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van der Waals (vdWs) dielectrics are widely used in nanoelectronics to preserve the intrinsic properties of two-dimensional (2D) semiconductors. However, achieving aligned growth of 2D semiconductors and their direct utilization on original vdWs epitaxial dielectrics to avoid disorders poses significant challenges. Here, a hydromechanical strategy for aligned epitaxy of 2D materials on naturally occurring vdWs mica dielectrics is developed. By combining density functional theory with Lagrange’s group theorem, a quantitative criterion for 2D material epitaxy on 6-fold symmetric vdWs dielectrics is established. Moreover, the as-grown ultrathin Bi2O2Se-channeled field-effect transistor, with a hybrid dielectric layer, achieves a superior current on/off ratio (1.4 × 107) and high carrier mobility (22.4 cm2V−1S−1) by directly integrating as-grown 2D materials/vdWs dielectrics. This work provides a powerful methodological platform for aligned 2D material synthesis, alignment direction prediction, and intrinsic property investigation, laying the foundation for advanced electronics on as-grown 2D materials/vdWs dielectrics.

Benign and malignant classification of clustered microcalcifications (MCs) in digital breast tomosynthesis (DBT) is an essential task in computer-aided diagnosis. However, due to the anisotropic resolution of DBT, three-dimensional (3-D) convolutional neural network (CNN)-based methods cannot extract hierarchical features efficiently. Moreover, the sparse distribution of MC points in the cluster makes it difficult for the CNN to extract discriminative structural information for classification. To comprehensively address these challenges, we propose a novel structure-aware hierarchical network (SAH-Net) for benign and malignant classification of clustered MC in a DBT volume. Specifically, the two-dimensional (2-D) group convolution is used to extract intraslice features. The one-to-one correspondence between group convolutions and slices ensures the independence of hierarchical feature extraction. Then, a partial deformable Transformer-based 3-D structural feature learning module is proposed to capture the long-range dependency between MC points in the cluster. We evaluate the proposed method on an in-house dataset with 495 clustered MCs collected from 462 DBT images. Experimental results confirm the validity of our proposed modules. The results also show that the proposed SAH-Net outperforms several other representative methods on this topic, and achieves the best classification result, with an area under the receiver operation curve (AUC) of 86.87%. The implementation of the proposed model is available at https://github.com/sunhaotian130911/SAHNet.

All-inorganic lead halide perovskites (CsPbX3, X = Cl, Br or I) are becoming increasingly important for energy conversion and optoelectronics because of their outstanding performance and enhanced environmental stability. Morphing perovskites into specific shapes and geometries without damaging their intrinsic functional properties is attractive for designing devices and manufacturing. However, inorganic semiconductors are often intrinsically brittle at room temperature, except for some recently reported layered or van der Waals semiconductors. Here, by in situ compression, we demonstrate that single-crystal CsPbX3micropillars can be substantially morphed into distinct shapes (cubic, L and Z shapes, rectangular arches and so on) without localized cleavage or cracks. Such exceptional plasticity is enabled by successive slips of partial dislocations on multiple {110}⟨11¯0⟩systems, as evidenced by atomic-resolution transmission electron microscopy and first-principles and atomistic simulations. The optoelectronic performance and bandgap of the devices were unchanged. Thus, our results suggest that CsPbX3perovskites, as potential deformable inorganic semiconductors, may have profound implications for the manufacture of advanced optoelectronics and energy systems.

Organic-inorganic halide perovskite, as a low-cost, solution-processable material with remarkable optoelectronic properties, is ideal candidate to fabricate high-performance photodetectors and is expected to significantly reduce device costs. Compared to the common Dion-Jacobson and Ruddlesden-Popper two-dimensional (2D) layered hybrid perovskite compounds, the perovskites with alternating cations in the interlayer (ACI) phase show higher crystal symmetry and narrower optical bandgaps, which exhibit great potential for excellent photodetection performance. Herein, we report a high-performance photodetector based on the 2D bilayered hybrid lead halide perovskite single crystal with the ACI phase (GAMA2Pb2I7; GA = C(NH2)3and MA = CH3NH3). The single-crystal photodetector exhibits high photoresponsivity of 1.56, 2.54, and 2.60 A/W for incident light wavelengths of 405, 532, and 635 nm under 9.82 nW, respectively, together with the correspondingly high detectivity values of 1.86 × 1012, 3.04 × 1012, and 3.11 × 1012Jones under the same operating conditions. Meanwhile, a high-resolution imaging sensor is built based on the GAMA2Pb2I7single-crystal photodetector, confirming the high stability and photosensitivity of the imaging system. These results show that the 2D hybrid lead halide perovskites with alternating interlayer cations are promising for high-performance visible light photodetectors and imaging systems.

