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Owing to the increasing demand for monitoring harmful toxic gases using small‐sized low‐power‐consumption gas sensors, a room‐temperature wireless complimentary gas sensor incorporating layered materials is proposed and demonstrated. The compact design allows the sensing module to be installed under all conditions and facilitates multiple detections of toxic gas. Highly chemical‐resistance‐sensitive materials based on n‐type SnSe2 and p‐type PtSe2 layered materials prepared by the plasma‐assisted chemical vapor reaction (PACVR) method at low temperatures are integrated with an oscillation circuit and antenna fabricated by a 28‐nm CMOS high‐k metal gate logic process to achieve dense, low‐powered, and wireless characteristics. By pairing n‐ and p‐type layered semiconductors, the gas sensors feature less influence from the surroundings, such as temperature and humidity, and enhance sensitivity to the target gas simultaneously. The wireless sensing detection method enables a sensor to make signal reception more convenient. Furthermore, a wireless gas sensor with self‐converging calibration using the advantage of a floating‐gate (FG) transistor to control the charge quantity by shifting the threshold voltage (Vth) of each transistor via the channel hot electron injection effect, which helps to reduce the impact of process variations, minimizing readout errors, is proposed. [ABSTRACT FROM AUTHOR]

A top‐down transfer process is developed via a rolling process associated with thermal release tape/poly(methyl methacrylate) (PMMA) bi‐supporting layers to realize large‐scale transfer processes on transition metal dichalcogenide materials. A 2‐inch MoS2 thin film transferred on SiO2/Si substrates with high integrity and a yield of ≈99% can be successfully achieved via the proposed process. MoS2‐based transistors with a transferred Au thin film as the contact electrode indicate a lower contact resistance of 8.4 kΩ with improved mobility and a higher on/off ratio compared with that of the MoS2‐based transistors with the evaporated Au thin film as the contact electrode. By applying the difference in adhesion force between metal oxides and metal on MoS2 and PMMA surfaces, the selective transfer of MoS2 films can be demonstrated. Furthermore, all‐transferred MoS2‐based transistor arrays are demonstrated by combining the selectively transferred MoS2 film as the channel material and the transferred Au thin films as the contact electrode, which results in uniform electrical properties featuring a carrier mobility of 10.45 cm2 V−1 s−1, a subthreshold swing of 203.94 mV dec−1, a normalized Ion of 8.3 μA μm−1, and an on/off ratio of 105. [ABSTRACT FROM AUTHOR]

The electrochemical nitrogen reduction reaction (NRR) is an attractive process for next‐generation ammonia synthesis; therefore, identifying a suitable catalyst for this reaction is critical. In recent years, transition‐metal dichalcogenides (TMDs) and their Janus structures have gained significant attention because of their outstanding catalytic properties. However, the synthesis of Janus TMDs remains challenging, and exposing their active sites is difficult when using a low‐dimensional structure to improve the catalytic activity. To date, relatively little research has been conducted in this area. Herein, emerging Janus WSeS/WSe2 heterostructure nanowalls are systematically explored. These nanowalls are used as a nitrogen fixation catalyst in electrolytes. The nanowalls demonstrate a significant NH3 yield rate and Faradaic efficiency of 13.97 µg h‐mgcat−1 and 35.24% at −0.3 V in 0.1 m HCl, as well as 15.96 µg h‐mgcat−1 and 40.2% in 0.1 M Na2SO4. This study presents an in‐depth analysis of the properties of Janus WSeS/WSe2 heterostructure nanowalls and a conceptual framework for linking TMD‐based catalysts and the NRR. [ABSTRACT FROM AUTHOR]

The neuromorphic and in‐memory computing using memristors are promising for the building of the next generation computing systems. However, the diffusion dynamics of metal ions/atoms inside the switching medium impose variability in conducting filament (CF) formation, thus limiting their use in von‐Neumann architecture. The precise modulation on the diffusion of metal ions/atoms and their reduction/oxidation probability holds promise to overcome the speed, size, and energy issues of present‐day computers. Here, this study shows that the diffusion of metal ions can be modulated by defects inside the switching medium and confines metal filaments in a precise 1D channel. This filament confinement by the defect engineering leads to an anomalous switching mechanism with two interchangeable modes: unipolar threshold and bipolar modes. The variation between two modes can be modulated by controlling defects in the structures, leading to a uniform switching with low SET/RESET voltage variations of 17.3% and −17.6%, respectively. Moreover, the convolutional neural network is implemented to emulate synaptic plasticity and image recognition to achieve recognition accuracy of 87% due to a highly linear weight update, demonstrating its potential for in‐memory computing. [ABSTRACT FROM AUTHOR]

