Employing both theoretical modeling and experimental measurements, we investigate the impact of electron-hole puddles on two-dimensional (2D) carrier transport in ultrathin field-effect transistors. The electron-hole puddles are caused by charged impurities that are inevitably present in the device environment. We propose a theoretical model quantifying potential fluctuations induced by residual electric charges and analyze their effects on carrier density and density of states. Combining both Boltzmann transport theory and self-consistent effective-medium theory, the calculated conductivity shows excellent agreement with experimental data from inhomogeneous PtSe 2 systems. Our findings show that electron-hole puddles lead to reduced mobility, threshold gate voltage shifts, and enhanced minimum conductivity, and these effects become particularly pronounced in systems with thin conducting channels. It reveals that the electron-hole puddles play a crucial role near band edges — regions typically characterized by low carrier density where the variations in the local potential induce a complex admixture of electron and hole transport under specific gate biasing. Furthermore, as the layer thickness increases, the potential fluctuations caused by surface impurities diminish, and we identify a transition from inhomogeneous to homogeneous transport. This study provides a comprehensive framework applicable to various 2D material systems, offering valuable insights for optimizing ultrathin electronic devices.

Transition metal dichalcogenides (TMDs) with tunable dendritic fractal geometry offer a powerful strategy to engineer their electronic and catalytic properties. However, the fundamental understanding of how such morphological complexity governs intrinsic carrier transport-critical for optoelectronic devices-remains elusive. Here, we investigate the photocarrier dynamics of polymorphic WS2 homostructures formed by dendritic overlayers and compact monolayers, and demonstrate that the exciton transport in pristine TMD can be effectively improved by introducing p-type doping in dendritic TMD overlayer. Transient absorption spectroscopy reveals that the photocarrier lifetime is prolonged eightfold in the polymorphic homostructures compared to that of pristine compact monolayers. This is attributed to enhanced carrier separation by the built-in electric field formed at the p-n homojunction interface due to ground-state hole transfer, as established by electrostatic force microscopy (EFM). Transient absorption microscopy further confirms that the transferred carriers in homostructures exhibit faster interfacial diffusion, yielding a diffusion coefficient of approximately 180 cm(2) s(-1) at room temperature. This value not only surpasses that of the compact monolayer (similar to 100 cm(2) s(-1)) but also exceeds those of most previously studied 2D semiconductors. These results offer valuable insights for the development of high-mobility ultrathin TMDs for applications in solar cells, light-emitting diodes, and photodetectors.

Conventional vision systems encounter data bottlenecks and high-power consumption in emerging applications due to the separation of sensing and computation. In-sensor computing architectures address this limitation by integrating reconfigurable, self-powered photodiodes at the pixel level to enable in-situ visual preprocessing. However, existing devices are constrained by high programming energy, poor weight retention, or complementary metal-oxide-semiconductor (CMOS) incompatibility, hindering simultaneous optimization of power efficiency, speed, stability, and integrability. Here, we demonstrate a self-powered reconfigurable photodiode based on a bipolar WSe2 channel and a sub-20-nm ferroelectric HfxZr1-xO2 (HZO) layer. The device employs a split-gate architecture to generate polarity-switchable short-circuit photocurrent under photovoltaic mode, achieving ultralow programming energy (< 1 fJ), a switching speed of 50 mu s, and weight retention exceeding 100 s. When deployed as a physical convolution kernel, the device performs in-sensor matrix-vector multiplication on incident light. In simulated edge-detection tasks, it achieves a remarkably low normalized mean squared error (similar to 3.2 x 10(-4)), producing edge maps nearly indistinguishable from ideal software results. This work establishes an energy-efficient and self-driven hardware platform that unifies sensing, memory, and computation, realizing a practical framework for in-sensor computing.

The practical application of aqueous supercapacitors is constrained by the balance between cycle life and power characteristics. This study develops a composite electrode based on hexagonal boron nitride/carbon nanotubes (h-BN/CNTs), featuring fabrication processes through thermal annealing and electrostatic assembly. The material ingeniously combines the chemical inertness and structural stability of h-BN with the conductive network of CNTs, successfully constructing an electrode with highly stable mechanical and electrochemical interfaces. The assembled symmetric supercapacitor demonstrates excellent long-term operational reliability, maintaining over 90% stability after 10,000 charge-discharge cycles while exhibiting outstanding rate performance. The core value of this work lies in its application to h-BN platforms for high-power, high-frequency optical devices, successfully transforming it into a high-performance electrochemical energy storage component. The material has a high power density of 600 W/kg and a fairly good energy density of 13.6 Wh/kg in the symmetric two-electrode test. This device construction strategy based on a unified core material system creates compatibility advantages for material substrate and process-level integration with high-power optical devices, providing a material foundation for developing next-generation optoelectronic integrated systems.

