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InP quantum dots (QDs) are regarded as the most promising star material to replace Cd-based QDs due to their excellent properties of low toxicity and tunable luminescence in the visible to infrared range. Red and green InP QDs have been shown to have excellent performance comparable to that of Cd-based QDs, but in contrast, blue InP QDs are still lagging behind. The smaller size of the core is a challenge for synthesizing high-performance blue InP QDs compared with red and green QDs. In this study, deep blue-emitting InP QDs were synthesized using a cheaper and safer phosphorus source: tris-(dimethylamino)-phosphine ((DMA)3P). A double Zn and Ga modification was applied to modulate the emission of InP QDs. A strategy for synthesizing deep blue luminescent In-(ZnGa)P QDs was proposed, and Zn-(Ac)2 was used as a precursor to react with (DMA)3P to synthesize blue InP QDs. Doping elemental Zn during nucleation inhibited the growth of the InP crystals and narrowed the lattice. Then, the Ga element further increases the material band gap by cation exchange. By introducing GaI3 into the synthesis process and utilizing the cation-exchange mechanism, deep blue emission InP QDs was realized. Tunable deep blue emission of InP QDs changed from 478 to 447 nm was achieved by this strategy. Specially, an 84% photoluminescent quantum yield is obtained for 457 nm emission QDs. This study provides clues for InP QDs to be emitted in the deep blue region, with the aim of constructing efficient deep blue QDs light-emitting diodes. [ABSTRACT FROM AUTHOR]

SnO2 nanoparticles (NPs) have been used as an electron transport layer (ETL) in quantum dot light-emitting diodes (QLEDs) to achieve stable and high-performance devices. However, SnO2 NPs with high electron mobility cause the problem of imbalanced charge injection and transport in QLEDs. Meanwhile, the SnO2 NPs synthesized at low temperature have hydroxyl (−OH) groups, which could damage the performance of QLEDs. Here, Zn doping was applied to modulate the properties of SnO2 NPs and achieve better carrier balance in green CdSe/ZnS QLED. The maximum current efficiency (CE) of QLED with 5 wt % Zn-doped SnO2 NPs is 2.3-fold higher than that of SnO2-based QLED. In addition, a small-molecule 4,4′-bis-(carbazole-9-yl)-1,1′-biphenyl (CBP)-mixed poly-(9-vinylcarbazole) (PVK) layer was used as a hole transport layer to facilitate the hole injection and charge balance. As a result, a maximum external quantum efficiency (EQE) of 5.03% is obtained for the best performance device. The T50 lifetime at a luminance of 100 cd/m2, for a device based on 5 wt % Zn-doped SnO2 ETL, is 9141 h, which is 2.29-fold longer than the reference one. This work provides a new strategy to obtain high-performance and stable display arrays. [ABSTRACT FROM AUTHOR]

Our recently developed improved united atom force fieldshows a good quality to reproduce both the static and transport propertiesof neat ionic liquids (ILs). Combined with the TIP4P-Ew water model,the force field is used to simulate the mixture of 1-butyl-3-methylimidazoliumtetrafluoroborate ([C4mim][BF4]) and water withoutfurther optimization to adjust any cross parameters. Liquid densitiesof the mixture are well predicted over the entire concentration rangeat temperatures from 298.15 to 353.15 K. Simulations also reproducethe positive values of excess volumes and excess enthalpies, as wellas their increase with temperature. The simulated viscosities arein good agreement with experimental values, especially in the water-richregion. We found three distinct regions by analyzing the concentrationdependent self-diffusion coefficients via Stokes–Einstein (SE)relation, indicating the mixture experiences significant microheterogeneitywith the adding of water. This observation is well connected to thestructure features obtained in simulations, such as radial distributionfunctions (RDFs), spatial distribution functions (SDFs) and waterclustering analysis. At the water mole fraction (x2) less than 0.2, most of the water molecules are isolatedin the polar cation–anion network in ionic liquids. With theincrease of x2from 0.2 to 0.8, largewater cluster forms and eventually percolates the whole system. When x2> 0.8, ionic liquids show a moderate degreeof aggregation (with maximum around 0.9 to 0.95) before the cationsand anions are fully dissolved in water. [ABSTRACT FROM AUTHOR]

