A New Approach for Calculating the Band Gap of Semiconductors within the Density Functional Method

2015 ◽  
Vol 242 ◽  
pp. 434-439 ◽  
Author(s):  
Vasilii E. Gusakov
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Density Functional ◽  
Density Functional Method ◽  
Functional Method ◽  
Localized States ◽  
Experimental Accuracy ◽  
Functional Theory ◽  
New Approach ◽  
The Density Functional Theory

Within the framework of the density functional theory, the method was developed to calculate the band gap of semiconductors. We have evaluated the band gap for a number of monoatomic and diatomic semiconductors (Sn, Ge, Si, SiC, GaN, C, BN, AlN). The method gives the band gap of almost experimental accuracy. An important point is the fact that the developed method can be used to calculate both localized states (energy deep levels of defects in crystal), and electronic properties of nanostructures.

Electronic structure and magnetic ordering in gadolinium-doped AlGaN from LSDA + U calculations

2018 ◽  
Vol 07 (03) ◽  
pp. 1850019 ◽  
Author(s):  
S. Belhachi ◽  
S. Amari ◽  
B. Bouhafs
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Band Gap ◽  
First Principles ◽  
Density Functional ◽  
Magnetic Ordering ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Indirect Band Gap

We present first-principles calculations of the structural, electronic and magnetic properties of Gd-doped [Formula: see text] based on the density functional theory within [Formula: see text] schemes. It is found that Gd atom favors substituting for Al site. Compared with undoped [Formula: see text], the Gd-doped [Formula: see text] has become an indirect band gap semiconductor of reduced band gap. The magnetic moment [Formula: see text] per molecule mainly comes from Gd ion with little contribution from the Ga, Al and N atoms. It is confirmed that the ferromagnetic configuration is stable for [Formula: see text]. It is found also that there is hybridization between the forbital of the Gd atom and the [Formula: see text] orbital of the N atom.

scholarly journals Density Functional Theory Calculation of Band Gap of Iron (II) disulfide and Tellurium

2017 ◽  
Vol 3 (1) ◽  
pp. 41-46
Author(s):  
Arumona Edward Arumona ◽  
Amah A N
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Density Functional ◽  
Density Functional Theory Calculation ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Theory Calculation

In this work, the band gap of Iron(II) disulfide and Tellurium were computed using the density functional theory with different meta-GGA functionals. The results showed that the meta-GGA functional M06L gave the closest value of the band gap as 0.96 eV compared to the experimental value of 0.95 eV for Iron(II) disulfide while the meta-GGA functional BJ06 gave the closest value of the band gap as 0.339 eV compared to the experimental value of     0.335 eV for Tellurium. This study showed that the meta-GGA functionals M06L and BJ06 can effectively predict the band gap of Iron(II)disulfide and Tellurium. In general, the use of meta-GGA functionals can be extended to compute the band gap of other semiconductors.

scholarly journals Disordered small defect clusters in silicon

2016 ◽  
Vol 55 (4) ◽  
Author(s):  
Ernestas Žąsinas ◽  
Juozas Vidmantis Vaitkus
Keyword(s):  
Band Gap ◽  
Density Functional ◽  
Energy Levels ◽  
Density Functional Method ◽  
Shallow Donor ◽  
Functional Method ◽  
Localized States ◽  
Defect Clusters ◽  
Small Defect ◽  
Donor And Acceptor

The ionizing radiation induced disordered defect clusters and their relaxation in silicon were simulated by the density functional method. It was found that a non-relaxed disordered cluster gives rise to a great number of localized states having their energy levels within the semiconductor forbidden band gap. After the relaxation, however, the density of these states significantly decreases leaving only several relatively shallow donor and acceptor state levels that may contribute to trapping of free carriers and shrinkage of an effective band gap.

Electronic Properties of Doped Wurtzite ZnO: Density Functional Theory

2020 ◽  
Vol 65 (3) ◽  
pp. 268 ◽  
Author(s):  
Jamal A. Talla
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Nitrogen Concentration ◽  
Functional Theory ◽  
Nitrogen Doped ◽  
The Density Functional Theory ◽  
Hubbard U ◽  
Doped Zno

We implemented the density functional theory to inspect the electronic properties of pristine and nitrogen-doped wurtzite ZnO. We use the Hubbard U (DFT + Ud + Up) method to correct any underestimation in the band gap. The obtained band gap is consistent with previous experimental results. Here, we consider four different configurations of nitrogen-doped ZnO. We have found that the band gap values for ZnO are sensitive to the nitrogen concentration.

scholarly journals Electron-phonon interaction in In-induced √7 ×√3 structures on Si(111) from first-principles

2021 ◽  
Author(s):  
I. Yu. Sklyadneva ◽  
Rolf Heid ◽  
Pedro Miguel Echenique ◽  
Evgueni Chulkov
Keyword(s):  
Density Functional Theory ◽  
Double Layer ◽  
First Principles ◽  
Linear Response ◽  
Density Functional ◽  
Single Layer ◽  
Phonon Interaction ◽  
Functional Theory ◽  
Electron Phonon Interaction ◽  
The Density Functional Theory

Electron-phonon interaction in the Si(111)-supported rectangular √(7 ) ×√3 phases of In is investigated within the density-functional theory and linear-response. For both single-layer and double-layer √(7 ) ×√3 structures, it...

scholarly journals Study on the interaction between catechin and cholesterol by the density functional theory

2020 ◽  
Vol 18 (1) ◽  
pp. 357-368
Author(s):  
Kaiwen Zheng ◽  
Kai Guo ◽  
Jing Xu ◽  
Wei Liu ◽  
Junlang Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Charge Transfer ◽  
Density Functional ◽  
Antioxidant Properties ◽  
Micelle Formation ◽  
Aromatic Rings ◽  
Hydrogen Bond Interaction ◽  
Functional Theory ◽  
The Density Functional Theory

AbstractCatechin – a natural polyphenol substance – has excellent antioxidant properties for the treatment of diseases, especially for cholesterol lowering. Catechin can reduce cholesterol content in micelles by forming insoluble precipitation with cholesterol, thereby reducing the absorption of cholesterol in the intestine. In this study, to better understand the molecular mechanism of catechin and cholesterol, we studied the interaction between typical catechins and cholesterol by the density functional theory. Results show that the adsorption energies between the four catechins and cholesterol are obviously stronger than that of cholesterol themselves, indicating that catechin has an advantage in reducing cholesterol micelle formation. Moreover, it is found that the molecular interactions of the complexes are mainly due to charge transfer of the aromatic rings of the catechins as well as the hydrogen bond interactions. Unlike the intuitive understanding of a complex formed by hydrogen bond interaction, which is positively correlated with the number of hydrogen bonds, the most stable complexes (epicatechin–cholesterol or epigallocatechin–cholesterol) have only one but stronger hydrogen bond, due to charge transfer of the aromatic rings of catechins.

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