scholarly journals Electron-hole spectra created by adsorption on metals from density functional theory

2009 ◽  
Vol 79 (16) ◽  
Author(s):  
Matthias Timmer ◽  
Peter Kratzer
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electron Hole ◽  
Functional Theory

scholarly journals A Theoretical Evaluation of the Efficiencies of Metal-Free 1,3,4-Oxadiazole Dye-Sensitized Solar Cells: Insights From Electron-Hole Separation Distance Analysis.

2021 ◽  
Author(s):  
Louis-Charl Coetzee ◽  
Adedapo Adeyinka ◽  
Nomampondo Magwa
Keyword(s):  
Density Functional Theory ◽  
Solar Cells ◽  
Density Functional ◽  
Dye Sensitized Solar Cells ◽  
Separation Distance ◽  
Electron Hole ◽  
Functional Theory ◽  
Metal Free ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

Abstract Herein, some novel metal-free 1,3,4-oxadiazole compounds O1-O7 were evaluated for Photovoltaic properties using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations to determine if they can serve as metal-free organic dyes for the use of dye-sensitized solar cells (DSSCs). To understand the trends in the relative efficiencies of the investigated compounds as dyes in DSSCs, their electron contributions, hole contributions, and electron-hole overlaps for each respective atom and fragment within the molecule were analyzed with a particular focus on the electron densities on the anchoring segments. As transition density matrices (TDM) provide details for the departure of each electron from its corresponding hole during excitations, which results in charge transfer (CT), the charge separation distance (Δr) between the electron and its corresponding hole was studied as well as the degree of electron-hole overlap (Ʌ). The latter, single-point excitation energy of each electron, the percentage electron contribution to the anchoring segments of each compound, the incident-photon-conversion-efficiency (IPCE), charge recombination, light harvesting efficiency (LHE) electron injection (Φinj) and charge collection efficiency (ncollect) were then compared to Δr to determine whether the expected relationships hold. Moreover, parameters such as diffusion constant (Dπ) and electron lifetime (t), amongst others, were also used to describe electron excitation processes. Since IPCE is the key parameter in determining the efficiency, O3 was found to be the best dye due to its highest value.

scholarly journals Heterostructures of ε-Fe2O3 and α-Fe2O3: insights from density functional theory

RSC Advances ◽  
2020 ◽  
Vol 10 (46) ◽  
pp. 27474-27480
Author(s):  
Imran Ahamed ◽  
Nicola Seriani ◽  
Ralph Gebauer ◽  
Arti Kashyap
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Hole Pair ◽  
Electron Hole ◽  
Functional Theory ◽  
Electron Hole Pair ◽  
Single Material

Electron–hole pair recombination is reduced in heterostructures if used in devices in place of single material.

Density functional theory of two-dimensional electron–hole complexes

2019 ◽  
Vol 33 (12) ◽  
pp. 1950152
Author(s):  
Alexander A. Vasilchenko
Keyword(s):  
Magnetic Field ◽  
Density Functional Theory ◽  
Density Functional ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Electron Hole ◽  
Functional Theory ◽  
Exchange Correlation ◽  
The Density Functional Theory ◽  
Number Of Particles

The energy of the two-dimensional electron–hole complex has been calculated in the framework of the density functional theory. We show that the energy of a direct two-dimensional exciton, without taking into consideration the exchange–correlation interaction, is very different from the exact value. We find that the number of particles in the indirect electron–hole complexes decreases with increasing interlayer distance in a strong magnetic field.

Doping effects on the geometric and electronic structure of tin clusters

2019 ◽  
Vol 21 (44) ◽  
pp. 24478-24488 ◽  
Author(s):  
Martin Gleditzsch ◽  
Marc Jäger ◽  
Lukáš F. Pašteka ◽  
Armin Shayeghi ◽  
Rolf Schäfer
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Beam Deflection ◽  
Functional Theory ◽  
Doping Effects ◽  
Depth Analysis ◽  
Trajectory Simulations

In depth analysis of doping effects on the geometric and electronic structure of tin clusters via electric beam deflection, numerical trajectory simulations and density functional theory.

What correlation effects are covered by density functional theory?

2000 ◽  
Vol 98 (20) ◽  
pp. 1639-1658 ◽  
Author(s):  
Yuan He, Jurgen Grafenstein, Elfi Kraka,
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Correlation Effects ◽  
Functional Theory
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