Comparative Study of Carbon and BN Nanographenes: Ground Electronic States and Energy Gap Engineering

2008 ◽  
Vol 112 (33) ◽  
pp. 12677-12682 ◽  
Author(s):  
Xingfa Gao ◽  
Zhen Zhou ◽  
Yuliang Zhao ◽  
Shigeru Nagase ◽  
S. B. Zhang ◽  
...  
Keyword(s):  
Comparative Study ◽  
Energy Gap ◽  
Electronic States

The Energy Band Structure of Polyacene with Soliton Excitation

1997 ◽  
Vol 11 (11) ◽  
pp. 477-483 ◽  
Author(s):  
Z. J. Li ◽  
H. B. Xu ◽  
K. L. Yao
Keyword(s):  
Band Structure ◽  
Charge Density ◽  
Energy Band ◽  
Energy Gap ◽  
Electronic States ◽  
Energy Band Structure ◽  
Energy Spectra ◽  
Energy Band Gap ◽  
The One ◽  
Soliton Excitation

Starting from the extensional Su–Schrieffer–Heeger model taking into account the effects of interchain coupling, we have studied the energy spectra and electronic states of soliton excitation in polyacene. The dimerized displacement u0 is found to be similar to the case of trans-polyacetylene, and equals to 0.04 Å. The energy-band gap is 0.38 eV, in agreement with the results derived by other authors. Two new bound electronic states have been found in the conduction band and in the valence band, which is different from the one of trans-polyacetylene. There exists two degenerate soliton states in the center of energy gap. Furthermore, the distribution of charge density and spin density have been discussed in detail.

Tailoring plasmon excitations in α − T3 armchair nanoribbons

2021 ◽  
Author(s):  
Andrii Iurov ◽  
Liubov Zhemchuzhna ◽  
Godfrey Gumbs ◽  
Danhong Huang ◽  
Paula Fekete ◽  
...  
Keyword(s):  
Energy Gap ◽  
Graphene Nanoribbons ◽  
Electronic States ◽  
Landau Damping ◽  
Next Generation ◽  
Polarization Function ◽  
Edge Termination

Abstract We have calculated and investigated the electronic states, dynamical polarization function and the plasmon excitations for α − T3 nanoribbons with armchair-edge termination. The obtained plasmon dispersions are found to depend significantly on the number of atomic rows across the ribbon and the energy gap which is also determined by the nanoribbon geometry. The bandgap appears to have the strongest effect on both the plasmon dispersions and their Landau damping. We have determined the conditions when relative hopping parameter α of an α − T3 lattice has a strong effect on the plasmons which makes our material distinguished from graphene nanoribbons. Our results for the electronic and collective properties of α − T3 nanoribbons are expected to find numerous applications in the development of the next-generation electronic, nano-optical and plasmonic devices.

Theoretical investigations of the electronic states of NaXe: A comparative study

2012 ◽  
Vol 137 (22) ◽  
pp. 224310 ◽  
Author(s):  
F. Ben Salem ◽  
M. Ben El Hadj Rhouma ◽  
F. Spiegelman ◽  
J.-M. Mestdagh ◽  
M. Hochlaf
Keyword(s):  
Comparative Study ◽  
Electronic States ◽  
Theoretical Investigations

A comparative study of suppression of the energy gap with La substitution in the Kondo insulators: CeNiSn and CeRhSb

1996 ◽  
Vol 161 ◽  
pp. 157-168 ◽  
Author(s):  
D.T. Adroja ◽  
B.D. Rainford ◽  
A.J. Neville ◽  
P. Mandal ◽  
A.G.M. Jansen
Keyword(s):  
Comparative Study ◽  
Energy Gap ◽  
Kondo Insulators ◽  
La Substitution

The Role of Hydrogen in Semi-Insulating Inp

1998 ◽  
Vol 513 ◽  
Author(s):  
Yujie Han ◽  
Xunlang Liu ◽  
Jinghua Jiao ◽  
Jiajun Qian ◽  
Yonghai Chen ◽  
...  
Keyword(s):  
Energy Level ◽  
Energy Gap ◽  
Electronic States ◽  
Extended Defects ◽  
Acceptor Level ◽  
Hydrogen Atoms ◽  
Deep Acceptor ◽  
Deep Acceptor Level ◽  
Deep Donor

ABSTRACTComplexes of vacancy at indium site with one to four hydrogen atoms and isolated hydrogen or hydrogen dimer and other infrared absorption lines, tentatively be assigned to hydrogen related defects were investigated by FTIR. Hydrogen can passivate imperfections, thereby eliminating detrimental electronic states from the energy bandgap.Incorporated hydrogen can introduce extended defects and generate electrically-active defects. Hydrogen also can acts as an actuator for creating of antistructure defects. Isolated hydrogen related defects(e.g. H12+) may play an important role in the conversion of the annealed wafers from semiconducting to the semi-insulating behavior. H2+ may be a deep donor, whose energy level is very near the iron deep acceptor level in the energy gap.

