Small Methods最新文献

Proton (H⁺) doping effectively modulates the metal-insulator phase transitions of vanadium dioxide (VO₂) via its reversible incorporation into interstitial sites, providing exotic physical functionalities and emerging applications. Although selective area proton doping is crucial for neuromorphic electronics, the spatial proton propagation and the related phase transitions remain unclear. Herein, we demonstrate the control of proton propagation and the phase transitions of hydrogenated VO₂ films by engineering the size and spacing of platinum (Pt) catalysts. Raman spectroscopy reveals that protons propagate for ∼4 µm, with an accompanying phase transition, in VO₂ films modified with micro-sized Pt catalysts. Together with Kelvin probe force microscopy (KPFM) data, these results demonstrate that hydrogen diffusion induces three distinct phases in the H_xVO₂ film around the Pt catalyst. The electronic phase transitions can be well manipulated by controlling proton propagation. The Pt nanoparticle catalysts with nanometer spacing significantly enhance hydrogen propagation and accelerate the rich phase transitions of H_xVO₂ films at a low hydrogenation temperature (100°C). The proton-doping-induced phase transformation is further confirmed by theoretical calculations of the geometric and electronic structures. The insights into spatial proton propagation provide critical guidance for controlling the electronic phase transitions and optimizing the energy-efficient VO₂-based ionic and electronic applications.

Three-photon fluorescence microscopy (3PFM) enables high-resolution volumetric imaging in deep tissues but is fundamentally constrained by a trade-off among imaging speed and spatial resolution, due to low photon flux and prolonged laser exposure. We present DeepR-SXYZ, a deep learning framework that achieves pixel dwell time equivalent to hundreds of nanoseconds (0.168-0.38 µs) through sparse X-Y-Z reconstruction for 3PFM. Trained on paired datasets consisting of sparsely acquired low-resolution volumetric scans (e.g., 256 × 256 pixels, 1.2 µs per pixel, Z step: 16 µm) and their corresponding densely sampled high-resolution counterparts (e.g., 512 × 512 pixels, 3.2 µs per pixel, Z step: 2 µm), DeepR-SXYZ integrates convolutional neural networks (CNNs) with a structure-dynamic attention (SDA)-enhanced transformer, synergistically capturing intra-layer morphological features (for X-Y plane reconstruction) and inter-layer dynamic variations (for Z-axis interpolation). This design enables accurate 3D volume reconstruction from sparsely sampled data. Experimental validation on cerebral vasculature and muscle macrophages demonstrates that DeepR-SXYZ achieves 8.8× acceleration in X-Y plane imaging over conventional dense sampling and >60% Z-axis layer recovery, substantially improving imaging throughput and reducing single-pixel dwell time significantly. Crucially, the framework enables large-field 3D cerebral vasculature imaging and dynamic volumetric tracking of cellular behaviors, revealing previously inaccessible spatiotemporal biological processes. This work establishes a computational paradigm for high-speed, low-phototoxicity three-photon fluorescence microscopic imaging via sparse X-Y-Z reconstruction, effectively balancing imaging speed and spatial resolution.

1D chiral perovskites, exhibiting anisotropic and chiroptical activities, are highly promising candidates for full-Stokes polarization detection. However, inefficient chirality transfer in these materials results in weak chiroptical responses, seriously limiting their capability for circular polarization discrimination. Here, we develop a facile Sb³⁺ doping strategy to effectively modulate the structural asymmetry of (R/S-3AD)PbBr₃Cl·H₂O crystals (3AD = 3-aminopiperidine dihydrochloride), significantly enhancing the chirality transfer from chiral organic components to inorganic framework owing to the symmetry-breaking lattice distortions and yielding a 30-fold increase in chiroptical activity. Furthermore, the doped chiral perovskite crystals exhibit a pronounced Dember effect, enabling self-driven photodetection. As a result, the Sb³⁺-doped (R/S-3AD)PbBr₃Cl·H₂O crystals achieve a maximum circular polarization sensitivity factor of 0.44 and a linear polarization ratio of 1.43 at zero bias, allowing accurate full-Stokes polarization detection with a Stokes parameter averaging error below 7%. This study offers a new strategy for boosting the chiroptical responses in chiral perovskites and presents the first demonstration of self-driven full-Stokes photodetection via the Dember effect.

