Multi-walled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) were embedded into poly(vinylidene fluoride) (PVDF) electrospun fibers with varying mass fractions (0–4 wt%). In addition, the hybrid combinations at 1.5 wt.% GNP/MWCNT/PVDF were fabricated to evaluate potential synergistic effects. The electrospun fiber mats were thermally post-treated at 145°C for 3 and 6 h to assess the influence of annealing on the microstructure, crystalline phase composition, and functional performance. The morphological, structural, mechanical, and piezoelectric properties were examined in relation to both the distinct geometries of the fillers and the thermal annealing. The combination of annealing and nanofiller-induced nucleation significantly improved the crystallinity of the fibers. The tensile strength increased up to 11.1 MPa for 0.5 wt.% MWCNT/PVDF and 15.7 MPa for 1.5 wt.% GNP/PVDF after 6 h of annealing. Structural analysis revealed a pronounced α→β phase transition in the 1.5 wt. % hybrid compositions, reaching a β/α ratio up to 7.8 substantially greater than the transitions observed for mono-filler systems: 4.7 for 1.5 wt.% GNP/PVDF and 3.0 for 1.5 wt.% MWCNT/PVDF. The effect of the high β-phase content was further confirmed at the nanoscale by piezoresponse force microscopy (PFM), which showed a consistent piezoelectric response through the fibers: a coercive voltage of approximately ± 40 V, which decreased to ± 20 V, ascribed to the dispersed nanofillers within the fiber. These results demonstrate that combining hybrid carbon fillers with controlled annealing enables tunable crystalline structures and enhanced electromechanical performance in electrospun PVDF nanofibers. • hybrid GNP/MWCNT fillers drive synergetically β-phase nucleation mechanisms. • The interfacial interaction between PVDF and carbon fillers was quantified using Piezoresponse Force Microscopy (PFM) measurements. • PFM confirmed a consistent piezoelectric response with coercive voltage decreasing from ± 40 V to ± 20 V due to dispersed nanofillers • Hybrid fillers and annealing tailor PVDF crystallinity and functional performance.

This paper reports an innovative process to fabricate β -Ga 2 O 3 microtubes and nanomembranes based on ion implantation in (100)-oriented single-crystals. We show that the detachment and rolling-up of a thin surface layer, forming a microtube, can be promoted by the implantation-induced strain profile. The strain-disorder interplay was investigated in detail for Cr-implanted β -Ga 2 O 3 with complementary methods, showing an excellent agreement between experiments and simulations, and suggesting an exfoliation mechanism that is correlated with the anisotropic nature of the β -Ga 2 O 3 monoclinic system and its easy-cleavage planes. Moreover, these microtubes are transferrable to other substrates and can be unrolled under thermal annealing, resulting in nanomembranes with bulk-like crystalline quality. A study of the evolution of the implantation-induced damage under annealing showed a remarkable recovery at moderate temperatures (∼500°C). This method thus shows potential for the scalable production of nanomembranes and can be realized employing any ion species, providing simultaneous doping.

