Field-modulated low-energy electronic and optical properties of armchair silicene nanoribbons

2017 ◽  
Vol 85 ◽  
pp. 117-124 ◽  
Author(s):  
Feng-Lin Shyu
Keyword(s):  
Optical Properties ◽  
Low Energy ◽  
Electronic And Optical Properties ◽  
Silicene Nanoribbons

Exploration on electronic and optical properties of two-dimensional GaN-doped with Be, Mg, Zn

2020 ◽  
Vol 34 (20) ◽  
pp. 2050195
Author(s):  
Gang Li ◽  
Lei Liu ◽  
Jian Tian
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Of States ◽  
First Principles ◽  
High Energy ◽  
Low Energy ◽  
Two Dimensional ◽  
Electronic And Optical Properties ◽  
Type Semiconductor ◽  
P Type

To explore the variation on p-type-doped two-dimensional GaN, we calculate electronic and optical properties of buckled two-dimensional GaN-doped with p-type doping elements including Be, Mg and Zn atom by using first-principles. The results indicate that doping process of two-dimensional GaN after Be is most easily compared with Mg- and Zn-doped models. Band of doped two-dimensional GaN moves toward high energy end and it becomes a p-type semiconductor from the results of band structure and density of states, which may be caused by orbitals hybridization from dopants. Band gap and work function of doped two-dimensional GaN are both declined, which is beneficial for escape of electrons. Analysis of optical properties shows that they are sensitive and adjustable in doped two-dimensional GaN. Doping of Be, Mg and Zn atoms would have an important effect on optical characteristics of two-dimensional GaN at low-energy region.

Ab initio calculations of electronic and optical properties in O-doped LiF crystal

Open Physics ◽  
2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Meili Guo ◽  
Xiaodong Zhang ◽  
Hongen Gu ◽  
Na Wang
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Optical Constants ◽  
Wide Band ◽  
Low Energy ◽  
Experimental Result ◽  
First Principle ◽  
Wide Band Gap ◽  
Electronic And Optical Properties

AbstractWe present a first-principle study of electronic and optical properties in pure LiF and O-doped LiF crystals. The pure LiF crystal exhibits a wide band gap while the O-doped LiF crystal shows the less band gap due to the contribution of O 2p. Some optical constants, such as dielectric functions, reflectivity and the refractive index, have been performed. The calculated reflectivity and refractive index from the pure LiF crystal agree with the experimental and recently calculated results in the low-energy range. Meanwhile, the optical properties have also been predicted from the O-doped LiF crystal. The absorption band in 200 nm has been observed, which is relatively close to the experimental result.

scholarly journals Electronic and optical properties of Ba(1-x)Ca(x) TiO3 and Ba(1-x)Sr(x)TiO3

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
A. Belaaraj ◽  
O. Tahiri ◽  
S. Kassou ◽  
R. El Mrabet
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Low Energy ◽  
Band Gaps ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Densities Of States ◽  
Indirect Band Gap

The effect of Ca and Sr-doping on the structural electronic and optical properties of the cubic Ba1-xCaxTiO3 and Ba1-xSrxTiO3 (x=0.4, 0.6) mixed crystals was investigated using first-principles calculations based on density functional theory (DFT). The calculated band structures based on the optimized geometry of the cell for the solid solutions show an indirect band gap character at M-points, with low energy dispersion along height symmetry directions in the Brillouin zone. The band gaps increase with Ca and Sr concentrations. The total and partial densities of states were analyzed to examine the contribution of different orbitals to the maximum of valence band and the minimum of the conduction band. The optical properties such as reflectivity, energy loss, refractive index and extinction coefficient were studied. #DFT_calculations #band_gap #density_of_states #optical_properties

Electronic and Optical Properties of Sn-Doped Zno with and without O Vacancy

2014 ◽  
Vol 576 ◽  
pp. 9-13
Author(s):  
Xiao Chun Lai ◽  
Yi Bin Hou ◽  
Zhen Hui Sun ◽  
Lan Li Chen
Keyword(s):  
Optical Properties ◽  
Fermi Level ◽  
First Principles ◽  
Electron Transition ◽  
Low Energy ◽  
Optical Absorption Edge ◽  
Electronic And Optical Properties ◽  
Sn Doping ◽  
Doped Zno ◽  
O Vacancy

A systematic study on electronic and optical properties of Sn-doped ZnO with and without O vacancy has been performed using first-principles method. Our results revealed that the band gap of Sn-doped ZnO without O vacancy become narrow, demonstrating as red-shift and the electrons near the Fermi level originates from the delocalized Sn-5s. However, as O vacancy is introduced, Sn-5p states locate near the Fermi level. Furthermore, it is found that the optical absorption edge has been obviously changed after Sn doping in ZnO with and without O vacancy. Interestingly, in the low energy region, one new peak is observed for Sn-doped ZnO with O vacancy, due to the electron transition between Sn-5p and O-2p. The calculated results identify that O vacancy can improve the absorption of the visible light in Sn-doped ZnO.

scholarly journals Twisted Bilayer Graphene: Low‐Energy Physics, Electronic and Optical Properties

2019 ◽  
pp. 177-231 ◽  
Author(s):  
Gonçalo Catarina ◽  
Bruno Amorim ◽  
Eduardo V. Castro ◽  
Eduardo V. Castro ◽  
Eduardo V. Castro ◽  
...  
Keyword(s):  
Optical Properties ◽  
Bilayer Graphene ◽  
Low Energy ◽  
Electronic And Optical Properties ◽  
Twisted Bilayer Graphene ◽  
Energy Physics

Modulation of the optical properties of zigzag silicene nanoribbons by double carbon chains

2020 ◽  
Vol 98 (3) ◽  
pp. 260-265
Author(s):  
Dao-Bang Lu ◽  
Yu-Ling Song ◽  
Xiao-yu Huang
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
First Principles Calculations ◽  
Ribbon Width ◽  
Defect States ◽  
Electronic And Optical Properties ◽  
Carbon Chains ◽  
Electron Transitions ◽  
Width Direction ◽  
Silicene Nanoribbons

Using first-principles calculations, we investigate the electronic and optical properties of zigzag silicene nanoribbons substituted with double carbon chains. The results show that the chains are pulled nearly straight and produce a rather obvious transverse contraction in the width direction of the ribbon. The double carbon chains introduce defect states that appear as two degenerate bands across the Fermi level. These nanoribbons are always metallic regardless of the position of the carbon chains or the ribbon width. Under the same bandwidth, the imaginary parts of the dielectric functions in the Ex and Ey directions reveal red- and blue-shifts, respectively, with increasing distance between the two C chains. The imaginary parts of the dielectric functions in the Ex and Ey directions reveal blue- and redshifts, respectively, with increasing ribbon width. Three major peaks in the imaginary part of the dielectric function correspond to the intrinsic plasma frequencies originating from electron transitions of silicon and carbon. Such excellent electronic and optical properties may lead to some important applications of the nanoribbons in short-wavelength optoelectronic devices.

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