Organic small molecules are promising high-capacity anodes for potassium-ion batteries (PIBs), but their practical application is severely hampered by active material dissolution, persistent parasitic reactions at the solid-electrolyte interface, and sluggish reaction kinetics, resulting in rapid capacity decay. To holistically address these multifaceted drawbacks, this work demonstrates a synergistic multi-scale confinement engineering strategy through coordinated design at the molecule-ion-electron levels. Specifically, active molecules are physically confined within the ordered mesopores of conductive CMK3 carbon, ensuring structural stability and efficient electron transport. Concurrently, a high concentration electrolyte (3 m KFSI in EC/DEC) is employed to tailor the solvation environment, regulating anion activity, and stabilize the interface. At the molecular scale, an electron-withdrawing fluorine substituent is used to optimize electronic structure, enhancing potassium storage kinetics and capacity. The resulting 2FBA@CMK3 anode delivers an impressive reversible capacity of 152 mAh/g after 400 cycles at 500 mA/g, outperforming most reported organic PIB anodes. This work establishes a holistic and rational design paradigm for advancing organic electrode materials toward high-performance PIBs.

Serious non-radiative recombination at the interface hinders the improvement of power conversion efficiency (PCE) and stability in perovskite solar cells (PSCs). Meanwhile, the development of a comprehensive strategy for nontoxic and low-cost additives to reduce surface defects in the perovskite absorber is a critical issue for the industrialization of PSCs. Herein, an organic compound extracted from Sugar orange peel (SPE), which simultaneously contains C═C bonds and methoxy groups, can act as a Lewis base to incorporate into perovskite for the passivation of undercoordinated Pb²⁺. To address the stability issue originating from iodide ion vacancies and organic cation vacancies, a synergistic passivation strategy by utilizing SPE and low-toxicity piperazine dihydroiodide (PDI) was applied for the passivation at the perovskite/C₆₀ interface. This strategy facilitates the in-situ reconstruction of the perovskite film, yielding a homogeneous microstructure that minimizes the contact resistance at the perovskite/C₆₀ interface. Furthermore, the synergistic effect of SPE and PDI markedly suppressed energy level mismatch-induced and defect-induced nonradiative recombination losses at the perovskite/C₆₀ interface. Ultimately, the SPE&PDI-treated PSC achieved a champion PCE of 25.4% and retained over 84% of its efficiency after being continuously annealed at 85°C for 1200 h.

Three-dimensional self-assembled cellular aggregates, such as spheroids, provide unique building blocks for bottom-up tissue engineering and in vitro disease modeling. Nevertheless, traditional spheroid production methods require prolonged cell aggregation times and are highly dependent on cell type, requiring frequent optimization steps. Additionally, spheroids' size is dependent on their cell density, preventing a control over their final volume. Herein, a methodology combining metabolic glycoengineering and click chemistry with superhydrophobic surfaces is described to rapidly create spherically structured living bead units, that can surpass the fabrication constraints of conventional spheroids. Compared to spheroids produced in low attachment settings, the living beads comprising various cell types (i.e., stem, endothelial, and cancer cells) are rapidly produced and demonstrate enhanced cell viability and cell spreading over 14 days, while maintaining principal spheroid characteristics, namely the fusion into multi-scale living materials and cellular migration capabilities. In addition, this methodology enables the production of living beads with controlled size, independently of cell density, overcoming a key limitation of current spheroid production methods. The enhanced reproducibility, reduced cell assembly time, and improved handling make these spherically structured living beads a valuable alternative, with broad application in bottom-up tissue engineering approaches and disease modeling applications.