Converting vapor precursors to solid nanostructures via a liquid noble-metal seed is a common vapor deposition principle. However, such a noble-metal-seeded process is excluded from the crystalline halide perovskite synthesis, mainly hindered by the growth mechanism shortness. Herein, powered by a spontaneous exothermic nucleation process (ΔH< 0), the Au-seeded CsPbI3nanowires (NWs) growth is realized based on a vapor–liquid–solid (VLS) growth mode. It is energetically favored that the Au seeds are reacted with a Pb vapor precursor to form molten Au–Pb droplets at temperatures down to 212 °C, further triggering the low-temperature VLS growth of CsPbI3NWs. More importantly, this Au-seeded process reduces in-bandgap trap states and consequently avoids Shockley–Read–Hall recombination, contributing to outstanding photodetector performances. Our work extends the powerful Au-seeded VLS growth mode to the emerging halide perovskites, which will facilitate their nanostructures with tailored material properties.

Competing hydrogen evolution reaction (HER) and sluggish multi-electron/proton-involved steps are the major obstacles to improving the efficiency and selectivity of electrochemical nitrate reduction to ammonia (eNO3RR). Herein, we modified Co3O4nanoparticles with doped rare-earth La atoms and carboxylic (COO−)-based organic ligands. The COO−groups efficiently reduce the water activity around the active sites by forming hydrogen bonds, thus controlling proton accessibility and regulating the adsorption selectivity between nitrate ions and protons. Simultaneously, introducing oxygen vacancies through La doping establishes active sites with a strong affinity for nitrate ions and an electron-rich local environment conducive to eNO3RR. The electrocatalyst exhibits superior activity and selectivity with an ammonia Faradaic efficiency of up to 99.41% and a yield rate of 5.62 mg h−1mgcat−1at −0.3 V vs. reversible hydrogen electrode (RHE). Notably, the catalyst maintains over 90% Faradaic efficiency for NH3production across a broad potential range of 400 mV, surpassing most recently reported eNO3RR electrocatalysts.

Due to the better stability and environment-friendly nature, lead-free halide double perovskites are widely explored as promising materials for next-generation photovoltaics and optoelectronics; however, to date, their photoelectric device performance is still not satisfactory. Herein, we report a facile solution-process method to synthesize the recently most popular lead-free halide double perovskite, MA2AgBiBr6, and its all-inorganic counterpart, Cs2AgBiBr6. The obtained MA2AgBiBr6and Cs2AgBiBr6films exhibit the microplatelet morphology with excellent crystallinity, distinctly contrasting the ones fabricated by the conventional spin-coating method. Once fabricated into simple photodetectors, the Cs2AgBiBr6microplatelet devices yield a respectable responsivity of 245 mA W−1that is two orders of magnitude larger than that of the spin-coated films. More importantly, the response speed of the Cs2AgBiBr6microplatelets device is as fast as 145 µs, which is higher than most of the values reported in the community of halide double perovskites. When subjected to the thermal stability testing, the Cs2AgBiBr6microplatelet device can maintain its initial performance after heating to 160°C and cooling down to room temperature in the ambient environment. All these results suggest that the facile solution-process method is capable of fabricating high-quality lead-free double perovskites, enabling their advanced device applications.

Because of the excellent electrical properties, III–V semiconductor nanowires are promising building blocks for next-generation electronics; however, their rich surface states inevitably contribute large amounts of charge traps, leading to gate bias stress instability and hysteresis characteristics in nanowire field-effect transistors (FETs). Here, we investigated thoroughly the gate bias stress and hysteresis effects in InAs nanowire FETs. It is observed that the output current decreases together with the threshold voltage shifting to the positive direction when a positive gate bias stress is applied, and vice versa for the negative gate bias stress. For double-sweep transfer characteristics, the significant hysteresis behavior is observed, depending heavily on the sweeping rate and range. On the basis of complementary investigations of these devices, charge traps are confirmed to be the dominant factor for these instability effects. Importantly, the hysteresis can be simulated well by utilizing a combination of the rate equation for electron density and the empirical model for electron mobility. This provides an accurate evaluation of carrier mobility, which is in distinct contrast to the overestimation of mobility when using the transconductance for calculation. All these findings are important for understanding the charge trap dynamics to further enhance the device performance of nanowire FETs.

