The structural, electronic and optical properties of Au–ZnO interface structure from the first-principles calculation

2018 ◽  
Vol 32 (07) ◽  
pp. 1850107 ◽  
Author(s):  
Jin-Rong Huo ◽  
Lu Li ◽  
Hai-Xia Cheng ◽  
Xiao-Xu Wang ◽  
Guo-Hua Zhang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Density Of States ◽  
First Principles ◽  
Density Functional ◽  
Interface Structure ◽  
First Principles Calculation ◽  
Total Density ◽  
Electronic Density ◽  
Electronic And Optical Properties ◽  
Interface Structures

The interface structure, electronic and optical properties of Au–ZnO are studied using the first-principles calculation based on density functional theory (DFT). Given the interfacial distance, bonding configurations and terminated surface, we built the optimal interface structure and calculated the electronic and optical properties of the interface. The total density of states, partial electronic density of states, electric charge density and atomic populations (Mulliken) are also displayed. The results show that the electrons converge at O atoms at the interface, leading to a stronger binding of interfaces and thereby affecting the optical properties of interface structures. In addition, we present the binding energies of different interface structures. When the interface structure of Au–ZnO gets changed, furthermore, varying optical properties are exhibited.

Electronic and optical properties of pentagonal-B2C monolayer: A first-principles calculation

2017 ◽  
Vol 31 (08) ◽  
pp. 1750044 ◽  
Author(s):  
Mosayeb Naseri ◽  
Jafar Jalilian ◽  
A. H. Reshak
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Valence Band Maximum ◽  
First Principles Calculation ◽  
Electronic Band ◽  
Electronic And Optical Properties ◽  
Energy Consideration ◽  
Normal Light

The electronic and optical properties of pentagonal B2C (penta-B2C) monolayer are investigated by means of the first-principles calculations in the framework of the density functional theory. The cohesive energy consideration confirms the good stability of the B2C nanostructure in this phase. The electronic band structure reveals that the valence band maximum (VBM) is located at [Formula: see text]-point of the first Brillouin zone (BZ) whereas the conduction band minimum (CBM) is situated at the center of the BZ, resulting in an indirect energy bandgap of about 1.5 eV. Furthermore, a calculated low absorption and low reflection of the material in low energy ranges denote the transparency of the B2C monolayer in the investigated range for normal light incidence. The obtained results may find application in fabrication of future opto-electronic devices.

scholarly journals Study on Electronic and Optical Properties of Graphene Oxide Under an External Electric Field From First-principles

2021 ◽  
Author(s):  
Abdehafid Najim ◽  
Omar BAJJOU ◽  
Mustapha BOULGHALLAT ◽  
Mohammed Khenfouch ◽  
Khalid Rahmani
Keyword(s):  
Optical Properties ◽  
Graphene Oxide ◽  
Electric Field ◽  
Band Gap ◽  
External Electric Field ◽  
Density Of States ◽  
Density Functional ◽  
Partial Density ◽  
Total Density ◽  
Electronic And Optical Properties

Abstract Electronic and optical properties of graphene oxide (GO), under an external electric field (Eext) applied in three directions of space (x, y, z), are investigated using the density functional theory (DFT). The application of the Eext, causes a significant modifications to the electronic and optical properties of GO material. It has change the band gap, total density of states (TDOS), partial density of states (PDOS), absorption coefficient (α), dielectric function, optical conductivity, refractive index and loss function. The band gap of GO layer increases under the effects of the Eext, applied in x and y directions. On the other hand, for z direction, the band gap decreases by the effects of the Eext. The peaks of the TDOS around the Fermi level, change by the Eext applied in (x, y, z) directions. The α peaks of the GO sheet, decreases by the Eext applied in x direction, and increases if Eext applied in y and z directions. It is found that, the electronic and optical properties of GO layer, could be affected by the effects of the Eext and by its direction of application.

Effects of Sulfur Passivation on 6H-SiC(0001) Surface and Si/6H-SiC Interface

2016 ◽  
Vol 858 ◽  
pp. 185-188 ◽  
Author(s):  
Xiao Min He ◽  
Zhi Ming Chen ◽  
Lian Bi Li
Keyword(s):  
Density Of States ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculation ◽  
Covalent Bonds ◽  
Functional Theory ◽  
Binding Force ◽  
Sulfur Passivation ◽  
Specific Geometry ◽  
Interface Structures

The un-passivated and passivated 6H-SiC(0001) surface and Si(-220)/6H–SiC (0001) interface are investigated by first-principles calculation based on density functional theory. It is demonstrated that the surface energy of 6H-SiC(0001) surface with seven atom-layers converges well. When the surface is passivated with sulfur(S), the density of states decreases obviously, implying that the passivated 6H-SiC(0001) surface are more stable. Four specific geometry models of Si(-220)/6H–SiC(0001) interface structures with different terminations are chosen. The calculated adhesion energies suggest that, for un-passivated interface, the atomic binding force and interface stability of C-termination interface are stronger than Si-termination interface, while for passivated interface, the tendency is opposite. The calculations about the density of states of un-passivated interfacial suggest that the Si-Si covalent bonds are formed at Si-terminated interface, and that C-Si covalent bonds are formed at C-terminated interface. After the interface is passivated with S atoms, the interaction between Si and S atoms is observed.

