Modeling Optical Properties of Small Metallic Nanoparticles Based on Density Functional Theory

2007 ◽  
Author(s):  
Yi He ◽  
Taofang Zeng
Keyword(s):  
Optical Properties ◽  
Metallic Nanoparticles ◽  
Density Functional ◽  
Local Density ◽  
Incident Light ◽  
Tight Binding ◽  
Local Density Of States ◽  
Functional Theory ◽  
Hamilton Matrix ◽  
Different Diameters

Optical properties of silver nanoparticles with different diameters are investigated based on the electronic structures of component silver atoms. Within the frame of tight binding method, the local density of states of each silver atom is obtained through a recursive approach that extracts the required information directly from the Hamilton matrix. Then the interaction between the electric field of incident light and electrons in the nanoparticles is simulated to characterize their optical features and the size effects were interpreted according the results.

Ab initio study of oxygen vacancy effects on electronic and optical properties of NiO

MRS Advances ◽  
2016 ◽  
Vol 1 (37) ◽  
pp. 2617-2622 ◽  
Author(s):  
John Petersen ◽  
Fidele Twagirayezu ◽  
Pablo D. Borges ◽  
Luisa Scolfaro ◽  
Wilhelmus Geerts
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Local Density ◽  
Optical Transition ◽  
Energy Levels ◽  
Density Functional Theory Calculations ◽  
Local Density Of States ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
O Vacancy

ABSTRACTDensity Functional Theory calculations of electronic and optical properties of NiO, with and without O vacancies, are the focus of this work. Two bands, one fully occupied and the other unoccupied, induced by an O vacancy, are found in the gap. These energy levels are identified and analyzed by means of a local density of states (LDOS) calculation, and notable crystal field splitting can be seen. The real and imaginary parts of the dielectric function are calculated, and an additional optical transition can be seen at lower energy, which can be attributed to the O vacancy induced state in the band gap.

Comparative density functional theory–density functional tight binding study of fullerene derivatives: effects due to fullerene size, addends, and crystallinity on band structure, charge transport and optical properties

2017 ◽  
Vol 19 (41) ◽  
pp. 28330-28343 ◽  
Author(s):  
Amrita Pal ◽  
Lai Kai Wen ◽  
Chia Yao Jun ◽  
Il Jeon ◽  
Yutaka Matsuo ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Solid State ◽  
Band Structure ◽  
Charge Transport ◽  
Density Functional ◽  
Tight Binding ◽  
Functional Theory ◽  
Fullerene Derivatives ◽  
Derivatives Of

Comparative DFT–DFTB study of multiple derivatives of C60 and C70 with different addends, in molecular and solid state.

Plasmonic resonances of nanoparticles from large-scale quantum mechanical simulations

2017 ◽  
Vol 31 (24) ◽  
pp. 1740003 ◽  
Author(s):  
Xu Zhang ◽  
Hongping Xiang ◽  
Mingliang Zhang ◽  
Gang Lu
Keyword(s):  
Density Functional Theory ◽  
Metallic Nanoparticles ◽  
Density Functional ◽  
Large Scale ◽  
Incident Light ◽  
Time Dependent ◽  
Coherent Motion ◽  
Quantum Mechanical ◽  
Functional Theory ◽  
Conduction Electrons

Plasmonic resonance of metallic nanoparticles results from coherent motion of its conduction electrons, driven by incident light. For the nanoparticles less than 10 nm in diameter, localized surface plasmonic resonances become sensitive to the quantum nature of the conduction electrons. Unfortunately, quantum mechanical simulations based on time-dependent Kohn–Sham density functional theory are computationally too expensive to tackle metal particles larger than 2 nm. Herein, we introduce the recently developed time-dependent orbital-free density functional theory (TD-OFDFT) approach which enables large-scale quantum mechanical simulations of plasmonic responses of metallic nanostructures. Using TD-OFDFT, we have performed quantum mechanical simulations to understand size-dependent plasmonic response of Na nanoparticles and plasmonic responses in Na nanoparticle dimers and trimers. An outlook of future development of the TD-OFDFT method is also presented.

