By using density functional theory and ab initio quantum-transport simulation, we study the Schottky barrier and the rectifying behavior of diodes consisting of the two-dimensional metal phase $1T\text{−}{\mathrm{MoS}}_2$ and semiconductor phase 2H-${\mathrm{MoS}}_2$. The results show that the Schottky barrier of the out-of-plane (OP) contacted ${\mathrm{MoS}}_2$ heterostructure diode is a little different from that of the in-plane (IP) contacted ${\mathrm{MoS}}_2$ heterostructure diode. The current-voltage characteristics show that the OP diode has the better rectifying behavior compared to the IP diode under the zero gate voltage. The corresponding maximum rectifier ratio of the OP Schottky barrier diode is close to ${10}^7$ at 0.9 V bias voltage. More interestingly, we find that the gate voltage can be used to effectively control the rectifying behavior of the two diodes. The positive gate voltages can increase the current value of two Schottky barrier diodes, but weaken their rectification ratios. The negative gate voltages can reverse the rectifying direction of two Schottky barrier diodes. The above results provide good theoretical guidance for the designing of diode devices based on two-dimensional materials in the future.

Transfer characteristics and benchmarks of 5.1 nm double-gated SBFETs consisting of IP heterojunctions of the metallic-phase MTe₂ (M = Ti, Zr, Hf, Cr, Mo, W) and semiconducting-phase WSe₂, WTe₂ and Janus WSeTe are studied in this paper.

Nickel-rich layered LiNi_1−x−yCo_xMn_yO₂ (LiMO₂) is widely investigated as a promising cathode material for advanced lithium-ion batteries used in electric vehicles, and a much higher energy density in higher cut-off voltage is emergent for long driving range. However, during extensive cycling when charged to higher voltage, the battery exhibits severe capacity fading and obvious structural collapse, which leads to poor cycle stability. Herein, Sn-doping and in situ formed Li₂SnO₃ nano-coating layer co-modified spherical-like LiNi_0.5Co_0.2Mn_0.3O₂ samples were successfully prepared using a facile molten salt method and demonstrated excellent cyclic properties and high-rate capabilities. The transition metal site was expected to be substituted by Sn in this study. The original crystal structures of the layered materials were influenced by Sn-doping. Sn not only entered into the crystal lattice of LiNi_0.5Co_0.2Mn_0.3O₂, but also formed Li⁺-conductive Li₂SnO₃ on the surface. Sn-doping and Li₂SnO₃ coating layer co-modification are helpful to optimize the ratio of Ni²⁺ and Ni³⁺, and to improve the conductivity of the cathode. The reversible capacity and rate capability of the cathode are improved by Sn-modification. The 3 mol% Sn-modified LiNi_0.5Co_0.2Mn_0.3O₂ sample maintained the reversible capacity of 146.8 mAh g⁻¹ at 5C, corresponding to 75.8% of its low-rate capacity (0.1C, 193.7mAh g⁻¹) and kept the reversible capacity of 157.3 mAh g⁻¹ with 88.4% capacity retention after 100 charge and discharge cycles at 1C rate between 2.7 and 4.6 V, showing the improved electrochemical property.

Enhancing the band-to-band tunneling (BTBT) is the most effective method to improve the performance of the tunnel field effect transistors (TFETs). In this article, the transport properties of monolayer blue phosphorene (BP) and transition metals Ag or Mn decorated BP 5-nm TFETs along the armchair edge (AE) or zigzag edge (ZE) transport directions were studied by using density functional theory and non-equilibrium Green’s function formalism. The transfer charges between metal atoms and BP will induce the new energy bands to modulate the band structure of BP effectively. The ON-state currents of monolayer BP TFET are just 113 and $77~\mu \text{A}/\mu \text{m}$ along the AE or ZE transport directions. The adsorption Mn atom can induce band gap states, and ON-state currents of Mn-decorated TFET along the AE or ZE transport directions can be improved to 616 and $646~\mu \text{A}/\mu \text{m}$ , respectively. Although the band gap states induced by adsorbed Ag atom are less than those induced by adsorbed Mn atom, ON-state currents of Ag-decorated TFET along the AE or ZE transport directions could reach to 972 and $1308~\mu \text{A}/\mu \text{m}$ , which both meet the requirement of high performance (HP) logic applications for the next decade in the International Technology Roadmap for Semiconductors (ITRS). In addition, ON-state currents of Ag-decorated TFET including phonon-assisted tunneling along the AE and the ZE transport directions further increase to 1003 and $1823~\mu \text{A}/\mu \text{m}$ , and better meet the HP requirements in ITRS.