Electronic structure modification in two-dimensional pentagonal PdS2 by external strain

2021 ◽  
Author(s):  
Mridu Sharma ◽  
Ranber Singh
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Valence Band ◽  
Electronic Structures ◽  
Two Dimensional ◽  
Structure Modification ◽  
Indirect Band Gap ◽  
D Orbitals ◽  
External Strain

We investigated the electronic structure modifications in two-dimensional (2D) pentagonal PdS<sub>2</sub> materials by external strains. In the absence of external strain the 2D pentagonal PdS<sub>2</sub> materials are indirect band gap semiconductors. The band gap decreases with an increase in the number of stacking PdS<sub>2</sub> monolayers. The external uniaxial and biaxial strains significantly modify the contributions of p-orbitals of S atoms and d-orbitals of Pd atoms to the conduction and valence band edges. It consequently modify the electronic structures of 2D pentagonal PdS<sub>2</sub> materials. This strain tunability of electronic structures of 2D pentagonal PdS<sub>2</sub> materials may be useful for their electro-mechanical applications.

scholarly journals Biaxial strain modulated the electronic structure of hydrogenated 2D tetragonal silicene

RSC Advances ◽  
2019 ◽  
Vol 9 (72) ◽  
pp. 42245-42251
Author(s):  
Haoran Tu ◽  
Jing Zhang ◽  
Zexuan Guo ◽  
Chunyan Xu
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Biaxial Strain ◽  
Direct Band Gap ◽  
Direct Band ◽  
Indirect Band Gap

Hydrogenation can open the band gap of 2D tetragonal silicene, α-SiH is semiconductors with a direct band gap of 2.436 eV whereas β-SiH is indirect band gap of 2.286 eV. The band gap of α-SiH, β-SiH and γ-SiH can be modulated via biaxial strain.

Tunable band gap of graphyne-based homo- and hetero-structures by stacking sequences, strain and electric field

2018 ◽  
Vol 20 (42) ◽  
pp. 26934-26946 ◽  
Author(s):  
Jiangni Yun ◽  
Yanni Zhang ◽  
Yanbing Ren ◽  
Manzhang Xu ◽  
Junfeng Yan ◽  
...  
Keyword(s):  
Electric Field ◽  
Band Gap ◽  
Electronic Structures ◽  
Vertical Electric Field ◽  
Tunable Band Gap ◽  
External Strain

Stacking sequences, external strain and a vertical electric field can be used to effectively modulate the electronic structures of graphyne-based homo- and hetero-structures.

First-principles studies on electronic structures and optical properties of two-dimensional Sn1−xTi(Zr)xS2 alloys

2018 ◽  
Vol 32 (07) ◽  
pp. 1850092 ◽  
Author(s):  
Dandan Li ◽  
Juan Du ◽  
Qian Zhang ◽  
Congxin Xia ◽  
Shuyi Wei
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
First Principles ◽  
Electronic Structures ◽  
Threshold Energy ◽  
Ternary Alloys ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Experimental Conditions ◽  
Part Formula

Through first-principles calculations we study the electronic structures and optical properties of two-dimensional (2D) Sn[Formula: see text]Ti(Zr)[Formula: see text]S2 alloys. The results indicate that the band gap value of Sn[Formula: see text]Ti(Zr)[Formula: see text]S2 alloys is decreased continuously when Ti(Zr) concentration is increased, which is very beneficial to optoelectronic devices applications. Moreover, the static dielectric constant is increased when the Ti(Zr) concentration is increased in the 2D Sn[Formula: see text]Ti(Zr)[Formula: see text]S2 alloys. In addition, we also calculate the imaginary part [Formula: see text] dispersion of Sn[Formula: see text]Ti(Zr)[Formula: see text]S2 alloys along the plane with different Ti(Zr) concentrations. The threshold energy values decrease with increasing Ti(Zr) concentrations in the Sn[Formula: see text]Ti(Zr)[Formula: see text]S2 ternary alloys. Moreover, the calculations of formation energy also indicate that these 2D alloys can be fabricated under some experimental conditions. These results suggest that Ti(Zr) substituting Sn atom is an efficient way to tune the band gap and optical properties of 2D SnS2 nanosheets.

