A series of NiFex/CeO2 bimetallic catalysts was prepared by the incipient wetness impregnation method and subsequently applied for CO2 methanation. The CO2 methanation activity of the NiFex/CeO2 catalyst is significantly enhanced by the introduction of an appropriate amount of Fe. At 280 °C, 100 kPa and 24,000 mL/(g·h), the NiFe0.3/CeO2 catalyst exhibits a CO2 conversion of 88.6 High CO2 methanation activity was achieved over NiFex/CeO2 bimetallic catalyst, in which a strong electronic interaction exists between Fe and Ni.

Pure organic room-temperature phosphorescence (RTP) has attracted widespread attention due to its large Stokes shift and long luminescence lifetime. Gels, as synthetically produced soft materials, are known for their adsorption capacity, ease of preparation, and degradability. However, stimuli-responsive gels with controllable RTP emission were rarely reported. In this study, an RTP supramolecular gel enabling visualization of humidity-response was developed through construction of dual non-covalent interactions. Firstly, the assembly process of two molecules of the fluorescent compound (Upy3-BrBP) and cucurbit[8]uril (CB[8]) successfully induced RTP emission. Moreover, the complex could act as a crosslinker to connect disordered hydrogen-rich polymers into regularly ordered polymer networks, generating a supramolecular gel and significantly enhancing RTP leading to nearly pure RTP emission. The phosphorescence quantum yield increased sharply by a factor of 19.2, and the phosphorescence lifetime was extended by a factor of 8.6. More importantly, the formed supramolecular gel enables visualization of ambient humidity and its changes through RTP variation from shining green to dark blue. This RTP supramolecular gel offers a new strategy for the development of intelligent sensing materials with visual monitoring capability.

The data-intensive nature of the Internet of Things (IoT) significantly challenges conventional communication systems. While over-the-air computation integrates communication and computation to reduce data aggregation burdens, it requires strict synchronization of transmitted signals, increasing system overhead. Here, we report an optical in-sensor wireless data aggregation paradigm that exploits photocarrier trapping in defect-dominated persistent photoconductance sensors to reduce dependence on synchronization constraints. Within a single communication window, the system reliably aggregates incoherent optical signals with relative timing offsets exceeding the signal duration by up to 120%, while achieving computation errors below 1.5% normalized mean squared error. This process achieves unbiased integration with pulsed low-frequency readout, indicating its potential for ultra-low power operation. A distributed temperature prediction model based on this paradigm shows faster convergence and competitive accuracy with a simplified architecture, demonstrating effectiveness in distributed edge sensing scenarios. This work provides a promising hardware implementation for low-power data aggregation in large-scale IoT edge networks.

The Bingel-Hirsch (BH) reaction is a key strategy for functionalizing fullerenes and endohedral metallofullerenes, typically affording cycloadducts with reduced reactivity toward metallofullerenes. Unexpectedly, a recent experiment on TiSc2N@C80 revealed single-bond BH adducts with markedly enhanced reactivity. However, the detailed mechanism and precise adduct structures remain unclear due to limited experimental evidence. Here, we report a comprehensive density functional theory investigation of the BH reaction between TiSc2N@C80 and diethyl bromomalonate. We show that single-bond addition pathways have substantially lower free-energy barriers than cycloaddition pathways, supporting experimental observations. Moreover, single-bond addition at pentagon-hexagon-hexagon ([566]) junctions is both thermodynamically and kinetically more favorable than at hexagon-hexagon-hexagon ([666]) sites, suggesting that the experimental products correspond to [566] adducts. This regioselectivity originates from the higher relative energies of [566] intermediates, which render them more reactive toward subsequent transformations. Remarkably, the single-bond adducts feature the most reduced fullerene cage (oxidation state -7) synthesized to date. These findings clarify the origin of the BH reactivity and selectivity of TiSc2N@C80 and offer valuable guidance for future functionalization of other paramagnetic metallofullerenes.

