First-Principles Analysis on Interaction between Dopant (Ga, Sb) and Contamination Metal Atoms in Ge Crystals

2013 ◽  
Vol 205-206 ◽  
pp. 417-421
Author(s):  
Tatsunori Yamato ◽  
Koji Sueoka ◽  
Takahiro Maeta

The lowest energetic configurations of metal impurities in 4throw (Sc - Zn), 5throw (Y - Cd) and 6throw (Hf - Hg) elements in Ge crystals were determined with density functional theory calculations. It was found that the substitutional site is the lowest energetic configuration for most of the calculated metals in Ge. The most stable configurations of dopant (Ga, Sb) - metal complexes in Ge crystals were also investigated. Following results were obtained. (1) For Ga dopant, 1st neighbor T-site is the most stable for metals in group 3 to 7 elements while substitutional site next to Ga atom is the most stable for metals in group 8 to 12 elements. (2) For Sb dopant, substitutional site next to Sb atom is the most stable for all calculated metals. Binding energies of the interstitial metalMiwith the substitutional dopantDswere obtained by the calculated total energies. The calculated results for Ge were compared with those for Si.

2017 ◽  
Vol 8 ◽  
pp. 1742-1748
Author(s):  
Fadil Iyikanat ◽  
Ali Kandemir ◽  
Cihan Bacaksiz ◽  
Hasan Sahin

Using first-principles density functional theory calculations, we investigate adsorption properties and the diffusion mechanism of a Li atom on hydrogenated single-layer α- and β-silicene on a Ag(111) surface. It is found that a Li atom binds strongly on the surfaces of both α- and β-silicene, and it forms an ionic bond through the transfer of charge from the adsorbed atom to the surface. The binding energies of a Li atom on these surfaces are very similar. However, the diffusion barrier of a Li atom on H-α-Si is much higher than that on H-β-Si. The energy surface calculations show that a Li atom does not prefer to bind in the vicinity of the hydrogenated upper-Si atoms. Strong interaction between Li atoms and hydrogenated silicene phases and low diffusion barriers show that α- and β-silicene are promising platforms for Li-storage applications.


2021 ◽  
Vol 9 ◽  
Author(s):  
Hyeong Yong Lim ◽  
Sung O Park ◽  
Su Hwan Kim ◽  
Gwan Yeong Jung ◽  
Sang Kyu Kwak

The oxygen evolution reaction (OER) plays a key role in the determination of overall water-splitting rate. Lowering the high overpotential of the OER of transition metal oxides (TMOs), which are used as conventional OER electrocatalysts, has been the focus of many studies. The OER activity of TMOs can be tuned via the strategic formation of a heterostructure with another TMO substrate. We screened 11 rutile-type TMOs (i.e., MO2; M = V, Cr, Mn, Nb, Ru, Rh, Sn, Ta, Os, Ir, and Pt) on a rutile (110) substrate using density functional theory calculations to determine their OER activities. The conventional volcano approach based on simple binding energies of reaction intermediates was implemented; in addition, the electrochemical-step symmetry index was employed to screen heterostructures for use as electrode materials. The results show that RuO2 and IrO2 are the most promising catalysts among all candidates. The scaling results provide insights into the intrinsic properties of the heterostructure as well as materials that can be used to lower the overpotential of the OER.


Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2568
Author(s):  
Mariusz Krawiec ◽  
Agnieszka Stępniak-Dybala ◽  
Andrzej Bobyk ◽  
Ryszard Zdyb

The adsorption and substitution of transition metal atoms (Fe and Co) on Au-supported planar silicene have been studied by means of first-principles density functional theory calculations. The structural, energetic and magnetic properties have been analyzed. Both dopants favor the same atomic configurations with rather strong binding energies and noticeable charge transfer. The adsorption of Fe and Co atoms do not alter the magnetic properties of Au-supported planar silicene, unless a full layer of adsorbate is completed. In the case of substituted system only Fe is able to produce magnetic ground state. The Fe-doped Au-supported planar silicene is a ferromagnetic structure with local antiferromagnetic ordering. The present study is the very first and promising attempt towards ferromagnetic epitaxial planar silicene and points to the importance of the substrate in structural and magnetic properties of silicene.


