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PtS2, a member of the group 10 transition metal dichalcogenides (TMDs), has received extensive attention because of its excellent electrical properties and air stability. However, there are few reports on the preparation of single-crystal PtS2 in the literature, and the growth mechanism of single crystal PtS2 is not well elucidated. In this work, we proposed a method of preparation that combines magnetron sputtering and chemical vapor transport to obtain monocrystalline PtS2 on a SiO2/Si substrate. By controlling the growth temperature and time, we have synthesized a single crystalline PtS2 of hexagonal shape and size of 1–2 μm on a silicon substrate. Combining the molecular dynamics simulation, the growth mechanism of single crystal PtS2 was investigated both experimentally and theoretically. The synthesis method has a short production cycle and low cost, which opens the door for the fabrication of other TMDs single crystals. [ABSTRACT FROM AUTHOR]

Skin‐like electronics research aiming to mimic even surpass human‐like specific tactile cognition by operating perception‐to‐cognition‐to‐feedback of stimulus to build intelligent cognition systems for certain imperceptible or inappreciable signals was so attractive. Herein, we constructed an all‐in‐one tri‐modal pressure sensing wearable device to address the issue of power supply by integrating multistage microstructured ionic skin (MM i‐skin) and thermoelectric self‐power staffs, which exhibits high sensitivity simultaneously. The MM i‐skin with multi‐stage "interlocked" configurations achieved precise recognition of subtle signals, where the sensitivity reached up to 3.95 kPa−1, as well as response time of 46 ms, cyclic stability (over 1500 cycles), a wide detection range of 0–200 kPa. Furthermore, we developed the thermoelectricity nanogenerator, piezoelectricity nanogenerator, and piezocapacitive sensing as an integrated tri‐modal pressure sensing, denoted as P‐iskin, T‐iskin, and C‐iskin, respectively. This multifunctional ionic skin enables real‐time monitoring of weak body signals, rehab guidance, and robotic motion recognition, demonstrating potential for Internet of things (IoT) applications involving the artificial intelligence‐motivated sapiential healthcare Internet (SHI) and widely distributed human‐machine interaction (HMI). [ABSTRACT FROM AUTHOR]

Wearable sweat biosensors, as the only noninvasive and measurable body-fluid sensors, serve as a very important means to monitor an individual's health status and more dynamic molecular-level information. The pursuit of wearable sweat biosensors includes not only detecting sweat components, but also integrating multiple functions, such as sweat-based health monitoring, near-field transmission and being self-powered. In this paper, we firstly bring forth a new idea of integrating sweat monitoring and dual electrical generation (hydrovoltaic and moisture electricity generation) for a multifunctional flexible device as a sweat-based health monitoring electronic (E)-skin. Herein, besides sweat composition analysis, a hydrovoltaic electricity generator is employed to detect the amount of sweat for the first time, and a dual electricity generator is used for self-supply of energy and skin-surface temperature measurement. Synergistic tandem nanogenerators are constructed using biomass carbon materials, and the power generation voltage can reach about 500 mV and is relatively stable. Our sweat E-skin (SE-skin) has five main functional areas, realizing real-time monitoring of sweat volume, sweat composition analysis skin-surface temperature measurement and power-supply functions. This new integrated design not only enables real-time monitoring of indicators of health in sweat, but also provides a new idea for future intelligent wearables for human beings. [ABSTRACT FROM AUTHOR]

Chemical vapor deposition (CVD)-grown 2D materials like MoS2 and WS2 have been widely used for research and application. Here, we study substrates' effects on CVD-grown MoS2 and WS2. The morphology, crystalline quality and optical properties have been modified while changing substrates, which can be derived from lattice matching between 2D materials and substrate, defect/impurities on the interface and conductance/transparency of different substrates. The results provide suggestion for further study in CVD growth of 2D materials and device fabrications. [ABSTRACT FROM AUTHOR]

Aunanocrystals coated with thiol derivatives of varying chain sizesranging from C12to C16were produced; two differentsize nanocrystals have been synthesized (5 and 7 nm in diameter) foreach coating agent. All of those specimens are characterized by alow size distribution (below 7%). Those Au nanocrystals were usedas building blocks to grow larger self-assembled crystalline structuresor supracrystals. These crystalline growths were carried out by slowand controlled solvent evaporation at different temperatures and undernon-null partial solvent vapor pressure (Pt). We show that the order within the supracrystals is temperature-dependentwhen they are made of hexadecanethiol-coated gold nanocrystals, regardlessof the size of the nanocrystals. The interparticle distances withinthe various supracrystals that were produced were determined by small-angleX-ray diffraction (SAXRD). We demonstrate that the interparticle distanceis controlled not only by the presence of physisorbed thiol residues,as previously reported, but also, at higher temperatures, by the dynamicsof the organic chains and the van der Waals forces involved betweenthe metallic cores of the nanocrystals forming the structure. [ABSTRACT FROM AUTHOR]

