Electronic structures and optical properties of IV A elements-doped 3C-SiC from density functional calculations

Electronic structures and optical properties of IV A elements (Ge, Sn and Pb)-doped 3C-SiC are investigated by means of the first-principles calculation. The results reveal that the structure of Ge-doped system is more stable with a lower formation energy of 1.249 eV compared with those of Sn- and Pb-doped 3C-SiC systems of 3.360 eV and 5.476 eV, respectively. Doping of the IV A elements can increase the band gap, and there is an obvious transition from an indirect band gap to a direct band gap. Furthermore, charge difference density analysis proves that the covalent order of bonding between the doping atoms and the C atoms is Ge–C [Formula: see text] Sn–C [Formula: see text] Pb–C, which is fully verified by population values. Due to the lower static dielectric constant, the service life of 3C-SiC dramatically improved in production practice. Moreover, the lower reflectivity and absorption peak in the visible region, implying its wide application foreground in photoelectric devices.

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Stable GaSe-Like Phosphorus Carbide Monolayer with Tunable Electronic and Optical Properties from Ab Initio Calculations

Materials ◽

10.3390/ma11101937 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1937 ◽

Cited By ~ 5

Author(s):

Xiaolin Cai ◽

Zhili Zhu ◽

Weiyang Yu ◽

Chunyao Niu ◽

Jianjun Wang ◽

...

Keyword(s):

Optical Properties ◽

Band Gap ◽

Electronic Structures ◽

Density Functional ◽

Promising Candidate ◽

Functional Theory ◽

Electronic And Optical Properties ◽

Direct Band Gap ◽

Direct Band ◽

Indirect Band Gap

On the basis of density functional theory (DFT) calculations, we propose a stable two-dimensional (2D) monolayer phosphorus carbide (PC) with a GaSe-like structure, which has intriguing electronic and optical properties. Our calculated results show that this 2D monolayer structure is more stable than the other allotropes predicted by Tománek et al. [Nano Lett., 2016, 16, 3247–3252]. More importantly, this structure exhibits superb optical absorption, which can be mainly attributed to its direct band gap of 2.65 eV. The band edge alignments indicate that the 2D PC monolayer structure can be a promising candidate for photocatalytic water splitting. Furthermore, we found that strain is an effective method used to tune the electronic structures varying from direct to indirect band-gap semiconductor or even to metal. In addition, the introduction of one carbon vacancy in such a 2D PC structure can induce a magnetic moment of 1.22 µB. Our findings add a new member to the 2D material family and provide a promising candidate for optoelectronic devices in the future.

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First-principles studies of pure and fluorine substituted alanines

International Journal of Modern Physics B ◽

10.1142/s021797921650079x ◽

2016 ◽

Vol 30 (14) ◽

pp. 1650079 ◽

Cited By ~ 5

Author(s):

Sardar Ahmad ◽

Hamide Vaizie ◽

H. A. Rahnamaye Aliabad ◽

Rashid Ahmad ◽

Imad Khan ◽

...

Keyword(s):

Optical Properties ◽

Band Gap ◽

Density Functional ◽

Structural Parameters ◽

Wide Band ◽

Electromagnetic Spectrum ◽

Orthorhombic Crystal ◽

Orthorhombic Crystal Structure ◽

Direct Band ◽

Indirect Band Gap

This paper communicates the structural, electronic and optical properties of L-alanine, monofluoro and difluoro substituted alanines using density functional calculations. These compounds exist in orthorhombic crystal structure and the calculated structural parameters such as lattice constants, bond angles and bond lengths are in agreement with the experimental results. L-alanine is an indirect band gap insulator, while its fluorine substituted compounds (monofluoroalanine and difluoroalanine) are direct band gap insulators. The substitution causes reduction in the band gap and hence these optically tailored direct wide band gap materials have enhanced optical properties in the ultraviolet (UV) region of electromagnetic spectrum. Therefore, optical properties like dielectric function, refractive index, reflectivity and energy loss function are also investigated. These compounds have almost isotropic nature in the lower frequency range while at higher energies, they have a significant anisotropic nature.

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Band gap tuning from an indirect EuGa2S4 to a direct EuZnGeS4 semiconductor: syntheses, crystal and electronic structures, and optical properties

RSC Advances ◽

10.1039/c6ra25283d ◽

2017 ◽

Vol 7 (9) ◽

pp. 5039-5045 ◽

Cited By ~ 9

Author(s):

Yang Chi ◽

Sheng-Ping Guo ◽

Huai-Guo Xue

Keyword(s):

Optical Properties ◽

Band Gap ◽

Electronic Structures ◽

Direct Band Gap ◽

Simple Substitution ◽

Direct Band ◽

Indirect Band Gap ◽

Band Gap Tuning

Novel EuZnGeS4, with a direct band gap, can be obtained via simple substitution from EuGa2S4, with an indirect band gap.