2009 ◽  
Vol 08 (01n02) ◽  
pp. 5-8 ◽  
Author(s):  
YONG-HUI ZHANG ◽  
KAI-GE ZHOU ◽  
KE-FENG XIE ◽  
CAI-HONG LIU ◽  
HAO-LI ZHANG ◽  
...  

The adsorption of cytosine on graphene surface is studied using density functional theory with local density approximation. The cytosine is physisorbed onto graphene through π–π interaction, with a binding energy around -0.39 eV. Due to the weak interaction, the electronic properties of graphene show little change upon adsorption. The cytosine/graphene interaction can be strongly enhanced by introducing metal atoms. The binding energies increase to -0.60 and -2.31 eV in the presence of Li and Co atoms, respectively. The transport behavior of an electric sensor based on Co -doped graphene shows a sensitivity one order of magnitude higher than that of a similar device using pristine graphene. This work reveals that the sensitivity of graphene-based bio-sensors could be drastically improved by introducing appropriate metal atoms.


RSC Advances ◽  
2019 ◽  
Vol 9 (34) ◽  
pp. 19418-19428
Author(s):  
Yusheng Wang ◽  
Xiaoyan Song ◽  
Nahong Song ◽  
Tianjie Zhang ◽  
Xiaohui Yang ◽  
...  

Using density functional theory calculations, the structural, electronic and magnetic properties of a black phosphorene/Tl2S heterostructure (BP/Tl2S) and the BP/Tl2S intercalated with transition metal atoms (TMs) have been detailed investigated.


2010 ◽  
Vol 21 (12) ◽  
pp. 1469-1477 ◽  
Author(s):  
M. SAMAH ◽  
B. BOUGHIDEN

Structures, binding energies, magnetic and electronic properties endohedrally doped C 20 fullerenes by metallic atoms ( Fe , Co , Ti and V ) have been obtained by pseudopotential density functional theory. All M @ C 20, except Co @ C 20, are more stable than the undoped C 20 cage. The magnetic moment values are 1 and 2μB. These values and semiconductor behavior give to these compounds interesting feature in several technological applications. Titanium doped C 20 has a same magnetic moment than the isolated Ti atom. Hybridization process in the Co doped C 20 fullerene is most strong than in other doped cages. Electrical and magnetic dipoles calculated in the iron doped C 20 are very strong compared with other clusters.


2016 ◽  
Vol 4 (29) ◽  
pp. 11498-11506 ◽  
Author(s):  
Taehun Lee ◽  
Yonghyuk Lee ◽  
Woosun Jang ◽  
Aloysius Soon

Using first-principles density-functional theory calculations, we investigate the advantage of using h-WO3 (and its surfaces) over the larger band gap γ-WO3 phase for the anode in water splitting. We demonstrate that h-WO3 is a good alternative anode material for optimal water splitting efficiencies.


2017 ◽  
Vol 19 (5) ◽  
pp. 3679-3687 ◽  
Author(s):  
Tao Yang ◽  
Masahiro Ehara

Using density functional theory calculations, we discussed the geometric and electronic structures and nucleation of small Co clusters on γ-Al2O3(100) and γ-Al2O3(110) surfaces.


Author(s):  
N. K. Das ◽  
K. Rigby ◽  
N. H. de Leeuw

Density functional theory calculations have been used to study the incorporation of helium in perfect and defect-containing palladium tritides, where we have calculated the energetics of incorporation and the migration behaviour. Helium atoms preferably occupy the octahedral interstitial and substitutional sites in the perfect and Pd vacancy-containing tritides, respectively. The energetics reveal that helium clusters can form in the lattice, which displace the Pd metal atoms. The defective lattice shows less expansion compared with the perfect lattice, which can accommodate the helium less easily. The path from octahedral–tetrahedral–octahedral sites is the lowest energy pathway for helium diffusion, and the energetics indicate that the helium generated from tritium decay can accumulate in or near the octahedral sites. Density of states analyses shows the hybridization between palladium d and tritium s orbitals and repulsion between palladium d and helium s orbitals, which can distort the lattice as a result of generating localized stress.


Sign in / Sign up

Export Citation Format

Share Document