Programmable Nucleation and Growth of Ultrathin Tellurium Nanowires via a Pulsed Physical Vapor Deposition Design

Physical vapor deposition (PVD) methods have been widely employed for high-quality crystal growth and thin-film deposition in semiconductor electronics. However, the fabrication of emerging low dimensional nanostructures is hitherto challenging in conventional PVD systems due to their large thermal mass and near-continuous operation which hinder flexible control of the nucleation and growth events. Herein, a pulsed PVD method is reported that features finely controllable temperature and heating time (down to milliseconds), which enables programming of the vapor supersaturation and decoupling of nucleation and growth events. Take tellurium as an example, the pulsed PVD allows transient source vaporization (≈1000 °C, 30 ms) for burst nucleation, followed by relatively low-temperature volatilization (≈600 °C, 5 min) for steady-state growth with well-suppressed random nucleation. As a result, uniform and high-density tellurium nanowires are obtained at the ultrathin thickness of sub-10 nm and length >10 µm, which is in sharp contrast to the randomly formed nanostructures in conventional PVD. When used in the field-effect transistor, the thin tellurium nanowires display a high on-off ratio of >10⁴ and hole mobility of ≈40 cm² V⁻¹ s⁻¹, showing the potential for high-performance electronics. Pulsed PVD therefore enables to flexibly program and finely tailor the nucleation and growth events during vapor phase deposition, which are otherwise impossible in conventional PVD.     

Fast Li+ Transport via Silica Network-Driven Nanochannels in Ionomer-in-Framework for Lithium Metal Batteries

For the development of all-solid-state lithium metal batteries (LMBs), a high-porous silica aerogel (SA)-reinforced single-Li⁺ conducting nanocomposite polymer electrolyte (NPE) is prepared via two-step selective functionalization. The mesoporous SA is introduced as a mechanical framework for NPE as well as a channel for fast lithium cation migration. Two types of monomers containing weak-binding imide anions and Li⁺ cations are synthesized and used to prepare NPEs, where these monomers are grafted in SA to produce SA-based NPEs (SANPEs) as ionomer-in-framework. This hybrid SANPE exhibits high ionic conductivities (≈10⁻³ S cm⁻¹), high modulus (≈10⁵ Pa), high lithium transference number (0.84), and wide electrochemical window (>4.8 V). The resultant SANPE in the lithium symmetric cell possesses long-term cyclic stability without short-circuiting over 800 h under 0.2 mA cm⁻². Furthermore, the LiFePO₄|SANPE|Li solid-state batteries present a high discharge capacity of 167 mAh g⁻¹ at 0.1 C, good rate capability up to 1 C, wide operating temperatures (from −10 to 40 °C), and a stable cycling performance with 97% capacity retention and 100% coulombic efficiency after 75 cycles at 1 C and 25 °C. The SANPE demonstrates a new design principle for solid-state electrolytes, allowing for a perfect complex between inorganic silica and organic polymer, for high-energy-density LMBs.     

Low-Threshold,External-Cavity-Free Flexible Perovskite Lasers

A distinct advantage of halide perovskite semiconductors is their potential as gain media in high-performance, all-solution-processed flexible lasers. However, most perovskite microlasers employ external optical resonators with rigid and high-temperature/vaccum-processed structures unsuitable for flexible applications. Here, low-threshold, external-cavity-free perovskite lasers (≈550 nm, linewidth: ≈0.3 nm, quality factor: ≈1900, room temperature), prepared with excellent reproducibility using simple one-step spin-coating and low-temperature annealing, are demonstrated. Exceptionally low lasing thresholds of 9.3 and 14.6 µJ cm⁻² are achieved for external-cavity-free perovskite lasers on rigid and flexible substrates, respectively. The thresholds and quality factors are on par with that of high-performance perovskite microlasers with well-designed external cavities. The lasers exhibit good operational stability, showing half-life of >1.8 × 10⁸ pulses under optical pumping in air. Transient optical experiments reveal that the low thresholds stem from enhanced band-to-band spontaneous and stimulated emission processes in the high-quality microcrystalline perovskite, effectively out-pacing trap-mediated and Auger processes detrimental to the lasing action. The flexible perovskite lasers retain >95% of the initial intensity after 10000 bending cycles, showing outstanding mechanical durability. As these lasers can be produced from solution within minutes at low costs, the findings are expected to enable high-throughput, scalable fabrication of perovskite lasers for emerging applications.     