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STRUCTURAL PARAMETERS AND OPTOELECTRONIC PROPERTIES OF Mg-IV-V2 (IV=Si, Ge, Sn AND V=P, As) COMPOUNDS

Surface Review and Letters ◽

10.1142/s0218625x18501081 ◽

2018 ◽

Vol 25 (05) ◽

pp. 1850108 ◽

Cited By ~ 1

Author(s):

M. IBRAHIM ◽

HAYAT ULLAH ◽

SAEED ULLAH JAN ◽

MANZAR ALI ◽

M. GULBAHAR ASHIQ

Keyword(s):

Optical Properties ◽

Band Gap ◽

Density Functional ◽

Structural Parameters ◽

Visible Region ◽

Functional Theory ◽

Lattice Constants ◽

Direct Band Gap ◽

Semiconductor Behavior ◽

Direct Band

Semiconductors are the backbone of the optoelectronic industry. Direct band gap materials in the visible energy region are highly desirable for the efficient optoelectronic applications. In this work, we have probed the structural, electronic and optical properties of Mg-IV-V2 (IV[Formula: see text]Si, Ge, Sn and V[Formula: see text]P, As) compounds by FP-LAPW calculations, based on density functional theory. Their crystal structure is chalcopyrite with space group of I-42d. The lattice constants of MgSiP2, MgSiAs2 and MgGeAs2 are consistent with experimental results. These compounds show semiconductor behavior with direct band gap ranging from 1.3–2.15[Formula: see text]eV. Optical properties were also investigated. Optical properties include real and imaginary parts of dielectric constant, energy loss function, refraction and reflection. Direct band gap nature and good response in the visible region of these compounds predict their usefulness in optoelectronic devices.

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Strain and Electric Field Modulated Indirect to Direct Band Transition of Monolayer GaInS2

10.21203/rs.3.rs-711661/v1 ◽

2021 ◽

Author(s):

Atanu Betal ◽

Jayanta Bera ◽

Satyajit Sahu

Keyword(s):

Optical Properties ◽

Electric Field ◽

Band Gap ◽

Density Functional ◽

Compressive Strain ◽

Direct Band Gap ◽

Td Dft ◽

Direct Band ◽

Band Transition ◽

Indirect Band Gap

Abstract Strain and electric field dependent electronic and optical properties have been calculated using density functional theory (DFT) and time-dependent DFT (TD-DFT) for GaInS2 monolayer. GaInS2 monolayer shows an indirect band gap of 1.79 eV where valance band maxima (VBM) and conduction band maxima (CBM) rest between K and Γ point and at Γ point, respectively. Under a particular tensile strain (8%), a phase change from semiconductor to semimetal has been noticed. While at 4% compressive strain, the material changes from indirect to direct band gap of 2.22 eV having VBM and CBM at Γ point. With further increase in compressive strain, CBM shifted from Γ to M point, which leads to an indirect band gap again. The electric field also affects the band structure of monolayer GaInS2 and shows the transition between indirect to direct band gap at positive electric field of 4 V/nm, which acts normal to the surface. The strain-dependent optical properties are also calculated, which suggests that the absorption coefficient increases with compressive strain.

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First Principles Study of Electronic and Optical Properties of Pristine and X (Cu, Ag And Au) Doped BiOBr

Journal of Institute of Science and Technology ◽

10.3126/jist.v22i2.19595 ◽

2018 ◽

Vol 22 (2) ◽

pp. 63-69 ◽

Cited By ~ 1

Author(s):

Samir Paudel ◽

Puspa Raj Adhikari ◽

Om Prakash Upadhyay ◽

Gopi Chandra Kaphle ◽

Anurag Srivastava

Keyword(s):

Optical Properties ◽

Band Gap ◽

First Principles ◽

Electronic Structures ◽

Density Functional ◽

Generalized Gradient ◽

Functional Theory ◽

Ab Initio Approach ◽

Indirect Band Gap ◽

Standard Density

The electronic structures and optical properties of pristine BiOBr and Cu, Ag and Au doped BiOBr have been analyzed by using a standard density functional theory based ab-initio approach employing generalized gradient approximation through revised Perdew Burke Ernzerhoff type parameterization. The calculation shows that both the doped and pristine BiOBr have indirect band gap, the band gap of the pristine BiOBr found 2.22eV, whereas band gap significantly reduced after doping Cu, Ag and Au on BiOBr. The band gap of Cu, Ag and Au doped BiOBr are 1.2eV, 0.9eV and 1.76eV respectively. The optical properties have been studied through dielectric function, both pure and doped BiOBr shows anisotropic nature. Journal of Institute of Science and TechnologyVolume 22, Issue 2, January 2018, page: 63-69

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Properties of Novel Non-Silicon Materials for Photovoltaic Applications: A First-Principle Insight

Materials ◽

10.3390/ma11102006 ◽

2018 ◽

Vol 11 (10) ◽

pp. 2006 ◽

Cited By ~ 3

Author(s):