Effect of strain on the electronic structure and optical properties of germanium

2018 ◽  
Vol 32 (12) ◽  
pp. 1850140 ◽  
Author(s):  
Shumin Wen ◽  
Chunwang Zhao ◽  
Jijun Li ◽  
Qingyu Hou
Keyword(s):  
Dielectric Constant ◽  
Optical Properties ◽  
Optical Conductivity ◽  
Density Functional ◽  
Tensile Strain ◽  
Local Density ◽  
Compressive Strain ◽  
Static Dielectric Constant ◽  
Functional Theory ◽  
Screened Exchange

The effects of biaxial strain parallel to the (001) plane on the electronic structures and optical properties of Ge are calculated using the first-principles plane-wave pseudopotential method based on density functional theory. The screened-exchange local-density approximation function was used to obtain more reliable band structures, while strain was changed from −4% to [Formula: see text]4%. The results show that the bandgap of Ge decreases with the increase of strain. Ge becomes a direct-bandgap semiconductor when the tensile strain reaches to 2%, which is in good agreement with the experimental results. The density of electron states of strained Ge becomes more localized. The tensile strain can increase the static dielectric constant distinctly, whereas the compressive strain can decrease the static dielectric constant slightly. The strain makes the absorption band edge move toward low energy. Both the tensile strain and compressive strain can significantly increase the reflectivity in the range from 7 eV to 14 eV. The tensile strain can decrease the optical conductivity, but the compressive strain can increase the optical conductivity significantly.

First-principles study of electronic and optical properties of solid-solution ZnO1−xSx

2017 ◽  
Vol 31 (23) ◽  
pp. 1750175 ◽  
Author(s):  
Margi Jani ◽  
Abhijit Ray
Keyword(s):  
Solid Solution ◽  
Density Functional Theory ◽  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Density Approximation ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Strong Localization

We investigated the electronic and optical properties of ZnO under the circumstances of isovalent anionic doping by sulfur. A pseudopotential implementation of density functional theory is applied within the local density approximation to examine the modification of band structure in wurtzite ZnO by sulfur substitution. Although Fermi level position does not change, a strong localization of Zn-[Formula: see text] orbital is found by S-doping. Optical properties and constants are found to strongly depend on the sulfur content at low photon energies.

Study of Structural, Electronic and Optical Properties of Lanthanum Doped Perovskite PZT Using Density Functional Theory

2017 ◽  
Vol 864 ◽  
pp. 127-132 ◽  
Author(s):  
N.H. Hussin ◽  
Mohamad Fariz Mohamad Taib ◽  
Mohd Hazrie Samat ◽  
N. Jon ◽  
Oskar Hasdinor Hassan ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Refractive Index ◽  
Optical Properties ◽  
Density Functional ◽  
Local Density ◽  
Ferroelectric Materials ◽  
Good Prediction ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Electronic And Optical Properties

Ferroelectric materials of lanthanum (La) doped PbZrTiO3 (PLZT) were investigated via first principles study. The structural, electronic and optical properties of PLZT in tetragonal structure (P4mm space group) were performed in the framework of density functional theory (DFT) with generalized gradient approximation (GGA) and local density approximation (LDA) methods. The calculated results of structural properties of PLZT were seen to be approximately close to the experimental data. The results of the electronic part were covered with the calculation of energy band gap and density of states (DOS). The highest valence band (VB) which lies at the Fermi level (EF) was dominated by the O 2p at F point. The conduction band (CB) of PLZT occurred at G point, which was primarily dominated by Ti 3d mixed at Pb and La p-state. Whereas the optical part was covered with the refractive index and absorption. The refractive index, n and the extinction coefficient, k were calculated with respect to photon energy. Those results obtained could be such a good prediction in studying parameters and properties of new materials.

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