A Comparative Study of Hydrogenated Amorphous Silicon Films Prepared by RF Sputtering in He/H2, Ar/H2 and Xe/H2 Mixtures

1986 ◽  
Vol 70 ◽  
Author(s):  
Mark L. Albers ◽  
H. R. Shanks ◽  
J. Shinar
Keyword(s):  
Comparative Study ◽  
Energy Gap ◽  
Rf Sputtering ◽  
Dangling Bond ◽  
Rf Power ◽  
Optical Energy Gap ◽  
Sputtered Films ◽  
Optical Gap ◽  
Hydrogenated Amorphous ◽  
Spin Densities

ABSTRACTPreliminary results of a comparative study of some optical and ESR properties of aSi:H films prepared by rf sputtering on a cold substrate in 10 mtorr of either He, Ar, or Xe and 0.5 mtorr H2 are presented. In all cases the concentration of Si-H and Si-H2 bonds, the optical gap and the dangling bond spin density all generally increase as the rf power is decreased from 3.3 to 0.27 W/cm2. However, whereas the optical energy gap of He/H2 sputtered films ranges from 1.26 eV to 2.13 eV, the gap of Ar/H2 and Xe/H2 films sputtered under these conditions only changes from 1.54 to 1.94 and 1.41 to 1.71 eV, respectively. The dangling bond spin densities are lowest (~1017 cm-3) in the Ar/H2 sputtered films at high rf power and highest (~5x1018 cm-3) in Xe/H2 sputtered films at low power.

scholarly journals Observation of Graphite-Like and Diamond-Like Nanostructures in the Raman Spectra of Natural and Synthesized MoS2 Crystals with Small Carbon Additives

2020 ◽  
Vol 21 (4) ◽  
pp. 598-620
Author(s):  
N.E. Kornienko ◽  
A.P. Naumenko ◽  
L.M. Kulikov
Keyword(s):  
Laser Radiation ◽  
Numerical Analysis ◽  
Comparative Study ◽  
Raman Spectra ◽  
Electronic States ◽  
Carbon Structures ◽  
Carbon Additives ◽  
Spectral Components ◽  
Graphite Structure ◽  
Resonant Radiation

A comparative study of Raman spectra excited by laser radiation λL = 632.8 nm and 488 nm of natural crystals of 2H-MoS2 and nanocrystallites MoS2 (C) containing 0.5 and 1.0 wt.% Carbon additives. A detailed numerical analysis of the shape of observed D and G bands was performed. The complication of the spectra of graphite-like and diamond-like structures with the appearance of additional spectral components at 1440-1500 cm-1 and 1230-1270 cm-1 as a result of doubling the size of the corresponding elementary quasi-cells are analyzed. It is shown that the frequencies of  D-bands of diamond-like nanostructures 1297 ÷ 1302 cm-1 don’t depend on λL in contrast to the change in the frequencies of the G (k)-bands. A significant effect of 632.8 nm resonant radiation on the electronic states and properties of MoS2 (C) NC was established. The strengthening of the D bands of the diamond-like structure and the ordering of the graphite structure with increasing carbon content in MoS2 (C) nanocrystals have been established. The change of spectral positions of D, G, and G (k) bands at strengthening the degree of disordering of a diamond- and graphite-like structures is considered. The influence of laser radiation on carbon structures is discussed.

scholarly journals Novel Empirical Correlation Between the Optical Refractive Index and Energy Bandgap in Semiconductors: Comparative Study

2021 ◽  
Author(s):  
Hosam Mohamed Gomaa ◽  
I.S. Yahia ◽  
H.Y. Zahran
Keyword(s):  
Experimental Data ◽  
Refractive Index ◽  
Comparative Study ◽  
Optical Band Gap ◽  
Energy Gap ◽  
Theoretical Studies ◽  
Oxide Glasses ◽  
High Agreement ◽  
Different Types ◽  
Number Of Publications

Abstract This work is an attempt to review some of the most famous and important studies to correlate the optical-linear refractive index of a substance to its energy band-gap.The refractive index of different types of materials, like semiconductors, insulators, oxides, thin-films, and oxide glasses, has been reported in a large number of publications in attempts to the estimation of how it can be correlated to the optical band-gap. The present work can be considered as a comparative study between the most successful relations in correlating the refractive index to the energy gap. The careful reviewing of the previous studies to correlate the optical refractive index and energy gap led to concluded that Reddy and Ahmmed approximation was selected to develop a new realized form that can give a good fit to the experimental data and, hence, be used directly as an accurate formula in the theoretical studies. The obtained formula correlates the optical refractive index to the energy gap and the oxygen atom's electronegativity. Such relation has been used to calculate the refractive indices for more than 96 materials (elements/compounds) with a high agreement with the experimental data.

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