Browse Articles

Thermoelectric properties of AgBiS2: Unveiling the origin of ultra-low lattice thermal conductivity and optimization strategies for electrical performance

AgBiS2, a typical I–V–VI2 compound, has attracted widespread attention in the thermoelectric community due to its inherently ultra-low-thermal conductivity. However, its practical applications are limited by inferior electrical transport properties. Herein, we systematically investigate the origin of its low lattice thermal conductivity and propose effective strategies to enhance its thermoelectric performance. Theoretical calculations reveal that the intrinsic ultra-low lattice thermal conductivity of AgBiS2 arises from multiple phonon transport features, including low-lying optical branches, rattler-like local vibration, and low phonon group velocity. Combining theoretical and experimental analyses, it is found that cation disorder suppresses cation doping effects, whereas anion doping, especially with Cl doping, is more effective in optimizing electrical performance. Furthermore, introducing additional Cu, unaffected by cation disorder, not only generates extra electrons to optimize electrical transport but also reduces thermal conductivity. Notably, Cu-doped sample achieves a significantly improved power factor of ∼3.64 μW cm−1 K−2 at 823 K, with a maximum ZT of ∼0.53, a ∼22% enhancement compared to the pristine AgBiS2. This study not only uncovers the ultra-low lattice thermal conductivity mechanisms but also validates synergistic strategies to optimize thermoelectric properties, positioning AgBiS2-based materials as promising candidates for thermoelectrics.

Effects of channel length on temperature dependence of apparent subthreshold swing in self-aligned top-gate coplanar IGZO thin-film transistors

Abstract This study investigates how channel length (L) affects the temperature dependence of the apparent subthreshold swing (SS *) in self-aligned top-gate coplanar indium-gallium-zinc oxide (IGZO) thin-film transistors (TFTs). Our experimental results demonstrate that SS * increases with temperature for devices with L = 5 μm and 7 μm, yet decreases for devices with L = 10 μm. To elucidate this behavior, we developed a drain current model based on surface potential. Our analysis reveals that variations in the dominant carrier populations (trapped versus free electrons) within the SS * extraction range dictate the observed temperature dependence of SS *. Furthermore, the lateral diffusion of donor impurities in our fabricated structures leads to notable differences in the effective channel length across TFTs with varying Ls, thereby amplifying these trends. These findings offer crucial insights into the physical mechanisms underlying the channel-length-dependent temperature behavior of SS * in IGZO TFTs. This understanding is vital for enhancing the stability of active-matrix organic light-emitting diode displays that utilize IGZO TFTs as backplanes.

A reconfigurable grating unit based on a Bragg-grating-assisted Mach–Zehnder interferometer

Bragg gratings possess unique functional attributes as fundamental integrated photonic devices. A reconfigurable grating unit based on a Bragg-grating-assisted Mach–Zehnder interferometer (GAMZI) is proposed as a versatile building block for programmable photonics. By integrating identical Bragg gratings into both arms of a thermo-optically tunable MZI, the device enables dynamic spectral reshaping—achieving bandwidth-tunable bandpass filters, phase-shifted gratings, and broadband filters with precise control over extinction ratios and bandwidths. The GAMZI architecture uniquely suppresses back-reflections while maintaining high port scalability, overcoming key limitations of conventional grating designs. Furthermore, a double-triangle recurrent network array using cascaded GAMZI units is demonstrated, enabling advanced functionalities such as ring-grating resonators, sampled gratings, and on-chip coarse wavelength division multiplexing. This work establishes a scalable and reconfigurable platform for on-chip spectral engineering, paving the way for adaptive optical signal processing in next-generation programmable photonic circuits.

Detection of unseen malware threats using generative adversarial networks and deep learning models

Fe contribution to the magnetic anisotropy of L10-ordered FePt thin films studied by angle-dependent x-ray magnetic circular dichroism

Among magnetic thin films with perpendicular magnetic anisotropy (PMA), L10-ordered FePt has attracted significant attention because of its exceptionally strong PMA. However, the microscopic origin of its strong PMA has not been elucidated experimentally. We have investigated the contribution of the Fe 3d electrons to its magnetic anisotropy energy by angle-dependent x-ray magnetic circular dichroism at the Fe L2,3 edge. By this technique, one can deduce the magnetic dipole moment mT, which represents the anisotropic spatial distribution of spin-polarized electrons, and the orbital moment anisotropy (OMA) of Fe 3d electrons. Detected finite mT indicates that the spin-polarized Fe 3d electrons are distributed preferentially in the out-of-plane direction of the films. This mT of Fe overwhelms the positive contribution of OMA to PMA and reduces the PMA of L10-ordered FePt thin films, consistent with a previous first-principles calculation. The present result implies that a large positive contribution of the non-magnetic element Pt rather than Fe governs the PMA of L10-ordered FePt thin films.

