Exciton delocalization and hot hole extraction in CdSe QDs and CdSe/ZnS type 1 core shell QDs sensitized with newly synthesized thiols.
@article{Singhal2016ExcitonDA,
title={Exciton delocalization and hot hole extraction in CdSe QDs and CdSe/ZnS type 1 core shell QDs sensitized with newly synthesized thiols.},
author={Pallavi Singhal and Prashant Vasantrao Ghorpade and Ganapati Subray Shankarling and Nancy Singhal and Sanjay K. Jha and Raj M. Tripathi and Hirendra Nath Ghosh},
journal={Nanoscale},
year={2016},
volume={8 4},
pages={
1823-33
}
}The present work describes ultrafast thermalized and hot hole transfer processes from photo-excited CdSe quantum dots (QDs) and CdSe/ZnS core-shell QDs (CSQDs) to newly synthesized thiols. Three thiols namely 2-mercapto-N-phenylacetamide (AAT), 3-mercapto-N-phenylpropanamide (APT) and 3-mercapto-N-(4-methoxyphenyl) propanamide (ADPT) were synthesized and their interaction with both CdSe QDs and CdSe/ZnS CSQDs was monitored. Steady state absorption study suggests the exciton delocalization from…
18 Citations
Excited Hole Photochemistry of CdSe/CdS Quantum Dots
- Chemistry, Physics
- 2016
One-photon excitation of CdSe/CdS quantum dots (QDs) in room-temperature chloroform results in a delayed and reversible photodarkening of the sample. There is little or no prompt loss of…
Strategy for performance enhancement of Cd1-XZnXTe/CdS core/shell quantum dot sensitized solar cells through band adjustment
- Materials Science, ChemistryJournal of Alloys and Compounds
- 2020
Metal-Ligand Complex-Induced Ultrafast Charge-Carrier Relaxation and Charge-Transfer Dynamics in CdX (X=S, Se, Te) Quantum Dots Sensitized with Nitrocatechol.
- Chemistry, PhysicsChemistry
- 2017
A strong metal-ligand complex formation on QDs surface that controls charge carrier dynamics in QDs/molecular adsorbate system and to the best of the knowledge it has never been reported is suggested.
Surface Modification of CdSe Quantum Dots/Titanium Dioxide Heterostructures by Conjugated Organic Ligands
- Chemistry
- 2020
Improving the charge transfer of quantum dots and the electron transport layer can greatly improve the efficiency of quantum dot sensitized solar cells (QDSSC). In this work, we used the ligand…
Ultrafast Photoluminescence Kinetics from Hot Excitonic States in CdSe Nanocrystals
- PhysicsThe Journal of Physical Chemistry C
- 2018
The evolution of transient emissions from higher energy excitonic states of core CdSe quantum dots of 4.4 and 5.4 nm diameters was investigated via femtosecond up-conversion measurements, with a high…
Correlating Charge-Carrier Dynamics with Efficiency in Quantum-Dot Solar Cells: Can Excitonics Lead to Highly Efficient Devices?
- Physics, ChemistryChemistry
- 2019
This Minireview summarizes some proof of the concepts that efficiency can be directly correlated to the exciton dynamics of quantum-dot solar cells, based on CdSeS alloy, C dSe/CdS core/shell, Au/C dSe nanohybrids, and Mn-doped CdZnSSe nanocrystals, where the favourable excitonic processes are optimized to enhance the efficiency.
Green, Water-Dispersible Photoluminescent On-Off-On Probe for Selective Detection of Fluoride Ions.
- Materials ScienceACS applied materials & interfaces
- 2017
This is the first report based on CQDs and Eu3+ for the detection of fluoride ions, wherein a clear mechanism of the detection has been demonstrated and will help to develop better detection methods.
Hydrophilic, Hole-Delocalizing Ligand Shell to Promote Charge Transfer from Colloidal CdSe Quantum Dots in Water
- Chemistry
- 2017
Colloidal cadmium chalcogenide nanocrystals are usually stabilized in polar solvents by functionalizing the surface with a layer of hydrophilic ligands. While these ligands protect against…
Electron-Transfer-Mediated Uranium Detection Using Quasi-Type II Core-Shell Quantum Dots: Insight into Mechanistic Pathways.
- Environmental ScienceLangmuir : the ACS journal of surfaces and colloids
- 2017
This work is reporting for the first time uranium detection using quasi-type II CSQDs and proposing the mechanistic path through luminescence spectroscopy, which in turn helps to design an efficient detection method.