In this paper, a novel tunneling-drift-diffusion field-effect transistor (TDDFET) is introduced with dual-doped source and asymmetric gates. In the TDDFET, the current is conducted by two mechanisms, namely the band-to-band tunneling and drift-diffusion, making the device can present an additional state between the on and off states, and very suitable for the ternary logic design. Additionally, a standard ternary inverter (STI) is also implemented based on the TDDFET and studied in detail by the aid of TCAD simulation. It turns out that the supply voltage VDD shows significant influence on the ternary inverter and the optimized value is about 3Vturn/2 in which Vturn is the transition voltage on the transfer curve. The influence of key device parameters are also studied in detail. Compared with other ternary inverters, our designed ternary inverter requiring no any immature material, passive device and multi-valued power supply, is more friendly with the CMOS platform and can make the most of the advantages of the ternary logic.

Antiferromagnetic materials with van der Waals (vdW) layered structures hold great promises for developing the next generation of electronic and optoelectronic devices, providing unique combinations of terahertz spin dynamics, ultrastability against magnetic fields disturbance, and low power consumption. Here, we demonstrate unconventional nonvolatile bistable planar Hall effect (PHE) in few-layer GdTe3, a natural vdW heterostructure consisting of metallic Te layers and antiferromagnetic (AFM) GdTe bilayers. By fully unfolding the magnetic phase diagram of few-layer GdTe3 utilizing temperature- and angle-dependent magnetotransport measurements, we identify that the nonvolatile switching of bistable PHE states is rooted in the fourfold N & eacute;el vector flipping between two perpendicular in-plane magnetocrystalline anisotropy axes, each flipping reverses the signs of the PHE state. The efficient magnetic field (H) write-in and zero-field read out of the PHE memory pave the way for 2D AFM-based spintronics such as nonvolatile information storage and logic operations.

Abstract Polar interfaces with broken inversion symmetry have garnered significant attention due to their profound influence on charge/spin distribution and propagation, leading to unconventional phenomena such as high‐mobility electron gas, polar skyrmions, and interfacial pyroelectric/pyro‐phototronic effects. Designing and controlling polar interfaces is crucial for developing advanced functional electronic devices. Here, a strategy of polar interface engineering is proposed by modulating the built‐in electric field in Schottky junctions to generate and tune the pyro‐phototronic effect in a centrosymmetric semiconductor (β‐Ga 2 O 3 ). By varying the work functions of metal electrodes and doping concentrations, the built‐in electric field is effectively controlled, enabling modulation of the effective polarization and pyroelectric coefficient. Leveraging the pyro‐phototronic effect, the Ga 2 O 3 Schottky junction‐based self‐powered photodetector achieves an ultrafast response of 0.2 µs to solar‐blind UV light, representing a 50‐fold improvement over the control device operating with the photoconductive effect. Furthermore, five optoelectronic logic gates are realized, enabled by the bidirectional pyro‐phototronic current during light switching. These findings provide a pathway for exploring novel pyro‐phototronic phenomena in polar‐interface‐engineered semiconductors and advancing ultrafast optoelectronic detection technologies.

Amorphous oxide semiconductors (AOS) are highly promising for optoelectronic devices due to their exceptional electrical properties and optical transparency. However, a significant barrier to their development is the lack of a comprehensive materials database, which hinders systematic studies and the discovery of emergent AOS materials. This study addresses this gap by constructing a dedicated database of zinc-tin-based doped oxide semiconductors (Zn-M-Sn-O) and their thin-film transistor (TFT) performance parameters, compiled from an extensive review of existing literature. Our research aims to perform a systematic analysis of the correlations between key material properties and device performance. We summarize and analyze existing Zn-M-Sn-O based optoelectronic devices, extracting key features such as material compositions, processing parameters, and performance metrics. These features are then used to construct feature vectors. By applying a machine learning algorithm to this dataset, we establish a performance prediction model for Zn-M-Sn-O TFTs. This machine learning-assisted approach allows us to efficiently screen materials and predict the optimal M element for high-performance devices. This methodology significantly accelerates the discovery and development of advanced AOS materials, paving the way for next-generation optoelectronic technologies.