The integration of functional metal-oxide nanomaterials into high-performance devices is contingent on their precise patterning into two- or 3D nanostructures. Nevertheless, the limited solubility and poor film-forming properties of these materials pose significant challenges for nanopatterning. Conventional methodologies are predicated on the utilization of photoresist for the lithographic pattern transfer to metal-containing layers, a process that complicates the overall process. In this work, we present a photoresist-free lithographic approach that uses solution-processable, carboxylic acid-modified titanium oxide nanoparticles (TiO₂ NPs), which are rationally synthesized via controlled coordination-hydrolysis reactions, to realize TiO₂ nanopatterning. Electron beam exposure has been demonstrated to enable sub-20 nm patterning, achieving feature sizes as small as 14 nm without the need for an additional sacrificial photoresist layer. The patterning mechanism, involving electron-induced dissociation of carboxylic acid ligands, has been confirmed by X-ray photoelectron spectroscopy and thermogravimetric-mass spectrometry. The post-annealing treatment has been demonstrated to preserve the structural integrity of the nanopatterns, whilst concomitantly promoting the crystallization process, resulting in the formation of anatase or anatase-rutile mixtures. This method facilitates the fabrication process whilst enabling high-resolution TiO₂ patterning, thus offering a promising route for advanced device integration.

Tailoring passivators to modulate surface defects of perovskite films represents a pivotal approach to simultaneously improving the optoelectronic properties and long-term operational stability of perovskite solar cells (PSCs). The design of passivators that simultaneously achieve surface passivation and charge extraction is particularly crucial. Herein, we report a dual-site synergistic passivation material, 1-naphthalenethylamine iodide (NEAI1), which is low-cost, structurally simple, and has π-π regulatory effects. It is incorporated into the interfacial passivation layer between the perovskite films and the hole transport layer (HTL). Theoretical calculations show that NEAI1 with naphthalene conjugated structure exhibits stronger electron delocalization ability and larger molecular dipole moment, which can effectively induce interfacial charge transfer. Therefore, NEAI1 showed a champion power conversion efficiency (PCE) of 25.33% and still retained 93.47% of the initial value after storage for about 2200 h, demonstrating excellent device stability. In addition, NEAI1 effectively reduces losses caused by perovskite defects by coordinating with uncoordinated Pb²⁺ and compensating for iodine vacancies through a dual-site synergistic passivation mechanism.

Lithium-sulfur batteries (LSBs) are one of the most promising candidates for next-generation energy storage due to their high theoretical energy density and cost-effective active material. However, challenges such as polysulfide shuttling and lithium metal instability hinder their practical deployment. To tackle these challenges, in this study, we delve into the critical impacts of salt anion in the electrochemical performance of LSBs, focusing on a family of localized high-concentration electrolytes (LHCEs) comprising two prevalent anions [i.e., lithium bis(fluorosulfonyl)imide (LiFSI) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)]. While higher LiFSI content enhances ionic conductivity, SEI formation, and lithium metal compatibility, it also reduces sulfur utilization due to side reactions with long-chain polysulfides. Post-mortem analyses confirm the formation of insulating species in high-LiFSI formulations. An optimal electrolyte composition with 0.2 m LiFSI as co-salt offers excellent electrochemical performance, achieving enhanced lithium protection and stabilized sulfur redox reactions. These findings reveal the coordination-dependent, double-edged nature of LiFSI and provide key insights for electrolyte design in high-performance LSBs.

Electrolytes critically influence the electrochemical performance and cycle life of lithium ion batteries (LIBs). This holds especially for organic redox polymer-based batteries, such as those employing poly(3-vinyl-N-methylphenoxazine) (PVMPO), where solubility limits performance in conventional ethylene carbonate (EC)/ dimethyl carbonate (DMC)-based electrolytes. Reducing EC content has shown solubility suppression when using ethyl methyl carbonate (EMC) as a co-solvent, however, capacity fading persists due to PVMPO electrode degradation. To address this degradation, this study explores the use of EC-free electrolytes, with and without fluoroethylene carbonate (FEC). Electrochemical investigations, UltraViolet/Visible (UV/Vis) spectroscopy, post-cycling Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) mapping, and X-ray Photoelectron Spectroscopy (XPS) analyses are employed to evaluate solubility, interfacial properties, and electrode integrity. The EC-free electrolyte system with FEC retains 95 mAh g^‒1, while that without FEC retains 86 mAh g^‒1, outperforming the 76 mAh g^‒1 observed in EC-based systems after 500 cycles at 1C. FEC containing electrolyte systems display reduced interfacial resistance, fewer surface cracks, and minimal electrode degradation. These findings demonstrate that EC-free electrolytes, particularly with FEC, effectively suppress electrode degradation and enhance the cycle life of organic LIBs.