High-Performance Photodetector and Angular-Dependent Random Lasing from Long-Chain Organic Diammonium Sandwiched 2D Hybrid Perovskite Non-Linear Optical Single Crystal

3D organic-inorganic metal halide perovskites are excellent materials for optoelectronic applications due to their exceptional properties, solution processability, and cost-effectiveness. However, the lack of environmental stability highly restricts them from practical applications. Herein, a stable centimeter-long 2D hybrid perovskite (N-MPDA)[PbBr₄] single crystal using divalent N1-methylpropane-1,3-diammonium (N-MPDA) cation as an organic spacer, is reported. The as-grown single crystal exhibits stable optoelectronic performance, low threshold random lasing, and multi-photon luminescence/multi-harmonic generation. A photoconductive device fabricated using (N-MPDA)[PbBr₄] single crystal exhibits an excellent photoresponsivity (≈124 AW⁻¹ at 405 nm) that is ≈4 orders of magnitudes higher than that of monovalent organic spacer-assisted 2D perovskites, such as (BA)₂PbBr₄ and (PEA)₂PbBr₄, and large specific detectivity (≈10¹² Jones). As an optical gain media, the (N-MPDA)[PbBr₄] single crystal exhibits a low threshold random lasing (≈6.5 µJ cm⁻²) with angular dependent narrow linewidth (≈0.1 nm) and high-quality factor (Q ≈ 2673). Based on these results, the outstanding optoelectronic merits of (N-MPDA)[PbBr₄] single crystal will offer a high-performance device and act as a dynamic material to construct stable future electronics and optoelectronic-based applications.     

Photoexcited Ultraviolet-to-Infrared (II) Pyroelectricity in a 2D Ferroelectric Perovskite Driving Broadband Self-Powered Photoactivities

Photoexcited pyroelectricity in ferroelectrics allows the direct conversion of light radiation into electric signal without external power source, thus paving an avenue to promote optoelectronic device performances. However, it is urgently demanded to exploit new ferroelectrics with this attribute covering ultraviolet (UV)-to-infrared (IR) region for self-powered photodetection. Herein, broadband light-induced pyroelectric effects in a new 2D perovskite-type ferroelectric, (BBA)2(EA)2Pb3Br10 (1; BBA = p-bromobenzylammonium, EA = ethylammonium), showing a high Curie temperature of 425 K and notable pyroelectric coefficient (≈5.4 × 10⁻³ µC cm⁻² K⁻¹) is presented. Especially, photo-induced change of its electric polarization leads to ultraviolet-to-infrared pyroelectricity in a wide spectral region (377–1950 nm). Broadband photoactivities actualized by this property break the limitation of its optical bandgap. Thus, single-crystal detectors of 1 are sensitive to UV-to-IR light with a small temperature fluctuation of 0.3 K, exhibiting a high transient responsivity up to ≈0.28 mA W⁻¹ and specific detectivity of 1.31 × 10¹⁰ Jones under zero bias (at 405 nm); such figure-of-merits are beyond than those self-powered photodetectors using oxide ferroelectrics. It is anticipated that the findings of light-induced pyroelectricity afford a feasible strategy to assemble newly-conceptual smart photoelectric devices, such as self-powered broadband detectors.     