Murugesan Rasukkannu ◽

Dhayalan Velauthapillai ◽

Federico Bianchini ◽

Ponniah Vajeeston

Keyword(s):

Band Gap ◽

Density Functional ◽

Crystalline Silicon ◽

Visible Region ◽

Initial Population ◽

First Principle ◽

Direct Band Gap ◽

Depth Analysis ◽

Photovoltaic Applications ◽

Direct Band

Due to the low absorption coefficients of crystalline silicon-based solar cells, researchers have focused on non-silicon semiconductors with direct band gaps for the development of novel photovoltaic devices. In this study, we use density functional theory to model the electronic structure of a large database of candidates to identify materials with ideal properties for photovoltaic applications. The first screening is operated at the GGA level to select only materials with a sufficiently small direct band gap. We extracted twenty-seven candidates from an initial population of thousands, exhibiting GGA band gap in the range 0.5–1 eV. More accurate calculations using a hybrid functional were performed on this subset. Based on this, we present a detailed first-principle investigation of the four optimal compounds, namely, TlBiS2, Ba3BiN, Ag2BaS2, and ZrSO. The direct band gap of these materials is between 1.1 and 2.26 eV. In the visible region, the absorption peaks that appear in the optical spectra for these compounds indicate high absorption intensity. Furthermore, we have investigated the structural and mechanical stability of these compounds and calculated electron effective masses. Based on in-depth analysis, we have identified TlBiS2, Ba3BiN, Ag2BaS2, and ZrSO as very promising candidates for photovoltaic applications.

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

Royal Society Open Science ◽

10.1098/rsos.171921 ◽

2018 ◽

Vol 5 (6) ◽

pp. 171921 ◽

Cited By ~ 5

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.

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First-principles investigation of the structural, elastic, electronic, and optical properties of semiconducting AgBr1–xIx (0 ≤ x ≤ 1) ternary alloys in rock-salt and zinc blende structures

Canadian Journal of Physics ◽

10.1139/cjp-2019-0357 ◽

2020 ◽

Vol 98 (9) ◽

pp. 834-848

Author(s):

H. Rekab-Djabri ◽

Mohamed Drief ◽

Manal M. Abdus Salam ◽

Salah Daoud ◽

F. El Haj Hassan ◽

...

Keyword(s):

Optical Properties ◽

Band Gap ◽

Rock Salt ◽

Density Functional ◽

Local Density ◽

Ternary Alloys ◽

Full Potential ◽

Zinc Blende ◽

Lmto Method ◽

Direct Band

In this work, first principle calculations of the structural, electronic, elastic, and optical properties of novel AgBr1–xIx ternary alloys in rock-salt (B1) and zinc-blende (B3) structures are presented. The calculations were performed using the full-potential linear muffin-tin orbital (FP-LMTO) method within the framework of the density functional theory (DFT). The exchange and correlation potentials were treated according to the local density approximation (LDA). The lattice constants for the B1 and B3 phases versus iodide concentration (x) were found to deviate slightly from the linear relationship of Vegard’s law. The calculated electronic properties showed that AgBr1–xIx alloys in the B3 structure have a direct band gap (Γ – Γ) for all concentrations of x, which means that they can be used in long-wavelength optoelectronic applications, while in the B1 structure they have an indirect (Γ – R) band gap. The elastic constants Cij, shear modulus G, Young’s modulus E, Poisson’s ratio ν, index of ductility B/G, sound velocities vt, vl, and vm, and Debye temperature θD were also reported and analyzed. By incorporating the basic optical properties, we discussed the dielectric function, refractive index, optical reflectivity, absorption coefficient, and optical conductivity in terms of incident photon energy up to 13.5 eV. The present results were found to be in good agreement with the available experimental and other theoretical results.

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SHIFT OF BAND GAP FROM DIRECT TO INDIRECT AND OPTICAL RESPONSE OF LiF UNDER PRESSURE

Modern Physics Letters B ◽

10.1142/s0217984913500619 ◽

2013 ◽

Vol 27 (09) ◽

pp. 1350061 ◽

Cited By ~ 12

Author(s):

A. SAJID ◽

G. MURTAZA ◽

A. H. RESHAK

Keyword(s):

Refractive Index ◽

Optical Properties ◽

Band Gap ◽

Lithium Fluoride ◽

Pressure Range ◽

Pressure Effect ◽

Indirect Transition ◽

Direct Band Gap ◽

Direct Band ◽

Indirect Band Gap

We hereby are reporting the transition pressure at which lithium fluoride ( LiF ) compound transforms from direct band gap to indirect band gap insulator on the basis of FP-LAPW calculations. The fundamental band gap of LiF compound suffers direct to indirect transition at a pressure of 70 GPa. The study of the pressure effect on the optical properties e.g. dielectric function, reflectivity, refractive index and optical conductivity of LiF in the pressure between 0–100 GPa, shows that this pressure range is very critical for LiF compound as there are significant changes in the optical properties of this compound.

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