scholarly journals First-Principles Studies for Electronic Structure and Optical Properties of Strontium Doped β-Ga2O3

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 348
Author(s):  
Loh Kean Ping ◽  
Mohd Ambri Mohamed ◽  
Abhay Kumar Mondal ◽  
Mohamad Fariz Mohamad Taib ◽  
Mohd Hazrie Samat ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Density Of States ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculation ◽  
Bandgap Energy ◽  
Structural Parameter ◽  
Monoclinic Space Group ◽  
Electron Charge Density

The crystal structure, electron charge density, band structure, density of states, and optical properties of pure and strontium (Sr)-doped β-Ga2O3 were studied using the first-principles calculation based on the density functional theory (DFT) within the generalized-gradient approximation (GGA) with the Perdew–Burke–Ernzerhof (PBE). The reason for choosing strontium as a dopant is due to its p-type doping behavior, which is expected to boost the material’s electrical and optical properties and maximize the devices’ efficiency. The structural parameter for pure β-Ga2O3 crystal structure is in the monoclinic space group (C2/m), which shows good agreement with the previous studies from experimental work. Bandgap energy from both pure and Sr-doped β-Ga2O3 is lower than the experimental bandgap value due to the limitation of DFT, which will ignore the calculation of exchange-correlation potential. To counterbalance the current incompatibilities, the better way to complete the theoretical calculations is to refine the theoretical predictions using the scissor operator’s working principle, according to literature published in the past and present. Therefore, the scissor operator was used to overcome the limitation of DFT. The density of states (DOS) shows the hybridization state of Ga 3d, O 2p, and Sr 5s orbital. The bonding population analysis exhibits the bonding characteristics for both pure and Sr-doped β-Ga2O3. The calculated optical properties for the absorption coefficient in Sr doping causes red-shift of the absorption spectrum, thus, strengthening visible light absorption. The reflectivity, refractive index, dielectric function, and loss function were obtained to understand further this novel work on Sr-doped β-Ga2O3 from the first-principles calculation.

Effects of vacancy on the electronic and optical properties of β-Si3N4 by first-principles

2019 ◽  
Vol 33 (36) ◽  
pp. 1950451
Author(s):  
Xuefeng Lu ◽  
Jianhua Luo ◽  
Panfeng Yang ◽  
Junqiang Ren ◽  
Xin Guo ◽  
...  
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Population Analysis ◽  
Perfect Crystal ◽  
Nitrogen Vacancy ◽  
First Principles Calculation ◽  
Electronic And Optical Properties ◽  
Charge Density Difference ◽  
Thermodynamic Conditions

We use a first-principles calculation to explore the effects of vacancies on structural, electronic and optical properties of [Formula: see text]-[Formula: see text] based on density functional theory (DFT). The results show that after optimization, the Si vacancy system of [Formula: see text]-[Formula: see text] is more difficult to produce than N vacancy system under the same thermodynamic conditions. The band gaps including N vacancy and Si vacancy systems are smaller than that of the perfect crystal. The charge density difference and population analysis show that the bonding near Si vacancy has stronger covalent property, whereas those near nitrogen vacancy have stronger ionic property. For Si vacancy system, the materials have much higher values of the imaginary part of the dielectric constant than those of N vacancies and perfect [Formula: see text]-[Formula: see text]. The maximum value of the Si vacancy system in absorption and reflection spectra is lower than those in different nitrogen vacancy systems.

First-Principles Study on Structural, Electronic and Optical Properties of TiO2 for Dye-Sensitized Solar Cells Photoanode

2016 ◽  
Vol 846 ◽  
pp. 719-725 ◽  
Author(s):  
Mohd Hazrie Samat ◽  
N.H. Hussin ◽  
Mohamad Fariz Mohamad Taib ◽  
M.K. Yaakob ◽  
Noor Syafiqah Samsi ◽  
...  
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Uv Light ◽  
Anatase Phase ◽  
Dye Sensitized Solar Cells ◽  
Total Density ◽  
Electronic And Optical Properties ◽  
Dye Sensitized ◽  
First Principles Study

First-principles study based on density functional theory (DFT) framework for structural, electronic and optical properties of titanium dioxide (TiO2) in anatase and rutile phases are investigated. Anatase phase exhibits wide band gap compare to rutile phase. The partial and total density of states for TiO2 (anatase and rutile) describes the occupying of titanium (Ti) and oxygen (O) atoms at each energy level. TiO2 has a high dielectric constant to avoid the recombination process while its high refractive index provides the efficient of light diffusion. The optical absorption of TiO2 occurs in ultraviolet (UV) light of the wavelength photon. The results from the first-principles calculations will be helpful to give an understanding about the properties of TiO2 as promising photoanode in dye-sensitized solar cell (DSSC).

