Investigation on the Electronic Structure and Optical Properties of ZnO Nanofilms

2015 ◽  
Vol 713-715 ◽  
pp. 2731-2736
Author(s):  
Rui Zhang ◽  
Hong Sheng Zhao ◽  
Huan Ming Chen
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Absorption Edge ◽  
First Principles ◽  
Reflection Spectrum ◽  
Interband Transition ◽  
Single Layer ◽  
Different Thickness ◽  
Transition Absorption ◽  
Bonding Characteristic

The electronic structure and optical properties of wurtzite ZnO nanofilms with different thickness are investigated systematically by using the first-principles approach. The results indicate that the valence band properties of the ZnO nanofilms are mainly determined by the Zn: 3d state and O: 2p state. And its conduction band properties are determined by Zn: 4s state and Zn: 4p state. The band gap decreases with the thickness of nanofilms increasing in [0001] direction. It is also found that the interband transition absorption edge of ZnO nanofilms decreasing from 5.5 eV to 2.7 eV with the thickness of nanofilms increasing from single layer to five layers. The interband transition of reflection spectrum occurs mainly in the range of 10 eV to 18 eV, which is in line with the ionic bonding characteristic of wurtzite ZnO.

scholarly journals Optical Properties of Graphene/MoS2 Heterostructure: First Principles Calculations

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 962 ◽  
Author(s):  
Bin Qiu ◽  
Xiuwen Zhao ◽  
Guichao Hu ◽  
Weiwei Yue ◽  
Junfeng Ren ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Single Layer ◽  
Single Layer Graphene ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Layer Graphene ◽  
Two Dimensional Materials

The electronic structure and the optical properties of Graphene/MoS2 heterostructure (GM) are studied based on density functional theory. Compared with single-layer graphene, the bandgap will be opened; however, the bandgap will be reduced significantly when compared with single-layer MoS2. Redshifts of the absorption coefficient, refractive index, and the reflectance appear in the GM system; however, blueshift is found for the energy loss spectrum. Electronic structure and optical properties of single-layer graphene and MoS2 are changed after they are combined to form the heterostructure, which broadens the extensive developments of two-dimensional materials.

Electronic Structure and Optical Properties of a Mn-Doped InSe/WSe2 van der Walls Heterostructure: First Principles Calculations

2020 ◽  
Vol 77 (7) ◽  
pp. 587-591
Author(s):  
Rundong Liang ◽  
Xiuwen Zhao ◽  
Guichao Hu ◽  
Weiwei Yue ◽  
Xiaobo Yuan ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
First Principles Calculations ◽  
Mn Doped

Electronic Structure and Optical Properties of Non-Metals (N, F, P, Cl, S)-Doped Cubic NaTaO3 by Density Functional Theory

2009 ◽  
Vol 79-82 ◽  
pp. 1245-1248 ◽  
Author(s):  
Pei Lin Han ◽  
Xiao Jing Wang ◽  
Yan Hong Zhao ◽  
Chang He Tang
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Electronic Structure ◽  
Visible Light ◽  
Absorption Edge ◽  
Density Functional ◽  
Red Shift ◽  
Functional Theory ◽  
Photoactive Materials ◽  
Metal Doped

Electronic structure and optical properties of non-metals (N, S, F, P, Cl) -doped cubic NaTaO3 were investigated systematically by density functional theory (DFT). The results showed that the substitution of (N, S, P, Cl) for O in NaTaO3 was effective in narrowing the band-gap relative to the F-doped NaTaO3. The larger red shift of the absorption edge and the higher visible light absorption at about 520 nm were found for the (N and P)-doped NaTaO3. The excitation from the impurity states to the conduction band may account for the red shift of the absorption edge in an electron-deficiency non-metal doped NaTaO3. The obvious absorption in the visible light region for (N and P)-doped NaTaO3 provides an important guidance for the design and preparation of the visible light photoactive materials.

ELECTRONIC STRUCTURE AND OPTICAL PROPERTIES OF CRYSTALLINE C60

1992 ◽  
Vol 06 (06) ◽  
pp. 309-321 ◽  
Author(s):  
W.Y. CHING ◽  
MING-ZHU HUANG ◽  
YONG-NIAN XU ◽  
FANQI GAN
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Optical Spectrum ◽  
Local Density ◽  
Low Dielectric Constant ◽  
Experimental Measurements ◽  
Absorption Bands ◽  
Low Dielectric ◽  
Good Agreement

The electronic structure and optical properties of crystalline C 60 and their pressure dependence have been studied by first-principles local density calculations. It is shown that fcc C 60 has a low dielectric constant and an optical spectrum rich in structures. The spectrum shows five disconnected absorption bands in the 1.4 to 7.0 eV region with sharp structures in each band that can be attributed to critical point transitions. This is a manifestation of the localized molecular structure coupled with long range crystalline order unique to the C 60 crystal. At a sufficient high pressure, the structures in the optical spectrum start to merge due to the merging of the bands. These results are in good agreement with some recent experimental measurements.

First principles study of the structural, electronic and optical properties of crystalline o-phenanthroline

2016 ◽  
Vol 30 (14) ◽  
pp. 1650077 ◽  
Author(s):  
Hajar Nejatipour ◽  
Mehrdad Dadsetani
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Binding Energies ◽  
Many Body ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Independent Particle ◽  
Excitonic Effects ◽  
Comprehensive Study

In a comprehensive study, structural properties, electronic structure and optical response of crystalline o-phenanthroline were investigated. Our results show that in generalized gradient approximation (GGA) approximation, o-phenanthroline is a direct bandgap semiconductor of 2.60 eV. In the framework of many-body approach, by solving the Bethe–Salpeter equation (BSE), dielectric properties of crystalline o-phenanthroline were studied and compared with phenanthrene. Highly anisotropic components of the imaginary part of the macroscopic dielectric function in o-phenanthroline show four main excitonic features in the bandgap region. In comparison to phenanthrene, these excitons occur at lower energies. Due to smaller bond lengths originated from the polarity nature of bonds in presence of nitrogen atoms, denser packing, and therefore, a weaker screening effect, exciton binding energies in o-phenanthroline were found to be larger than those in phenanthrene. Our results showed that in comparison to the independent-particle picture, excitonic effects highly redistribute the oscillator strength.

Sign in / Sign up

Export Citation Format

Share Document