Studying the role of CdS on the TiO2 surface passivation to improve CdSeTe quantum dots sensitized solar cell

2017 ◽  
Vol 728 ◽  
pp. 1058-1064 ◽  
Author(s):  
Diego Esparza ◽  
Guillermo Bustos-Ramirez ◽  
Ramón Carriles ◽  
Tzarara López-Luke ◽  
Isaac Zarazúa ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cell ◽  
Surface Passivation ◽  
Tio2 Surface

scholarly journals Influence of TOPO and TOPO-CdSe/ZnS Quantum Dots on Luminescence Photodynamics of InP/InAsP/InPHeterostructure Nanowires

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 640
Author(s):  
Artem I. Khrebtov ◽  
Vladimir V. Danilov ◽  
Anastasia S. Kulagina ◽  
Rodion R. Reznik ◽  
Ivan D. Skurlov ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Excited States ◽  
Molecular Beam ◽  
Surface Passivation ◽  
Low Energy ◽  
Trioctylphosphine Oxide ◽  
Reverse Transfer ◽  
Semiconductor Heterostructure ◽  
Ligand Type

The passivation influence by ligands coverage with trioctylphosphine oxide (TOPO) and TOPO including colloidal CdSe/ZnS quantum dots (QDs) on optical properties of the semiconductor heterostructure, namely an array of InP nanowires (NWs) with InAsP nanoinsertion grown by Au-assisted molecular beam epitaxy on Si (111) substrates, was investigated. A significant dependence of the photoluminescence (PL) dynamics of the InAsP insertions on the ligand type was shown, which was associated with the changes in the excitation translation channels in the heterostructure. This change was caused by a different interaction of the ligand shells with the surface of InP NWs, which led to the formation of different interfacial low-energy states at the NW-ligand boundary, such as surface-localized antibonding orbitals and hybridized states that were energetically close to the radiating state and participate in the transfer of excitation. It was shown that the quenching of excited states associated with the capture of excitation to interfacial low-energy traps was compensated by the increasing role of the “reverse transfer” mechanism. As a result, the effectiveness of TOPO-CdSe/ZnS QDs as a novel surface passivation coating was demonstrated.

Optical and Electron Correlation Effects in Silicon Quantum Dots

2005 ◽  
Vol 23 ◽  
pp. 129-132 ◽  
Author(s):  
S.K. Ghoshal ◽  
K.P. Jain ◽  
R. Elliott
Keyword(s):  
Quantum Dots ◽  
Band Gap ◽  
Surface Passivation ◽  
Surface States ◽  
Hydrogen Atoms ◽  
Basis Expansion ◽  
Electron Correlation Effects ◽  
Homo Lumo ◽  
Pseudo Potential

We study (through computer simulation) the variation of the band gap as a function of sizes and shapes of small Silicon (Si) dots using pseudo-potential approach. We have used empirical pseudo-potential Hamiltonian and a plane wave basis expansion and a basic tetrahedral structure. It is found that the gap decreases for increasing dot size. Furthermore, the band gap increases as much as 0.13eV on passivation the surface of the dot with hydrogen. So both quantum confinement and surface passivation determine the optical and electronic properties of Si quantum dots. Visible luminescence is probably due to radiative recombination of electrons and holes in the quantum confined nanostructures. The effect of passivation of the surface dangling bonds by hydrogen atoms and the role of surface states on the gap energy as well as on the HOMO-LUMO states has also been examined. We have investigated the entire energy spectrum starting from the very low lying ground state to the very high lying excited states for silicon dots having 5, 18, 17 and 18 atoms. The results for the size dependence of the HOMO-LUMO gap and the wave functions for the bonding-antibonding states are presented and the importance of the confinement and the role of hydrogen passivation on the confinement are also discussed.

Role of Cation-Anion Organic Ligands for Optical Properties of Fully Inorganic Perovskite Quantum Dots

MRS Advances ◽  
2018 ◽  
Vol 3 (55) ◽  
pp. 3255-3261 ◽  
Author(s):  
Aaron Forde ◽  
Talgat Inerbaev ◽  
Dmitri Kilin
Keyword(s):  
Quantum Dots ◽  
Surface Passivation ◽  
Binding Energies ◽  
Organic Ligands ◽  
Trap States ◽  
Light Emitting ◽  
Inorganic Perovskite ◽  
Perovskite Quantum Dots ◽  
Reasonable Choice

ABSTRACTApplication of lead-halide perovskite nanostructures for photovoltaic and light emitting applications depends on fashion of the surface termination. The reasonable choice of surface ligands for perovskite nanostructures prevent formation of trap states and contribute to chemical stability, wide opening of the bandgap, and intensity of absorption and photoluminescence of perovskite nanostructures. This work provides atomistic arguments for dual ligand protocol of surface passivation of fully inorganic perovskite quantum dots with fully organic ligands being a mix of cations (ethyl-ammonium) and anions (acetic) in nearly equal proportions. Computed binding energies of either individual ligands or anion-cation pairs demonstrate high stability in comparison to thermal energy and are concluded to be favourable choice in synthesis of colloidal perovskite quantum dots for light emitting applications.

