scholarly journals Electronic structure of complexes of oligomers of 3,4-ethylene-dietoxythiophene with polystyrlesulphonic acid

Surface ◽  
2021 ◽  
Vol 13(28) ◽  
pp. 84-93
Author(s):  
M. I. Terebinska ◽  
O. I. Tkachuk ◽  
A. M. Datsyuk ◽  
O. V. Filonenko ◽  
V. V. Lobanov

By the method of density functional theory (B3LYP, 6-31G **) the electronic structures of poly 3,4-ethylenedioxythiophene containing 12 links in charge states 0, +1, +2, +3 and +4 were calculated. It is shown that the oligomer of 12 units is sufficient to reflect the properties of the conductive polymer. To estimate the probability of electron density movement along the polymer chain, the width of the energy gap between NOMO and LUMO was calculated. It is shown that the molecules of oligomers EDOT and SS do not remain parallel to each other after polymerization, but rather, with increasing chain length, the latter gradually bends around the anionic unit SS; the charge distribution in the EDOT and SS oligomer complexes indicates the presence of two separated polarons at the two ends of the chain, and the asymmetry in the charge distribution also implies the presence of a curved spiral structure of the formed complex.

2021 ◽  
Vol 6 (3) ◽  
pp. 107-115
Author(s):  
Fares A. Yasseen ◽  
Faeq A. Al-Temimei

In the present work, geometries, electronic structures, photovoltaic and optical properties have been carried out on a series of structures formation of phthalocyanine and Titanylphthalocyanine dyes, which are replaced by several subgroup. A density functional theory (DFT) approach together with hybrid function (B3LYP) at SDD basis set was used for the ground state properties in the gas phase. The time-dependent density functional theory (TD-DFT)/ B3LYP was used to investigate the excitation properties of new dyes and analyzed the trends in their optical and redox characteristics. Theoretical principles of HOMO and LUMO energy levels of dyes is requisite in analyzing organic solar cells, thus, HOMO, LUMO levels, open circuit voltage, energy gap, light harvestings efficiency, electron regeneration and electron injection have been calculated and discussed. The outcome of the efficiency, the considered dyes explain absorption energy and wavelength properties that correspond to the solar spectrum requirements. According to results, all the considered materials have a good property and possibility of electron injection procedure from the dyes to conduction band of TiO2, PC60BM or PC60BM. As a result, the molecular changes affect the electronic properties of dye molecules for solar cells. Also, a study of new dyes sensitizers showed that designed materials will be excellent sensitizers. Theoretical designing will prae a way for experimentalists to synthesize the efficient sensitizers for solar cells clearer.


2017 ◽  
Vol 19 (22) ◽  
pp. 14495-14502
Author(s):  
Laxman Tatikondewar ◽  
Anjali Kshirsagar

To investigate energy gap bowing in homogeneously alloyed CdSxSe1−x quantum dots (QDs) and to understand whether it is different from bulk, we perform density functional theory based electronic structure calculations for spherical QDs of different compositions x (0 ≤ x ≤ 1) and of varying sizes (2.2 to 4.6 nm).


2011 ◽  
Vol 295-297 ◽  
pp. 569-573
Author(s):  
Li Wang ◽  
Jian Hong Gong ◽  
Jun Gao

We employ density functional theory to investigate TiAl3/Al interfaces with the orientation of (001) [100]Al//(001)[100]TiAl3 by electronic structures, relaxed atomic geometries and adhesions. The preferable interfacial atomic structure is that wherein Al atoms continue on the natural stacking sequence of bulk TiAl3. Two types of TiAl3 (001) slabs, Ti-centered, all Al atoms, are adopted to compare interfacial energy, interfacial electronic structure. The calculated adhesion energies Wadof the two types of interface are very close, and are quantitatively in agreement with other calculated results of Al on the carbide and nitride, but much lower than the (111)Al[1 0]Al//(0001)TiB2[11 0]TiB2 adhesion energy. We have thoroughly characterized the electronic structure and determined that the metallic Al-3p and Ti-3d bonding constitute the primary interfacial bonding interaction.


2014 ◽  
Vol 1028 ◽  
pp. 7-13
Author(s):  
Guo Jun Kang ◽  
Chao Song ◽  
Xue Feng Ren

A series of silicon (VI) porphyrins compounds with varying meso substitutions Si (TPP)Cl2 (where X=5,10,15,20-tetraphenylporphyrin), Si (TFP)Cl2 (X=5,10,15,20-tetrafluorenylporphyrin), Si (TQP)Cl2(X=5‚10‚15‚20-tetra (2,3,6,7-tetrahydro-1H,5H-benzo [ij] puinolizine) porphyrin),Si (TMP)Cl2(X=5,10,15,20-tetra (N,N-dimethylphenyl) porphyrin) have been investigated using density functional theory (DFT) to assess the influence of ruffled conformation on the electronic structures, frontier molecular orbital, charge carrier transport, electronic spectra. The electronic structures reveal that all these Si porphyrins display visible ruffling distortion, as the dihedral angle Cα2-N2-N4-Cα4 are ca. 30 ̊. And calculations confirm that ruffed distortion result in higher LUMO energies, lower EA values than corresponding planed Zn porphyrins, especial for similar λhole and λelectron values. These calculations suggest that the ruffled conformation bring about better charge injection and transport, which would broaden the application of distorted porphyrin in several different fields.