Despite spray-flame synthesis (SFS) enabling versatile production of functional iron oxide nanomaterials, systematic studies quantifying structure-purity-function relationships remain scarce. Moreover, γ-Fe 2 O 3 /Fe 3 O 4 differentiation is accompanied by methodological uncertainties, while methods to systematically compare material purities are lacking. Here, we present a systematic comparison of iron oxides synthesized from iron(III) nitrate nonahydrate (INN) in pure ethanol (EtOH) vs. ethanol/2-ethylhexanoic acid (EtOH + EHA) using the standardized SpraySyn1 burner, employing Mössbauer spectroscopy for unambiguous phase identification. We further introduce particle surface loading ( PSL ) as a size-independent metric for surface impurities, enabling systematic purity comparison across synthesis conditions. Evaluating structure, purity, and functionality measured by vibrational scanning magnetometry (VSM) and oxygen evolution reaction (OER) demonstrates that INN in EtOH + EHA predominantly yields small γ-Fe 2 O 3 particles (<10 nm, ~95 wt%) with ~60% higher organic PSL than pure EtOH, yet exhibiting superparamagnetism despite moderate polydispersities. In contrast, INN in EtOH produces bimodal distributions containing ~20 wt% α-Fe 2 O 3 , benefiting OER activity. Thermal annealing at 250 °C eliminates surface-bound carbonaceous species and induces diffusion-driven sintering. Consequently, PSL decreases while Fe 2 O 3 content increases and particles exhibit increased crystallinity and size. Thus, thermally annealed samples from INN in EtOH + EHA exhibit doubled magnetic response (~50 emu/g vs. ~20 emu/g as-synthesized) while maintaining superparamagnetism. However, annealing decreases catalytically active sites, diminishing OER activity across all samples. These structure-purity-function correlations establish application-specific design guidelines: INN in EtOH + EHA with thermal annealing yields γ-Fe 2 O 3 suitable for magnetic applications, while as-synthesized samples from pure EtOH exhibit higher OER activity. • Solvent choice alters structure, purity, and functionality of nanoscale iron oxide • PSL metric enables size-independent quantification of surface-bound by-products • Definitive phase identification via Mössbauer spectroscopy • Moderate size-polydispersity preserves superparamagnetism in γ-Fe 2 O 3 samples • Thermal annealing enhances M S but reduces OER via diffusion-driven sintering

The direct recycling of spent cathode materials is a promising strategy for a sustainable supply chain but remains challenging for industrial-sourced cathode black mass due to its complex morphology and heterogeneous impurities. Here, we report an all‑dry and scalable process that directly regenerates spent LiNi0.5Co0.2Mn0.3O2 (NCM523) black mass into high‑performance cathode materials. By integrating plasma-assisted mechanochemistry with thermal annealing, the process simultaneously refines particle morphology, enhances the relithiation kinetics, and converts trace impurities (Al, Na) into beneficial dopants through plasma-enabled defluorination and homogeneous incorporation. This enables complete recovery of the layered structure with controlled single-crystal morphology and preferential (003) facet exposure. The regenerated NCM523 delivers a high specific capacity and long-term cycling stability, retaining 82.6% of its initial capacity after 300 cycles at a high cut-off voltage of 4.5V. Practical scalability of this approach is demonstrated through the batch processing of kilogram-level black mass, and a 2Ah pouch cell maintains 97.1% capacity retention over 1000 cycles. This work provides a practical solution for transforming battery black mass into high‑value cathode materials.

We investigate the self-assembly of two-dimensional dodecagonal quasicrystals driven by cyclic shear, effectively replacing thermal fluctuations with plastic rearrangements. Using particles interacting via a smoothed square-shoulder potential, we demonstrate that cyclic shearing drives initially random configurations into ordered quasicrystalline states. The resulting non-equilibrium phase diagram qualitatively mirrors that of thermal equilibrium, exhibiting square, quasicrystalline, and hexagonal phases, as well as phase coexistence. Remarkably, the shear-stabilised quasicrystal appears even where the zero-temperature equilibrium ground state favours square-hexagonal coexistence, suggesting that mechanical driving can stabilise quasicrystalline order in a way analogous to entropic effects in thermal systems. The structural quality of the self-assembled state is maximised near the yielding transition, even though the dynamics are slowest there. Yet, the system still quickly forms monodomain quasicrystals without any complex annealing protocols, unlike at equilibrium, where thermal annealing would be required. Finite-size scaling analysis reveals that global orientational order decays slowly with system size, indicative of quasi-long-range order comparable to equilibrium hexatic phases. Overall, our results establish cyclic shear as an efficient pathway for the self-assembly of complex structures.

