Papers by Keyword: Binding Energy

Abstract: The study involves treating various metal complexes in "gas phase" with the prepared ligands (2,6-bis (((1-octyl-1H-1,2,3-triazol-4-yl) methoxy) methyl) pyridine (L₁), 2,6-bis (((1-decyl-1H-1,2,3-triazol-4-yl) methoxy) methyl) pyridine (L₂) and 2,6-bis (((1-dodecyl-1H-1,2,3-triazol-4-yl) methoxy) methyl) pyridine (L₃). Two different types of programs, the Hyperchem-8 and Gaussian programs, were used to study the theory. The heat of formation (ΔH^of), binding energy (ΔEb), and dipole moment (µ) for free ligands and some metal complexes were calculated using semi-experimental and molecular mechanics in the Hyper-8 program using a variety of computational techniques including ZINDO/1, PM3, and AMBER methods at room temperature. The created complexes are discovered to be more stable than the free ligands. For proper location of the molecules, Hyperchem.-8 was used to determine the vibration frequencies for (FT-IR) and electronic transitions, as well as electrostatic potential, HOMO, and LUMO energy. The compatibility of the theoretical and experimental findings was highlighted. In order to calculate the geometry optimization, dipole moment (µ), total energy, electrostatic potential, LUMO, and HOMO, a Gaussian algorithm employing a semi-empirical (PM3) approach was utilized. "Vibration spectra of free ligands are calculated and noted that they agreed well with those values experimentally found" diagnosis with a higher level of capacity to effectively diagnose packages. Using a technique like ZINDO/S, the electronic transitions for the ligand were also computed.

Abstract: In this work, we have studied an electron confined in a GaAs Horn torus quantum dot in the presence of a shallow donor impurity. Using the effective mass approximation and by considering an infinite confinement potential, the Schrödinger equation was calculated by the finite difference method. The electron-impurity binding energy and the diamagnetic susceptibility are studied for different geometric sizes of the Horn torus. In addition, the effect of the radial and angular positions of the shallow donor impurity on the binding energy and the diamagnetic susceptibility are examined. The results show that the binding energy is much higher at small sizes of the nano system. Also, the diamagnetic susceptibility exhibits a symmetric behavior as a function of the angular position of the shallow impurity donor unlike that when the impurity moves radially. The influences of these parameter variants help us to better understand the effects of the size of the quantum dot and the position of the donor impurity, which improve the sensitive of the opto-electronic devices.

Abstract: Recently, two-dimensional (2D) materials have been rapidly developed and they provided a wide application on the anode of the batteries, reducing the adverse effect of traditional ion batteries including low capacity, short cycle life, low charging rate and poor safety mainly coming from the use of graphite anode. The current report investigates the anode performances of AlSi, a new 2D material exfoliated from NaAlSi, for Li ion batterys (LIBs) through density functional theory (DFT) calculations and gives quantitative discussions on the Li ion valences, binding energies and open-circuit voltages of 2D AlSi anode. The results indicate that 2D AlSi performs great as a novel anode due to the moderate adhesion to Li and low barrier for ion diffusion. Furthermore, our research results illustrate a broad application prospect on the new anode inventions as well as reducing useless consumption on the batteries by the practice of AlSi anode.

Abstract: The development of next generation Li ion battery has attracted many attentions of researchers due to the rapidly increasing demands to portable energy storage devices. General Li metal/alloy anodes are confronted with challenges of dendritic crystal formation and slow charge/discharge rate. Recently, the prosperity of two-dimensional materials opens a new window for the design of battery anode. In the present study, MoS₂/graphene heterostructure is investigate for the anode application of Li ion battery using first-principles calculations. The Li binding energy, open-circuit voltage, and electronic band structures are acquired for various Li concentrations. We found the open-circuit voltage decreases from ~2.28 to ~0.4 V for concentration from 0 to 1. Density of states show the electrical conductivity of the intercalated heterostructures can be significantly enhanced. The charge density differences are used to explain the variations of voltage and density of states. Last, ~0.43 eV diffusion energy barrier of Li implies the possible fast charge/discharge rate. Our study indicate MoS₂/graphene heterostructure is promising material as Li ion battery anode.