The development of radiative cooling materials through colloidal particle assembly methods represents a promising advancement in thermal management through spectral control. In this work, a cuboid-patterned array of SiO2 nanorods is proposed to form hyperbolic metamaterials with slow-light waveguiding behavior. The SiO2 nanorods are vertically assembled into three-dimensional arrays and coated with aluminum-doped zinc oxide (AZO) on their inner surfaces via atomic layer deposition, resulting in effective indefinite dielectric properties-i.e., hyperbolic dispersion-in the infrared regime. Due to the bulk plasmonic resonance of AZO in the infrared range, determined by its doping level, a relative group velocity vg/c as low as one-thousandth can be achieved within the 3-10 & micro;m wavelength range, offering what we believe to be a novel route to enhance infrared emissivity. Furthermore, the fabricated structure exhibits an average emissivity of 84.7% in the 8-13 & micro;m atmospheric window and a low average absorptivity of only 14.6% in the full solar spectrum. Both the experimental results and the electromagnetic simulations confirm the structural potential for daytime radiative cooling. (c) 2026 Optica Publishing Group. All rights, including for text and data mining (TDM), Artificial Intelligence (AI) training, and similar technologies, are reserved.

The development of efficient, stable and commercially viable photocatalysts for reducing toxic Cr(VI) is of vital importance to environmental governance. In this work, we prepared a series of novel 2D/3D hierarchical ZnIn2S4/La2Ce2O7 (ZIS/LCO) heterojunctions via an in situ hydrothermal method. The optimal composite (ZL-1) demonstrated high photocatalytic activity, removing 91.5 % of Cr(VI) within 90 min. Which is 7.6 times and 259 times than that of pure ZIS and LCO, respectively. Moreover, ZL-1 maintained good stability across multiple recycling tests. Characterization data reveal that the composite structure offers a larger contact interface, improved light absorption, and effective heterojunction formation, which together boost charge separation and migration at the interface, leading to high catalytic stability and practical performance. Combining band structure analysis, active species trapping experiments and DFT calculations, the phenomenon is caused by the Sscheme heterojunction, namely the effective band misalignment and the push of the internal electric field (IEF), thereby eliminating useless carriers and accumulating strong electrons in the LCO conduction band and ZIS valence band for redox reactions. This study proposes a promising strategy for applying La2Ce2O7 in the field of environmental purification Cr(VI).

Flexible supercapacitors have garnered significant attention in the research of flexible energy storage devices in recent years due to their advantages of rapid charging and discharging capabilities, long cycle life, high power density, and outstanding mechanical flexibility. Manganese dioxide (MnO2) has a high theoretical specific capacitance (1370 F g-1) and high crystal phase and morphology tunability, but low conductivity limits performance. Hydrothermal methods can customize nanostructures, but require harsh conditions and a high percentage of conductive agent and binder in the powder electrode, reducing energy density. In this study, MXene nanosheets with excellent conductivity were deposited onto flexible carbon cloth (CC, collector) via a composite fabrication strategy to fabricate MXene/CC. The MXene/CC served as a substrate for further in-situ MnO2 loading through a mild solution immersion process under ambient conditions. After optimization, the MnO2 micro-spheres formed after 8 immersions exhibited the superlative performance. Notably, this method is environmentally benign, easy to operate, and free of conductive agents or binders. The MnO2@MXene@CC-8 (MMC-8, obtained by 8 immersion cycles) positive electrode exhibited a specific capacitance of 234.8 F g-1 at 1 A g-1 in a neutral electrolyte (0.5 M Na2SO4), while the MMC-8//MC asymmetric flexible supercapacitor, employing MXene@CC (MC) as the negative electrode, achieved a capacitance of 21.3 F g-1 at 1 A g-1 with 75 % capacitance retention after 10000 cycles. The device demonstrated an energy density of 9.6 Wh kg-1 at a power density of 902.3 W kg-1. This strategy provides new insights into the scalable fabrication of flexible supercapacitors.

