scholarly journals Replacement of Cobalt in Lithium-Rich Layered Oxides by n-Doping: A DFT Study

2021 ◽  
Vol 11 (22) ◽  
pp. 10545
Author(s):  
Mariarosaria Tuccillo ◽  
Lorenzo Mei ◽  
Oriele Palumbo ◽  
Ana Belén Muñoz-García ◽  
Michele Pavone ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Structural Integrity ◽  
Density Functional Theory Calculations ◽  
Random Structure ◽  
Layered Oxides ◽  
Cobalt Removal ◽  
Jahn Teller ◽  
N Doping ◽  
The Impact

The replacement of cobalt in the lattice of lithium-rich layered oxides (LRLO) is mandatory to improve their environmental benignity and reduce costs. In this study, we analyze the impact of the cobalt removal from the trigonal LRLO lattice on the structural, thermodynamic, and electronic properties of this material through density functional theory calculations. To mimic disorder in the transition metal layers, we exploited the special quasi-random structure approach on selected supercells. The cobalt removal was modeled by the simultaneous substitution with Mn/Ni, thus leading to a p-doping in the lattice. Our results show that cobalt removal induces (a) larger cell volumes, originating from expanded distances among stacked planes; (b) a parallel increase of the layer buckling; (c) an increase of the electronic disorder and of the concentration of Jahn–Teller defects; and (d) an increase of the thermodynamic stability of the phase. Overall p-doping appears as a balanced strategy to remove cobalt from LRLO without massively deteriorating the structural integrity and the electronic properties of LRLO.

scholarly journals Defect Processes in Halogen Doped SnO2

2021 ◽  
Vol 11 (2) ◽  
pp. 551
Author(s):  
Petros-Panagis Filippatos ◽  
Nikolaos Kelaidis ◽  
Maria Vasilopoulou ◽  
Dimitris Davazoglou ◽  
Alexander Chroneos
Keyword(s):  
Electronic Properties ◽  
Tin Oxide ◽  
Density Functional ◽  
Structural Changes ◽  
High Dielectric Constant ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Optical And Electronic Properties ◽  
High Dielectric ◽  
Gap States

In the present study, we performed density functional theory calculations (DFT) to investigate structural changes and their impact on the electronic properties in halogen (F, Cl, Br, and I) doped tin oxide (SnO2). We performed calculations for atoms intercalated either at interstitial or substitutional positions and then calculated the electronic structure and the optical properties of the doped SnO2. In all cases, a reduction in the bandgap value was evident, while gap states were also formed. Furthermore, when we insert these dopants in interstitial and substitutional positions, they all constitute a single acceptor and donor, respectively. This can also be seen in the density of states through the formation of gap states just above the valence band or below the conduction band, respectively. These gap states may contribute to significant changes in the optical and electronic properties of SnO2, thus affecting the metal oxide’s suitability for photovoltaics and photocatalytic devices. In particular, we found that iodine (I) doping of SnO2 induces a high dielectric constant while also reducing the oxide’s bandgap, making it more efficient for light-harvesting applications.

Ab Initio Calculation of Mechanical Properties of Stacking Fault in 3C-SiC: Effect of Stress and Doping

2012 ◽  
Vol 717-720 ◽  
pp. 415-418
Author(s):  
Yoshitaka Umeno ◽  
Kuniaki Yagi ◽  
Hiroyuki Nagasawa
Keyword(s):  
Mechanical Properties ◽  
Ab Initio ◽  
Density Functional ◽  
Stacking Faults ◽  
Single Layer ◽  
Local Strain ◽  
Density Functional Theory Calculations ◽  
Stacking Fault ◽  
Functional Theory ◽  
N Doping

We carry out ab initio density functional theory calculations to investigate the fundamental mechanical properties of stacking faults in 3C-SiC, including the effect of stress and doping atoms (substitution of C by N or Si). Stress induced by stacking fault (SF) formation is quantitatively evaluated. Extrinsic SFs containing double and triple SiC layers are found to be slightly more stable than the single-layer extrinsic SF, supporting experimental observation. Effect of tensile or compressive stress on SF energies is found to be marginal. Neglecting the effect of local strain induced by doping, N doping around an SF obviously increase the SF formation energy, while SFs seem to be easily formed in Si-rich SiC.

Interfacial defect engineering and Photocatalysis Properties of hBN/MX2(M = Mo, W, and X = S, Se) Heterostructures

2021 ◽  
Author(s):  
Zhihai Sun ◽  
Jiaxi Liu ◽  
Ying Zhang ◽  
Ziyuan Li ◽  
Leyu Peng ◽  
...  
Keyword(s):  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Band Alignment ◽  
Type I ◽  
Defect Engineering ◽  
Wide Range ◽  
Interfacial Defects ◽  
Significant Research ◽  
P Type ◽  
The Impact

Abstract Van der Waals (VDW) heterostructures have attracted significant research interest due to their tunable interfacial properties and potential in a wide range of applications such as electronics, optoelectronic, and heterocatalysis. In this work, the impact of interfacial defects on the electronic structures and photocatalytic properties of hBN/MX2(M = Mo, W, and X = S, Se) are studied using density functional theory calculations. The results reveal that the band alignment of hBN/MX2 can be adjusted by introducing vacancies and atomic doping. The type-I band alignment of the host structure was maintained in the heterostructure with n-type doping in the hBN sublayer. Interestingly, the band alignment changed to the type-II heterostructrue as VB defect and p-type doping was introduced in the hBN sublayer. This could be profitable for the separation of photo-generated electron−hole pairs at the interfaces and is highly desired for heterostructure photocatalysis. In addition, two Z-type heterostructures including hBN(BeB)/MoS2, hBN(BeB)/MoSe2, and hBN(VN)/MoSe2 were achieved, showing reducing band gap and ideal redox potential for water splitting. Our results reveal the possibility of engineering the interfacial and photocatalysis properties of hBN/MX2 heterostructures via interfacial defects.

