Energy Levels and Optical Properties of Trapped Electrons in 2‐Methyltetrahydrofuran

1966 ◽  
Vol 44 (8) ◽  
pp. 3140-3141 ◽  
Author(s):  
Kenji Fueki
Keyword(s):  
Optical Properties ◽  
Energy Levels ◽  
Trapped Electrons

Molecular Design and Application of a Photovoltaic Polymer with Improved Optical Properties and Molecular Energy Levels

2015 ◽  
Vol 48 (11) ◽  
pp. 3493-3499 ◽  
Author(s):  
Huifeng Yao ◽  
Hao Zhang ◽  
Long Ye ◽  
Wenchao Zhao ◽  
Shaoqing Zhang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Molecular Design ◽  
Energy Levels ◽  
Design And Application

Analysis of electronic structure and optical properties of N-doped SiO2 based on DFT calculations

2015 ◽  
Vol 29 (19) ◽  
pp. 1550100 ◽  
Author(s):  
Sui-Shuan Zhang ◽  
Zong-Yan Zhao ◽  
Pei-Zhi Yang
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Band Gap ◽  
Impurity Concentration ◽  
Nitrogen Concentration ◽  
Energy Levels ◽  
Optical Parameter ◽  
Doping Effects ◽  
N Doping ◽  
The Relationship

The crystal structure, electronic structure and optical properties of N-doped [Formula: see text] with different N impurity concentrations were calculated by density function theory within GGA[Formula: see text]+[Formula: see text]U method. The crystal distortion, impurity formation energy, band gap, band width and optical parameter of N-doped [Formula: see text] are closely related with N impurity concentration. Based on the calculated results, there are three new impurity energy levels emerging in the band gap of N-doped [Formula: see text], which determine the electronic structure and optical properties. The variations of optical properties induced by N doping are predominately determined by the unsaturated impurity states, which are more obvious at higher N impurity concentration. In addition, all the doping effects of N in both [Formula: see text]-quartz [Formula: see text] and [Formula: see text]-quartz [Formula: see text] are very similar. According to these findings, one could understand the relationship between nitrogen concentration and optical parameter of [Formula: see text] materials, and design new optoelectrionic Si–O–N compounds.

Energy Band Models for Spatially Dispersive Dielectric Media

1975 ◽  
Vol 53 (19) ◽  
pp. 2095-2122 ◽  
Author(s):  
J. E. Sipe ◽  
J. Van Kranendonk
Keyword(s):  
Optical Properties ◽  
Degrees Of Freedom ◽  
Energy Levels ◽  
Equations Of Motion ◽  
Dispersive Media ◽  
Energy Bands ◽  
Macroscopic Theory ◽  
Mechanical Coupling ◽  
Radiation Theory ◽  
Spatially Dispersive

The effects of spatial dispersion on the optical properties of dielectric crystals, arising from the broadening of the molecular energy levels into energy bands by the intermolecular interaction, are discussed both in the microscopic and the macroscopic theory. The microscopic equations of motion for the internal degrees of freedom describing the molecular excitations are derived using semiclassical radiation theory, and the conditions are given under which a description in terms of only the dipole moment is possible. The corresponding macroscopic equations are derived and the nature of the boundary conditions and integral relations appearing in the theory are discussed. The characterization of spatially dispersive media as nonlocal is shown to be based on a misinterpretation of the meaning of the integral kernels relating to infinite media. The breakdown of the macroscopic theory due to the previously predicted onset of an antiresonant response is explicitly demonstrated for slab geometries for which rigorous solutions are given of both the macroscopic and the microscopic equations. Finally, we introduce a mechanical coupling varying exponentially with the intermolecular separation, which provides a two parameter model for the exciton bands and which prevents the proliferation of microscopic refractive indices occurring in other models. The exp model is shown to be useful to study the dependence of the optical properties for example on the effective mass and the width of an exciton band.

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.

