Hong Li

A sub-5 nm ML SnS ₂ DSFET outperforms its MOSFET counterpart and previously reported graphene-source DSFETs in low-power metrics. This superior performance stems from the n-type ohmic contact with efficient electron tunneling probability.

We identify 33 stable metallic MXenes from 256 candidates; three n- and three p-type MXenes are screened for ML GeC. Optimal n- and p-type electrodes are Nb ₂ C(OH) ₂ and Ti ₂ CS ₂ , delivering symmetric performance exceeding IRDS LP and HP goals.

Two-dimensional tungsten diselenide (2D WSe ₂ ) has emerged as a leading candidate for post-silicon nanoelectronics. A critical determinant of high-performance WSe ₂ -based devices is the realization of ideal electrodes that form low-resistivity Ohmic contacts. To address this challenge, we conduct a comprehensive first-principles study to evaluate the interfacial characteristics between bilayer (BL) WSe ₂ and various monolayer (ML) metallic candidates. By applying work function alignment and lattice compatibility as initial screening criteria, six promising electrode materials — Zr ₂ NF ₂ , Sc ₂ NF ₂ , Hf ₂ NF ₂ , Sc ₂ NO ₂ , 2H-TaSe ₂ , and 2H-NbSe ₂ — are identified. Among these, Zr ₂ NF ₂ , Sc ₂ NF ₂ , and Hf ₂ NF ₂ form n-type Ohmic contacts with BL WSe ₂ , with the Hf ₂ NF ₂ /BL WSe ₂ interface exhibiting optimal performance with moderate lattice mismatch of 4.18%, a stable negative binding energy of [ ]22.79 meV/Å ² , the highest electron tunneling probability of 29.91%, and the lowest tunneling-specific resistivity of [ ]cm ² . ML Sc ₂ NO ₂ , 2H-TaSe ₂ , and 2H-NbSe ₂ form p-type Ohmic contacts, among which the 2H-TaSe ₂ /BL WSe ₂ interface demonstrates the most favorable overall characteristics, including an exceptionally low lattice mismatch of [ ]0.94%, a stable binding energy of [ ]53.72[ ]meV/Å ² , and balanced transport properties with moderate tunneling probability (12.57%) and tunneling-specific resistivity ([ ]cm ² ). This systematic investigation provides essential theoretical guidance for the rational design of high-performance nanoelectronic devices incorporating low-resistance Ohmic interfaces.

Van der Waals (vdW) heterostructures have atomically smooth interfaces, providing an innovative path for the development of the next generation of electronic devices. Among them, the interface contact characteristics are the core of the performance research of these heterostructures. In this study, the regulatory effect of an external electric field on the electronic properties and tribological behavior of graphene/GeSe vdW heterostructures was systematically explored by first-principles calculations. The research results reveal that modulating the direction and intensity of the external electric field can effectively control the interlayer distance and electronic properties of heterostructures. The application of a positive electric field induces a compressive deformation within the graphene interlayers. Conversely, a negative electric field generates an interlayer electrostatic repulsion, leading to a pronounced expansion of the interlayer distance. When the intensity of the electric field exceeds -0.15 V/Å, it is observed that the interface contact of the heterostructure changes from an ohmic contact to n-type Schottky contact. The polarization and accumulation of interlayer charges in heterostructures under the action of an electric field also have a significant impact on the coefficient of friction. These findings provide significant guidance for advanced micro-nano manufacturing technologies that require precise control of electronic and tribological properties.

2D MoS ₂ MOSFETs show layer-dependent performance. A 10-nm-gate ML device with optimal doping delivers the best p-type performance for both LP and HP applications, whereas the optimal BL devices achieve nearly balanced n- and p-type performance.

This study focuses on porous polyimide (PPI) lubricating materials for high-speed aerospace bearings. Based on their real microstructure, three-dimensional digital model reconstruction and mesoscale seepage characteristics were investigated. First, a sequence of two-dimensional slice images of PPI was obtained using micro-focus X-ray computed tomography (CT). Through image filtering, threshold segmentation, and three-dimensional reconstruction, a highly faithful digital model of the pore structure was constructed, and a quantified pore-network model was further extracted. Second, a multiple-relaxation-time lattice Boltzmann model based on the D3Q27 discrete scheme was established, and its accuracy and stability in complex boundaries and pressure-driven flows were verified using classic benchmark cases. Subsequently, the validated numerical model was applied to the reconstructed PPI pore structure to simulate and systematically analyze the single-phase seepage behavior of lubricating oil. The results show that the lubricant seepage exhibits a strong “preferential flow path” effect, with most of the flow transported through a small number of large-size throats. A clear quantitative relationship exists between the microscopic flow field structure—including velocity distribution, flow paths, and pressure gradient—and the pore-topology features, such as throat-size distribution, connectivity, and tortuosity. This verifies the mesoscale mechanism that “structure governs flow.” The complete technical chain established in this work—“real-structure reconstruction–numerical model validation–seepage mechanism analysis”—provides a reliable theoretical and numerical tool for gaining deeper insight into the lubricant transport behavior in porous polyimide and offers guidance for the microstructural design and optimization of this material.

Symmetric n- and p-type 2D SBFETs are realized using BL MoS ₂ in conjunction with ML Sc ₂ NF ₂ and Sc ₂ NO ₂ electrodes, respectively, demonstrating device performances that exceed the IRDS targets for HP applications in the ‘5am eq’ roadmap.