Saturate (Sa), the lightest component in fluid catalytic cracking (FCC) slurry oil, exhibits a poorly understood influence on the formation and development of mesophase, thereby constraining the production of premium-quality mesophase pitch. To address this issue, Sa is isolated from FCC slurry oil, and its concentration is modulated to investigate its impact on the formation and development of mesophase. The results indicate that Sa contains a high concentration of long alkane side chains and naphthenic structures, which render it an effective "lubricant" and "activator" within the reaction system. The addition of a small amount of Sa (≤5 wt %) maintains a low viscosity state of the reaction system, further facilitating the migration of aromatic molecules and promoting mesophase formation. It is crucial to note that excessive amounts of Sa (>10 wt %) significantly reduce the aromaticity and reactivity of the reaction system, further delaying the formation of mesophase. The reaction system exhibits moderate aromaticity and reactivity with low viscosity at 10 wt % Sa, leading to the formation of mesophase pitch with a moderate softening point (270 °C) and a wide-area optical texture (anisotropy length >60 μm, width >10 μm) within a short time of 6 h. This work establishes a robust theoretical foundation for producing premium-quality mesophase pitch through the regulation of raw material components., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Silicon has the potential to improve lithium-ion battery (LIB) performance substantially by replacing graphite as an anode. The sustainability of such a transformation, however, depends on the source of silicon and the nature of the manufacturing process. Today's silicon industry still overwhelmingly depends on the energy-intensive, high-temperature carbothermal reduction of silica─a process that adversely impacts the environment. Rather than use conventional thermoreduction alone to break Si-O bonds, we report the efficient conversion of SiO 2 directly to Mg 2 Si by a microwave-induced Mg plasma within 2.5 min at merely 200 W under vacuum. The underlying mechanism is proposed, wherein electrons with enhanced kinetics function readily as the reductant while the "bombardment" from Mg cations and electrons promotes the fast nucleation of Mg 2 Si. The 3D nanoporous (NP) Si is then fabricated by a facile thermal dealloying step. The resulting hierarchical NP Si anodes deliver stable, extended cycling with excellent rate capability in Li-ion half-cells, with capacities several times greater than graphite. The microwave-induced metal plasma (MIMP) concept can be applied just as efficiently to the synthesis of Mg 2 Si from Si, and the chemistry should be extendable to the reduction of multiple metal(loid) oxides via their respective Mg alloys.

Although the emerging interfacial solar steam generation technology is sustainable and eco-friendly for generating clean water by desalinating seawater and purifying wastewaters, salt deposition on the evaporation surface during solar-driven evaporation severely degrades the purification performances and adversely affect the long-term performance stability of solar steam generation devices. Herein, to construct solar steam generators for efficient solar steam generation and seawater desalination, three-dimensional (3D) natural loofah sponges with both macropores of the sponge and microchannels of the loofah fibers are hydrothermally decorated with molybdenum disulfide (MoS 2 ) sheets and carbon particles. Benefiting from fast upward transport of water, rapid steam extraction, and effective salt-resistant capacity, the 3D hydrothermally decorated loofah sponge with MoS 2 sheets and carbon particles (HLMC) with an exposed height of 4 cm can not only obtain heat by its top surface under the downward solar light irradiation based on the solar-thermal energy conversion but also gain environmental energy by its porous sidewall surface, achieving a competitive water evaporation rate of 3.45 kg m -2 h -1 under 1 sun irradiation. Additionally, the 3D HLMC evaporator exhibits long-term desalination stability during the solar-driven desalination of an aqueous salt solution with 3.5 wt % NaCl for 120 h without apparent salt deposition because of its dual type of pores and uneven structure distribution.

Ferroelectrics with negative capacitance effects can amplify the gate voltage in field-effect transistors to achieve low power operation beyond the limits of Boltzmann's Tyranny. The reduction of power consumption depends on the capacitance matching between the ferroelectric layer and gate dielectrics, which can be well controlled by adjusting the negative capacitance effect in ferroelectrics. However, it is a great challenge to experimentally tune the negative capacitance effect. Here, the observation of the tunable negative capacitance effect in ferroelectric KNbO 3 through strain engineering is demonstrated. The magnitude of the voltage reduction and negative slope in polarization-electric field ( P - E ) curves as the symbol of negative capacitance effects can be controlled by imposing various epitaxial strains. The adjustment of the negative curvature region in the polarization-energy landscape under different strain states is responsible for the tunable negative capacitance. Our work paves the way for fabricating low-power devices and further reducing energy consumption in electronics.

BiFeO 3 -BaTiO 3 (BF-BT) dielectric ceramics are receiving more and more concern for advanced energy storage devices owing to their excellent ferroelectric properties and environmental sustainability. However, the energy density and efficiency are limited in spite of the large remanent polarization. Herein, we proposed a multiscale optimization strategy via a local compositional disorder with a Birich content and nanodomain engineering by introducing the Sr 0.7 Bi 0.2 Ca 0.1 TiO 3 (SBCT) into BF-BT ceramics. Interestingly, an extraordinary energy storage property (ESP) with a high reversible energy storage density ( W rec ) of ∼3.79 J/cm 3 and an ultrahigh polarization discrepancy (Δ P ) of ∼58.5 μC/cm 2 were obtained in the SBCT-modified BF-BT ceramics under 160 kV/cm. The boosted ESP should be attributed to the fact that the replacement of A/B-sites cations could transform the long-range ferroelectric order of the BF-BT system into polar nanoregions (PNRs) along with the refined grain size, decreased leakage current, and broadened energy band gap. Moreover, good frequency (1-10 3 Hz) and temperature (25-125 °C) stabilities, high fatigue resistance (× 10 5 ), large power density (∼31.1 MW/cm 3 ), and fast discharge time (∼97 ns) were also observed for the optimized ceramics. These results illustrate a potentially effective method for creating high ESP lead-free ceramics at a low electric field.