While halide perovskite electronics are rapidly developing, they are greatly limited by the inferior charge transport and poor stability. In this work, effective surface charge transfer doping of vapor–liquid–solid (VLS)-grown single-crystalline cesium lead bromide perovskite (CsPbBr3) nanowires (NWs) viamolybdenum trioxide (MoO3) surface functionalization is achieved. Once fabricated into NW devices, due to the efficient interfacial charge transfer and reduced impurity scattering, a 15× increase in the field-effect hole mobility (μh) from 1.5 to 23.3 cm2/(V s) is accomplished after depositing the 10 nm thick MoO3shell. This enhanced mobility is already better than any mobility value reported for perovskite field-effect transistors (FETs) to date. The photodetection performance of these CsPbBr3/MoO3core–shell NWs is also investigated to yield a superior responsivity (R) up to 2.36 × 103A/W and an external quantum efficiency (EQE) of over 5.48 × 105% toward the 532 nm regime. Importantly, the MoO3shell can provide excellent surface passivation to the CsPbBr3NW core that minimizes the diffusion of detrimental water and oxygen molecules, improving the air stability of CsPbBr3/MoO3core–shell NW devices. All these findings evidently demonstrate the surface doping as an enabling technology to realize high-mobility and air-stable low-dimensional halide perovskite devices.

Quasi-2D halide perovskites, especially the Ruddlesden–Popper perovskites (RPPs), have attracted great attention because of their promising properties for optoelectronics; however, there are still serious drawbacks, such as inefficient charge transport, poor stability, and unsatisfactory mechanical flexibility, restricting further utilization in advanced technologies. Herein, high-quality quasi-2D halide perovskite thin films are successfully synthesized with the introduction of the unique bication ethylenediammonium (EDA) via a one-step spin-coating method. This bication EDA, with short alkyl chain length, can not only substitute the typically bulky and weakly van der Waals-interacted organic bilayer spacer cations forming the novel Dion–Jacobson phase to enhance the mechanical flexibility of the quasi-2D perovskite (e.g., EDA(MA)n−1PbnI3n+1; MA = CH3NH3+) but also serve as a normal cation to achieve the more intact films (e.g., (iBA)2(MA)3–2x(EDA)xPb4I13). When fabricated into photodetectors, these optimized EDA-based perovskites deliver an excellent responsivity of 125 mA/W and a fast response time down to 380 μs under 532 nm irradiation. More importantly, the device with the Dion–Jacobson phase perovskite can be bent down to a radius of 2 mm and processed with 10,000 cycles of the bending test without any noticeable performance degradation because of its superior structure to RPPs. Besides, these films do not exhibit any material deterioration after ambient storage for 30 days. All these performance parameters are already comparable or even better than those of the state-of-the-art RPPs recently reported. This work provides valuable design guidelines of the quasi-2D perovskites to obtain high-performance flexible photodetectors for next-generation optoelectronics.

Sinomenine (SN) has been used in the clinical treatment of systemic lupus erythematosus and rheumatoid arthritis for many years. Studies showed that SN held protective effects such as anti-inflammation, scavenging free radicals and suppressing immune response in many autoimmune diseases. The purpose of the present study is to explore the mechanism of anti-inflammation of SN on lipopolysaccharide (LPS)-induced macrophages activation and investigate whether the TLR4/NF-κB signaling pathway participated in. Macrophages isolated from mouse peritoneal cavity were stimulated by 1 µg/mL LPS for 24 h. And then the cells were treated with various concentrations of SN, TLR4 inhibitor respectively for additional 48 h. Drug toxicity was detected by MTT assay and Transwell experiment was used to assess chemotaxis. Furthermore, TLR4 and MyD88 mRNA levels were detected by real-time PCR. Western blotting was used to examine TLR4, MyD88 and phosphorylated IκB protein expression in macrophages. Immunofluorescence assay was applied to observe p65 NF-κB protein expression in macrophage nucleus. We extracted macrophages with high purity and activity from the abdominal cavity of mice. SN remarkably inhibited the chemotaxis and secretion function of LPS-stimulated macrophages. It also down-regulated both the protein levels of inflammatory cytokines (TNF-α, IL-1β and IL-6) and the RNA and protein levels of the key factors (TLR4, MyD88, P-IκB) in TLR4 pathway. The expression of p65 NF-κB protein in nuclei was down-regulated, which was correlated with a similar decrease in P-IκB protein level. In conclusion, SN can inhibit the LPS induced immune responses in macrophages by blocking the activated TLR4/NF-κB signaling pathway. These results may provide a therapeutic approach to regulate inflammatory responses.

