The deterministic fabrication of silicon vacancy centers with localized precision and well-defined lattice orientation is a critical prerequisite for enabling quantum applications of color centers and for advancing integrated quantum technologies. In 4H-SiC, silicon vacancies can exist in two distinct orientations due to the symmetry of the lattice environment, V1 and V2; however, targeted positioning and preferential creation of these orientations have been rarely explored. Here, we demonstrate a 10-fold enhancement in the concentration of V2 centers by combining femtosecond laser writing with an unconventional crystal plane cutting strategy, achieving high spatial accuracy on the surface of 4H-SiC. A theoretical analysis based on the differences in electronic effective mass among crystallographic planes reveals distinct ionization mechanisms under laser irradiation, which are further inferred to be a potential cause of the selective generation of defects. Based on the resulting V2 ensembles, we realize room-temperature vector magnetometry for weak magnetic fields, with an optimized detection sensitivity of 32 μT/Hz. Our results represent a significant step toward orientation-specific and site-controlled fabrication of silicon vacancies, establishing a foundational platform for their deployment in quantum sensing and quantum information processing.

Strain engineering serves as a pivotal method for modulating the electronic and optical properties of semiconductors, thereby realizing energy band engineering in low-dimensional materials. In this work, we report a strain-engineered photodetection architecture based on chirality-enriched single-walled carbon nanotubes (SWCNTs) that enables chirality-sensitive energy-band structure modulation, intramolecular junction (IMJ) formation, and gate-tunable spectral photoresponse. Height-tunable step structures are designed to introduce well-controlled uniaxial strain in SWCNT IMJ devices, allowing systematic correlation between mechanical deformation and optoelectronic behavior. Unlike conventional bulk materials or two-dimensional semiconductors, for which external strain typically induces a monotonic shift of their bandgaps, we find that devices based on SWCNT IMJs exhibit pronounced, chirality-dependent changes in photoresponse spectra under increasing uniaxial strain. The energy bandgaps extracted from spectra quantitatively follow the theoretically predicted strain-bandgap relationships with various trends for different chiral indices. Furthermore, electrostatic gating provides continuous tunability of both photocurrent amplitude and spectral response profile, showing active modulation of device photoresponse. These results demonstrate that strain-engineered IMJs in chirality-enriched SWCNT films can serve as a general method for energy band engineering and gate-tunable photoresponse, offering a practical route toward multifunctional and reconfigurable low-dimensional optoelectronic devices.

We investigate iron-cobalt (Fe-Co) alloys as a representative high-performance catalyst system for SWCNT growth in a systematic manner by combining chemical vapor deposition (CVD) experiments with chirality-resolved spectroscopic analysis, as well as molecular dynamics (MD) simulations based on density functional theory-derived machine learning force fields while varying the Fe-Co ratio. Using zeolite-based SWCNTs prepared by alcohol CVD, absorption and photoluminescence spectroscopy, together with two-dimensional excitation-emission fitting was employed to quantify chirality-specific growth efficiency. Two distinct growth regimes were identified. At a relatively low temperature of 600 C, pure Co exhibits the highest catalytic activity, promoting efficient growth of small-diameter (0.7-0.9 nm) SWCNTs. In contrast, at 850 C, the Fe0.75Co0.25 alloy shows a pronounced enhancement in growth efficiency compared with pure Fe, pure Co, and other Fe-Co compositions, also yielding larger diameter tubes (0.9-1.1nm). Similar growth behavior was observed on SiO2 substrates, enabling detailed transmission electron microscopy analysis of catalyst nanoparticles. Electron microscopy and energy-dispersive X-ray spectroscopy reveal that high SWCNT yields correlate with the formation of small, uniform Fe-Co nanoparticles with Co-enriched surfaces, in excellent agreement with MD simulations. Lastly, MD results are summarized in a composition-diameter phase diagram that rationalizes the experimentally observed growth trends. The exceptional performance of the Fe0.75Co0.25 catalyst at high temperature is attributed to the stabilization of small and uniform catalyst clusters, providing mechanistic insight into the synergistic roles of alloy composition and temperature in SWCNT growth.