Deterministic Polymorphic Engineering of MoTe2 for Photonic and Optoelectronic Applications

Developing selective and coherent polymorphic crystals at the nanoscale offers a novel strategy for designing integrated architectures for photonic and optoelectronic applications such as metasurfaces, optical gratings, photodetectors, and image sensors. Here, a direct optical writing approach is demonstrated to deterministically create polymorphic 2D materials by locally inducing metallic 1T′-MoTe₂ on the semiconducting 2H-MoTe₂ host layer. In the polymorphic-engineered MoTe₂, 2H- and 1T′- crystalline phases exhibit strong optical contrast from near-infrared to telecom-band ranges (1–1.5 µm), due to the change in the band structure and increase in surface roughness. Sevenfold enhancement of third harmonic generation intensity is realized with conversion efficiency (susceptibility) of ≈1.7 × 10⁻⁷ (1.1 × 10⁻¹⁹ m² V⁻²) and ≈1.7 × 10⁻⁸ (0.3 × 10⁻¹⁹ m² V⁻²) for 1T′ and 2H-MoTe₂, respectively at telecom-band ultrafast pump laser. Lastly, based on polymorphic engineering on MoTe₂, a Schottky photodiode with a high photoresponsivity of 90 AW⁻¹ is demonstrated. This study proposes facile polymorphic engineered structures that will greatly benefit realizing integrated photonics and optoelectronic circuits.     

An Ultrafast,High-Loading,and Durable Poly(p-aminoazobenzene)/Reduced Graphene Oxide Composite Electrode for Supercapacitors

Although challenging, the fabricated supercapacitor electrodes with excellent rate capability, long cycling stability, and high mass-loading are crucial for practical applications. Herein, a novel 3D porous poly(p-aminoazobenzene)/reduced graphene oxide hydrogel is designed and prepared as an ultrafast, high-loading, and durable pseudocapacitive electrode through a facile two-step self-assembly approach. Owing to abundant stable redox-active sites, fast electrolyte diffusion, and efficient charge conduction, the PRH electrode (5 mg cm⁻²) shows a high specific capacitance (701 F g⁻¹ at 2 A g⁻¹) and ultrafast rate (97% capacitance retention at 100 A g⁻¹). Furthermore, even with a mass-loading of 10 mg cm⁻², the electrode still exhibits comparable high performance and excellent long-term cycling life (only 6.7% capacitance loss after 10 000 cycles). This work demonstrates novel polyaniline analog composites for constructing novel electrodes, promising to open an avenue toward practical applications.     

Leveraging Bioinspired Structural Constraints for Tunable and Programmable Snapping Dynamics in High-Speed Soft Actuators

Creating high-speed soft actuators will have broad engineering and technological applications. Snapping provides a power-amplified mechanism to achieve rapid movements in soft actuators that typically show slow movements. However, precise control of snapping dynamics (e.g., speed and direction of launching or jumping) remains a daunting challenge. Here, a bioinspired design principle is presented that harnesses a reconfigurable constraint structure integrated into a photoactive liquid crystal elastomer actuator to enable tunable and programmable control over its snapping dynamics. By reconfiguring constrained fin-array-shaped structure, the snapping dynamics of the structured actuator, such as launching or jumping angle and height, motion speed, and release force can be on-demand tuned, thus enabling controllable catapult motion and programmable jumping. Moreover, the structured actuators exhibit a unique combination of ultrafast moving speed (up to 2.5 m s⁻¹ in launching and 0.22 m s⁻¹ in jumping), powerful ejection (long ejection distance of ≈20 cm, 35 mg ball), and high jumping height (≈8 cm, 40 times body lengths), which few other soft actuators can achieve. This study provides a new universal design paradigm for realizing controllable rapid movements and high-power motions in soft matter, which are useful for building high-performance soft robotics and actuation devices.     

Plasmonic Nanoneedle Arrays with Enhanced Hot Electron Photodetection for Near-IR Imaging