Au nanocrystals coated with thiolderivatives differing by thelength of their alkyl chains are used to build 3D superlattices calledsupracrystals. In this study, we used two sets of Au nanocrystalsdiffering by their sizes and size distributions. The average sizesare 5 nm (Au5) and 7 nm (Au7). From one experimentto the other, the size distribution slightly changes. For Au5nanocrystals, it evolves from 6 to 8%, and for Au7nanocrystals,it varies from 5 to 6%. The Au nanocrystals (Au5and Au7) are first dispersed in toluene and produce fcc supracrystalsby solvent evaporation. Here, by small-angle grazing X-ray diffraction,we observe a control in the average interparticle distance withinthe supracrystals. When the supracrystals are grown at zero toluenevapor pressure, the interparticle distances increase linearly withthe alkyl chain length of the nanocrystals’ coating agent regardlessof their diameters. Furthermore, the dry supracrystals can swell andthe interparticle distance within the superstructure be increasedby subjecting the material to toluene vapor pressure after initialgrowth. This swelling process is reversible, and retraction occurswhen the toluene vapor pressure drops. This indicates a strong abilityof the dried supracrystals to trap toluene molecules. On increasingthe toluene vapor pressure during the solvent evaporation process,the slope of the linear dependency of the interparticle distancesto the alkyl chain length is markedly decreased and the interparticledistance reaches a quasi-plateau. This is explained by the influenceof depletion forces created by the presence of thiol-containing moleculesphysisorbed on the coating molecules on the internal structure ofthese supracrystals. Recently, we demonstrated that, by using thesame nanocrystals (Au5and Au7), a hierarchyin the supracrystal growth process takes place from heterogeneousnucleation with the formation of a layer-by-layer film to homogeneousnucleation in solution with the formation of shaped supracrystals.Here it is shown that the interparticle distance is independent ofthe supracrystal growth mechanisms. [ABSTRACT FROM AUTHOR]

Herein, an integrated solar-thermal-power protocol is presented at a micro-nanoscopic level to maximize the energy utilization efficiency involving utilization period and utilization patterns, and the nexus of freshwater production and nanogeneration is realized. This sophisticated vaporization device is constructed with the merits of thermally confined evaporation space in favor of recycling latent heat of condensation and optimizing light absorption based on the local sunlight angle of incidence. Inspired by a bird's nest, Sb 2 WO 6 /D-Fructose composites are prepared as photothermal absorbers to achieve a superior water evaporation rate of 2.78 kg m -2  h -1 in the Multi-stage evaporator. In addition, a synergistic tandem photo thermal-electric device with a combination of solar-driven water evaporation and further waterflow-driven hydrovoltaic generation, which can output a stable voltage of up to 360.8 mV with effective utilization of steam energy and a limited water source, is exploited. Such integrated configurations pave a pathway for clean water production and renewable power generation simultaneously toward energy issues., (© 2024 Wiley-VCH GmbH.)

To develop next-generation electronic devices, novel semiconductive materials are urgently required. The transition metal dichalcogenides (TMDs) hold the promise of next generation of semiconductor materials for emerging electronic applications. As a member of the group-10 TMDs, PdS 2 has a notable layer-number-dependent band structure and tremendously high carrier mobility at room temperature. Here, we demonstrate the experimental realization of centimeter-scale synthesis of the few-layer PdS 2 by the combination of physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods. For the first time, the optical anisotropic properties of the few-layer PdS 2 were investigated through angle-resolved polarized Raman spectroscopy. Also, the evolution of Raman spectra was studied depending on the temperature in the range of 12-300 K. To further understand the electronic properties of the few-layer PdS 2 , the field-effect transistor (FET) devices were fabricated and investigated. The electronic measurements of such FET devices reveal that the PdS 2 materials exhibit a tunable ambipolar transport mechanism with field-effect mobility of up to ∼388 cm 2 V -1 s -1 and the on/off ratio of ∼800, which were not reported before in the literature. To well understand the experimental results, the electronic structure of PdS 2 was determined using density functional theory (DFT) calculations. These excellent physical properties are very helpful in developing high-performance opto-electronic applications.