Thermal annealing is a widely used thin-film processing technique for modifying interfacial optical losses and electronic scattering in metals. Here, we investigate how thermal annealing of gold thin films deposited on silicon carbide substrates influences interfacial near-field radiative heat transfer (NFRHT) across nanoscale vacuum gaps. Using experimentally measured dielectric functions for annealed and unannealed Au films, we evaluate the spectral and total radiative heat flux between Au/SiC interfaces within a fluctuational electrodynamics framework. We show that annealing-induced changes in the low-frequency dielectric losses of Au significantly alter evanescent electromagnetic coupling at the interface, leading to enhancements of up to 40% in the total NFRHT at separations of tens of nanometers. Mode-resolved analysis reveals that this enhancement originates from strengthened coupling of overdamped evanescent-surface modes, which are highly sensitive to thin-film processing and interfacial microstructure. These results demonstrate that standard thin-film processing can substantially modify near-field coupling through purely dielectric-property variations. The magnitude of this effect is comparable to variations often attributed to geometric uncertainty or gap calibration in experiments, highlighting the importance of material processing in the interpretation and control of NFRHT measurements.

Strained Si/SiGe heterostructures are key enablers of high‐mobility and long spin‐coherence electron systems, making them essential for cryogenic electronic and spin qubit devices. The strain‐induced conduction band offset in these structures supports the vertical confinement of electrons, enabling the formation of a two‐dimensional electron gas (2DEG), a basic building block for gate‐defined quantum dot devices. However, high‐temperature processes during (Bi)CMOS fabrication, particularly contact formation, can relax the desired strain and thereby degrade electronic performance. In this work, we investigate the combined influence of sequential phosphorus ion implantation and rapid thermal annealing (RTA) on Si 0.67 Ge 0.33 /Si/Si 0.67 Ge 0.33 heterostructures processed in an industry‐standard 200 mm BiCMOS pilot line. By dividing a high‐dose phosphorus implant into multiple lower‐dose steps and optimizing the annealing conditions, we effectively suppress Si–Ge interdiffusion, thereby preserving strain and heterostructure integrity. To enhance homogeneity across the wafer, nickel silicide (NiSi) metallization is applied for contact formation. The resulting Hall bar‐shaped field‐effect transistors (HB‐FETs) exhibit reliable Ohmic behavior and a specific contact resistivity of 7.68 × 10 − 7 Ωcm 2 at 1.5 K. These results demonstrate a scalable, process‐compatible route to forming low‐resistance contacts in strained Si/SiGe heterostructures while maintaining the structural and electronic properties required for quantum device fabrication.

We present a nonprecious NiMo-based cathode with high activity and durability for proton exchange membrane water electrolysis, achieved via selective Zn dealloying and subsequent thermal annealing. This synergistic strategy simultaneously increases the electrochemically active surface area, achieving 1.897 A cm-2 at 2.0 Vcell, and ensures structural stability in acidic media.

The integration of metal-organic framework (MOF) thin films into functional devices is currently hindered by high temperatures, prolonged processing times, and complex additives required by conventional fabrication methods. We demonstrated a plasma-assisted strategy to directly synthesize crystalline MOF films on metal substrates under ambient conditions and overcome these kinetic and processing limitations. We used a HKUST-1 on a copper substrate as a model system and demonstrated that continuous crystalline films are formed within minutes in an ethylene glycol solution without the need for thermal annealing or external metal precursors. The mechanistic investigation revealed that the plasma-liquid-solid interface functions as a unique reaction field providing a dual driving force. The plasma treatment induced a reaction by functioning as an electrochemical driver for anodic metal dissolution while simultaneously assisting in ligand deprotonation through the generation of reactive species such as hydroxyl and superoxide ions. This process is governed by a kinetic balance, where a specific processing window defined by the metal electrode potential and the ligand acidity distinguishes copper from other metals. These results indicate that atmospheric pressure plasma serves as a potent tool for interfacial coordination chemistry, provided that the electrochemical ion supply and acid-base kinetics are synchronized. This work establishes a design principle for the rapid and additive-free fabrication of MOF films, thus offering a foundation for the streamlined integration of functional porous layers into next-generation devices.