Hot electron photodetection based on metallic nanostructures is attracting significant attention due to its potential to overcome the limitation of the traditional semiconductor bandgap. To enable efficient hot electron photodetection for practical applications, it is necessary to achieve broadband and perfect light absorption within extremely thin plasmonic nanostructures using cost-effective fabrication techniques. In this study, an ultrahigh optical absorption (up to 97.3% in average across the spectral range of 1200−2400 nm) is demonstrated in the ultrathin plasmonic nanoneedle arrays (NNs) with thickness of 10 nm, based on an all-wet metal-assisted chemical etching process. The efficient hot electron generation, transport, and injection at the nanoscale apex of the nanoneedles facilitate the photodetector to achieve a record low noise equivalent power (NEP) of 4.4 × 10⁻¹² W Hz^−0.5 at the wavelength of 1300 nm. The hot-electron generation and injection process are elucidated through a transport model based on a Monte Carlo approach, which quantitatively matches the experimental data. The photodetector is further integrated into a light imaging system, as a demonstration of the exceptional imaging capabilities at the near-IR regime. The study presents a lithography-free, scalable, and cost-effective approach to enhance hot electron photodetection, with promising prospects for future imaging systems.     

Electrocatalysis of Fe-N-C Bonds Driving Reliable Interphase and Fast Kinetics for Phosphorus Anode in Sodium-Ion Batteries

Phosphorus exhibits high capacity and low redox potential, making it a promising anode material for future sodium-ion batteries. However, its practical applications are confined by poor durability and sluggish kinetics. Herein, an innovative in-situ electrochemically self-driven strategy is presented to embed phosphorus nanocrystal (≈10 nm) into a Fe-N-C-rich 3D carbon framework (P/Fe-N-C). This strategy enables rapid and high-capacity sodium ion storage. Through a combination of experimental assistance and theoretical calculations, a novel synergistic catalytic mechanism of Fe-N-C is reasonably proposed. In detail, the electrochemical formation of Fe-N-C catalytic sites facilitates the release of fluorine in ester-based electrolyte, inducing Na⁺-conducting-enhanced solid-electrolyte interphase. Furthermore, it also effectively induces the dissociation energy of the P-P bond and promotes the reaction kinetics of P anode. As a result, the unconventional P/Fe-N-C anode demonstrates outstanding rate-capability (267 mAh g⁻¹ at 100 A g⁻¹) and cycling stability (72%, 10 000 cycles). Notably, the assembled pouch cell achieves high-energy density of 220 Wh kg⁻¹.     

Interfacially Super-Assembled Asymmetric and H2O2 Sensitive Multilayer-Sandwich Magnetic Mesoporous Silica Nanomotors for Detecting and Removing Heavy Metal Ions

Asymmetric hollow and magnetic mesoporous silica nanocomposites have great potential applications due to their unique structural–functional properties. Here, asymmetric multilayer-sandwich magnetic mesoporous silica nanobottles (MMSNBs) are presented through an interfacial super-assembly strategy. Asymmetric hollow silica nanobottles (SNBs) are first prepared, and Fe₃O₄ nanoparticles monolayers and mesoporous silica layers are uniformly super-assembled on the surfaces of SNBs, respectively. The high Fe₃O₄ nanoparticles loading endows MMSNBs with a high magnetization (8.5 emu g⁻¹), while the mesoporous silica layers exhibit high surface area (613.4 m² g⁻¹) and large pore size (3.6 nm). MMSNBs can be employed as a novel type of enzyme-powered nanomotors by integrating catalase (Cat-MMSNBs), which show an average speed of 7.59 µm s⁻¹ (≈25 body lengths s⁻¹) at 1.5 wt% H₂O₂. Accordingly, the water quality can be monitored by evaluating the movement speed of Cat-MMSNBs. Moreover, MMSNBs act as a good adsorbent for removing more than 90% of the heavy metal ions with the advantage of the mesoporous structure. In addition, the good magnetic response enables the MMSNBs with precise directional control and is conducive to recycling for repeated operation. This bottom-up interfacial super-assembly construction strategy allows for a new understanding of the rational design and synthesis of multi-functional nanomotors.     

