Jiang-Tao Liu

This study presents a first-principles simulation-based optimization of contact resistance in MoS2field-effect transistors. In conventional top-contact designs, electron injection is limited to a smallregion near the channel, causing current crowding and high resistance. We systematically evaluatethree TiN/MoS2contact geometries—edge, C-type, and top—using density functional theory (DFT)combined with non-equilibrium Green’s function (NEGF) simulations. Our analysis reveals that thetop contact achieves the lowest resistance (63.7 Ω ∗ 𝜇𝑚), but only under heavy doping 1014cm2). Theedge contact suffers from a high Schottky barrier, resulting in large resistance, though heavy dopingpartially alleviates this. Remarkably, the C-type contact meets the International Roadmap for Devicesand Systems (IRDS) target simply by optimizing contact length—without requiring additional doping.These findings provide critical design guidelines for metal–2D semiconductor interfaces and supportthe integration of MoS2into future ultra-scaled electronics.

A theoretical study was conducted on a graphene ribbon suspended mass micro-electromechanical systems (MEMS) optical force (acceleration) sensor based on a Fabry–Perot (FP) microcavity. The study found that when the suspended mass is subjected to an external force or acceleration, its position shifts, altering the cavity length of the FP microcavity and thereby enabling optical sensing. The sensor can operate in both spectral and intensity modes. Benefiting from the ultrathin and highly stretchable properties of graphene, the sensor exhibits high sensitivity and a wide detection range. In spectral mode, the maximum sensitivity to force reaches −6nm/pN, and the sensitivity to acceleration can reach −1.4nm/g. In intensity mode, the force sensitivity can be as high as 0.74pN ⁻¹ . The designed sensor is ultra-compact, suitable for on-chip integration, and can be fabricated using large-scale manufacturing techniques. It holds significant potential for applications in wearable electronics, smart devices, robotics, and other fields.

Using the tight-binding method, we investigated the band structures, density of states, and optical absorption spectra of bilayer InSe quantum dots (QDs) with different stacking configurations. Further studies were conducted to examine the effects of external electric and magnetic fields on the band structures, as well as the electro- and magneto-optical absorption spectra. Our results reveal that the QD stacking structure significantly influences the bandgap, while the external fields modulates the anisotropy of the optical properties. This work provides valuable insights for experimental studies of InSe’s photoelectric properties and the development of anisotropic optical devices.