifted HOMO and an improved morphology, leading to a high PCE of 16.4% with a small energy loss (0.53 eV) enabled by the reduced non-radiative energy loss (0.23 eV), which are among the best values reported for non-fullerene PSCs to date. This work shows that the FE-T unit is a promising building block to construct donor polymers for high-performance organic photovoltaic cells.

Understanding the conformation effect on molecular packing, miscibility, and photovoltaic performance is important to open a new avenue for small-molecule acceptor (SMA) design. Herein, two novel acceptor-(donor-acceptor1-donor)-acceptor (A-DA1D-A)-type asymmetric SMAs are developed, namely C-shaped BDTP-4F and S-shaped BTDTP-4F. The BDTP-4F-based polymer solar cells (PSCs) with PM6 as donor, yields a power conversion efficiency (PCE) of 15.24%, significantly higher than that of the BTDTP-4F-based device (13.12%). The better PCE for BDTP-4F-based device is mainly attributed to more balanced charge transport, weaker bimolecular recombination, and more favorable morphology. Additionally, two traditional A-D-A-type SMAs (IDTP-4F and IDTTP-4F) are also synthesized to investigate the conformation effect on morphology and device performance. Different from the device result above, here, IDTP-4F with S-shape conformation outperforms than IDTTP-4F with C-shape conformation. Importantly, it is found that for these two different types of SMA, the better performing binary blend has similar morphological characteristics. Specifically, both PM6:BDTP-4F and PM6:IDTP-4F blend exhibit perfect nanofibril network structure with proper domain size, obvious face-on orientation and enhance donor-acceptor interactions, thereby better device performance. This work indicates tuning molecular conformation plays pivotal role in morphology and device effciciency, shining a light on the molecular design of the SMAs.

Long-term excessive exposure to fluoride from environmental sources can cause serious public health problems such as dental fluorosis and skeletal fluorosis. The aberrant activation of osteoblasts in the early stage is one of the critical steps during the pathogenesis of skeletal fluorosis and canonical Wnt signaling pathway participate in the progress. However, the specific mechanism that how canonical Wnt signaling pathway was mediated is not yet clear. In this study, we found that miR-21-5p induced the activation of canonical Wnt signaling pathway via targeting PTEN and DKK2 during fluoride induced osteoblasts activation and firstly demonstrated the forward loop between canonical Wnt signaling and miR-21-5p in the process. These findings suggested an important regulatory role of miR-21-5p on canonical Wnt signaling pathway during skeletal fluorosis and miR-21-5p might be a potential therapeutic target for skeletal fluorosis.

In this paper, the magnetostructural transformation from paramagnetic austenite to ferromagnetic martensite is described as a synergistic-type phase transformation because the structural and magnetic subsystems exhibit two unique synergistic effects: (1) lattice vibration and magnetic entropy changes synergistically contribute to the total entropy change; (2) the structure and magnetism synergistically response to external cross-fields. Such synergistic-type phase transformation has been explored in Ni-Mn-Ga-X (X = Sn, Sb) Heusler alloys. By the substitution of Sn/Sb for Ga, a temperature window of 50 K for the synergistic-type phase transformation has been established in the phase diagram of Ni-Mn-Ga-X (X = Sn, Sb). Associated with the synergistic contribution of lattice vibration and magnetic entropy changes, the samples exhibit high phase transformation entropy changes (≥1.2 J/molK) within the temperature window. The synergistic effects of the magnetostructural transformation make the Ni-Mn-Ga-X (X = Sn, Sb) alloys to be potential multicaloric materials.

A straightforward approach was proposed to modify cotton fabric for oil/water separation based on musselinspired reaction. The poly(DMA-Octadecyl acrylate) was designed to contain key chemical constituents present in mussel adhesive proteins by free radical polymerization of dopamine hydrochloride and octadecyl acrylate, which strongly adsorbed to fabric substrates, providing a special surface for fabric. The chemical structure, surface topography, and surface wettability of the fabric were characterized. The results showed that as-prepared cotton fabric displayed a high CA of >150° when dripped water droplets were on the modified fabric surface, and the oil contact angle (OCA) was close to 0°, it had excellent potential to be used in practical applications and has created a new method of fabric modification for oil/water separation.