Reconfigurable and Broadband Polarimetric Photodetector

The sensitive detection of light polarization besides the intensity and wavelength, can provide a new degree of freedom for more and clearer information of imaging targets in night, fog, and smoke environment. However, the conventional filter-integrated polarimetric photodetectors suffer from the complicated fabrication process and limited spectral range. Herein, broadband and polarization-sensitive photodetectors are achieved with reconfigurable operation mode, utilizing the linear dichroism and narrow band gap of 2D As_0.4P_0.6 with in-plane anisotropic structure. In As_0.4P_0.6-MoTe₂ heterojunction device, both photo-gating and photovoltaic modes are operated and switchable, contributing to high responsivity (1590 A W⁻¹ at 405 nm and 14.7 A W⁻¹ at 1550 nm) and ultrafast speed (25 µs) in the wide spectral band (405–1550 nm). Interestingly, an optical reversal is observed on both linear dichroism and polarimetric photocurrent due to the wavelength-dependent polarization reverse nature of the As_0.4P_0.6 flakes. The dichroism ratio of photocurrent can be modulated from unity to ≈10 by varying the gate voltage, enabling the reconfigurable detection mode from polarization-independence to polarization-susceptibility. This study demonstrates a new prototype device comprising low symmetric van der Waals heterostructure, possessing the gate-tunability on both photo-gain and dichroism ratio, toward high performance, reconfigurable, broadband, and polarization-resolved photodetection and imaging applications.     

Interface Engineering Enhances the Photovoltaic Performance of Wide Bandgap FAPbBr3 Perovskite for Application in Low-Light Environments

Underwater solar cells (UWSCs) provide an ideal alternative to the energy supply for long-endurance autonomous underwater vehicles. However, different from conventional solar cells situated on land or above water, UWSCs give preference to use wide bandgap semiconductors (≥1.8 eV) as light absorber to match underwater solar spectra. Among wide bandgap semiconductors, FAPbBr₃ perovskite is under prime consideration owing to its matching optical bandgap (≈2.3 eV), outstanding photoelectric properties, easier processability, etc. Unfortunately, for FAPbBr₃ solar cells, substantial interface defects greatly limit the charge carrier extraction efficiency, thus limiting the device performance, especially in underwater low-light environments. This study employs a molecular self-assembly strategy to effectively eliminate the interfacial defects. As a result, a great improvement in power conversion efficiency (PCE) from 6.44% to 7.49% is obtained, which is among the best efficiency reported for inverted FAPbBr₃ solar cells up to date. Besides, a champion PCE of 30% is obtained under 520 nm monochromatic light irradiation (4.8 mW cm⁻²). These results demonstrate that FAPbBr₃ solar cells present a tremendously promising application in UWSCs.     

A Promising Radiation Thermal Protection Coating Based on Lamellar Porous Ca-Cr co-Doped Y3NbO7 Ceramic

Dissipation of heat efficiently from a hot object via radiation while minimizing the inward heat conduction is the key requirement of radiation thermal protection. In this study, a Ca-Cr co-doped Y₃NbO₇ coating with lamellar porous structure is fabricated, which shows an ultra-low thermal conductivity (<0.7 W m⁻¹ K⁻¹) and near-unity emissivity (>0.9) across a broad wavelength range of ≈1–24 µm. This record high emissivity to thermal conductivity ratio (≈1.3) is experimentally and theoretically revealed from a multi-scale perspective. The diffusoin-mediated thermal conduction feature of niobates combined with lamellar porous structure of the coating reduces its thermal conductivity to an impressive 0.5 W m⁻¹ K⁻¹ at 25 °C, surpassing the theoretical amorphous limitation of 0.72 W m⁻¹ K⁻¹. Experiments and FDTD calculation results demonstrate that the intrinsic emissivity dips at shallow extinction wavelengths (1 and 8 µm) and strong phonon-polariton resonances wavelengths (>13 µm) can be effectively compensated by the multiple scattering/absorption and gradual modulation of conical shape/effective refractive index induced by surface micro-protrusion structures, respectively. Furthermore, the coating exhibits robust mechanical and thermal stability with a high bonding strength (18.3 MPa) and thermal expansion coefficient (≈11 × 10⁻⁶ K⁻¹ at 1200 °C) comparable to YSZ, showing great potential in the radiation thermal protection field.     