Electronic structures and optical properties of cuprous oxide and hydroxide

2014 ◽  
Vol 1675 ◽  
pp. 185-190
Author(s):  
Yunguo Li ◽  
Cláudio M. Lousada ◽  
Pavel A. Korzhavyi
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Cuprous Oxide ◽  
Density Functional ◽  
Spent Nuclear Fuel ◽  
Energy Levels ◽  
Chemical Properties ◽  
Density Functional Theory Calculations ◽  
Hybrid Functional ◽  
Indirect Band Gap

ABSTRACTThe broad range of applications of copper, including areas such as electronics, fuel cells, and spent nuclear fuel disposal, require accurate description of the physical and chemical properties of copper compounds. Within some of these applications, cuprous hydroxide is a compound whose relevance has been recently discovered. Its existence in the solid-state form was recently reported. Experimental determination of its physical-chemical properties is challenging due to its instability and poop crystallinity. Within the framework of density functional theory calculations (DFT), we investigated the nature of bonding, electronic spectra, and optical properties of the cuprous oxide and cuprous hydroxide. It is found that the hybrid functional PBE0 can accurately describe the electronic structure and optical properties of these two copper(I) compounds. The calculated properties of cuprous oxide are in good agreement with the experimental data and other theoretical results. The structure of cuprous hydroxide can be deduced from that of cuprous oxide by substituting half Cu+ in Cu2O lattice with protons. Compared to Cu2O, the presence of hydrogen in CuOH has little effect on the ionic nature of Cu–O bonding, but lowers the energy levels of the occupied states. Thus, CuOH is calculated to have a wider indirect band gap of 2.73 eV compared with the Cu2O band gap of 2.17 eV.

Density functional study on electric structure and optical properties in Na-doped 3C-SiC

2019 ◽  
Vol 33 (24) ◽  
pp. 1950288 ◽  
Author(s):  
Xuefeng Lu ◽  
Jianhua Luo ◽  
Panfeng Yang ◽  
Tingting Zhao ◽  
Junqiang Ren ◽  
...  
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Energy Levels ◽  
Functional Study ◽  
Na Doping ◽  
Difference Density ◽  
Density Maps ◽  
Charge Difference Density ◽  
Electric Structure ◽  
Energy Formula

Structural stability along with the electronic and the optical properties of intrinsic 3C-SiC, [Formula: see text] and [Formula: see text] are studied by the first-principles calculations. [Formula: see text] system possesses the most considerate stability with lowest binding energy [Formula: see text] and formation energy [Formula: see text] compared to [Formula: see text]. It is observed that the non-filled impurity energy levels in the vicinity of the Fermi level can subsequently give rise to an enhancement of electrical conductivity of 3C-SiC. Through the analysis of charge difference density maps, it is found that covalence of bonds between the Na atom and nearby C atom reduces in varying degrees. In different concentrations of Na doping systems, especially for the supercell of [Formula: see text], the real and imaginary parts of the dielectric constant are visibly added in the energy range of 0–0.5 eV, demonstrating that the dielectric loss property of the 3C-SiC is improved evidently. These features confirm that the Na-doped 3C-SiC semiconductor is propitious to the wide application of 3C-SiC in the field of absorbing materials.

Effects of germanium addition to copper phthalocyanine/fullerene-based solar cells

2012 ◽  
Vol 2 (2) ◽  
Author(s):  
Takeo Oku ◽  
Kazuma Kumada ◽  
Atsushi Suzuki ◽  
Kenji Kikuchi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Properties ◽  
Solar Cells ◽  
Copper Phthalocyanine ◽  
Energy Levels ◽  
Power Conversion ◽  
Analysis Data ◽  
Transmission Electron ◽  
Conversion Efficiencies

AbstractCopper phthalocyanine/fullerene-based solar cells were fabricated, and the electronic and optical properties were investigated. Effects of germanium addition to the solar cells were also investigated, which resulted in increase of power conversion efficiencies of the solar cells. Nanostructures of the solar cells were investigated by transmission electron microscopy and electron diffraction, which indicated formation of Ge compound nanoparticles in the copper phthalocyanine layers. Energy levels of the solar cells were discussed from the present analysis data.

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