Dynamic vision processing at the edge requires in-sensor spiking neural networks (SNNs) to achieve high energy efficiency and rapid processing. Although optoelectronic leaky integrate-and-fire (LIF) neurons are essential for optical sensing and sparse coding, their practical utility has been hindered by incomplete emulation of biological behaviors and integration difficulties with synaptic devices. Here, we show an optoelectronic LIF neuron based on a MoS2 phototransistor that reproduces key neuronal features, including multispectral sensing, capacitor-less integration, and threshold-triggered spiking. This neuron supports complementary rate and time-to-first-spike coding, enabling versatile visual information processing at the hardware level. Furthermore, we achieve the homogeneous integration of these neurons with MoS2 ferroelectric synapses on a single substrate, unifying volatile optical encoding with non-volatile weight storage. The integrated SNN system attains recognition accuracies of 91.7% for color recognition and 93.5% for object detection, indicating its potential for scalable, high-performance next-generation neuromorphic vision systems.

Microspheres dispersed in composites exhibit excellent infrared emissivity for radiative cooling applications, which reflect sunlight and passively dissipate heat into space without electricity. In this study, hierarchical microspheres (HMs) with a two-tier structure, composed of SiO2, TiO2-coated SiO2, BaSO4, or PNIPAM, are incorporated into PDMS-based composites. These microspheres feature larger spheres assembled from submicrometer-scale nanoparticles and are fabricated via microfluidics to enhance radiative cooling performance. SiO2 HMs not only boost visible light reflection and exhibit structural color through a photonic stop band but also achieve an average emissivity of 97.55% in the atmospheric window. Both experimental and simulated results show that HMs enhance the emissivity performance of the composite material compared with solid SiO2 microspheres of the same diameter. Additionally, applying TiO2 coating to SiO2 HMs further increases the overall emissivity to 98.05%. Incorporating BaSO4 HMs also increased the average visible reflectivity to 96.56%, while maintaining superior infrared emissivity at 97.58%. The inclusion of PNIPAM spheres enabled temperature-responsive transmissivity, with the composite materials containing PNIPAM and SiO2 HMs preserving high infrared emissivity in the atmospheric window. These HM structures exhibit excellent solar reflectivity and thermal emission, making them effective for radiative cooling.

van der Waals ferroelectric field-effect transistors (FeFETs) hold great promise as next-generation volatile memory and neuromorphic devices. However, their performance is significantly influenced by defects introduced during the fabrication process and interfacial effects in two-dimensional (2D) materials. Moreover, operando measurement of key parameters such as carrier mobility and diffusion length in these micro- and nanodevices remains challenging. To address these challenges, we have developed an electrically coupled spatiotemporally resolved pump-probe device that enables nondestructive measurement of carrier diffusion and relaxation processes in FeFETs under operating conditions. Spatially resolved measurements on a single WSe2 flake under both ferroelectric and metal gate configurations demonstrate that the ferroelectric gate exerts a highly efficient modulation on the carrier mobility of WSe2, attaining a carrier mobility/voltage modulation ratio of up to 749.50 cm2/V2s. This significantly outperforms the modulation achieved with a metal gate, which stands at 575.98 cm2/V2s. This finding provides strong direct evidence for the electrostatic doping theoretical model in thin-film transistors. Additionally, compared to the WSe2 above the metal gate, the carrier recombination lifetime of WSe2 above the ferroelectric gate is extended by approximately 10 times, suggesting that the volatile weight modulation mechanism in such neuromorphic devices may originate from changes in carrier lifetime. This operando nondestructive measurement technique is poised to deliver a substantial value in advancing the development and optimizing the performance of next-generation two-dimensional transistors.

Two-dimensional materials possess exceptional optoelectronic properties, including high carrier mobility and tunable bandgaps, making them highly suitable for various electronic and optoelectronic applications. While inorganic 2D materials exhibit ultrafast and efficient interlayer charge transport, they suffer from limited light absorption capabilities. In contrast, organic semiconductors offer broad spectral absorption but are constrained by their inherently low charge carrier mobility. Conjugated polymers such as poly(3-hexylthiophene) (P3HT) exhibit excellent mechanical flexibility, solution processability, and film-forming capabilities, enabling the scalable fabrication of high-performance flexible optoelectronic devices. To overcome these limitations, we successfully developed a type-II MoSe2/P3HT heterostructure (HS) that combines the complementary advantages of both material systems. Steady-state absorption measurements reveal that the MoSe2/P3HT HS exhibits both broader spectral coverage and stronger absorption intensity compared with its individual components. Photoluminescence (PL) spectroscopy studies demonstrate significant PL quenching in the HS, suggesting efficient interfacial charge transfer between the constituent layers. Transient absorption spectroscopic results reveal efficient interfacial hole transfer from MoSe2 to P3HT with a time scale of 19.9 ps. Notably, the MoSe2/P3HT heterostructure exhibits an exceptionally slow charge recombination lifetime of 901.4 ps, significantly surpassing that of inorganic-inorganic van der Waals heterostructures. Organic-inorganic hybrids demonstrate enhanced light absorption, ultrafast charge transfer, and prolonged carrier lifetimes, rendering them highly promising for high-efficiency photovoltaics, broadband photodetectors, and other advanced optoelectronic applications in the future.