Indolo[3,2,1-jk]carbazole based planarized CBP derivatives as host materials for PhOLEDs with low efficiency roll-off

Three novel planarized CPB derivatives (ICzCz, ICzPCz, ICzICz) have been synthesized and characterized concerning applications as host materials for PhOLEDs. The incorporation of fully planar indolo[3,2,1-jk]carbazole (ICz) in the CBP scaffold has been systematically investigated, revealing a significant impact on molecular properties, such as improved thermal stability (t_g > 110 °C), high triplet energies (E_T > 2.81 eV) and charge transport properties. Employing the newly developed materials as host materials, efficient green PhOLEDs (CE_max: 60.1 cd A⁻¹, PE_max: 42.1 lm W⁻¹, EQE_max: 15.9%) with a remarkably low efficiency roll-off of 5% at 1000 cd m⁻² as well as blue PhOLEDs (ICzCz) with a high PE of 26.1 lm W⁻¹ have been realized. Hence, the first comprehensive report on the application of ICz as integral building block for electroluminescent materials is presented, establishing this particular structural motive as versatile structural motive in this field.     

Hierarchical Interface Engineering for Advanced Nanocellulosic Hybrid Aerogels with High Compressibility and Multifunctionality

The hierarchical combination of mineral and biopolymer building blocks is advantageous for the notable properties of structural materials. Integrating silane and cellulose nanofibers into high-performance hybrid aerogels is promising yet remains challenging due to the unsatisfied interface connections. Here, an interfacial engineering strategy is introduced via freeze–drying-induced wetting and mineralization to reinforce the hierarchical porous cellulose network, resulting in mineral-coated nanocellulose hybrid aerogels in a simple and consecutive bottom-up assembly process. With optimized multiscale interfacial engineering between the stiff and soft components, the resulting cellulose-based hybrid aerogels are endowed with lightweight (>0.7 mg cm⁻³), superior enhanced mechanical compressibility (>99% strain) within a wide temperature range, as well as super-hydrophobicity (≈168°) and moisture stability under high humidity (95% relative humidity). Benefiting from these superior characters, the multifunctional hybrid aerogels as effective oil/water absorbents with excellent recyclability, thermal insulators in extreme conditions, and sensitive strain sensors are demonstrated. This assembly approach with optimized interfacial features is scalable and efficient, affording high-performance cellulose-based aerogels for various applications.     

An Intrinsically Nonflammable Electrolyte for Prominent-Safety Lithium Metal Batteries with High Energy Density and Cycling Stability

Nex-generation high-energy-density storage battery, assembled with lithium (Li)-metal anode and nickel-rich cathode, puts forward urgent demand for advanced electrolytes that simultaneously possess high security, wide electrochemical window, and good compatibility with electrode materials. Herein an intrinsically nonflammable electrolyte is designed by using 1 M lithium difluoro(oxalato)borate (LiDFOB) in triethyl phosphate (TEP) and N-methyl-N-propyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide [Pyr₁₃][TFSI] ionic liquid (IL) solvents. The introduction of IL can bring plentiful organic cations and anions, which provides a cation shielding effect and regulates the Li⁺ solvation structure with plentiful Li⁺-DFOB⁻ and Li⁺-TFSI⁻ complexes. The unique Li⁺ solvation structure can induce stable anion-derived electrolyte/electrode interphases, which effectively inhibit Li dendrite growth and suppress side reactions between TEP and electrodes. Therefore, the LiNi_0.9Co_0.05Mn_0.05O₂ (NCM90)/Li coin cell with this electrolyte can deliver stable cycling even under 4.5 V and 60 °C. Moreover, a Li-metal battery with thick NCM90 cathode (≈ 15 mg cm⁻²) and thin Li-metal anode (≈ 50 µm) (N/P ≈ 3), also reveals stable cycling performance under 4.4 V. And a 2.2 Ah NCM90/Li pouch cell can simultaneously possess prominent safety with stably passing the nail penetration test, and high gravimetric energy density of 470 Wh kg⁻¹ at 4.4 V.     

