Electronic and dielectric properties of silicene functionalized with monomers, dimers and trimers of B, C and N atoms

RSC Advances ◽  
2014 ◽  
Vol 4 (60) ◽  
pp. 31700-31705 ◽  
Author(s):  
Brij Mohan ◽  
Ashok Kumar ◽  
P. K. Ahluwalia
Keyword(s):  
Dielectric Properties ◽  
Band Gap ◽  
First Principle ◽  
First Principle Calculations ◽  
Gap Opening ◽  
C And N

First principle calculations have been performed to study the geometric, electronic and dielectric properties of low-buckled silicene with the adsorption of monomers, dimers and trimers of B, C and N atoms. A band gap opening has been achieved for all the C adsorbates, homo dimers of B and N, the hetero N–B dimer and the B–C–N trimer on silicene.

Electronic Structure Analyses of BN in Cubic and Hexagonal Phases

2011 ◽  
Vol 268-270 ◽  
pp. 1-3
Author(s):  
Ting Zhang ◽  
Ming He ◽  
Tao Chen ◽  
Guang Chang Wang
Keyword(s):  
Electronic Structure ◽  
Dielectric Properties ◽  
Plane Wave ◽  
Band Gap ◽  
Energy Band ◽  
First Principle ◽  
Energy Band Gap ◽  
First Principle Calculations ◽  
Two Phases ◽  
Valence Band Width

First principle calculations are performed on the structure, energy band gap, and dielectric properties of wurtzite and hexagonal BN by using a plane-wave pseudopotential method. It is found thath-BN has much narrower VB (valence band ) width and much sharper band edge than those ofw-BN. And the N 2sstates of the two phases of BN are dominant below 30.03 eV and the N 2pstates are dominant in the range between −20.62 and 20.32 eV.

scholarly journals Theoretical investigation of the vertical dielectric screening dependence on defects for few-layered van der Waals materials

RSC Advances ◽  
2019 ◽  
Vol 9 (69) ◽  
pp. 40309-40315 ◽  
Author(s):  
Amit Singh ◽  
Seunghan Lee ◽  
Hyeonhu Bae ◽  
Jahyun Koo ◽  
Li Yang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Theoretical Investigation ◽  
Van Der Waals ◽  
First Principle ◽  
First Principle Calculations ◽  
Dielectric Screening ◽  
Van Der Waals Materials

First-principle calculations were employed to analyze the effects induced by vacancies of molybdenum (Mo) and sulfur (S) on the dielectric properties of few-layered MoS2.

Theoretical Analysis of the DOS and Band Structural Properties of Ti1-XSnxO2 Solid Solutions

2012 ◽  
Vol 465 ◽  
pp. 33-36
Author(s):  
Zhi Dong Lin ◽  
Wen Long Song ◽  
Ju Cheng Zheng
Keyword(s):  
Band Gap ◽  
Solid Solutions ◽  
Density Functional ◽  
Wide Band ◽  
Low Energy ◽  
Low Density ◽  
First Principle ◽  
Wide Band Gap ◽  
Functional Theory ◽  
First Principle Calculations

The band structure and density of states (DOS) of Ti1-xSnxO2 solid solutions with x=0, 1/8, 1/4, 1/2 and 1 were investigated by means of the first-principle calculations based on density functional theory. The result indicated that band gap and Fermi level of TiO2-SnO2 vary continuously from those of pure TiO2 to those of Sn content increasing. In addition, the DOS moves towards low energy and the bang gap is broadened with growing value of x. The wide band gap and the low density of the states in the conduction band result in the enhancement of photoactivity in Ti1-xSnxO2.

Insight into sulfur vacancy-induced insulator to metal transition of Li2S

2017 ◽  
Vol 10 (05) ◽  
pp. 1750067 ◽  
Author(s):  
Yong Pan
Keyword(s):  
Band Gap ◽  
Conduction Band ◽  
Vacancy Concentration ◽  
First Principle ◽  
Sulfur Vacancy ◽  
First Principle Calculations ◽  
Metallic Bond ◽  
Charge Interaction ◽  
Carrier Trap ◽  
Insight Into