Nanotubes represent an important class of crystalline materials, but controlling their structures, particularly chiralities, remains a fundamental challenge. In this work, we report a strategy for synthesizing transition metal dichalcogenide nanotubes with preferred armchair chirality. Tin disulfide, molybdenum disulfide, and tungsten disulfide nanotubes were formed with high yield and structural purity inside boron nitride nanotube channels. Atomic-resolution imaging, electron diffraction, and circular dichroism revealed an armchair preference up to 83%. Density functional theory ruled out structural stability as the origin of this preference but confirmed that zigzag nanoribbons are energetically more stable. Machine learning potential molecular dynamics simulated that zigzag nanoribbons roll up to form armchair nanotubes, a process that was subsequently observed by in situ transmission electron microscope. This work may inspire the achievement of on-demand synthesis of various nanotubes with specific chiralities.

While PbS quantum dot (QD) photodetectors exhibit promising near-infrared (NIR) response, their performance is limited by interfacial defects and damage caused by ligand-exchange processes. This study introduces a dual-interface engineering strategy: (I) A solution-processable Poly-TPD buffer layer is inserted between the PbS-halide active layer and PbS-EDT hole transport layer to mitigate EDT/acetonitrile-induced interfacial damage and improve hole extraction; (II) A controlled UV-ozone treatment is applied to the PbS-EDT layer to enhance p-doping density and reduce defect states. The optimized device achieves a dark current density as low as 74 nA cm- 2 at -0.5 V, a responsivity of 0.42 A W-1 (at 1350 nm illumination), and a specific detectivity (D*) of 2.1 × 1012 Jones, placing it among the higher-performing solution-processed PbS CQD photodiodes operating in the 1.3-1.4 µm range. This work provides a scalable approach for developing high-performance solution-processed NIR photodetectors.

Abstract Extracting radioactive iodine from waste solutions and directly converting it into functional materials with controllable structures is crucial. We report a liquid-phase strategy for confined assembly of single-atom iodine chains inside single-walled carbon nanotubes (SWCNTs). SWCNTs with diameters of 0.7–2.2 nm predominantly host single-atom chains, enabling charge transfer from tube walls to chains, forming I3– units and inducing positive charge delocalization on the tube surface, which is more pronounced in larger diameters. This charge delocalization makes large-diameter SWCNTs robust adsorbents for rapid iodine removal via electrostatic interactions across broad temperature (2–60 °C) and pH (1–5.6) ranges, achieving an exceptional removal rate (53.7 mgI2·gSWCNT–1·min–1) surpassing most reported adsorbents and enabling continuous-flow capture. The single-atom chain Ix@SWCNT also serves as a highly efficient and stable catalyst for thiol coupling, boosting the reaction rate 21-fold over homogeneous molecular I2. Spectroscopy and calculations elucidate the charge delocalization mechanism within Ix@SWCNT.

Amorphous/crystalline interfaces that combine structural distortion with local charge redistribution remain poorly understood, mainly owing to limited access to atomically well-defined single-crystalline components and correlative probes of interfacial fields. Herein, we construct atomically resolvable single-crystalline/amorphous heterointerfaces by synthesizing a library of transition metal oxytellurides and map the projected electric field and strain by combining scanning transmission electron microscopy (STEM) with four-dimensional STEM (4D-STEM). In RuTe1.93O0.97, 4D-STEM reveals a locally enhanced electrostatic field whose direction reorients at the interface. Charge density maps show electron accumulation in the amorphous region and depletion in the single-crystalline region, suggesting directional electron transfer. Nanometer-scale tensile and compressive strain localized around the heterointerface is identified. Electronic structure calculations indicate enhanced Ru 4d delocalization near the Fermi level, facilitating electron-driven reactions. This work spatially correlates atomic structure with built-in electric fields and lattice strain at disordered-ordered interfaces, providing a general route to elucidating structure-activity relationships.