Non‐Fused Conjugated Alkylfluorene Bridged Naphthalimides Cathode Interlayer Enables Low‐Noise Near‐Infrared Organic Photodiodes

AbstractThe cathode interface layers (CILs) play a crucial role in enhancing the performance of organic photodiodes (OPDs). However, the poor film formation, the tendency of orientation and aggregation, and contact in the interface of the bulk heterojunction (BHJ)/CILs/electrode increase the dark current, leading to a limitation of light detection. In this study, we designed and synthesized a nonfused conjugated small molecule (FNA) with dioctyl fluorene (F) as the π‐bridge and N‐dimethylaminopropyl‐1,8‐naphthalimide (NA) as terminal groups. As the CIL, it significantly modifies the interfaces of BHJ/CILs/electrode and minimizes dark current density (Jd). Using PTB7‐Th:IEICO‐4F as the BHJ, FNA‐based OPDs achieve a remarkably low Jd of 1.12 × 10−8 A cm−2 (at −0.5 V) and a peak specific detectivity of 8.23 × 1012 Jones (940 nm), outperforming conventional devices with PDINN as CIL. These improvements are attributed to lower Jd by modified interfacial contact and increased photoresponse by reducing depletion region width in FNA‐based photodiodes. Furthermore, uniform photoresponse in 5 × 5 OPD pixel arrays further validates its potential for imaging applications.

Alterations in mineral and biochemical traits of Artemisia haussknechtii Boiss. populations by soil and environmental factors

Multifunctional hole transport layer enhances high-performance pure-red perovskite quantum-dot light-emitting diodes

The performance of perovskite light-emitting diodes (PeLEDs) has advanced rapidly; however, the development of suitable hole transport layers (HTLs) for PeLEDs remains a critical challenge. This study introduces a multifunctional HTL of poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-(4,4′-(N-(4-[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]phenyl)diphenylamine))] (TFTEG), which features a backbone similar to that of the commercial hole transport material poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-(4,4′-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), while its side chain is modified to include multiple ether groups. Theoretical calculations and experimental characterizations demonstrate that TFTEG not only significantly enhances hole injection but also effectively passivates uncoordinated Pb2+ defects at the buried interface through Lewis acid–base interactions. This substantially improves the photoluminescence and electroluminescence (EL) quantum yields of perovskite quantum dots (QDs). Pure-red quantum-dot PeLEDs that employ TFTEG as the HTL achieve a maximum external quantum efficiency of 9.67%, which signifies a substantial enhancement over the 4.56% efficiency observed in control devices utilizing the commercial TFB HTL. Furthermore, TFTEG contributes to a reduced turn-on voltage, enhanced brightness (1741 vs 888 cd m−2), and a stable EL spectrum peaking at 650 nm. The rapid response characteristics underscore its promising potential for high-speed optoelectronic applications, such as wireless communication systems.

HerTACs Enable Tumor‐Selective Lysosomal Degradation of Membrane and Extracellular Proteins via HER2 Trafficking

AbstractTargeting extracellular and membrane proteins for degradation remains a frontier challenge in the field of targeted protein degradation (TPD), largely due to the intracellular confinement of existing proteolysis systems and reliance on bulky biologics. Here, we develop a novel TPD platform, human epidermal growth factor receptor 2 (HER2)‐targeted lysosome‐tethering chimeras (HerTACs), which co‐opts the tumor overexpressed, endocytic, and lysosomal trafficking capability of HER2. Starting from the HER2‐binding peptide LTVSPWY, we engineered the first‐generation HerTAC (LP), a conjugate of the HER2‐binding peptide and a PD‐L1 ligand, to degrade programmed death ligand 1 (PD‐L1) in HER2‐positive cells. Guided by AlphaFold modeling and alanine scanning, we developed a stapled peptide‐based HerTAC (L2,5P) with enhanced degradative efficacy (DC50 = 156 nM), stability, and pharmacokinetics. HerTAC L2,5P showed potent antitumor activity and low systemic toxicity in HER2+ breast cancer animal models. The HerTAC strategy was further extended to other clinically relevant inaccessible membrane and extracellular targets (i.e., V‐domain Ig suppressor of T cell activation [VISTA] and macrophage migration inhibitory factor [MIF]), highlighting its generality and broad applicability. This work establishes a tumor‐selective, lysosome‐directed TPD strategy that expands the druggable proteome and offers a clinically transformable approach for precision oncology.