Ge and GeSn materials have garnered significant attention due to their high carrier mobility and tunable band structure, making them promising candidates for low-power electronic applications. In this work, a novel ferroelectric junctionless GOI and GeSnOI transistors is presented and characterized. The initial Ge layer or Ge/GeSn structure was grown on Si substrates and later bonded and back-etched. The final layer of Ge and GeSn in (GOI and GeSnOI) with thickness of 50 nm was obtained by wet etching using a spinner tool while etchant agent was dropped carefully to etch uniformly over the Si wafer. Ge preamorphization implantation (PAI) and rapid thermal annealing (RTA) processes were employed to form the NiGe/p-Ge contact, resulting in a contact resistance as low as 0.55 × 10–8 Ω-cm2. In addition, the formed transistors show excellent characteristics. Notably, extracted mobilities of GOI and GeSnOI transistor are in range of 200–400 cm2/V·s and 500–600 cm2/V·s, respectively. Subthreshold swing (SS) of the ferroelectric transistors on GOI and Ge0.92Sn0.08OI substrates was measured to be 37.7 mV/dec and 43.7 mV/dec, respectively. Our work demonstrates a novel and reliable process of Ge-based junctionless transistors for future low-power consumption logic circuits.

Polar interfaces with broken inversion symmetry have garnered significant attention due to their profound influence on charge/spin distribution and propagation, leading to unconventional phenomena such as high-mobility electron gas, polar skyrmions, and interfacial pyroelectric/pyro-phototronic effects. Designing and controlling polar interfaces is crucial for developing advanced functional electronic devices. Here, a strategy of polar interface engineering is proposed by modulating the built-in electric field in Schottky junctions to generate and tune the pyro-phototronic effect in a centrosymmetric semiconductor (beta-Ga2O3). By varying the work functions of metal electrodes and doping concentrations, the built-in electric field is effectively controlled, enabling modulation of the effective polarization and pyroelectric coefficient. Leveraging the pyro-phototronic effect, the Ga2O3 Schottky junction-based self-powered photodetector achieves an ultrafast response of 0.2 mu s to solar-blind UV light, representing a 50-fold improvement over the control device operating with the photoconductive effect. Furthermore, five optoelectronic logic gates are realized, enabled by the bidirectional pyro-phototronic current during light switching. These findings provide a pathway for exploring novel pyro-phototronic phenomena in polar-interface-engineered semiconductors and advancing ultrafast optoelectronic detection technologies.

P2-type layered transition metal oxides are potential cathodes for sodium-ion batteries (SIBs), but they commonly suffer from severe capacity degradation owing to multiple phase transitions and Na+/vacancy ordering during the extraction/insertion process. An anionic/cationic co-doping strategy at high sodium contents is proposed to effectively achieve high-rate and long-term stability of P2-Na0.67Ni0.33Mn0.67O2. The resulting Na0.75Mg0.1Ni0.23Mn0.67O1.95F0.05 (NMNMOF) cathode delivers a reversible capacity of 116 mAh g-1 at 75 mA g-1 and maintains an initial capacity of 73% at 1500 mA g-1 after 1000 cycles. The Mg/F anionic/cationic co-doping strategy impacts the local environment of the surrounding transition metal and oxygen, regulates the electron distribution, and modifies the initial diffusion state of Na sites, enhancing the diffusion ability of Na+. Moreover, the phase transition of P2-O2 is well suppressed and the decrease in Mn3+ content greatly alleviates the Jahn-Teller effect to enhance structural stability. The full-cell devices with NMNMOF cathode and hard carbon anode demonstrate a high capacity of 80 mAh g-1 at 10 C and an excellent cycle life of over 500 cycles for applications. The anionic/cationic co-doping strategy will inspire the rational design of P2-type layered oxides and provide a new perspective for advanced SIBs.

Applications for solar-blind photodetectors (PDs) vary widely and include space communications, ozone monitoring, and more. In this study, pulsed laser deposition (PLD) and ion sputtering were employed to develop an unusual self-powered deep ultraviolet (UV) photodetector based on CuO/Ga2O3 with a Pt nanoparticles (NPs) interface. The Pt NPs interface transforms the device design from heterojunction to Schottky junction. The device features a low dark current of 83.2 fA and performs a high photo-to-dark current (I-photo/I-dark) ratio of 1.72 x 10(4), a specific detectivity (D*) of 9.98 x 10(11) Jones, and a quick decay time of 56 ms upon 254 nm UV light at 196.5 mu W/cm(2) without any power supply. The CuO/Pt/Ga2O3 Schottky junction-based device outperforms the CuO/Ga2O3 heterojunction-based device in terms of detection capabilities in both biased and non-biased settings. This is explained by the Schottky barrier creation mechanism with both Ga2O3 and CuO films, as well as how the plasmon resonance effect (PR effect) balances the barrier on the Ga2O3 side. Furthermore, Pt NPs serve as a potential well, offering an additional recombination channel that accelerates the decay process when the light is turned off. Our findings pave the way for more optoelectronic uses of Ga2O3-based solar-blind UV photodetectors in the future.

