Atomically thin two-dimensional (2D) materials make it possible to create a variety of van der Waals (vdW) heterostructures with different physical features and attributes, which enables the growth of innovative electronics and optoelectronics applications. The band alignment and charge transfer play a crucial role in the physical and optoelectrical properties of the vdW heterostructure. Here, we design a vdW heterojunction device comprising low-symmetric CrOCl to induce a stable anti-ambipolar behavior and polarization-sensitive photodetection performance. 2D CrOCl exhibits strong in-plane anisotropy and linear dichroism, and an anti-ambipolar transport behavior is observed in a MoTe2 channel due to the gate-tunable band bending and charge transfer at MoTe2/CrOCl interface. The devices also exhibit well photodetection performance with a responsivity of 1.05 A/W and a temporal response of 970 μs. Owing to the anisotropic CrOCl serving as a photosensitizing layer, the device achieves the capability of polarization-sensitive photodetection with a photocurrent dichroic ratio up to ∼6. This work offers a valid device model and design strategy to realize the versatile optoelectronics, including the anti-ambipolar transistor and polarimetric photodetectors.

The hydrogen spillover strategy was demonstrated to enhance the HER activity of Ru in alkaline electrolytes through Co doping into NiSe. 1.5 wt% Ru–Ni0.85Co0.15Se/NF with a smaller |ΔΦ| value showed a superior HER performance and stability.

The frictional properties of a uniaxial tensile strained graphene interface are studied using molecular dynamics simulations. A misfit interval statistical method (MISM) is applied to characterize the atomistic misfits at the interface and strain soliton pattern. During sliding along both armchair and zigzag directions, the lateral force depends on the ratio of graphene flake length (L) to strain soliton spacing (L s ) and becomes nearly zero when L is an integer multiple of 3L s . Furthermore, the strain solitons propagate along the armchair sliding direction dynamically, while fission and fusion are repeatedly evidenced along the zigzag sliding direction. The underlying superlubric mechanism is revealed by a single-atom quasi-static model. The cancellation of lateral force for the contacting atoms exhibits a dynamic balance when sliding along the armchair direction but a quasi-static balance along the zigzag direction. A diagram of flake length with respect to tensile strain (L−ε) is proposed to predict the critical condition for the transition from nonsuperlubricity to superlubricity. Our results provide insights on the design of superlubric devices.

Field-effect transistors (FETs) fabricated with monolayer (ML) molybdenum disulfide (MoS 2 ) exhibit great potential as a promising candidate for next-generation nanoelectronic devices. However, the practical application of ML-MoS 2 -based transistors is severely restricted by the high contact resistance and poor current-delivery capability between the common metals and ML-MoS 2 at present. Here, through the systematical screening of the contact performance between metals (Sc, In

Fe 3 GeTe 2 (FGT) is one of the most attractive two-dimensional (2D) magnetic metals owing to the long-range ferromagnetic order and high Curie temperature. The electronic transition is of great importance for understanding the magnetic physics and spintronic applications in FGT. Although the ferromagnetic properties of FGT are well known, the band structure and electronic transition in both theory and experiment have been rarely studied. Here, we use density functional theory (DFT) and the magnetic circular dichroism (MCD) technique to study the electronic transition and phase transition of magnetic FGT. The electronic transitions at energy of 1.6 and 2.2 eV were observed through the reflection spectrum, which are further evidenced by first-principles calculations. At the critical temperature (170 K) where the ferromagnetic to paramagnetic phase transition happens, the interband electronic transition at 2.2 eV vanishes due to the disappearance of flat bands between the Γ-M point. Besides, a step appears in the hysteresis loop at the magnetic field of ±0.07 T where both the MCD and reflection spectrum also undergo an obvious change. This work has correlated the phase transition with electronic transition, offering a new degree of freedom to study the magnetic physics of ferromagnetic metals.