Band-gap tuning and optical response of two-dimensional<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Si</mml:mi><mml:mi>x</mml:mi></mml:msub><mml:msub><mml:mi mathvariant="normal">C</mml:mi><mml:mrow><mml:mn>1</mml:mn><mml:mtext>−</mml:mtext><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>: A first-principles real-space study of disordered two-dimensional materials

Sadhukhan, Banasree; Singh, Prashant; Nayak, A.; Datta, Sujoy; Johnson, Duane D.; Mookerjee, Abhijit

doi:10.1103/physrevb.96.054203

Cited by 15 publications

(11 citation statements)

References 74 publications

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“…Tight-binding-Linearized Muffin-tin Orbital Method: We use the van Leeuwen-Baerends corrected LDA exchange (LDA+vLB) [54][55][56][57][58][59][60] with the exchange-correlation energy parameterization [61]. An improved ASA basis of TB-LMTO [62] includes atomic spheres and empty spheres (ESs).…”

Section: Density-functional Theory Methodsmentioning

confidence: 99%

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Effect of substitutional doping and disorder on the phase stability, magnetism, and half-metallicity of Heusler alloys

Zarkevich,

Singh,

Smirnov

et al. 2021

Preprint

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Spintronics is the fast growing field that will play a key role in optimizing power consumption, memory, and processing capabilities of nanoelectronic devices. Heusler alloys are potential candidates for application in spintronics due to their room temperature (RT) half-metallicity, high Curie temperature, low lattice mismatch with most substrates, and strong control on electronic density of states at Fermi level. In this work, we investigate the effect of substitutional doping and disorder on the half-metallicity, phase stability, and magnetism of Heusler alloys using density functional theory methods. Our study shows that electronic and magnetic properties of half/full-Heusler alloys can be tuned by changing electron-count through controlled variation of chemical compositions of alloying elements. We provide a detailed discussion on the effect of substitutional doping and disorder on the tunability of half-metallic nature of Co 2 MnX and NiMnX based Heusler alloys, where X represents group 13-16 and period 3-6 elements of the periodic table. Based on the idea of electron count and disorder, we predicted a possible existence of thermodynamically stable half-metallic multicomponent bismuthides, for example, (CuNi 3 )Mn 4 Bi 4 and (ZnNi 7 )Mn 8 Bi 8 , through substitution doping at Ni site by specific Cu and Zn composition in half-Heusler NiMnBi. We believe that the design guide based on electron-counts presented for half-metals will play a key role in electronic-structure engineering of novel Heusler alloys for spintronic application, which will accelerate the development and synthesis of novel materials.

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Section: Density-functional Theory Methodsmentioning

confidence: 99%

“…ESs are treated as empty sites with no cores and small electronic charge density. Because the contribution of exchange in empty spheres is very small, the vLB-correction is calculated only in the atomic spheres [54][55][56][57][58][59][63][64][65].…”

Section: Density-functional Theory Methodsmentioning

confidence: 99%

Effect of substitutional doping and disorder on the phase stability, magnetism, and half-metallicity of Heusler alloys

Zarkevich,

Singh,

Smirnov

et al. 2021

Preprint

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“…Because of its wide bandgap, h−SiC band structure has been in active study for optoelectronic applications. 35 Unlike the polymorphs of carbon, h−SiC is a polar material. In spite of the fact that both constituents of SiC are Group IV elements, charge is transferred from Si to C due its to higher electronegativity.…”

Section: A Application To 2d Materials: H−bn and H−sicmentioning

confidence: 99%

“…[24][25][26] Based on these arguments, some semiempirical functionals are derived and implemented within DFT formalism as correction to the local density approximation (LDA) exchange. 20,21,[26][27][28][29][30][31][32][33][34] These functionals which incorporate density gradients such that the potential is asymptotically well behaved, 21,[33][34][35][36] are mathematically easy to handle and often produced good results without much computational cost. 27,34,36 Similarly, accurate exact-exchange functionals with variations that approach the form enforced by LDA+vLB have appeared, 37 but not yet explored for solids.…”

Section: Introductionmentioning

confidence: 99%

Simple correction to bandgap problems in IV and III–V semiconductors: an improved, local first-principles density functional theory

Datta

Singh

Chaudhuri³

et al. 2019

J. Phys.: Condens. Matter

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We report results from a fast, efficient and first-principles full-potential N th -order muffin-tin orbital (FP-NMTO) method combined with van Leeuwen-Baerends correction to local density approximation exchange-correlation potential. We show that more complete and compact basis set is critical in improving the electronic and structural properties. We exemplify the self-consistent (non-relativistic) FP-NMTO calculations on group IV and III-V semiconductors. Notably, predicted bandgap, lattice constant, and bulk modulus are in good agreement with experiments (e.g., for Ge we find 0.86 eV, 5.57Å, 75 GPa vs. measured: 0.74 eV, 5.66Å, 77.2 GPa). We also showcase its application to the electronic properties of 2-dimensional h−BN and h−SiC, again finding good agreement with experiments. arXiv:1807.07606v3 [cond-mat.mtrl-sci]

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“…We develop a new functionality by implementing vLB-corrected LDA exchange with van Barth-Hedin correlation within TB-LMTO and FP-NMTO to improve the prediction of band gaps and optical proeprties. [49][50][51][52][53] The LDA+vLB results yield accurate band gaps with the computational speed of LDA, whereas the improved basis set of FP-NMTO further improves the band gap. Choice of a minimal basis set is always tricky, but TB-LMTO 44 and FP-NMTO 45,46 provide that platform.…”

Section: Computational Detailsmentioning

confidence: 99%

Exploring the role of electronic structure on photo-catalytic behavior of carbon-nitride polymorphs

Datta,

Singh,

Jana

et al. 2019

Preprint

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We provide a comprehensive account of structural, electronic, and optical properties of carbonnitride (C 3 N 4 ) polymorphs. We employ density-functional theory with two different basis sets for better predictions of structural and electronic band-gap properties: (a) a localized tight-binding basis with an improved semi-empirical exchange functional for more rapid and robust predictions; and (b) a plane-wave basis using a hybrid functional for validation. The predicted lattice constants, bulk moduli, and band gaps are in good agreement with existing experiments and theory, which verifies our predictions are reliable and basis-set independent. The optimal band gap, HOMO-LUMO position, and optical properties show the suitability of γ-C 3 N 4 in photocatalytic applications, while its work function shows orientation dependence with favorable valence and conduction band edges along the (110) direction. We also explore the effect of pressure on structural stability, optical properties, and photocatalytic behavior of γ-C 3 N 4 . Our study suggest an opportunity to tune properties by introducing defects to further improve photocatalytic performance of nitrides.

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Band-gap tuning and optical response of two-dimensionalSixC1−x: A first-principles real-space study of disordered two-dimensional materials

Cited by 15 publications

References 74 publications

Effect of substitutional doping and disorder on the phase stability, magnetism, and half-metallicity of Heusler alloys

Effect of substitutional doping and disorder on the phase stability, magnetism, and half-metallicity of Heusler alloys

Simple correction to bandgap problems in IV and III–V semiconductors: an improved, local first-principles density functional theory

Exploring the role of electronic structure on photo-catalytic behavior of carbon-nitride polymorphs

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