scholarly journals Effects of Vacancy and Hydrogen on the Growth and Morphology of N-Type Phosphorus-Doped Diamond Surfaces

2021 ◽  
Vol 11 (4) ◽  
pp. 1896
Author(s):  
Siyuan Nie ◽  
Wei Shen ◽  
Shengnan Shen ◽  
Hui Li ◽  
Yuanhui Pan ◽  
...  
Keyword(s):  
Density Function ◽  
Formation Energy ◽  
Function Theory ◽  
Density Function Theory ◽  
Structural Deformation ◽  
Diamond Surfaces ◽  
Bond Population ◽  
Phosphorus Doped ◽  
Formation Energies

Phosphorus is regarded as the best substitutional donor for n-type diamonds. However, because of vacancy-related complexes, H-related complexes, and other defects in P-doped diamonds, obtaining n-type diamonds with satisfying properties is challenging. In this report, PV and PVH complexes are studied in detail using density function theory (DFT). The formation energy reveals the possibility of emergency of these complexes when doping a single P atom. Although vacancies have difficulty forming on the surface alone, the presence of P atoms benefits the formation of PV and PVH complexes and significantly increases crystal vacancies, especially in (111) diamond surfaces. Compared to (111) surfaces, PV and PVH complexes more easily form on (001) surfaces. However, the formation energies of these complexes on (001) surfaces are higher than those of doping P atoms. Studying the structural deformation demonstrated that both constraints of the upper and lower C layers and forces caused by structural deformation prevented doping P atoms. By analyzing the bond population around these dopants, it finds that the bond populations of P–C bonds of PVH complexes are larger than those of PV complexes, indicating that the PV complexes are not as stable as the PVH complexes.

Calculation study on complex formation of catechins with β-cyclodextrin using density function theory

2021 ◽  
Author(s):  
Hirohito Ikeda ◽  
Tomonori Ohata ◽  
Miho Yukawa ◽  
Hiroyuki Tsutsumi ◽  
Masao Fujisawa ◽  
...  
Keyword(s):  
Complex Formation ◽  
Density Function ◽  
Function Theory ◽  
Density Function Theory

scholarly journals Synthesis and Characterisation of Copper(II) Complexes with Tridentate NNO Functionalized Ligand: Density Function Theory Study, DNA Binding Mechanism, Optical Properties, and Biological Application

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Madhumita Hazra ◽  
Tanushree Dolai ◽  
Akhil Pandey ◽  
Subrata Kumar Dey ◽  
Animesh Patra
Keyword(s):  
Density Function ◽  
Antimicrobial Agents ◽  
Function Theory ◽  
Free Ligand ◽  
Fluorescence Emission ◽  
Building Blocks ◽  
Density Function Theory ◽  
Calf Thymus Dna ◽  
Spectroscopic Techniques ◽  
Calf Thymus

The photo physical properties of two mononuclear pentacoordinated copper(II) complexes formulated as [Cu(L)(Cl)(H2O)] (1) and [Cu(L)(Br)(H2O)] (2)HL = (1-[(3-methyl-pyridine-2-ylimino)-methyl]-naphthalen-2-ol) were synthesized and characterized by elemental, physicochemical, and spectroscopic methods. The density function theory calculations are used to investigate the electronic structures and the electronic properties of ligand and complex. The interactions of copper(II) complexes towards calf thymus DNA were examined with the help of absorption, viscosity, and fluorescence spectroscopic techniques at pH 7.40. All spectroscopy's result indicates that complexes show good binding activity to calf thymus DNA through groove binding. The optical absorption and fluorescence emission properties of microwires were characterized by fluorescence microscope. From a spectroscopic viewpoint, all compounds strongly emit green light in the solid state. The microscopy investigation suggested that microwires exhibited optical waveguide behaviour which are applicable as fluorescent nanomaterials and can be used as building blocks for miniaturized photonic devices. Antibacterial study reveals that complexes are better antimicrobial agents than free Schiff base due to bacterial cell penetration by chelation. Moreover, the antioxidant study of the ligand and complexes is evaluated by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical assays, which demonstrate that the complexes are of higher antioxidant activity than free ligand.

Analysis of Ring-Opening Reaction between Bisphenol A and Epichlorohydrin by the Method of Quantum Chemical Calculating

2011 ◽  
Vol 221 ◽  
pp. 180-183 ◽  
Author(s):  
Jian Li ◽  
Xun Zhang Yu ◽  
Kai Zhang
Keyword(s):  
Bisphenol A ◽  
Density Function ◽  
Quantum Chemical ◽  
Ring Opening ◽  
Function Theory ◽  
Dft Method ◽  
Density Function Theory ◽  
Ring Opening Reaction ◽  
Calculation Results ◽  
Opening Process

The ring-opening reaction between bisphenol A and epichlorohydrin was calculated by Gaussian03. The Density Function Theory (DFT) method were employed to study the geometry structures of bisphenol A and epichlorohydrin and the product was obtained on the base of B3LYP/6-31G+ model in this paper. The transitional states (Ts1, Ts2) during the ring-opening process were found by TS method and the energy changing of the system was proved by IRC calculation. Results showed that the energy reduced by 64.37726kJ/mol during the ring-opening process. The product was confirmed to be thermodynamically stable.