RSC Advances ◽  
2019 ◽  
Vol 9 (17) ◽  
pp. 9342-9347 ◽  
Author(s):  
Maolin Bo ◽  
Jibiao Li ◽  
Chuang Yao ◽  
Zhongkai Huang ◽  
Lei Li ◽  
...  

The electronic structures of two-dimensional (2D) indium (In) and bismuth (Bi) metal on BN nanosheets are systematically studied using hybrid density functional theory (DFT).


2012 ◽  
Vol 519 ◽  
pp. 174-178
Author(s):  
Tong Wei Li ◽  
La Chen ◽  
Yang Wang ◽  
Jin Cang Zhang

The electronic structures of the titanium-doped cubic perovskite ruthenates BaRu1-xTixO3 with x=0.125, 0.25, 0.375, 0.5, 0.625, 0.75, and 0.875 are investigated using the spin-polarized density functional theory within the pseudopotential plane wave method. It is found that a half-metallic phase appears in the 0.75- and 0.875-doped systems, and the origin of half-metallic property is the decrease of t2g bandwidth of Ru 4d states with the increase in x. In addition, the energy gap of BaRu0.25Ti0.75O3 is as large as 1.7 eV at the Fermi level in the up-spin density of states, which suggests a stable half-metallic phase can be obtained in the present systems.


2016 ◽  
Vol 18 (27) ◽  
pp. 18312-18322 ◽  
Author(s):  
Sumandeep Kaur ◽  
Ashok Kumar ◽  
Sunita Srivastava ◽  
K. Tankeshwar

We report the tailoring of the electronic structures of various structural phases of phosphorene (α-P, β-P, γ-P and δ-P) based homo- and hetero-bilayers through in-plane mechanical strains, vertical pressure and transverse electric field by employing density functional theory.


2020 ◽  
Vol 24 (05n07) ◽  
pp. 894-903
Author(s):  
Dustin E. Nevonen ◽  
Laura S. Ferch ◽  
Victor Y. Chernii ◽  
David E. Herbert ◽  
Johan van Lierop ◽  
...  

The electronic structures of a set of PcFe(azole)2 complexes (azole = imidazole, [Formula: see text]-methylimidazole, pyrazole, isoxazole, thiazole, 1,2,4-triazole, 3-amino-1,2,4,-triazole, and 5-amino-1,2,3,4-tetrazole) were examined by Mössbauer spectroscopy and Density Functional Theory (DFT) calculations. In addition, the geometric distortions in these compounds were elucidated by X-ray crystallography for imidazole, pyrazole, and thiazole-containing compounds. Predicted by DFT calculations, Mössbauer hyperfine parameters for all compounds are in reasonable agreement with experimental results, and the influence of the [Formula: see text]-donor and [Formula: see text]-acceptor properties of the axial azoles on the electronic structure of the PcFe(azole)2 complexes is demonstrated by comparison with the reference PcFePy2 compound.


2015 ◽  
Vol 17 (29) ◽  
pp. 19039-19044 ◽  
Author(s):  
Zeyuan Ni ◽  
Emi Minamitani ◽  
Yasunobu Ando ◽  
Satoshi Watanabe

For the first time by using the ab initio density functional theory, the stability and electronic structures of germanene on monolayer GaS, GaSe, GaTe and InSe have been investigated.


Author(s):  
Alhassan Shuaibu ◽  
Yakubu Tanko ◽  
Zainab Abdurrahman ◽  
Abdullahi Lawal ◽  
Maharaz Nasir

Stanene is a quantum spin hall insulator and a favourable material for electronic and optoelectronic devices. Density functional theory (DFT) calculations are performed to study the band gap opening in stanene by investigating the effect of beryllium and magnesium doped stanene single layer to study the electronic and structural properties in stanene. The electronic band energy of pure stanene without spin orbit coupling (SOC) appear to show no energy gap at the Fermi level showing that stanene is a gapless material with Dirac cones at the K point and the band gap opens by a gap of 0.08 eV is opened at the K point. The electronic structure of Be and Mg doped stanene shows that the Fermi level is shifted towards the valance band edge when compared to pure stanene. We have considered 6.25, 12.5, 18.75 and 25% of both Be and mg doping. The electronic structure of Be doped stanene show that the Fermi level is shifted towards the valance band edge when compared to pure stanene. The Dirac point of stanene locates at Γ shifted by 0.38 and 0.51eV for 6.25 and 12.5 %, an energy band gap of 0.27 and 0.50 eV were obtained above the Fermi level for 6.25 and 12.5% respectively. In the case of Mg, the bandgap remains slightly above the Fermi-level and amounts to 0.34 eV for 6.25 % and 0.43eV for 12.5 %, in the case of 18.75 and 25 % the Dirac cone disappear completely, an energy gap of 0.28 eV and 0.60 eV were obtained above the Fermi level for 6.25 and 12.5% respectively, our findings show that the band gap of stanene open at 12.5% doping concentration of both Be and Mg impurities. These obtained band-gap value seem to be sufficient for use of alkaline earth metal doped stanene in optoelectronic and such applications where stanene is incapacitate for its use to switch on/off devices.


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