The slow oxygen mass transfer and limited active-site availability at triple-phase interfaces in the air electrode hinder the high-power-density output for Zn-air batteries (ZABs). The development of synergistic optimization strategies to address these issues is critical yet challenging. Herein, we construct NiCu alloy nanoparticles (NPs) on a mesoporous-rich N-doped carbon substrate (Ni0.67Cu0.33/meso-NC) as the electrocatalyst to enlarge the micro-triple-phase interface in the catalyst layer of the air electrode. Benefiting from the mesoporous structure, Ni0.67Cu0.33/meso-NC shows good ORR activity (E1/2 = 0.883 V, jL = 5.83 mA cm-2), higher than its nonmesoporous counterpart and commercial Pt/C. Electrochemical analysis confirms the more accessible triple-phase interface active sites and accelerates the mass transfer for engineered mesoporosity in catalysts during the ORR process. In air electrodes of ZABs, a mesoporous architecture can serve as "highways" among the catalyst layers to promote oxygen diffusion and enrichment at active sites while simultaneously optimizing the specific surface area and hydrophobic/aerophilic characteristics to increase the accessible triple-phase interfaces and alleviate active-site blockage. These synergistic effects enhance the discharge performance and power density of ZABs. Consequently, the resulting Ni0.67Cu0.33/meso-NC-based liquid ZAB achieves a high peak power density of 232.6 mW cm-2 and stable operation for 400 h without obvious voltage decay. This study offers a synergistic regulation strategy of mesoporous catalysts and air electrodes for high-performance metal-air batteries.

The rapid advancements in fifth and sixth-generation (5 and 6G) mobile communication networks, along with the growing demands of the Internet of Things (IoT), necessitate the development of high-speed diodes on flexible substrates. However, most of the flexible diodes with low operating frequencies are limited by relatively low material mobility, large resistance, and capacitance. In this work, we present a flexible Schottky diode (FSBD) based on high-purity semiconducting carbon nanotube (CNT) network films, offering an innovative solution to the long-standing challenge of achieving large-area, cost-effective, high-performance radio frequency (RF) diodes on flexible substrates. Using polyimide (PI) as the substrate and a low-temperature-compatible fabrication process, the CNT-based flexible Schottky diodes (CNT-FSBDs) exhibit a remarkable responsivity of 6 A/W, an intrinsic cut-off frequency of 153 GHz, and an extrinsic cut-off frequency exceeding 10 GHz at zero bias. Furthermore, the diodes achieve efficient response at low input RF power levels (-25 dBm), owing to the low resistance, zero-bias operation, and high responsivity. These features underpin the FSBDs performance in flexible, high-efficiency rectification applications. Additionally, the CNT-FSBDs exhibit excellent uniformity and stability, making them ideal for scalable manufacturing in wearable devices, large-area sensing systems, wireless energy harvesting, and next-generation communication technologies.

The chirality-controlled growth of single-walled carbon nanotubes (SWCNTs) is important for the application of SWCNTs in high performance semiconductor devices. In this work, the chirality-selective growth of (6,5) and (9,8) SWCNTs was achieved in bulk phase, using cobalt-sulfur catalyst precursor system with MgO as the catalyst support. Under the optimal condition, characterized by UV-visible- near infrared absorption spectrum, SWCNTs of (6,5) and (9,8) accounted for 28% and 30% of the total, respectively. TEM characterizations showed bimodal diameter distribution of the as-grown SWCNTs, which is consistent with the absorption spectrum. Due to the significant difference of tube diameter, SWCNTs of (6,5) and (9,8) could be separated in aqueous two-phase system to obtain (9,8)-enriched SWCNT dispersion. Catalyst preparation condition, reduction temperature, growth temperature and carbon source affected the chirality distribution of the as-grown SWCNTs. We proposed that under the optimal condition, the diameter distribution of Co clusters presented bimodal distribution. In addition, the growth kinetics of (n,n-1)-SWCNTs is favorable against other chiralities. Therefore, the selective growth of SWCNTs of (6,5) and (9,8) may be ascribed to the dual diameter distribution of Co nanoparticles and the higher growth rates of (n,n-1)-SWCNTs. This work shows the possibility to realize the chirality-selective growth of more than one chiralities whose diameters are different significantly.