First principles calculation of structural, electronic and optical properties of (001) and (110) growth axis (InN)/(GaN)n superlattices

2021 ◽  
Vol 67 (1 Jan-Feb) ◽  
pp. 7
Author(s):  
B. Bachir Bouiadjra ◽  
N. Mehnane ◽  
N. Oukli
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Scale Up ◽  
Energy Scale ◽  
First Principles Calculation ◽  
Full Potential ◽  
Electronic Band ◽  
Electronic And Optical Properties ◽  
Growth Axis

Based on the full potential linear muffin-tin orbitals (FPLMTO) calculation within density functional theory, we systematically investigate the electronic and optical properties of (100) and (110)-oriented (InN)/(GaN)n zinc-blende superlattice with one InN monolayer and with different numbers of GaN monolayers. Specifically, the electronic band structure calculations and their related features, like the absorption coefficient and refractive index of these systems are computed over a wide photon energy scale up to 20 eV. The effect of periodicity layer numbers n on the band gaps and the optical activity of (InN)/(GaN)n SLs in the both  growth axis (001) and (110) are examined and compared. Because of prospective optical aspects of (InN)/(GaN)n such as light-emitting applications, this theoretical study can help the experimental measurements.

scholarly journals Electronic and optical properties of vacancy ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; and X = Cl, Br, I): a first principles study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Faizan ◽  
K. C. Bhamu ◽  
Ghulam Murtaza ◽  
Xin He ◽  
Neeraj Kulhari ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
First Principles ◽  
Density Functional ◽  
Perovskite Solar Cells ◽  
Dielectric Constants ◽  
Maximum Efficiency ◽  
Exchange Potential ◽  
Double Perovskites ◽  
Electronic And Optical Properties

AbstractThe highly successful PBE functional and the modified Becke–Johnson exchange potential were used to calculate the structural, electronic, and optical properties of the vacancy-ordered double perovskites A2BX6 (A = Rb, Cs; B = Sn, Pd, Pt; X = Cl, Br, and I) using the density functional theory, a first principles approach. The convex hull approach was used to check the thermodynamic stability of the compounds. The calculated parameters (lattice constants, band gap, and bond lengths) are in tune with the available experimental and theoretical results. The compounds, Rb2PdBr6 and Cs2PtI6, exhibit band gaps within the optimal range of 0.9–1.6 eV, required for the single-junction photovoltaic applications. The photovoltaic efficiency of the studied materials was assessed using the spectroscopic-limited-maximum-efficiency (SLME) metric as well as the optical properties. The ideal band gap, high dielectric constants, and optimum light absorption of these perovskites make them suitable for high performance single and multi-junction perovskite solar cells.

scholarly journals First-Principles Calculation of Conductivity of Ce-C Codoped SnO2 Contacts

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Can Ding ◽  
Zhenjiang Gao ◽  
Xing Hu ◽  
Zhao Yuan
Keyword(s):  
Charge Density ◽  
Lattice Constant ◽  
First Principles ◽  
Density Functional ◽  
Energy Levels ◽  
Circuit Breaker ◽  
Enthalpy Change ◽  
First Principles Calculation ◽  
Contact Material ◽  
Electronic Density

The contact is the core element of the vacuum interrupter of the mechanical DC circuit breaker. The electrical conductivity and welding resistance of the material directly affect its stability and reliability. AgSnO2 contact material has low resistivity, welding resistance, and so on. This material occupies an important position of the circuit breaker contact material. This research is based on the first-principles analysis method of density functional theory. The article calculated the lattice constant, enthalpy change, energy band, electronic density of state, charge density distribution, population, and conductivity of Ce, C single-doped, and Ce-C codoped SnO2 systems. The results show that Ce, C single doping, and Ce-C codoping all increase the cell volume and lattice constant. When the elements are codoped, the enthalpy change is the largest, and the thermal stability is the best. It has the smallest bandgap, the most impurity energy levels, and the least energy required for electronic transitions. The 4f orbital electrons of the Ce atom and the 2p orbital electrons of C are the sources of impurity energy near the Fermi level. When the elements are codoped, more impurity energy levels are generated at the bottom of the conduction band and the top of the valence band. Its bandgap is reduced so conductivity is improved. From the charge density and population analysis, the number of free electrons of Ce atoms and C atoms is redistributed after codoping. It forms a Ce-C covalent bond to further increase the degree of commonality of electrons and enhance the metallicity. The conductivity analysis shows that both single-doped and codoped conductivity have been improved. When the elements are codoped, the conductivity is the largest, and the conductivity is the best.

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