All-solid-state batteries (ASSBs) have attracted attention as next-generation energy storage systems by their thermal stability and higher-energy-density potential. However, thick solid electrolytes in conventional ASSBs remain a key bottleneck, simultaneously increasing stack thickness and limiting ion-transport efficiency. Here, we develop a hybrid ASSB by depositing a thin-film electrolyte on a bulk anode substrate and stacking a thick cathode sheet. The thin-film electrolyte was deposited by co-sputtering with a Li2O capping layer. After thermal annealing in Ar, it formed a pure cubic-phase Li6.4La3Zr1.4Ta0.6O12 film with a uniform thickness of 2.5 µm and an out-of-plane Li-ion conductivity of 1.91 × 10-2 mS cm-1 at room temperature. A pore-gradient, well-compacted anode substrate (9.01% porosity) was fabricated via high-speed mixing and cold pressing, followed by thin-film sputtering deposition and infrared-based rapid annealing to integrate the bulk substrate and the thin-film electrolyte. A hybrid ASSB employing a 60 µm-thick cathode sheet exhibited stable cycles, delivering an initial charge capacity of 102.96 mAh g-1 and a discharge capacity of 52.59 mAh g-1, while maintaining a robust electrode-electrolyte interface after cycling. This work demonstrates the successful operation of a hybrid architecture, offering a new design strategy that integrates bulk electrodes with thin-film electrolytes toward high-energy-density ASSBs.

Van der Waals heterojunctions (vdWHs) present a promising platform for ultrathin optoelectronics, yet their performance is often limited by weak and non-uniform interlayer coupling. Here, we systematically explore the thermal annealing strategy for enhancing interface coupling and improving detection performance. Multiscale characterizations demonstrate that annealing effectively eliminates interfacial residues, reduces lattice strain, and decreases interlayer spacing. These structural optimizations enhance wavefunction overlap, promote interlayer charge transfer, and strengthen the built-in electric field, as evidenced by Raman spectroscopy, photoluminescence (PL), and Kelvin probe force microscopy (KPFM). Consequently, the optimally annealed device (500 °C) exhibits a remarkable increase in photocurrent (Iph) from 3.9 × 10-6 A to 2.0 × 10-4 A, with responsivity (R) rising from 11 to 564 A/W. This improvement is accompanied by an external quantum efficiency (EQE) of 1.3 × 105%, a detectivity (D*) of 3.6 × 1011 Jones, and the response rise/fall time of 4.7 ms/3.6 ms at a bias of 1 V. Under zero-bias operation, the device maintains a self-powered photoresponse with an Iph of 7.01 × 10-8 A and R of 0.195 A/W. This work elucidates the underlying mechanism by which thermal annealing strengthens vdWH interfaces and provides a practical, scalable approach for achieving high-performance next-generation optoelectronic applications.

We present a systematic study of how thermal annealing (450-1000°C) affects optical propagation loss in low-pressure chemical vapor deposited (LPCVD) stoichiometric silicon nitride (Si3N4) thin films and waveguides at visible wavelengths. Slab-mode characterization using prism coupling shows that the loss remains within measurement uncertainty up to annealing temperatures of ∼900°C, above which it increases sharply at all measured wavelengths. After accounting for modeled scattering, the residual loss is consistent with an absorption-like increase of 11.1 ± 1.48 dB/cm at 447 nm following 975°C annealing. This behavior is corroborated by measurements on high-confinement waveguides. For the Si3N4 stack investigated here, annealing above 900°C substantially increases visible-wavelength propagation loss, highlighting a trade-off between infrared-optimized annealing and visible performance.

van der Waals (vdW) two-dimensional (2D) materials are pivotal for advancing high-performance electronic and optoelectronic devices in the post-Moore era. However, their practical performance is severely limited by interface quality, which poses a critical bottleneck. Herein, we systematically investigate the electrical response of vdW interfaces under electric fields, thermal annealing, and alternating current excitation, thereby establishing a theoretical basis and technical pathway for interface optimization. Specifically, using peak force tunneling amperemeter (TUNA) atomic force microscopy (AFM), we directly observe that interface bubbles impede interlayer carrier transport in vdW heterostructures. Furthermore, thermal annealing investigations reveal a non-monotonic modulation of the rectifying behavior in the heterostructure. Additionally, electric field distribution simulations provide insights into the mechanisms for the attenuation or screening of vertical electric fields across various vdW interfaces. Overall, this work offers a rigorous, actionable framework integrating physical insights and application needs, with significant implications for precise interface design, optimized thermoelectric processing windows, and reliable integration of wafer-scale 2D material devices.