Synthesis, nonlinear optical properties and cellular imaging of hybrid ZnS nanoparticles capped with conjugated terpyridine derivatives
- ChemistryJournal of Materials Science
- 2017
A novel organic/inorganic nanohybrids which consisted of ligand L (L = 2-[(2-hydroxy-ethyl)-(4-[2,2′;6′,2″] terpyridin-4′-yl-phenyl)-amino]-ethanol), an optical terpyridine derivative and ZnS…
References
SHOWING 1-10 OF 50 REFERENCES
Super sensitization: grand charge (hole/electron) separation in ATC dye sensitized CdSe, CdSe/ZnS type-I, and CdSe/CdTe type-II core-shell quantum dots.
- Physics, ChemistryChemistry
- 2014
Energy level diagrams suggest that the conduction and valence band of CdSe lies below the LUMO and the HOMO level of ATC, respectively, thus signifying that the photoexcited hole in Cd Se can be transferred to ATC and that photoexcite ATC can inject electrons into Cdse QD, which suggests the potential of quantum dot core-shell super sensitizers for developing more efficient quantum dot solar cells.
Ultrafast Hole/Electron Transfer Dynamics in a CdSe Quantum Dot Sensitized by Pyrogallol Red: A Super-Sensitization System
- Physics, Chemistry
- 2014
To find a suitable hole-transporting adsorbate for CdSe quantum dots (QDs), a pyrogallol red (PGR) molecule was chosen where PGR also can sensitize CdSe QDs. Energy level diagrams suggest that the…
Spectroscopy and femtosecond dynamics of water soluble type I CdSe/ZnS core–shell quantum dot
- Physics, Chemistry
- 2013
Thiol-capped type I CdSe/ZnS core–shell quantum dot nanostructures have been synthesized at low temperature in water; and then characterized by steady-state absorption and photoluminescence (PL)…
Exciton Dissociation in CdSe Quantum Dots by Hole Transfer to Phenothiazine
- Chemistry, Physics
- 2008
Ultrafast charge transfer from quantum dots (QDs) is essential for their application in solar cells. Photoinduced hole transfer from CdSe QDs (with first exciton peak at 462 nm and estimated radius…
Electron Trap to Electron Storage Center in Specially Aligned Mn-Doped CdSe d-Dot: A Step Forward in the Design of Higher Efficient Quantum-Dot Solar Cell.
- Chemistry, PhysicsThe journal of physical chemistry letters
- 2014
The MnCdSe/Br-PGR system can be used as a better super sensitizer in quantum-dot-sensitized solar cell to increase efficiency further and confirms that the Mn dopant act as the electron storage center.
Hot-hole extraction from quantum dot to molecular adsorbate.
- ChemistryChemistry
- 2015
Ultrafast thermalized and hot-hole-transfer processes have been investigated in CdSe quantum dot (QD)/catechol composite systems in which hole transfer from photoexcited QDs to the catechols is…
Ultrafast Hole- and Electron-Transfer Dynamics in CdS–Dibromofluorescein (DBF) Supersensitized Quantum Dot Solar Cell Materials
- Physics, Chemistry
- 2013
Ultrafast charge-transfer (CT) dynamics has been demonstrated in CdS quantum dot (QD)–4′,5′-dibromofluorescein (DBF) composite materials, which form a strong CT complex in the ground state. Charge…
CdSe/ZnS core/shell quantum dot sensitization of low index TiO(2) single crystal surfaces.
- Chemistry, Materials ScienceJournal of the American Chemical Society
- 2010
It is demonstrated that type-I CdSe/ZnS CS QDs can effectively sensitize single crystal TiO(2) electrodes and continue to operate in a regenerative mode in an aerated iodide electrolyte for more than 20 h.
Controlling charge separation and recombination rates in CdSe/ZnS type I core-shell quantum dots by shell thicknesses.
- Chemistry, PhysicsJournal of the American Chemical Society
- 2010
Type I core/shell quantum dots (QDs) have been shown to improve the stability and conversion efficiency of QD-sensitized solar cells compared to core only QDs. To understand how the shell thickness…
Hole Transfer from Low Band Gap Quantum Dots to Conjugated Polymers in Organic/Inorganic Hybrid Photovoltaics.
- Chemistry, PhysicsThe journal of physical chemistry letters
- 2013
This work finds that positively charged polarons are formed on the conjugated polymer following selective photoexcitation of the PbS quantum dots and provides a direct spectroscopic fingerprint demonstrating that photoinduced hole transfer occurs from the photoexcited quantum dots to the host polymer.