Brain-inspired neuromorphic sensory devices play a crucial role in addressing the limitations of von Neumann systems in contemporary computing. Currently, synaptic devices rely on memristors and thin-film transistors, requiring the establishment of a read voltage. A built-in electric field exists within the p-n junction, enabling the operation of zero-read-voltage synaptic devices. In this study, we propose an artificial synapse utilizing a ZnO diode. Typical rectification curves characterize the formation of ZnO diodes. ZnO diodes demonstrate distinct synaptic properties, including paired-pulse facilitation, paired-pulse depression, long-term potentiation, and long-term depression modulations, with a read voltage of 0 V. An artificial neural network is constructed to simulate recognition tasks using MNIST and Fashion-MNIST databases, achieving test accuracy values of 92.36% and 76.71%, respectively. This research will pave the way for advancing zero-read-voltage artificial synaptic diodes for neural network computing.

Optical synapses offer a promising solution to the high energy consumption of von Neumann architectures. Despite significant research, existing photoconductivity modulation methods are typically unidirectional, and inhibitory behavior still depends on electrical stimulation. To address this, a two-terminal planar fully optically modulated synapse device based on a ZnAlSnO/SnS heterostructure, demonstrating bidirectional optical response is presented. This device exhibits an excitatory postsynaptic current (EPSC) when exposed to 370 nm UV light and generates an inhibitory postsynaptic current (IPSC) under 630 nm red light. Continuous potentiation and depression stimuli reveals the stability of fully optically modulated artificial synapses. Leveraging its fully optically modulated conductance, a three-layer artificial neural network is implemented for handwritten digit and clothing recognition, achieving accuracies of 91.12% and 78.22%, respectively. Additionally, based on its unique electrical response to UV light pulse, the development process of the Polaroid camera is well simulated. This work not only enriches the content of optical synapses, but also contributes to advancements in artificial intelligence, brain-like computing, and image-processing technologies.

Abstract The path to searching for sustainable energy has never stopped since the depletion of fossil fuels can lead to serious environmental pollution and energy shortages. Using water electrolysis to produce hydrogen has been proven to be a prioritized approach for green resource production. It is highly crucial to explore inexpensive and high‐performance electrocatalysts for accelerating hydrogen evolution reaction (HER) and apply them to industrial cases on a large scale. Here, we summarize the different mechanisms of HER in different pH settings and review recent advances in non‐noble‐metal‐based electrocatalysts. Then, based on the previous efforts, we discuss several universal strategies for designing pH‐independent catalysts and show directions for the future design of pH‐universal catalysts.

Solar-blind photodetectors based on gallium oxide (Ga2O3) have shown possibilities in optical imaging, spatial communication, and other fields. The high oxygen vacancy (VO) content inherent in Ga2O3 film would inevitably result in poor photoelectric detection capability. This work suggests using a codoping for reducing VO concentrations in Ga2O3 films. In a N2O atmosphere, magnesium and nitrogen codoped gallium oxide (Mg-N:Ga2O3) films were grown using the pulsed laser deposition (PLD) technique on (0001) sapphire substrates. It is possible to produce codoped Ga2O3 thin films with low oxygen vacancy density and high crystalline quality by thoroughly examining and optimizing preparation conditions. Metal-semiconductor-metal (MSM) photodetectors were constructed using both pristine and Mg-N codoped Ga2O3 thin films as the active layer. The photodetector with a codoped active layer outperforms those with pristine Ga2O3, with a quick decay time of 20 ms, a high sensitivity of 2.61 x 105, and a high responsivity of 0.191 A/W under 254 nm UV light irradiation, highlighting the significance of the VO concentration decrease in the application of Ga2O3-based solar-blind photodetectors.