Understanding and controlling interlayer charge transfer is critical for advancing the performance of van der Waals (vdW) heterostructures in optoelectronic applications. Despite extensive studies demonstrating ultrafast charge transfer across vdW interfaces, the microscopic mechanisms remain under debate. Here, we report an experimental test of phonon-assisted interlayer charge transfer using a MoSe2/MoSSe/MoS2 trilayer heterostructure. By inserting an alloy MoSSe monolayer between MoSe2 and MoS2, we demonstrate that the electron transfer process becomes significantly faster than in a direct MoSe2/MoS2 bilayer, despite increased spatial separation and reduced band offsets. This result provides support to the phonon-assisted charge transfer model, where the alloy layer enhances phonon-assisted charge transfer from MoSe2 to MoS2 layers by offering compatible phonon modes. This finding also offers a new design principle for controlling ultrafast processes in vdW heterostructures and demonstrates that alloy engineering is a powerful strategy to modulate interfacial interactions and unlock novel functionalities in vdW heterostructures.

A doping-based strategy is presented to control interlayer charge transfer in transition metal dichalcogenide/graphene heterostructures. In a system combining monolayer graphene with Nb-doped MoSe2, a built-in electric field forms at the interface due to ground-state hole transfer. This field effectively suppresses the transfer of photoexcited holes while allowing electrons to move into the graphene layer, resulting in unipolar electron injection. Transient absorption spectroscopy reveals a prolonged carrier lifetime of approximately 180 picoseconds in the doped heterostructure, compared to only a few picoseconds in the undoped case. Transient absorption microscopy confirms that the transferred carriers exhibit fast in-plane diffusion in graphene, consistent with high mobility and free carrier transport. This approach enables precise tuning of photocarrier dynamics and provides a general framework for designing van der Waals heterostructures with enhanced optoelectronic performance, suitable for applications such as photodetectors and ultrafast optical devices.

The optical response manipulation of two-dimensional materials is crucial for designing and optimizing high-performance optoelectronic devices. Previously, optical modulation in two-dimensional semiconductors primarily relied on adjusting carrier density through optical excitation or charge injection using the energy band-filling effect. Recently, twist angle has been found to tune the optical and optoelectronic properties of van der Waals structure, but its impact on the transient optical response remains unexplored. Herein, we demonstrate that twist angle can effectively regulate carrier behaviors by tracing the evolution of optical responses in twisted bilayer WS2from 0° to 60°. Both Raman and PL spectra consistently show that the optical responses of WS2bilayers are highly dependent on the twist angle. Exciton behavior and phonon modes exhibit similarity at twist angles near 0° and 60°, but significantly change as the angle approaches 30°. Moreover, the impact of the twist angle on the transient optical responses was carefully investigated using a femtosecond pump-probe technique. The results reveal a significant decrease in carrier thermalization/relaxation time and exciton formation/recombination time at the WS2bilayers with twist angle of ∼31.0°, as compared to twist angles of ∼2.9° and ∼58.9°, which can be attributed to the accumulation of intralayer carriers due to weakened interlayer coupling. These results demonstrate that twist angle can effectively modulate the optical response of twisted 2D materials. Our study elucidates the dynamic carrier behavior in twisted bilayer WS2and provides new insights for designing future optoelectronic and photonic devices.

Two-dimensional (2D) transition metal dichalcogenides and their alloys provide a unique platform for exploring interlayer charge transfer in van der Waals heterostructures. These structures are crucial for advancing the next-generation electronic, optoelectronic, and quantum devices. In this study, interlayer charge transfer in heterostructures composed of MoSe2, MoS2, and their alloy, MoSSe, is investigated using transient absorption, Raman, and photoluminescence spectroscopy. The experimental results reveal that electron transfer in the alloy heterostructures, MoSSe/MoS2 and MoSe2/MoSSe, is faster than in the pure MoSe2/MoS2 heterostructure, despite the smaller conduction band offsets of the alloy systems. Raman spectroscopy confirms that alloy layers support phonon modes matching those of the pure layers, aligning with theoretical models of phonon-assisted interlayer charge transfer. Additionally, efficient hole transfer is observed in both alloy heterostructures. The findings suggest transition metal dichalcogenides alloys can be used for engineering heterostructures with desired charge transfer properties. By leveraging compositionally tunable band gaps and optical properties, alloy-based heterostructures offer opportunities for designing tailored materials suitable for diverse applications such as photodetectors, light-emitting devices, and flexible electronics. Moreover, the ultrafast charge transfer observed in these systems provides insights into the fundamental mechanisms governing interlayer interactions in 2D materials.

