Electronic-structure and thermodynamic properties of ZnS1−Se  ternary alloys from the first-principles calculations

Long, Debing; Li, Mingkai; Meng, Dongxue; He, Yunbin

doi:10.1016/j.commatsci.2018.03.046

Cited by 17 publications

(8 citation statements)

References 84 publications

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“…This value is in very good agreement with previously reported theoretical values, for example, with the value of 0.46 eV reported in Ref. [22] by using a ∆-Sol correction to DFT in GGA. A good agreement is also observed with respect to reported experimental values, which are in the range of 0.35 -0.68 eV [7,39,55,56].…”

Section: E Electronic Structure and Band Gapsupporting

confidence: 93%

“…Although this problem in ZnSe x S 1−x has already been addressed in previous theoretical works [7,[21][22][23], we provide here a detailed and systematic analysis that takes advantage of the large computational capabilities offered by modern supercomputers. In this way, we are able to understand the importance of long range correlation in the stabilization of the bowing parameter, as well as to elucidate the different mechanisms contributing to the changes of the band gap.…”

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confidence: 95%

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Structural and electronic properties of the random alloy ZnSe$_x$S$_{1-x}$

Sarkar,

Eriksson,

Sarma

et al. 2022

Preprint

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In this article we employ density functional theory in the generalized gradient approximation to investigate the structural and electronic properties of the solid solution alloy ZnSe x S 1−x in the wurtzite structure. We analyzed the character of the bond lengths and angles at the atomic scale, using a supercell approach that does not impose any constraint on the crystal potential. We show that the bond lengths of pristine ZnS and ZnSe compounds are almost preserved between nearest neighbors, which is different from what would be anticipated if Vegard's law were valid at the atomic level. We also show that bond lengths start behaving in accordance to Vegard's law from the third shell of nearest neighbors onward, which in turn determines the average lattice parameters of the alloys determined by diffraction experiments. Fundamental building blocks around the anions are identified and are shown to be non-rigid but still volume preserving. Finally, the geometrical analysis is connected to the trend exhibited by the electronic structure, and in particular by the band gap. The latter is found to exhibit a small deviation from the linearity with respect to the Se concentration, in accordance to available experimental data. By assuming a quadratic dependence, we can extract a bowing parameter and analyze various contributions to it with various calculations under selected constraints. The structural deformation in response to the doping process is shown to be the driving force behind the deviation from linearity. The difference in stiffness between ZnS and ZnSe is showed to play a key role in the asymmetric behavior of the bowing parameter observed in the S-rich and Se-rich regions.

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Section: E Electronic Structure and Band Gapsupporting

confidence: 93%

mentioning

confidence: 95%

Structural and electronic properties of the random alloy ZnSe$_x$S$_{1-x}$

Sarkar,

Eriksson,

Sarma

et al. 2022

Preprint

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“…As observed in catalysts containing more than one kind of transition metal, a large number of literature results have demonstrated that there is always an electronic effect between the metal components. ,− In other words, the electronic charge distributions of each metal in bimetallic or trimetallic catalysts differ from those when the metal is presented in the catalysts alone. To study the electronic effect in the PdNi(111)-A catalyst, we firstly investigated the charge distribution and the Mülliken charges.…”

Section: Resultsmentioning

confidence: 99%

Role of Ni in Bimetallic PdNi Catalysts for Ethanol Oxidation Reaction

Miao

Zhang

et al. 2018

J. Phys. Chem. C

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Bimetallic PdNi catalysts have garnered great interest in the study of ethanol oxidation reactions (EORs), though mechanistic insights into their catalytic performances are lacking, which hinders further improvement and rational design of the next generation of PdNi catalysts. As such, density functional theory (DFT) calculations were performed for six key elementary reactions using four model catalysts, one with pure Pd and three for PdNi. DFT results indicate that the reduced catalytic activities observed experimentally when Ni atoms were placed under Pd layers are the result of an increase in the reaction barrier for CH3COOH formation. Further analysis illustrated that this is largely owing to the charge transfer from the Ni to the Pd atoms. On the other hand, the enhanced activities of the PdNi catalysts with respect to pure Pd catalysts in EORs when Ni atoms are exposed at the catalyst surfaces are due to the lowering of the reaction barrier toward C–C bond cleavage and increasing of that toward C–O bond coupling. Therefore, surface Ni atoms are responsible for the superior activity of the PdNi catalysts in EORs. Further analysis of DFT results suggests that the reaction barriers of the C–C bond cleavage and the C–O bond coupling approach similar values when the composition of surface Ni atoms in a PdNi catalyst reaches about 44%. To achieve a complete EOR, the estimated surface Ni atoms should be as high as 77%. However, stability may become a concern for catalysts with such a high exposure of Ni atoms at the catalyst surface.

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“…The calculated value of the optimized bond length between Zn and S was 2.23 Å, which was consistent with previous experiments. 35,36 And then the Paper PCCP electronic energy band structures of monolayer GaSe and monolayer ZnS were calculated as in Fig. 1(b) and 2(b), respectively.…”

Section: Structural and Electronic Propertiesmentioning

confidence: 99%