First-principles studies on the electronic and contact properties of monolayer Ga2STe-metal contacts.

Monolayer (ML) Janus III-VI compounds have attracted the use of multiple competitive platforms for future-generation functional electronics, including non-volatile memories, field effect transistors, and sensors. In this work, the electronic and interfacial properties of ML Ga2STe-metal (Au, Ag, Cu, and Al) contacts are systematically investigated using first-principles calculations combined with the non-equilibrium Green's function method. The ML Ga2STe-Au/Ag/Al contacts exhibit weak electronic orbital hybridization at the interface, while the ML Ga2STe-Cu contact exhibits strong electronic orbital hybridization. The Te surface is more conducive to electron injection than the S surface in ML Ga2STe-metal contact. Quantum transport calculations revealed that when the Te side of the ML Ga2STe is in contact with Au, Ag and Cu electrodes, p-type Schottky contacts are formed. When in contact with the Al electrode, an n-type Schottky contact is formed with an electron SBH of 0.079 eV. When the S side of ML Ga2STe is in contact with Au and Al electrodes, p-type Schottky contacts are formed, and when it is in contact with Ag and Cu electrodes, n-type Schottky contacts are formed. Our study will guide the selection of appropriate metal electrodes for constructing ML Ga2STe devices.

Interfacial electronic states and self-formed asymmetric Schottky contacts in polar α-In2Se3/Au contacts.

In recent years, the two-dimensional (2D) semiconductor α-In2Se3 has great potential for applications in the fields of electronics and optoelectronics due to its spontaneous iron electrolysis properties. Through ab initio electronic structure calculations and quantum transport simulations, the interface properties and transport properties of α-In2Se3/Au contacts with different polarization directions are studied, and a two-dimensional α-In2Se3 asymmetric metal contact design is proposed. When α-In2Se3 is polarized upward, it forms an n-type Schottky contact with Au. While when α-In2Se3 is polarized downward, it forms a p-type Schottky contact with Au. More importantly, significant rectification effect is found in the asymmetric Au/α-In2Se3/Au field-effect transistor. The carrier transports under positive and negative bias voltages are found to be dominated by thermionic excitation and tunneling, respectively. These findings provide guidance for the further design of 2D α-In2Se3-based transistors.

Weld Seam Tracking and Detection Robot Based on Artificial Intelligence Technology.

The regular detection of weld seams in large-scale special equipment is crucial for improving safety and efficiency, and this can be achieved effectively through the use of weld seam tracking and detection robots. In this study, a wall-climbing robot with integrated seam tracking and detection was designed, and the wall climbing function was realized via a permanent magnet array and a Mecanum wheel. The function of weld seam tracking and detection was realized using a DeepLabv3+ semantic segmentation model. Several optimizations were implemented to enhance the deployment of the DeepLabv3+ semantic segmentation model on embedded devices. Mobilenetv2 was used to replace the feature extraction network of the original model, and the convolutional block attention module attention mechanism was introduced into the encoder module. All traditional 3×3 convolutions were substituted with depthwise separable dilated convolutions. Subsequently, the welding path was fitted using the least squares method based on the segmentation results. The experimental results showed that the volume of the improved model was reduced by 92.9%, only being 21.8 Mb. The average precision reached 98.5%, surpassing the original model by 1.4%. The reasoning speed was accelerated to 21 frames/s, satisfying the real-time requirements of industrial detection. The detection robot successfully realizes the autonomous identification and tracking of weld seams. This study remarkably contributes to the development of automatic and intelligent weld seam detection technologies.

First-principles study on electronic states of In2Se3/Au heterostructure controlled by strain engineering.

The development of low-dimensional multifunctional devices has become increasingly important as the size of field-effect transistors decreases. In recent years, the two-dimensional (2D) semiconductor In2Se3 has emerged as a promising candidate for applications in the fields of electronics and optoelectronics owing to its remarkable spontaneous polarization properties. Through first-principles calculations, the effects of the polarization direction and biaxial tensile strain on the electronic and contact properties of In2Se3/Au heterostructures are investigated. The contact type of In2Se3/Au heterostructures depends on the polarization direction of In2Se3. The more charge transfers from the metal to the space charge region, the biaxial tensile strain increases. Moreover, the upward polarized In2Se3 in contact with Au maintains a constant n-type Schottky contact as the biaxial tensile strain increases, with a barrier height Φ SB,n of only 0.086 eV at 6% strain, which is close to ohmic contact. On the other hand, the downward polarized In2Se3 in contact with Au can be transformed from p-type to n-type by applying a biaxial tensile strain. Our calculation results can provide a reference for the design and fabrication of In2Se3-based field effect transistors.