Macromolecular catalysts based on two-dimensional covalent organic polymers (COPs) with atomically dispersed transition-metal sites are promising candidates for the oxygen reduction reaction (ORR). Nonetheless, their efficiency remains constrained by the limited dioxygen activation capability inherent in planar-symmetric coordination environments. This study employs a computation-guided strategy for material design to investigate how curvature engineering of the support enhances ORR activity in COP-based catalysts. As a proof-of-concept, a onedimensional core-shell Co-COP@CNT heterostructure is fabricated through in situ Schiff-base polycondensation, resulting in a uniform Co-COP overlayer containing asymmetric CoN2O2 sites on carbon nanotubes (CNTs). Mechanistic studies reveal that the curved CNT surface induces local geometric distortion and modulates the electronic structure and chemical state of cobalt centers. This multi-dimensional control leads to optimized adsorption energetics of key intermediates by stabilizing *O2- species via curvature effects and reducing the energy barrier for *OOH formation (Delta GOOH* = 0.31 eV). Consequently, the resulting Co-COP@CNT catalyst exhibits remarkable 4e- ORR activity, featuring a high half-wave potential of 0.881 V (vs. RHE) under alkaline conditions. Moreover, it demonstrates excellent durability, operating stably for over 500 h in zinc-air batteries, along with a specific capacity of 738.1 mAh g- 1 Zn- 1 at a current density of 10 mA cm- 2.

Identifying and tuning the genuine active sites in covalent organic frameworks (COFs) is crucial for steering the oxygen reduction reaction (ORR) toward the two-electron (2e-) pathway to hydrogen peroxide (H2O2). Here, we report a systematic investigation of four isostructural COFs with pendant groups of diverse electronic nature (-H, -SO3H, -COOH, -NH2), grown as uniform shells on carbon nanotubes (CNTs). Mechanistic analyses pinpoint the beta-ketoenamine-linked carbon atom as the universal active center across all functionalized frameworks. The strongly electron-withdrawing -SO3H moiety is found to optimally polarize this site, yielding a near-ideal *OOH adsorption free energy that maximizes the 2e- selectivity. The resulting COF-SO3H@CNT heterostructure delivers an outstanding H2O2 selectivity of 97.0% in 0.1 M KOH, together with a Faradaic efficiency of 89.2% and a stable production rate of 345 mmol gcat -1 h-1 at 10 mA cm-2 in an H-cell. Operando Raman spectroscopy directly captures the potential-dependent emergence of the *OOH intermediate on the -SO3H-modified framework, while the electron-donating -NH2 group delays this signal and promotes the competing 4e- route. This work uncovers the role of substituent electronic effects in ORR branching and provides a blueprint for metal-free COF electrocatalyst design through local electronic modulation of carbon active sites.

In this paper, to exploit the synergistic effects of metal-organic framework, carbon matrix and transition metal selenide incorporation, a ZnSe/N doped carbon (ZnSe/NC) hybrid electrode was developed by controlled selenization of ZIF-8-derived carbon. A series of ZnSe/NC samples were fabricated by solid-phase reactions with different temperatures and selenium powder contents under an inert atmosphere, which effectively modulated the surface functionality and enhanced the electrical conductivity. The optimized ZnSe-1/NC-400 electrode exhibits a high specific capacitance of 462.5 F g-1 at 0.5 A g-1 in 2 M KOH electrolyte, which is 137% higher than that of unmodified NC (194.5 F g-1). In addition, it also exhibits excellent cycling stability with 83.05% capacitance retention after 5000 cycles at 10 A g-1. The morphology and microstructure of the materials were analyzed by various characterization techniques. The results showed that the specific capacitance was strongly determined by the selenide promoted formation of pyridine/pyrrole-N configurations, rather than the change in surface morphology and pore structure of the material, because of the redox-active sites to greatly improve the specific capacitance through fast Faraday reactions. The introduction of ZnSe-N-C interfaces exerts a synergistic effect to promote efficient charge transfer kinetics, and achieve the high capacitance and long cycling stability. This study demonstrates that strategic selenization of MOF-derived carbon with suitable structural and compositional alterations can provide a viable route to develop high-performance supercapacitor electrodes.