Interplay of Surface Morphology and Thermal Annealing on the Multifunctional Performance of Amorphous CoFeBGd Thin Films

ABSTRACT Wavelength‐tunable nanolasers, critical for manipulating light‐matter interactions, are typically achieved by electrical, mechanical, or thermal approaches. Here, we demonstrate a chemical strategy for tunable nanolasing via refractive index (RI) modulation in 2D Ti 3 C 2 T x MXene nanoparticle (NP) lattices. The Ti 3 C 2 T x colloidal solution is coated into a film and then patterned into NP lattices by nanoimprint and dry etching. Employing these lattices as the distributed feedback (DFB) cavities and dye solutions as the gain medium, we realize room‐temperature dual‐mode lasing emission at 443 and 452 nm, which correspond to the upper and lower band edges, respectively. Furthermore, the intercalation and deintercalation through solution immersion and thermal annealing are developed to effectively modify the surface terminations and interlayer environment of Ti 3 C 2 T x and shift the RI of cavities. This leads to variations in the resonant wavelength and a 5 nm reversible tuning of the lasing emission. Our work presents a new chemical perspective for applying 2D materials to tunable nanolasers and is promising for applications such as imaging, chem/bio‐sensing, and optical display.

As a promising candidate for flexible and portable photovoltaic devices, all-polymer solar cells (all-PSCs) have recently garnered significant attention in the field of organic photovoltaics. However, due to the unfavorable morphology and weak crystallinity caused by complex chain entanglement within all-polymer systems, the power conversion efficiencies (PCEs) of all-PSCs still lag behind those of small-molecule-acceptor-based organic solar cells. Given that conventional thermal annealing (TA) lacks sufficient control over the crystallization and vertical distribution of polymer acceptors, we developed an innovative wet-assisted annealing (WAA) strategy. By leveraging the selective dissolution and volatilization effects of assist solvents during the thermal annealing process, the vertical distribution of donors and acceptors in bulk heterojunction (BHJ) structures were finely optimized. More importantly, this strategy enhances the molecular stacking of polymer acceptor, and achieves well-defined fibrillar network morphology. Benefiting from this approach, the PM6:PY-DT-based binary all-PSCs achieved a record PCE of 20.04% with enhanced stability, significantly exceeding the performance of conventional TA-processed devices. Meanwhile, the WAA strategy demonstrated consistent effectiveness across different batches of the polymer acceptor, underscoring its robustness and practical value for fabricating high-efficiency and stable all-PSCs.

Fully vacuum-evaporated perovskite solar cells (PSCs) offer a solvent-free, scalable platform for indoor photovoltaics, yet performance is often limited by incomplete phase conversion and high defect densities. Here, we report a sequential vacuum-evaporation strategy that enables the formation of high-quality perovskite absorbers specifically optimized for low-intensity indoor light harvesting. By co-evaporating PbI2 with a controlled fraction of PbCl2, the dense stacking characteristic of thermally deposited PbI2 is effectively disrupted, promoting homogeneous organic-inorganic interdiffusion and near-complete perovskite phase conversion. Additionally, a thin CsI interlayer introduced prior to thermal annealing stabilizes the photoactive phase and suppresses defect formation at both the bulk and interfacial levels. Consequently, the optimized fully evaporated PSCs deliver record indoor power conversion efficiencies of 41.60% at 900 lux and 41.22% at 300 lux under TL84 illumination. Transient photovoltage and photocurrent analyses reveal prolonged carrier lifetimes and accelerated charge extraction, indicative of substantially reduced nonradiative recombination. Importantly, the devices exhibit markedly enhanced operational stability and enable a perovskite mini module (3.9 cm2), achieving over 38% efficiency at 900 lux under indoor lighting. Collectively, this work establishes a practical and industrially compatible pathway toward high-performance, scalable, fully evaporated perovskite photovoltaics, advancing their deployment in next-generation self-powered indoor electronic systems.