The hydrogen evolution reaction (HER) is a cathodic reaction of water splitting which is crucial in energy conversion. However, its wide-scale industrial applicability is limited by the slow reaction kinetics and complex diffusion of generated gas bubbles. In this study, we chose the readily available, low-cost stainless steel as a conductive substrate and feasibly in-situ developed the active phase ZnIn2S4 and Ni-doped ZnIn2S4 on it as a high-rate cathode for HER in acidic, alkaline, and neutral conditions. The Ni-doped electrocatalysts, when compared to bare ZnIn2S4, have higher electrocatalytic activity for HER, with low overpotentials of only 259 mV and 224 mV, to generate a high current density of 100 mA cm(-2) in 0.5 M H2SO4 and 1 M KOH, respectively, exhibiting obviously enhanced performance. The presence of Ni atoms is evident in EDS mapping, TEM analysis, and ICP technique. A detailed analysis of the electrochemical characteristics of the generated electrocatalysts was carried out to gain a better understanding of the effect of additional doping atoms. We not only demonstrate a feasible method for developing unique, stable and efficient HER electrocatalysts in all pH settings by comprehending the collaborative effect of the active phase, doped Ni atoms, and affordable stainless-steel substrate, but also point out new avenue to branch out self-standing HER electrocatalyst categories.

The existing approach of preparing hydrogen through electrocatalytic water splitting is hindered by several factors, including the scarcity of efficient electrocatalysts for the hydrogen evolution reaction that can function well under a variety of pH settings. The development of compounds with diverse active ingredients could contribute to the heterostructured electrocatalysts' ability to effectively react with a range of reactants. Moreover, assembling active species on a substrate to produce self-supported electrocatalysts can reduce the need for electricity. Here, we utilized nickel foam as the conductive substrate to produce heterostructured electrocatalysts with active species of ZnIn2S4, Ni2P, and NiS (denoted as ZnIn2S4/Ni2P/NiS@NF). The ZnIn2S4/Ni2P/NiS@NF only needs tiny overpotentials to drive high current densities and can be operated with long-term operational durability across a broad pH range.

2D-layered materials are recognized as up-and-coming candidates to overcome the intrinsic physical limitation of silicon-based devices. Herein, the coexistence of positive persistent photoconductivity (PPPC) and negative persistent photoconductivity (NPPC) in SnSe thin films prepared by pulsed laser deposition provides an excellent avenue for engineering novel devices. It is determined that surface oxygen is co-regulated by physisorption and chemisorption, and the NPPC is attributed to the photo-controllable oxygen desorption behavior. The dominant behavior of chemisorption induces high stability, while physisorption provides room for adjusting NPPC. A simple fully light-modulated artificial synaptic device based on SnSe film is constructed to operate various synaptic plasticity and reversible modulation of conductance by applying 430 and 255 nm illuminations. A three-layer artificial neural network structure with a high accuracy of 95.33% to recognize handwritten digital images is implemented based on the device. Furthermore, the pressure-related cognition response of humans while climbing and the foraging and recognition behaviors of anemonefish are mimicked. This work demonstrates the potential of 2D-layered materials for developing neuromorphic computing and simulating biological behaviors without additional treatment. Furthermore, the one-step method for preparation is highly adaptable and expected to realize large-area growth and integration of SnSe-based devices.

—In this paper, a reconfigurable field-effect transistor (RFET) with dual-doped nanosheet architecture and triple independent gates is proposed and studied with the numerical simulations. The proposed RFET can behave as either an n/p-type MOSFET or an n/p-type tunneling-FET (TFET) according to different program biases. A comprehensive study is carried out on the device mechanism and the influence of key device parameters. Various metrics, such as the on-state current (ION), off-state current (IOFF), ION/IOFF, threshold voltage (VT) and sub-threshold swing (SS), are used to evaluate the proposed RFET. This RFET combining the advantages of the conventional MOSFETs (High ION and operation speed) and the new emerging TFETs (Low IOFF, sub-threshold swing and power dissipation) could make the circuit design more flexible and high efficiency, and improve the circuit performance.