Imide functionalization is one of the most effective approaches to develop electron-deficient building blocks for constructing n-type organic semiconductors. Driven by the attractive properties of imide-functionalized dithienylbenzodiimide (TBDI) and the promising device performance of TBDI-based polymers, a novel acceptor with increased electron affinity, fluorinated dithienylbenzodiimide (TFBDI), was designed with the hydrogen replaced by fluorine on the benzene core, and the synthetic challenges associated with this highly electron-deficient fluorinated imide building block are successfully overcome. TFBDI showed suppressed frontier molecular orbital energy levels as compared with TBDI. Copolymerizing this new electron-withdrawing TBDI with various donor co-units afforded a series of n-type polymer semiconductors TFBDI-T, TFBDI-Se, and TFBDI-BSe. All these TFBDI-based polymers exhibited a lower-lying lowest unoccupied molecular orbital (LUMO) energy level than the polymer analogue without fluorine. When applied in organic thin-film transistors, three polymers showed unipolar electron transport with large on-current/off-current ratios (

Currently, n-type acceptors in high-performance all-polymer solar cells (all-PSCs) are dominated by imide-functionalized polymers, which typically show medium bandgap. Herein, a novel narrow-bandgap polymer, poly(5,6-dicyano-2,1,3-benzothiadiazole-alt-indacenodithiophene) (DCNBT-IDT), based on dicyanobenzothiadiazole without an imide group is reported. The strong electron-withdrawing cyano functionality enables DCNBT-IDT with n-type character and, more importantly, alleviates the steric hindrance associated with typical imide groups. Compared to the benchmark poly(naphthalene diimide-alt-bithiophene) (N2200), DCNBT-IDT shows a narrower bandgap (1.43 eV) with a much higher absorption coefficient (6.15 × 104 cm-1 ). Such properties are elusive for polymer acceptors to date, eradicating the drawbacks inherited in N2200 and other high-performance polymer acceptors. When blended with a wide-bandgap polymer donor, the DCNBT-IDT-based all-PSCs achieve a remarkable power conversion efficiency of 8.32% with a small energy loss of 0.53 eV and a photoresponse of up to 870 nm. Such efficiency greatly outperforms those of N2200 (6.13%) and the naphthalene diimide (NDI)-based analog NDI-IDT (2.19%). This work breaks the long-standing bottlenecks limiting materials innovation of n-type polymers, which paves a new avenue for developing polymer acceptors with improved optoelectronic properties and heralds a brighter future of all-PSCs.

Halogenated solvents are prevailingly used in the fabrication of nonfullerene organic solar cells (NF-OSCs) at the current stage, imposing significant restraints on their practical applications. By copolymerizing phthalimide or thieno[3,4

Significant progress has been made in nonfullerene small molecule acceptors (NF‐SMAs) that leads to a consistent increase of power conversion efficiency (PCE) of nonfullerene organic solar cells (NF‐OSCs). To achieve better compatibility with high‐performance NF‐SMAs, the direction of molecular design for donor polymers is toward wide bandgap (WBG), tailored properties, and preferentially ecofriendly processability for device fabrication. Here, a weak acceptor unit, methyl 2,5‐dibromo‐4‐fluorothiophene‐3‐carboxylate (FE‐T), is synthesized and copolymerized with benzo[1,2‐b:4,5‐b′]dithiophene (BDT) to afford a series of nonhalogenated solvent processable WBG polymers P1‐P3 with a distinct side chain on FE‐T. The incorporation of FE‐T leads to polymers with a deep highest occupied molecular orbital (HOMO) level of −5.60−5.70 eV, a complementary absorption to NF‐SMAs, and a planar molecular conformation. When combined with the narrow bandgap acceptor ITIC‐Th, the solar cell based on P1 with the shortest methyl chain on FE‐T achieves a PCE of 11.39% with a large V oc of 1.01 V and a J sc of 17.89 mA cm−2. Moreover, a PCE of 12.11% is attained for ternary cells based on WBG P1, narrow bandgap PTB7‐Th, and acceptor IEICO‐4F. These results demonstrate that the new FE‐T is a highly promising acceptor unit to construct WBG polymers for efficient NF‐OSCs., A series of wide bandgap donor polymers are designed and synthesized by incorporating a monothiophene functionalized with both a fluorine atom and an ester group. Fabricated from nonhalogenated solvent, power conversion efficiencies of 11.39% and 12.11% are achieved for binary and ternary nonfullerene solar cells, respectively.