New insights to effective carbon nanofiber features due to defective interphase for prediction of tunneling conductivity in composites

Harnessing Rashba–Edelstein effect at Pt/DyOx interface for efficient spin–orbit torques

Spin–orbit torque (SOT) can be enhanced through the interfacial Rashba–Edelstein effect, which arises in systems with broken inversion symmetry and converts charge current into nonequilibrium spin accumulation, thus boosting spin current. Despite its known effects, the role of 4f-electron lanthanide oxides in influencing interfacial phenomena has remained largely unexplored. In this study, we investigate the potential of f-electron lanthanide oxides, particularly at the Pt/DyOx interface, to enhance SOT. The gradient oxidation structure of the 4f-electron rare-earth oxide DyOx was confirmed through ultra-high-precision line scanning electron energy loss spectroscopy. By employing spin–torque ferromagnetic resonance, we achieve an extraordinary SOT efficiency of ξFMR = 0.758 in the Pt/DyOx heterojunction, exceeding that of pure Pt by more than a factor of ten. This enhancement reduces the critical current density required for magnetization switching to 2.25–3.48 × 106 A·cm−2, which is only 15% of the current density needed for pure Pt. Beyond improving SOT efficiency, the integration of 4f rare-earth oxides at the interface provides an advanced technical pathway for developing CMOS-compatible and energy-efficient spintronic technologies.

A new molecular seed assay to predict Ustilago nuda field infection levels

Deactivating charged states in colloidal quantum dots by Förster resonance energy transfer

Colloidal quantum dots (QDs) possess size/shape/surface-tunable optical and electronic properties, making them promising building blocks for optoelectronic applications. However, the fluorescence intermittency, also known as “blinking,” observed in individual QDs is a pervasive phenomenon. The dark state (trion state) in blinking experiences non-radiative recombination processes, such as trap-mediated recombination and Auger–Meitner recombination, which significantly diminish the quantum efficiency of the QDs. Despite efforts to mitigate blinking phenomena through chemical engineering of QDs structures and their environments, blinking continues to impede the application of single QDs, particularly in single photon sources. This study demonstrates that Förster resonance energy transfer (FRET) from green QDs (donor) to individual red QDs (acceptor) can effectively suppress fluorescence intermittency. The findings indicate that FRET facilitates the removal of excess charges from the charged state (dark state, trion state), allowing the QDs to transition from the lower quantum yield trion state to the higher quantum yield single-exciton state (bright state). Our research confirms that FRET can inhibit fluorescence intermittency by deactivating the charged state.

Deciphering the Role of Fluorination in Dual‐Halogen Electrolytes for All‐Solid‐State Batteries: A Case Study of New Li₂HfCl_6−xF_x Solid Electrolytes

AbstractLithium metal chlorides are promising superionic conductors for all‐solid‐state batteries (SSBs) due to their favorable mechanical properties, high ionic conductivity, and good oxidative stability (up to >4.2 V versus Li/Li+). Nonetheless, chloride solid electrolytes (SEs) still undergo electrochemical degradation when paired with high‐voltage cathodes such as LiNi0.85Co0.1Mn0.05O2. A viable strategy to enhance the intrinsic electrochemical stability of chloride electrolytes is to partially substitute Cl with F. By leveraging complementary insights from neutron and X‐ray diffraction, X‐ray absorption spectroscopy, X‐ray photoelectron spectroscopy (XPS), time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS), and electrochemical studies, we investigate the interplay between ionic and electronic conductivity, voltage stability, and overall battery performance of a family of new dual‐halogen SEs—Li2HfCl6−xFx. All‐solid‐state cells utilizing Li2HfCl5.5F0.5 as the electrolyte demonstrate much‐enhanced battery performance compared to Li2HfCl6. This improvement is mainly attributed to the formation of a kinetically stable LiF‐rich cathode electrolyte interphase (CEI), which inhibits detrimental reactions between the cathode and the SE, as revealed by ToF‐SIMS studies. The findings from this study are applicable to other dual‐halogen solid ionic conductors, offering valuable insights into the relationship between intrinsic electrochemical window (IEW), electronic and ionic conductivity, and battery performance in dual‐halogen solid‐state electrolytes.