Bimetallic catalysts are crucial for chirality-selective and/or efficient growth of single-walled carbon nanotubes (SWCNTs), yet the coupled effects of alloy composition, temperature, and catalyst structure remain unclear. Here, iron–cobalt (Fe–Co) alloys are systematically investigated by combining chemical vapor deposition (CVD) experiments, chirality-resolved spectroscopy, and molecular dynamics simulations based on machine learning force fields. Using zeolite-supported SWCNTs grown by alcohol CVD, absorption and photoluminescence spectroscopy with two-dimensional excitation–emission fitting were employed to quantify chirality-specific growth efficiency. Two distinct growth regimes were identified. At 600 °C, pure Co exhibits the highest activity, favoring (6,5) and (7,5) SWCNTs. At 850 °C, the Fe0.75Co0.25 alloy shows superior growth efficiency compared with other compositions, producing larger-diameter tubes (0.9–1.1 nm). Consistent behavior on SiO2 substrates enables detailed transmission electron microscopy (TEM) analysis, revealing that high yields correlate with small, uniform nanoparticles with Co-dominated shells, in agreement with simulations. Furthermore, a composition–diameter phase diagram further rationalizes the observed trends. This phase diagram for binary clusters sheds light on the role of metal catalysts in SWCNT growth.

Next-generation wireless communication (6G), which is expected to enable far richer and unprecedented application scenarios, poses diverse challenges to conventional semiconductor technologies. These include the simultaneous requirements for high operating speed, mechanical flexibility, and radiation hardness. Fortunately, carbon nanotubes (CNTs) represent a promising emerging semiconductor that fulfills all three key attributes, owing to their intrinsic merits of high carrier mobility, exceptional mechanical flexibility, and strong covalent C-C bonding. Nevertheless, there remains a lack of experimental verification and demonstration for CNT-based flexible electronics that achieve high-speed operation and radiation hardness simultaneously. In this work, we present the first proof-of-concept demonstration of aligned carbon nanotube (ACNT)-based electronics developed for next-generation wireless communications. As a representative device architecture, we investigate ACNT-based flexible diodes exhibiting a current density exceeding 30 μA/μm, a high responsivity of 10.83 A/W, and strong nonlinearity (above 3) at near-zero bias voltage, corresponding to an intrinsic cutoff frequency of approximately 300 GHz within the terahertz regime. We further implement flexible rectifier circuits based on these ACNT diodes, which operate at frequencies approaching 30 GHz within the millimeter-wave spectrum representing the first demonstration of such performance to date. These rectifiers cover an input power dynamic range of nearly three orders of magnitude, with a minimum detectable input power as low as −30 dBm. Furthermore, our developed flexible devices can withstand a total ionizing dose (TID) of up to 3 Mrad(Si) under ambient air conditions. Collectively, the results of this work validate that high-speed ACNT-based flexible electronics serve as a highly promising candidate platform supporting multiple critical functionalities simultaneously for future wireless communication applications.

Developing micronsized silicon (Si)-based anode with high reaction kinetics and structural reversibility is highly desired. Herein, honeycomb-like Si/graphitic carbon/carbon (Si/G/C) with porous micro/nano-structure and compact covalent encapsulation is prepared based...

Single-walled carbon nanotubes (SWCNTs) are an interesting material for investigating strong light-matter coupling in the near-infrared and at room temperature due to their large exciton binding energies and stable emissions. In this work, using thin films of monochiral (6,5) SWCNTs as emitters, we study the strong light-matter coupling in three types of well-designed Fabry-Pérot microcavities with a gradual increase in the quality factor (Q factor) from ∼20 to ∼1000. We observe sharp polariton emissions in the near-infrared with a full width at half-maximum down to ∼1 meV. In the structure, exciton-like subradiant states resulting from the strong coupling manifest themselves through the relaxation dynamics of the exciton reservoir (ER). Our time-resolved photoluminescence (PL) measurements indicate that the coherence of these states can be tuned by the Q factor, which enables a high ratio of bright excitons above ∼90% relative to that of the intrinsically dark excitons in SWCNTs. With increasing Q factor, we also show that the population transfer from the ER to the lower polaritons (LPs) can be systematically enhanced. Furthermore, our angle-resolved PL spectra show a narrow distribution of the polariton emission centered around the LP ground state, which is necessary to realize the polariton condensation. These results broaden our understanding of the photophysics of both the polaritonic and subradiant states in the strongly coupled SWCNT microcavity, which will be critical for further studies on the polariton condensation and the engineering of polaritonic devices based on SWCNTs.