Molecular doping of organic semiconductors creates Coulombically bound charge and counterion pairs through a charge-transfer process. However, their Coulomb interactions and strategies to mitigate their effects have been rarely addressed. Here, we report that the number of free charges and thermoelectric properties are greatly enhanced by overcoming the Coulomb interaction in an n-doped conjugated polymer. Poly(2,2'-bithiazolothienyl-4,4',10,10'-tetracarboxydiimide) (PDTzTI) and the benchmark N2200 are n-doped by tetrakis (dimethylamino) ethylene (TDAE) for thermoelectrics. Doped PDTzTI exhibits similar to 10 times higher free-charge density and 500 times higher conductivity than doped N2200, leading to a power factor of 7.6 mu W m(-1) K-2 and ZT of 0.01 at room temperature. Compared to N2200, PDTzTI features a better molecular ordering and two-dimensional charge delocalization, which help overcome the Coulomb interaction in the doped state. Consequently, free charges are more easily generated from charge-counterion pairs. This work provides a strategy for improving n-type thermoelectrics by tackling electrostatic interactions.

A three-dimensional model of a circular casting mold with a vibrating nucleus generator was established, and the characteristics of temperature and flow fields during the solidification process of ferritic stainless steel Cr17 in the casting mold were analyzed using finite element and finite difference methods. A standard k-&epsilon, turbulent current model was adopted to simulate the temperature field, and a standard k-&epsilon, model in Reynolds-averaged Navier&ndash, Stokes equations (RANS) was employed to deal with the flow field. The temperature field diffuses outward with a positive temperature gradient. Low degrees of undercooling can prevent solidified shells from forming rapidly on the surface of the nucleus generator. The temperature perpendicular to the direction of vibration is lower than that in the direction of vibration. The flow field exhibits a heart-shaped distribution and spreads gradually outward. The uniform distribution of grains can be achieved at three different frequencies of vibration. The results show that the degree of undercooling affects the distribution of the temperature field while the frequency of vibration affects the flow field significantly. Under the conditions of undercooling of 540 K and vibration frequency of 1000 Hz, the region perpendicular to the vibration direction of the nucleus generator is the optimum area for equiaxed crystal formation.

Biselenophene (BS) is generally considered as a promising building block for constructing organic semiconductors, and the 3-positions of selenophene in BS offer a great opportunity for further structural modification. Herein, a novel fluorinated biselenophene, 3,3′-difluoro-2,2′-biselenophene (BSF), was designed and synthesized successfully, and subsequently incorporated into a polymer backbone leading to the resulting polymer PNDIBSF. The polymer backbone planarity was significantly improved via the enhanced intramolecular noncovalent Se⋯F coulombic interactions. Meanwhile, the electronic structure of the polymer was effectively tuned by the high electronegativity of F atoms. All-polymer solar cells (all-PSCs) with J71 and PNDIBSF as polymer donor and acceptor achieved power conversion efficiency (PCE) of 5.20%. In comparsion, all-PSCs based on the nonfluorinated analogue polymer acceptor (PNDIBS) had low PCE of 2.74%. The results demonstrated that BSF is a promising building block for constructing polymer acceptor in all-PSCs, and the fluorination offers a sufficient strategy for further improving performance of selenophene-based polymer semiconductors.