While using ferroelectric polarization to tune the functional properties of 2D materials has been extensively studied recently, the effects of 2D materials on the ferroelectricity and piezoelectricity of ferroelectrics are much less explored. In this work, we report markedly enhanced ferroelectric and piezoelectric properties of graphene/Pb(Zr 0.52 Ti 0.48 )O 3 /SrRuO 3 (GR/PZT/SRO) capacitors. Compared with conventional metal-electroded ferroelectric capacitors, the GR/PZT/SRO capacitors exhibit more abrupt polarization switching, larger switchable polarization, lower leakage current, and smaller coercive voltage. Moreover, with graphene electrodes, the ferroelectric properties of PZT capacitors are much more stable against aging. The enhanced ferroelectric behaviors in GR/PZT/SRO capacitors can be attributed to an improved interface with fewer defects and inhibited growth of defective interfacial layer resulting from the graphene protection. Because of the atomic thickness and extraordinary mechanical flexibility of graphene, the piezoelectric response in PZT with graphene electrode is about four times larger than the one with an Au electrode. Our findings on the enhanced ferroelectric and piezoelectric properties of PZT with 2D electrodes advance the understanding of the 2D/PZT interface and provide solutions for developing high-performance ferroelectrics devices.

With the aging of the population, postmenopausal osteoporosis becomes increasingly widespread and severe as fractures caused by osteoporosis may lead to permanent disabilities and even death. Inspired by extracellular vesicles that participate in bone remodeling, we present a biomimicking polymer vesicle for bone-targeted β-estradiol (E 2 ) delivery. This vesicle is self-assembled from a poly(ε-caprolactone) 28 - block -poly[(l-glutamic acid) 7 - stat -(l-glutamic acid-alendronic acid) 4 ] (PCL 28 - b -P[Glu 7 - stat -(Glu-ADA) 4 ]) diblock copolymer. The alendronic acid (ADA) on the coronas endows the polymer vesicles with a high bone affinity and acts synergistically with E 2 to achieve an enhanced therapeutic effect. As confirmed with ovariectomized osteoporosis rat models, bone loss was significantly reversed as the recovery rates of total BMD (bone mineral density) and trabecular BMD were 70.4% and 99.3%, respectively. Overall, this work provides fresh insight into the treatment of osteoporosis.

A capping layer is known to be critical for stabilizing the ferroelectric (FE) orthorhombic phase (o-phase) in a HfO 2 -based thin film. Here, vanadium oxide (VO x ), a functional oxide exhibiting the insulator-metal transition, is used as a novel type of a capping layer for the Hf 0.5 Zr 0.5 O 2 (HZO) thin film. It is demonstrated that the VO x capping layer (VCL) can enhance the FE properties of the HZO thin film comprehensively. Specifically, the HZO thin film with a VCL shows large remanent polarization (2 P r ≈36.9 μC/cm 2 ), relatively small coercive field ( E c ≈1.09 MV/cm), high endurance (up to 10 9 cycles), and long retention (>10 5 seconds). The enhanced FE properties may be attributed to the VCL-induced stabilization of the FE o-phase and suppression of oxygen vacancies at the interface. Furthermore, the HZO thin film with a VCL exhibits a successive rightward shift of polarization-voltage ( P-V ) hysteresis loop as the temperature increases. This is well correlated with the insulator-metal transition in a VCL, which can modulate the interfacial built-in field and thus cause the P-V loop shift. It is therefore demonstrated that a VCL not only enhances the FE properties of HZO thin films but also provides a temperature degree of freedom to modulate the FE properties, which may open up a new pathway to develop HfO 2 -based FE memories with high performance and novel functionalities.

Nanoscale phase mixtures in transition-metal oxides (TMOs) often render these materials susceptible to external stimuli (electric field, mechanical stress, etc.), which can lead to rich functional properties and device applications. Here, direct observation and multifield manipulation of a nanoscale mixture of brownmillerite SrFeO 2.5 (BM-SFO) and perovskite SrFeO 3 (PV-SFO) phases in SrFeO x (SFO) epitaxial thin films are reported. The mixed-phase SFO film in its pristine state exhibits a nanoscaffold structure consisting of PV-SFO nanodomains embedded in the BM-SFO matrix. This nanoscaffold structure produces gridlike patterns in the current and electrochemical strain maps, owing to the strikingly different electrical and electrochemical properties of BM-SFO and PV-SFO. Moreover, electric field control of reversible topotactic phase transformation between BM-SFO and PV-SFO is demonstrated by electric-field-induced reversible changes in surface height, conductance, and electrochemical strain response. In addition, it is also shown that the BM-SFO → PV-SFO phase transformation can be enabled by applying mechanical stress. This study therefore not only identifies a strong nanometric structure-property correlation in the mixed-phase SFO but also offers a new paradigm for the multifield control of topotactic phase transformation.