Abstract: Recently, two-dimensional (2D) material developed rapidly and provided a wide application on the anode of the batteries, reducing the adverse effect of traditional ion batteries such as low capacity, short cycle life, slow charging and poor safety mainly coming from the use of graphite anode. The current report investigates the anode performances of phosphorus, a new 2D material in electrochemistry field, with monolayer and bilayer structure for Li ion batterys (LIBs) through density functional theory (DFT) calculations and gives a comparison on the Li ion valences, binding energies and open-circuit voltages between the two structures. The results indicate that bilayer phosphorus perform better as a novel anode due to the stronger adhesion to Li and lower barrier for ion diffusion. Furthermore, our research results illustrate a broad application prospect on the new anode inventions as well as reducing useless consumption on the batteries by the practice of bilayer phosphorus anode.

Abstract: Due to the development of various mobile electronic devices, such as electric vehicles, rechargeable ion batteries are becoming more and more important. However, the current commercial lithium-ion batteries have obvious defects, including poor safety from Li dendrite and flammable electrolyte, quick capacity loss and low charging and discharging rate. It is very important to find a better two-dimensional material as the anode of the battery to recover the disadvantages. In this paper, first principles calculations are used to explore the performances of VS₂ bilayer and VS₂ / graphene heterostructure as the anodes of Li ion batteries. Based on the calculation of the valences, binding energy, intercalation voltage, charge transfer and diffusion barrier of Li, it is found that the latter can be used as a better anode material from the perspective of insertion voltage and binding energy. At the same time, the former one is better in terms of diffusion barrier. Our study provides a comprehensive understanding on VS₂ based 2D anodes.

Abstract: The influence of hydrostatic pressure on the binding energy of hydrogenic impurity state in a wurtzite Al_yGa_1-yN/Al_xGa_1-xN parabolic quantum well and GaN/Al_xGa_1-xN square quantum well are studied using the variational method. The ground-state binding energies are presented as the functions of hydrostatic pressure, well width, composition and impurity center position. The anisotropic properties of the parameters in the system, and the changes (dependence) of electron effective mass, the dielectric constant, band gap with pressure and coordinate are considered in the numerical calculations. The results show that the hydrostatic pressure has obvious influence on the binding energy. The binding energy increase slowly with increasing the hydrostatic pressure p and the composition x, while the binding energy decrease significantly with increasing the well width and the position of impurity center. It is seen that the changing trends of the binding energy as a function of well width, pressure and the composition in the Al_yGa_1-yN/Al_xGa_1-xN parabolic quantum well are basically the same with that in the GaN/Al_xGa_1-xN square quantum well, but the changing trends of the binding energy as a function of impurity center position in the Al_yGa_1-yN/Al_xGa_1-xN parabolic quantum well are significantly greater than that in the GaN/Al_xGa_1-xN square quantum well.

Abstract: In this study, Al and N implantation effect on surface properties of 4H-SiC epitaxial layers were investigated before annealing process. AFM results indicated that all implanted samples indicated relatively low RMS roughness values. From UPS and XPS analysis, work function and Si-C binding energy of implanted samples were increased compared to the reference 4H-SiC sample. Those variations may be caused by lattice disorder and amorphization. In addition, TEM image showed damaged area in 4H-SiC epitaxial layer.

Abstract: The paper presents the results of modelling of phosphorus interaction with substitutional (Cr, Mn, P) and interstitial (C) impurity atoms in bcc iron in the framework of density functional theory using WIEN2k software. It is found that a repulsion exists of a phosphorus atom in the three first spheres of coordination of carbon, chromium and phosphorus atoms, while for manganese such repulsion of phosphorus takes place only in the second sphere. This repulsion is a consequence of an abrupt change of magnetic moment of manganese atom, so the solution energy of phosphorus almost does not change. On the contrary, chromium decreases phosphorus solubility in iron, in agreement with other data.

Abstract: To investigate the interaction mechanism of PVA on the surface of HA, the molecular dynamics simulation was applied to simulate and calculate the binding energy between PVA of different monomers and HA crystallographic planes (001), (100) and (110), and then the mechanical properties and radial distribution function of the PVA/HA(110) system were calculated and analyzed. The results show that HA (110) has the higher binding energy with PVA than that of HA (001) and (100). The binding energy and the Young’s modulus of HA(110)/PVA system increase with the rising of PVA monomer number at the same crystallographic plane in a certain range, however, the descending trend takes place while monomers number reaching a certain value. This change trend is relating to the effective contact between two single components. By calculating the pair correlation function of HA(110)/PVA, there is a strong interaction between HA crystallographic plane (110) and PVA, it is mainly derived from the hydrogen bonds between O atoms of PVA and H atoms in HA crystal, besides, the ionic bonds interactions existing between O_a and Ca.