exo- and endo-Complexes of Fe(0) with Carbon Allotropic Modifications on the Example of Fullerene С60: a Density Function Theory Study

2021 ◽  
Vol 91 (5) ◽  
pp. 828-834
Author(s):  
K. V. Zaitsev ◽  
A. Yu. Oprunenko ◽  
I. P. Gloriozov ◽  
M. S. Nechaev ◽  
Yu. F. Oprunenko ◽  
...  
Keyword(s):  
Density Function ◽  
Function Theory ◽  
Density Function Theory ◽  
Allotropic Modifications

Calculation of electron structure by density function theory and electrochemical process of surface (100) of FeS2

2007 ◽  
Vol 14 (5) ◽  
pp. 618-622 ◽  
Author(s):  
Quan Li ◽  
Wen-qing Qin ◽  
Wei Sun ◽  
Guan-zhou Qiu
Keyword(s):  
Density Function ◽  
Function Theory ◽  
Electrochemical Process ◽  
Density Function Theory ◽  
Electron Structure

Silylene Reaction with Acetylene: Elucidating the Mechanism by Theoretical Identification of a New Intermediate

2011 ◽  
Vol 36 (4) ◽  
pp. 323-328
Author(s):  
Yiling Bei ◽  
Qingyang Liu
Keyword(s):  
Kinetic Analysis ◽  
Density Function ◽  
Room Temperature ◽  
Function Theory ◽  
Reaction Pathway ◽  
Dft Method ◽  
Density Function Theory

The reaction of silylene with acetylene was observed by the density function theory (DFT) method at the 6 - 311 g (d,p) level. A new reaction pathway has been identified involving the tetra-conjugated: SiH2CH==CHH2Si:. Thermodynamic and kinetic analysis confirms the reaction to be spontaneous at room temperature. The new intermediate proposed in this work offers a resolution of the conundrum of the silylene/acetylene reaction.

Investigation of the half-metallicity, magnetism and spin transport properties of double half-Heusler alloys Mn2CoCrZ2 (Z=P, As)

2021 ◽  
Author(s):  
Cui Zhou ◽  
Ding Haonan ◽  
Yu Feng
Keyword(s):  
Green’S Function ◽  
Transport Properties ◽  
Density Function ◽  
Green's Function ◽  
Spin Transport ◽  
Function Theory ◽  
Heusler Alloys ◽  
Density Function Theory ◽  
Half Metallicity ◽  
Nonequilibrium Green's Function

A new subfamily of Heusler alloys, i.e. double half-Heusler alloys Mn2CoCrZ2 (Z=P, As), are investigated by employing the density function theory combined with the nonequilibrium Green’s function. The calculations on...

Ab initio investigation of ultrasmall silicon nanocrystal doping by phosphorous

2020 ◽  
Vol 34 (30) ◽  
pp. 2050284
Author(s):  
Shermakhmat Makhkamov ◽  
Feruza Umarova ◽  
Asror Normurodov ◽  
Nadimbek Sulaymonov ◽  
Mannab Tashmetov ◽  
...  
Keyword(s):  
Structural Change ◽  
Electronic Properties ◽  
Quantum Confinement ◽  
Function Theory ◽  
Density Function Theory ◽  
Structural Deformation ◽  
Length Scale ◽  
Bulk Silicon ◽  
Quantum Confinement Effects ◽  
Structural And Electronic Properties

The influence of a single phosphorous impurity on structural and electronic properties of spherical, diamond-like, hydrogen-passivated, ultrasmall Si[Formula: see text]H[Formula: see text], Si[Formula: see text]H[Formula: see text], Si[Formula: see text]H[Formula: see text] and Si[Formula: see text]H[Formula: see text] nanocrystals with silicon core diameters of 0.88, 1.03, 1.26 and 1.58 nm was studied by density function theory calculations. In this ultrasmall length scale, the dependence of structural deformation and electronic properties with gradually increasing sizes has not been practically investigated. A detailed analysis of the structural deformation and charge distribution initiated by the presence of the impurity is conducted to understand how structural change occurs within this length scale, where quantum confinement effects become predominant. The Si[Formula: see text]P[Formula: see text]H[Formula: see text] nanocrystal with P[Formula: see text] located in its center is completely deformed. In a larger nanocrystal, the spherical surrounding impurity remains and the P–Si bond lengths increase. In Si[Formula: see text]P[Formula: see text]H[Formula: see text], the first sphere is expanded, energies of phosphorous formation in central and subsurface positions differ insignificantly, and the P atom can be located in both the central and subsurface positions. In all nanoparticles, the charges of central P[Formula: see text] atoms are negative. The width of the bandgap in undoped nanocrystals is much larger than in bulk silicon and depends on their sizes. The phosphorous introduces the splitting level in the bandgap located closer to the conduction band.

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