The electronic structure of graphene tuned by hexagonal boron nitrogen layers: Semimetal–semiconductor transition

2016 ◽  
Vol 30 (13) ◽  
pp. 1650191 ◽  
Author(s):  
Ming-Yang Liu ◽  
Qing-Yuan Chen ◽  
Tai Ma ◽  
Yao He ◽  
Chao Cao

The electronic structure of graphene and hexagonal boron nitrogen (G/h-BN) systems have been carefully investigated using the pseudo-potential plane-wave within density functional theory (DFT) framework. We find that the stacking geometries and interlayer distances significantly affect the electronic structure of G/h-BN systems. By studying four stacking geometries, we conclude that the monolayer G/h-BN systems should possess metallic electronic properties. The monolayer G/h-BN systems can be transited from metallicity to semiconductor by increasing h-BN layers. It reveals that the alteration of interlayer distances 2.50–3.50 Å can obtain the metal–semiconductor–semimetal variation and a tunable band gap for G/h-BN composite systems. The band dispersion along [Formula: see text]–[Formula: see text] direction is analogous to the band of rhombohedral graphite when the G/h-BN systems are semiconducting.

2016 ◽  
Vol 30 (20) ◽  
pp. 1650220 ◽  
Author(s):  
Ke Jing Li ◽  
Qing Yi Shao ◽  
Juan Zhang ◽  
Xin Hua Yao

Using density functional theory (DFT), we have investigated the stability and electronic structure of lithium (Li) adsorbed in triplet form of (5.0) carbon nanotubes (CNTs) and (5.0) boron nitrogen nanotubes (BNNTs). We have mainly found that three (5.0) tubes are covalently connected. The triplet form is an energetically stable semiconductor. Li atom can be chemically adsorbed in the triplet form of nanotubes (NTs). Meanwhile, upon the adsorption of Li, the triplet form convert into metal. Hence, the triplet form can improve reactivity and sensitivity of NTs to Li significantly.


2020 ◽  
pp. 2150007
Author(s):  
XIAOHUA YU ◽  
HUIXIA SUN ◽  
GUIRONG SHAO

Using plane-wave ultrasoft pseudopotential method based on first-principles density functional theory (DFT), the adsorption of Cs atom on As-rich GaAs(001)[Formula: see text]([Formula: see text]) reconstruction phase and Ga-rich GaAs(001)([Formula: see text]) reconstruction phase are investigated. The adsorption energy, work function, dipole moment, ionicity, band structure and density of state (DOS) of Cs adsorbed GaAs [Formula: see text]([Formula: see text]) and ([Formula: see text]) models are calculated. The stability and electronic structure of Cs adsorbed GaAs [Formula: see text]([Formula: see text]) and ([Formula: see text]) models are compared. Result shows that [Formula: see text]([Formula: see text]) phase is stable than the ([Formula: see text]) phase and after that Cs adsorption [Formula: see text]([Formula: see text]) phase is more beneficial for photoemission.


2011 ◽  
Vol 1295 ◽  
Author(s):  
Amanda C. Stott ◽  
Phillip B. Abel ◽  
Christopher DellaCorte ◽  
Stephen V. Pepper ◽  
David A. Dixon

ABSTRACTPlane wave ab initio density functional theory (DFT) calculations of the B2 NiTi (100), (110), and (111) surfaces, the B2 and B19´ phases of NiTi, and the supercell structures of NiTi, Ni4Ti3 and Ni3Ti are reported. Electronic energies from the electronic structure calculations are used to assess relative stability of the different surface and supercell geometries.


2019 ◽  
Vol 21 (44) ◽  
pp. 24478-24488 ◽  
Author(s):  
Martin Gleditzsch ◽  
Marc Jäger ◽  
Lukáš F. Pašteka ◽  
Armin Shayeghi ◽  
Rolf Schäfer

In depth analysis of doping effects on the geometric and electronic structure of tin clusters via electric beam deflection, numerical trajectory simulations and density functional theory.


2020 ◽  
Vol 3 (1) ◽  
pp. 20
Author(s):  
Valentina Ferraro ◽  
Marco Bortoluzzi

The influence of copper(I) halides CuX (X = Cl, Br, I) on the electronic structure of N,N′-diisopropylcarbodiimide (DICDI) and N,N′-dicyclohexylcarbodiimide (DCC) was investigated by means of computational DFT (density functional theory) methods. The coordination of the considered carbodiimides occurs by one of the nitrogen atoms, with the formation of linear complexes having a general formula of [CuX(carbodiimide)]. Besides varying the carbon–nitrogen bond lengths, the thermodynamically favourable interaction with Cu(I) reduces the electron density on the carbodiimides and alters the energies of the (NCN)-centred, unoccupied orbitals. A small dependence of these effects on the choice of the halide was observable. The computed Fukui functions suggested negligible interaction of Cu(I) with incoming nucleophiles, and the reactivity of carbodiimides was altered by coordination mainly because of the increased electrophilicity of the {NCN} fragments.


Author(s):  
Huimin Guo ◽  
Xiaolin Ma ◽  
Zhiwen Lei ◽  
Yang Qiu ◽  
Bernhard Dick ◽  
...  

The electronic structure and photophysical properties of a series of N-Methyl and N-Acetyl substituted alloxazine (AZs) were investigated with extensive density functional theory (DFT) and time-dependent density functional theory (TD-DFT)...


2019 ◽  
Vol 150 (1) ◽  
pp. 014101 ◽  
Author(s):  
Daniel A. Rehn ◽  
Yuan Shen ◽  
Marika E. Buchholz ◽  
Madan Dubey ◽  
Raju Namburu ◽  
...  

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