With rapid advances in flexible electronics and communication devices, flexible dielectric capacitors exhibiting high permittivity, low loss, and large electric-field tunability over a wide frequency range have attracted increasing attention. Here, a large-scale Ba 0.67 Sr 0.33 TiO 3 (BST) dielectric thin film sandwiched between SrRuO 3 (SRO) bottom electrode and Pt top electrode is fabricated on a flexible mica substrate. The mica/SRO/BST/Pt capacitor exhibits a dielectric constant (ε r ') of more than 1200, a loss tangent [tan(δ)] as low as 0.16, and a tunability of 67% at low frequencies around 10 kHz. Simultaneously, the capacitor can retain an ε r ' of 540 and a tan(δ) of 0.07 at microwave frequencies, e.g., 18.6 GHz. Moreover, even when the capacitor is bent to a small radius of 5 mm or undergoes 12 000 bending cycles (at 5 mm radius), almost no deterioration in ε r ', tan(δ), and tunability is observed. The excellent dielectricity and mechanical flexibility and durability endow the mica/SRO/BST/Pt capacitor with huge potential for flexible electronic and microwave applications.

Electrically driven magnetic switching (EDMS) is highly demanded for next-generation advanced memories or spintronic devices. The key challenge is to achieve repeatable and reversible EDMS at sufficiently small scale. In this work, we reported an experimental realization of room-temperature, electrically driven, reversible, and robust 120° magnetic state rotation in nanoscale multiferroic heterostructures consisting of a triangular Co nanomagnet array on tetragonal BiFeO 3 films, which can be directly monitored by magnetic force microscope (MFM) imaging. The observed reversible magnetic switching in an individual nanomagnet can be triggered by a small electric pulse within 10 V with an ultrashort time of ∼10 ns, which also demonstrates sufficient switching cycling and months-long retention lifetime. A mechanism based on synergic effects of interfacial strain and exchange coupling plus shape anisotropy was also proposed, which was also verified by micromagnetic simulations. Our results create an avenue to engineer the nanoscale EDMS for low-power-consumption, high-density, nonvolatile magnetoelectric memories and beyond.

For the biosynthesis of Pip in Huperzia serrata, the mechanistic studies were evaluated. Through a series of biochemical analyses, Pip is biosynthesized through a two-step cascade reaction. Three intermediates possibly exist simultaneously as an equilibrium matter in the first-step reaction catalyzed by HsAld1, while HsSard4 performs as a ketimine reductase and chemoselectively and stereoselectively takes 1,2-dehydropipecolic acid as the preferred substrate in vitro.

We report a facile and cost-competitive nanopatterning route, using Ar ion beam etching through a monolayer polystyrene sphere (PS) array placed on a ferroelectric epitaxial thin film, to fabricate ordered ferroelectric nanodot arrays. Using this method, well-ordered BiFeO 3 epitaxial nanodots, with tunable sizes from ∼100 to ∼900 nm in diameter, have been successfully synthesized. Interestingly, a plethora of exotic nanodomain structures, e.g., stripe domains, vortex and antivortex domains, and single domains, are observed in these nanodots. Moreover, this novel technique has been extended to produce Pb(Zr,Ti)O 3 nanodots and multiferroic composite Co/BiFeO 3 nanodots. These observations enable the creation of exotic domain structures and provide a wide range of application potentials for future nanoelectronic devices.

Negative differential resistance (NDR) has been extensively investigated for its wide device applications. However, a major barrier ahead is the low reliability. To address the reliability issues, we consider ferroelectrics and propose an alternative mechanism for realizing the NDR with deterministic current peak positions, in which the NDR results from the polarization switching-induced charge injection and subsequent charge trapping at the metal/ferroelectric interface. In this work, ferroelectric Au/BiFe 0.6 Ga 0.4 O 3 (BFGO)/Ca 0.96 Ce 0.04 MnO 3 (CCMO) nanocapacitors are prepared, and their ferroelectricity and NDR behaviors are studied concurrently. It is observed that the NDR current peaks are located at the vicinity of coercive voltages (V c ) of the ferroelectric nanocapacitors, thus evidencing the proposed mechanism. In addition, the NDR effect is reproducible and robust with good endurance and long retention time. This study therefore demonstrates a ferroelectric-based NDR device, which may facilitate the development of highly reliable NDR devices.