Bioinformatic analysis of brucellosis and construction of a diagnostic model based on key genes

Ytterbium dopant-manipulated neuromorphic behavior for wavelength-dependent dual-modal photodetection

Integrating sensing and neuromorphic functions within a single low-power platform remains a key challenge in optoelectronic device design. We report a dual-modal perovskite photodetector by incorporating YbCl3 as a dopant, which simultaneously achieves neuromorphic behavior and conventional optoelectronic properties. Systematic characterizations of doping manipulation reveal that 0.5% YbCl3 can optimally modulate film crystallinity, enhance carrier transport, and tune charge dynamics. Notably, the 0.5% doped device exhibited distinct wavelength-dependent photoresponse, and hallmarks of depression-like neuromorphic behavior are were observed under pulsed 905 nm light excitation. This behavior is clearly supported by negative photoconductivity, gradual baseline modulation, and a prolonged post-illumination tail. However, these adaptive current dynamics are absent under 635 nm light illumination; the device instead demonstrated enhanced photoresponse, with responsivity increasing from 0.45 to 0.73 A/W and detectivity from 1.4 × 1012 to 5.1 × 1012 Jones. This spectral contrast originates from the wavelength-dependent activation of Yb3+-related trap states, confirmed by photoluminance measurements. These findings position YbCl3 doping as a versatile strategy for advancing perovskite photodetectors toward dual-modal photodetection, with ongoing studies exploring broader applicability.

Anti-inflammatory myeloid angiogenic cells (MIL4-MACs) attenuate angiotensin II‒induced heart failure in mice

Topology‐Engineered Guide RNAs for Programmable Control of CRISPR/Cas Activity

AbstractCRISPR/Cas systems have transformed genome editing, yet achieving precise temporal and conditional control remains challenging. Traditional strategies involving linear guide RNAs (gRNAs) modified with multiple chemical groups throughout their strands often face limitations such as heterogeneous reaction outcomes, irreversibility, and variable editing efficiencies. To overcome these issues, topology‐engineered guide RNAs (TE‐gRNAs) have emerged, featuring defined structural architectures including polymeric, circular, and dendrimer‐like topologies that enable precise spatial control, reversibility, and programmable activation of CRISPR activity. By selectively incorporating physical or chemically responsive linkers and stimuli‐sensitive groups at specific sites, TE‐gRNAs facilitate dynamic and conditional genome editing that can be activated or deactivated with external triggers such as light or chemical signals. These engineered RNA structures significantly improve synthesis feasibility, stability, reduce off‐target effects, and provide unprecedented control over gene editing processes. Recent advancements in TE‐gRNAs demonstrate their broad applicability in synthetic biology, functional genomics, and therapeutic interventions, highlighting their potential to achieve precise spatiotemporal modulation of CRISPR systems. This review summarizes the current strategies, benefits, and challenges associated with TE‐gRNAs, and discusses future directions for enhancing their performance and utility in complex genome editing applications.

<i>tert</i>‐Butyl Functionalized Ultra‐Microporous Three‐Dimensional Covalent Organic Framework for Efficient SF₆/N₂ Separation

AbstractEfficient capture and recovery of sulfur hexafluoride (SF6) from SF6/N2 mixtures is critical for mitigating greenhouse effects and promoting gas recycling in the electronics industry. Herein, we report a novel ultra‐microporous three‐dimensional covalent organic framework (COF), termed CPOF‐12, enriched with tert‐butyl groups. CPOF‐12 exhibits a Brunauer−Emmett−Teller (BET) surface area of 1,140 m2 g−1, a pore volume of 0.66 cm3 g−1, and a uniform pore size of 0.59 nm, which closely matches the kinetic diameter of SF6 (0.52 nm). Gas adsorption measurements reveal a high SF6 uptake of 2.20 mmol g−1 at 298 K and 1 bar, along with an exceptional SF6/N2 selectivity of 149.4, calculated using ideal adsorbed solution theory (IAST). This study highlights the effectiveness of pore surface engineering in COFs for high‐performance separation of greenhouse gases.

Relative performance of three phylogenetic methods based on complete mitochondrial genomes of barnacle