Triptycene derivatives bearing long alkoxy chains at the 1,8,13- or 1,8-positions have been demonstrated to self-assemble on solid substrates into highly ordered thin films featuring a two-dimensional (2D) nested hexagonal packing of the triptycene moieties and a one-dimensional (1D) stacking layer. Although the bulk-phase structures of these derivatives have been clarified, the molecular-level mechanism governing their assembly near solid interfaces remains elusive. Here, we performed all-atom molecular dynamics (MD) simulations to investigate three triptycene derivatives (Trip1, Trip2, and Trip3) with different alkoxy-chain substitution patterns, revealing their assembly structures, thermodynamic stabilities, and interfacial ordering processes. Our simulations showed that antiparallel molecular alignment is thermodynamically stable in bulk assemblies, whereas thin films preferentially adopt a parallel alignment, indicating that solid interfaces promote this orientation. Furthermore, thermal annealing of stair-stepped trilayers drove their transformation into flat bilayers and the growth of hexagonally ordered domains, quantified by radial distribution functions and hexatic order parameters. Comparative analysis demonstrated that alkoxy substitution patterns dictate packing density, structural order, and phase stability, in excellent agreement with experimental observations. These findings provide molecular-level insights into interface-driven self-assembly and establish design principles for constructing thermodynamically stable, highly ordered organic thin films, enabling simulation-guided strategies for next-generation nanoscale materials design.

Abstract A series of Mg-doped multilayered hBN films were prepared by atmospheric chemical vapor deposition. Transmission line method measurements were performed using Ti/Ni, Ti/Au, and Ti/Pt ohmic metals. The impact of rapid thermal annealing is investigated at 650, 850, and 1000 ℃, and the measured current increases with each anneal step. The Ti/Pt scheme yields a current of 82 µA, 330 µA, and 1.9 mA after consecutive 650, 850, and 1000 ℃ rapid thermal anneals, respectively. The p-hBN channel current density is 31.6 µA µm -1 for a 10 µm channel spacing at 10 V and is comparable to other p-type two-dimensional semiconductors. For Ti/Ni, Ti/Au, and Ti/Pt, we report a contact resistance of 498.8, 241.7, and 38.3 kΩ µm, respectively, after a 1000 ℃ rapid thermal anneal and a low bulk resistance of 18 mΩ cm. Hall effect analysis confirms that the samples are p-type with an initial sheet carrier density of 5.6×10 11 cm -2 .

The atomic microstructural evolution of circumstellar dust grains, which seed the interstellar medium, remains poorly understood. Amorphous alumina and its crystalline polymorphs, including corundum, have been found in the circumstellar shell of evolved stars. Evidence includes both astronomical observations of mid-infrared spectroscopic features and laboratory analyses of presolar grains. In this work, we show that electron fluxes can stimulate crystallization of amorphous alumina stardust analog materials using transmission electron microscopy. Crystallization experiments conducted at varying electron energies and flux conditions demonstrate a critical threshold cumulative electron dose of ∼1024 e-/m2 for crystallization, suggesting that the crystallization process can occur through atomic rearrangement due to electron interaction with the amorphous matrix. Throughout the crystallization process, time-resolved diffraction reveals the transition from amorphous to a transitional η-Al2O3 phase. The same transitional phase was confirmed to occur via thermal annealing at 800 °C, while annealing at 1,300 °C produced the stable crystalline phase α-Al2O3 (corundum). In both processes, the structural evolution through atomic rearrangement was characterized by quantifying the average interatomic distance between neighboring atoms using the electron pair distribution function analysis. Extrapolating to astronomical timescales, our findings suggest that electron bombardment may play a significant role in the crystallization of stardust grains, highlighting its potential importance in astrophysical environments, such as the circumstellar envelopes of planetary nebulae.