Composition-adjustable semiconductor nanomaterials have garnered significant attention due to their controllable bandgaps and electronic structures, providing alternative opportunities to regulate photoelectric properties and develop the corresponding multifunction optoelectronic devices. Nevertheless, the large-scale integration of semiconductor nanomaterials into practical devices remains challenging. Here, we report a synthesis strategy for the well-aligned horizontal CdSxSe1–x(x= 0–1) nanowall arrays, which are guided grown on an annealed M-plane sapphire using chemical vapor deposition (CVD) approaches. Microstructural characterizations demonstrate these structures as horizontally guided nanowalls with high-quality crystallinity. Microphotoluminescence (μ-PL) reveals the CdSxSe1–xnanowalls exhibiting continuously tunable spontaneous emissions from 509 nm (pure CdS) to 713 nm (pure CdSe), further confirming that CdSxSe1–xalloys have a continuously tunable bandgap. Notably, a photodetector based on CdSxSe1–xnanowalls displays excellent photoelectric performance, such as high responsivity (3 × 102∼ 1 × 103A/W), high external quantum efficiency (1.01 × 103∼ 2.93 × 103), and fast response speed in the millisecond magnitude. Furthermore, the CdS nanowall-based photodetectors exhibit a remarkable image-sensing capability, indicating potential applications in high-performance image sensing in the future. Bandgap continuously tunable nanowall arrays with high-quality crystallinity inject great vitality into the manufacturing of high-performance integrated optoelectronic devices.

This study presents the development of a radical enantioselective alkene oxysulfonylation approach for the synthesis of enantioenriched sulfonyl phthalides via a catalyst system consisting of a copper salt and an OPPA ligand. The reaction proceeded under mild conditions with a wide range of substrates, good yields, and excellent enantioselectivities. Mechanistic studies suggested that the reaction proceeded through a radical-mediated process. Scalable synthesis and transformation experiments also demonstrated the applicable potential of this method.

Precise synthesis of all-inorganic lead halide perovskite nanowire heterostructures and superlattices with designable modulation of chemical compositions is essential for tailoring their optoelectronic properties. Nevertheless, controllable synthesis of perovskite nanostructure heterostructures remains challenging and underexplored to date. Here, we report a rational strategy for wafer-scale synthesis of one-dimensional periodic CsPbCl3/CsPbI3superlattices. We show that the highly parallel array of halide perovskite nanowires can be prepared roughly as horizontally guided growth on an M-plane sapphire. A periodic patterning of the sapphire substrate enables position-selective ion exchange to obtain highly periodic CsPbCl3/CsPbI3nanowire superlattices. This patterning is further confirmed by micro-photoluminescence investigations, which show that two separate band-edge emission peaks appear at the interface of a CsPbCl3/CsPbI3heterojunction. Additionally, compared with the pure CsPbCl3nanowires, photodetectors fabricated using these periodic heterostructure nanowires exhibit superior photoelectric performance, namely, high ION/IOFFratio (104), higher responsivity (49 A/W), and higher detectivity (1.51 × 1013Jones). Moreover, a spatially resolved visible image sensor based on periodic nanowire superlattices is demonstrated with good imaging capability, suggesting promising application prospects in future photoelectronic imaging systems. All these results based on the periodic CsPbCl3/CsPbI3nanowire superlattices provides an attractive material platform for integrated perovskite devices and circuits.