Here, nitrogen-doped molybdenum diselenide (MoSe2) films with nanoscaled thicknesses were fabricated by ionizing N2 carrier gas in a plasma-assisted chemical vapor reaction furnace under different mixtures of N2 and H2 ratios and the amount of nitrogen doping was controlled by the relative flow rate of N2. Nitrogen radicals diffused deeply in MoSe2 films once the reaction was activated in a N2-rich environment, resulting in a remarkable NH3 response of 430% at 25 ppm, 6.72 times the response against NO2. In contrast, nitrogen doping is limited at the surface under a H2-rich environment during the synthesis, resulting in a weaker response against NH3, which is only 37.5% of that against NO2 as prior researches. The enhanced NH3 response instead of NO2 in N-doped MoSe2 films with a bulk-like nitrogen doping can be attributed to the valence band being closer to the oxidation potential of NH3, which is favorable to donate electrons by NH3 molecules, along with a larger electron affinity than the reduction energy of NO2, hindering electron extraction toward gas molecules. The doping depths of both surface-limited doping and bulk-like doping can be precisely controlled at the nanoscale since the whole thickness of a MoSe2 film is close to 5 nm. The nanoscaled depths of nitrogen doping in MoSe2 films can easily determine the sensing target through atmospheric modification during the growth process, broadening the application potential of 2D-material-based gas sensors. [ABSTRACT FROM AUTHOR]

Pullulan based films possess several advantages, including high transparency, low toxicity, good biodegradability, good mechanical properties, and low oxygen permeability, are preferable for food packaging. The application of pullulan films on food packaging, however, has inherent disadvantage of high water solubility. In this study, glutaraldehyde and glycerol were used as the cross-linking reagent and the plasticizer respectively to improve water resistance and physical properties of the pullulan films. Effects of cross-linking degree on physical properties, including water absorptions, swelling behaviors, water vapor permeability and tensile strengths of films were evaluated. FTIR results demonstrated that the pullulan films were successfully cross-linked by glutaraldehyde. The tensile strength of pullulan films could be enhanced significantly ( P < 0.05) when glutaraldehyde was between 1% and 5% (w/w); nevertheless, the amount of glutaraldehyde above 20% (w/w) led to films brittleness. With the addition of glycerol as a plasticizer enhanced the extensibility of films as well as the hydrophilicity, resulting in higher water vapor permeability. [ABSTRACT FROM AUTHOR]

The nanoscale control of phase transition in correlated materials offers significant insight into phase transition dynamics for the advancement of future nanoelectronics devices. This study explores the phase transition phenomenon in vanadium dioxide (VO 2 ), focusing on the heterogeneous phases evolved after low-pressure plasma irradiation on VO 2 thin films, a strong electron-correlated material. The modulation in the Argon (Ar) plasma power reveals the formation of homogeneous and heterogeneous phases with variable resistive states at room temperature. High-resolution transmission electron microscopy (HRTEM) is observed with the change in interplanar spacing revealing monoclinic (M1) at 0W, monoclinic-tetragonal rutile (phase coexistence, M1-R) at 50W, and tetragonal rutile (R) at 90W. Dielectric force microscopy (DFM) shows distinct dielectric responses corresponding to different phases, characterized by potential differences of 3 mV (M1), 5 mV (M1-R), and 7.44 mV (R) phases. The coexistence of M1-R phase is stabilized and examined at room temperature, with variations in the charge carrier density observed relative to M1 and R phases individually. The phase change in VO 2 is found to be reversible, enabling stable resistive states even after the plasma is removed. The changes in plasma geometry help find and stabilize unstable phases, which can be useful in nanoelectronics., (© 2024 Wiley‐VCH GmbH.)

Efficient hydrogen generation from water splitting underpins chemistry to realize hydrogen economy. The electrocatalytic activity can be effectively modified by two-dimensional (2D) heterostructures, which offer great flexibility. Furthermore, they are useful in enhancing the exposure of the active sites for the hydrogen evolution reaction. Although the 1T-metallic phase of the transition metal dichalcogenides (TMDs) is important for the hydrogen evolution reaction (HER) catalyst, its practical application has not yet been much utilized because of the lack of stability of the 1T phase. Here, we introduce a novel approach to create a 1T-WS 2 /1T-WSe 2 heterostructure using a low-temperature plasma-assisted chemical vapor reaction (PACVR), namely plasma-assisted sulfurization and plasma-assisted selenization processes. This heterostructure exhibits superior electrocatalytic performance due to the presence of the metallic 1T phase and the beneficial synergistic effect at the interface, which is attributed to the transfer of electrons from the underlying WS 2 layer to the overlying WSe 2 layer. The WS 2 /WSe 2 heterostructure catalyst demonstrates remarkable performance in the HER as evidenced by its small Tafel slope of 57 mV dec -1 and exceptional durability. The usage of plasma helps in replacing the top S atoms with Se atoms, and this ion bombardment also increases the roughness of the thin film, thus adding another factor to enhance the HER performance. This plasma-synthesized low-temperature metallic-phase heterostructure brings out a novel method for the discovery of other catalysts.