Polycrystalline Si nanocorals/CdS quantum dots composited solar cell with efficient light harvesting and surface passivation

2014 ◽  
Vol 608 ◽  
pp. 314-318 ◽  
Author(s):  
Wuliang Feng ◽  
Yawen Wang ◽  
Jie Liu ◽  
Xibin Yu
Keyword(s):  
Quantum Dots ◽  
Solar Cell ◽  
Surface Passivation ◽  
Light Harvesting ◽  
Cds Quantum Dots

scholarly journals Role of surface passivation on visible and infrared emission of Ge quantum dots formed by dewetting

2019 ◽  
Vol 42 (2) ◽  
Author(s):  
M Aouassa ◽  
M A Zrir ◽  
I Jadli ◽  
L S Hassayoun ◽  
R Mghaieth ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Surface Passivation ◽  
Infrared Emission ◽  
Ge Quantum Dots

Investigation of the role of cadmium sulfide in the surface passivation of lead sulfide quantum dots

2004 ◽  
Vol 270 (3-4) ◽  
pp. 380-383 ◽  
Author(s):  
Mark Fernée ◽  
Andrew Watt ◽  
Jamie Warner ◽  
Jamie Riches ◽  
Norman Heckenberg ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cadmium Sulfide ◽  
Lead Sulfide ◽  
Surface Passivation ◽  
Lead Sulfide Quantum Dots

The Enhancement of Band Edge Emission from ZnS/Zn(OH)2 Quantum Dots

2000 ◽  
Vol 642 ◽  
Author(s):  
Hatim Mohamed El-Khair ◽  
Ling Xu ◽  
Xinfan Huang ◽  
Minghai Li ◽  
Xiaofeng Gu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Surface Passivation ◽  
Band Edge ◽  
Band Edge Emission ◽  
Trap States ◽  
Edge Emission ◽  
Surface Trap ◽  
Quantum Size ◽  
Transmission Electron

ABSTRACTWurtzite structure monodisperse ZnS quantum dots (QDs) of 1 to 5 nm diameter, synthesized by colloidal chemical method, were confirmed by transmission electron microscopy (TEM) images and electron diffraction (ED) patterns. Enhanced blue shifted band edge emission from Zn(OH)2 capped ZnS QDs with decreasing size has been observed, which indicates the role of inorganic surface passivation and hence supports the quantum size effect. Detectable far-red shifted emission from bare ZnS QDs has been observed when QDs precursors and stabilizer dispersed in solvents with different polarities. This emission is attributed to the surface trap states of different energies.

Hybrid dye sensitized solar cell based on single layer graphene quantum dots

2020 ◽  
Vol 175 ◽  
pp. 108118 ◽  
Author(s):  
Farhad Jahantigh ◽  
S.M. Bagher Ghorashi ◽  
Amir Bayat
Keyword(s):  
Quantum Dots ◽  
Solar Cell ◽  
Graphene Quantum Dots ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Dye Sensitized Solar Cell ◽  
Dye Sensitized ◽  
Layer Graphene

Role of PEGylated CdSe-ZnS quantum dots on structural and functional properties of electrospun polycaprolactone scaffolds for blood vessel tissue engineering

2021 ◽  
Vol 151 ◽  
pp. 110430
Author(s):  
Soumya Columbus ◽  
Diksha Painuly ◽  
Renjith P. Nair ◽  
V. Kalliyana Krishnan
Keyword(s):  
Tissue Engineering ◽  
Quantum Dots ◽  
Blood Vessel ◽  
Functional Properties ◽  
Structural And Functional Properties

Kesterite Thin‐Film Solar Cell: Role of Grain Boundaries and Defects in Copper–Zinc–Tin–Sulfide and Copper–Zinc–Tin–Selenide

2021 ◽  
pp. 2100039
Author(s):  
Lingam Sravani ◽  
Soumyaranjan Routray ◽  
Kumar Prasannajit Pradhan ◽  
Maykel Courel Piedrahita
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Grain Boundaries ◽  
Thin Film Solar Cell ◽  
Tin Sulfide ◽  
Copper Zinc Tin Sulfide ◽  
Tin Selenide ◽  
Copper Zinc
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