Time-resolved or time-correlation measurements using cathodoluminescence (CL) reveal the electronic and optical properties of semiconductors, such as their carrier lifetimes, at the nanoscale. However, halide perovskites, which are promising optoelectronic materials, exhibit significantly different decay dynamics in their CL and photoluminescence (PL). We conducted time-correlation CL measurements of CsPbBr3using Hanbury Brown-Twiss interferometry and compared them with time-resolved PL. The measured CL decay time was on the order of subnanoseconds and was faster than PL decay at an excited carrier density of 2.1 × 1018cm–3. Our experiment and analytical model revealed the CL dynamics induced by individual electron incidences, which are characterized by highly localized carrier generation followed by a rapid decrease in carrier density due to diffusion. This carrier diffusion can play a dominant role in the CL decay time for undoped semiconductors, in general, when the diffusion dynamics are faster than the carrier recombination.

Despite the recent advances in electrochemical water splitting, developing cost-effective and highly efficient electrocatalysts for oxygen evolution reaction (OER) still remains a substantial challenge. Herein, two-dimensional cobalt phosphate hydroxides (Co5(PO4)2(OH)4) nanosheets, a unique stacking-disordered phosphate-based inorganic material, are successfully prepared via a facile and scalable method for the first time to serve as a superior and robust electrocatalyst for water oxidation. On the basis of the detailed characterization (e.g., X-ray absorption near-edge structure and X-ray photoelectron spectroscopy), the obtained nanosheets consist of special zigzag CoO6octahedral chains along with intrinsic lattice distortion and excellent hydrophilicity, in which these factors contribute to the highly efficient performance of prepared electrocatalysts for OER. Specifically, Co5(PO4)2(OH)4deposited on glassy carbon electrode (loading amount ≈0.553 mg cm–2) can exhibit an unprecedented overpotential of 254 mV to drive a current density of 10 mA cm–2with a small Tafel slope of 57 mV dec–1in alkaline electrolytes, which outperforms the ones of CO3(PO4)2(370 mV) and Co(OH)2(360 mV) as well as other advanced catalysts. Evidently, this work has opened a new pathway to the rational design of promising metal phosphate hydroxides toward the efficient electrochemical energy conversion.

Due to the efficient photocarrier separation and collection coming from their distinctive band structures, superlattice nanowires (NWs) have great potential as active materials for high-performance optoelectronic devices. In this work, InGaZnO NWs with superlattice structure and controllable stoichiometry are obtained by ambient-pressure chemical vapor deposition. Along the NW axial direction, perfect alternately stacking of InGaO(ZnO)4+blocks and InO2–layers is observed to form a periodic layered structure. Strikingly, when configured into individual NW photodetectors, the Ga concentration is found to significantly influence the amount of oxygen vacancies and oxygen molecules adsorbed on the NW surface, which dictate the photoconducting properties of the NW channels. Based on the optimized Ga concentration (i.e., In1.8Ga1.8Zn2.4O7), the individual NW device exhibits an excellent responsivity of 1.95 × 105A/W and external quantum efficiency of as high as 9.28 × 107% together with a rise time of 0.93 s and a decay time of 0.2 s for the ultraviolet (UV) photodetection. Besides, the obtained NWs can be fabricated into large-scale parallel arrays on glass substrates as well to achieve fully transparent UV photodetectors, where the performance is on the same level or even better than many transparent photodetectors with high performance. All the results discussed above demonstrate the great potential of InGaZnO superlattice NWs for next-generation advanced optoelectronic devices.

Because of their fascinating properties, two-dimensional (2D) nanomaterials have attracted a lot of attention for developing next-generation electronics and optoelectronics. However, there is still a lack of cost-effective, highly reproducible, and controllable synthesis methods for developing high-quality semiconducting 2D monolayers with a sufficiently large single-domain size. Here, utilizing a NaOH promoter and W foils as the W source, we have successfully achieved the fabrication of ultralarge single-domain monolayer WS2films via a modified chemical vapor deposition method. With the proper introduction of a NaOH promoter, the single-domain size of monolayer WS2can be increased to 550 μm, while the WS2flakes can be well controlled by simply varying the growth duration and oxygen concentration in the carrier gas. Importantly, when they are fabricated into global backgated transistors, WS2devices exhibit respectable peak electron mobility up to 1.21 cm2V–1s–1, which is comparable to those of many state-of-the-art WS2transistors. Photodetectors based on these single-domain WS2monolayers give an impressive photodetection performance with a maximum responsivity of 3.2 mA W–1. All these findings do not only provide a cost-effective platform for the synthesis of high-quality large single-domain 2D nanomaterials, but also facilitate their excellent intrinsic material properties for the next-generation electronic and optoelectronic devices.

