PtS2, a group-10 transition metal dichalcogenide, has prominent layer-depended band structure, and can enable extremely high phonon-limited mobility at room temperature. Here, we demonstrate the theoretical study on the electronic band structures of PtS2 with different thickness by using density functional theory (DFT), as well as experimental realization of large-area synthesis of few-layer PtS2 film by direct sulfurization of pre-deposited Pt. The synthetic process suggested that the reaction pressure is a key factor in the formation of high-quality PtS2 semiconducting films. Characterizations with atomic force microscopy (AFM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) have indicated that good film stoichiometry and uniformity have been achieved. Furthermore, field-effect transistor (FET) arrays were fabricated based on the large-scale PtS2 film, exhibiting well-uniform electrical performance with p-type transport behavior. These results can open up an attractive approach to promote the large-scale applications of PtS2 in advanced nanoelectronics and optoelectronics devices and systems.

No abstract

A generic loosely coupled effective stress method is presented in this article for one‐, two‐ and three‐ dimensional (1D, 2D and 3D) nonlinear site response analyses. In this method, the 1D non‐Masing hysteretic constitutive model of Chen et al (2020) is extended into 2D and 3D stress conditions, by presenting a clever generalized formulation of equivalent shear strain (γeq). The element‐level simulation tests show that the proposed algorithm of γeq is conceptually simple with high precision to capture the strain reversals under complex multidirectional shakings. The coupling between the cyclic stiffness degradation and the excess pore water pressure (EPWP) generation during irregular cyclic loadings is established using the proposed algorithm of γeq in conjunction with the Chen et al (2019a) EPWP generation model and the extended non‐Masing hysteretic constitutive model. The simulations of the undrained cyclic triaxial tests using the new effective stress method reproduce excellently the observed response of the saturated sand specimens, demonstrating the ability to represent the undrained behavior of liquefiable sands during uniform cyclic loadings. The new effective stress method is then used to simulate the response of a downhole array liquefied site in Japan, which shows an excellent agreement between the simulations and the recordings in both horizontal and vertical components of ground motions at different depths.

Substantial progress has been made in the experimental synthesis of large-area two-dimensional transition metal dichalcogenide (TMD) thin films in recent years. This has provided a solid basis to build non-planar structures to implement the unique electrical and mechanical properties of TMDs in various nanoelectronic and mechano-electric devices, which, however, has not yet been fully explored. In this work, we demonstrate the fabrication and characterization of MoS2 field-effect transistors (FETs) with an omega (Ω)-shaped gate. The FET is built based on the SiO2/MoS2 core–shell heterostructure integrated using atomic layer deposition (ALD) technique. The MoS2 thin film has been uniformly deposited by ALD as wrapping the SiO2 nanowire forming the channel region, which is further surrounded by the gate dielectric and the Ω-gate. The device has exhibited n-type behavior with effective switching comparable to the reference device with a planar MoS2 channel built on a SiO2/Si substrate. Our work opens up an attractive avenue to realize novel device structures utilizing synthetic TMDs, thereby broadening their potential application in future advanced nanoelectronics.