scholarly journals Electronic structure, elasticity, Debye temperature and anisotropy of cubic WO 3 from first-principles calculation

2018 ◽  
Vol 5 (6) ◽  
pp. 171921 ◽  
Author(s):  
Xing Liu ◽  
Hui-Qing Fan
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Debye Temperature ◽  
Density Functional ◽  
Elastic Wave Velocity ◽  
Point Of View ◽  
First Principles Calculation ◽  
Shear Moduli ◽  
Charge Densities ◽  
Indirect Band Gap

The electron structure, elastic constant, Debye temperature and anisotropy of elastic wave velocity for cubic WO 3 are studied using CASTEP based on density functional theory. The optimized structure is consistent with previous work and the band gap is obtained by computing the electronic structure; the top of the valence band is not at the same point as the bottom of the conduction band, which is an indirect band-gap oxide. Electronic properties are studied from the calculation of band structure, densities of states and charge densities. The bulk and shear moduli, Young's modulus, hardness and Poisson's ratio for WO 3 are studied by the elastic constants. We calculated acoustic wave velocities in different directions and estimated the Debye temperature from the acoustic velocity. The anisotropy of WO 3 was analysed from the point of view of a pure wave and quasi wave.

scholarly journals Copper halide diselenium: predicted two-dimensional materials with ultrahigh anisotropic carrier mobilities

RSC Advances ◽  
2020 ◽  
Vol 10 (14) ◽  
pp. 8016-8026 ◽  
Author(s):  
Fazel Shojaei ◽  
Maryam Azizi ◽  
Zabiollah Mahdavifar ◽  
Busheng Wang ◽  
Gilles Frapper
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Two Dimensional ◽  
Copper Halide ◽  
New Class ◽  
Two Dimensional Materials ◽  
Bonding Properties ◽  
High Carrier ◽  
Indirect Band Gap ◽  
Very High

The physical and bonding properties of a new class of two-dimensional materials – CuXSe2 (X = Cl, Br) – are investigated using first-principles methods. 2D CuXSe2 are indirect band gap and possess extremely anisotropic and very high carrier mobilities.

Electronic Structure and Magnetic Properties of Iron Doped TiO2 (Rutile): XPS Measurements and CPA Calculations

2014 ◽  
Vol 215 ◽  
pp. 28-34 ◽  
Author(s):  
Michael A. Korotin ◽  
Nikolay A. Skorikov ◽  
Ernst Z. Kurmaev ◽  
Dmitry A. Zatsepin ◽  
Seif O. Cholakh
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Band Gap ◽  
Valence Band ◽  
Coherent Potential Approximation ◽  
Photoelectron Spectra ◽  
Cation Substitution ◽  
Spectral Features ◽  
Potential Approximation ◽  
X Ray

X-ray photoelectron spectra of TiO2:Fe are measured. Electronic structure and magnetic properties of rutile doped by iron are calculated in frames of the coherent potential approximation. The main experimental spectral features of TiO2:Fe such as heterovalent cation substitution (Fe3+→Ti4+), decreasing of the band gap value and appearance of additional features at the bottom and top of X-ray photoelectron spectra of valence band in comparison with those for undoped TiO2 are described.

Tunable band gap and magnetism of the two-dimensional nickel hydroxide

RSC Advances ◽  
2015 ◽  
Vol 5 (94) ◽  
pp. 77154-77158 ◽  
Author(s):  
Zhen-Kun Tang ◽  
Wei-Wei Liu ◽  
Deng-Yu Zhang ◽  
Woon-Ming Lau ◽  
Li-Min Liu
Keyword(s):  
Magnetic Properties ◽  
Band Gap ◽  
Nickel Hydroxide ◽  
First Principles ◽  
Electronic Structures ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Tunable Band Gap

The electronic structures and magnetic properties of two dimensional (2D) hexagonal Ni(OH)2 are explored based on first-principles calculations.