Group III oxides, such as In2O3and Ga2O3, have proved to be good candidates as active materials for novel electronic devices, including high-mobility transistors, gas sensors, and UV photodetectors. The ability to tune optical and electronic properties is provided by alloying In2xGa2–2xO3(InGaO) in a broad compositional range. Further development of InGaO compounds in the form of nanowires (NWs) would overcome the technological limitations, such as the substrate crystal lattice mismatch and the inability to fabricate high quality structures above the critical thickness. In this work, optical properties of alloyed InGaO NWs in a wide compositional range are carefully assessed. Unlike classical optical characterization methods, photoacoustic spectroscopy reveals the fundamental absorption edge despite the strong light scattering in porous and randomly oriented nanowires structure. An unusual compositional band gap dependence is also observed, giving insight into the phase segregation effect and increased quality of mixed NWs. In addition, photoacoustic measurements disclose potential applications of InGaO NWs in remote, light-driven loudspeakers because of intense photoacoustic effect in nanowire ensembles in this material system.

Controlled synthesis of lead halide perovskite (LHP) nanostructures not only benefits fundamental research but also offers promise for applications. Among many synthesis techniques, although catalytic vapor–liquid–solid (VLS) growth is recognized as an effective route to achieve high-quality nanostructures, until now, there is no detailed report on VLS grown LHP nanomaterials due to the emerging challenges in perovskite synthesis. Here, we develop a direct VLS growth for single-crystalline all-inorganic lead halide perovskite (i.e., CsPbX3; X = Cl, Br, or I) nanowires (NWs). These NWs exhibit high-performance photodetection with the responsivity exceeding 4489 A/W and detectivity over 7.9 × 1012Jones toward the visible light regime. Field-effect transistors (FET) based on individual CsPbX3NWs are also fabricated, where they show the superior hole mobility of up to 3.05 cm2/(V s), higher than other all-inorganic LHP devices. This work provides important guidelines for the further improvement of these perovskite nanostructures for utilizations.

One-dimensional metal-oxide nanowires are regarded as important building blocks in nanoscale electronics, because of their unique mechanical and electrical properties. In this work, p-type nickel oxide nanowires (NiO NWs) were fabricated by combining sol–gel and electrospinning processes. The poly(vinylpyrrolidone) (PVP) with a molecular weight of 1 300 000 was used as the polymer matrix to increase the viscosity of a NiO precursor solution. The formation and properties of the as-spun NiO/PVP composite NWs before/after calcination treatment were investigated using various techniques. Because of the enhanced adhesion properties between ultraviolet (UV)-treated NiO NWs and the substrate, the field-effect transistors (FETs) based on NiO NWs were found to exhibit satisfying p-channel behaviors. For the fabrication of aligned NiO NW arrays, two parallel conducting Si strips were grounded as NW collector. The integrated FETs based on aligned NiO NWs were demonstrated to exhibit superior electrical performance, compared to the disordered counterparts with the comparable NW coverage. By employing high-kaluminum oxide (Al2O3) as a dielectric layer, instead of conventional SiO2, the devices with an aligned NiO NW array exhibit a high hole mobility of 2.8 cm2/(V s) with a low operating voltage of 5 V, fast switching speed, and successful modulation of light emission over external light-emitting diodes. To the best of our knowledge, this is the first work demonstrating the low-voltage transistors based on p-type oxide NWs, which represents a great step toward the development of sensors and CMOS logic circuits.

Recently, semiconducting nanofiber networks (NFNs) have been considered as one of the most promising platforms for large-area and low-cost electronics applications. However, the high contact resistance among stacking nanofibers remained to be a major challenge, leading to poor device performance and parasitic energy consumption. In this report, a controllable welding technique for NFNs was successfully demonstrated via a bioinspired capillary-driven process. The interfiber connections were well-achieved via a cooperative concept, combining localized capillary condensation and curvature-induced surface diffusion. With the improvements of the interfiber connections, the welded NFNs exhibited enhanced mechanical property and high electrical performance. The field-effect transistors (FETs) based on the welded Hf-doped In2O3(InHfO) NFNs were demonstrated for the first time. Meanwhile, the mechanisms involved in the grain-boundary modulation for polycrystalline metal-oxide nanofibers were discussed. When the high-k ZrOxdielectric thin films were integrated into the FETs, the field-effect mobility and operating voltage were further improved to be 25 cm2V–1s–1and 3 V, respectively. This is one of the best device performances among the reported nanofibers-based FETs. These results demonstrated the potencies of the capillary-driven welding process and grain-boundary modulation mechanism for metal-oxide NFNs, which could be applicable for high-performance, large-scale, and low-power functional electronics.