Dynamically Tunable Subambient Daytime Radiative Cooling Metafabric with Janus Wettability

Incorporating zero-energy-input cooling technology into personal thermal management (PTM) systems is a promising solution for preventing heat-related illnesses while reducing energy consumption. Although concepts for passive radiative cooling materials are proposed, achieving subambient cooling performance while providing good wearing comfort remains a challenge. Here, a moisture-wicking nonwoven metafabric is reported that assembles radiative cooling and evaporative heat dissipation to achieve high-performance thermal and moisture comfort management. This metafabric demonstrates excellent spectral-selectivity (sunlight reflection of ≈92%, atmospheric window thermal emissivity of ≈97%) and Janus wettability through large-scale electrospinning and hierarchical design, and also inherits superior elasticity, air/moisture permeability of nonwoven fabric. Subambient temperature drops of ≈6.5 °C (≈750 W m⁻² solar intensity) for stand-alone metafabric are observed. Thanks to the moisture-wicking effect (water evaporation rate of 0.31 g h⁻¹ and water transport index of 1220%) of metafabric that enables fast evaporation of sweat, a maximum generation of 1 mL h⁻¹ of sweat can cool the skin, thus reducing the excessive sweating risk after intense exercise. Additionally, the cooling performance of metafabric can be regulated by applying various strains (0–100%). The cost-efficiency and good wearability of metafabric provide an innovative way to sustainable energy, smart textiles, and thermal wet comfort applications.     

Al2O3/TiO2 nanolaminate gate dielectric films with enhanced electrical performances for organic field-effect transistors

Nanolamination has entered the spotlight as a novel process for fabricating highly dense nanoscale inorganic alloy films. OFET commercialization requires, above all, excellent dielectric properties of gate dielectric layer. Here, we describe the fabrication and characterization of Al–O–Ti (AT) nanolaminate gate dielectric films using a PEALD process, and their OFET applications. The AT films exhibited a very smooth surface (R_q < 0.3 nm), a high dielectric constant (17.8), and a low leakage current (8.6 × 10⁻⁹ A/cm² at 2 MV/cm) compared to single Al₂O₃ or TiO₂ films. Importantly, a 50 nm thick AT film dramatically enhanced the value of μFET (0.96 cm²/V) on a pentacene device, and the high off-current level in a single TiO₂ film was effectively reduced. The nanolamination process removes the drawbacks inherent in each single layer so that the AT film provides excellent dielectric properties suitable for fabricating high-performance OFETs. Triethylsilylethynyl anthradithiophene (TES-ADT), a solution-processable semiconductor, was combined with the AT film in an OFET, and the electrical properties of the device were characterized. The excellent dielectric properties of the AT film render nanolamination a powerful strategy for practical OFET applications.     

Optimized Ti?O Subcompounds and Elastic Expanded MXene Interlayers Boost Quick Sodium Storage Performance

To develop quick-charge sodium-ion battery, it is significant to optimize insertion-type anode to afford fast Na⁺ diffusion rate and excellent electron conductivity. First-principles calculations reveal the Ti O subcompound superiority for Na⁺ diffusion following Ti(II) O > Ti(III) O > Ti(IV) O. Hence, in situ growth of amorphous Ti O subcompounds with rich oxygen defects based on Ti₃C₂T_x-MXene is developed. Meanwhile, the composite presents expanded MXene interlayer spacing and much enhanced conductivity. The synergistic effect of enhanced electron/ion conduction gives a high capacity of 107 mAh g⁻¹ at 50 A g⁻¹, which gives 50% and 150% increasements compared with one counterpart without valence adjustment and another one without MXene expansion. It only needs 20 s (at 30 A g⁻¹) to complete the discharge/charge process and obtains a capacity of 144.5 mAh g⁻¹, which also shows a long-term cycling stability at quick-charge mode (121 mAh g⁻¹ after 10000 cycles at 10 A g⁻¹). The enhanced performance comes from fast electron transfer among Ti O subcompounds contributed by rich-defect amorphous TiO_2–x, and a reversible change of elastic MXene with interlayer spacing between 1.4 and 1.9 nm during Na⁺ insertion/extraction process. This study provides a feasible route to boost the kinetics and develop quick-charge sodium-ion battery.