A synergetic promotion of surface stability for high-voltage LiCoO by multi-element surface doping: a first-principles study.

The utilization of high-voltage LiCoO is an effective approach to break through the bottleneck of practical energy density in lithium ion batteries. However, the structural and interfacial degradations at the deeply delithiated state as well as the associated safety concerns impede the application of high-voltage LiCoO. Herein, we present a synergetic strategy for promoting the surface stability of LiCoO at high voltage by Ti-Mg-Al co-doping and systematically study the effects of the dopants on the surface stability, electronic structure and Li diffusion properties of the LiCoO (104) surface using first-principles calculations.

The interfacial properties of 2D metal-monolayer blue phosphorene heterojunctions and transport properties of their field-effect transistors.

Monolayer blue phosphorene (BlueP) has attracted much interest as a potential channel material in electronic devices. Searching for suitable two-dimensional (2D) metal materials to use as electrodes is critical to fabricating high-performance nanoscale channel BlueP-based field effect transistors (FETs). In this paper, we adopted first-principles calculations to explore binding energies, phonon calculations and electronic structures of 2D metal-BlueP heterojunctions, including TiC-, NbTe-, Ga(110)- and NbS-BlueP, and thermal stability of TiC-BlueP heterojunction at room temperature.

A first-principles study of bilayered black phosphorene as a potential anode material for sodium-ion batteries.

Black phosphorene has attracted widespread attention because of its great potential as a high-performance anode material for sodium-ion batteries (SIBs). However, almost all theoretical studies on sodium (Na) atom adsorption and diffusion in it have not taken temperature into account. Actually, the structural stability of an anode material at room temperature is vital in practical applications.

Effect of non-magnetic doping on magnetic state and Li/Na adsorption and diffusion of black phosphorene.

Black phosphorene (BP) have aroused great concern because of its great potential for the application in nanoelectronic devices and high-performance anode materials for alkali metal ion batteries (AIBs). However, the absence of magnetism for an ideal BP limits its wide application in spintronic devices which is one of the important nanoelectronic devices, and its application as a high-performance anode material for AIBs is still to be explored. In this paper, we adopt first-principles calculations to explore the effects of B, C, N, O, F, Al, Si and S atom doping on the magnetic state of monolayer BP and Li or Na atom adsorption and diffusion on the BP.

One- and two-dimensional electrical contacts and transport properties in monolayer black phosphorene-Ni interface.

Contacts between black phosphorene (BP) and metal electrodes are critical components of BP-based devices and can dramatically affect device performance. In this paper, we adopted first-principles calculations to explore binding energies, electronic structures, spatial potential distribution of monolayer BP-Ni interfaces in surface contact and edge contact types, and used density functional theoretical coupled with nonequilibrium Green's function method to investigate the electrical transport properties for transport systems of monolayer BP with Ni electrodes. Our calculated results indicate that contact type between monolayer BP and metal Ni electrodes may much affect the transport properties of monolayer BP-Ni devices.

Robustness of the electronic structure and charge transfer in topological insulator BiTeSe and BiSeTe thin films under an external electric field.

Using first-principles calculations based on density functional theory, we systematically investigated the electronic properties and charge transfer of topological insulator BiTeSe thin films under an external electric field. As the selenium content in BiTeSe thin films increases, the band gap is gradually opened, with changes in the charge distribution. In addition, the experimentally stable BiTeSe and BiSeTe thin films are extremely robust under vertical electric fields up to 0.

Strain-engineered indirect-direct band-gap transitions of PbPdO slab with preferred (0 0 2) orientation.

Layered transition metal oxide PbPdO has great potential application in electronic devices because of its unique electronic structure and large thermoelectric power at room temperature. In this work, strain effect on the electronic structure of PbPdO slab with preferred (0 0 2) orientation was systematically investigated using first-principles calculation. The calculated results indicate that PbPdO ultrathin slab possesses a small indirect gap while an indirect-direct band gap transition occurs when a moderate 2% compression or tensile strain is applied on the slab.

Band-structure engineering of the magnetically Cr-doped topological insulator SbTe under mechanical strain.

Magnetic doping in topological insulator SbTe can produce very novel physical phenomena such as quantum anomalous Hall effect (QAHE). However, experimental observations of QAHE in the magnetic atoms doped SbTe have encountered significant challenges due to the complexity of the electronic structure and the relatively small band gap. Generally, mechanical strain can effectively modulate the band structure, thus we theoretically investigate the electronic structures of Cr-doped SbTe under mechanical strain using first-principles calculations within density functional theory.

Strain Engineered Band Gaps and Electronic Properties in PbPdO₂ and PbPdCoO₂ Slabs.

Electronic structure and corresponding electrical properties of PbPdO₂ and PbPdCoO₂ ultrathin slabs with (002) preferred orientation were systematically investigated using first-principles calculations. The calculated results revealed the strain induced evidently the changes of band structure and carrier concentration in both slabs. It was also found that PbPdO₂ and PbPdCoO₂ ultrathin slabs exhibited evident differences in the external strain dependence of the band gap and charge carrier concentration, which was strongly dependent on bond angle and bond length induced by in-plane anisotropy strain.

The Phase Evolution and Physical Properties of Binary Copper Oxide Thin Films Prepared by Reactive Magnetron Sputtering.

P-type binary copper oxide semiconductor films for various O₂ flow rates and total pressures () were prepared using the reactive magnetron sputtering method. Their morphologies and structures were detected by X-ray diffraction, Raman spectrometry, and SEM. A phase diagram with Cu₂O, Cu₄O₃, CuO, and their mixture was established.

Effects of graphene intercalation on dielectric reliability of HfO and modulation of effective work function for Ni/Gr/c-HfO interfaces: first-principles study.

We have investigated the effects of graphene intercalation on dielectric reliability of HfO for Ni/Gr/HfO interfaces, and the effects of graphene intercalation and interfacial atom vacancy on the effective work function (EWF) of Ni/Gr/HfO interfaces using first-principle calculation based on density functional theory. The calculated results indicate that graphene intercalation can improve dielectric reliability of HfO dielectric even for the interfaces having interfacial oxygen vacancy or a small amount carbon vacancy. Moreover, the calculated results indicate that, inserting graphene into Ni/HfO interface induces the EWF's to decline, and controlling interfacial oxygen or carbon vacancy can effectively tune the EWF of Ni/Gr/HfO interface.

An Ab Initio and Kinetic Monte Carlo Simulation Study of Lithium Ion Diffusion on Graphene.

The Li⁺ diffusion coefficients in Li⁺-adsorbed graphene systems were determined by combining first-principle calculations based on density functional theory with Kinetic Monte Carlo simulations. The calculated results indicate that the interactions between Li ions have a very important influence on lithium diffusion. Based on energy barriers directly obtained from first-principle calculations for single-Li⁺ and two-Li⁺ adsorbed systems, a new equation predicting energy barriers with more than two Li ions was deduced.

Electronic structure and its external electric field modulation of PbPdO ultrathin slabs with (002) and (211) preferred orientations.

The Electronic structure of PbPdO with (002) and (211) preferred orientations were investigated using first-principles calculation. The calculated results indicate that, (002) and (211) orientations exhibit different electric field dependence of band-gap and carrier concentration. The small band gap and more sensitive electric field modulation of band gap were found in (002) orientation.