Technical development for thin-film fabrication is essential for emerging metal-oxide (MO) electronics. Although impressive progress has been achieved in fabricating MO thin films, the challenges still remain. Here, we report a versatile and general thermal-induced nanomelting technique for fabricating MO thin films from the fiber networks, briefly called fiber-to-film (FTF) process. The high quality of the FTF-processed MO thin films was confirmed by various investigations. The FTF process is generally applicable to numerous technologically relevant MO thin films, including semiconducting thin films (e.g., In2O3, InZnO, and InZrZnO), conducting thin films (e.g., InSnO), and insulating thin films (e.g., AlOx). By optimizing the fabrication process, In2O3/AlOxthin-film transistors (TFTs) were successfully integrated by fully FTF processes. High-performance TFT was achieved with an average mobility of ∼25 cm2/(Vs), an on/off current ratio of ∼107, a threshold voltage of ∼1 V, and a device yield of 100%. As a proof of concept, one-transistor-driven pixel circuit was constructed, which exhibited high controllability over the light-emitting diodes. Logic gates based on fully FTF-processed In2O3/AlOxTFTs were further realized, which exhibited good dynamic logic responses and voltage amplification by a factor of ∼4. The FTF technique presented here offers great potential in large-area and low-cost manufacturing for flexible oxide electronics.

Electrospun metal oxide nanofibers have been regarded as promising blocks for large-area, low-cost, and one-dimensional electronic devices. However, the electronic devices based on electrospun nanofibers usually suffer from poor performance and inferior viability. Here, we report an efficient photochemical process using UV light generated by a high-pressure mercury lamp to promote the electrical performance of the nanofiber-based electronic devices. Such UV treatment can lead to strong photochemical activation of electrospun nanofibers, and therefore, a stable adherent nanofiber network and electronic-clean interface were formed. By use of UV treatment, high-performance indium oxide (In2O3) nanofiber based field-effect transistors (FETs) with highly efficient modulation of electrical characteristics have been successfully fabricated. To reduce the operating voltage and further improve the device performance, the In2O3nanofiber FETs based on solution-processed high-k AlOxdielectrics were integrated and investigated. The as-fabricated In2O3/AlOxFETs exhibit superior electrical performance, including a high mobility of 19.8 cm2V–1s–1, a large on/off current ratio of 106, and high stability over time and cycling. The improved performance of the UV-treated FETs was further confirmed by the integration of the electrospun In2O3/AlOxFETs into inverters. This work presents an important advance toward the practical applications of electrospun nanofibers for functional electronic devices.

Rational design of bifunctional two-dimensional (2D) heterostructures with excellent activity and durability remains a great challenge for electrocatalytic water splitting. Herein, we propose a topochemical domain engineering to realize 2D mosaic heterostructures with ultrafine phosphide nanodomains highly dispersed on the surface of Ru doped CoMoO4nanosheets (denoted as Ru-CMOP), which are vertically interconnected on the conductive skeleton assembling a 3D array structure. The as-prepared Ru-CMOP electrocatalyst exhibits excellent activity and long-term stability with the overpotentials of 114 and 286 mV at 100 mA cm−2for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1.0 M KOH solution, respectively, outperforming most reported metal phosphide-based bifunctional heterostructures. Moreover, an assembled electrolyzer using the Ru-CMOP as anode and cathode simultaneously delivers cell voltages of 1.697 V and 1.828 V to achieve 100 mA cm−2and 500 mA cm−2, respectively, with outstanding durability at 250 mA cm−2for 120 h. Density functional theory calculations and experimental results indicate that the strongly coupled heterointerfaces with built-in electric field can facilitate electron transfer while multi-porous nanosheet arrays contribute to active sites exposure and mass/gas transport, thereby synergistically accelerating the reaction kinetics. Additionally, combining with a commercial silicon photovoltaic solar cell, the electrolyzer can be efficiently and robustly established, demonstrating the great potential for practical photovoltaic-electrolysis applications.