Sulfur vacancy-induced charge carrier trap is quite important for improving the insulating characteristic of Li2S. In this work, we apply the first-principle calculations to investigate the influence of sulfur intrinsic vacancy and sulfur vacancy concentration on the structure and conductivity of Li2S. Sulfur intrinsic vacancy is dynamically stable. Importantly, sulfur vacancy reduces the band gap of Li2S. The calculated band gap of sulfur intrinsic vacancy is 0.700[Formula: see text]eV. We suggest that the removed sulfur atom leads to Li-2[Formula: see text] state shift from conduction band to Fermi level and improves the charge overlap between the top of valence band (VB) and the bottom of conduction band (CB). The strong charge interaction of Li pairing atoms forms the Li–Li metallic bond. Finally, we predict that sulfur vacancy gives rise to the insulator to metal transition of Li2S. Our works open up a new possibility for improving the conductivity of Li2S.

Electronic Structures and Optical Properties of CuIn1-XGaXSe2 by First-Principle Calculations

2011 ◽  
Vol 239-242 ◽  
pp. 1304-1308
Author(s):  
Zong Bao Li
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Electronic Structures ◽  
First Principle ◽  
Quaternary Compound ◽  
Double Peak Structure ◽  
First Principle Calculations ◽  
Peak Structure ◽  
Small Band ◽  
Different Content

First-principle calculations on the electronic structures and optical properties of CuIn1-xGaxSe2(x=0, 0.25, 0.5, 0.75 and 1) reveal that CuIn1-xGaxSe2are small band gap materials and the ground state is stabiles from x=0 to 1 while the band-gap of the quaternary compound widen, all of that are in good agreement with the experimental results. We find that the obviously double peak structure of the imaginary of dielectric function centered about from 0.9 to 5.0 while a distinct peak appears at about 2.2eV and a smooth increasing with another peak appearing at about 5.5eV for the different content of Ga appearing in the absorption spectrum, all of which indicate the different band gap for the transition.

scholarly journals Excellent Infrared Nonlinear Optical Crystals BaMO(IO3)5 (M = V, Ta) Predicted by First Principle Calculations

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1809 ◽  
Author(s):  
Yingfeng Li ◽  
Mengqi Cui ◽  
Hejin Yan ◽  
Yangxin Yu ◽  
Meicheng Li ◽  
...  
Keyword(s):  
Band Gap ◽  
Nonlinear Optical ◽  
Second Harmonic ◽  
Damage Threshold ◽  
Laser Damage Threshold ◽  
First Principle ◽  
Nonlinear Optical Crystals ◽  
First Principle Calculations ◽  
Optical Crystals ◽  
Nlo Materials

Two nonlinear optical crystals, BaVO(IO3)5 and BaTaO(IO3)5, are designed by substituting Nb with V and Ta, respectively, in BaNbO(IO3)5, which is itself a recently synthesized infrared nonlinear optical (NLO) material. The designs of BaVO(IO3)5 and BaTaO(IO3)5 from BaNbO(IO3)5 are based on the following motivation: BaVO(IO3)5 should have a larger second-harmonic generation (SHG) coefficient than BaNbO(IO3)5, as V will result in a stronger second-order Jahn-Teller effect than Nb due to its smaller ion radius; at the same time, BaTaO(IO3)5 should have a larger laser-damage threshold, due to the fact that Ta has a smaller electronegativity leading to a greater band-gap. Established on reliable first-principle calculations, it is demonstrated that BaVO(IO3)5 has a much larger SHG coefficient than BaNbO(IO3)5 (23.42 × 10−9 vs. 18.66 × 10−9 esu); and BaTaO(IO3)5 has a significantly greater band-gap than BaNbO(IO3)5 (4.20 vs. 3.55 eV). Meanwhile, the absorption spectra and birefringences of both BaVO(IO3)5 and BaTaO(IO3)5 are acceptable for practice, suggesting that these two crystals can both be expected to be excellent infrared NLO materials.

Band gap engineering by anion doping in the photocatalyst BiTaO4: First principle calculations

2012 ◽  
Vol 37 (4) ◽  
pp. 3014-3018 ◽  
Author(s):  
Jawad Nisar ◽  
Baochang Wang ◽  
Carlos Moyses Araujo ◽  
Antonio Ferreira da Silva ◽  
Tae Won Kang ◽  
...  
Keyword(s):  
Band Gap ◽  
First Principle ◽  
Band Gap Engineering ◽  
Anion Doping ◽  
First Principle Calculations
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