scholarly journals Remarkable charge-transfer mobility from [6] to [10]phenacene as a high performance p-type organic semiconductor

2018 ◽  
Vol 20 (13) ◽  
pp. 8658-8667 ◽  
Author(s):  
Thao P. Nguyen ◽  
P. Roy ◽  
Ji Hoon Shim
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Organic Semiconductors ◽  
High Performance ◽  
Density Functional ◽  
Dft Calculation ◽  
High Efficiency ◽  
Electronic Devices ◽  
Functional Theory ◽  
P Type

A density functional theory (DFT) calculation predicts phenacene as one of the most promising organic semiconductors for high efficiency electronic devices.

ACHIEVING P-TYPE SEMICONDUCTING ZnO NANOWIRES VIA DONOR ADSORPTION

2013 ◽  
Vol 12 (03) ◽  
pp. 1350014
Author(s):  
DIHUA WU ◽  
ZHEN ZHOU
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electronic Devices ◽  
Zno Nanowires ◽  
Facile Synthesis ◽  
Functional Theory ◽  
Synthesis Route ◽  
Density Functional Theory Computations ◽  
P Type ◽  
Formation Energies

The difficulty of achieving p-type conductance has severely limited the application of ZnO to electronic devices. In this work, we propose a simple and effective way to achieving p-type semiconducting ZnO nanowires (NWs) through density functional theory computations. Adsorption of tetrathiafulvalene (TTF) during synthetic procedures leads to lower formation energies, and accordingly higher concentration of p-type defects; after the formation of ZnO NWs and the desorption of TTF, p-type ZnO NWs can be achieved. Also, we present a facile synthesis route on basis of previous experiments, which provides some guidance for the realization of p-type ZnO NWs.

Description of Intermolecular Charge Transfer With Subsystem Density-Functional Theory

2019 ◽  
Author(s):  
Anika Schulz ◽  
Christoph R. Jacob
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Test Case ◽  
Correct Description ◽  
Functional Theory ◽  
Fractional Charge ◽  
Intermolecular Charge Transfer ◽  
Model Complex

Efficient quantum-chemical methods that are able to describe intermolecular charge are crucial for modeling organic semiconductors. However, the correct description of intermolecular charge transfer with density-functional theory (DFT) is hampered by the fractional charge error of approximate exchange-correlation (xc) functionals. Here, we investigate the charge transfer induced by an external electric field in a tetrathiafulvalene--tetracyanoquinodimethane (TTF--TCNQ) complex as a test case. For this seemingly simple model system, a supermolecular DFT treatment fails with most conventional xc functionals. Here, we present an extension of subsystem DFT to subsystems with a fractional number of electrons. We show that within such a framework it becomes possible to overcome the fractional charge error by enforcing the correct dependence of each subsystem's total energy on the subsystem's fractional charge. Such a subsystem DFT approach allows for a correct description of the intermolecular charge transfer in the TTF--TCNQ model complex. The approach presented here can be generalized to larger molecular aggregates and will thus allow for modeling organic semiconductor materials accurately and efficiently. <br>

scholarly journals First Principles Investigations on the Electronic and Magnetic Properties of La4Ba2Cu2O10

2016 ◽  
Vol 3 (1) ◽  
pp. 89 ◽  
Author(s):  
Shalika Ram Bhandari ◽  
Ram Kumar Thapa ◽  
Madhav Prasad Ghimire
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Charge Transfer ◽  
Magnetic Moment ◽  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Dft Calculation ◽  
Functional Theory ◽  
Electronic And Magnetic Properties

<p>Electronic and magnetic properties of La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub> had been studied by first-principles density functional theory (DFT). Based on the DFT calculation La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub> is found to have a ferromagnetic (FM) ground state. The material undergo charge-transfer type insulator to Mott-Hubbard type insulator transition which happens due to strong correlation in La-4f and Cu-3d states. Our results show that the 3d electrons of Cu hybridize strongly with O-2p states near the Fermi level giving rise to the insulating state of La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub>. Our study suggests that the enhanced magnetic moment is a result of itinerant exchange rather than the exchange interaction involving individual ions of Cu atoms. The total magnetic moment calculated in the present studies is 2 μ<sub>B</sub> per unit cell for La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub>.</p><p>Journal of Nepal Physical Society Vol.3(1) 2015: 89-96</p>

Description of Intermolecular Charge Transfer With Subsystem Density-Functional Theory

2019 ◽  
Author(s):  
Anika Schulz ◽  
Christoph R. Jacob
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Organic Semiconductors ◽  
Density Functional ◽  
Test Case ◽  
Correct Description ◽  
Functional Theory ◽  
Fractional Charge ◽  
Intermolecular Charge Transfer ◽  
Model Complex

Efficient quantum-chemical methods that are able to describe intermolecular charge are crucial for modeling organic semiconductors. However, the correct description of intermolecular charge transfer with density-functional theory (DFT) is hampered by the fractional charge error of approximate exchange-correlation (xc) functionals. Here, we investigate the charge transfer induced by an external electric field in a tetrathiafulvalene--tetracyanoquinodimethane (TTF--TCNQ) complex as a test case. For this seemingly simple model system, a supermolecular DFT treatment fails with most conventional xc functionals. Here, we present an extension of subsystem DFT to subsystems with a fractional number of electrons. We show that within such a framework it becomes possible to overcome the fractional charge error by enforcing the correct dependence of each subsystem's total energy on the subsystem's fractional charge. Such a subsystem DFT approach allows for a correct description of the intermolecular charge transfer in the TTF--TCNQ model complex. The approach presented here can be generalized to larger molecular aggregates and will thus allow for modeling organic semiconductor materials accurately and efficiently. <br>

On the Nature of Halide-Water Interactions: Insights from Many-Body Representations and Density Functional Theory

2019 ◽  
Author(s):  
Brandon B. Bizzarro ◽  
Colin K. Egan ◽  
Francesco Paesani
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Molecular Orbital ◽  
Density Functional ◽  
Decomposition Analysis ◽  
Orbital Energy ◽  
Energy Decomposition Analysis ◽  
Interaction Energies ◽  
Many Body ◽  
Functional Theory

<div> <div> <div> <p>Interaction energies of halide-water dimers, X<sup>-</sup>(H<sub>2</sub>O), and trimers, X<sup>-</sup>(H<sub>2</sub>O)<sub>2</sub>, with X = F, Cl, Br, and I, are investigated using various many-body models and exchange-correlation functionals selected across the hierarchy of density functional theory (DFT) approximations. Analysis of the results obtained with the many-body models demonstrates the need to capture important short-range interactions in the regime of large inter-molecular orbital overlap, such as charge transfer and charge penetration. Failure to reproduce these effects can lead to large deviations relative to reference data calculated at the coupled cluster level of theory. Decompositions of interaction energies carried out with the absolutely localized molecular orbital energy decomposition analysis (ALMO-EDA) method demonstrate that permanent and inductive electrostatic energies are accurately reproduced by all classes of XC functionals (from generalized gradient corrected (GGA) to hybrid and range-separated functionals), while significant variance is found for charge transfer energies predicted by different XC functionals. Since GGA and hybrid XC functionals predict the most and least attractive charge transfer energies, respectively, the large variance is likely due to the delocalization error. In this scenario, the hybrid XC functionals are then expected to provide the most accurate charge transfer energies. The sum of Pauli repulsion and dispersion energies are the most varied among the XC functionals, but it is found that a correspondence between the interaction energy and the ALMO EDA total frozen energy may be used to determine accurate estimates for these contributions. </p> </div> </div> </div>

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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