Electronic Structure of Mercury, Gold and Platinum Impurities in Silicon

1985 ◽  
Vol 46 ◽  
Author(s):  
Jose R. Leite ◽  
Jose L.A. Alves
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Valence Band ◽  
Electronic Structures ◽  
Cluster Model ◽  
Tetrahedral Site ◽  
Shallow Donor ◽  
Molecular Cluster ◽  
Vacancy Model ◽  
Isoelectronic Impurities

AbstractThe electronic structures of substitutional and tetrahedral-site interstitial Hg+, Auo and Pt− isoelectronic impurities in silicon have been analysed. The centers are theoretically described by the Watson-sphereterminated molecular cluster model within the framework of the multiplescattering Xa formalism. At the substitutional sites the centers are related to the “vacancy” model recently proposed to describe the properties of the elements at the end of the transition-metal series. At the interstitialsites the impurities introduce a hyperdeep s-like level close to the bottom of the valence band and, in agreement with experiments, do not show shallow donor activities. For all the analysed centers the d-states remain fully occupied below, or within, the valence band.

Two-Dimensional Electronic Structures in Layered Oxychalcogenide Semiconductors, LaCuOCh (Ch=S, Se, Te) and La2CdO2Se2

2004 ◽  
Vol 811 ◽  
Author(s):  
Toshio Kamiya ◽  
Kazushige Ueda ◽  
Hidenori Hiramatsu ◽  
Hiromichi Ohta ◽  
Masahiro Hirano ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electronic Structures ◽  
Orbit Interaction ◽  
Spin Orbit ◽  
Two Dimensional ◽  
Optical Absorption Spectra ◽  
Excitonic Absorption ◽  
Dimensional Network ◽  
Optical And Electronic Properties ◽  
Valence Bands

ABSTRACTElectronic structures of layered oxychalcogenides, LaCuOCh (Ch=S, Se, Te) and La2CdO2Se2, were studied using ab-initio band calculations in relation to their optical and electronic properties. It was found that the dispersions of the top valence bands are much smaller in Γ-Z direction than in Γ-X direction, indicating that the electronic structure is highly two-dimensional, and that holes are confined in the CuCh or CdSe layers. The two-dimensional electronic structure is supported experimentally by staircase-like structure observed in optical absorption spectra at 10 K associated with two excitonic absorption peaks split by spin-orbit interaction of Ch ions. La2CdO2Se2has the largest bandgap due to the two-dimensional network structure of CdSe tetrahedra.

Electronic Structure of Defects in SnTe

2013 ◽  
Vol 701 ◽  
pp. 125-130
Author(s):  
Salameh Ahmad
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Valence Band ◽  
Fundamental Difference ◽  
Density Of State ◽  
Defect States ◽  
Deep Defect ◽  
Conduction Bands ◽  
Resonant States ◽  
Structure Calculations

Myab initioelectronic structure calculations inRSn2n-1Te2n, n=16, R = a vacancy, Cd, and In show that when Sn atom is substituted by R, the Density of State (DOS) of the valence and conduction bands get strongly perturbed. There are significant changes near the band gap region. Sn vacancy causes very little change near the bottom of the conduction band DOS whereas there is an increase in the DOS near the top of the valence band. Results for In impurity shows that, unlike PbTe, the deep defect states in SnTe are resonant states near the top of the valence band. In PbTe these deep defect states lie in the band-gap region (act asn-type). This fundamental difference in the position of the deep defect states in SnTe and PbTe explains the experimental anomalies seen in the case of In impurities (act asn-type in PbTe andp-type in SnTe).

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