Coupled Electron–Hole Quantum Dynamics on D−π–A Dye-Sensitized TiO2 Semiconductors

2012 ◽  
Vol 116 (40) ◽  
pp. 21169-21178 ◽  
Author(s):  
Diego A. Hoff ◽  
Robson da Silva ◽  
Luis G. C. Rego
Keyword(s):  
Quantum Dynamics ◽  
Electron Hole ◽  
Dye Sensitized

scholarly journals Construction of NiMoS3/BC heterostructure photoanodes and optimization of light scattering to improve the photovoltaic performance of dye sensitized solar cells (DSSCs)

2021 ◽  
Author(s):  
T Sumathi ◽  
Sonia A Fredricka ◽  
G Deepa
Keyword(s):  
Solar Cells ◽  
Large Scale ◽  
Photovoltaic Performance ◽  
Dye Sensitized Solar Cells ◽  
Photocurrent Density ◽  
Electron Hole ◽  
Dye Sensitized ◽  
Electron Hole Pair ◽  
Conversion Efficiencies ◽  
Sensitized Solar Cells

Abstract In the last two decades, dye sensitized solar cells (DSSCs) have gotten a lot of attention from researchers and have progressed quickly. To promote commercialization and large-scale application of DSSCs, their efficiency should be increased. This paper details significant advancements in advanced NiMoS3/BC nanocomposites for improving photoanodes and DSSC conversion efficiencies. The fabricated electrode samples were characterized by XRD, SEM, TEM, Raman, UV, PL and BET to explore the structural, morphological and optical properties. A significant reduction band gap with enhanced light absorption and rapid prevention of electron hole pair was explored by UV-DRS and PL studies. The photocurrent density-voltage (J-V) and IPCE characteristics were analyzed for assembled solar cell. The NiMoS3/BC (NMSC5) nanocomposite DSSC showed a PCE of 8.85%, far higher than that of the NiMoS3 (2.45%) and a PCE value equivalent to Pt CE (4.79 %). The enhanced PCE of the proposed electrodes are also discussed in scientifically.

scholarly journals Molybdenum trioxide thin film recombination barrier layers for dye sensitized solar cells

RSC Advances ◽  
2017 ◽  
Vol 7 (77) ◽  
pp. 48853-48860 ◽  
Author(s):  
Aditya Ashok ◽  
S. N. Vijayaraghavan ◽  
Shantikumar V. Nair ◽  
Mariyappan Shanmugam
Keyword(s):  
Thin Film ◽  
Charge Transport ◽  
Barrier Layer ◽  
Molybdenum Trioxide ◽  
Dye Sensitized Solar Cells ◽  
Electron Hole ◽  
Barrier Layers ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Hole Recombination

MoO3 thin film recombination barrier layer suppresses electron–hole recombination at the FTO–TiO2 interface and facilitates charge transport.

Unraveling the quantum dynamics origin of high photocatalytic activity in nitrogen-doped anatase TiO2: time-domain ab initio analysis

2020 ◽  
Vol 8 (47) ◽  
pp. 25235-25244
Author(s):  
Yating Yang ◽  
Zhaosheng Zhang ◽  
Wei-Hai Fang ◽  
Sebastian Fernandez-Alberti ◽  
Run Long
Keyword(s):  
Photocatalytic Activity ◽  
Ab Initio ◽  
Time Domain ◽  
Quantum Dynamics ◽  
High Photocatalytic Activity ◽  
Anatase Tio2 ◽  
Electron Hole ◽  
Nitrogen Doped ◽  
Hole Recombination

TiO2 doping with nitrogen greatly suppresses nonradiative electron-hole recombination and enhances photocatalytic activity.

scholarly journals Symmetry selected quantum dynamics of few electrons in nanopillar transistors

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yue-Min Wan ◽  
Heng-Tien Lin
Keyword(s):  
Quantum Number ◽  
Quantum Dynamics ◽  
Three Dimensional ◽  
Single Electron ◽  
Electron Hole ◽  
Current Voltage ◽  
Weak Symmetry ◽  
Current Voltage Characteristics ◽  
The One

AbstractStudy on single electron tunnel using current-voltage characteristics in nanopillar transistors at 298 K show that the mapping between the Nth electron excited in the central box ∼8.5 × 8.5 × 3 nm3 and the Nth tunnel peak is not in the one-to-one correspondence to suggest that the total number N of electrons is not the best quantum number for characterizing the quality of single electron tunnel in a three-dimensional quantum box transistor. Instead, we find that the best number is the sub-quantum number nz of the conduction z channel. When the number of electrons in nz is charged to be even and the number of electrons excited in the nx and ny are also even at two, the adding of the third electron into the easy nx/ny channels creates a weak symmetry breaking in the parity conserved x-y plane to assist the indirect tunnel of electrons. A comprehensive model that incorporates the interactions of electron-electron, spin-spin, electron-phonon, and electron-hole is proposed to explain how the excited even electrons can be stabilized in the electric-field driving channel. Quantum selection rules with hierarchy for the ni (i = x, y, z) and N = Σni are tabulated to prove the superiority of nz over N.

scholarly journals Improvement of Dye Solar Cell Efficiency by Photoanode Posttreatment

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Tanja Ivanovska ◽  
Zoran Saponjic ◽  
Marija Radoicic ◽  
Luca Ortolani ◽  
Vittorio Morandi ◽  
...  
Keyword(s):  
Dye Sensitized Solar Cells ◽  
Trap States ◽  
Electron Recombination ◽  
Electron Hole ◽  
Surface Trap ◽  
Solar Cell Efficiency ◽  
Cell Efficiency ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Hole Recombination

The basic concept for efficiency improvement in dye-sensitized solar cells (DSSC) is limiting the electron-hole recombination. One way to approach the problem is to improve the photogenerated charge carriers lifetime and consequently reduce their recombination probability. We are reporting on a facile posttreatment of the mesoporous photoanode by using a colloidal solution of TiO2nanoparticles. We have investigated the outcome of the different sintering temperature of the posttreated photoanodes on their morphology as well as on the conversion efficiency of the DSSC. The DSSCs composed of posttreated photoanodes at 450°C showed an increase inJSCand consequently an increase in efficiency of 10%. Investigations were made to determine the electron recombination via the electrolyte by the OCVD technique. We found that the posttreatment has the effect of reducing the surface trap states and thus increases the electron lifetime, which is responsible for the increase of the overall cell efficiency.

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 Quantum Dynamics of Electron–Hole Separation in Stacked Perylene Diimide-Based Self-Assembled Nanostructures

2021 ◽  
Author(s):  
Dominik Brey ◽  
Wjatscheslaw Popp ◽  
Praveen Budakoti ◽  
Gabriele D’Avino ◽  
Irene Burghardt
Keyword(s):  
Quantum Dynamics ◽  
Perylene Diimide ◽  
Electron Hole ◽  
Self Assembled
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