Supercapacitors are gaining traction in the energy storage sector due to their high power and energy density. MnO2 is identified as a promising supercapacitors electrode material due to its reversible Faraday reaction and great theoretical specific capacitance. However, its practical performance is hindered by poor electrical conductivity and structural instability. By incorporating Ti3C2Tx, a 2D MXene material known for its high conductivity and functional groups, the electrochemical behavior of the MnO2 composite is expected to be enhanced. This study introduces a novel method for synthesizing MnO2@Ti3C2Tx self-assembled electrodes (1, 3, 6, 9-MnO2@Ti3C2Tx composite electrodes) via a simple solution immersion technique at room temperature and ambient pressure. The state of manganese dioxide deposition can be influenced by varying the number of operations of the solution immersion technique. Among them, 6-MnO2@Ti3C2Tx has the largest specific surface area and achieves the best specific capacitance of 324.1 F g-1. When the current density is increased to 10 A g-1, the specific capacitance retention of 6-MnO2@Ti3C2Tx is 67.11%. Furthermore, the 6-MnO2@Ti3C2Tx//Ti3C2Tx asymmetric capacitor demonstrated a maximum energy density of 30.8 W h kg-1 and a power density of 7493.3W kg-1, maintaining a capacitance retention rate of 95.98% (from 74.6 to 71.6F g-1) after 2000 charge-discharge cycles. This study presents an effective and scalable synthesis strategy for MnO2 composite electrodes, highlighting their potential for future energy storage applications.

Hybrid excitons formed via resonant hybridization in 2D material heterostructures feature both large optical and electrical dipoles, providing a promising platform for many-body exciton physics and correlated electronic states. However, hybrid excitons at organic-inorganic interface combining the advantages of both Wannier-Mott and Frenkel excitons remain elusive. Here, hybrid excitons are reported in the copper phthalocyanine/molybdenum diselenide (CuPc/MoSe2) heterostructure (HS) featuring strong molecular orientation dependence by low-temperature photoluminescence and absorption spectroscopy. The hybrid Wannier-Mott-Frenkel excitons exhibit a large oscillator strength and display signatures of the Frenkel excitons in CuPc and the Wannier-Mott excitons in MoSe2 simultaneously through the delocalized electrons. The density functional theory (DFT) calculations further confirm the strong hybridization between the lowest unoccupied molecular orbital (LUMO) of CuPc and the conduction band minimum (CBM) of MoSe2. The out-of-plane molecular orientation is further employed to tune the hybridization strength and tailor the hybrid exciton states. The results reveal the hybrid excitons at the CuPc/MoSe2 interface with tunability by molecular orientation, suggesting that the organic-inorganic HS constitutes a promising platform for many-body exciton physics such as exciton condensation and optoelectrical applications.

Inverse opals with spherical morphologies, fabricated to accommodate a diverse range of material systems, are of significant importance for applications requiring particle-dispersed functional materials with photonic management capabilities. In this paper, hierarchical microspheres (HMs) with tier-1 diameters ranging from 5 mu m to 250 mu m, and silica or polystyrene as tier-2 microspheres of various diameters, are prepared using microfluidic methods and used as templates for spherical inverse opals. Hierarchical microsphere-based inverse opals (HMIOs), made from various individual materials such as Al2O3, TiO2, ZnO, SiO2, Bi2O3, and g-C3N4, as well as from composites like Bi2O3/g-C3N4 and Al2O3/TiO2, are obtained using atomic layer deposition, sol-gel filling, and chemical vapor deposition methods. The wavelength of the reflection peaks induced by the photonic stop band is primarily determined by the periodicity of the pores, while the reflection peak intensity in HMIOs depends on the orderliness of the pores, which increases with their primary diameter. Among the materials, Bi2O3/g-C3N4 HMIOs exhibit the best photocatalytic degradation performance due to the matched energy levels. MXene-incorporated hydrogenated TiO2HMIOs, produced through microfluidic processing, also demonstrate an enhanced photo- catalytic degradation rate, which is 1.74 times higher than that of the corresponding material without MXene.

By PDMS-assisted colloidal lithography, high-aspect-ratio microstructures were employed as the structure for the successful fabrication of broadband near-perfect optical absorbers.