scholarly journals Understanding the non-covalent interaction mediated modulations on the electronic structure of quasi-zero-dimensional graphene nanoflakes

2018 ◽  
Vol 20 (27) ◽  
pp. 18718-18728
Author(s):  
Amrit Sarmah ◽  
Pavel Hobza

Non-covalent interaction mediated controlled perturbations to the electronic properties of nanostructures as an alternative pathway for the non-destructive functionalization of graphene nanostructures.

2015 ◽  
Vol 08 (01) ◽  
pp. 1530001 ◽  
Author(s):  
Biao Wang ◽  
Yunhua Wang ◽  
Yulan Liu

The interplay between the linear elastic deformation up to 20% and the unique electronic properties of graphene nanostructures offers an attractive prospect to manipulate their properties by strain. Here we review the recent progress on the electronic response of graphene to the in-plane strains, including the strain-modulated electronic structure and the strain-modulated spin, valley and superconducting transports. A generalized Hamiltonian for a graphene was constructed subjected to arbitrary in-plane strains. The Hamiltonian is helpful to design and optimize the graphene-based nano-electromechanical systems (NEMS).


2021 ◽  
Vol 9 (36) ◽  
pp. 20653-20663
Author(s):  
Johanna Eichhorn ◽  
Simon P. Lechner ◽  
Chang-Ming Jiang ◽  
Giulia Folchi Heunecke ◽  
Frans Munnik ◽  
...  

The (opto)electronic properties of Ta3N5 photoelectrodes are often dominated by defects, but precise control of these defects provides new insight into the electronic structure, photocarrier transport, and photoelectrochemical function.


1996 ◽  
Vol 442 ◽  
Author(s):  
Harald Overhof

AbstractThe electronic properties of 3d transition metal (TM) defects located on one of the four different tetrahedral positions in 3C SiC are shown to be quite site-dependent. We explain the differences for the 3d TMs on the two substitutional sites within the vacancy model: the difference of the electronic structure between the carbon vacancy VC and the silicon vacancy VSi is responsible for the differences of the 3d TMs. The electronic properties of 3d TMs on the two tetrahedral interstitial sites differ even more: the TMs surrounded tetrahedrally by four Si atoms experience a large crystal field splitting while the tetrahedral C environment does not give rise to a significant crystal field splitting at all. It is only in the latter case that high-spin configurations are predicted.


2003 ◽  
Vol 793 ◽  
Author(s):  
Daniel I Bilc ◽  
S.D. Mahanti ◽  
M.G. Kanatzidis

ABSTRACTComplex quaternary chalcogenides (AgSb)xPbn-2xTen (0<x<n/2) are thought to be narrow band-gap semiconductors which are very good candidates for room and high temperature thermoelectric applications. These systems form in the rock-salt structure similar to the well known two component system PbTe (x=0). In these systems Ag and Sb occupy Pb sites randomly although there is some evidence of short-range order. To gain insights into the electronic structure of these compounds, we have performed electronic structure calculations in AgSbTe2 (x=n/2). These calculations were carried out within ab initio density functional theory (DFT) using full potential linearized augmented plane wave (LAPW) method. The generalized gradient approximation (GGA) was used to treat the exchange and correlation potential. Spinorbit interaction (SOI) was incorporated using a second variational procedure. Since it is difficult to treat disorder in ab initio calculations, we have used several ordered structures for AgSbTe2. All these structures show semimetallic behavior with a pseudogap near the Fermi energy. Te and Sb p orbitals, which are close in energy, hybridize rather strongly indicating a covalent interaction between Te and Sb atoms.


2016 ◽  
Vol 18 (32) ◽  
pp. 22617-22627 ◽  
Author(s):  
S. Livraghi ◽  
N. Barbero ◽  
S. Agnoli ◽  
C. Barolo ◽  
G. Granozzi ◽  
...  

The electronic structure of nitrogen doped tin(iv) oxide (SnO2) materials prepared in the form of nanometric powders has been characterized employing a variety of spectroscopic techniques.


2014 ◽  
Vol 513-517 ◽  
pp. 347-350
Author(s):  
Bo Wei Chen ◽  
Ye Wei Xu ◽  
Lin Zhang

Perylene Bisimides Derivatives (PBIs) are typical semiconductor materials. The electronic structures of PBIs were successfully investigated by density functions theory (DFT). The computational results were in the good accordance with the experimental UV-vis spectra. Additionally, the electronic structure and the variational UV-vis absorption spectra of PBIs were explained.


2002 ◽  
Vol 09 (02) ◽  
pp. 687-691
Author(s):  
L. I. JOHANSSON ◽  
C. VIROJANADARA ◽  
T. BALASUBRAMANIAN

A study of effects induced in the Be 1s core level spectrum and in the surface band structure after Si adsorption on Be(0001) is reported. The changes in the Be 1s spectrum are quite dramatic. The number of resolvable surface components and the magnitude of the shifts do decrease and the relative intensities of the shifted components are drastically different compared to the clean surface. The surface band structure is also strongly affected after Si adsorption and annealing. At [Formula: see text] the surface state is found to move down from 2.8 to 4.1 eV. The band also splits at around 0.5 Å-1 along both the [Formula: see text] and [Formula: see text] directions. At [Formula: see text] and beyond [Formula: see text] only one surface state is observed in the band gap instead of the two for the clean surface. Our findings indicate that a fairly small amount of Si in the outer atomic layers strongly modifies the electronic properties of these layers.


2019 ◽  
Vol 21 (44) ◽  
pp. 24731-24739 ◽  
Author(s):  
Fábio R. Negreiros ◽  
Germán J. Soldano ◽  
Sergio Fuentes ◽  
Trino Zepeda ◽  
Miguel José-Yacamán ◽  
...  

We report a combined experimental/theoretical approach to study the connection of S-vacancies and wrinkling on MoS2 layers, and how this feature produces significant changes in the electronic structure and reactivity of this 2D material.


Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1236 ◽  
Author(s):  
Hong-Jui Huang ◽  
Sonai Seenithurai ◽  
Jeng-Da Chai

At the nanoscale, it has been rather troublesome to properly explore the properties associated with electronic systems exhibiting a radical nature using traditional electronic structure methods. Graphene nanoflakes, which are graphene nanostructures of different shapes and sizes, are typical examples. Recently, TAO-DFT (i.e., thermally-assisted-occupation density functional theory) has been formulated to tackle such challenging problems. As a result, we adopt TAO-DFT to explore the electronic properties associated with diamond-shaped graphene nanoflakes with n = 2–15 benzenoid rings fused together at each side, designated as n-pyrenes (as they could be expanded from pyrene). For all the n values considered, n-pyrenes are ground-state singlets. With increasing the size of n-pyrene, the singlet-triplet energy gap, vertical ionization potential, and fundamental gap monotonically decrease, while the vertical electron affinity and symmetrized von Neumann entropy (which is a quantitative measure of radical nature) monotonically increase. When n increases, there is a smooth transition from the nonradical character of the smaller n-pyrenes to the increasing polyradical nature of the larger n-pyrenes. Furthermore, the latter is shown to be related to the increasing concentration of active orbitals on the zigzag edges of the larger n-pyrenes.


2019 ◽  
Vol 21 (40) ◽  
pp. 22647-22653 ◽  
Author(s):  
Georgy V. Pushkarev ◽  
Vladimir G. Mazurenko ◽  
Vladimir V. Mazurenko ◽  
Danil W. Boukhvalov

First principles calculations of the magnetic and electronic properties of VSe2 describing the transition between two structural phases (H,T) were performed.


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