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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]

Herein, oxygen‐incorporated 2D‐SnSe2 layered films are successfully fabricated by a plasma‐assisted selenization process. The oxygen concentrations inside the 2D‐SnSe2 layered film are controllable by controlling the proportion of hydrogen in the mixed gas of nitrogen and hydrogen during the plasma‐assisted selenization reaction. Oxygen atoms mainly exist in the form of the incorporated oxygen in the 2D‐SnSe2 layered film with an exceedingly small grain size of SnO2, which significantly increases the total interface area of the SnO2/SnSe2. Significant enhancement of the gas response to NO2 (709% under 100 ppb NO2) is reached when the proportion of hydrogen during the plasma‐assisted selenization process is 25%, thus showing excellent sensitivity and selectivity. Moreover, the sensor also demonstrated excellent stability under an increase in relative humidity. It is verified that the response will not significantly decrease when the relative humidity is below 90%. The obtained results demonstrate that oxygen‐incorporated 2D‐SnSe2 layered film with excellent commercial potential, is a highly suitable candidate for next‐generation gas sensors. [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]

Electronics is advancing toward greater diversity and sustainability by prioritizing energy efficiency and cost-effectiveness. Metal oxide thin-film transistor (TFT) represents a technology at the forefront of advancing next-generation sustainable electronics, and exploring oxide channel compositions is a crucial step in opening opportunities for developing next-generation device applications. This study presents the first development of n-channel α-Bi 2 O 3 -TFTs using a 4 nm ultrathin channel prepared by a cost-effective vacuum-free and solvent-free liquid metal printing method in ambient air. Even the pristine device exhibited a clear TFT action but required a large negative gate bias to turn off due mainly to excess carriers from oxygen vacancy in the α-Bi 2 O 3 channel. Oxygen-containing post-annealing reduced both channel carrier and subgap defect densities, enabling the development of depletion and enhancement-type α-Bi 2 O 3 -TFTs with the saturation mobility of 2-4 cm 2 V -1 s -1 . Two types of oxide-TFT-based inverter circuits, zero-V GS -NMOS and CMOS inverters, were fabricated by using α-Bi 2 O 3 -TFTs, operating in a high voltage gain of over 130. This work demonstrates the potential of oxide semiconductor materials toward the development of next-generation sustainable electronics.

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.

Herein, the structure of integrated M3D inverters are successfully demonstrated where a chemical vapor deposition (CVD) synthesized monolayer WSe 2 p-type nanosheet FET is vertically integrated on top of CVD synthesized monolayer MoS 2 n-type film FET arrays (2.5 × 2.5 cm) by semiconductor industry techniques, such as transfer, e-beam evaporation (EBV), and plasma etching processes. A low temperature (below 250 °C) is employed to protect the WSe 2 and MoS 2 channel materials from thermal decomposition during the whole fabrication process. The MoS 2 NMOS and WSe 2 PMOS device fabricated show an on/off current ratio exceeding 10 6 and the integrated M3D inverters indicate an average voltage gain of ≈9 at V DD = 2 V. In addition, the integrated M3D inverter demonstrates an ultra-low power consumption of 0.112 nW at a V DD of 1 V. Statistical analysis of the fabricated inverters devices shows their high reliability, rendering them suitable for large-area applications. The successful demonstration of M3D inverters based on large-scale 2D monolayer TMDs indicate their high potential for advancing the application of 2D TMDs in future integrated circuits., (© 2024 Wiley‐VCH GmbH.)