scholarly journals Oxygen Vacancy Induced Magnetism in Anti-Perovskite Topological Dirac Semimetal Ba3SnO

2021 ◽  
Author(s):  
Javaria Batool ◽  
Syed Muhammad Alay-e-Abbas ◽  
Gustav Johansson ◽  
Waqas Zulfiqar ◽  
Muhammad Arsam Danish ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Oxygen Vacancy ◽  
Electronic Properties ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Vacancy Defect ◽  
Functional Theory ◽  
Dirac Semimetal

The thermodynamic, structural, magnetic and electronic properties of pristine and intrinsic vacancy defect containing topological Dirac semimetal Ba3SnO are studied using first-principles density functional theory calculations. The thermodynamic stability of...

scholarly journals An Experimental and Theoretical Study on the Effect of Silver Nanoparticles Concentration on the Structural, Morphological, Optical, and Electronic Properties of TiO2 Nanocrystals

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1488
Author(s):  
Faheem Ahmed ◽  
Mohammed Benali Kanoun ◽  
Chawki Awada ◽  
Christian Jonin ◽  
Pierre-Francois Brevet
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Anatase Phase ◽  
Density Functional Theory Calculations ◽  
Tio2 Nanocrystals ◽  
Uniform Size ◽  
Chemical Route ◽  
Structural And Electronic Properties ◽  
Nanoparticles Concentration ◽  
Gap States

In this work, pure and silver (Ag)-loaded TiO2 nanocrystals (NCs) with various concentrations of Ag were prepared by soft chemical route and the effect of Ag nanoparticles (NPs) on the functional properties of TiO2 was studied. X-ray diffraction (XRD) and Raman studies confirmed that the synthesized product had single-phase nature and high crystalline quality. The crystallite size was decreased from 18.3 nm to 13.9 nm with the increasing in concentration of Ag in TiO2 NCs. FESEM micrographs showed that the pure and AgNPs-loaded TiO2 have spherical morphology and uniform size distribution with the size ranging from 20 to 10 nm. Raman spectroscopy performed on pure and AgNPs-loaded TiO2 confirms the presence of anatase phase and AgNPs. Optical properties show the characteristics peaks of TiO2 and the shifting of the peaks position was observed by changing the concentration of Ag. The tuning of bandgap was found to be observed with the increase in Ag, which could be ascribed to the synergistic effect between silver and TiO2 NCs. Density functional theory calculations are carried out for different Ag series of doped TiO2 lattices to simulate the structural and electronic properties. The analysis of the electronic structures show that Ag loading induces new localized gap states around the Fermi level. Moreover, the introduction of dopant states in the gap region owing to Ag doping can be convenient to shift the absorption edge of pristine TiO2 through visible light.

STRUCTURAL AND ELECTRONIC PROPERTIES OF (CnLi)+ CLUSTER IONS

2005 ◽  
Vol 16 (02) ◽  
pp. 271-280
Author(s):  
EFE YAZGAN ◽  
ŞAKIR ERKOÇ
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Vibrational Frequencies ◽  
Cluster Ions ◽  
Functional Theory ◽  
B3lyp Level ◽  
Structural And Electronic Properties

The structural and electronic properties of ( C n Li )+ cluster ions with n =1–6 and n =20 have been investigated by performing density functional theory calculations at B3LYP level. The vibrational frequencies of the clusters are also calculated.

Tunable electronic properties of the dynamically stable layered mineral Pt2HgSe3 (Jacutingaite)

2020 ◽  
Vol 22 (42) ◽  
pp. 24471-24479 ◽  
Author(s):  
Asadollah Bafekry ◽  
Catherine Stampfl ◽  
Chuong Nguyen ◽  
Mitra Ghergherehchi ◽  
Bohayra Mortazavi
Keyword(s):  
Density Functional Theory ◽  
Electric Field ◽  
Electronic Properties ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Biaxial Strain ◽  
Functional Theory ◽  
Structural And Electronic Properties ◽  
Out Of Plane ◽  
Strain Layer

Density functional theory calculations are performed in order to study the structural and electronic properties of monolayer Pt2HgSe3. Effects of uniaxial and biaxial strain, layer thickness, electric field and out-of-plane pressure on the electronic properties are systematically investigated.

Exceptional mechano-electronic properties in the HfN2 monolayer: a promising candidate in low-power flexible electronics, memory devices and photocatalysis

2020 ◽  
Vol 22 (37) ◽  
pp. 21275-21287 ◽  
Author(s):  
Manish Kumar Mohanta ◽  
I. S. Fathima ◽  
Abir De Sarkar
Keyword(s):  
Density Functional Theory ◽  
Low Power ◽  
Electronic Properties ◽  
Electric Fields ◽  
Flexible Electronics ◽  
Density Functional ◽  
External Perturbation ◽  
Density Functional Theory Calculations ◽  
Promising Candidate ◽  
Functional Theory

The response of the electronic properties of the HfN2 monolayer to external perturbation such as strain and electric fields has been investigated using density functional theory calculations for its device-based applications and photocatalysis.

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