Highly ordered high-density arrays of single-chirality single-walled carbon nanotubes (SWCNTs) are greatly desired for exploring the intrinsic anisotropic properties and collective performance of such 1-dimensional (1D) nanomaterials. Here we present a Marangoni flow-induced self-assembly (MISA) strategy to fabricate monolayered SWCNT arrays achieving a packing density of 200 μm^-1 and a 2-dimensional order parameter (S_2D) of 0.95. Relying on its general compatibility with both organic and aqueous dispersions, we prepare single-chirality and enantiomer-pure SWCNT arrays from organic and aqueous dispersions resulting from the sorting processes. The anisotropic optical and electrical properties of the arrays are demonstrated by the polarization-dependent Rabi splitting as well as polarized near-infrared light emission and detection. With the great tolerance to solutions, substrates, and materials, as well as the feasibility and controllability, MISA shows great potential in the assembly of 1D nanomaterials.

Atomically dispersed Fe-N-C catalysts with well-defined iron-nitrogen coordination exhibit fantastic promise for the oxygen reduction reaction (ORR). However, achieving their scalable synthesis while preventing iron aggregation and performance degradation remains a critical challenge. Here, we demonstrate a highly efficient confined flash Joule heating (CFJH) technique for the scalable and ultrafast synthesis of Fe-N-C catalysts. The coal-derived porous carbons are efficient in confining iron phthalocyanine (FePc) molecules, suppressing their migration and iron aggregation during ultrafast CFJH treatment. This process facilitates the conversion of FePc into atomically dispersed FeN4 sites embedded within a graphitization-enhanced carbon framework. Mechanistic studies reveal that, compared to an FePc precursor, these integrated FeN4 sites exhibit a shifted rate-determining step with optimized adsorption/desorption of oxygen intermediates, leading to a reduced energy barrier for efficient 4e- oxygen reduction. The resulting catalyst exhibits impressive ORR activity in alkaline media with a high half-wave potential (0.90 V vs RHE) and remarkable durability (94.5% retention over 100 h). The assembled zinc-air battery delivers a peak power density of 277.6 mW cm-2 and sustains stable operation for over 900 h, outperforming the Pt/C + IrO2 benchmark. Scalable production is achieved at a rate of 0.5 kg h-1, establishing a facile and industrially viable route for synthesizing high-performance atomically dispersed catalysts.

Indium selenide (In 2 Se 3 ) has received increasing interest due to its diverse polytypes and associated polytype‐dependent ferroelectric properties, making it one of the promising platforms guiding the development of ultrathin ferroelectric nanodevices. To date, α‐, β‐, and β'‐phase In 2 Se 3 have been well studied, but nonlayered γ‐In 2 Se 3 remains underexplored because of sophisticated formation paths and minor energy differences with other phases. Therefore, understanding the growth mechanisms and electronic structures of γ‐In 2 Se 3 is crucial to present the full roadmap of the In x Se y family. Herein, a precursor‐guided chemical vapor deposition (CVD) method is proposed to selectively grow ultrathin γ‐In 2 Se 3 crystals with a nonlayered, vacancy‐ordered screw form (VOSF) structure. The sublimation temperature of precursors plays a critical role in selectively synthesizing α‐, β‐, and γ‐phase In 2 Se 3 using different precursors (In 2 Se 3 , In 2 O 3 , InCl 3 ). Ex situ scanning transmission electron microscopy (STEM) reveals a γ‐In 2 Se 3 ‐to‐InSe phase transition at 600 °C, consecutively triggered by interlayer bonds broken, vacancy reorganization and removal of Se atoms. Away from existing literature, only out‐of‐plane ferroelectricity in γ‐In 2 Se 3 , driven by vertical off‐center displacements of Se atoms, is detected. Therefore, a full spectrum of In 2 Se 3 ’s polytypes, particularly nonlayered ferroelectric γ‐In 2 Se 3 , is selectively obtained, presenting great potential for next‐generation In 2 Se 3 ‐based polytypes‐dependent nanoelectromechanical and memory devices.